The lithium-ion battery is a cornerstone of consumer electronics. Originating as a power source for camcorders, its utility has spread to smartphones, laptops, and even electronic vehicles.
George Crabtree, senior scientist at Argonne National Laboratory and director of the Joint Center for Energy Storage Research (JCESR), discusses the utility and limitations of lithium ion, the push beyond it, and the environmental future of power.
How do batteries work? Specifically, how do lithium-ion batteries work?
The idea of any battery is to take electrical energy and store it as chemical energy through a chemical reaction.
So, you have the reactants. And when they react, they move to a lower energy level, releasing that energy usually as heat. If you're very clever, you can take it out as electricity instead of heat — and that's what batteries do.
There are many chemical reactions that form batteries and many others that could. We haven't explored them all by any means.
With a lithium-ion battery, the reactant is lithium. It’s very lightweight. And it has one electron that it can give up very easily, so it's extremely reactive.
And that’s kind of a problem in the battery business because, usually, you want it to react with the cathode. But it likes to react with everything else as well. And when it does, it's not storing energy; it's not releasing energy. It's just reacting.
This is a big problem with lithium ion. But, on the other hand, lithium ion is by far the best battery we have ever made. It's very versatile.
I don't think anybody realized in 1991, when Sony brought it out to power the camcorder, how many other things lithium-ion batteries could do.
I noticed on the JCESR site, there’s a push beyond lithium ion.
Yes, there are lots of reasons for that.
Electric vehicles (EVs) need a battery that's 10 thousand times bigger than the one you need for a smartphone or laptop. And you can make the battery 10 thousand times bigger, sure. But it's going to be expensive. In an EV, the battery — just the battery — is something like 25 percent of the purchase price.
And sticking to cars for a minute, you’d like the battery to charge faster; you might worry about its lifetime; and in cold weather, it loses 40 percent of its push, which means 40 percent of its range. Well, in Minnesota in the wintertime, you're going to notice that.
But here’s the main reason to go beyond lithium ion: the grid.
A lithium-ion battery for the grid is typically 1 to 10 thousand times bigger than a battery for an EV. And while they're workable, there's one big limitation. They can discharge at full power for about four hours, maybe six, and that's about it. Again, that’s fundamental to the lithium-ion battery. That’s the way it's made; it can't discharge any longer.
So why is that a problem? If you've got a renewable energy grid — wind or solar — there are many consecutive days of calm and overcast. So, you’ve got to back it up with something. And that something right now is the natural gas peaker plant, which you can run as long as you want. Just keep pumping the gas in it forever.
The downside: It's producing CO2, and that's what we're trying to get rid of. We'd like to have a battery that can discharge longer. And that's one reason to go beyond lithium ion.
There's another reason too. People talk about battery-powered airplanes and drones all the time. As for a regional passenger flight, you could do it with a lithium-ion battery. But if you want anything bigger — transcontinental or transoceanic — it's not going to be lithium ion.
How do batteries factor into the fight against climate change?
One way is transportation. Personal cars are going to go electric, but it'll take a while. People are predicting 40 to 50 percent of new cars could be electric in 10 years.
However, right now, cars are the biggest source of CO2.
You've got to get rid of heavy-duty trucking. Delivery vehicles in cities could become electric, but long-haul trucking probably won't. Shipping on the water probably won't. And airplanes probably won't.
You will need something other than batteries, ultimately, for that.
I read that EVs require more carbon emissions to create than traditional vehicles. Do we need to figure out a cleaner way to produce EV batteries?
Yes. There's no doubt that we do.
Until recently, gigafactories were powered by whatever power was around. And natural gas is a convenient one. You run a gas pipeline up to it, and you get all you want. But as it turns out, how you power the gigafactory makes a big difference in the battery’s carbon footprint.
It was China that was making all the lithium-ion batteries. But, in the last year or two, Europe said, “We have to build gigafactories in order to compete and keep the auto business in Europe.” But they went one step further. They said, “We care about the carbon footprint.”
They looked back at the manufacturing chain to see where the CO2 comes from, and they realized a lot of it comes from making the battery with natural gas power. So they said, “Well, let's do it all with renewable power.”
And one of the first gigafactories that they designed, Northvolt, is supposed to come online in 2024. It's in the northern part of Sweden, chosen because there's lots of hydropower there. They're planning to run the whole gigafactory off hydropower, not CO2. And that dramatically reduces the carbon footprint of the battery.
Overall, there's just a huge disparity. The difference is all the new gigafactories can be renewably powered. And the existing ones, which are mostly in China, are not. Some may be, but that was not a consideration when they were built. So, the business is changing.
What comes after lithium ion? Do we know yet?
Yeah, we do in fact. It's called long-duration discharge storage to protect the grid against consecutive days of cloudy or calm. [One potential long-duration discharge technology] is the redox flow battery.
Instead of a crystal anode and cathode — the two electrodes in any battery — they're liquids. And they store the liquids in big tanks. There’s a pump on each tank, which if needed, pumps the liquid from the two electrode tanks [toward] a membrane. They react by exchanging an anion or a cation across this membrane. So, there’s a chemical reaction going on that stores and releases energy.
And the nice thing about this is you can make the tank as big as you like, so you can store as much energy as you like. Just make the tank bigger. And because it can store so much energy that means it could release at full power for five to six days, or even more. And that's kind of what you need for stabilizing the grid.
The startup Form Energy has promised to deliver, in 2023, a flow battery based on oxygen and water that will discharge at full power for six days. That's way more than a lithium-ion battery. And it's kind of a pilot to see how it works in the real world.
It’s a big step forward toward filling that gap and stabilizing the grid
Is it too late to implement battery technologies in a way that fights the effects of climate change?
Great question. So, some of the things we talked about, like electric cars, have probably a 10-to-15-year deployment run. But it's all commercial, and there's no showstopper there at all.
We don't have a commercial technology for heavy industry and long-distance transportation, boats, and planes. But we do have [electrolyzed water and green] hydrogen.
I just mentioned the Form Energy flow battery, which looks like it might be a solution for long-duration discharge for the grid. That's a big one that we also don't have a commercial technology for now.
Can we develop it all in time for the 2050 net-zero target year? That is a huge challenge, and the timing of science and technology breakthroughs is notoriously hard to predict. There is no doubt that we need an unusual world-wide innovation effort to make that happen.
But it’s my sense that, as climate change gets worse, which it definitely will, we're going to feel the urgency more. So, I think we will be more highly motivated to find solutions; we'll develop more options; and, ultimately, I think we will solve the problem.
It’s impossible to predict when we’ll have a breakthrough. But we do know this for sure: If you put more resources into the R&D, you will get solutions that you didn't think you could get.