Advanced power is critical to NASA to meet future space exploration missions. NextGens innovative rechargeable battery solution goes far beyond lithium-ion for long duration energy storage to support lunar surface operations. NextGen, in collaboration with NEI Corporation, is proposing an advanced solid-state lithium-battery that takes advantage of the outstanding properties of two novel materials for the electrolyte and cathode in conjunction with a lithium-metal anode. The result is a safe, lightweight system that combines high energy density (>400 Wh/kg) and high power (~10 C) with high cell voltage (nominal voltage of 4.6 V) to allow the use of fewer cells for the required module. The main enabler of this performance is an innovative high ionic conductivity, high-voltage, flexible solid composite electrolyte with outstanding performance over a wide temperature range. During the proposed six-month effort, NextGen will synthesize the solid composite electrolyte system, characterize its electrochemical and thermal performance, and integrate with its proprietary high-voltage, high-capacity, cobalt-free cathode (LMOX) and a lithium-metal anode into both coin and pouch cells. Testing will include electrochemical stability, cell capacity, charge/discharge rate performance, cycle life, and both high- and low-temperature performance. At the conclusion of Phase I, NextGen will deliver ten 1.2 Ah pouch cells to NASA meeting its performance requirements. SOA and KPP: Specific energy (Wh/kg): SOA = ~200, Proposed = 400 Nominal voltage (V): SOA = 3.7, Proposed = 4.6 Cycle life: SOA= <1000, Proposed = >1000 Temperature range (°C): SOA = 0 to 35, Proposed = -20 to 70 NextGens proposed solution provides a 2X increase in capacity, a 25% increase in voltage, and a 3X increase in temperature range. The enhanced capacity either reduces weight or enables new performance while the higher voltage minimizes the number of cells required, both reducing weight and simplifying power systems. Potential NASA Applications (Limit 1500 characters, approximately 150 words) Long-duration, high-capacity, high-power, high-voltage and high-energy storage for lunar and planetary surface operations (landers, habitats, science platforms, robotic and crewed rovers), aerial operations, large and small satellite systems. Enhanced capacity either reduces weight or enables new performance while higher voltage minimizes the number of cells required, both reducing weight and simplifying power systems. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words) High-capacity, high-power, high-energy storage over a broad temperature range for powering electric and hybrid-electric vehicles, grid storage, portable electronics (mobile phones, laptop computers, etc.), military applications (e.g., Conformal Wearable Battery, remote sensor systems, sonobuoys), power tools. Cobalt-free cathode lowers cell cost.