For longer-range EVs, a cousin of silicon makes a material difference

By Yang Jie for Wall Street Journal – Car industry invests billions in silicon carbide for chips that control power, but cost challenges remain.

The global auto industry is investing billions of dollars in chips made of silicon carbide, a more robust cousin of Silicon Valley’s namesake element that companies belive can help them build high-performance electric vehicles.

Silicon carbide, or SiC is silicon married to carbon, the material in a diamond, Using it in chips that contorl power, as Tesla Inc. has done for several years, means less energy gets lost, which in turn leads to a more powerful motor that can drive farther on a single charge.

“Customers of EVs are looking for greater range, and we see silicon carbide as an essential material in the design of our power electronics,” said General Motors Co. Vice President Shilpan Amin this week after GM reached a deal to use silicon-carbide devices made by Durham, N.C.-based Wolfspeed Inc.

This big challenge now is ensuring that the battery cosst savings achieved with silicon carbide chips outweigh the higher cost of making them. Industry observers say companies are making progress bur remain years away from getting the cost close to silicon.

A device based on silicon carbide can be five times as expensive as regular silicon, according to Claire Troadec of French research firm Yole Développement. Among other issues, silicon carbide is harder and more brittle and that means it is more difficult to polish the surface of a silicon-carbide wafer without ruining it… Full article