Power source system based on high performance battery is one of key enabling technologies for the new generation of electric vehicles (EVs). Solid-state lithium-ion batteries (SSLiBs) with high energy/power density, wide operation temperature range, high flexibility and long cycle life will provide an attractive solution. In particular, when compared to conventional LiBs, SSLiBs offers an excellent safety due the elemination of flammable and harzard liquid electroltye. In this SBIR project, Bioenno Tech proposes to develop a novel class of rare-earth-oxide (REO)-enhanced high-voltage LiNiPO4 cathodes. The resultant SSLiBs would exhibit substantially improved performance including higher operation voltages and high enenrgy/power densities when compared to conventionally used products. This project will focus on (1) Design, demonstration and cost-effective manufacturing of high voltage cathode materials that are enhanced through REO-based co-doping strategy; and (2) Prototyping and demonstration of SSLiB pouch cell through our established processing procedure to evaluate cathode properties and provide reference for further optimization. Phase I will focus on the feasibility demonstration of the proposed technical approach, through material design, process development, characterizations, and protoyping and tests. Underlying technical issues that govern the fabrication and performance of rare-earth-oxide (REO)-enhanced high-voltage LiNiPO4 cathodes and resultant novel SSLiBs will be identifed and addressed. The proposed rare-earth-oxide (REO)-enhanced high-voltage LiNiPO4 cathodes and resultant SSLiB technology will be crucial enabling technology for the new generation EVs. Once successfully developed, these SSLiBs will find wide applications in various future EVs (also include hybrid and/or plug-in hybrid electric vehicles, HEVs/PHEVs) that require higher energy/power density, excellent safety, wide working temperature range, and longer service/cycle life. Other possible applications include power sources in sensors, mobile electronics, aircraft, and renewable energy storage systems. Based on the integration of these SSLiBs, the system can be made lighter, smaller, with lower costs and less waste heat generation, and lower greenhouse gas (GHG) emissions.