Hot-Pressing Enhances Mechanical Strength of PEO Solid Polymer Electrolyte for All-Solid-State Sodium Metal Batteries

Lanqing Zhao; Minjie Hou; Kun Ren; Dongrong Yang; Fupeng Li; Xiecheng Yang; Yingjie Zhou; Da Zhang; Shan Liu; Yong Lei; Feng Liang

doi:10.1002/smtd.202301579

Hot-Pressing Enhances Mechanical Strength of PEO Solid Polymer Electrolyte for All-Solid-State Sodium Metal Batteries

Small Methods. 2024 Mar 3:e2301579. doi: 10.1002/smtd.202301579. Online ahead of print.

Authors

Lanqing Zhao¹, Minjie Hou¹, Kun Ren¹, Dongrong Yang¹, Fupeng Li¹, Xiecheng Yang¹, Yingjie Zhou¹, Da Zhang^{1

2

3}, Shan Liu⁴, Yong Lei⁵, Feng Liang^{1

2

3}

Affiliations

¹ Key Laboratory for Nonferrous Vacuum Metallurgy of Yunnan Province, Kunming University of Science and Technology, Kunming, 650093, China.
² National Engineering Research Center of Vacuum Metallurgy, Kunming University of Science and Technology, Kunming, 650093, China.
³ Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, China.
⁴ School of Chemical Engineering, North China University of Science and Technology, Tangshan, 063009, China.
⁵ Fachgebiet Angewandte Nanophysik, InstitutfürPhysik & IMNMacroNano, Technische Universität Ilmenau, 98693, Ilmenau, Germany.

PMID: 38433396
DOI: 10.1002/smtd.202301579

Abstract

Poly(ethylene oxide) (PEO)-based solid polymer electrolytes (SPEs) are widely utilized in all-solid-state sodium metal batteries (ASSSMBs) due to their excellent flexibility and safety. However, poor ionic conductivity and mechanical strength limit its development. In this work, an emerging solvent-free hot-pressing method is used to prepare mechanically robust PEO-based SPE, while sodium superionic conductors Na₃ Zr₂ Si₂ PO₁₂ (NZSP) and NaClO₄ are introduced to improve ionic conductivity. The as-prepared electrolyte exhibits a high ionic conductivity of 4.42 × 10^-4 S cm^-1 and a suitable electrochemical stability window (4.5 V vs Na/Na⁺ ). Furthermore, the SPE enables intimate contact with the electrode. The Na||Na₃ V₂ (PO₄ )₃ @C ASSSMB delivers a high-capacity retention of 97.1% after 100 cycles at 0.5 C and 60 °C, and exhibits excellent Coulombic efficiency (CE) (close to 100%). The ASSSMB with the 20 µm thick electrolyte also demonstrates excellent cyclic stability. This study provides a promising strategy for designing stable polymer-ceramic composite electrolyte membranes through hot-pressing to realize high-energy-density sodium metal batteries.

Keywords: capacity retention; hot-pressing; poly(ethylene oxide); sodium metal batteries; solid polymer electrolytes.

Abstract

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