Composite Solid Electrolyte with Continuous and Fast Organic–Inorganic Ion Transport Highways Created by 3D Crimped Nanofibers@functional Ceramic Nanowires

Abstract

Abstract A 3D crimped sulfonated polyethersulfone‐polyethylene oxide(C‐SPES/PEO) nanofiber membrane and long‐range lanthanum cobaltate(LaCoO 3 ) nanowires are collectively doped into a PEO matrix to acquire a composite solid electrolyte (C‐SPES‐PEO‐LaCoO 3 ) for all‐solid‐state lithium metal batteries(ASSLMBs). The 3D crimped structure enables the fiber membrane to have a large porosity of 90%. Therefore, under the premise of strongly guaranteeing the mechanical properties of C‐SPES‐PEO‐LaCoO 3 , the ceramic nanowires conveniently penetrated into the 3D crimped SPES nanofiber without being blocked, which can facilitate fast ionic conductivity by forming 3D continuous organic–inorganic ion transport pathways. The as‐prepared electrolyte delivers an excellent ionic conductivity of 2.5 × 10 −4 S cm −1 at 30 °C. Density functional theory calculations indicate that the LaCoO 3 nanowires and 3D crimped C‐SPES/PEO fibers contribute to Li + movement. Particularly, the LiFePO 4 /C‐SPES‐PEO‐LaCoO 3 /Li and NMC811/C‐SPES‐PEO‐LaCoO 3 /Li pouch cell have a high initial discharge specific capacity of 156.8 mAh g −1 and a maximum value of 176.7 mAh g −1 , respectively. In addition, the universality of the penetration of C‐SPES/PEO nanofibers to functional ceramic nanowires is also reflected by the stable cycling performance of ASSLMBs based on the electrolytes, in which the LaCoO 3 nanowires are replaced with Gd‐doped CeO 2 nanowires. The work will provide a novel approach to high performance solid‐state electrolytes.

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