Composite Electrolytes Based on Poly(Ethylene Oxide) and Lithium Borohydrides for All-Solid-State Lithium–Sulfur Batteries

作者：Xiang Zhang, Xiang Zhang, Tengfei Zhang, Yifei Shao, Hailin Cao, Zhenhua Liu, Shuai Wang, Xiaogang Zhang, Xiaogang Zhang · 发表于：ACS Sustainable Chemistry & Engineering · 年份：2021 · DOI：10.1021/acssuschemeng.1c00381 · 被引用次数：58 · 研究领域：Advanced Battery Materials and Technologies、Hydrogen Storage and Materials、Advanced Battery Technologies Research

Complex hydride LiBH 4 is a promising solid-state electrolyte (SSE) for rechargeable batteries, owing to its great compatibility with the lithium metal anode and good mechanical properties. However, LiBH 4 only exhibits high ionic conductivity (10 –3 S cm –1 ) with the hexagonal structure at temperatures above 117 °C. To overcome this obstacle, composite poly(ethylene oxide)–hydride electrolytes were synthesized by a solution-casting method. PEO–Li 4 (BH 4 ) 3 I (EO/Li + = 10) delivers the highest ionic conductivity of 4.09 × 10 –4 S cm –1 with high Li + transference number of 0.45 at 70 °C. The addition of nano-SiO 2 as an inorganic filler enhances the dendrite-free ability of electrolyte membranes dramatically and prolongs the cycle life of the Li symmetric battery from <100–360 h. In order to suppress the shuttling effect of polysulfide and volume expansion in lithium–sulfur (Li–S) batteries, sulfurized pyrolyzed poly(acrylonitrile) was selected as the cathode material for all-solid-state batteries, which presented a remarkable cycling stability of 232 (967 for sulfur content) mA h g –1 after 75 cycles. These attempts not only decrease the application temperature of LiBH 4 but also broaden the utilization of hydride in SSEs.