长寿命高镍锂电池界面重构电解液添加剂研究进展  

Research Progress and Prospect on Electrolyte Additives for Interface Reconstruction of Long-Life Ni-Rich Lithium Batteries

作　　者：韩卓 张丹丰 王海先 郑国瑞 柳明 贺艳兵 Zhuo Han;Danfeng Zhang;Haixian Wang;Guorui Zheng;Ming Liu;Yanbing He(Institute of Materials Research(iMR),Tsinghua Shenzhen International Graduate School,Shenzhen 518055,Guangdong Province,China)

机构地区：[1]清华大学深圳国际研究生院,材料研究院,广东深圳518055

出　　处：《物理化学学报》2024年第9期1-27,共27页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(U2001220)资助项目。

摘　　要：高镍正极匹配锂金属负极是实现高比能锂电池的重要发展方向之一,然而,高比能锂电池体系存在体相结构稳定性差、与表界面难以兼容等共性问题,特别是在高截止电压、宽温域的实际工况条件下,表界面退化往往加速体相结构的破坏,造成电极材料性能快速衰退。相较于离子掺杂和表面包覆等改性手段,基于溶剂-锂盐优化或功能性添加剂主导的电解液诱导界面重构改性工程,可以同时实现对高比能正负极材料电化学循环改性,易于大规模工业生产应用。其中,功能性添加剂能极大提升电极/电解液界面兼容性,同时有利于调控电解液溶剂化结构,利用其电化学氧化/还原活性特征改变高比能电极/电解液电化学界面行为,从而实现高比能锂电池稳定循环。本文论述了不同功能性电解液添加剂在高镍正极和负极表面的成膜性、界面吸附稳定性、界面协同演变、酸水杂质清除等方面改性作用,为筛选和设计特定功能化添加剂实现高比能高镍锂全电池的稳定循环提供了新思路。One of the crucial directions in the pursuit of high-energy-density lithium batteries involves pairing Ni-rich cathodes with lithium metal anodes(LMAs).However,battery systems with high energy density often suffer from issues such as poor phase structure stability and inadequate interface compatibility.These problems are exacerbated under the actual operating conditions with high cut-off voltages and wide temperature ranges.Interface degradation,in such cases,accelerates the destruction of phase structure,leading to rapid performance deterioration of electrode materials.Compared to methods like ion doping and surface coating,an approach centered around electrolyte-induced interface reconstruction modification through solvent-lithium salt optimization or functional additives shows promise.This approach allows for simultaneous electrochemical cyclic modification of both high-energy-density cathode and anode materials,and it can be easily integrated into large-scale industrial production.Ester-based electrolytes,while possessing greater voltage stability compared to ether-based electrolytes,still exhibit side reactions at the interface between high Ni-content cathodes and the electrolyte,as well as between Li metal anodes and the electrolyte.In the absence of effective cathode-electrolyte interface(CEI)and solid-electrolyte interface(SEI)protection,persistent side reactions occur,ultimately leading to electrode failure.To address these challenges and simultaneously enhance electrode/electrolyte interface compatibility while regulating electrolyte solvation structure,functional additives are employed to modify the electrochemical behavior of the high-energy-density battery interface.Traditional ether electrolytes often employ lithium hexafluorophosphate(LiPF_(6))as the primary salt.However,LiPF_(6) suffers from poor thermal stability.Its decomposition or hydrolysis generates hydrogen fluoride(HF),which corrodes the cathode.Moreover,LiPF_(6) decomposition releases phosphorus pentafluoride(PF_(5)),triggering the ring-o

关 键 词：高镍锂电池 电解液添加剂 界面重构 电化学循环改性 低成本 

分 类 号：O646[理学—物理化学]