Capacity fade of Li-ion cells cycled at different temperatures
Capacity fade of Li-ion cells cycled at different temperatures
复制标题
不同温度下循环锂离子电池的容量衰减
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
B. Popov
中科院分区：
文献类型：
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作者：
B. Haran;P. Ramadass;R. White;B. Popov
Cycling characteristics of Sony 18650 cells with LiCoO/sub 2/ as the positive electrode material have been studied at different temperatures with DC charging protocol. The capacity fade of lithium ion cells was found to increase with increase in temperature. Cells cycled at RT and 45/spl deg/C showed a capacity fade of 30% and 36% respectively after 800 cycles, while the cell cycled at 55/spl deg/C failed to continue beyond 500 cycles. The rate capability of the cells continues to decrease with cycling. This can be attributed to increased resistance at both electrodes. Impedance measurements for both full and half-cells show an overall increase in the cell resistance with cycling and temperature. Charge-discharge studies on individual pellet electrodes show a reduced tendency for lithiation for both LiCoO/sub 2/ and carbon. XRD studies of the positive electrode up to 300 cycles shows a decrease in the lithium stoichiometry with cycling and temperature. Capacity fade in Sony 18650 cells is attributed to oxidation of cathode (LiCoO/sub 2/). Both primary (Li/sup +/) and secondary active material (LiCoO/sub 2//C) is lost during cycling.
