New Materials for Power Electronics Key in Lowering Cost of Plug-Ins

August 13, 2014

Patrick Ponticel

Lux Research says at 2% power savings, if battery costs fall below $250/kW·h, SiC diodes will be the only economic solution in EVs requiring a large battery, such as the Tesla Model S. However, for plug-in electric vehicles, the threshold power savings needs to be a higher 5%.

As alternatives to silicon (Si), use of wide-bandgap materials (WBGs) such as silicon carbide (SiC) and gallium nitride (GaN) for power electronics in electric vehicles and plug-in hybrid-electric vehicles can have a major impact on systems and overall vehicle costs, according to a Lux Research report. “Efficient power electronics is key to a smaller battery size, which in turn has a positive cascading impact on wiring, thermal management, packaging, and weight of electric vehicles,” said Pallavi Madakasira, Lux Research Analyst and the lead author of the report titled, “Silicon vs. WBG: Demystifying Prospects of GaN and SiC in the Electrified Vehicle Market ( https://portal.luxresearchinc.com/research/report_excerpt/17422 ). A power savings of 20% for the Tesla Model S, for example, could result in cost savings of $6000 in battery cost, or 8% of the vehicle's cost. Lux says SiC could displace Si as early as 2020, and notes that the U.S. Department of Energy’s Advanced Power Electronics and Electric Motors initiative is spending $69 million this year to define performance and cost targets for power electronics; the Japanese government funds a joint industry and university R&D program on power electronics that includes Toyota, Honda, and Nissan.