Reactive Polymer as Artificial Solid Electrolyte Interface for Stable Lithium Metal Batteries

• Published in: Angewandte Chemie International Edition Vol. 62; no. 26; pp. e202305287 - n/a
• Main Authors: Naren, Tuoya, Kuang, Gui‐Chao, Jiang, Ruheng, Qing, Piao, Yang, Hao, Lin, Jialin, Chen, Yuejiao, Wei, Weifeng, Ji, Xiaobo, Chen, Libao
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 26-06-2023
• Edition: International ed. in English
• Subjects: Anodes; Carbonate Electrolyte; Carboxylic Acids; Dendrite Suppression; Dendrites; Electrochemical potential; Electrochemistry; Electrode polarization; Electrolytes; Ethers, Cyclic; Lithium; Lithium batteries; Lithium Metal Anode; Lithium-Metal Batteries; Mechanical properties; Metals; Polymer Solid Electrolyte Interphase; Polymers; Solid electrolytes; Carbonate Electrolyte; Lithium Metal Anode; Lithium-Metal Batteries; Polymer Solid Electrolyte Interphase; Dendrite Suppression
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202305287

Lithium (Li) metal anodes have the highest theoretical capacity and lowest electrochemical potential making them ideal for Li metal batteries (LMBs). However, Li dendrite formation on the anode impedes the proper discharge capacity and practical cycle life of LMBs, particularly in carbonate electrolytes. Herein, we developed a reactive alternative polymer named P(St‐MaI) containing carboxylic acid and cyclic ether moieties which would in situ form artificial polymeric solid electrolyte interface (SEI) with Li. This SEI can accommodate volume changes and maintain good interfacial contact. The presence of carboxylic acid and cyclic ether pendant groups greatly contribute to the induction of uniform Li ion deposition. In addition, the presence of benzyl rings makes the polymer have a certain mechanical strength and plays a key role in inhibiting the growth of Li dendrites. As a result, the symmetric Li||Li cell with P(St‐MaI)@Li layer can stably cycle for over 900 h under 1 mA cm−2 without polarization voltage increasing, while their Li||LiFePO4 full batteries maintain high capacity retention of 96 % after 930 cycles at 1C in carbonate electrolytes. The innovative strategy of artificial SEI is broadly applicable in designing new materials to inhibit Li dendrite growth on Li metal anodes.
A reactive surrogate polymer containing carboxylic acid and cyclic ether moieties is developed, that can form an artificial polymeric SEI (APSEI) in situ with lithium metal anodes. This APSEI greatly facilitates the induction of uniform deposition of lithium ions while suppressing the growth of lithium dendrites. The APSEI significantly improved the performance of lithium metal batteries.