Halloysite nanotubes modified poly(vinylidenefluoride-co-hexafluoropropylene)-based polymer-in-salt electrolyte to achieve high-performance Li metal batteries

Linghao Zhang; Xin Xu; Sen Jiang; Lai Wei; Kang Xi; Yue Lei; Xiang Cheng; Junying Yin; Yunfang Gao

doi:10.1016/j.jcis.2023.04.127

Halloysite nanotubes modified poly(vinylidenefluoride-co-hexafluoropropylene)-based polymer-in-salt electrolyte to achieve high-performance Li metal batteries

J Colloid Interface Sci. 2023 Sep:645:45-54. doi: 10.1016/j.jcis.2023.04.127. Epub 2023 Apr 28.

Authors

Linghao Zhang¹, Xin Xu¹, Sen Jiang¹, Lai Wei¹, Kang Xi¹, Yue Lei¹, Xiang Cheng¹, Junying Yin², Yunfang Gao³

Affiliations

¹ State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China.
² State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China; College of Chemical Engineering and Safety, Binzhou University, Binzhou 256603, China. Electronic address: junyingyin@bzu.edu.cn.
³ State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China. Electronic address: gaoyf@zjut.edu.cn.

PMID: 37146378
DOI: 10.1016/j.jcis.2023.04.127

Abstract

Solid-state Li metal batteries (SSLMBs) are one of the most promising energy storage devices, as they offer high energy density and improved safety compared to conventional Li-ion batteries. However, the large-scale application of SSLMBs at room temperature is restricted by the main challenges such as low ionic conductivity and poor cyclic performance. Herein, a composed polymer-in-salt electrolyte (CPISE) is fabricated, which is composed of polyvinylidene vinylidene hexafluoropropene (PVDF-HFP) and high-concentration Li bis(trifluoromethanesulphonyl)imide (LiTFSI), reinforced with natural halloysite nanotubes (HNTs). The High concentration of LiTFSI and introduced HNTs synergized with PVDF-HFP to provide more various Li⁺ transport pathways. Additionally, the backbones of the uniform dispersion of HNTs in the CPISE effectively boosts the physicochemical nature of the CPISE. As a result, the prepared CPISE achieves excellent mechanical strength, high ionic conductivity (1.23*10^-3 S cm^-1) and high Li⁺ transference number (0.57) at room temperature. Consequently, in existence of the CPISE, the Li symmetric cell cycles stably beyond 800 h at 0.15 mA cm^-2 and the LiFePO₄/Li cell displays impressive cyclic performance with capacity retention of 79% after 1000 cycles at 30 °C. Furthermore, the superiority and the functional mechanism of the CPISE are discovered in detail. This work provides a promising strategy for the development of high-performance SSMLBs at room temperature.

Keywords: Halloysite nanotubes; Li metal batteries; PVDP-HFP; Polymer-in-salt; Solid-state electrolyte.