NGK Spark Plug Jumps into Solid-State EV Battery Race

Japan’s NGK Spark Plug Co. is developing a unique chemistry for next-generation, solid-state batteries for electric cars.

Takio Kojima, who heads NGK Spark Plug’s engineering and R&D activities, tells Reuters the company realized seven years ago that an auto industry shift from internal combustion engines to electric motors is “inevitable” and would eventually make NGK’s plug and oxygen sensor businesses obsolete.

The company is capitalizing on its expertise in ceramics to develop an EV battery that will use an oxide-based electrolyte rather than the sulfide-based materials planned by other developers. Solid-state batteries promise more capacity, less weight and faster charging. They also offer better safety than lithium-ion batteries, whose gel-like electrolyte can overheat and catch fire.

Technical challenges remain, Kojima notes. Sulfide electrolytes for solid-state batteries offer stability, high conductivity and tolerance to high temperatures. But they also can emit toxic hydrogen sulfide gas if exposed to moisture.

Kojima says NGK Spark Plug’s devices are even more stable, and they don’t emit dangerous gases. But the devices are less conductive, and their brittle ceramic structure is more difficult to make. The company’s solution includes an unidentified ingredient that brings oxide-based electrolytes closer to the performance levels of sulfide-based electrolytes.

Kojima says NGK Spark Plug also is overcoming the production challenges of making and processing the multi-layered architecture required.