A discovery by researchers at Ohio State University could help pave the way for better batteries for electric and hybrid cars.
Studying used lithium ion car batteries, Ohio engineers have discovered that as the batteries age, lithium accumulates beyond the battery electrodes – in the “current collector,” a sheet of copper which facilitates electron transfer between the electrodes and the car’s electrical system.
This knowledge could aid in improvements in battery design for cars and lead to enhanced performance and battery life.
Inside, lithium ions shuttle back and forth between the anode and cathode of the battery – to the anode when the battery is charging and back to the cathode when the battery is discharging.
In tests, the group found a ratio of the number of copper atoms in the collector to the number of lithium atoms that had collected there of up to 0.08 percent, or approximately one lithium atom per 1250 copper atoms in the collector.
Previously, the researchers determined that, during ageing of the battery, lithium permanently builds up on the surface of the anode, and the battery loses charge capacity
Bharat Bhushan, Ohio Eminent Scholar and the Howard D. Winbigler Professor of Mechanical Engineering said “This knowledge could aid in improving design and performance of batteries. Our study shows that the copper current collector plays a role in the performance of the battery.”