By Fabiana Negrin Ochoa

South Korea's SK Innovation Co. has formed a partnership with Solid Power Inc., a battery maker backed by BMW Group and Ford Motor Co., under which it plans to invest $30.0 million in the U.S. company and jointly produce all-solid-state rechargeable batteries for electric vehicles.

The companies announced the deal Thursday, signing a memorandum of understanding and joint development agreement for SK Innovation to produce automotive-scale, all-solid-state battery cells using Solid Power's technology.

Solid Power will license its technology to SK Innovation--an oil-and-chemical company that forms part of the sprawling SK Group conglomerate--to integrate it into its existing cell production.

"The partnership with SK Innovation is designed to validate that Solid Power's all-solid-state production processes are scalable and compatible with existing lithium-ion production technology," Solid Power Chief Executive Doug Campbell said.

The two companies will also work on developing Solid Power's all-solid-state technology further.

Solid-state batteries, which replace liquid electrolytes with a solid, could be transformative for the EV industry if they prove to be more stable and safer than traditional lithium batteries. However they have yet to be mass produced for automotive use due to costs and other considerations. Major companies like Toyota Motor Corp. and Hyundai Motor Co., among others, are working on the technology.

Both BMW and Ford, which in May led a $130 million Series B investment round in Solid Power, have said they plan to use the company's battery technology in future EVs. The two car makers also have joint development agreements with Solid Power.

According to Thursday's statement, SK Innovation will make its $30.0 million investment via a subscription to buy shares in a previously announced private-investment-in-public-equity deal of Decarbonization Plus Acquisition Corporation III, a blank-check company Solid Power is merging with. The merger is expected to be completed in the fourth quarter.

Write to Fabiana Negrin Ochoa at fabiana.negrinochoa@wsj.com

(END) Dow Jones Newswires

10-28-21 0546ET