TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: In the solid polymer electrolyte: silicon-oxygen-lithium boron trifluoride groups of (I) are dissociated into silicon-oxygen-boron trifluoride ions and lithium ions, and the lithium ions are solvated by the poly(ethylene oxide); and lithium ions bridge silicon oxide boron trifluoride groups of (I) and ether oxygen of ethylene oxy (-(O-CH2-CH2)-) groups of (I) to form silicon-oxygen-boron trifluoride anion-lithium cation-ethylene oxy (OCH2-CH2)n linkages in the solid polymer electrolyte, where n is not defined.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The solvent is acetonitrile.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The composition has an oxygen to lithium ratio of 4:1-20:1, considering only ether oxygen in determining the ratio, preferably 8:1, 10:1, 12:1, 14:1, or 16:1. The composition/solid polymer electrolyte has a percent crystallinity of less than 4%, preferably less than 1%. The composition is a solid at room temperature. Preferred Components: The poly(ethylene oxide) has a viscosity average molecular weight of 100-1000K, preferably 600K. In the composition chains of poly(ethylene oxide) connect aggregates of (I). The phenyl groups of (I) comprise nanometer-sized clusters in the solid polymer electrolyte. Preferred Method: The composition is formed from self-assembly of the (I) and the poly(ethylene oxide). The process results in the formation of a film. EXAMPLE - Ethoxyethane-trifluoroborane (1:1) was added to dry polyoctahedral silsesquioxane-hepta phenyl tris lithium in an argon atmosphere at 25 degrees C and stirred for 1 hour. The reaction product, polyoctahedral silsesquioxane-hepta phenyl tris lithium boron trifluoride, was filtered and washed four times with a large excess of dichloromethane and dried at 80 degrees C in vacuum for 24 hours. Separate solutions of dry polyoctahedral silsesquioxane-hepta phenyl tris lithium boron trifluoride and dry poly(ethylene oxide) in anhydrous acetonitrile, were mixed or stirred for 6 hours, and acetonitrile was slowly removed at 90 degrees C for 30 hours under vacuum. Then the solution was added dropwise on a Teflon (RTM: Polytetrafluoroethylene) sheet to form films. The films were stored in a glove box at ambient temperature for 36 hours and then dried at 90 degrees C for 16 hours in vacuum to obtain polyoctahedral silsesquioxane-hepta phenyl tris lithium boron trifluoride complex/poly(ethylene oxide) films.