用预循环方法控制富锂锰Li_(1.13)Mn_(0.54)Ni_(0.27)Al_(0.06)O_2的不可逆容量  

Improvement of initial irreversible capacity by pre-cycling for lithium-rich cathode material Li_(1.13)Mn_(0.54)Ni_(0.27)Al_(0.06)O_2

作　　者：吴佳[1,2] 邵威[1,2] 伍小龙[1,2] 王剑华[1,2] 

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093 [2]昆明理工大学分析测试中心,云南昆明650093

出　　处：《电源技术》2017年第3期340-344,共5页Chinese Journal of Power Sources

基　　金：国家自然科学基金项目(51464025)

摘　　要：研究了不同预循环电压对富锂锰正极材料Li_(1.13)Mn_(0.54)Ni_(0.27)Al_(0.06)O_2电化学性能的影响,重点考察了不可逆容量。电化学测试数据表明:采用上截止电压为4.4~4.6 V进行预循环可使初始不可逆容量降低一半;采用阶梯电压预循环制度可有效提高材料电化学性能,初始不可逆比容量从252 mAh/g降低至98 mAh/g,容量保持率达到94.4%,且在10 C倍率下放电比容量依然保持在81 mAh/g;富锂锰正极材料的初始不可逆容量主要来自三个方面:SEI膜的形成、Li_2MnO_3的活化和电解液分解。The lithium-rich cathode material Li1.13Mn0.54Ni0.27Al0.06O2 was synthesized by solid state reaction. The relationship between pre-cycling and the electrochemical performance was studied. Special attention was paid to the high initial irreversible capacity. The studies show that, as the cut-off voltage of pre-cycling has been set between 4.4 V to 4.6 V, the initial irreversible is only 52% of the un-precycled one. Stepwise pre-cycling treatment can effectively reduce the initial irreversible capacity. It can also improve the capacity retention ability and rate properties. The irreversible specific capacity can be reduced from 252 mAh/g to 98 mAh/g after stepwise pre-cycling treatment. The capacity retention rate is 94.4% and the specific capacity is 81 mAh/g at 10 C. The initial irreversible capacity of Li1.13Mn0.54Ni0.27Al0.06O2 is made up of three parts： formation of SEI film,activation of Li2 MnO3 and the decomposition of electrolyte.

关 键 词：富锂锰 不可逆容量 锂电池 

分 类 号：TM912.9[电气工程—电力电子与电力传动]