1 00:00:04,400 --> 00:00:07,800 Speaker 1: Welcome to Text Time, a production from my Heart Radio. 2 00:00:12,200 --> 00:00:15,280 Speaker 1: Hey there, and welcome to tech Stuff. I'm your host, 3 00:00:15,440 --> 00:00:18,880 Speaker 1: Jonathan Strickland. I'm an executive producer with I Heart Radio, 4 00:00:18,920 --> 00:00:22,599 Speaker 1: and I love all things tech, and today we're going 5 00:00:22,720 --> 00:00:27,760 Speaker 1: to go to a listener request. Andrew firmly reached out 6 00:00:27,920 --> 00:00:30,800 Speaker 1: on Twitter and asked if I might do an episode 7 00:00:30,880 --> 00:00:34,800 Speaker 1: about redox flow batteries. That's a topic that I've not 8 00:00:35,040 --> 00:00:38,760 Speaker 1: ever touched upon in more than twelve hundred episodes. So 9 00:00:39,080 --> 00:00:41,320 Speaker 1: when you come up with a chance to do something 10 00:00:41,720 --> 00:00:44,879 Speaker 1: you know new, you jump on it. So thanks Andrew. 11 00:00:45,479 --> 00:00:48,320 Speaker 1: To explain this method of energy storage, I will need 12 00:00:48,400 --> 00:00:51,000 Speaker 1: to refer to a couple of things I have covered 13 00:00:51,040 --> 00:00:55,000 Speaker 1: in previous episodes, so maybe not totally new, but this 14 00:00:55,080 --> 00:00:59,200 Speaker 1: is okay. Let's talk about batteries in general. First. Now, 15 00:00:59,200 --> 00:01:02,320 Speaker 1: I'm not gonna go into the history of voltaic piles 16 00:01:03,000 --> 00:01:08,759 Speaker 1: and their evolution in the to the electrochemical battery of today, 17 00:01:08,800 --> 00:01:12,440 Speaker 1: because I've actually done episodes on those topics already, But 18 00:01:12,520 --> 00:01:14,959 Speaker 1: I do need to talk about what is actually going 19 00:01:15,040 --> 00:01:20,280 Speaker 1: on with a battery, how it generates electricity. The fundamental 20 00:01:20,440 --> 00:01:23,679 Speaker 1: thing that is happening with a battery is that it 21 00:01:23,800 --> 00:01:28,319 Speaker 1: is storing chemical energy and then converts that chemical energy 22 00:01:28,600 --> 00:01:32,800 Speaker 1: into electrical energy. Now we all know energy cannot be 23 00:01:32,920 --> 00:01:37,400 Speaker 1: created or destroyed, but you can convert it from one 24 00:01:37,480 --> 00:01:41,880 Speaker 1: type into another. The classic example of potential energy, you know, 25 00:01:41,880 --> 00:01:44,000 Speaker 1: you've got a rock at the top of a hill. 26 00:01:44,440 --> 00:01:47,520 Speaker 1: Transfer that into kinetic energy. You give the rock a 27 00:01:47,520 --> 00:01:50,960 Speaker 1: little push and it begins to move and gravity pulls 28 00:01:51,000 --> 00:01:53,440 Speaker 1: it downward, and you've got kinetic energy as the rock 29 00:01:53,560 --> 00:01:57,000 Speaker 1: is moving. So that goes from potential to kinetic. Well, 30 00:01:57,240 --> 00:02:02,000 Speaker 1: this case we're talking about chemical to electrical, but still 31 00:02:02,080 --> 00:02:04,600 Speaker 1: same sort of concept, the conversion of energy from one 32 00:02:04,640 --> 00:02:08,800 Speaker 1: format to another. Inside a battery are chemicals that undergo 33 00:02:08,840 --> 00:02:12,440 Speaker 1: a reaction that causes a build up of electrons. Those 34 00:02:12,440 --> 00:02:16,440 Speaker 1: electrons gather at the anode. There are two electrodes on 35 00:02:16,600 --> 00:02:19,760 Speaker 1: a battery, the anode and the cathode. The anode is 36 00:02:19,800 --> 00:02:22,760 Speaker 1: the negatively charged end of the battery. It is the 37 00:02:22,880 --> 00:02:26,880 Speaker 1: end that gives up electrons. So the chemical reaction is 38 00:02:26,919 --> 00:02:31,840 Speaker 1: between essentially the electrode at the anode end and the electrolyte. 39 00:02:31,840 --> 00:02:36,320 Speaker 1: But we also know that like charges repel one another, right, 40 00:02:36,520 --> 00:02:39,480 Speaker 1: two negative charges are going to repel each other. It's 41 00:02:39,480 --> 00:02:42,480 Speaker 1: like putting the north end of two different magnets close 42 00:02:42,560 --> 00:02:45,239 Speaker 1: together and they're gonna push against each other. Same sort 43 00:02:45,240 --> 00:02:49,120 Speaker 1: of thing. So each electron is trying to get away 44 00:02:49,120 --> 00:02:51,640 Speaker 1: from all the other electrons. It's trying to maintain the 45 00:02:51,720 --> 00:02:54,480 Speaker 1: ideal amount of space between it and all of its 46 00:02:54,800 --> 00:02:57,720 Speaker 1: fellow negative nancies. Now on the opposite end of the 47 00:02:57,720 --> 00:03:01,760 Speaker 1: battery is the cathode. This is the positive electrode, the 48 00:03:01,800 --> 00:03:04,920 Speaker 1: positive charge due to its own chemical reactions with the 49 00:03:04,919 --> 00:03:09,239 Speaker 1: electro light. Technically, it's drawing in positively charged ions. The 50 00:03:09,400 --> 00:03:14,000 Speaker 1: ions are atoms that have a net charge, whether positive 51 00:03:14,080 --> 00:03:17,000 Speaker 1: or negative. In this case, they are positively charged ions 52 00:03:17,080 --> 00:03:21,880 Speaker 1: or cat ions. Opposite charges attract each other correct so 53 00:03:22,280 --> 00:03:25,520 Speaker 1: negative attracts positive and vice versa. So that means the 54 00:03:25,560 --> 00:03:29,760 Speaker 1: electrons are attracted to that positive side of the of 55 00:03:29,800 --> 00:03:32,720 Speaker 1: the battery, to the cathode end of the battery. But 56 00:03:32,880 --> 00:03:37,640 Speaker 1: unfortunately for these poor little electrons, between them and the 57 00:03:37,680 --> 00:03:43,000 Speaker 1: cathode where they want to go, there's more door. No wait, sorry, 58 00:03:43,000 --> 00:03:46,920 Speaker 1: I read that wrong. Between them is the electro light, 59 00:03:47,040 --> 00:03:49,160 Speaker 1: which in this case acts kind of like a really 60 00:03:49,200 --> 00:03:53,600 Speaker 1: big bouncer who will explain quite convincingly that the electrons 61 00:03:53,640 --> 00:03:56,280 Speaker 1: are not allowed to cross the line. In an electro 62 00:03:56,440 --> 00:04:01,520 Speaker 1: chemical battery, we typically talk about semi permeable barriers or membranes, 63 00:04:01,920 --> 00:04:05,200 Speaker 1: and these allow some types of particles to go through 64 00:04:05,560 --> 00:04:09,000 Speaker 1: but not others. You can think of it kind of 65 00:04:09,040 --> 00:04:12,840 Speaker 1: like a filter, except this particular filter isn't based on 66 00:04:12,960 --> 00:04:16,719 Speaker 1: particle size. Instead, it's based on particle charge. You got 67 00:04:16,720 --> 00:04:19,400 Speaker 1: a positive charge, Hey, you can come on through, but 68 00:04:19,600 --> 00:04:22,800 Speaker 1: only in one direction? Are you a negative nancy aka 69 00:04:22,960 --> 00:04:27,440 Speaker 1: an electron? Sorry, can't get in boss's orders. So in 70 00:04:27,480 --> 00:04:31,359 Speaker 1: this analogy, the cathode is like a popular nightclub and 71 00:04:31,400 --> 00:04:34,160 Speaker 1: the electrons are folks who really want to get in 72 00:04:34,200 --> 00:04:37,240 Speaker 1: there where the party is, but the bouncer just won't 73 00:04:37,320 --> 00:04:40,560 Speaker 1: let them in. But what if there were a side 74 00:04:40,760 --> 00:04:44,440 Speaker 1: door that was unguarded, Well, then the electrons could take 75 00:04:44,440 --> 00:04:47,960 Speaker 1: a different path to get inside the nightclub. And that's 76 00:04:47,960 --> 00:04:51,240 Speaker 1: what happens. When a battery is placed into a circuit. 77 00:04:51,760 --> 00:04:56,000 Speaker 1: The circuit is a path for electrons, and ultimately the 78 00:04:56,040 --> 00:04:59,000 Speaker 1: circuit will connect the anode end of a battery to 79 00:04:59,080 --> 00:05:01,880 Speaker 1: the cathode end of a battery, though it might not 80 00:05:02,120 --> 00:05:05,320 Speaker 1: be the same battery depending on how the circuit arranges batteries. 81 00:05:05,360 --> 00:05:08,760 Speaker 1: We'll talk about putting batteries in series or in parallel 82 00:05:08,800 --> 00:05:11,600 Speaker 1: in a little bit. So when a path is available, 83 00:05:11,880 --> 00:05:15,360 Speaker 1: the electrons politely tipped their imaginary hats to the electrolyte 84 00:05:15,360 --> 00:05:17,880 Speaker 1: bouncer and then they make their way through the circuit 85 00:05:17,960 --> 00:05:21,320 Speaker 1: to get to that positively charged cathode nightclub, where the 86 00:05:21,320 --> 00:05:25,640 Speaker 1: electrons will rejoin chemicals and another reaction will occur. The 87 00:05:25,680 --> 00:05:28,520 Speaker 1: technical term for this type of chemical reaction in which 88 00:05:28,600 --> 00:05:33,279 Speaker 1: there is an exchange of electrons is a reduction oxidation reaction, 89 00:05:33,880 --> 00:05:37,680 Speaker 1: and we can actually look at those chemical reactions at 90 00:05:37,680 --> 00:05:40,279 Speaker 1: the two electrodes that we talked about earlier as the 91 00:05:40,360 --> 00:05:46,279 Speaker 1: two halves of this reduction oxidation reaction. Reduction refers to 92 00:05:46,480 --> 00:05:51,440 Speaker 1: gaining electrons. That sounds counterintuit if I understand, because typically 93 00:05:51,440 --> 00:05:55,520 Speaker 1: you don't refer to something gaining anything as a reduction, 94 00:05:55,640 --> 00:05:57,719 Speaker 1: but in this case is because we're talking about the 95 00:05:57,760 --> 00:06:01,800 Speaker 1: electric charges here, not sub atomic particles. We're talking about 96 00:06:01,839 --> 00:06:06,160 Speaker 1: the reduction of electric charge going more negative, which would 97 00:06:06,160 --> 00:06:09,720 Speaker 1: happen when you take on an electron. So the component 98 00:06:10,120 --> 00:06:13,919 Speaker 1: is accepting electrons and it undergoes a reduction and electric charge. 99 00:06:13,960 --> 00:06:18,760 Speaker 1: Technically it goes from more positive to typically neutral oxidation 100 00:06:19,080 --> 00:06:23,719 Speaker 1: refers to giving up electrons. When an element oxidizes, it 101 00:06:23,800 --> 00:06:28,640 Speaker 1: is losing electrons. So when iron oxidizes, it rusts, and 102 00:06:28,680 --> 00:06:32,720 Speaker 1: if you break off tiny pieces of iron, they oxidize 103 00:06:32,920 --> 00:06:37,159 Speaker 1: so quickly in the atmosphere, and that chemical reaction gives 104 00:06:37,160 --> 00:06:40,520 Speaker 1: off so much heat it does an exothermic reaction, you 105 00:06:40,640 --> 00:06:44,440 Speaker 1: end up with sparks. There is a faster way to 106 00:06:44,600 --> 00:06:49,719 Speaker 1: say reduction oxidation reactions, and that would be redos. So 107 00:06:49,960 --> 00:06:51,240 Speaker 1: that gives you a hint that we're going to be 108 00:06:51,320 --> 00:06:53,599 Speaker 1: coming back to this when we move on to redox 109 00:06:53,680 --> 00:06:56,640 Speaker 1: flow batteries. But we've got a little bit more finishing 110 00:06:56,680 --> 00:07:00,240 Speaker 1: up to do with classical batteries first. Now, typically the 111 00:07:00,320 --> 00:07:04,559 Speaker 1: circuit the electrons must travel through isn't just an open path. 112 00:07:05,040 --> 00:07:08,680 Speaker 1: We expect those electrons to do some work along the way, 113 00:07:08,720 --> 00:07:11,600 Speaker 1: and the electrons don't really care about that. They just 114 00:07:11,760 --> 00:07:14,440 Speaker 1: want to get to that sweet cathode nightclubs. So we 115 00:07:14,440 --> 00:07:17,800 Speaker 1: tell each electron, hey, buddy, i'm gonna let you in, 116 00:07:18,000 --> 00:07:20,040 Speaker 1: but first i'm gonna need your help to light this 117 00:07:20,160 --> 00:07:23,200 Speaker 1: light bulb or pow are this radio or I don't know, 118 00:07:23,760 --> 00:07:27,200 Speaker 1: give my captain Kirk realistic figuring with real gorn punching 119 00:07:27,240 --> 00:07:31,320 Speaker 1: action the ability to hit that jab, and the electrons 120 00:07:31,360 --> 00:07:34,440 Speaker 1: do this always with the goal of getting through it 121 00:07:34,480 --> 00:07:39,160 Speaker 1: to the cathode nightclub. Doing work is hard, but getting 122 00:07:39,200 --> 00:07:43,040 Speaker 1: past the electro light bouncer is physically impossible. I mean 123 00:07:43,160 --> 00:07:45,880 Speaker 1: in the real sense of the word physics, though I 124 00:07:45,880 --> 00:07:49,640 Speaker 1: guess I really should use chemistry. At least, the electrons 125 00:07:49,720 --> 00:07:53,800 Speaker 1: will do the work if they have the energy necessary 126 00:07:53,920 --> 00:07:57,840 Speaker 1: to do that work. So let's say that in our analogy, 127 00:07:58,200 --> 00:08:00,280 Speaker 1: the work that the electrons have to do is to 128 00:08:00,360 --> 00:08:03,680 Speaker 1: lift a very heavy weight, and the electrons all have 129 00:08:03,840 --> 00:08:08,040 Speaker 1: the same amount of energy or weightlifting ability, but collectively 130 00:08:08,160 --> 00:08:10,440 Speaker 1: their ability is not enough to move that heavy weight. 131 00:08:10,480 --> 00:08:14,120 Speaker 1: They can't budget well. In that case, the battery will 132 00:08:14,200 --> 00:08:17,080 Speaker 1: fail to power the circuit. The electrons will not make 133 00:08:17,120 --> 00:08:19,520 Speaker 1: that journey after all, It's almost as if they ran 134 00:08:19,560 --> 00:08:23,400 Speaker 1: into a second bouncer. So the energy that the electrons 135 00:08:23,520 --> 00:08:27,360 Speaker 1: have is dependent upon the standard potential between the cathode 136 00:08:27,360 --> 00:08:31,000 Speaker 1: and the anode. That is, how great is the difference 137 00:08:31,080 --> 00:08:34,520 Speaker 1: between the negative charge on one side and the positive 138 00:08:34,600 --> 00:08:37,680 Speaker 1: charge on the other side. The greater the difference, the 139 00:08:37,760 --> 00:08:40,880 Speaker 1: greater the potential between the two. This gives us the 140 00:08:40,920 --> 00:08:45,520 Speaker 1: batteries overall electrochemical potential, and that in turn determines the 141 00:08:45,600 --> 00:08:50,400 Speaker 1: voltage of the battery. Voltage is akin to pressure, how 142 00:08:50,480 --> 00:08:54,680 Speaker 1: much force is there in the system pushing those electrons along. 143 00:08:55,200 --> 00:08:58,320 Speaker 1: The force determines whether or not electrons flow. If there's 144 00:08:58,360 --> 00:09:01,000 Speaker 1: not enough voltage, the electrons won't move. If there's a 145 00:09:01,040 --> 00:09:05,000 Speaker 1: lot of voltage, they're gonna move too sweet. So if 146 00:09:05,040 --> 00:09:07,720 Speaker 1: the weight is too heavy, if the load on the 147 00:09:07,760 --> 00:09:11,000 Speaker 1: circuit is too great, then it's going to require greater 148 00:09:11,120 --> 00:09:14,400 Speaker 1: force or voltage to do that work with the same 149 00:09:14,480 --> 00:09:18,720 Speaker 1: amount of electrons. Alternatively, you might be able to do 150 00:09:18,800 --> 00:09:22,640 Speaker 1: that work if you had more electrons a larger volume 151 00:09:22,920 --> 00:09:27,120 Speaker 1: of electrons moving through at that lower voltage. This would 152 00:09:27,160 --> 00:09:30,960 Speaker 1: be a description of current or amperage. But one or 153 00:09:31,080 --> 00:09:33,960 Speaker 1: the other needs to go up. If the electrons are 154 00:09:33,960 --> 00:09:36,480 Speaker 1: going to be able to move that weight to to 155 00:09:36,679 --> 00:09:40,079 Speaker 1: power that load on the circuit, there needs to either 156 00:09:40,200 --> 00:09:42,200 Speaker 1: be more of the electrons, or they need to be 157 00:09:42,240 --> 00:09:45,920 Speaker 1: pushed harder, or you know both. It all depends on 158 00:09:45,920 --> 00:09:48,680 Speaker 1: what the circuit can handle and things like that. So 159 00:09:49,520 --> 00:09:51,880 Speaker 1: you can have a high voltage and a low amperage, 160 00:09:52,040 --> 00:09:53,840 Speaker 1: which means you've got a lot of pressure behind a 161 00:09:53,880 --> 00:09:57,679 Speaker 1: relatively small volume of electrons. Or you could have low 162 00:09:57,800 --> 00:10:01,840 Speaker 1: voltage and high amperage, in which a relatively small amount 163 00:10:01,880 --> 00:10:05,880 Speaker 1: of force is moving a relatively large volume of electrons. 164 00:10:06,400 --> 00:10:09,319 Speaker 1: Or you could have any combination. So your typical household 165 00:10:09,360 --> 00:10:12,520 Speaker 1: batteries have a voltage of one point five and these 166 00:10:12,520 --> 00:10:15,280 Speaker 1: would be your classic double A or triple A batteries 167 00:10:15,320 --> 00:10:18,880 Speaker 1: for example. They're all at one point five volts. Okay, 168 00:10:18,880 --> 00:10:20,679 Speaker 1: But let's say you've got a job and it's going 169 00:10:20,720 --> 00:10:23,600 Speaker 1: to be too much for the battery to handle based 170 00:10:23,640 --> 00:10:28,400 Speaker 1: on that batteries voltage, what are your options. Well, you 171 00:10:28,440 --> 00:10:31,480 Speaker 1: could use a different type of battery if your system 172 00:10:31,559 --> 00:10:35,760 Speaker 1: allowed for that battery that had greater electrochemical potential between 173 00:10:35,760 --> 00:10:38,880 Speaker 1: the two electrodes. But the other option is to stack 174 00:10:38,960 --> 00:10:43,120 Speaker 1: the batteries together in series. This has an additive effect 175 00:10:43,280 --> 00:10:46,000 Speaker 1: on the batteries voltage. Now if you were to connect 176 00:10:46,040 --> 00:10:50,080 Speaker 1: the batteries in parallel instead of in series, So in series, 177 00:10:50,120 --> 00:10:52,680 Speaker 1: you can think of them as one right behind the other. 178 00:10:52,920 --> 00:10:55,760 Speaker 1: In parallel, they're all kind of linked up in their 179 00:10:55,800 --> 00:10:59,480 Speaker 1: own individual pathways into the main circuit. Well, if you 180 00:10:59,520 --> 00:11:02,080 Speaker 1: go in PA Hello, you increase the amperage, you increase 181 00:11:02,160 --> 00:11:05,720 Speaker 1: the current, but not the voltage, so it all depends 182 00:11:05,760 --> 00:11:09,320 Speaker 1: on what you need to do. Now, some batteries can 183 00:11:09,480 --> 00:11:13,480 Speaker 1: only do this process one time through all the way 184 00:11:13,520 --> 00:11:15,880 Speaker 1: through it. So once the cathode nightclub gets full of 185 00:11:15,960 --> 00:11:20,920 Speaker 1: enough electrons, it will lose its positive charge. The electrochemical 186 00:11:20,920 --> 00:11:24,680 Speaker 1: potential between the anode and the cathode will decrease. The 187 00:11:24,720 --> 00:11:27,679 Speaker 1: population of electrons at the anode, entrance of the nightclub 188 00:11:27,679 --> 00:11:32,040 Speaker 1: will diminish, and so even if you have a pathway 189 00:11:32,120 --> 00:11:34,320 Speaker 1: that gives electrons a free and clear entry point to 190 00:11:34,360 --> 00:11:39,199 Speaker 1: the cathode with no load to to work, it won't 191 00:11:39,240 --> 00:11:42,840 Speaker 1: matter because there won't be enough electric potential difference for 192 00:11:43,000 --> 00:11:46,280 Speaker 1: there to be any voltage to be any flow of current. 193 00:11:46,640 --> 00:11:49,160 Speaker 1: So essentially the cathode nightclub has reached kind of a 194 00:11:49,200 --> 00:11:51,520 Speaker 1: neutral charge and no electrons are gonna want to go 195 00:11:51,559 --> 00:11:54,679 Speaker 1: there now because it's some lame spot no one cares about. 196 00:11:55,000 --> 00:11:58,160 Speaker 1: The battery is dead and it needs to be discarded 197 00:11:58,440 --> 00:12:04,080 Speaker 1: or preferably recycled. But other batteries are rechargeable, and putting 198 00:12:04,080 --> 00:12:07,280 Speaker 1: them into a charger means that you're actually introducing an 199 00:12:07,320 --> 00:12:11,200 Speaker 1: incoming electric current into the battery, and it forces this 200 00:12:11,280 --> 00:12:15,560 Speaker 1: reaction to reverse itself. The electrons will bail on the 201 00:12:15,600 --> 00:12:19,880 Speaker 1: Cathode nightclub and return to the anode end, and when 202 00:12:19,920 --> 00:12:22,960 Speaker 1: you remove the battery from the charger, it's back to 203 00:12:23,000 --> 00:12:27,680 Speaker 1: where it was before you used it the first time. Mostly, typically, 204 00:12:27,679 --> 00:12:31,680 Speaker 1: rechargeable batteries recapture only a percentage of the full charge 205 00:12:31,760 --> 00:12:34,600 Speaker 1: they once held, which in our analogy would mean some 206 00:12:34,720 --> 00:12:37,199 Speaker 1: of those electrons were just too much in the groove 207 00:12:37,320 --> 00:12:40,520 Speaker 1: and the Cathode nightclub, so they didn't leave when everyone 208 00:12:40,559 --> 00:12:44,040 Speaker 1: else got kicked out. So over time, even a rechargeable 209 00:12:44,040 --> 00:12:48,319 Speaker 1: battery will lose its ability to store energy. The electrochemical 210 00:12:48,320 --> 00:12:50,720 Speaker 1: potential will become too low for the battery to do 211 00:12:50,800 --> 00:12:52,920 Speaker 1: any useful work. I mean, you might be able to 212 00:12:52,920 --> 00:12:55,000 Speaker 1: hook it up to a meter and say, yes, technically 213 00:12:55,080 --> 00:12:59,319 Speaker 1: current is flowing, but it's at such a small amperage 214 00:12:59,559 --> 00:13:02,800 Speaker 1: that it's not useful for anything. I can't do it 215 00:13:02,840 --> 00:13:05,880 Speaker 1: to light a light bulb or whatever. So that's your 216 00:13:05,880 --> 00:13:09,800 Speaker 1: classic battery. There's another energy storage method we should cover 217 00:13:09,880 --> 00:13:12,080 Speaker 1: as well, as it's going to be useful. When we 218 00:13:12,120 --> 00:13:15,560 Speaker 1: talk about redox flow batteries and that would be fuel cells. 219 00:13:16,280 --> 00:13:20,800 Speaker 1: Fuel cells are similar to, but distinct from batteries. Sir 220 00:13:20,840 --> 00:13:25,320 Speaker 1: William Robert Grove, a Welsh judge, generally gets credit for 221 00:13:25,400 --> 00:13:28,400 Speaker 1: inventing the first fuel cell all the way back in 222 00:13:28,480 --> 00:13:31,800 Speaker 1: eighteen thirty nine. I guess this tells us that Welsh 223 00:13:31,880 --> 00:13:33,880 Speaker 1: judges had a lot of spare time on their hands 224 00:13:33,920 --> 00:13:37,760 Speaker 1: in the mid nineteenth century. Basically, Sir Willie found out 225 00:13:37,800 --> 00:13:41,599 Speaker 1: that by mixing hydrogen and oxygen in the presence of 226 00:13:41,640 --> 00:13:45,400 Speaker 1: an electro light would end up with some interesting byproducts. 227 00:13:45,720 --> 00:13:48,360 Speaker 1: He would get water, you know, good old H two 228 00:13:48,360 --> 00:13:53,320 Speaker 1: O two hydrogens to one oxygen and electricity. But this 229 00:13:53,480 --> 00:13:57,920 Speaker 1: particular incarnation of a fuel cell, well interesting, wasn't practical 230 00:13:58,080 --> 00:14:01,040 Speaker 1: because it wasn't producing enough like tricity to do anything 231 00:14:01,080 --> 00:14:05,160 Speaker 1: of use. However, we're gonna skip way ahead. Fuel Cells, 232 00:14:05,360 --> 00:14:10,280 Speaker 1: like batteries, convert chemical energy into electric energy. There are 233 00:14:10,280 --> 00:14:12,480 Speaker 1: many different kinds, but the ones you and I would 234 00:14:12,559 --> 00:14:15,760 Speaker 1: most likely encounter are those that use hydrogen and oxygen, 235 00:14:16,000 --> 00:14:18,520 Speaker 1: much like Sir Williams fuel cell from more than a 236 00:14:18,600 --> 00:14:22,600 Speaker 1: century ago. In a fuel cell, you've essentially got a 237 00:14:22,640 --> 00:14:27,360 Speaker 1: couple of chambers separated by a semi permeable membrane. In 238 00:14:27,440 --> 00:14:31,280 Speaker 1: one chamber you pump in hydrogen and in the other 239 00:14:31,360 --> 00:14:35,920 Speaker 1: chamber you pump in oxygen. The semi permeable membrane is 240 00:14:36,000 --> 00:14:39,680 Speaker 1: an electrolyte, typically paired with a catalyst, and a catalyst 241 00:14:39,800 --> 00:14:43,240 Speaker 1: is something that facilitates a reaction. It doesn't cause a 242 00:14:43,240 --> 00:14:47,560 Speaker 1: reaction on itself, but it makes reactions easier. It reduces 243 00:14:47,640 --> 00:14:52,640 Speaker 1: the the energy requirement for a reaction to happen. So 244 00:14:52,800 --> 00:14:56,120 Speaker 1: the hydrogen atoms, which consist of one electron and one 245 00:14:56,200 --> 00:14:59,720 Speaker 1: proton that's a hydrogen atom, they react with this electrolyte 246 00:14:59,720 --> 00:15:03,160 Speaker 1: and the catalyst. This causes the hydrogen atoms to say 247 00:15:03,280 --> 00:15:06,880 Speaker 1: bone voyage to that electron. So you get a positively 248 00:15:07,040 --> 00:15:12,520 Speaker 1: charged hydrogen ion or the cat ion, and that would 249 00:15:12,560 --> 00:15:17,880 Speaker 1: be the positive hydrogen uh anions are then negatively charged ions, 250 00:15:17,920 --> 00:15:21,520 Speaker 1: thus like cathode and anode, and we have another word 251 00:15:21,560 --> 00:15:24,880 Speaker 1: for hydrogen ions that would be a proton, because that's 252 00:15:24,920 --> 00:15:28,160 Speaker 1: all a hydrogen nucleus really is. It's one proton, so 253 00:15:28,360 --> 00:15:33,040 Speaker 1: positively charged sub atomic particle. The semipermeable membrane allows the 254 00:15:33,040 --> 00:15:36,280 Speaker 1: proton to pass through it, but not the electron. So 255 00:15:36,360 --> 00:15:39,400 Speaker 1: like our previous example, the electrons really want to get 256 00:15:39,440 --> 00:15:41,720 Speaker 1: to that other side of the membrane because that's where 257 00:15:41,760 --> 00:15:45,160 Speaker 1: a positive charge exists. So you can connect the fuel 258 00:15:45,200 --> 00:15:48,120 Speaker 1: cell to a circuit and the electrons will travel through 259 00:15:48,160 --> 00:15:51,880 Speaker 1: that path and head toward the opposite chamber and they'll 260 00:15:51,920 --> 00:15:54,600 Speaker 1: do work. They'll do work on an electric load along 261 00:15:54,640 --> 00:15:58,560 Speaker 1: the way. How much depends again upon the electrochemical potential 262 00:15:58,840 --> 00:16:02,720 Speaker 1: between the two electrodes, the anode and the cathode. And 263 00:16:02,760 --> 00:16:05,040 Speaker 1: then they'll get over to where all the oxygen and 264 00:16:05,120 --> 00:16:11,080 Speaker 1: hydrogen uh nuclei, the protons, those cat ions all happen 265 00:16:11,160 --> 00:16:13,240 Speaker 1: to be. Now, I have a little bit more to 266 00:16:13,320 --> 00:16:15,920 Speaker 1: say about fuel cells, but before I get into that, 267 00:16:16,040 --> 00:16:26,720 Speaker 1: let's take a quick break. So before we left off, 268 00:16:27,040 --> 00:16:29,760 Speaker 1: I mentioned that the hydrogen in a fuel cell gets 269 00:16:29,880 --> 00:16:34,760 Speaker 1: stripped of its electron. The hydrogen cation or proton, passes 270 00:16:34,800 --> 00:16:38,560 Speaker 1: through this semi permeable membrane. The electron goes through a circuit, 271 00:16:38,720 --> 00:16:41,800 Speaker 1: doing work along the way before finally making its way 272 00:16:41,800 --> 00:16:44,480 Speaker 1: to the other chamber in the fuel cell. In that 273 00:16:44,520 --> 00:16:49,480 Speaker 1: opposite chamber, the protons, electrons, and oxygen combined to form water. 274 00:16:50,080 --> 00:16:53,800 Speaker 1: This is also an exothermic reaction, meaning it gives off heat, 275 00:16:53,920 --> 00:16:58,520 Speaker 1: So your byproducts of this reaction are electricity, heat, and water. 276 00:16:59,120 --> 00:17:02,480 Speaker 1: The fuel cell only generates electricity so long as there 277 00:17:02,600 --> 00:17:06,920 Speaker 1: is hydrogen and oxygen a k a. The fuel that's 278 00:17:07,000 --> 00:17:09,840 Speaker 1: in the cell, and that means that once it runs 279 00:17:09,840 --> 00:17:12,919 Speaker 1: out of those, you have to refuel it. This is 280 00:17:12,960 --> 00:17:16,520 Speaker 1: not something that just stays contained within the fuel cell. 281 00:17:16,760 --> 00:17:19,080 Speaker 1: You're refueling it, just as you would have to refuel 282 00:17:19,160 --> 00:17:21,920 Speaker 1: something like a car, you know, to top it off. 283 00:17:22,359 --> 00:17:25,440 Speaker 1: And it is a clean process within the fuel cell 284 00:17:25,480 --> 00:17:29,880 Speaker 1: itself because the byproduct is pure water. People have advocated 285 00:17:29,920 --> 00:17:32,959 Speaker 1: for fuel cells to replace stuff like gasoline or diesel 286 00:17:33,000 --> 00:17:36,479 Speaker 1: powered vehicles. So what's stopping us? What is in the 287 00:17:36,520 --> 00:17:40,320 Speaker 1: way of doing that? Well, there are a few challenges, 288 00:17:40,520 --> 00:17:43,679 Speaker 1: and one is that hydrogen is actually not that easy 289 00:17:43,720 --> 00:17:46,040 Speaker 1: to come by. Now what do I mean by that? 290 00:17:46,280 --> 00:17:49,440 Speaker 1: I mean, we know hydrogen is the most plentiful stuff 291 00:17:49,440 --> 00:17:52,280 Speaker 1: in the universe, so you figure it would be the 292 00:17:52,320 --> 00:17:54,679 Speaker 1: easiest stuff in the world to get hold of. But 293 00:17:54,880 --> 00:17:59,200 Speaker 1: hydrogen also tends to bond with other stuff. In its 294 00:17:59,240 --> 00:18:03,120 Speaker 1: pure form, hydrogen is a gas and it's lighter than air, 295 00:18:03,160 --> 00:18:06,720 Speaker 1: so it floats off beyond our reach. We typically get 296 00:18:06,800 --> 00:18:11,600 Speaker 1: hydrogen through some other process which involves breaking the molecular 297 00:18:11,640 --> 00:18:15,800 Speaker 1: bonds that hold hydrogen to other elements. But that means 298 00:18:15,840 --> 00:18:19,040 Speaker 1: you have to actually pour energy into this process. In 299 00:18:19,119 --> 00:18:21,320 Speaker 1: order to get to the hydrogen, you have to break 300 00:18:21,359 --> 00:18:25,280 Speaker 1: those molecular bonds. That requires using energy. So to swap 301 00:18:25,320 --> 00:18:28,240 Speaker 1: out to a hydrogen based system, you have to take 302 00:18:28,359 --> 00:18:31,480 Speaker 1: that part into account. Now, if it turns out you're 303 00:18:31,560 --> 00:18:35,200 Speaker 1: using more energy to get the hydrogen, then you would 304 00:18:35,680 --> 00:18:40,600 Speaker 1: get energy by harnessing that hydrogen. You're playing a losing game, right. 305 00:18:40,640 --> 00:18:43,399 Speaker 1: If you're spending more energy just to get the fuel, 306 00:18:43,840 --> 00:18:47,360 Speaker 1: then you are being able to use the fuel. Why 307 00:18:47,400 --> 00:18:49,800 Speaker 1: are you doing that? You should just choose some other method. 308 00:18:50,119 --> 00:18:54,080 Speaker 1: Or if the method you're using to break those molecular 309 00:18:54,119 --> 00:18:59,320 Speaker 1: bonds doesn't depend upon an environmentally friendly method, then really 310 00:18:59,320 --> 00:19:03,080 Speaker 1: you're just shifting pollution to a different part of the system. Now, 311 00:19:03,160 --> 00:19:05,840 Speaker 1: you can get hydrogen out of water by running an 312 00:19:05,840 --> 00:19:09,520 Speaker 1: electric current through the water. In fact, this is essentially 313 00:19:09,720 --> 00:19:13,440 Speaker 1: the same process we see in fuel cells, but in reverse, right, 314 00:19:13,840 --> 00:19:18,400 Speaker 1: because in fuel cells we see hydrogen and oxygen binding 315 00:19:18,440 --> 00:19:23,000 Speaker 1: together and the byproduct in this is electricity and some heat. 316 00:19:23,440 --> 00:19:26,080 Speaker 1: By running an electric current through water, we can break 317 00:19:26,160 --> 00:19:29,040 Speaker 1: up oxygen and hydrogen, and you know, we break that 318 00:19:29,119 --> 00:19:32,520 Speaker 1: molecular bond, so again the same process, but in reverse. 319 00:19:32,840 --> 00:19:36,240 Speaker 1: It's actually called electrolysis. But in order to do that, 320 00:19:36,320 --> 00:19:39,320 Speaker 1: you have to have access to suitable water. You need 321 00:19:39,359 --> 00:19:42,760 Speaker 1: a clean method to generate electricity, maybe use solar power 322 00:19:42,920 --> 00:19:46,360 Speaker 1: or wind power, And all of this starts raising questions 323 00:19:46,359 --> 00:19:48,920 Speaker 1: about why would you not just use solar or wind 324 00:19:48,920 --> 00:19:52,800 Speaker 1: power directly, So you couldn't really do that for like 325 00:19:53,000 --> 00:19:56,040 Speaker 1: an onboard system on a car, and the counter argument 326 00:19:56,119 --> 00:19:57,480 Speaker 1: is that you still have to have a way to 327 00:19:57,600 --> 00:20:01,000 Speaker 1: store energy. Fuel cells would be a way to help 328 00:20:01,119 --> 00:20:05,520 Speaker 1: store energy, but there are other challenges besides the access 329 00:20:05,600 --> 00:20:09,240 Speaker 1: to hydrogen. Another big one is that most fuel cells 330 00:20:09,280 --> 00:20:13,000 Speaker 1: have a band of temperatures within which they can operate, 331 00:20:13,560 --> 00:20:16,600 Speaker 1: and if you get outside that band of temperatures, if 332 00:20:16,600 --> 00:20:18,680 Speaker 1: you go too high or too low, the fuel cell 333 00:20:18,760 --> 00:20:21,920 Speaker 1: will not perform as well and it might even suffer damage, 334 00:20:22,119 --> 00:20:26,000 Speaker 1: which means it will have a much shorter life cycle. Anyway, 335 00:20:26,160 --> 00:20:29,520 Speaker 1: most fuel cells don't operate very well below a certain 336 00:20:29,560 --> 00:20:34,080 Speaker 1: threshold temperature. The specific temperature threshold really depends upon the 337 00:20:34,119 --> 00:20:37,200 Speaker 1: type of fuel cell, and this makes them a little 338 00:20:37,359 --> 00:20:40,399 Speaker 1: less reliable if you want to, I don't know, have 339 00:20:40,560 --> 00:20:44,399 Speaker 1: a fuel cell powered car in Alaska in the middle 340 00:20:44,440 --> 00:20:47,680 Speaker 1: of winter, the temperatures can actually get low enough where 341 00:20:47,720 --> 00:20:51,840 Speaker 1: it's below the real operating temperatures for that fuel cell, 342 00:20:52,240 --> 00:20:54,760 Speaker 1: and it might even do damage to the fuel cells membrane. 343 00:20:54,960 --> 00:20:57,720 Speaker 1: So this is a tricky problem to get around. And 344 00:20:57,800 --> 00:21:01,320 Speaker 1: yet another challenge is that many fuel cells rely on 345 00:21:01,600 --> 00:21:06,600 Speaker 1: rare and expensive materials to act as catalysts, such as platinum. 346 00:21:06,640 --> 00:21:09,680 Speaker 1: And yet another challenge is that many fuel cells rely 347 00:21:09,880 --> 00:21:14,320 Speaker 1: on rare and expensive materials to act as catalysts such 348 00:21:14,320 --> 00:21:19,119 Speaker 1: as platinum. Platinum is expensive stuff, and that drives up 349 00:21:19,160 --> 00:21:22,119 Speaker 1: the cost of manufacturing. As much as I wish we 350 00:21:22,119 --> 00:21:26,000 Speaker 1: could all ignore the impact of money, we can't. If 351 00:21:26,040 --> 00:21:28,960 Speaker 1: you have two ways to store energy, and one is 352 00:21:29,000 --> 00:21:34,040 Speaker 1: relatively cheap but environmentally it's harmful, the other is expensive 353 00:21:34,240 --> 00:21:38,960 Speaker 1: but has no real negative environmental impact, some people, perhaps 354 00:21:39,040 --> 00:21:42,960 Speaker 1: most people, are going to go with the less expensive option, 355 00:21:43,240 --> 00:21:45,600 Speaker 1: even though in the long run you could argue that 356 00:21:45,680 --> 00:21:50,200 Speaker 1: it's more expensive and to have a true hydrogen based economy, 357 00:21:50,640 --> 00:21:52,760 Speaker 1: you would also have to invest in building out a 358 00:21:52,800 --> 00:21:56,960 Speaker 1: new infrastructure, which can run into the billions of dollars, 359 00:21:57,000 --> 00:22:00,960 Speaker 1: so it's another big challenge. Also, I should point out 360 00:22:01,000 --> 00:22:05,320 Speaker 1: that while the actual chemical reaction within a hydrogen based 361 00:22:05,440 --> 00:22:08,640 Speaker 1: fuel cell is a clean one, there can be other 362 00:22:08,720 --> 00:22:13,480 Speaker 1: factors that cause a negative environmental impact, including the mining 363 00:22:13,560 --> 00:22:15,800 Speaker 1: methods that you have to rely on to get the 364 00:22:15,840 --> 00:22:19,400 Speaker 1: materials for the catalyst. You always have to take a 365 00:22:19,440 --> 00:22:22,120 Speaker 1: big picture look at these things and not just look 366 00:22:22,160 --> 00:22:25,600 Speaker 1: at the mechanism of the fuel cell itself. You gotta 367 00:22:25,600 --> 00:22:28,960 Speaker 1: look at the whole ecosystem and say, does this make 368 00:22:29,000 --> 00:22:32,800 Speaker 1: more sense than fossil fuels. I would argue it does, 369 00:22:33,640 --> 00:22:36,200 Speaker 1: but you have to take the whole picture into account 370 00:22:36,240 --> 00:22:39,120 Speaker 1: before you can actually say something like that. And I'm 371 00:22:39,119 --> 00:22:41,920 Speaker 1: not saying all of this to completely dismiss fuel cells, 372 00:22:41,960 --> 00:22:45,520 Speaker 1: because I happen to love fuel cell technology, but I 373 00:22:45,600 --> 00:22:48,680 Speaker 1: also believe we have to acknowledge the obstacles that are 374 00:22:48,720 --> 00:22:50,919 Speaker 1: in our way if we ever are to have a 375 00:22:50,960 --> 00:22:56,120 Speaker 1: hope of surmounting those obstacles. Now, let's finally move on 376 00:22:56,240 --> 00:22:59,639 Speaker 1: to redox flow batteries. Now, luckily, with the grounding we 377 00:22:59,760 --> 00:23:02,960 Speaker 1: have of in traditional batteries and with fuel cells, we 378 00:23:03,000 --> 00:23:06,760 Speaker 1: can tackle this concept a bit more easily. Lawrence H. 379 00:23:06,960 --> 00:23:11,160 Speaker 1: Thaller filed a patent for an electrically rechargeable redox flow 380 00:23:11,200 --> 00:23:15,160 Speaker 1: cell back in nineteen. The Patent Office in the United 381 00:23:15,160 --> 00:23:19,080 Speaker 1: States granted that patent the following year. The abstract gives 382 00:23:19,119 --> 00:23:22,080 Speaker 1: us a really useful starting points, so I'm gonna read 383 00:23:22,119 --> 00:23:25,840 Speaker 1: it in full. Also, this patent expired in so this 384 00:23:25,920 --> 00:23:28,680 Speaker 1: is about as fair use as it gets. But here's 385 00:23:28,720 --> 00:23:33,600 Speaker 1: the abstract. There is disclosed a bulk energy storage system 386 00:23:33,680 --> 00:23:40,280 Speaker 1: including an electrically rechargeable reduction oxidation redox cell, divided into 387 00:23:40,320 --> 00:23:45,000 Speaker 1: two compartments by a membrane. Each compartment containing an electrode 388 00:23:45,359 --> 00:23:48,560 Speaker 1: and anode fluid is directed through the first compartment at 389 00:23:48,560 --> 00:23:51,920 Speaker 1: the same time that a cathode fluid is directed through 390 00:23:51,920 --> 00:23:55,600 Speaker 1: the second compartment, thereby causing the electrode in the first 391 00:23:55,640 --> 00:23:59,119 Speaker 1: compartment to have a negative potential while the electrode in 392 00:23:59,160 --> 00:24:03,040 Speaker 1: the second compart mint has a positive potential. The electrodes 393 00:24:03,160 --> 00:24:07,280 Speaker 1: are inert with respect to the anode and cathode fluids used, 394 00:24:07,480 --> 00:24:11,840 Speaker 1: and the membrane is substantially impermeable to all except select 395 00:24:11,920 --> 00:24:15,560 Speaker 1: ions of both the anode and cathode fluid. Whether the 396 00:24:15,600 --> 00:24:19,080 Speaker 1: cell is fully charged or in a state of discharge. 397 00:24:19,560 --> 00:24:23,440 Speaker 1: Means are provided for circulating the anode and cathode fluids, 398 00:24:23,600 --> 00:24:26,639 Speaker 1: and the electrodes are connected to an intermittent or non 399 00:24:26,720 --> 00:24:31,399 Speaker 1: continuous electrical source, which, when operating, supplies current to a 400 00:24:31,480 --> 00:24:34,119 Speaker 1: load as well as to the cell to recharge it. 401 00:24:34,600 --> 00:24:39,000 Speaker 1: And sillery circuitry is provided for disconnecting the intermittent source 402 00:24:39,240 --> 00:24:42,439 Speaker 1: from the cell at prescribed times and for circulating the 403 00:24:42,440 --> 00:24:46,760 Speaker 1: anode and cathode fluids according to desired parameters and conditions. 404 00:24:47,240 --> 00:24:49,760 Speaker 1: And that's the abstract. Now. I'm sure a lot of 405 00:24:49,760 --> 00:24:52,200 Speaker 1: you out there are way up to speed with what's 406 00:24:52,240 --> 00:24:55,240 Speaker 1: going on. But for those of us like me who 407 00:24:55,280 --> 00:24:57,760 Speaker 1: find the language of patents to be a teen c 408 00:24:58,160 --> 00:25:01,720 Speaker 1: bit difficult to parse, let's break it down, and we're 409 00:25:01,720 --> 00:25:05,359 Speaker 1: gonna start with the core, the cell of this flow 410 00:25:05,440 --> 00:25:10,400 Speaker 1: battery where the electricity gets generated. This core has two compartments, 411 00:25:10,480 --> 00:25:14,520 Speaker 1: each with its own electrode. One electrode the anode, is 412 00:25:14,560 --> 00:25:18,399 Speaker 1: the negative terminal, the other, the cathode, is the positive terminal. 413 00:25:18,720 --> 00:25:21,200 Speaker 1: And this is just like a battery or a fuel cell. 414 00:25:21,560 --> 00:25:25,280 Speaker 1: A liquid electrolyte pumps into each side of the core. 415 00:25:25,680 --> 00:25:28,719 Speaker 1: In between the two compartments is a membrane separates the 416 00:25:28,720 --> 00:25:32,440 Speaker 1: two cores. In between the two compartments is a membrane 417 00:25:32,480 --> 00:25:35,760 Speaker 1: that separates those two compartments, right, it's right there in 418 00:25:35,800 --> 00:25:40,440 Speaker 1: the middle, and it allows certain ions, certain charged particles 419 00:25:40,480 --> 00:25:45,760 Speaker 1: to pass through, but not electrons. These compartments connect to 420 00:25:45,840 --> 00:25:51,160 Speaker 1: respective electrolyte tanks, so big reservoirs, and the tanks hold 421 00:25:51,200 --> 00:25:56,320 Speaker 1: the positive or negatively charged ions. Pumps on either side 422 00:25:56,840 --> 00:26:01,240 Speaker 1: take the respective electrolyte from the respect tank and pump 423 00:26:01,280 --> 00:26:05,159 Speaker 1: it into the respective compartment in the cell, and then 424 00:26:05,440 --> 00:26:08,720 Speaker 1: within the cell, the ion exchange can happen across the 425 00:26:08,760 --> 00:26:13,640 Speaker 1: membrane the anode side or the analyte because that's anode 426 00:26:13,640 --> 00:26:18,000 Speaker 1: plus electrolyte releases electrons in this process, which then can 427 00:26:18,040 --> 00:26:20,080 Speaker 1: go on and do work in a circuit before joined 428 00:26:20,080 --> 00:26:24,400 Speaker 1: the cathode plus electrolyte on the other side. The respective 429 00:26:24,680 --> 00:26:28,399 Speaker 1: liquid electrolytes now continue to move out of the cell 430 00:26:28,880 --> 00:26:33,679 Speaker 1: and back into their various tanks. However, this means that 431 00:26:33,720 --> 00:26:37,440 Speaker 1: the electrolytes are now chemically different because of that ion 432 00:26:37,600 --> 00:26:41,159 Speaker 1: and electron exchange. They're no longer the same ions that 433 00:26:41,240 --> 00:26:43,679 Speaker 1: they were when they were being pumped into the cell 434 00:26:44,000 --> 00:26:47,840 Speaker 1: and having that exchange right now they're inert, at least 435 00:26:47,840 --> 00:26:50,960 Speaker 1: with respect to each other. They no longer will have 436 00:26:51,080 --> 00:26:55,359 Speaker 1: that reaction. You won't have that electrochemical potential where that 437 00:26:55,480 --> 00:26:58,920 Speaker 1: exchange could happen again. So let's say you've pumped through 438 00:26:59,240 --> 00:27:03,800 Speaker 1: the entire air supply of electrolyte through both tanks. You know, 439 00:27:03,960 --> 00:27:06,840 Speaker 1: it's been pumped all the way through and refilled, and 440 00:27:06,920 --> 00:27:10,919 Speaker 1: now we've got these inert electrolytes. You would eventually find 441 00:27:11,040 --> 00:27:14,679 Speaker 1: you are no longer producing any electricity because enough of 442 00:27:14,720 --> 00:27:17,840 Speaker 1: the electro light has gone through this exchange that the 443 00:27:17,920 --> 00:27:20,720 Speaker 1: electric potential between the cathode and anode is no longer 444 00:27:21,160 --> 00:27:24,840 Speaker 1: sufficient for that to continue. So it's kind of like 445 00:27:25,040 --> 00:27:29,440 Speaker 1: having a dead battery. However, this process can be reversed, 446 00:27:29,880 --> 00:27:32,520 Speaker 1: just as with a rechargeable battery. So if you pour 447 00:27:32,800 --> 00:27:36,399 Speaker 1: the electricity into the system, you cause the reverse of 448 00:27:36,400 --> 00:27:40,359 Speaker 1: this chemical reaction. You recharge the electrolytes that are on 449 00:27:40,440 --> 00:27:43,800 Speaker 1: either side, that are in either compartment, so that once 450 00:27:43,840 --> 00:27:46,760 Speaker 1: again you have negatively charged electro light on the anode 451 00:27:46,800 --> 00:27:50,040 Speaker 1: side and positively charged electro light on the cathode side, 452 00:27:50,440 --> 00:27:53,679 Speaker 1: And you would pump these electro lights through the cell, 453 00:27:54,320 --> 00:27:57,280 Speaker 1: they would get recharged then they would go back into 454 00:27:57,359 --> 00:28:00,840 Speaker 1: their tanks, so you're gradually reach our ing all the 455 00:28:00,880 --> 00:28:04,200 Speaker 1: electro light that are in either tank until your back 456 00:28:04,280 --> 00:28:08,720 Speaker 1: up to full capacity. This reminds us that batteries are 457 00:28:08,720 --> 00:28:11,719 Speaker 1: not a source of energy. They are a form of 458 00:28:12,000 --> 00:28:15,959 Speaker 1: energy storage. We have to put energy into them in 459 00:28:16,080 --> 00:28:19,639 Speaker 1: order to get energy out, so we're not like mining 460 00:28:19,920 --> 00:28:23,560 Speaker 1: electricity here. And now we're getting into how these batteries 461 00:28:23,640 --> 00:28:25,840 Speaker 1: might be used. So let's say you've got a farm 462 00:28:26,000 --> 00:28:29,240 Speaker 1: of solar panels and they're generating electricity. It's a bright 463 00:28:29,280 --> 00:28:34,600 Speaker 1: sunny day and they're generating electricity like gangbusters. That electricity 464 00:28:34,680 --> 00:28:38,239 Speaker 1: needs to either be put to work immediately or it 465 00:28:38,280 --> 00:28:41,239 Speaker 1: has to be stored otherwise it goes to waste. And 466 00:28:41,280 --> 00:28:44,320 Speaker 1: this is true of any method of generating electricity, by 467 00:28:44,320 --> 00:28:47,880 Speaker 1: the way, not just with solar panels, but with traditional 468 00:28:47,920 --> 00:28:51,280 Speaker 1: power plants. Our power plants try to match production to 469 00:28:51,320 --> 00:28:54,680 Speaker 1: meet demand, but sometimes demand is low, such as say 470 00:28:54,720 --> 00:28:57,000 Speaker 1: in the middle of the night when most folks sleep, 471 00:28:57,320 --> 00:29:00,000 Speaker 1: and the power plants then have options. They can try 472 00:29:00,120 --> 00:29:04,000 Speaker 1: in store excess energy in some other form and some 473 00:29:04,120 --> 00:29:07,000 Speaker 1: other solution so that it doesn't just go to waste. 474 00:29:07,640 --> 00:29:11,360 Speaker 1: One way of doing This is through hydro pumping, and 475 00:29:11,360 --> 00:29:15,200 Speaker 1: I want to describe this because there's some analogies between 476 00:29:15,280 --> 00:29:19,560 Speaker 1: hydro pumping and redox flow batteries. Hydro Pumping is a 477 00:29:19,600 --> 00:29:23,640 Speaker 1: fairly simple idea. Let's imagine that you've got two reservoirs 478 00:29:23,800 --> 00:29:26,840 Speaker 1: of water, but one is at a higher elevation than 479 00:29:26,880 --> 00:29:30,200 Speaker 1: the other, so it's up a hill. From the higher reservoir, 480 00:29:30,640 --> 00:29:33,360 Speaker 1: you have a tunnel. This is called the intake tunnel. 481 00:29:33,760 --> 00:29:37,160 Speaker 1: That tunnel leads down into a powerhouse under the ground, 482 00:29:37,480 --> 00:29:40,960 Speaker 1: and that powerhouse contains a turbine that water can turn. 483 00:29:41,040 --> 00:29:45,080 Speaker 1: So water flowing down due to gravity hits this turbine 484 00:29:45,600 --> 00:29:48,240 Speaker 1: and the force of it causes the turbine to rotate. 485 00:29:48,440 --> 00:29:53,400 Speaker 1: This powers and electrical generator, generating electricity. As the name implies. 486 00:29:54,040 --> 00:29:57,280 Speaker 1: The water then continues to flow out a second tunnel, 487 00:29:57,440 --> 00:30:00,640 Speaker 1: the discharge tunnel, and this tunnel empty is out into 488 00:30:00,680 --> 00:30:05,440 Speaker 1: the lower reservoir. So effectively, water is just flowing downhill, right. 489 00:30:05,480 --> 00:30:08,080 Speaker 1: It's coming from an upper reservoir down through a tunnel. 490 00:30:08,200 --> 00:30:10,440 Speaker 1: Happens to have to do some work along the way, 491 00:30:10,640 --> 00:30:13,160 Speaker 1: and then continues down until it hits the lower reservoir. 492 00:30:13,840 --> 00:30:17,720 Speaker 1: It just needs gravity to work. But to recharge the system, 493 00:30:17,960 --> 00:30:21,520 Speaker 1: the powerhouse turbine has to actually be activated. We have 494 00:30:21,600 --> 00:30:24,800 Speaker 1: to pour energy into it and turn the turbine in 495 00:30:24,840 --> 00:30:28,560 Speaker 1: the opposite direction. Now it's acting like a pump, and 496 00:30:28,640 --> 00:30:32,200 Speaker 1: it forces water from the lower reservoir and pumps it 497 00:30:32,320 --> 00:30:36,640 Speaker 1: up against gravity into the upper reservoir. So when a 498 00:30:36,680 --> 00:30:41,680 Speaker 1: power plant is generating more electricity than the current demand requires, 499 00:30:42,080 --> 00:30:46,120 Speaker 1: it could send that excess electricity over to the hydro 500 00:30:46,240 --> 00:30:49,400 Speaker 1: pump station. The hydro pump station activates and begins to 501 00:30:49,440 --> 00:30:52,680 Speaker 1: pump water from the lower reservoir into the upper reservoir, 502 00:30:53,160 --> 00:30:56,680 Speaker 1: and then they have that energy stored. But if the 503 00:30:56,720 --> 00:31:00,240 Speaker 1: power plant ends up seeing a demand for electric see 504 00:31:00,280 --> 00:31:04,240 Speaker 1: that exceeds its own ability to produce electricity, the hydro 505 00:31:04,320 --> 00:31:07,120 Speaker 1: pump can jump into action and it can open up 506 00:31:07,120 --> 00:31:11,360 Speaker 1: those tunnels and allow gravity to have water turn a generator, 507 00:31:11,560 --> 00:31:15,680 Speaker 1: and thus you get to augment the power plants capability 508 00:31:15,720 --> 00:31:21,880 Speaker 1: of producing electricity. So again it's just storing energy. Well, 509 00:31:22,200 --> 00:31:24,240 Speaker 1: the same sort of thing is happening with the redox 510 00:31:24,280 --> 00:31:28,400 Speaker 1: flow batteries and for much the same purpose, except instead 511 00:31:28,440 --> 00:31:31,960 Speaker 1: of using gravity and kinetic energy to provide what we need, 512 00:31:32,400 --> 00:31:36,640 Speaker 1: we're talking about an electrochemical process. We're still using pumps 513 00:31:36,680 --> 00:31:40,920 Speaker 1: to circulate liquid electrolyte from reservoirs through an electric cell, 514 00:31:41,000 --> 00:31:45,160 Speaker 1: but we discharge the redox flow battery by having this 515 00:31:45,240 --> 00:31:48,959 Speaker 1: ion exchange, and the active elements in these reservoirs begins 516 00:31:49,000 --> 00:31:52,720 Speaker 1: to reduce and we recharge by reversing the process, we 517 00:31:52,880 --> 00:31:56,520 Speaker 1: pump electricity back into the battery to recharge the respective 518 00:31:56,520 --> 00:31:59,680 Speaker 1: electrolytes so that the tanks are full of active components. 519 00:32:00,240 --> 00:32:03,360 Speaker 1: The capacity of a redox flow battery depends upon the 520 00:32:03,480 --> 00:32:08,040 Speaker 1: size of those tanks. The electrochemical potential of a redox 521 00:32:08,080 --> 00:32:11,560 Speaker 1: flow battery will always depend upon the specific electric lights 522 00:32:11,600 --> 00:32:13,080 Speaker 1: being used. It doesn't matter if you have more or 523 00:32:13,120 --> 00:32:16,920 Speaker 1: less of them, So you choose your electrolytes that's going 524 00:32:16,960 --> 00:32:20,560 Speaker 1: to determine that electrochemical potential. So in other words, that 525 00:32:20,600 --> 00:32:23,760 Speaker 1: determines what the voltage of your battery is going to be. 526 00:32:24,120 --> 00:32:26,120 Speaker 1: And it doesn't matter if you have small tanks full 527 00:32:26,160 --> 00:32:28,200 Speaker 1: of the stuff or big tanks full of the stuff. 528 00:32:28,720 --> 00:32:33,120 Speaker 1: The difference is that the size of the tank determines 529 00:32:33,200 --> 00:32:37,880 Speaker 1: the capacity, the amount of energy overall that it can store, 530 00:32:38,640 --> 00:32:41,120 Speaker 1: and that depends not just on the size of the tank, 531 00:32:41,160 --> 00:32:45,320 Speaker 1: but also on which electro lights you choose. Some electro 532 00:32:45,440 --> 00:32:49,760 Speaker 1: light pairings are more energy dense than others. Some are 533 00:32:49,800 --> 00:32:52,760 Speaker 1: more energy dense but much more toxic, or they're more 534 00:32:52,760 --> 00:32:55,200 Speaker 1: expensive or both. So there are a lot of different 535 00:32:55,200 --> 00:32:58,720 Speaker 1: considerations you have to make when you're choosing your electrolytes. 536 00:32:59,080 --> 00:33:01,600 Speaker 1: But the size of the banks you're really just limited by. 537 00:33:02,080 --> 00:33:05,440 Speaker 1: You know, your facility, and if you have the facility 538 00:33:05,480 --> 00:33:08,840 Speaker 1: to make a truly enormous pair of tanks, then you've 539 00:33:08,840 --> 00:33:12,240 Speaker 1: got a battery that's got an enormous capacity to store energy. 540 00:33:12,920 --> 00:33:15,360 Speaker 1: They're not going to release that energy all at once, 541 00:33:15,680 --> 00:33:17,800 Speaker 1: but it's going to store a lot of it. And 542 00:33:18,000 --> 00:33:21,720 Speaker 1: like traditional batteries, you can actually connect redox flow batteries 543 00:33:21,760 --> 00:33:24,520 Speaker 1: in series, so you can create a higher voltage that 544 00:33:24,520 --> 00:33:27,840 Speaker 1: way too. Instead of having to swap out what electrolytes 545 00:33:27,880 --> 00:33:30,640 Speaker 1: you plan on using, you could just make a series 546 00:33:30,720 --> 00:33:33,600 Speaker 1: of these redox flow batteries and get a higher voltage 547 00:33:33,640 --> 00:33:36,320 Speaker 1: by connecting them that way. Now, when we come back, 548 00:33:36,400 --> 00:33:38,360 Speaker 1: I'll talk a bit more about some of the types 549 00:33:38,400 --> 00:33:41,640 Speaker 1: of electrolytes used in these redox flow batteries, since again 550 00:33:41,680 --> 00:33:44,400 Speaker 1: it determines the voltage as well as the use cases 551 00:33:44,440 --> 00:33:47,480 Speaker 1: for the batteries and some recent advancements in that technology. 552 00:33:47,520 --> 00:33:57,120 Speaker 1: But first let's take a quick break. So from the 553 00:33:57,160 --> 00:34:00,400 Speaker 1: moment they were first invented in the late sick season 554 00:34:00,520 --> 00:34:04,160 Speaker 1: and patented in the seventies to present day, the choice 555 00:34:04,200 --> 00:34:07,040 Speaker 1: of which materials to use as the anode and cathode 556 00:34:07,040 --> 00:34:11,120 Speaker 1: electrolytes have guided the evolution of the redox flow battery. 557 00:34:11,440 --> 00:34:16,640 Speaker 1: Early redox flow batteries included a zinc chlorine pairing chlorine 558 00:34:16,680 --> 00:34:21,800 Speaker 1: is incredibly dangerous stuff, zinc bromine, Later zinc serrium batteries 559 00:34:21,800 --> 00:34:25,840 Speaker 1: were used. Vanadium based redox flow batteries have been used, 560 00:34:26,239 --> 00:34:28,480 Speaker 1: and lots of others, and they have a range of 561 00:34:28,520 --> 00:34:33,200 Speaker 1: capabilities when it comes to stuff like electrochemical potential, energy density, 562 00:34:33,239 --> 00:34:37,920 Speaker 1: power density, toxicity, cost, and recycling. Recycling by the way, 563 00:34:37,960 --> 00:34:41,719 Speaker 1: I don't mean to recycle the materials, but rather how 564 00:34:41,719 --> 00:34:46,520 Speaker 1: many recharge cycles does this battery have? How many times 565 00:34:46,560 --> 00:34:49,120 Speaker 1: can you charge it back up to full and discharge 566 00:34:49,160 --> 00:34:54,760 Speaker 1: it in full and not lose any energy storage capacity. 567 00:34:55,120 --> 00:34:59,880 Speaker 1: Rarer elements are obviously more expensive, that's kind of a given, 568 00:35:00,360 --> 00:35:03,920 Speaker 1: and some of these are actually more like hybrid style 569 00:35:04,040 --> 00:35:07,600 Speaker 1: redox flow batteries which require some extra components, or they 570 00:35:07,600 --> 00:35:11,359 Speaker 1: include specially treated electrodes where one of the two electrodes 571 00:35:11,680 --> 00:35:15,120 Speaker 1: has UH elements on it that make it either the 572 00:35:15,120 --> 00:35:18,040 Speaker 1: anode or the cathode. The zinc ones also have to 573 00:35:18,080 --> 00:35:21,879 Speaker 1: contend with a tendency for zinc to coat the electrodes. 574 00:35:22,160 --> 00:35:26,200 Speaker 1: You get almost like an electro plating, but it's of zinc. 575 00:35:26,480 --> 00:35:28,719 Speaker 1: And if that happens enough, then the electrodes has become 576 00:35:28,800 --> 00:35:33,279 Speaker 1: less effective. They're no longer able to transmit electrons, so 577 00:35:33,320 --> 00:35:37,400 Speaker 1: you eventually have to strip those plates of that zinc coding. 578 00:35:37,880 --> 00:35:42,160 Speaker 1: More recently, researchers with the University of Southern California announced 579 00:35:42,200 --> 00:35:44,759 Speaker 1: that they were working on a redox flow battery that 580 00:35:44,920 --> 00:35:49,080 Speaker 1: uses an iron sulfate solution, and that is super cheap 581 00:35:49,160 --> 00:35:52,400 Speaker 1: to get hold of because it's a byproduct from the 582 00:35:52,440 --> 00:35:57,400 Speaker 1: mining industry. It's essentially waste. So the other component in 583 00:35:57,480 --> 00:36:01,640 Speaker 1: this particular approach is an acid called an stick with 584 00:36:01,760 --> 00:36:07,000 Speaker 1: me guys an through quine known disulfonic acid and I'm 585 00:36:07,040 --> 00:36:10,040 Speaker 1: sure I mess that up, but it's a q DS 586 00:36:10,200 --> 00:36:12,160 Speaker 1: is how everyone refers to it, because no one wants 587 00:36:12,160 --> 00:36:15,560 Speaker 1: to say that name. Now, one major advantage of this 588 00:36:16,239 --> 00:36:19,279 Speaker 1: entire approach that the University of Southern California researchers have 589 00:36:19,480 --> 00:36:23,839 Speaker 1: suggested is cost because the components are plentiful and they 590 00:36:23,840 --> 00:36:27,960 Speaker 1: are inexpensive, so it brings down the cost per kill 591 00:36:28,000 --> 00:36:32,960 Speaker 1: a lot hour of providing electricity using this method, and 592 00:36:33,040 --> 00:36:36,560 Speaker 1: that's a big deal. Now. In addition, these batteries again 593 00:36:36,600 --> 00:36:41,560 Speaker 1: have different cycle capacities, so that whole discharge recharge cycle 594 00:36:42,080 --> 00:36:46,280 Speaker 1: redox flow batteries typically have hundreds or thousands of cycles, 595 00:36:46,960 --> 00:36:51,000 Speaker 1: sometimes between ten and twenty thousand cycles, which means that 596 00:36:51,080 --> 00:36:53,839 Speaker 1: you can use the same supply of liquid electrolytes over 597 00:36:53,880 --> 00:36:56,799 Speaker 1: and over. In fact, some people say that they effectively 598 00:36:56,880 --> 00:37:01,840 Speaker 1: have an indefinite number of recharge icals. It's really the 599 00:37:01,920 --> 00:37:05,440 Speaker 1: other components that you have to frequently swap out, like 600 00:37:05,840 --> 00:37:08,279 Speaker 1: you will eventually have to replace the pumps or you 601 00:37:08,320 --> 00:37:11,200 Speaker 1: may have to replace the electrodes or the membrane, but 602 00:37:11,280 --> 00:37:13,879 Speaker 1: that the electro light fluids for a very long time 603 00:37:13,920 --> 00:37:17,200 Speaker 1: will just be stable. The redux flow battery is good 604 00:37:17,239 --> 00:37:20,520 Speaker 1: for the load balancing applications that I mentioned earlier with 605 00:37:20,560 --> 00:37:24,080 Speaker 1: power grids, and compared to some other battery technologies like 606 00:37:24,200 --> 00:37:28,080 Speaker 1: lead acid or lithium ion batteries. Redux flow batteries tend 607 00:37:28,080 --> 00:37:32,520 Speaker 1: to have lower power and energy densities. They can't hold 608 00:37:32,560 --> 00:37:36,360 Speaker 1: as much, but they work well with large applications like 609 00:37:36,400 --> 00:37:41,520 Speaker 1: power grids, and they scale right, so there's a balance there. However, 610 00:37:41,560 --> 00:37:44,080 Speaker 1: the requirements of the redux flow battery are such that 611 00:37:44,120 --> 00:37:46,959 Speaker 1: they are not good for smaller applications, which you could 612 00:37:46,960 --> 00:37:49,200 Speaker 1: easily imagine. Right, you're not going to have these for 613 00:37:49,680 --> 00:37:54,560 Speaker 1: your cell phone. They're not good for portable or tiny applications. 614 00:37:54,640 --> 00:37:57,279 Speaker 1: The requirement of the reservoir tanks means this tech does 615 00:37:57,320 --> 00:38:01,120 Speaker 1: not scale down well. You would want this for large 616 00:38:01,280 --> 00:38:04,880 Speaker 1: stationary applications, so you could pair it with stuff like 617 00:38:04,960 --> 00:38:07,760 Speaker 1: green or energy technologies like I had mentioned before the break, 618 00:38:07,840 --> 00:38:11,080 Speaker 1: like the solar panel farm, because with wind power or 619 00:38:11,120 --> 00:38:14,520 Speaker 1: solar power, redox flow batteries can help balance out the 620 00:38:14,640 --> 00:38:19,080 Speaker 1: natural drawbacks of those methods. We know the sun doesn't 621 00:38:19,120 --> 00:38:22,120 Speaker 1: shine all the time because that slacker takes practically every 622 00:38:22,120 --> 00:38:26,239 Speaker 1: single night off, nor does the wind always blow. So 623 00:38:26,480 --> 00:38:30,160 Speaker 1: using energy storage to help balance the load during times 624 00:38:30,160 --> 00:38:34,480 Speaker 1: where you cannot easily produce electricity directly is critical. You 625 00:38:34,560 --> 00:38:37,120 Speaker 1: need some way to store the energy when you're producing 626 00:38:37,160 --> 00:38:39,920 Speaker 1: a lot of it and some way to release the 627 00:38:40,000 --> 00:38:42,879 Speaker 1: energy when you're not able to produce it. And that's 628 00:38:42,920 --> 00:38:46,719 Speaker 1: really one of the key elements for going with a 629 00:38:46,719 --> 00:38:51,439 Speaker 1: renewable green energy source. Bringing the cost down on that 630 00:38:51,719 --> 00:38:55,440 Speaker 1: energy storage makes renewable energy solutions much more viable. It's 631 00:38:55,480 --> 00:38:59,359 Speaker 1: a it's a key component of doing that. And as 632 00:38:59,360 --> 00:39:01,520 Speaker 1: I mentioned earl here, if you have a renewable method 633 00:39:01,600 --> 00:39:05,160 Speaker 1: to generate electricity and you have one that relies on, say, 634 00:39:05,200 --> 00:39:09,600 Speaker 1: fossil fuels, and you've got a pretty high price tag 635 00:39:09,640 --> 00:39:11,520 Speaker 1: for your renewable energy, it's hard to get a lot 636 00:39:11,560 --> 00:39:14,840 Speaker 1: of people to switch, or maybe hard to get large 637 00:39:14,880 --> 00:39:20,520 Speaker 1: power companies to switch. After all, the economically viable option 638 00:39:20,680 --> 00:39:23,359 Speaker 1: is to go with the lower cost so you get 639 00:39:23,640 --> 00:39:26,799 Speaker 1: higher return. You don't want to spend more money and 640 00:39:26,840 --> 00:39:30,400 Speaker 1: make less money, at least not from the perspective of business. 641 00:39:30,840 --> 00:39:33,680 Speaker 1: If we take that from a perspective of environmental impact, 642 00:39:33,719 --> 00:39:36,200 Speaker 1: there's a different argument to be made. But we have 643 00:39:36,280 --> 00:39:38,680 Speaker 1: to remember we live in the real world where all 644 00:39:38,719 --> 00:39:42,680 Speaker 1: of these factors are playing a part making the whole 645 00:39:42,800 --> 00:39:47,960 Speaker 1: enterprise economically advantageous. By enterprise, I mean renewable energy. That's 646 00:39:47,960 --> 00:39:49,960 Speaker 1: a huge move and we're starting to see it already. 647 00:39:49,960 --> 00:39:53,759 Speaker 1: I mean, we've already seen the price of energy production 648 00:39:54,080 --> 00:39:59,799 Speaker 1: through renewable technologies to come down significantly to the point 649 00:39:59,800 --> 00:40:02,640 Speaker 1: where it's actually very competitive with fossil fuels, in some 650 00:40:02,680 --> 00:40:08,040 Speaker 1: cases more advantageous. And having this component, the energy storage component, 651 00:40:08,440 --> 00:40:11,480 Speaker 1: be part of that is critical. But that's pretty much 652 00:40:11,480 --> 00:40:15,279 Speaker 1: all I have to say about REDOS flow batteries. To 653 00:40:15,280 --> 00:40:18,360 Speaker 1: get into more detail would really just involve talking about 654 00:40:18,440 --> 00:40:22,040 Speaker 1: the specific ion exchanges with each pairing of electrolyte materials, 655 00:40:22,800 --> 00:40:26,400 Speaker 1: which would become a chemistry lesson, or talking about how 656 00:40:26,480 --> 00:40:30,239 Speaker 1: much energy those individual electro LTEs hold per unit of 657 00:40:30,360 --> 00:40:33,160 Speaker 1: volume and how expensive they are, which would becomes sort 658 00:40:33,160 --> 00:40:37,200 Speaker 1: of a cost benefit analysis of the different types of electrolytes. 659 00:40:37,680 --> 00:40:40,400 Speaker 1: And really I'm not keen to do either of those things. 660 00:40:40,400 --> 00:40:44,440 Speaker 1: But the important things we've covered the basic technology of it. 661 00:40:44,800 --> 00:40:47,799 Speaker 1: So you're not likely to encounter a flow battery for 662 00:40:47,920 --> 00:40:51,080 Speaker 1: home use, but some large buildings might take advantage of 663 00:40:51,120 --> 00:40:54,960 Speaker 1: one as part of a load balancing UH strategy or 664 00:40:55,280 --> 00:41:00,000 Speaker 1: backup generator strategy. More likely, power plants and renewable energy 665 00:41:00,080 --> 00:41:02,640 Speaker 1: facilities will use them, as I've said, but you never know. 666 00:41:03,160 --> 00:41:06,439 Speaker 1: But I do think it's a pretty interesting technology, one 667 00:41:06,560 --> 00:41:10,040 Speaker 1: that relates very closely to those others that I mentioned before, 668 00:41:10,640 --> 00:41:13,720 Speaker 1: but is different enough where I thought it was cool 669 00:41:13,800 --> 00:41:17,200 Speaker 1: to really tackle it. If you guys have any suggestions 670 00:41:17,280 --> 00:41:19,960 Speaker 1: for me to cover in future episodes of tech Stuff, 671 00:41:19,960 --> 00:41:23,160 Speaker 1: whether it's a specific technology, maybe it's a company or 672 00:41:23,200 --> 00:41:26,319 Speaker 1: a person in tech, Maybe it's just a trend in 673 00:41:26,400 --> 00:41:29,200 Speaker 1: tech that you want to know more about, let me know. 674 00:41:29,480 --> 00:41:31,719 Speaker 1: You can reach out to me on Twitter or Facebook. 675 00:41:31,800 --> 00:41:34,359 Speaker 1: The handle for both of those is text stuff H 676 00:41:34,560 --> 00:41:38,120 Speaker 1: s W and I'll talk to you again really soon. 677 00:41:43,120 --> 00:41:46,120 Speaker 1: Text Stuff is an I Heart Radio production. For more 678 00:41:46,200 --> 00:41:49,600 Speaker 1: podcasts from I Heart Radio, visit the I Heart Radio app, 679 00:41:49,719 --> 00:41:52,880 Speaker 1: Apple Podcasts, or wherever you listen to your favorite shows.