Well-Dispersed Polydopamine In Situ Coated Lithium Montmorillonite Nanofillers Composite Polyethylene Oxide-Based Solid Electrolyte for All-Solid-State Lithium Batteries

In lithium batteries, composite solid electrolytes gain their reputation owing to their great safety, excellent mechanical properties, and remarkably improved electrochemical performance. Herein, composite polyethylene oxide (PEO)-based solid electrolytes with well-dispersed in situ polydopamine-coated lithium montmorillonite (PDA@LiMMT) nanofillers are successfully fabricated. The involvement of PDA@LiMMT retards significantly the crystallization of PEO, addressing a manifest enhancement in the ionic conductivity of the modified composite solid electrolyte. A conducive ionic conductivity value of 3.06 x 10-4 S cm-1 at 60 degrees C is reached, while the electrochemical window widens to 4.7 V. The assembled Li/solid polymer electrolytes/LiFePO4 battery exhibits a 158.2 mA h g-1 high discharge specific capacity at a current density of 0.5C; besides, the capacity retention rate keeps 86% after 200 cycles. The enhancement of the cycle stability of the solid-state batteries highlights the excellent interfacial stability between the modified solid electrolytes and the lithium electrode, which originates from lithiophilicity of PDA. Polyethylene oxide/polydopamine (PDA)-coated lithium montmorillonite composite electrolytes are obtained. The lithophilicity of PDA with Li electrode favors the enhancement of the cycle stability of the solid-state batteries. The assembled LiFePO4 battery exhibits a 158.2 mA h g-1 high discharge specific capacity at a current density of 0.5C; besides, the capacity retention rate keeps 86% after 200 cycles.image (c) 2023 WILEY-VCH GmbH