Selective Ion Transport in Microporous Inorganic Membranes and Potential Applications As Battery Electrolyte Membranes

Redox-Flow Batteries (RFBs) have gained immense attention because of their unique advantages such as separate power and storage, low cost, and small environmental impact. Commercial demonstrations of large scale RFB units as energy storage devices for renewable power systems and large-scale grids are now being carried out in many countries around the world. However, fundamental researches are still needed to improve the cell reliability, energy efficiency and cost effectiveness. The ion exchange membrane (IEM), a central piece of the RFB, is currently a main subject of research because all the IEMs are made of ionic polymers which have the issues of relatively low ion selectivity and long-term material instability. This presentation reports our investigation of ion selective diffusion through nanoporous ceramic membranes and its potential use as IEMs in RFBs. We will discuss the ion permeability and selectivity of the membranes and their performance as IEM in RFB in terms of power density, energy efficiency, and charge-discharge behavior.