过放电对MCMB-LiCoO2电池性能的影响

通过对MCMB为负极、LiCoO2为正极、金属锂为参比电极的AA型三电极锂离子电池的性能测试及正负极对锂参比电极的电位测试,并结合X R D和SEM实验,研究了过放电对MCMB-LiCoO2锂离子电池性能的影响。结果表明:当M CMB-LiCoO2电池过放至0.0伏时,负极MCMB表面上的SEI膜被损坏,集流体铜箔的腐蚀溶解较严重,再次形成的SEI膜的性能可能较差,这使负极阻抗增大,极化增强,相应地使电池在过放电以后的循环过程中的放电容量、放电电压和充放电效率大为降低。但过放电对MCMB的结构和正极性能没有影响。

Effects of over-discharge on performance of MCMB-LiCoO2 lithium-ion battery

The AA size three-electrode lithium-ion batteries,using LiCoO2 as cathode and MCMB as anode and lithium metal as reference electrode,were assembled.The effects of overdischarge on performance of MCMB-LiCoO2 lithium-ion batteries were investigated by combining performance measurements and the potential measurements of cathode and anode vs.lithium reference electrode with XRD and SEM experiments.The results showed that,when MCMB-LiCoO2 lithium-ion batteries were overdischarged to 0.0V,the SEI of MCMB was destroyed,corrosion of copper foil was very severe and the performance of secondary formative SEI was very bad,which resulted in aggrandizement of anode's impedance and augmentation of anode's polarization.Accordingly,after overdischarge,the discharge capacity, discharge voltage and charge/discharge efficiency of the battery fell greatly.But overdischarge had no influence on the structure of MCMB and performance of cathode.