Li-CYCLING BEHAVIOR OF Mo-CLUSTER COMPOUNDS,A2Mo3O8 (A = Zn, Co)

摘要：

The compounds, A2Mo3O8 (A=Zn and Co) are prepared by the carbothermal reduction and are characterized by X-ray diffraction (XRD). Electrochemical studies are carried out at ambient temperature by galvanostatic cycling (0.005-3.0 V vs. Li; at 60 mAg-1 (0.12 C)) and cyclic voltammetry (CV). The first-charge reversible capacity, after a deep discharge to 0.005 V, are 350 and 900 (±5) mAhg-1 corresponding to 7.1 and 18 moles of Li/formula unit of Zn2Mo3O8 and Co2Mo3O8, respectively. An initial increase in reversible capacity till 17 cycles and then a decrease to 255 (±5) mAhg-1 (5.2 Li) at the end of 50 cycles is noticed for Zn2Mo3O8. Cycling up to 40 cycles shows a capacityfading of 52%. Interestingly, heat-treated electrodes (300℃, 12 h, Ar) showed better Licyclability and smaller capacity-fading: the reversible capacities are 610 and 805 (±5) mAhg-1 (~12.4 and 16.1 moles of Li) at the end of 50 and 40 cycles for Zn2Mo3O8 and Co2Mo3O8, respectively. After the first few cycles, the coloumbic efficiency reaches 96-98%. A possible reaction mechanism is proposed based on the CV and ex-situ XRD data.

关键词： Co2Mo3O8 Zn2Mo3O8 Carbothermal reduction Li- cycling Mo-cluster

作者: B. DAS M. V. REDDY G. V. SUBBA RAO B. V. R. CHOWDARI

作者单位: Department of Physics, National University of Singapore, Singapore 117542

会议类型: 国际会议

会议名称: The 12th Asian Conference on Solid State Ionics(第十二届亚洲固态离子学会议暨第十五届中国固态离子学会议)

会议地点: 武汉

会议语种:英文

页码: 820-829

在线出版日期: 2010-05-02（万方平台首次上网日期，不代表论文的发表时间）