A simple electrode measurement device could hold the key to ensuring the best performance and life-cycle is gained from lithium-ion batteries.
Scientists at the US Department of Energy’s Argonne National Laboratory used a reference electrode (RE) to enhance the quantity and quality of information on cells during cycling.
By using REs to measure the voltages of individual electrodes the researchers gained insights into cell aging, including the effects of test temperatures and cycling voltages.
Argonne battery researcher Daniel Abraham, is the co-author of the study published in the Journal of The Electrochemical Society.
Abraham’s team found that by sandwiching a Li-Sn RE between the positive and negative electrodes, while simultaneously positioning a pure lithium metal RE next to the stack, they could obtain insights into electrode state-of-charge shifts, active material use, active material loss and impedance changes.
“Such information is critical, especially when developing batteries for larger-scale applications, such as electric vehicles, that have far greater energy density and longevity requirements than typical batteries in cell phones and laptop computers,” he said.
Previously Argonne battery researchers would use only one RE, based on a lithium-tin (Li-Sn) alloy, to collect information.
In testing the new RE configuration, researchers used a cell containing a lithiated oxide cathode, an Argonne-developed silicon-graphite anode and various electrolytes, including ones with fluoroethylene carbonate or vinylene carbonate additives.
Abraham said: ” Our new RE configuration confirms the beneficial impact of these additives, not only in reducing capacity loss but also in mitigating the impedance rise displayed by cells without these additives.”