Warwick study claims Li-ion batteries can be charged five times faster

Conducted by researchers at WMG (Warwick Manufacturing Group) at the University of Warwick, the work involved formulating a new precise test for measuring internal battery temperature and electrodes potential. Until now, these important signifiers of charging safety have only been measured externally, leading to imprecise readings and, consequently, conservative manufacturer limits for charging speeds and voltages.

Using an in-situ reference electrode and optical fibre temperature sensor, the WMG team was able to measure the potential of each electrode in a commercially available EV battery, alongside the cell's internal and external temperature. With that data, the researchers could determine how aggressively the battery could be charged while remaining within the thermal and potential safety limits of the cell. It was found that the maximum charging current that could be safely applied was 6.7 times higher than the manufacturer-stated maximum.

Having established the batteries could withstand much higher demands, the team then developed a rapid-charging protocol that leads to more than a five-fold reduction in charging times without compromising safety limits. The research is published in Electrochimica Acta.