Improved cyclic stability of LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2) cathode enabled by a novel CEI forming additive  

作　　者：Zulipiya SHADIKE Yiming CHEN Lin LIU Xinyin CAI Shuiyun SHEN Junliang ZHANG 

机构地区：[1]Institute of Fuel Cells,School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Frontiers in Energy》2024年第4期535-544,共10页能源前沿（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.22209106).

摘　　要：The undesired side reactions at electrode/electrolyte interface as well as the irreversible phase evolution during electrochemical cycling significantly affect the cyclic performances of nickel-rich NMCs electrode materials.Electrolyte optimization is an effective approach to suppress such an adverse side reaction,thereby enhancing the electrochemical properties.Herein,a novel boron-based film forming additive,tris(2,2,2-trifluoroethyl)borate(TTFEB),has been introduced to regulate the interphasial chemistry of LiNi0.8Mn0.1Co0.1O2(NMC811)cathode to improve its long-term cyclability and rate properties.The results of multi-model diagnostic study reveal that formation lithium fluoride(LiF)-rich and boron(B)containing cathode electrolyte interphase(CEI)not only stabilizes cathode surface,but also prevents electrolyte decomposition.Moreover,homogenously distributed B containing species serves as a skeleton to form more uniform and denser CEI,reducing the interphasial resistance.Remarkably,the Li/NMC811 cell with the TTFEB additive delivers an exceptional cycling stability with a high-capacity retention of 72.8%after 350 electrochemical cycles at a 1 C current rate,which is significantly higher than that of the cell cycled in the conventional electrolyte(59.7%).These findings provide a feasible pathway for improving the electrochemical performance of Ni-rich NMCs cathode by regulating the interphasial chemistry.

关 键 词：NMC811 cathode electrolyte interphase film forming additives cyclic stability 

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]