Towards cost-effective proton-exchange membranes for redox flow batteries: A facile and innovative method

摘要

To develop cost-effective ion-exchange membrane is of great importance for the large-scale industrialization of flow batteries. In this work, a novel method is proposed to prepare ion-selective microporous membranes based on non-electrolytic polymers. For the first time, poly (vinylidene fluoride) (PVDF) membranes with symmetric microporous structure is prepared via a facile and innovative method, and is successfully applied as proton-exchange membranes for vanadium redox flow batteries. Methods to tailor the proton conductivity and the ion selectivity of the membranes are illustrated and the performance of the PVDF microporous membrane on a vanadium flow battery unit cell is measured. The energy efficiency of the cell reaches as high as 78% at the current density of 100 mA cm(-2) and shows excellent stability during the charge-discharge cycling test.