Membrane evaluation for vanadium flow batteries in a temperature range of −20–50 °C

Vanadium flow battery (VFB) is one of the most promising large-scale energy storage technologies because of super long lifespan and unlimited capacity. In depth study of the all-climate (wide temperature) properties of VFB is essential to the practical application of VFB around the whole globe. In this work, we established a wide temperature (−20–50 °C) research platform for VFB single cell evaluation. A series of typical cation exchange membranes (i.e. the benchmark Nafion 115 and Nafion 212, the Selemion CMV, and the promising candidate SPEEK) and anion exchange membranes (i.e. the Selemion AMV and APS) are studied in terms of their VFB efficiencies, long-term cycling stability and capacity fading mechanism in a temperature range of −20–50 °C. Moreover, the desirable membrane for VFB application under different temperature conditions is also discussed and suggested.