At present, the commercially available Lithium-ion batteries, although widely used for portable energy storage for military applications, still suffer a number of limitations including safety issues resulting from using liquid electrolyte, limited range of operation temperatures, and limited energy/power density partially because of using low voltage cathode, along with the employment of additional thermal management and safety component. In this project, Bioenno Tech proposes to develop a novel class of high voltage, high energy/power density solid-state Li-ion battery (SSLiB) that is based on an innovative polymer composite electrolyte and the associated unique electrode design and cell processing. The resultant LLSiB would be highly safe because of using solid-state electrolytes, and provide high energy density and power density, small footprint, various form factors/shape conformability that can be integrated into various military energy/power systems. The LLSiB can be fabricated with a low, scalable, roll-roll manufacturing process that can be implemented with an industrial production of existing Li-ion battery. The Phase I will focus on the feasibility investigations, including material/device design, processing development, characterizations, and prototype demonstrations.