Co-Sn合金作为锂离子电池负极材料的研究

CoSn Alloys as Negative Electrode Materials for Lithium-ion Batteries

采用高能机械球磨法合成了富Co的Co3Sn2合金,测试了Co-Sn合金作为锂离子电池负极材料的充放电性能.考察了在机械球磨过程中加入碳和高温处理球磨后样品对合金组成和电化学性能的影响.XRD测试结果表明,加入碳后所得样品的主要成分为CoSn2.于400和600℃处理后主要成分转变为CoSn和Co3Sn2.CoSn2,CoSn和Co3Sn2的充放电容量随着Sn含量的降低依次降低,但循环性能得到提高.

We have prepared a series of Co-Sn alloys by mechanical alloying technology as the negative electrode materials for lithium-ion batteries. The effects of addition of carbon and further heat treatment on the phase composition and the electrochemical performance of the alloys were investigated. X-ray diffraction characterization shows that Co-Sn [ n （Co） ： n （Sn） = 3 ： 1 ] alloys after mechanical alloying can be indexed to the mixture phases of Co3 Sn2 and Co despite of the heat treatment process, however, carbon-added Co-Sn [ n （Co） ： n （Sn） ： n （C） = 3： 1 ： 1 ] alloys consisted of the mixture phases of CoSn2 and Co, and turned to CoSn and Co3Sn2 phase after heat treatment at 400 and 600℃, respectively. The results of charge/discharge test show that the charge/discharge capacity decreases in the following order： CoSn2 〉 CoSn 〉 Co3Sn2 , but the cycling profile was improved.