This Small Business Innovation Research Phase I project aims to develop an inorganic-reinforced proton exchange membranes for application in vanadium redox flow batteries (RFBs). New proton exchange membranes with reduced vanadium permeability as well as enhanced stability and durability are needed for cost-effective operation of RFBs. The composite membrane to be developed will have high chemical stability in RFB electrolytes, high proton conductivity, and low permeability of vanadium ions, along with high dimensional stability, high mechanical strength, and high durability. The project will establish composition-processing-property relations of the novel composite membrane through detailed characterization. The performance of the membrane for vanadium RFBs will also be evaluated. Issues related to scale up of the membrane production will be identified and addressed.
The broader/commercial impact of this project, if successful, will advance the development of RFB technology for stationary electrical energy storage. The feature of decoupling between the energy and power, and the extremely large capacities possible from RFBs make them well suited to use in large power storage and high output applications such as for transmission grid operations, in helping to average out the production of highly variable generation sources such as wind or solar power. RFBs'rapid response times also make them well suited to uninterrupted power supply (UPS) type applications.
This Small Business Innovation Research project aims to develop an inorganic-reinforced composite proton exchange membrane (PEM) for application in vanadium redox flow batteries (RFBs). New PEMs with reduced vanadium permeability as well as enhanced stability and durability are needed for cost-effective operation of RFBs. In Phase I, the new composite PEM was prepared by a solution casting process, and characterized in terms of structural and microstructural features, RFB-relevant properties such as mechanical strength, chemical stability, proton conductivity, water swelling, dimensional stability, and permeability of vanadium ions. The performance of the composite PEM was evaluated in terms of OCV retention and charge-discharge characteristics in a single cell of the vanadium RFB. The composite PEM attains proton conductivity comparable to Nafion 117 (ranging from 80 % to 100% of the conductivity measured from Nafion 117), the same high chemical stability as Nafion membranes in RFB electrolyte solutions, lower permeability of vanadium ions, lower water swelling, higher dimensional stability, higher mechanical strength than Nafion 117. The composite PEM seems to have clear advantages over Nafion 117 for vanadium RFB applications as it shows better charge-discharge performance and longer OCV retention in vanadium RBF cells than Nafion 117. The development of high-performance proton exchange membranes will advance the RFB technology for stationary electrical energy storage. The feature of decoupling between the energy and power, and the extremely large capacities possible from RFBs make them well suited to use in large power storage and high output applications such as for transmission grid operations, in helping to average out the production of highly variable generation sources such as wind or solar power. The rapid response times of RFBs also make them well suited to uninterrupted power supply (UPS) type applications.
