A gel polymer electrolyte based on PVDF-HFP modified double polymer matrices via ultraviolet polymerization for lithium-sulfur batteries

Xiaojing Hao; Hongyan Wenren; Xiuli Wang; Xinhui Xia; Jiangping Tu

doi:10.1016/j.jcis.2019.09.116

A gel polymer electrolyte based on PVDF-HFP modified double polymer matrices via ultraviolet polymerization for lithium-sulfur batteries

J Colloid Interface Sci. 2020 Jan 15:558:145-154. doi: 10.1016/j.jcis.2019.09.116. Epub 2019 Sep 30.

Authors

Xiaojing Hao¹, Hongyan Wenren², Xiuli Wang³, Xinhui Xia¹, Jiangping Tu¹

Affiliations

¹ State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
² Zhejiang GBS Energy Co., Ltd, Yuyao, China.
³ State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China. Electronic address: wangxl@zju.edu.cn.

PMID: 31586734
DOI: 10.1016/j.jcis.2019.09.116

Abstract

Currently, as a new kind of separator, gel polymer electrolytes (GPEs) not only should play a role to separate cathode and anode, but also should have high ionic conductivity to guarantee the elevated electrochemical performances. As for quasi-solid-state lithium-sulfur batteries (LSBs), it is also very important to confine the shuttle effect and Li dendrite growth. Herein, we synthesize GPEs polymerized under ultraviolet, in which the poly(vinylidene fluoride-hexafluoro propylene) (PVDF-HFP) is one of the polymer matrices to provide high ionic conductivity and toughness, pentaerythritol tetrakis-divinyl adipate (PETT-DA) is another polymer matrix to simultaneously suppress shuttle effect and lithium dendrite. More importantly, Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (LLZTO) provides the Li⁺ transport sites to facilitate the Li⁺ transport speed. Meanwhile, it can hinder the crystallization of polymers, reducing crystallinity of GPEs. Prominently, the designed GPEs with 10 wt% LLZTO have elevated ionic conductivity of 8.74 × 10^-4 S cm^-1 and Li⁺ transference number of 0.69, accompanied with superb capacity retention of 88.6% after 300 cycles at 1C. Importantly, the excellent mechanical properties and thermal stability give more potentials to the commercialization of LSBs.

Keywords: Gel polymer electrolyte; Lithium-sulfur battery; Quasi-solid-state; Ultraviolet polymerization.