18650型柱状锂离子电池的容量衰减机理（英文）

发布时间：2018-05-30 20:19

本文选题：锂离子电池 + 容量衰减　；参考：《Transactions of Nonferrous Metals Society of China》2017年07期

【摘要】：研究18650商业化锂离子全电池在常温条件下的容量衰减机理。结果表明,经过500次循环后,18650柱状电池的容量衰减率为12.91%;对经循环后的电池采用XRD、SEM、EIS和CV进行表征。电化学交流阻抗图谱表明,随着循环的进行,电池的电阻特别是电荷转移电阻逐渐增加;同时,循环伏安测试表明,在循环的后期,电池的锂离子脱嵌可逆性能下降,导致容量衰减。这是因为,在正、负极材料界面处发生电解液与电极材料副反应,反复形成固态电解质界面膜。同时,副反应产物沉积一部分沉积在隔膜上,堵塞隔膜孔,阻碍锂离子的穿梭。因此,锂离子在正负极间的移动阻力增大,导致电池的容量衰减和电位衰减。
[Abstract]:The capacity attenuation mechanism of commercial 18650 lithium ion battery at room temperature was studied. The results showed that after 500 cycles, the capacity attenuation rate of the cell was 12.91, and the battery was characterized by XRDX SEMEIS and CV. The electrochemical impedance diagram showed that the resistance of the battery, especially the charge transfer resistance, increased with the cycle, and the electrochemical voltammetry showed that the reversibility of the lithium ion deintercalation decreased at the later stage of the cycle. Resulting in capacity attenuation. This is because the electrolyte reacts with the electrode material at the interface between the positive and negative electrode materials and forms the solid electrolyte interfacial film repeatedly. At the same time, some of the side reaction products were deposited on the diaphragm, which blocked the pore of the diaphragm and hindered the shuttle of lithium ion. Therefore, the shift resistance of lithium ion between the positive and negative electrodes increases, which leads to the capacity attenuation and potential attenuation of the battery.
【作者单位】：中南大学冶金与环境学院;
【基金】：Project(51574287)supported by the National Natural Science Foundation of China Project(2015CX001)supported by the Innovation-driven Plan in Central South University,China
【分类号】：TM912

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