BMW Closes In On The Solid State EV Battery Of The Future

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The US government has not been a friend to the vehicle electrification movement this year, to put it kindly. Nevertheless, the pace of zero emission innovation will march on with or without an assist from President Donald Trump. The latest example comes from BMW, which has jumped into the solid state EV battery race with an assist from the US battery materials startup Solid Power and the Korean firm Samsung SDI.

Nothing Can Stop The Solid State EV Battery Of The Future

A solid state EV battery is just what the name says, a battery that replaces the conventional liquid electrolyte with solid materials. Replacing a liquid with a solid poses all sorts of challenges (here’s one example), but the payoff for the vehicle electrification movement is substantial (see more solid state battery background here).

Aside from eliminating fire hazards, a solid state EV battery offers automakers a lighter, more compact, longer lasting, and higher-performing mobile energy storage solution. In short, it helps make the case for owning an EV even stronger than ever before.

With those prizes in mind, battery researchers have been chipping away at the solid state obstacles for a good ten years or so, and all that hard work is about to pay off. Trump or no Trump, the commercialization of a solid state EV battery is a foregone conclusion, and the past month alone has seen a renewed rush of activity.

The US firm QuantumScape kicked things off by pairing up with Corning to fine tune a new high-efficiency manufacturing system for its ceramic battery separator. Toyota followed in short order with a reminder that it expects to launch EVs into the market with solid state batteries within the next two years or so, and then along comes BMW with some news of its own.

BMW Has A Solid State EV Battery Up Its Sleeve

BMW has been eyeballing Solid Power’s solid state solution as far back as 2016. The automaker jumped on the opportunity to invest in Solid Power when it went public in 2021, and BMW further dropped some hints regarding a collaboration with Solid Power earlier this year. They were not kidding around. Under the newest stage of collaboration with BMW, Solid Power will contribute its sulfide-based solid electrolyte to Samsung SDI for use in fabricating solid state battery cells.

The three firms have not released performance parameters and other details of the new agreement, but the cooperative effort is designed to culminate in the launch of a BMW demonstration vehicle.

The road from the laboratory to a demonstration vehicle is a long one. Solid Power has been floating across the CleanTechnica radar on and off since launching in 2011, as a spin-off from research at the University of Colorado-Boulder. The company replaces both the liquid electrolyte and polymer separator with a single layer of a sulfide-based solid material.

“This thin, solid layer acts as a barrier to keep the anode and cathode from touching one another, which would short the battery. It also acts as a conductive electrolyte,” Solid Power explains.

With an eye on containing costs and fostering rapid scale-up, Solid Power designed its solid state electrolyte around earth-abundant materials and ease of manufacturing. The company isn’t saying exactly what kind of sulfides go into its formula. That’s a trade secret! However, but sulfides (compounds of sulfur with other substances) do occur commonly in nature, one particularly abundant example being the sulfur-iron mineral pyrite, also known as fool’s gold.

Sulfides Vs. Ceramics

Those of you familiar with the state of solid state EV battery technology are probably familiar with the challenges posed by sulfide-based electrolytes. QuantumScape, for example, is among the solid state stakeholders that have settled on high tech ceramics as alternative to sulfide-based electrolytes for lithium-metal batteries.

Toyota, in contrast, cites several advantages on the sulfide side, including the potential for scale-up. “Sulfide solid electrolytes are characterized by softness and adhesiveness to other materials, which is suitable for battery mass production,” Toyota also notes. The company has been working with the firm Idemitsu on a lithium sulfide foundation for solid state batteries.

Stellantis is another sulfide-curious automaker. Last year the company hooked up with the US solid state battery startup Factorial Energy, which has developed a sulfide-based electrolyte it calls “Solstice.” Factorial also has an ongoing relationship with Mercedes-Benz.

Next Steps For The EV Battery Supply Chain

The solid state battery of the future aside, the US still needs to secure its EV battery supply chain here and now. That was a difficult task even before Trump took office earlier this year, one key issue being the environmental impact of mining for lithium and other critical materials.

Some workarounds have been emerging, including systems that extract lithium from oil and gas drilling wastewater. The ARPA-E branch of the US Department of Energy has just stepped it up a level with the launch of a new $25 million round of funding for new wastewater-based extraction technologies.

That may seem a bit off-topic for the Trump administration. However, critical materials have broad applications among key US industries. If the auto industry also benefits, so much the better. After all, what’s sauce for the goose is sauce for the gander.

The $25 million pot comes under an ARPA-E program called RECOVER, which is the somewhat forced shorthand for “Realize Energy-rich Compound Opportunities Valorizing Extraction from Refuse waters.”

ARPA-E already anticipates another round of RECOVER funding to follow this week’s announcement. For now, the beneficiaries include The University of Texas – Austin, which will recover lithium and other materials from both oilfield and municipal wastewater.

RECOVER also tasks Johns Hopkins University with recovering two other key EV battery materials, cobalt and nickel, from industrial wastewater from a variety of sources including e-waste recycling facilities, lithium-ion battery factories, produced water from oilfields, and discharges from mining operations.

Considering the Trump administration’s fraught (to put it mildly) relationship with Ivy League schools, one project of particular interest is a $1.655 million award to Columbia University to recover lithium and magnesium from wastewater.

Magnesium (not to be confused with manganese) is a relatively new development in the energy storage field, so stay tuned for more news on that score.

Photo: The US startup Solid Power is contributing its sulfide-based electrolyte to a new solid state EV battery in partnership with BMW and the Korean firm Samsung SDI (cropped, courtesy of Solid Power).