Scientists at the Department of Energy’s National Accelerator Laboratory charged and discharged coin-sized batteries and different rates, dismantling and analysing their electrodes under an X-Ray at different states of charge to check for degradation.

During rapid charging, only a small part of the electrodes are absorbing and releasing ions, which in turn could lead to cracking and a reduced lifespan. However, this process was spread uniformly across most of the electrodes during rapid discharging.

The results go against conventional wisdom that slower charge and discharge rates are better for batteries than fast ones, and imply that scientists could engineer the materials to absorb and release ions more uniformly to increase the lifespan of a battery.

William Chueh of SIMES, an assistant professor at Stanford's Department of Materials Science and Engineering and senior author of the study, said: ‘The fine detail of what happens in an electrode during charging and discharging is just one of many factors that determine battery life, but it's one that, until this study, was not adequately understood. We have found a new way to think about battery degradation.’