NASA Space Science missions require energy systems with high energy density with power levels up to several kW. Advances in mission electronics technology have resulted in smaller, lighter components yet power and energy requirements are increasing. RBC Technologies proposes to work with Moltech Power Systems to develop a novel electrochemical system, silver metal-hydride. This cathode/anode combination offers potential for very high energy with high specific power. Working prototype cells will be prepared in the Phase I effort. The ultimate program goal will be to demonstrate a sealed cylindrical cell that can achieve 140 Wh/kg and 1800 W/kg. Innovation will be required to develop separator materials that can simultaneously meet the electrochemical requirements of silver cathode and metal hydride anode. Full-scale battery development including shock and vibration hardening appropriate to the application would take place in Phase II, if awarded.