Revealing ionically isolated Li loss in practical rechargeable Li metal pouch cells  

揭示锂金属软包电池中的离子绝缘锂损失

作　　者：Xiangrui Duan Yuanjian Li Kai Huang Shuibin Tu Guocheng Li Wenyu Wang Hongyu Luo Zihe Chen Chunhao Li Kai Cheng Xin-Xin Wang Li Wang Yongming Sun 段祥瑞;李元建;黄锴;涂水彬;李国成;王文宇;罗宏宇;陈子和;李春浩;程凯;王鑫鑫;王莉;孙永明

机构地区：[1]Wuhan National Laboratory for Optoelectronics,Huazhong University of Science and Technology,Wuhan 430074,China [2]State Key Laboratory of Material Processing and Die&Mold Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China [3]State Key Laboratory of Material Processing and Die&Mold Technology,Department of Mechanics,School of Aerospace Engineering,Huazhong University of Science and Technology,Wuhan 430074,China [4]Institute of Nuclear&New Energy Technology,Tsinghua University,Beijing 100084,China

出　　处：《Science Bulletin》2025年第6期914-922,共9页科学通报(英文版)

基　　金：financially supported by the Natural Science Foundation of China(52272207).

摘　　要：The degradation of rechargeable lithium(Li)metal batteries is primarily attributed to active Li loss,encompassing isolated Li,also known as“dead Li”,and solid electrolyte interphase(SEI-Li).Comprehending the formation of dead Li is pivotal for devising strategies to mitigate Li loss.Herein,we reveal the existence of an alternative form of dead Li,termed ionically isolated Li(I-iLi),which diverges from the traditionally recognized electronically isolated Li(E-iLi).This phenomenon is elucidated through a quantitative analysis of electrolyte-dependent capacity recovery at a specific state of health(SOH)in high-energy pouch cells,which originates from disconnections within the Li-ion percolation network induced by electrolyte de-wetting.Furthermore,we propose the electrolyte infilling ratio(EFR),contingent upon the porosity of Li deposits and electrolyte retention,as a criterion to evaluate electrode wettability.To uphold a high EFR environment,we introduce stress modulation to compact the anode structure and mitigate electrolyte degradation,significantly reducing the I-iLi content from 21%at 0.1 MPa to 1%at 1 MPa.Harnessing these insights,a prototype anode-free LiNi_(0.95)Mn_(0.03)Co_(0.02)O_(2)||Cu pouch cell(1.4 Ah)achieves an extraordinary cell-level energy density of 551 Wh kg^(−1)and maintains 70%capacity after 100 cycles at 0.2 C.

关 键 词：Dead Li Ionically isolated Li Electrolyte infilling ratio Li metal batteries Lean electrolyte conditions 

分 类 号：TM912[电气工程—电力电子与电力传动]