Sandwich structured PVDF-HFP-based composite solid electrolytes for solid-state lithium metal batteries

• Published in: Ionics Vol. 28; no. 7; pp. 3243 - 3253
• Main Authors: Xu, Kang, Xu, Chao, Jiang, Yujie, Cai, Jinhai, Ni, Jiaxi, Lai, Chunyan
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2022; Springer Nature B.V
• Subjects: Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Electrochemistry; Energy Storage; Ion currents; Lithium batteries; Lithium ions; Molten salt electrolytes; Optical and Electronic Materials; Original Paper; Polyacrylonitrile; Polyvinylidene fluorides; Product safety; Renewable and Green Energy; Solid electrolytes; Tensile strength; Lithium dendrite; Solid-state lithium metal battery; Composite solid electrolyte; Sandwich structure
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-022-04599-z

It is crucial to develop solid electrolyte with good mechanical and electrochemical stability for the application of lithium metal battery. In this work, a sandwich-structured composite solid electrolyte is designed and prepared based on the blend of polyvinylidene fluoride-hexafluoropropylene/polyacrylonitrile (PVDF-HFP/PAN) polymer, Li 6.46 La 3 Zr 1.46 Ta 0.54 O 12 as filler, and a layer of PE film is introduced in the middle to act as a skeleton. The sandwich-structured PVDF-HFP/PAN-10%LLZTO-PE composite solid electrolyte displays a tensile strength of 66.58 MPa, high ionic conductivity of 2.28 × 10 -4 S/m at 25 °C, wide electrochemical stable window of 4.8 V, and high lithium ion transfer number of 0.44. The LiFePO 4 | PVDF-HFP/PAN-10%LLZTO-PE | Li coin battery shows a high specific capacity of 161.9 mAh/g and retains 150.2 mAh/g after 300 cycles at 1 C. Furthermore, the LiFePO 4 | PVDF-HFP/PAN-10%LLZTO-PE | Li pouch battery shows excellent safety and functionality.