UA researchers: Trapped ions cause batteries to lose power

Although batteries are becoming increasingly powerful, they still lose their effectiveness when they are constantly recharged over a period of time. This limited capacity is one of the burdens of users of mobile devices but also a major reason why consumers aren’t buying electric cars in greater numbers.

Researchers at Antwerp University (UA) and the Collège de France in Paris have pinpointed the cause of this loss of power. Their research results were just published in the science journal Nature Materials.

The researchers examined the newest range of batteries, which work on the basis of lithium-rich layered oxides. “They are 15% more powerful than classic lithium batteries, but the voltage decreases quickly when they need to charged many times,” said professor Staf Van Tendeloo of UA in a statement.

Through advanced electron microscopes, the researchers saw how metal ions “jumped”  back and forth between the layers of metal and the layers of lithium. In the process of charging and discharging, these ions are sometimes trapped in the “cavities in between”, and there are thus fewer “free” metal ions available as the battery ages.

The researchers will now work to solve the problem through methods such as testing different kinds of metal ions.