LiPF6 and lithium difluoro(oxalato)borate/ethylene carbonate+dimethyl carbonate+ethyl(methyl)carbonate electrolyte for LiNi0.5Mn1.5O4 cathode  

作　　者：ZHOU Hong-ming GENG Wen-jun LI Jian 周宏明;耿文俊;李荐

机构地区：[1]School of Materials Science and Engineering,Central South University,Changsha 410083,China [2]Hunan Province Zhengyuan Energy Storage Materials and Devices Research,Changsha 410083,China

出　　处：《Journal of Central South University》2017年第5期1013-1018,共6页中南大学学报（英文版）

基　　金：Project(K1403375-11)supported by Science and Technology Planning Project of Changsha,China

摘　　要：LiODFB electrolyte’s compatibility with LiNi0.5Mn1.5O4high-voltage cathode material was studied by cyclic voltammetry, charge-discharge test and AC impedance. The results show that at 25 and 60 °C, the LiODFB-based electrolyte has better electrochemical stability than LiPF6. AC impedance plots show that the LiODFB battery has a lower charge-transfer resistance than LiPF6battery at 60 °C, which indicates that LiODFB battery has excellent cycling performance at high temperature. At 25 and 60 °C, the LiNi0.5Mn1.5O4/Li half cells with LiODFB or LiPF6as electrolyte all have simple redox peak, showing that each of them has an excellent reversibility. LiODFB battery has better cycle performance than LiPF6battery at 25 °C and 60 °C. At 25 °C, their 0.5C initial discharge specific capacities are 126.3 and 131.6 mA·h/g, and their capacity retention ratios of the 100th cycle are 97.1% and 94.7%, respectively. At 60 °C, their 0.5C initial discharge specific capacities are 132.6 and 129.1 mA·h/g, and their capacity retention ratios of the 100th cycle are 94.1% and 81.7%, respectively. © 2017, Central South University Press and Springer-Verlag GmbH Germany.LiODFB electrolyte's compatibility with LiNi_(0.5)Mn_(1.5)O_4 high-voltage cathode material was studied by cyclic voltammetry, charge-discharge test and AC impedance. The results show that at 25 and 60 °C, the LiODFB-based electrolyte has better electrochemical stability than LiPF_6. AC impedance plots show that the LiODFB battery has a lower charge-transfer resistance than LiPF_6 battery at 60 °C, which indicates that LiODFB battery has excellent cycling performance at high temperature. At 25 and 60 °C, the LiNi_(0.5)Mn_(1.5)O_4/Li half cells with Li ODFB or LiPF_6 as electrolyte all have simple redox peak, showing that each of them has an excellent reversibility. LiODFB battery has better cycle performance than LiPF_6 battery at 25 °C and 60 °C. At 25 °C, their 0.5C initial discharge specific capacities are 126.3 and 131.6 m A·h/g, and their capacity retention ratios of the 100 th cycle are 97.1% and 94.7%, respectively. At 60 °C, their 0.5C initial discharge specific capacities are 132.6 and 129.1 m A·h/g, and their capacity retention ratios of the 100 th cycle are 94.1% and 81.7%, respectively.

关 键 词：CARBONATION Cathodes Charge transfer Cyclic voltammetry Electric batteries Electric discharges Electric impedance Electrodes Electrolytes Lithium compounds Manganese 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ131.11[化学工程—无机化工]