Design and optimization of a novel flow field structure to improve the comprehensive performance of vanadium redox flow batteries

Abstract

Vanadium redox flow battery (VRFB) is an essential technology for realizing large-scale, long-term energy storage. Among its components, the flow field structure plays a crucial factor affecting the battery performance. So far, there still exists uneven electrolyte distribution leading to low efficiency. To this end, inspired by the excellent nutrient transfer process of leaf veins in nature, this work proposed a flow field design of bionic leaf veins and innovatively adds obstructions in the main channel, with the aim of utilizing the diversion effect to substantially enhance the electrolyte's distribution uniformity and the mass transfer capability. Next, the validity of the model is verified by simulation, and a single cell is fabricated for experimental verification with multiple charge-discharge cycles. The analyzed results show that the energy efficiency (EE) of this study is improved by 1.983 % under the same conditions compared to the serpentine flow field. The design mechanism, which effectively improves the transport characteristics of the active material in the VRFB, serves as a reference for future flow field structure designs.