Lithium Battery Polymer Electrolytes

US Army missions require a safe, long-cycle-life lithium battery that is rechargeable, efficient and reliable for powering electronics for future soldier sytsems applications. A solid polymer electrolyte for lithium batteries will allow placement of the electrodes in close proximity, bipolar cell constrution, and retardation of undesirable chemical reactions to meet US Army requirements for the secondary Li batteries which can potentially deliver an energy density of 200 Wh/kg and a power density of 40 W/kg. This R&D program focuses on the synthesis of novel organic salts, and polymer electrolytes based on these salts to achieve a structure of improved Li+ ion conductivity. Such a polymeric separator is expected to be stable in the chosen Li/MnO2 cell chemistry. The program objectives also include developing Li-intercalation cathodes and testing these components in a flat configuration to demonstrate the feasibility of a high energy density, compact yet safe, secondary lithium battery to meet the space mission requirements. The Phase I program will concentrate upon the development of a nevel stable solid polymer electrolyte, which is a host structure to a high conductivity medium for Li+ ions and to demonstrate the feasibility of improved Li/MnO2 cells using these polymer electrolytes. The Phase II efforts will be devoted to the development of Li-insertion anodes, high voltage cathodes, design, fabrication, and testing of battery prototypes which will utilize the new high conductivity polymer electrolytes for mission-specific US Army applications.