Electric pulses rejuvenate batteries

As a battery’s capacity diminishes over time, so, too, does its ability to store and deliver power. Repeated cycles of charging and discharging cause a substantial volumetric change in the electrodes, which leads to their severe structural deformation and pulverization (1). This problem is worse for highcapacity electrode materials that store a large amount of energy, such as lithium and silicon. Active material constituents of such electrodes can detach over cycling time, thereby losing electrical connection to the rest of the battery components. These isolated and electrochemically inactivated components, called isolated active materials, are also often referred to as “dead” supply and contribute to capacity loss (2). On page 322 of this issue, Yang et al. (3) report an approach to recover isolated active materials by applying short electric pulses to the battery. This could be used to recover lost active materials in a broad range of electrode systems to extend the life of a high-capacity battery.