Silicon/Graphene Composites For High-Energy Batteries

For lithium ion batteries, the use of silicon as active material on the negative electrode is most promising, since silicon offers exceptional high volumetric and gravimetric lithium storage capabilities as well as low charging/discharging potentials. However, this high storage capability is accompanied with high volume changes during lithium insertion/extraction, which causes a rapid decay in dimensional stability of the host material (1). The use of graphene-related materials can help to overcome these crucial problems, as graphene offers a highly conductive and mechanically stable matrix that can suppress or buffer this large volume expansion (2) (3). Consequently, graphene-related materials improve the cycling stability by retaining the native structural integrity as well as the electrode porosity.