(浙江大学 材料科学与工程学系, 杭州 310027)
摘 要: 采用机械球磨法将纳米SnO2和Ni粉末复合，作为锂离子电池负极材料。采用XRD、SEM、TEM和EDS分析球磨过程中材料结构和形貌的变化。对SnO2/Ni复合负极材料的首次库仑效率、循环稳定性及CV曲线等进行测试分析。结果表明：将复合粉末球磨适当时间后，SnO2和Ni可形成结合充分、颗粒尺寸细小、分布均匀的复合材料；SnO2和Ni的复合可有效提高SnO2的首次库仑效率和循环稳定性；SnO2/Ni复合负极材料的循环稳定性随球磨时间的延长而增加，但电极的首次库仑效率随球磨时间的延长呈先增加后下降的趋势；Ni的引入有效减小了SnO2在首次充放电循环过程中生成Li2O的不可逆反应程度，并在随后的循环过程中部分以Li−O化合物的形式进行可逆反应。
关键字: 锂离子电池；负极材料；球磨；电化学性能
SnO2/Ni composite anodes for lithium ion batteries
（Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China）
Abstract:Nano SnO2 and Ni powders were ball-milled to form composites as anode materials for lithium ion batteries. The structure and morphology of the composites were analyzed and observed by XRD, SEM, TEM and EDS. The electrochemical properties, including the first coulumbic efficiency, cycle performance and CV curves, were tested. The results show that SnO2 and Ni combine tightly, forming SnO2/Ni composite with small particles. Nano-SnO2 particles disperse uniformly in the Ni-based matrix. The combination of SnO2 with Ni can obviously increase the first coulumbic efficiency and cycle stability of the anode. Moreover, with the increase of the ball-milling time, the first coulumbic efficiency of SnO2/Ni anode first increases then decreases, while the cycle stability almost increases monotonously. The introduction of Ni can reduce effectively the irreversible reaction of SnO2 and Li that forms Li2O and also favors partial Li2O to be reversible in the forms of Li−O compounds in the following cycles.
Key words: lithium ion batteries; anode materials; ball-milling; electrochemical properties
