| abstract |
Secondary batteries with conjugated poiymer anodes, such as polyacetylene, contain an electrolyte including a salt of the formula MBR 4 -w-y-zR'wR"yXz wherein M is an alkali metal, B is boron, R is alkyl, R' is aryl or alkyl-substituted aryl, R" is heterocycle, X is F, Cl, Br, I, CN, OCN, SCN, fluoroaryl or perfluoroalkyl-substituted aryl, w and y are integers of 0 to 4, and z is an integer of 0 to 4, provided that when X is solely F, Cl, I, Br, CN, OCN, SCN or perfluororalkyl, Z is not 4; with the sum x+y+z being equal to or less than 4. Exemplary salts are LiBMe4, LiBMe2Ph2, LiBMe2PhPy, LiBMe2Py 2 and KBPh 3 SCN (where M = methyl, Ph = phenyl and Py = pyrrolyl). Cathodes such as conjugated backbone polymers (e.g. polyacetylene) and transition-metal chalcogenides (e.g. TiS2) are disclosed. The battery can be charged to a state wherein the anode is in a reduced state of 0.1V-0.5V (relative to M/M + ) where a voltage plateau exists in some instances. |