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

ABSTRACT

A 3D crimped sulfonated polyethersulfone-polyethylene oxide(C-SPES/PEO) nanofiber membrane and long-range lanthanum cobaltate(LaCoO3 ) nanowires are collectively doped into a PEO matrix to acquire a composite solid electrolyte (C-SPES-PEO-LaCoO3 ) 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-LaCoO3 , 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 LaCoO3 nanowires and 3D crimped C-SPES/PEO fibers contribute to Li+ movement. Particularly, the LiFePO4 /C-SPES-PEO-LaCoO3 /Li and NMC811/C-SPES-PEO-LaCoO3 /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 LaCoO3 nanowires are replaced with Gd-doped CeO2 nanowires. The work will provide a novel approach to high performance solid-state electrolytes.