Charging stations alone may not be enough to support California’s shift to electric vehicles, potentially forcing a revolution in their battery design.
California, known for leading the United States in climate regulations, dropped a bombshell last month: By 2035, the state will ban sales of new gasoline powered cars and light trucks. Most new car sales are expected to shift to battery-powered electric vehicles . But along with high prices and modest range, current EVs have another big drawback: They are slow to recharge.
Most EVs today use lithium-ion batteries in which one of the two electrodes, the anode, is made of graphite. Graphite has dominated the market because it’s cheap, abundant, and able to store enough lithium ions to give cars a range of about 500 kilometers. During charging, the applied voltage pushes electrons into the graphite, attracting lithium ions from the other electrode, the cathode.
A partial solution may come from simply changing the rates at which graphite-containing batteries are discharged. In a 23 December 2021 paper, Cui and his colleagues reported that doubling the discharge rate for the first 2 minutes a battery is in use essentially melts away any built-up lithium dendrites, which can extend a lithium-ion battery’s lifetime by 29% and make it stand up better to fast charging.
Other anode materials are also in the works. In 2013, Tolbert, along with UC Los Angeles colleague Bruce Dunn and others, reported that anodes made from the light, gray metal niobium would also enable higher capacity and faster charging than graphite. They processed niobium oxide into a spongelike form, made up of nanoscale tendrils shot through with micron-size pores.