Electrode/Electrolyte Interfaces in Li/SPE Batteries

All solid-state lithium secondary batteries have the potential to offer energy densities that are 4-5 times greater than the existing battery systems. However, several technological problems have to be solved before a full realization of their potential. The principal challenge is the stability of the solid polymer electrolytes (SPE). Currently, all lithium-SPE systems exhibit increasing cell impedence with cycles, leading to loss of capacity and poor cycle life. While the exact nature of the interfacial behavior is not yet well understood, it is clear that a proper understanding and elimination of the interfacial impedance problem is paramount to the development of long cycle-life lithium batteries. We propose an attempt to synthesize some truly ionic, lithium conducting polymers and the construction and study of all solid-state LixC6/SPE/Mn2O4 systems. A well characterized PEO system as control will be compared to the new electrolyte systems with rspect to conductivity and cell performance. The interfacial behavior of these electrolytes with both the electrodes will be studied using corss-sectional and morphological examinations, infrared spectroscopy and x-ray diffraction of cell components and impedance and other electrochemical behavior of the cells, all as a function of to be determined by cycle intervals.