Unitized High Pressure Regenerative Fuel Cell Stack for NASA Applications

Unitized regenerative fuel cells (URFCs) are promising candidates for power sources for future Mars and crewed lunar missions, as they offer added benefits of reduced mass and footprint compared to the traditional regenerative fuel cell (RFC) systems.nbsp; NASA seeks development of high pressure reversible or unitized proton exchange membrane RFC stacks that can meet (i) 2,500 psig balanced pressure operation, (ii) Round-trip efficiency of gt; 48% based on higher heating value measured at 500 mA/cm2 in fuel cell mode and 1,500 mA/cm2 in electrolyzer mode, and (iii) gt; 170 cycles with a target of up to 366 hours of operation per cycle in each mode (meaning ~ 62,000 hours operational durability!).nbsp; To address these requirements, Lynntech will leverage its prior URFC stack design, catalyst and membrane materials experience, and develop advanced URFC stacks with emphasis on materials selection for high-pressure hydrogen and oxygen compatibility, amphiphilic corrosion resistant diffusion layer for reversible oxygen electrode, and stack design for balanced high-pressure operation.nbsp; In the Phase I project, Lynntech will target the demonstration of stack and components at the single or short cell stack level and establish the stack design for a multi-kW URFC stack for the Phase II prototype demonstration.