Synthesis and electrochemical properties of non-stoichiometric Li-Mn-spinel (Li_1.02M_xMn_1.95O_{4?span style='font-style: italic'>y}F_y) for lithium ion battery application

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• 作者：Chuanqi Feng^a ; Hua Li^a ; Chaofeng Zhang^c ; Zaiping Guo^b ; ^c ; ^{zguo@uow.edu.au} ; Huimin Wu^a ; Jing Tang^a
• 关键词：Lithium-ion batteries ; Li&ndash ; Mn-Spinel ; Electrochemical properties ; Chemical synthesis
• 刊名：Electrochimica Acta
• 出版年：2012
• 出版时间：1 February, 2012
• 年：2012
• 卷：61
• 期：Complete
• 页码：87-93
• 全文大小：1207 K

文摘

Non-stoichiometric spinel compounds Li_1.02M_xMn_1.95O_4?em>yF_y (M = Co, Y, and Ga) were prepared for the first time by the rheological phase reaction method. The Li_1.02M_xMn_1.95O_4?em>yF_y samples were characterized by X-ray diffraction, while the particle size and shape of the Li_1.02M_xMn_1.95O_4?em>yF_y were observed by scanning and transmission electron microscopy. The as-prepared samples were used as cathode materials in lithium-ion batteries, their electrochemical properties were tested, and the results showed that the non-stoichiometric spinels Li_1.02M_xMn_1.95O_4?em>yF_y had better cycling performance than pure LiMn₂O₄. In addition, among the different non-stoichiometric spinel samples, the Li_1.02Mn_1.95Co_0.02Y_0.01Ga_0.01O_3.97F_0.03 sample not only had higher charge/discharge capacity, but also showed the best cycling performance, as the loss of its capacity was only 7 % after 100 cycles. The possible reasons for the outstanding electrical properties of Li_1.02Mn_1.95Co_0.02Y_0.01Ga_0.01O_3.97F_0.03 are also discussed.