Inorganic Electrolyte Membranes for Redox Flow Batteries

Inorganic Electrolyte Membranes for Redox Flow BatteriesZhi Xu , Ioannis Michos , Ruidong Yang ,Junhang DongDepartment of Chemical Engineering , University of Cincinnati , Cincinnati , OH 45221 , USA Redox-flow batteries (RFBs) are emerging as useful means of electrical energy storage for distributed renewable power systems and large-scale grids because of a number of advantages such as low cost and small environmental footprint. The RFB operates by electrode reactions of dissolved metal ions constituting red-ox couples. The RFB operation is enabled by internal transfer of non-reactive ions , often protons , through an ion exchange membrane (IEM). Conventional IEMs are made of ionic polymers such as perfluorosulfonic polymers which have shortcomings of relatively low ion selectivity and long term material instability. This presentation reports our recent demonstration of purely inorganic nanoporous membranes as an alternative IEM in vanadium RFB (VRFB). We will discuss the operation principles of the new type of nanoporous inorganic IEM and the performance of the new IEM equipped RFB.