凯发

Graphene has been widely explored in energy related applications, such as fuel cells, batteries, supercapacitors and hydrogen storage, due to its outstanding physical and chemical properties. When it comes to different energy applications, an advanced modification of pure graphene can lead to significantly enhanced performances. This report will focus on our recent progress of fabricating functionalized graphene-based electrode materials through chemical approaches for high performance Li-ion batteries. On one hand, we fabricated in situ heteroatom doped graphene (e.g., N, S codoped graphene, N-doped graphene) by chemical modification and then annealing, during which the thermal decomposition of heteroatom precursors release a large amount of gas that can effectively prevent the restacking of graphene sheets. Simultaneously, the removal of thermally labile oxygen-containing groups from graphene oxide induces active sites for in situ doping, thus heteroatom doped graphene with single or few layer and porous structure is achieved. Such highly desired structures immediately offer significantly improved Li storage performances in terms of high reversible capacity, long-term cycling stability and excellent rate capability. On the other hand, redox-active functional group grafted graphene-based electrodes were successfully prepared via chemical engineering strategies. The presence of these functional groups is not only beneficial for preventing the restacking of graphene sheets, but can also act as the reservoirs for further Li storage, leading to superb electrochemical performances in Li-ion batteries.