锡基合金有望替代碳成为新一代高容量锂离子电池的负极材料。Sn-Co合金是研究最为广泛的锡基合金负极材料之一,但该材料存在首次不可逆容量大、循环稳定性差等问题,限制了其实际应用。Sn-Co合金的电化学性能主要受Sn/Co比例、活性材料结晶形态、颗粒尺寸和电极结构等因素影响,纳米材料可提高电极循环稳定性,但易导致较大的首次不可逆容量,而多孔结构的Sn-Co活性材料或多孔结构的电极集流体,有利于电极综合性能的提高。Sn-Co合金中引入碳可明显改善电极的循环容量和循环稳定性。同时综述了Sn-Co合金负极材料的制备方法及其优缺点,并对锡基合金负极材料的发展方向进行了展望。
Sn-based alloys are promising novel anodes for high capacity lithium-ion batteries. Sn-Co alloy is one of the most extensively researched Sn-based anode materials. However, its practical use is limited by the high initial irreversible capacity and unsatisfactory cyclic stability. The electrochemical properties of Sn- Co alloy are mainly dependent on Sn/Co ratio, the crystalline state, particle size of active material and the electrode structure. Nano-materials can improve markedly the cyclic stability, but can easily lead to high initial capacity loss. The porous active material and porous electrode current collector are favorable for the improvement of the overall performance of Sn-Co electrode. The addition of carbon into Sn-Co alloy can enhance significantly the specific capacity and the cyclic stability of electrode. This paper also reviews the preparation methods of Sn-Co anode materials and analyzes their advantages and disadvantages. The development trend of Sn-based alloy anodes is also prospected.