Kevin Drum writes a bit about John McCain’s proposal of a $300 million prize for developing a new battery technology for electric cars. What this makes me really wish is that Marie had a blog, because, as a chemical engineer who just received her PhD working on fuel cell catalysts, this is right up her alley. I hope that she or Jeff will pop up in comments and say smart things. And be kind if I say anything dumb.
But at the least I should be able to avoid saying anything as dumb as McCain’s battery-prize proposal. Not that I don’t like batteries, mind you! But if someone were to invent a better one they’d already be poised to make a huge amount of money through its commercialization. Offering prizes for innovation isn’t always a terrible idea — for pharmaceuticals with a limited market of potential users it can make sense due to the huge costs associated with developing and testing a new drug. But everyone in the developed world needs better energy storage technology, and they need it right now. And while it’s important to make sure your new batteries are safe and robust (e.g. they don’t explode too much), that’s still much easier and cheaper to do than it is to conduct a set of double-blind human trials. So sweetening the pot is unnecessary. Anyone who has a good idea about how to build a better battery is already working on the problem.
The other thing to mention is that Drum’s concern over lithium is probably misplaced. Lithium’s great, and a ringer when it comes to batteries. A cell’s energy density is largely determined by the electrical potential between its anode and cathode — the bigger the gap between them, the better. And as you can see from this chart, electrode potentials don’t get much more negative than lithium.
But it’s got its problems, too. Lithium wasn’t incorporated into mass-market batteries for a long time because of its tendency to catch on fire when exposed to air or charged too quickly. And lithium batteries still tend to dramatically lose capacity about 18 months after they roll off the assembly line, mostly without regard to how hard they’ve been used. Both of those problems have and continue to be addressed by brilliant electrochemists, and the lithium polymer batteries we use today are fairly miraculous. But it would probably be a mistake to think that lithium technology will get dramatically better than it currently is.
It’s also worth noting that not all hybrid or electric cars use lithium batteries. In fact, I don’t think many currently do at all — the Prius uses nickel-metal-hydride, a less efficient but longer-lived chemistry. It would just be too expensive to replace the batteries on lithium’s lifecycle. So worries about peak lithium should be tempered with the realization that we can make batteries out of other stuff, too.
But that doesn’t mean we don’t need a better battery. No-combustion vehicles are where everyone agrees we need to go, but they have much more significant battery requirements than hybrids. They have to charge and discharge faster and more completely, both of which are tough on batteries. And they need to provide more total power, too.
Right now the problem looks pretty tough. There are two promising technologies, though. First, nanotechnology and the unbelievably vast electrode surface areas it provides are making ultracapacitors look more and more viable. These devices will never be able to store as much charge as a battery, I don’t think, but they can be charged and discharged very quickly and may not suffer the age-related effects that plague chemical cells. From what I’ve read, they also tend to be built out of less environmentally objectionable materials. As I said, this is no battery replacement, but it may make different kinds of vehicles possible — say, one that’s inductively recharged every few miles by a plate embedded in the road. Or they may just replace the battery’s buffering function in hybrids, and ease the charge/discharge speed problem in EVs.
The other technology is, of course, fuel cells. Marie tells me they’re again falling out of favor, funding-wise, as their recent renaissance falls back in line with a century-long track record of failure to reduce cost and fragility. But it seems inevitable that we’ll have to revisit the technology — there’s just no better way to safely store lots of energy in a vehicle than with hydrocarbons or some other hydrogen-donating chemical system (I’ve heard some sort of ammonia pellet system suggested, too). And if you’re going to store your energy as hydrocarbons (which isn’t to say it has to be pumped out of the ground, of course), fuel cells are the most efficient way to turn it back into usable power.
That’s my understanding of the situation, anyway. Hybrids seem likely to stick around for longer than many people suspect, I think. Electric vehicles may be great for getting around towns, but I think people are going to balk the first time they try to use the A/C and realize just how many watt-hours they’re spending, and how few they have with them on board their petroleum-free car.