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(Mg^(2+))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 Mg^(2+)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.
基金
supported by the National Key Research and Development Program of China(2017YFE0113500)
the National Natural Science Foundation of China(51872027)。