Completed NASA Game Changing Development project led by Glenn Research Center to mature a bifurcated reversible alkaline cell for lunar energy storage. The project targets a 2 kW electrolysis and 1 kW fuel-cell breadboard, raising the technology from TRL 3 toward TRL 4 while combining water electrolysis and regenerative fuel-cell operation for higher energy density, fewer components, in-situ resource utilization, life support oxygen, and eclipse-period power.