Although Tesla and Chevrolet now offer electric cars that can travel nearly as far on a charge as a gasoline-powered car can go on a tank of fuel, the recharge time for EVs has yet to achieve a similar breakthrough. Even Tesla?s ability to recharge a claimed 80 percent of its cars? huge battery packs in as little as 30 minutes is a far cry from the time it takes to fill a tank with gasoline. Now, electronics maker Toshiba has announced it has begun work on a new type of lithium-ion battery geared toward electric cars that can be recharged much, much faster.
The Problem
According to Toshiba, the weak link in today’s lithium-ion batteries, like those used in the Chevrolet Bolt EV (which is capable of DC fast charging) and the Tesla Model S, X, and 3, is the anode portion of the cells. This is the negatively charged electrode, which in most modern lithium-ion batteries is a carbon-based material. During charging and discharging of the battery, ions move between the anode and the cathode, or positively charged electrode. This ion transfer enables the battery to release or take on energy; if you speed up the process too much (as when trying to charge or discharge a battery very quickly), it can suffer excessive degradation. Over time, the transfer of lithium metal between the anode and the cathode can cause increasingly uneven surfaces. Fast charging speeds this up, eventually leading to so much buildup that it can break the separator and bridge the two, causing a short...