Lithium-ion battery pack of 2011 Nissan Leaf, showing cells assembled into modules
There are three main paths to improving batteries for future electric vehicles.
One is the development of entirely new technology replacing today's batteries entirely with something lighter, more powerful and more energy dense. The next is the greening of batteries--reducing their environmental impact.
The other is simply to find incremental improvements in today's technology--like eliminating some of its current weaknesses.
Scientists at the University have discovered that as the batteries are used, they slowly lose lithium, as it accumulates outside the battery electrodes.
It turns out the "missing" lithium is accumulating inside the 'current collector'--a copper sheet which improves the efficiency of electron transfer between the electrodes--in addition to the known collection on the outside of the anode.
"We didn’t set out to find lithium in the current collector," explained Bharat Bhusan, Professor of Mechanical Engineering, "...so you could say we accidentally discovered it, and how it got there is a bit of a mystery. As far as we know, nobody has ever expected active lithium to migrate inside the current collector."
Researchers at Ohio have been studying the degredation of batteries, but discovered the lithium collections almost by accident.
The knowledge could now lead to improvements in technology, ensuring more lithium ions move efficiently between anode and cathode when the battery is charging and discharging--rather than collecting elsewhere.