Projects

Membraneless hydrogen-bromine flow battery

Redox flow batteries can provide geographically flexible and highly efficient solution for renewable energy storage. The hydrogen-bromine flow battery investigated in this project is one example allowing particularly high current densities as compared to zinc-bromine, all-vanadium and other flow batteries. Yet the market penetration of flow batteries has been significantly limited by high system costs, in particular that of the ion-exchange membrane that separates the anode and cathode to prevent the intermixing of the positive and the negative electrolyte. In addition, the membrane lowers the battery output voltage due its high ohmic resistance.

This project seeks to develop and scale up a hydrogen-bromine flow battery there the ion-exchange membrane is replaced by a significantly cheaper and less resistive porous separator. Its higher electrolyte permeability is compensated by the use of porous cathode materials and complexing agents that reduce bromine diffusion, leading to the general design as shown in the picture below.

The research is challenging since to achieve the best performance it requires a combined optimization of both mechanical parameters, e.g. battery cell design and electrolyte flow rates, and chemical properties, e.g. electrolyte composition and cathode modifying treatment. The effect of the latter on the battery performance is exemplified in the picture below.

The research on this project is conducted by a team comprising the M.Sc. student Daniel Alfisi (battery design and operation), the Postdoctoral fellow Dr. Arunchander Asokan (battery scale-up and cathode optimization) and the Lab Manager Dr. Robert Gloukhovski (resistance measurements and data analysis).