NASA has a need to develop higher energy density battery systems to meet the power requirements of future energy devices. In this proposed Phase I program, PSI will develop an advanced cathode electrode structure that allows for the construction of lithium ion cells with long life (>250 cycles) and energy densities 265Wh/kg. The novel cathode electrode will reduce detrimental reactions with the electrolyte at high voltages that result in inefficient cycling and enhance performance fade. Initially, PSI will demonstrate the feasibility of the proposed approach by constructing and performing steady state cycling of lab sized silicon/cathode cells. This testing will highlight the ability to construct cells that can maintain their performance over hundreds of cycles. Scale-up of the optimized processes will then be carried out to support construction of prototype Ah sized cells and demonstrate MRL and TRLs of 4. Phase II efforts would focus on construction of larger cells, demonstrating the cycling performance, and the readiness of the technology for integration into prototype battery packs for initial field testing.