Researchers have developed a simple lab-based technique that allows them to look inside lithium-ion batteries and follow lithium ions moving in real time as the batteries charge and discharge, something which has not been possible until now.

The researchers from the University of Cambridge developed a low-cost technique based on optical microscopy called interferometric scattering microscopy to observe the insides of lithium-ion batteries. The method is able to observe how particles of lithium cobalt oxide (LCO) are charging or discharging by measuring the amount of scattered light. This will help to improve existing battery materials and accelerate their developments in the future.

“We found that there are different speed limits for lithium-ion batteries, depending on whether it’s charging or discharging,” said Dr Akshay Rao from the Cavendish Laboratory, who led the research. “When charging, the speed depends on how fast the lithium ions can pass through the particles of active material. When discharging, the speed depends on how fast the ions are inserted at the edges. If we can control these two mechanisms, it would enable lithium-ion batteries to charge much faster.”

Source (University of Cambridge. “Low-cost imaging technique shows how smartphone batteries could charge in minutes.” ScienceDaily. ScienceDaily, 23 June 2021.)

Merryweather, A.J., Schnedermann, C., Jacquet, Q., Grey, C.P. and Rao, A., 2021. Operando optical tracking of single-particle ion dynamics in batteries. Nature, 594(7864), pp.522-528.