Open AccessA Stretchable and Safe Polymer Electrolyte with a Protecting‐Layer Strategy for Solid‐State Lithium Metal Batteries
Author(s) -
Zhang Shengzhao,
Liang Taibo,
Wang Donghuang,
Xu Yanjun,
Cui Yongliang,
Li Jingru,
Wang Xiuli,
Xia Xinhui,
Gu Changdong,
Tu Jiangping
Publication year - 2021
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.202003241
Subject(s) - electrolyte , materials science , anode , separator (oil production) , ethylene oxide , chemical engineering , ionic conductivity , polymer , quasi solid , lithium (medication) , trimethyl phosphate , composite material , copolymer , chemistry , electrode , phosphate , dye sensitized solar cell , organic chemistry , medicine , engineering , endocrinology , physics , thermodynamics
An elastic and safe electrolyte is demanded for flexible batteries. Herein, a stretchable solid electrolyte comprised of crosslinked elastic polymer matrix, poly(vinylidene fluoride‐hexafluoropropylene) (PVDF‐HFP), and flameproof triethyl phosphate (TEP) is fabricated, which exhibits ultrahigh elongation of 450%, nonflammability and ionic conductivity above 1 mS cm −1 . In addition, in order to improve the interface compatibility between the electrolyte and Li anode and stabilize the solid‐electrolyte interphase (SEI), a protecting layer containing poly(ethylene oxide) (PEO) is designed to effectively prevent the anode from reacting with TEP and optimize the chemical composition in SEI, leading to a tougher and more stable SEI on the anode. The LiFePO 4 /Li cells employing this double‐layer electrolyte exhibit an 85.0% capacity retention after 300 cycles at 1 C. Moreover, a flexible battery based on this solid electrolyte is fabricated, which can work in stretched, folded, and twisted conditions. This design of a stretchable double‐layer solid electrolyte provides a new concept for safe and flexible solid‐state batteries.