关键词: 三维铜箔集流体, 纳米Sn/SnSb 合金, 三维复合负极, 粘结剂, 导电剂

Abstract: A novel three-dimensional composite anode was prepared by using three-dimensional copper foil with micro-holes for collector and nano-Sn/SnSb alloys powders for active materials. The nano-Sn/SnSb alloys were synthesized by liquid chemical reduction methods at low temperature and the collector was obtained via multiple-step electrodeposition. Advantages of the new three-dimensional composite anode were investigated by comparing its electrochemical performance with that of normal planar anode: three-dimensional structure of the electrode enhanced the combination between active materials and the collector, which increased the possibility for the preparation of anode without binder; the novel anode effectively buffered the volume expansion of high capability active materials during charge/discharge cycles and therefore increased the capacity retention of the electrode. Compared to 33%of the initial charge capacity of normal anode after 30 cycles, the capacity retention of three-dimensional composite anode was 41% of the initial charge capacity; special structure provided a well environment for transferring charge, which made the process of the reaction more complete and therefore higher capacity. The initial specific charge capacity of normal anode was 480 mAh·g-1 and that of three-dimensional composite anode achieved 800 mAh·g-1. The advantages and attractive electrochemical performance of the three-dimensional nano-Sn/SnSb composite anode provide a new thought for structure design and development of anode for lithiumion battery.

Key words: Three-dimensional copper foil collector, Nano-Sn/SnSb alloys, Three-dimensional composite anode, Binders, Conductive agents