PVDF-HFP/PAN/PDA@LLZTO Composite Solid Electrolyte Enabling Reinforced Safety and Outstanding Low-Temperature Performance for Quasi-Solid-State Lithium Metal Batteries

Yang Wang; Zhen Chen; Yixin Wu; Yu Li; Ziyu Yue; Minghua Chen

doi:10.1021/acsami.3c02678

PVDF-HFP/PAN/PDA@LLZTO Composite Solid Electrolyte Enabling Reinforced Safety and Outstanding Low-Temperature Performance for Quasi-Solid-State Lithium Metal Batteries

ACS Appl Mater Interfaces. 2023 May 3;15(17):21526-21536. doi: 10.1021/acsami.3c02678. Epub 2023 Apr 18.

Authors

Yang Wang¹, Zhen Chen¹, Yixin Wu¹, Yu Li¹, Ziyu Yue¹, Minghua Chen¹

Affiliation

¹ Key Laboratory of Engineering Dielectric and Applications, Ministry of Education, School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China.

PMID: 37071843
DOI: 10.1021/acsami.3c02678

Abstract

Lithium-ion batteries (LIBs) have achieved a triumph in the market of portable electronic devices since their commercialization in the 1990s due to their high energy density. However, safety issue originating from the flammable, volatile, and toxic organic liquid electrolytes remains a long-standing problem to be solved. Alternatively, composite solid electrolytes (CSEs) have gradually become one of the most promising candidates due to their higher safety and stable electrochemical performance. However, the uniform dispersity of ceramic filler within the polymer matrix remains to be addressed. Generally, all-solid-state lithium metal batteries without any liquid components suffer from poor interfacial contact and low ionic conductivity, which seriously affect the electrochemical performance. Here we report a CSE consisting of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), polydopamine (PDA) coated Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (LLZTO) (denoted as PDA@LLZTO) microfiller, polyacrylonitrile (PAN), and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). Introducing only 4 μL of liquid electrolyte at the electrode|electrolyte interface, the CSE-based cells exhibit high ionic conductivity (0.4 × 10^-3 S cm^-1 at 25 °C), superior cycle stability, and excellent thermal stability. Even under low temperatures, the impressive electrochemical performance (78.8% of capacity retention after 400 cycles at 1 C, 0 °C, and decent capacities delivered even at low temperature of -20 °C) highlights the potential of such quasi-solid-state lithium metal batteries as a viable solution for the next-generation high-performance lithium metal batteries.

Keywords: PDA@LLZTO filler; composite solid electrolyte; lithium metal battery; low-temperature performance; thermal stability.