Thin Li1.3Al0.3Ti1.7(PO4)3-based composite solid electrolyte with a reinforced interface of in situ formed poly(1,3-dioxolane) for lithium metal batteries

Yali Liu; Youlong Xu; Yuan Zhang; Cheng Yu; Xuekai Sun

doi:10.1016/j.jcis.2023.03.182

Thin Li_1.3Al_0.3Ti_1.7(PO₄)₃-based composite solid electrolyte with a reinforced interface of in situ formed poly(1,3-dioxolane) for lithium metal batteries

J Colloid Interface Sci. 2023 Aug 15:644:53-63. doi: 10.1016/j.jcis.2023.03.182. Epub 2023 Apr 5.

Authors

Yali Liu¹, Youlong Xu², Yuan Zhang¹, Cheng Yu¹, Xuekai Sun¹

Affiliations

¹ Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, China; Shaanxi Engineering Research Center of Advanced Energy Materials & Devices, Xi'an Jiaotong University, No. 28, West Xianning Road, Xi'an 710049, China.
² Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, China; Shaanxi Engineering Research Center of Advanced Energy Materials & Devices, Xi'an Jiaotong University, No. 28, West Xianning Road, Xi'an 710049, China. Electronic address: ylxu@mail.xjtu.edu.cn.

PMID: 37094472
DOI: 10.1016/j.jcis.2023.03.182

Abstract

Composite solid electrolytes (CSEs) exhibit great potential due to their advantages of both sufficient strength and high ionic conductivity. However, their interfacial impendence and thickness hinder potential applications. Herein, a thin CSE with good interface performance is designed through the combination of immersion precipitation and in situ polymerization. By employing a nonsolvent in immersion precipitation, a porous poly(vinylidene fluoride-cohexafluoropropylene) (PVDF-HFP) membrane could be rapidly created. The pores in the membrane could accommodate sufficient well-dispersed inorganic Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP) particles. Subsequent in situ polymerized 1,3‑dioxolane (PDOL) further protects LATP from reacting with lithium metal and supplies superior interfacial performance. The CSE has a thickness of ∼ 60 μm, ionic conductivity of 1.57 × 10^-4 S cm^-1, and oxidation stability of 5.3 V. The Li/1.25LATP-CSE/Li symmetric cell has a long cycling performance of 780 h at 0.3 mA cm^-2 for 0.3 mAh cm^-2. The Li/1.25LATP-CSE/LiFePO₄ cell exhibits a discharge capacity of 144.6 mAh/g at 1C and a capacity retention of 97.72 % after 300 cycles. Continuous depletion of lithium salts due to the reconstruction of the solid electrolyte interface (SEI) may be responsible for battery failure. The combination of the fabrication method and failure mechanism gives new insight into designing CSEs.

Keywords: Composite solid electrolytes; Dense morphology; Immersion precipitation; In situ polymerization; Superior interfacial performance.