Elucidation of Cell Design and Performance of a Portable, Modular Vanadium Redox Flow Cell

Vanadium redox flow (VRF) batteries are a promising technology for stationary energy storage due to their longer life cycles and flexibility in design. In this study, a novel flow cell structure is designed which constitutes high-density polyethylene (HDPE) end plates, and engraved parallel flowfield in the electrode frame of acrylic plates to improve safety, extend life, and promote ease of assembly of components than conventional VRF cells. Particularly, HDPE end plates possess a design that consists of slots wherein all components of half-cell interlock effectively in a modular and portable boxed arrangement. This new design addresses the key challenges of conventional VRF cells such as electrolyte leakages, corrosion of the metallic components, complications in compression, and misalignments during assembly. The charge-discharge characteristics of a range of vanadium concentrations and flow rates are performed in a newly designed VRF cell prototype. The results show that the new cell design keeps the cycling performance stable, and exhibits 85.5-96.5% voltaic, coulombic, and energy efficiency. Additionally, the important cell attributes comprising state-of-charge, and current density have also been assessed.