高可逆比容量锡负极循环性能的改善

Improvement of cycling property of tin anode with high reversible specific capacity

为了改善锂离子蓄电池中高比容量锡负极的循环性能 ,采用多孔结构、高比表面积的多孔碳材料为载体制备得到Sn/PC复合材料。电化学测试表明 :用该类复合材料制备的电极表现出良好的锂嵌脱能力 ,循环性能比锡类电极有显著提高 ,其循环性能和可逆比容量与复合电极中锡的含量密切相关。第二次循环后复合电极充放电效率接近 10 0 % ,具备较好的充放电倍率特性和较低的嵌、脱锂电位。制备出的复合材料能防止锡嵌、脱锂过程产生的严重体积效应 ,从而提高电极循环性能 。

The Sn/PC composite material was prepared by adopting porous carbon material with porous structure and high specific surface area as matrix in order to improve the cycling property of tin anode with high reversible specific capacity for Li ion battery. The results of electrochemical test show that the electrodes prepared by the composite material have excellent capability of lithium intercalation and de intercalation. Their cycling properties are improved obviously compared with that of tin electrode, and the cycling property and reversible specific capacity is close related to the tin content in composite electrode. Moreover, the charge/discharge efficiency of the composite electrode is nearly 100% after the second cycle, and it has good charge/discharge rate property and low potential for lithium intercalation and de intercalation. The prepared composite material can avoid the bad volume effect during the process of lithium intercalating into tin and de intercalating from tin, and the cycling property of electrode are improved. It provides a new idea for the practicality of alloy anode material with high reversible specific capacity in lithium ion battery.