Porous polymer electrolytes for long-cycle stable quasi-solid-state magnesium batteries

• 作者: Tiantian Wang Xudong Zhao Fanfan Liu Li-Zhen Fan
• 来源期刊: 能源化学
• 年，卷（期）: 2021,（8）
• 页码范围: 608-614
• 页数: 7页
• 语种: 英文

摘要

The development of applicable electrolytes is the key point for high-performance rechargeable magnesium batteries (RMBs).The use of liquid electrolyte is prone to safety problems caused by liquid electrolyte leakage.Polymer-based gel electrolytes with high ionic conductivity,great flexibility,easy processing,and high safety have been studied by many scholars in recent years.In this work,a novel porous poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) membrane is prepared by a phase inversion method.By immersing porous PVDF-HFP membranes in MgCl2-AlCl3/TEGDME (Tetraethylene glycol dimethyl ether) electrolytes,porous PVDF-HFP based electrolytes (PPEs) are formed.The PPE exhibits a high ionic conductivity (4.72 × 10 4 S cm-1,25 ℃),a high liquid electrolyte uptake of 162％,as well as a wide voltage window (3.1 V).The galvanostatic cycling test of Mg//Mg symmetric cell with PPE reveals that the reversible magnesium ion (Mg2+) plating/stripping occurs at low overpotentials (～0.13 V).Excellent long cycle stability (65.5 mAh g-1 over 1700 cycles) is achieved for the quasisolid-state RMB assembled with MoS2/C cathode and Mg anode.Compared with the liquid electrolyte,the PPE could effectively reduce the side reactions and make Mg2+ plating/stripping more uniformly on the Mg electrode side.This strategy herein provides a new route to fabricate high-performance RMB through suitable cathode material and polymer electrolyte with excellent performance.