Solid Power Turns Industrial Waste Into Solid-State Batteries

---

Last week, Solid Power and SK Innovation announced a joint venture to develop solid-state batteries that use a sulfide-based electrolyte developed by the Colorado based startup. Under the agreement, the two firms will work together to develop and produce solid-state batteries with an energy density of at least 930 watt-hours per liter — enough to provide a driving range of up to 930 kilometers on a single charge.

On his way home from his meeting with SK Innovation, Solid Power founder and CEO Doug Campbell spoke with Kim Byung-wook of the Korea Heraldabout the new business relationship and how it will benefit both companies. During the interview, he shared some intriguing insights about the new technology his company is working on.

Campbell said petrochemical companies create lots of hydrogen sulfide, a highly toxic gas. To them it is a waste product that costs them money to get rid of. But to Solid Power, it is a raw material for their sulfide-based solid-state batteries. “A company like SK (Innovation) produces tons and tons of hydrogen sulfide gas and right now they have to pay to dispose of it. You could potentially take what is now a liability and turn it into an asset,” Campbell said.

Under the new partnership, SK Innovation could supply its waste hydrogen sulfide gas to Solid Power. Asked what Solid Power could offer in return, the CEO said, “acceleration,” without a moment of hesitation. “If this partnership continues to work in the manner we anticipate, we anticipate mass production (of solid-state batteries) well before 2030, absolutely.”

SK Innovation has the most conservative timeline for the commercialization of solid-state batteries of the three Korean battery manufacturers. Samsung SDI and LG Energy Solution are targeting production in 2027 while SK Innovation’s target is 2030, Kim writes.

Four Key Components

Solid-state and lithium-ion batteries are made of four key components — cathodes, anodes, electrolytes, and separators. The major difference is solid-state batteries contain solid electrolytes instead of semi-liquid electrolytes. Hydrogen sulfide gas is the raw material for the solid electrolytes developed by Solid Power. This simple change in chemistry makes solid-state batteries that are potentially lighter, more powerful, and fireproof.

Solid Power replaces the cobalt and nickel used in traditional lithium-ion batteries with pyrite — a combination of iron and sulfur that is inexpensive and abundant in nature. “Lithium-ion batteries are dominated by the cost of nickel and cobalt. Pyrite is incredibly cheap,” Campbell said.

“I jokingly say it’s as cheap as dirt because it literally is dirt. So the cost, and I’m not exaggerating when I say this, can be reduced by 90 to 95 percent.

“Coming from Colorado, there’s pyrite everywhere. The whole mountains are full of pyrite, it’s everywhere. And so from our perspective, we view the pyrite to work as being a game changer more for economic reasons.”

To reach energy densities as high as 500 watt-hours per kilogram or more, solid-state batteries require new chemistries, and pyrite is one of the most promising candidates. With existing solid-state chemistries, Campbell said, “The math doesn’t work out.”

Compared to traditional lithium-ion batteries, which have to be kept at or below 35 degrees Celsius in order to have an acceptable service life, pyrite solid-state batteries can withstand heat as high as 70 degrees Celsius without degrading. “As they can tolerate heat, we and our automaker partners believe that there will be no need for pack cooling. That alone is about a 10 percent cost savings,” Campbell said.

Solid Power batteries still have challenges that need to be overcome before they are ready for use in production automobiles. Pyrite solid-state batteries today only operate at low voltage, which makes them incapable of recharged rapidly. “Automakers don’t want to change the original voltage profile. But this can be addressed with bipolar designs which double the nominal voltage, but that needs to be developed,” Campbell said.

As with every story about battery innovation, we need to bear in mind that the road between laboratory breakthroughs and commercial production is fraught with obstacles. For EV advocates, 2030 is too far in the future. We want breakthroughs that bring lower cost batteries with higher power to market today. Batteries made from dirt sound too good to be true, but SK Innovation must see promise in the Solid Power technology to enter into a joint venture agreement with them.

“Any innovative technology that we work on in solid state would eventually come under the umbrella of this cooperation agreement,” Campbell said. That could put SK Innovation in the driver’s seat for the battery industry if Solid Power is successful in perfecting is batteries made from dirt.

The one question we would have asked Campbell if we were sitting in on his interview is why his company needs hydrogen sulfide gas from a company in Korea if the sulfur it needs to make its solid electrolyte can be had almost free for the taking from those mountains in Colorado? Perhaps that is a quibble. Maybe Campbell was talking about production in Korea where pyrite is less abundant rather than production in America. In any event, solid-state batteries are coming, and Solid Power appears to be a leader in the field. Now to see if it can deliver on its promises.