Lithium-ion batteries withstand 10.000 charging cycles

May 22, 2013 // By Christoph Hammerschmidt
Scientists from the Centre for Solar Energy and Hydrogen Research Baden Wuerttemberg (ZSW) have developed lithium-ion-batteries that could offer new perspectives for electromobility: After more than 10.000 charging cycles, the batteries still had more than 85 percent of its initial capacity.

According to the ZSW, the cycle stability demonstrated in the current project represents a top value within the international competition. Also with regard to the energy density the batteries from Ulm are competitive, the institute said. The technology developed by the ZSW scientists establishes a basis for the production of ouch cells as well as large prismatic cells which could be used as energy storage in electric vehicles and for solar power, believes Dr. Margret Wohlfahrt-Mehrens, head of the section Materials Research for Recharcheable Batteries at ZSW Ulm. "After 10.000 complete charging cycles at a speed of one cycle per hour, our lithium-ion batteries still feature more than 85 percent of its capacity. This also offers a good perspective for the calendric life expectancy."

A long operating life is a requirement of the automotive industry for their electric vehicles. Batteries in lithium-ion technology must be able to survive ten years or more without degrading to less than 80 percent of their initial capacity.

The thorough understanding of the matter helped the scientists to achieve good values also under other aspects: For example, the power density of the cells is about 1.100 watt per kilogram, meeting the international top level. For electric cars, power density translates into short charging cycles and good acceleration.

The next step for the ZSW scientists and engineers will be developing prismatic lithium cells jointly with industrial partners. The implementation of large cells still requires some additional research, said Wohlfahrt-Mehrens, but "in principle upscaling is possible"