John Goodenough, developer of the lithium-ion battery, was in Houston last week to receive the 2017 Welch Award in Chemistry and give the keynote address at the annual Welch Conference.
Goodenough and his colleague, physicist Maria Helena Braga, announced in April that they have developed a low-cost solid-state battery made entirely from a special glass that Braga discovered during research in Portugal. The glass allows the battery to handle many more recharge cycles than a lithium-ion battery. Also, unlike the liquid electrolytes in lithium-ion batteries, it isn’t flammable.
Goodenough, 95, is a professor in the Cockrell School of Engineering at the University of Texas at Austin. Braga is an assistant professor of engineering physics at the University of Porto in Portugal and a senior research fellow at the Cockrell School. They answered some questions from BNEF in Houston:
Q: In April, you announced a solid-state battery cell breakthrough that was heralded by Eric Schmidt, chairman of Alphabet Inc. What’s been the progress since then?
Goodenough: We’ve found a lot of things you can do with the Braga glass. It’s gone 4,000 cycles with negligible resistance. We have been demonstrating not only can you do that with her glass at room temperature, and in fact we can go well below room temperature. She’s been lighting an LED with this battery charging itself for two years. It runs on ambient heat.
Q: What happens next?
Goodenough: We haven’t demonstrated how much capacity and at what rates. People want fast charge. We are trying to demonstrate that we can get a large capacity and a fast rate. With the small coin cells, we’ve been able to get fast rate and it looks very promising, but it’s early days.
We’re waiting for some battery company to come along. We don’t do the development of the battery, that’s the industry’s job. We have not yet reached a licensing agreement with regard to the battery.
Q: It took 11 years for Sony to put the first lithium-ion batteries in products on the market. How long do you expect this to take?
Goodenough: If somebody is confident and really wants to move, we don’t see why it would take more than three to five years to have a good product on the market. The ideas are there, the intellectual property is there. There is an interest in solid-state batteries.
Q: What’s the improvement over lithium-ion?
Goodenough: There are three basic problems with the lithium-ion battery. First, you can’t charge it fast enough. Second, you can’t overcharge it without getting oxygen. And third, it’s got a flammable electrolyte with a window that’s not big enough. If you want energy density, you’ve got to have the voltage times the current. So you form what’s called a solid electrolyte interphase, called an SEI layer, but then you always get a limited cycle life. If you can only cycle it 1,000 times, it means every two years you have to change the battery. You’ve got to get the costs down.
The Braga battery can last 15,000 cycles. If your battery can last 10 years, people will be satisfied. You do need a long cycle life. Because you have self-charge with her electrolyte, and because you have a big window so you don’t need an SEI there, you can get a long cycle life and lower the cost.
Q: How important is this research to transportation and the environment?
Goodenough: You have to remove all the gas that’s coming out of the tail end of these cars. I was amazed to see how many cars there were out on the highway at 6:30 in the morning just in one city [Houston]. In a big city like Beijing or Delhi, people are choking to death already because you don’t have the wind to blow the gases away in the wintertime.
Our dependence on fossil fuels is not sustainable. Modern society has to be liberated from its dependence on fossil fuels.
Q: Where does Tesla fit in?
Goodenough: What Tesla did was anticipate the need that has to come and he was trying to capitalize on that right away, early. But [Tesla Chairman]Elon Musk got to get beyond the liquid electrolyte. He can’t do it with a lithium-ion battery. He can make hybrid cars at high cost but, he can’t get to what will compete with the internal combustion engine.
Q: Are there other battery technologies that are competing with you?
Goodenough: The people in Japan, the people in China, the people in Korea, they’re all announcing that they’re about to put an all-solid state battery and launch an electric car. But they don’t let me know anything about what their electrolyte is.
Q: So if you were guessing where you are in this horse race, you think you’re in the front.
Goodenough: I think so.
Q: What are the key elements when assessing batteries?
Goodenough: Cost, safety, energy density, volumetric energy density. For the grid you don’t worry about volumetric energy density. For something portable like a car, the volumetric energy density is very important or you don’t get the driving range you want. And you really have to have a faster charge. The hybrid cars now, you have to wait overnight.
Q: What about scaling up?
Goodenough: We don’t see an obstacle to the scaleup as long as you can make thin membranes. We don’t yet know how thin we can make it. It has to be under 30 microns to get the rates you want. The scaleup shouldn’t be a problem. The electric car that is competitive with the internal combustion engine will be here in 10 years.