GM and Honda in talks to develop solid-state EV batteries

General Motors Co. and Honda Motor are in talks about expanding their electric-vehicle partnership to include developing solid-state batteries, which automakers are chasing because they have more power, lower cost and reduced risk of fire.

The companies have been discussing joint development of future batteries as they expand cooperation, though no decision has been made yet, Shinji Aoyama, Honda’s managing director for electrification, said in an interview. The two already develop hydrogen fuel cells and EVs together, and Honda is a minority investor in GM’s self-driving vehicle startup Cruise.

“As of now we have not decided to do anything more with GM, but we are discussing semi-solid state and solid-state batteries,” Aoyama said.

Solid-state batteries are seen as a possible breakthrough in electric storage for vehicles. Lithium-ion batteries used in EVs today have a flammable liquid electrolyte that conducts electronics between the cathode and anode. The goal is to replace that liquid with more stable materials like ceramics, which don’t catch on fire and would reduce the size of the pack. They can also store more energy and lose less power in cold weather.

Battery makers have had a difficult time scaling up manufacturing of solid-state batteries for cars, but they have been used in small electronics like pacemakers.

Honda plans to start a small manufacturing pilot in 2024 to prove out its ability to make the batteries and hopes to have them in production in the “late 2020s,” Aoyama said.

A GM and Honda partnership for solid-state storage would deepen their growing relationship. Honda plans to build two mid-sized SUVs using GM’s Ultium battery pack in North America, and the companies have said they plan to jointly produce smaller EVs that could sell a million a year globally.