Beneficial impact of lithium bis(oxalato)borate as electrolyte additive for high-voltage nickel-rich lithium-battery cathodes  

作　　者：Fanglin Wu Angelo Mullaliu Thomas Diemant Dominik Stepien Tatjana NParac-Vogt Jae-Kwang Kim Dominic Bresser Guk-Tae Kim Stefano Passerini 

机构地区：[1]Helmholtz Institute Ulm(HIU),Ulm,Germany [2]Karlsruhe Institute of Technology(KIT),Karlsruhe,Germany [3]Department of Chemistry,KU Leuven,Leuven,Belgium [4]Department of Energy Convergence Engineering,Cheongju University,Cheongju,Republic of Korea [5]Chemistry Department,Sapienza University of Rome,Rome,Italy

出　　处：《InfoMat》2023年第8期67-80,共14页信息材料（英文）

基　　金：the financial support from the Chinese Scholarship Council(CSC).Moreover,the authors would like to acknowledge the financial support from the Helmholtz Association and the European Commission in the frame of the SiGNE project(875557);Jae-Kwang Kim acknowledges the support from the Advancement of Technology(KIAT)and the National Research Foundation of Korea(NRF)grant funded by the Korea Government(P0011933 and 2021R1A4A2001687).

摘　　要：High-voltage nickel-rich layered cathodes possess the requisite,such as excellent discharge capacity and high energy density,to realize lithium batteries with higher energy density.However,such materials suffer from structural and interfacial instability at high voltages(>4.3 V).To reinforce the stability of these cathode materials at elevated voltages,lithium borate salts are investigated as electrolyte additives to generate a superior cathode-electrolyte interphase.Specifically,the use of lithium bis(oxalato)borate(LiBOB)leads to an enhanced cycling stability with a capacity retention of 81.7%.Importantly,almost no voltage hysteresis is detected after 200 cycles at 1C.This outstanding electrochemical performance is attributed to an enhanced structural and interfacial stability,which is attained by suppressing the generation of micro-cracks and the superficial structural degradation upon cycling.The improved stability stems from the formation of a fortified borate-containing interphase which protects the highly reactive cathode from parasitic reactions with the electrolyte.Finally,the decomposition process of LiBOB and the possible adsorption routes to the cathode surface are deduced and elucidated.

关 键 词：cathode electrolyte interphase electrolyte additive high voltage cathodes LIBOB nickel-rich cathodes 

分 类 号：TM912[电气工程—电力电子与电力传动]