Abstract:

Alloy negative materials for Li-ion batteries have been paid much attention because of high specific capacity and safety, but the research between alloy negative materials and the electrolytes was very fewIn this work, Cu6Sn5 alloy film electrode has been prepared by electroplating and heat-treatmentResearch result showed that alloy film electrode in LiN(CF₂SO₂)₂(LITFSI) electrolyte presented higher discharge capacity and better cyclic capability than that in LiPF₆ electrolyteCompared to 1mol·L^-1 LiPF₆/PC electrolyte, alloy film electrode in 1mol·L^-1 LITFSI/EC∶DEC(1∶2) electrolyte had lower reaction resistance, larger reaction peak current density and good reversibility for Li+ insertion/desertionThe addition of EC could improve the electrochemical properties of alloy electrode due to the formation of solid electrolyte interface (SEI) film

Key words:

锂离子电池, 负极材料, 合金, 电解液

摘要：

锂离子电池合金型负极材料的研究得到了广泛的关注，但是合金电极与电解液相互作用的研究非常少。本文采用电镀和热处理相结合的方法制备出Cu₆Sn₅合金薄膜电极，研究了各种电解液对电极性能的影响。研究结果表明，合金电极在LiN(CF₂SO₂)₂(LITFSI)为溶质的电解液中表现出比在常用的以LiPF₆作为溶质的电解液中更高的容量和更好的循环性能。合金薄膜电极在1mol·L^-1 LITFSI/EC∶DEC(1∶2)电解液中具有更小的反应电阻和更大的反应电流密度，锂离子在电极上插入和脱嵌的可逆性良好，反应电阻只有在1mol·L^-1 LiPF₆/PC电解液中的1/10。研究结果表明，乙烯碳酸酯(EC)由于在充放电过程中会形成固体电解质界面（SEI）膜，能大幅度提高材料的电化学性能，在锂离子电池中是不可或缺的。

关键词:

锂离子电池, 负极材料, 合金, 电解液