Development of hierarchical ion conductive membranes for flow batteries

As the share of renewables in the electrical grid increases, it is necessary to develop and implement large-scale energy storage systems to prevent grid instabilities. Hydrogen bromine (HBr) and salinity gradient flow batteries are an attractive solution as they use abundant, safe, and cheap materials (namely, water and hydrogen bromine or sodium chloride). Nonetheless, the deployment of these batteries on a large scale is highly limited, among others, by the lack of performant and cheap membranes.

Therefore, the goal of this research is to focus on the development and testing of ion exchange membranes that have a low resistance, high permselectivity, reduced water transport, and a long lifetime.

This research will focus on the synthesis of membranes with improved properties thanks to, for example, supramolecular organization by using polymers with specific properties (e.g. liquid crystalline polymers, amphiphilic molecules, …). Furthermore, the long-term stability of the membranes will also be improved by investigating the effects of crosslinking. The obtained membranes will be characterized both in terms of their properties (charge density, water permeability, selectivity, …) and performances (power and energy densities, cyclability, …). Ultimately, the membranes will be tested in HBr and salinity gradient batteries under realistic operating conditions.