过充电对 MCMB-LiCoO2电池性能的影响

组装了以中间相炭微球（MCMB）为负极、LiCoO2为正极、金属锂为参比电极的从型三电极锂离子蓄电池，通过对三电极电池在过充电时、过充电前后的性能测试，及正负极对锂参比电极的电位测试，并结合XRD和SEM实验，研究了过充电对MCMB-LiCoO2锂离子蓄电池的性能影响。结果表明：当电池过充电至4，8V时，电池表现出较高的充放电容量，但容量衰减较快，循环稳定性较差，且电池在放电初期时的放电曲线呈凸弧形。过充电导致的正极材料LiCoO2相结构的变化、正负电极表面钝化膜的增长变厚，以及正极集流体铝箔的氧化腐蚀，是电池性能迅速恶化的主要原因。

Effects of overcharge on performance of MCMB- LiCoO2 battery

The AA size three-electrode lithium-ion batteries, using LiCoO2 as cathode electrode and MCMB as anode electrode and lithium metal as reference electrode, were assembled. The effects of overcharge on performances of MCMB-LiCoO2 lithium-ion batteries were investigated by combing performance measurements and the potential measurements of cathode electrode and anode electrode vs. lithium reference electrode with XRD and SEM experiment. The results showed that, when MCMB-LiCoO2 lithium-ion batteries were overcharged to 4.8V, the batteries had higher charge/discharge capacity, but its capacity fade was faster and cycling stability was worse, and its discharge curve emerged arched curve in the initial stage of discharge. The phase transition of LiCoO2, the passivated-film thickening on cathode material face and anode electrode face, and oxidative corrosion of aluminum foil due to overcharge, were main reasons of battery's performance rapid deterioration.