High-Performance Nanoparticle-Modified Membrane for Redox Flow Batteries

There is an increasing need for improved grid-level energy storage to accommodate both intermittent, renewable power generation sources (e.g., wind, solar) and to provide increased distributed grid-level power storage. Redox flow batteries (RFB) can meet these demands with flexible design parameters and good cycle life, providing an approach to energy storage required by large-scale utilities. While significant advances have been made in improving the performance and cost of the system, there remain several issues that need to be improved. One area is the membrane, representing 20%–30% of the cost of the system depending on the type of RFB. The membrane also represents a critical part of the stack and significantly affects the overall power density and efficiency of the RFB. In addition, the membrane separates the reactants. As a result, it allows selective transport of ions during the charge and discharge reactions, preventing the transport of the redox ions used to store the energy. There is, therefore, a significant need for improved, low-cost, high-performance membranes to enhance the performance and durability of the RFB, lowering the overall costs towards the target of $100/kWh-1. Mainstream proposes to develop an innovative nanoparticle-modified hydrocarbon-based membrane. The membrane properties will be optimized to provide the optimal balance between conductivity, power density, and selectivity, improving energy density, reliability, and durability. Improved membranes for redox flow batteries are expected to provide improved power storage for grid load-leveling and capture intermittent renewable energy sources.