Application of SPEEK membrane and Nafion membrane in vanadium redox flow battery

The water saturation ratio,expansion rate,resistance of vanadium and charge-discharge performance of two proton exchange membrane,Nafion membrane and SPEEK membrane,in vanadium redox flow battery prototype were researched.The reasons for these differences were analyzed on the basis of the basic chemical structures of the two kinds of diaphragms.The static test results show that: the water saturation ratio and the expansion rate of the SPEEK membrane is greater than the Nafion membrane,and the resistance of vanadium performance is better than the Nafion membrane.The charge-discharge test results in the vanadium redox flow battery prototype show that the proton exchange ability of Nafion membrane is greater than that of SPEEK membranes.The different performance between SPEEK membranes and Nafion membrane may be related to the differences of both chemical skeleton structure and sulfonated groups.