Facile Preparation of EVOH-Based Amphoteric Ion Exchange Membrane Using Radiation Grafting Technique: A Preliminary Investigation on Its Application for Vanadium Redox Flow Battery.

Kangjun Xie,Yicheng Wang,Zhen Dong,Maolin Zhai,Long Zhao,Wei Qi

doi:10.3390/polym11050843

Abstract

A novel amphoteric ion exchange membrane (AIEM) was successfully prepared by one-step radiation grafting of sodium styrene sulfonate (SSS) and dimethylaminoethyl methacrylate (DMAEMA) onto ethylene-vinylalcohol copolymer (EVOH) powder and sequent transferring into film by casting method. Fourier transform infrared spectrometry (FT-IR), thermal gravimetric analyzer (TGA) and elemental analysis testified SSS and DMAEMA were successfully grafted onto EVOH. The ion exchange capacity, water uptake and proton conductivity of the resulting AIEM increased with grafting yield (GY). At the GY of 40.9%, the permeability of vanadium ions of AIEM was 3.98 × 10−7 cm2 min−1, which was better than Nafion117 membrane. Furthermore, the cost of this AIEM is much lower than that of Nafion117 membrane. This work provided a low cost and simple method for fabrication of the ion exchange membrane for vanadium redox flow battery (VRFB). Meanwhile, it also provided a new direction for the application of EVOH.

Highlights

As a promising large-scale form of energy storage, the vanadium redox flow battery (VRFB) has attracted wide attention due to its high energy efficiency, long cycle life, high safety, low cost and environmentally friendly nature [1]
sodium styrene sulfonate (SSS) and dimethylaminoethyl methacrylate (DMAEMA) were grafted onto ethylene-vinylalcohol copolymer (EVOH) powder using one step electron-beam-induced
A novel EVOH-based amphoteric ion exchange membrane (AIEM) was successfully synthesized by the combination of one step radiation grafting of SSS and DMAEMA, and a casting method

Summary

Introduction

As a promising large-scale form of energy storage, the vanadium redox flow battery (VRFB) has attracted wide attention due to its high energy efficiency, long cycle life, high safety, low cost and environmentally friendly nature [1]. The VRFB operates by utilizing two redox reactions of V (II)/V (III) and V (IV)/V (V) couples in the negative and positive electrolytes separated by the ion exchange membrane [2]. The function of the ion exchange membrane is to allow transport of ions to complete the circuit and prevent the mixing of the negative and positive electrolytes [3]. As a key component of VRFB, a desirable ion exchange membrane should have high proton conductivity, good chemical stability, low vanadium ion permeability and low cost [4]. As a most widely used commercial membrane, Nafion membrane has high proton conductivity and good chemical stability [5]. The high vanadium ion permeability of the Nafion membrane causes self-discharge of VRFB and results in decreasing of energy efficiency of VRFB [6]. There have been extensive research activities towards the modification of Nafion-based membrane to reduce its vanadium ion permeability

Methods

Results

Conclusion