Molecular Engineering of Weakly Solvating Dinitrile Electrolytes for Long‐Lasting Room‐Temperature Lithium Metal Batteries
Abstract
Abstract The development of lithium metal batteries (LMBs) relies on advanced solid‐state electrolytes. Solid‐state polymer electrolytes (SPEs) offer advantages such as cost‐effectiveness, mechanical flexibility, and light weight; however, their practical use is hindered by limited ionic conductivity, narrow electrochemical stability window, and suboptimal cycling performance. Herein, we present a class of weakly‐solvating dinitrile‐based SPEs (DBSPEs) composed of a poly(2‐(2‐(2‐methoxyethoxy)ethoxy)ethyl acrylate) network coupled with structurally modulated dinitrile solvents. Through rationale molecular engineering, the synergistic combination of short ethylene oxide side chains and weakly coordinating dinitrile solvents enables weak hybrid solvation of lithium ions, thereby facilitating rapid ion migration and uniform lithium deposition. The optimized DBSPE‐2 exhibits a high ionic conductivity (∼2.2 × 10 −3 S cm −1 ) and an extremely wide electrochemical window (∼5.7 V). Notably, the Li||DBSPE‐2||Li symmetric cell yields stable lithium plating/stripping over 6900 h at 0.1 mA cm⁻ 2 under ambient conditions (26 °C). When paired with LiFePO₄ in a full cell, the LMBs deliver a superior fast‐charging capability, realizing 80.78% capacity retention after 1500 cycles at 2.0 C rate. This work provides fundamental insights into the solvation structure and accordingly realizes long‐lasting LMBs with weak solvents.
Article Details
Authors (12)
Chuan Luo
Chunpeng Ning
State Key Lab of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials South China Advanced Institute for Soft Matter Science and Technology School of Emergent Soft Matter South China University of Technology Guangzhou 510640 China
Xuehai Huang
South China Advanced Institute for Soft Matter Science and Technology, School of Emergent Soft Matter
Panjing Zhang
State Key Lab of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials South China Advanced Institute for Soft Matter Science and Technology School of Emergent Soft Matter South China University of Technology Guangzhou 510640 China
Liwei Yang
Sijing Wang
Junchen Wang
School of Chemical Engineering and Technology
Yu Wang
Kai Wan
Guangdong Provincial Key Laboratory of Fuel Cell Technology School of Chemistry and Chemical Engineering South China University of Technology Guangzhou People's Republic of China
Zi‐Hao Guo
State Key Lab of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, South China Advanced Institute for Soft Matter Science and Technology, School of Emergent Soft Matter South China University of Technology Guangzhou 510640 P.R. China
Kan Yue
Zhenxing Liang
School of Chemistry and Chemical Engineering South China University of Technology Guangzhou Guangdong Province China