Duration: 01.02.2010 – 31.12.2018

Project management: Dr. Harald Kren

Partner: TU Graz – ICTM (AUT); VARTA Microbattery (GER)

Within the silicon power project negative electrodes for lithium ion cells are established, that allow the partial replacement of traditionally used graphite by silicon. Due to the fact that silicon can store 10 times the amount of lithium compared to graphite, the use of silicon is favorable. Unfortunately the benefit of higher energy densities in such lithium ion cells is linked to lower cycle life caused by the high volume changes of silicon during lithiation. These high volume changes result in high mechanical stress of the electrodes and are connected to capacity losses during prolonged cycling. Furthermore, it is important to ensure good contacting of the silicon particles because of the low electric conductivity.

The goal of the project is to overcome these limitations by an advanced buildup of particles containing silicon and graphite. This materials are used to prepare electrodes that allow the application of silicon/graphite composites in lithium ion cells. In this regard the project also ascribes special importance to the upscale ability and economic and ecological aspects.