Organoboron- and Cyano-Grafted Solid Polymer Electrolytes Boost the Cyclability and Safety of High-Voltage Lithium Metal Batteries

Dong Liu; Zheng Lu; Zehua Lin; Chunxiao Zhang; Kuan Dai; Weifeng Wei

doi:10.1021/acsami.3c01681

Organoboron- and Cyano-Grafted Solid Polymer Electrolytes Boost the Cyclability and Safety of High-Voltage Lithium Metal Batteries

ACS Appl Mater Interfaces. 2023 May 3;15(17):21112-21122. doi: 10.1021/acsami.3c01681. Epub 2023 Apr 20.

Authors

Dong Liu¹, Zheng Lu¹, Zehua Lin¹, Chunxiao Zhang¹, Kuan Dai², Weifeng Wei¹

Affiliations

¹ State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083, P. R. China.
² College of Materials and Chemical Engineering, Hunan Institute of Engineering, Xiangtan 411104, P. R. China.

PMID: 37078862
DOI: 10.1021/acsami.3c01681

Abstract

Solid-state polymer electrolytes (SPEs) are deemed as a class of sought-after candidates for high-safety and high-energy-density solid-state lithium metal batteries, but their low ionic conductivity, narrow electrochemical windows, and severe interfacial deterioration limit their practical implementations. Herein, an organoboron- and cyano-grafted polymer electrolyte (PVNB) was designed using vinylene carbonate as the polymer backbone and organoboron-modified poly(ethylene glycol) methacrylate and acrylonitrile as the grafted phases, which may facilitate Li-ion transport, immobilize the anions, and enlarge the oxidation voltage window; therefore, the well-tailored PVNB exhibits a high Li-ion transference number (t_Li⁺ = 0.86), a wide electrochemical window (>5 V), and a high ionic conductivity (σ = 9.24 × 10^-4 S cm^-1) at room temperature (RT). As a result, the electrochemical cyclability and safety of the Li|LiFePO₄ and Li|LiNi_0.8Co_0.1Mn_0.1O₂ cells with in situ polymerization of PVNB are substantially improved by forming the stable organic-inorganic composite cathode electrolyte interphase (CEI) and the Li₃N-LiF-rich solid electrolyte interphase (SEI).

Keywords: cathode electrolyte interphase; high-voltage lithium metal batteries; in situ polymerization; solid electrolyte interphase; solid-state polymer electrolytes.