Enhanced Electrochemical Properties of Gel Polymer Electrolyte with Hybrid Copolymer of Organic Palygorskite and Methyl Methacrylate.

Lanlan Tian,Haijun Guo,Xuefang Chen,Hairong Zhang,Lian Xiong,Xinde Chen

doi:10.3390/ma11101814

Abstract

Gel polymer electrolyte (GPE) is widely considered as a promising safe lithium-ion battery material compared to conventional organic liquid electrolyte, which is linked to a greater risk of corrosive liquid leakage, spontaneous combustion, and explosion. GPE contains polymers, lithium salts, and liquid electrolyte, and inorganic nanoparticles are often used as fillers to improve electrochemical performance. However, such composite polymer electrolytes are usually prepared by means of blending, which can impact on the compatibility between the polymer and filler. In this study, the hybrid copolymer poly (organic palygorskite-co-methyl methacrylate) (poly(OPal-MMA)) is synthesized using organic palygorskite (OPal) and MMA as raw materials. The poly(OPal-MMA) gel electrolyte exhibits an ionic conductivity of 2.94 × 10−3 S/cm at 30 °C. The Li/poly(OPal-MMA) electrolyte/LiFePO4 cell shows a wide electrochemical window (approximately 4.7 V), high discharge capacity (146.36 mAh/g), and a low capacity-decay rate (0.02%/cycle).

Highlights

Rechargeable lithium batteries (LIBs) have long been regarded as the most promising energy storage technology for various portable electronics, electric cars and energy storage systems [1,2].Generally, the use of liquid organic solvents as an electrolyte in lithium batteries raises safety concerns, owing to the possible leakage of corrosive electrolytes and the risk of spontaneous combustion and explosion when batteries are subjected to high temperatures and/or violent impacts [3]
The use of liquid organic solvents as an electrolyte in lithium batteries raises safety concerns, owing to the possible leakage of corrosive electrolytes and the risk of spontaneous combustion and explosion when batteries are subjected to high temperatures and/or violent impacts [3]
Liquid electrolytes can react with the lithium anode metal to form “dead lithium”, which limits liquid electrolyte use in LIBs [4]

Summary

Introduction

Rechargeable lithium batteries (LIBs) have long been regarded as the most promising energy storage technology for various portable electronics, electric cars and energy storage systems [1,2]. In order to increase the ionic conductivity of polymer electrolytes, many organic and inorganic modifiers, such as polyvinylidene fluoride (PVDF) [16], poly (vinylidene fluoride-hexafluoropropylene) (poly (VdF-HFP)) [17], poly (vinyl chloride) (PVC) [18], SiO2 [19], TiO2 [20], Al2 O3 [21] and clay, are added into the polymer matrices Clays such as montmorillonite and palygorskite (Pal) have several distinct advantages as fillers, namely: A high aspect ratio (∼1000), high cation-exchange capacity, large specific surface area and appropriate interlayer charge [22,23,24]. A coin-type cell was assembled using poly(OPal-MMA) as the separator, lithium as the anode and lithium iron phosphate (LiFePO4 ) as the cathode and the electrochemical characteristics of poly(OPal-MMA), such as its ionic conductivity, electrochemical window and cycling performance, were evaluated

Materials

Results

Electrochemical Characterization of Polymers

Conclusions