(浙江大學 材料科學與工程學系, 杭州 310027)
摘 要: 采用機械球磨法將納米SnO2和Ni粉末復合，作為鋰離子電池負極材料。采用XRD、SEM、TEM和EDS分析球磨過程中材料結構和形貌的變化。對SnO2/Ni復合負極材料的首次庫侖效率、循環(huán)穩(wěn)定性及CV曲線等進行測試分析。結果表明：將復合粉末球磨適當時間后，SnO2和Ni可形成結合充分、顆粒尺寸細小、分布均勻的復合材料；SnO2和Ni的復合可有效提高SnO2的首次庫侖效率和循環(huán)穩(wěn)定性；SnO2/Ni復合負極材料的循環(huán)穩(wěn)定性隨球磨時間的延長而增加，但電極的首次庫侖效率隨球磨時間的延長呈先增加后下降的趨勢；Ni的引入有效減小了SnO2在首次充放電循環(huán)過程中生成Li2O的不可逆反應程度，并在隨后的循環(huán)過程中部分以Li−O化合物的形式進行可逆反應。
關鍵字: 鋰離子電池；負極材料；球磨；電化學性能
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
