Colorado School of Mines

The Colorado School of Mines will develop a new membrane for redox flow battery systems based on novel, low-cost materials. The membrane is a hybrid polymer that includes heteropoly acid molecules and a special purpose fluorocarbon-based synthetic rubber called a fluoroelastomer. The team will enhance the membrane's selectivity by refining the polymer structure, employing crosslinking techniques, and also through doping the polymer with cesium. The fluoroelastmer is commercially available, thereby contributing to a superior performance-to-cost ratio for the membrane. Flow battery experts at Lawrence Berkeley Laboratory will extensively test the selectivity, conductivity, and stability of the membranes developed in this project, and 3M will apply its decades of membrane fabrication experience to scale-up the new technology. If successfully developed, the separator in this project will increase efficiency and reduce cost in existing flow battery systems such as the all-iron redox flow battery.

If successful, developments made under the IONICS program will significantly reduce battery storage system costs for the grid to about $150/kWh (for a 5-hour discharge time, on a fully installed basis), a cost point that transforms the grid by enabling cost-effective electrical energy storage.