Crosslinked Polymer‐Brush Electrolytes: An Approach to Safe All‐Solid‐State Lithium Metal Batteries at Room Temperature

Abstract

Electric vehicles, intelligent machines, and portable electronics in our daily lives are placing insatiable demand on safe and powerful battery materials that can function at room temperature. Herein, we report an ultrathin and robust solid-state electrolyte with crosslinked polymer-brush architecture. On one hand, the highly mobile polymer brushes with a moderate side chain length enable efficient cation solvation and fast ion transport, offering room-temperature ionic conductivity as high as 0.23 mS cm À 1 . On the other hand, incorporation of the inorganic core crosslinker endows the material with enhanced mechanical strength, thermal stability, and fire resistance. As a result, the crosslinked polymer-brush electrolyte films demonstrate stable lithium electrodeposition and great electrochemical performance in Li/LiFePO 4 cells at 30 °C, providing a promising pathway to next-generation safe and high-energy lithium metal batteries.

Unveiling the Side-Chain Effect on Ionic Conductivity of Poly(ethylene oxide)-Based Polymer-Brush Electrolytes

“…10 10 s –1 ), resulting in unqualified ionic conductivity for practical battery applications. To further improve the ionic conductivity of PEO-based SPEs, various molecular engineering strategies are proposed, including grafting brush polymers, − , block copolymers, − cross-linking polymers, − nanoparticle incorporation, − and others. , …”

Solid hybrid electrolytes based on conductive oxides and polymer electrolytes for all-solid-lithium batteries

“…The design and synthesis of novel polymer matrices have shown to be effective for improving the performance of SHEs. Various approaches have been explored to enhance the ionic conductivity of polymer electrolytes, including the use of hyperbranching, [188][189][190][191] brushing, [192][193][194][195] star-shape, [196][197][198][199][200] comb-like, [201][202][203][204] cross-linked structures, [205][206][207][208][209][210][211] blending, [212][213][214] plasticizers, 215,216 and polymers in salts. Yamamoto's group conducted research on hyperbranched poly(bistriethylene glycol benzoate) (Fig.…”

Thermal‐Stable Separators: Design Principles and Strategies Towards Safe Lithium‐Ion Battery Operations

“…It was indicated that the SPE had no melting point and was entirely amorphous, which was advantageous for improving ionic conductivity. The SPE demonstrated a high ionic conductivity of 2.35×10 −4 S cm −1 at room temperature with no short circuit for a period of 2000 h, and a broad electrochemical window of about 4.63 V. Ji et al [107] . designed a brush‐like cross‐linked polymer separator with strong dendrite resistance and thermal stability of inorganic particles.…”