May 30, 2015
The Power Behind a Clean Energy Future
Posted on Jul 6, 2011
Peter Scheer: This is Truthdig Radio. I’m Peter Scheer and my guest is Seth Fletcher, a senior editor at Popular Science and the author of “Bottled Lightning: Superbatteries, Electric Cars, and the New Lithium Economy.” Let me start by asking you, you know, batteries in general are technology that the general public doesn’t really pay much attention to. They seem to notice that their computers get faster and do so at a great pace, and their lives get more convenient with other technologies, like suddenly we’re video-chatting with each other, but people don’t really think about one of the central technologies that powers all of that. And your book is all about how essential to our future that technology is. Can you just comment on that?
Seth Fletcher: Sure, one of the things that I often say is that we pretty much only think about batteries or talk about them when we complain about them. Sort of an invisible force in our lives that we really do just complain about them, we don’t really often stop to think about how far the technology has actually come, and that’s in part because it progresses more slowly than computer technology, it’s a chemical system, so it’s an incredibly complicated problem, and progress in battery science does not obey Moore’s Law. You get about a 7 percent improvement every year, and that’s held true for decades. But we are now at the point where we have minuscule batteries that can power things like our iPhones or iPads for hours at a time, and now they’re good enough that we’re starting to see some really market-ready electric cars that can hold four or five passengers, get 100 miles on a charge, or in the case of something like the Chevy Volt you have a smaller battery that gets 40 or 50 miles on a charge, and then you have the backup gasoline engine. So they’re an invisible … not invisible … they’re a sort of …
Peter Scheer: Unsexy, unnoticed.
Seth Fletcher: Unsung, unsexy driver of modernity.
Square, Site wide
Peter Scheer: Let me ask you this before we get into sort of the future of batteries. OK, I drive a Prius, which is powered by a nickel metal hydride battery, unless I’m mistaken, and that’s a slightly older battery technology in terms of like cellphones and laptops. They all run on lithium ion batteries, which are just better, right? They can hold a charge, they don’t get that memory [battery memory effect], and you don’t have to charge them a certain way. And the knock on the Prius is that … well, first of all let me just say since we’re on lithium ion versus nickel metal hydride, so the batteries in my Prius aren’t as volatile as the batteries in my laptop? Is that true? You hear these stories about exploding laptops and that kind of thing with lithium ion batteries.
Seth Fletcher: Yeah, I mean that is true, I believe. But there are various sub-chemistries in lithium ion. What’s in our laptops and cellphones are called lithium cobalt oxide, and it just refers to the compound that’s used in the positive electrode. And that has the advantage of storing a lot of energy, but the safety is not as great as you get with some other chemistries. So because of that reason, the Nissan Leaf and the Chevy Volt, for example, use a strain of lithium ion called lithium manganese oxide, and again, that’s just the active ingredient in the positive electrode. It’s a little less energy dense than the chemistries used in our laptop batteries, but it’s safer. And it also has the benefit of not containing cobalt, which is expensive and toxic and comes largely from the Congo. So within the family of lithium ion batteries, and then even more broadly within the category of rechargeable lithium batteries, there are a lot of different sub-chemistries. But the interesting thing is that nickel metal hydride came out about a year before lithium ion batteries were first commercialized in 1991, and lithium ion caught on very quickly in consumer electronics just because it does have better energy density. But car markers have been kind of slow to move to it in part because of memories of things like exploding laptops.
Peter Scheer: Which are, we should say, you know, given how many laptops are out there, it’s sort of one of those local news stories that freaks people out, but …
Seth Fletcher: Right, during the big Sony episode in 2006, there were I think probably fewer than 10 incidents and nobody was killed, and I’m not even sure that anybody was seriously injured.
Peter Scheer: Out of millions of batteries.
Seth Fletcher: Yeah, billions really. Well, actually, I’m not sure if that’s true it’s billions in that set for Sony, so I should be careful there. But billions of these batteries are manufactured and distributed every year and we carry them around all the time, but understandably carmakers have to be cautious about what they’re going to put in a moving vehicle, and there’s a big difference between a three-ounce lithium battery and a 600-pound lithium ion battery. There’s a lot more energy in that space.
Peter Scheer: So getting back to the cars, one of the knocks on the Prius by Prius haters, and I just use Prius in the sense of hybrid of electric cars, has been, oh you think you’re doing such a great deed for the environment, but these batteries are really a dirty technology. You write also that even if these batteries were filled or produced by a coal plant, they’d still be better than gasoline. So I guess there are two questions here: One is how are the batteries made? What goes into shipping them around the world? That kind of a thing? And, also, how they’re powered, because they’re powered at some point by dirtier, dirty technologies, right?
Seth Fletcher: Right, those are two issues that you have to separate, but they’re worth keeping in mind. I mean, it’s important to, of course, keep in mind everything that goes into a car, and you have to balance the whole equation and not just look at what comes out of the tailpipe. In a case of the Prius with nickel metal hydride batteries, nickel metal hydride batteries contain some lanthanum in them, which is a rare earth metal and, I believe, I could be wrong about this, but I believe the electric motor in the Prius also contains rare earth metals and those are mined almost exclusively in China right now. The mining and refining production dredges up thorium, uranium, so they are radioactive tailings. Rare earth mining is a pretty nasty process and there has been a big push to come up with batteries in select motors that don’t use rare earth metals at all, ideally.
Peter Scheer: But it’s getting cleaner?
Seth Fletcher: Yeah, so the raw materials that go into it are cleaner at the mine site. So lithium is actually very environmentally benign the way it’s mined; it’s basically just sucked up from water that’s absorbed into these salt flats in South America, and it’s left to bake in the sun until it gets concentrated and they process it into a chemical powder. There is an industrial process for manufacturing the electrode power that happens almost entirely in China, Japan and Korea. But the raw materials that go into a lithium ion battery, well, there are no rare earth metals that go into them and there are no toxic metals, there’s no mercury, lead, cadmium, cobalt …
Peter Scheer: And that’s what’s in the Volt and the Leaf.
Seth Fletcher: And that’s in the Volt and the Leaf, of course. There is cobalt in the batteries that we use in all of our portable electronics.
Peter Scheer: So what about powering these devices? Where does that power come from, and why is that cleaner going into a battery than anything else?
Seth Fletcher: The way that these things are compared if you look at emissions per mile driven, and you look at the amount of carbon dioxide that’s generated to power a mile down the road in a car like, let’s say, the Nissan Leaf, versus the CO2 admissions generated by a gas engine going the same mile. What you find is that if an electric car is powered exclusively by really dirty coal energy, it’s still a little better than gasoline; it’s not extraordinarily better, but if you look at the energy mix of the United States as a whole, because we use a lot of hydropower and natural gas, it’s definitely cleaner, and there are a lot of ways to tweak that equation. If you talk about, in the Pacific Northwest, for example, where there is a lot of hydropower, then it’s very, very low emissions and if we can ramp up the amount of renewable, solar and wind, in the grid, or even natural gas is much better than coal, and even more modern coal plants are better than some of the oldest, nastiest coal plants. So that’s a knock that I hear against electric cars often, and it is only legitimate to a certain degree. An electric car powered exclusively is not dramatically better than, say, a 40-mile, three-gallon car like the Fiesta, but that’s really the worst-case scenario. What we need to be doing of course is upgrading our energy infrastructure by moving to cleaner sources and transmitting them more intelligently. And then you add electric cars into that mix and then, you know, electric cars are a piece of the entire system that has to evolve.
Peter Scheer: My guest is Seth Fletcher, author of “Bottled Lightning: Superbatteries, Electric Cars, and the New Lithium Economy.” So tell me about the lithium air battery.
Seth Fletcher: So this is sort of the dream, the ultimate goal, and depending on the disposition of people you’re talking to, they’ll either laugh when you mention it or get really excited and say, I think we can do this. The reason it’s so attractive, and without getting too technical, it just operates on the reaction of lithium with oxygen. There are a bunch of different ways you can put that together, but this reaction offers, theoretically, really really high energy densities, up to 11,000 watt-hours per kilogram. Gasoline is 13,000 watt-hours per kilogram. Today’s lithium ion batteries are somewhere between 150 and 200 watt-hours per kilograms, and that makes the math sound really, really grim, but the thing to keep in mind, of course, is that cars that are powered by internal combustion engines only convert a fraction of the energy-containing gasoline to work. So if you want to match gasoline, you really need to get to about 2,000 watt-hours per kilogram, and lithium air seems to be the best hope for possibly achieving that. Now is it possible? I don’t know. There are a lot of really hard technical problems. Some people are skeptical to think it could be overcome, but it’s not impossible. No one has proven that it’s impossible; we don’t even know if there are showstoppers yet. In fact, I just heard last week that some of the people at IBM that I spoke to when I was working on the book are saying that they’ve made significant strides just in the past year and a half that they’ve figured out a way to recharge, which is one of the hardest problems with lithium air, and that they want within three years or so to be working on a demonstration battery of some sort to prove the concept. So there’s progress happening all the time, but it’s a hard technical program. But if it could be cracked with the lithium air, is the sort of “holy grail” battery, to use a worn cliché.
Peter Scheer: For an extended interview with Seth Fletcher, look for today’s show post on truthdig.com. Again he is a senior editor at Popular Science and author of “Bottled Lightning: Superbatteries, Electric Cars, and the New Lithium Economy.”
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