Accelerating lithium ion transport via increasing the entropy of the electrolyte for stable lithium metal batteries  

作　　者：Chuan Wang Tenglong Ouyang Xinxiang Wang Sheng Liu Guilei Tian Fengxia Fan Pengfei Liu Shuhan Wang Chenrui Zeng Chaozhu Shu 

机构地区：[1]College of Materials and Chemistry&Chemical Engineering,Chengdu University of Technology,Chengdu 610059,Sichuan,China

出　　处：《Journal of Energy Chemistry》2024年第12期384-392,共9页能源化学（英文版）

基　　金：supported by the National Natural Science Foundation of China (21905033, 52271201);the Science and Technology Department of Sichuan Province (2022YFG0100,2022ZYD0045)。

摘　　要：Promoting inorganic-rich solid-electrolyte interphase (SEI) formation by constructing anion-rich solvated structures is a promising strategy for improving the long-term cycling of lithium-metal batteries.However,the increase of anions within the solvated structure inevitably reduces the coordination of Li^(+) with the solvent,which leads to a low lithium diffusion coefficient and a decreased lithium conductivity.Here,high entropy electrolyte is achieved by increasing the molecular diversity in electrolyte.Multiple anions (TFSI^(-),FSI^(-),NO_(3)^(-) and PF_(6)^(-)) presented in entropy electrolyte individually coordinate with Li^(+),creating a diverse and anion-rich solvation structure.The large variety of solvation structures leads to a diversified Li^(+) diffusion barriers in the electrolyte,which results in the increase of channels available for Li^(+) diffusion.Thus,three-dimensional diffusion with high Li^(+) diffusion coefficient occurs in HE electrolytes.Furthermore,the anion-rich solvation structures promote the formation of the inorganic-rich SEI.As a result,over 2000 h of reversible Li plating/stripping with a low overpotential less than 27 mV is achieved in Li||Li cell using electrolyte modified by high-entropy strategy.Besides,the Li||LFP full cell with a negative capacity/positive capacity (N/P) ratio of 4.52 exhibits remarkably enhanced cycling stability,retaining 83.6% of its initial capacity after 150 cycles.This strategy offers a novel approach for accelerating Li^(+) transport kinetics and constructing stable SEI in lithium metal batteries.

关 键 词：Lithium metal batteries electrolyte ENTROPY Lithium ion diffusion Inorganic-rich SEI 

分 类 号：O646[理学—物理化学] TM912[理学—化学]