The modern warfighter has access to a wide array of tactical, communication, navigation, and health sensors, monitors, and displays that require robust power sources to truly confer an advantage on the battlefield. Conventional lithium-ion (Li-ion) batteries typically fall short of energy density requirements for these systems and also pose safety risks. To address this need, Solid Power, Inc. (Solid Power) proposes to advance its solid-state battery system to exceed the energy density, stability, and safety of conventional Li-ion cells while also allowing for mechanical flexibility. Solid Power will leverage its highly energy dense solid state material system while replacing the typical Li metal anode with a high capacity alloy anode. Phase I will culminate with the demonstration of 250 mAh conformal pouch cells with >250 Wh/kg along with a path to >350 Wh/kg during Phase II.