The tricky challenge holding back electric cars

Abstract

Tiny metal deposits called dendrites threaten to curtail the development of rechargeable batteries. But engineers have solutions in sight.Stephen Ornes, Science Writer Gasoline-powered automobiles seem destined for the rearview mirror. In March 2021, the Swedish company Volvo declared that by 2030 it will sell only fully electric cars. Just weeks earlier, Ford had announced plans to go all-electric in Europe by the same year, while GM is aiming for its cars to be fully electric by 2035. Last year, electric vehicles made up less than 3% of all new car sales in the United States, but a recent analysis by BloombergNEF predicts that their global market share will soar to nearly 60% in just 20 years (1).Electric vehicles that can travel long distances and recharge quickly require safe batteries that pack a lot of energy into a small volume. Building those batteries, however, means overcoming a number of challenges.Chief among them is the problem of dendritesdisruptive, spiky growths of metal inside a battery that raise the risk of dangerous discharges.Building a fast-charging battery that can suppress dendrites is a "holy grail problem," says Yi Cui, an engineer at Stanford University in Palo Alto, CA. But recent findings suggest that the dendrite issue is not insurmountable. Experimental efforts to tame dendrites have produced promising, proof-of-concept demonstrations that capitalize on the strengths of lithium batteries while minimizing dendrite risk. These include strategies such as making nanoscale-level changes to the structure of the electrodes, studying the fundamental causes of dendrites, and exploringThe global market share of electric vehicles is set to soar in the coming years. Designing faster-charging batteries that mitigate dendrite deposits will be a key challenge. Image credit: Shutterstock/guteksk7.