Inorganic Chemicals Industry ›› 2025, Vol. 57 ›› Issue (11): 43-51.doi: 10.19964/j.issn.1006-4990.2024-0684

• Research & Development • Previous Articles     Next Articles

Study on enhancement of ionic conductivity in poly(ethylene oxide)-based solid-state electrolytes by boehmite

TIAN Peng(), YANG Guanglong, MU Chenxi, CHEN Junyi, NING Guiling   

  1. School of Chemical Engineering,Dalian University of Technology,Dalian 116023,China
  • Received:2024-12-17 Online:2025-11-10 Published:2025-07-25

Abstract:

Poly(ethylene oxide)(PEO)-based polymer electrolytes exhibit broad application prospects in the field of all-solid-state sodium-ion batteries due to their ability to dissolve various sodium salts and ease of processing.However,PEO has the defects of high crystallinity and insufficient segmental mobility,resulting in low ionic conductivity at room temperature.This study proposed an effective strategy to address this issue.By incorporating succinonitrile(SN) and boehmite(BM) into the polymer system of PEO and sodium bis(trifluoromethanesulfonyl)imide(NaTFSI).A composite solid electrolyte(PEO-NaTFSI-SN-BM) with excellent performance was successfully prepared.The mechanism of SN and BM improving the ionic conductivity of solid-state electrolyte was analyzed by using techniques including X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS) and scanning electron microscopy(SEM).The experimental results demonstrated that,when only SN was added and the molar ratio of SN to EO was 1∶8,a self-supporting membrane(PNS8) could be formed,significantly increasing the ionic conductivity of the PEO-NaTFSI polymer electrolyte from the initial 2.27×10-6 S/cm to 4.51×10-5 S/cm at 30 ℃.Upon further incorporation of BM,the ionic conductivity of the composite solid electrolyte was increased to 6.99×10-5 S/cm,while simultaneously enhancing the mechanical properties of the electrolyte membrane.In the presence of BM,when the molar ratio of SN to EO was further increased to 1∶4,a self-supporting membrane(PNS4B10) could still be formed.The ionic conductivity of PNS4B10 at 30 ℃ reached as high as 1.43×10-4 S/cm,representing an approximately 60-fold improvement compared to the initial PEO-NaTFSI polymer electrolyte.The introduction of BM not only facilitated ion transport of the solid-state electrolyte,but also enhanced its mechanical properties,thereby enabling higher SN loading and further optimization of ionic conductivity.This composite solid electrolyte represented a promising approach for achieving high ionic conductivity in all-solid-state sodium metal batteries at room temperature.

Key words: boehmite, poly(ethylene oxide), succinonitrile, ionic conductivity, sodium solid state electrolyte

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