Advanced High Energy Lithium Polymer Electrolyte Battery

This program is directed toward synthesis of two closely related classes of new lithium ion conducting polymer electrolytes which hold promise of achieving both higher ionic conductivity and improved elastomeric properties over current state-of-the-art polymer electrolytes. Approaches to be used for synthesis of these two materials will be based upon, (i) the modification of polycarbonate hosts by poly(dimethyl siloxane) and multifunctional silanes, and (ii) introducing cyclic carbonates into poly(dimethyl siloxane) matrix. Both of these related strategies exploit the idea that carbonate oxygens, within the single phase carbonate-siloxane polymer matrix, will facilitate extensive ionic dissociation of introduced lithium salts, and that furthermore elastomeric behavior of the matrix under ambient temperature conditions will lead to enhanced mobility of lithium ions. This would permit small inter-electrode distances to be achieved within portable secondary lithium batteries incorporating these new polymer electrolytes. Following verification of high lithium ion conductivity in these polymeric materials and their elastomeric phase under ambient or close to ambient temperature, they will be incorporated into lithium cells and their reversible electrochemical performance evaluated. BENEFITS: A new class of lithium ion conducting polymer electrolytes to emerge from this investigation, possessing both ionic conductivities 10(-3) S/cm and improved elastomeric properties compared to currently available technology, will find commercial application in high performance portable secondary lithium batteries. Performance of these devices is currently limited by inadequate combinations of ionic conductivity and electrochemical stability, that will be resolved in this program.