TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Component: The cell further comprises a carrier, where the salt that provides overcharge protection is oxidized at a potential that changes with the dielectric constant of the carrier.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The electrolyte further comprises a nonreversibly oxidizable salt including lithium. The salt that provides overcharge protection is Li2Bl0H0-7Z3-10 (A), Li2Bl0Cl10, Li2B10H1-5Cl5-9, Li2Bl0Cl5-9(OR)1-5, Li2B10H2Cl8; Li2B10H0-7(OCH3)3-10, Li2B10C8(OH)2, Li2B10Br10, Li2B8Br8, Li2B12Cll2, or Li2B12I2. The salt that provides overcharge protection comprises a salt of formula Li2B10X10 or Li2B12Xl2. The salt can also be Li2B10F8-10, or Li2B12F10-12Z02.Z (for (A))=Cl or OR;X=H, F, Cl, Br, or OH;Z=H or Cl.Preferred Material: The nonreversibly oxidizable salt is lithium perchlorate, lithium hexafluorophosphate, lithium hexafluoroarsenate, lithium hexafluoroborate, lithium trifluoromethylsulfonate, lithium tetrafluoroborate, lithium tetrakis(pentafluorophenyl)borate, lithium bromide, lithium hexafluoroantimonate, LiN(SO2CF3)2, lithium bis(chelato)borates, lithium bis (dicarboxylic acid) borate, LiBF3C2F5 and/or LiPF3(CF2CF3)3. The salt that provides overcharge protection is Li2B12F12 Li2B12FxH12-x (x=10, 11 and/or 12), Li2B12FxCll2-x (x=6, 7, 8, 9, 10, 11 and/or 12), Li2B12Fx(OH)2x (x=10 and/or 11), Li2B12F10(OH)2, Li2B12F5H7 or Li2B10Cl10.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The electrolyte further comprises a nonreversibly oxidizable salt including lithium. The salt that provides overcharge protection is Li2Bl0H0-7Z3-10 (A), Li2Bl0Cl10, Li2B10H1-5Cl5-9, Li2Bl0Cl5-9(OR)1-5, Li2B10H2Cl8; Li2B10H0-7(OCH3)3-10, Li2B10C8(OH)2, Li2B10Br10, Li2B8Br8, Li2B12Cll2, or Li2B12I2. The salt that provides overcharge protection comprises a salt of formula Li2B10X10 or Li2B12Xl2. The salt can also be Li2B10F8-10, or Li2B12F10-12Z02.Z (for (A))=Cl or OR;X=H, F, Cl, Br, or OH;Z=H or Cl.Preferred Material: The nonreversibly oxidizable salt is lithium perchlorate, lithium hexafluorophosphate, lithium hexafluoroarsenate, lithium hexafluoroborate, lithium trifluoromethylsulfonate, lithium tetrafluoroborate, lithium tetrakis(pentafluorophenyl)borate, lithium bromide, lithium hexafluoroantimonate, LiN(SO2CF3)2, lithium bis(chelato)borates, lithium bis (dicarboxylic acid) borate, LiBF3C2F5 and/or LiPF3(CF2CF3)3. The salt that provides overcharge protection is Li2B12F12 Li2B12FxH12-x (x=10, 11 and/or 12), Li2B12FxCll2-x (x=6, 7, 8, 9, 10, 11 and/or 12), Li2B12Fx(OH)2x (x=10 and/or 11), Li2B12F10(OH)2, Li2B12F5H7 or Li2B10Cl10.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Material: The nonreversibly oxidizable salt can be LiB(C6H5)4 and/or LiN(SO2CF2CF3). The carrier is ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), dipropyl carbonate (DPC), bis(trifluoroethyl) carbonate, bis(pentafluoropropyl) carbonate, trifluoroethyl methyl carbonate, pentafluoroethyl methyl carbonate, heptafluoropropyl methyl carbonate, perfluorobutyl methyl carbonate, trifluoroethyl ethyl carbonate, pentafluoroethyl ethyl carbonate, heptafluoropropyl ethyl carbonate, perfluorobutyl ethyl carbonate, fluorinated oligomers, methyl propionate, butyl propionate, ethyl propionate, sulfolane, 1,2-dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 1,3-dioxolane, 4-methyl-1,3-dioxolane dimethoxyethane, triglyme, dimethylvinylene carbonate, vinylene carbonate (VC), vinylethylene carbonate (VEC), chloroethylene carbonate, tetraethyleneglycol, dimethyl ether, polyethylene glycols, sulfones, gamma-butyrolactone (GBL), methyl butyrate, ethyl butyrate, ethyl acetate, gamma-valerolactone, ethyl valerate, 2-methyl-tetrahydrofuran, 3-methyl-2-oxazolidinone, 1,3-dioxolane, 4-methyl-1,3-dioxolane, or 2-methyl-l,3-dioxolane. The salt that provides overcharge protection is a lithium fluoroborate from formulas Li2B10FxZ10-x or Li2B12FxZ12-x.x=greater than or equal to 3 for decaborate salt, or greater than or equal to 5 for dodecaborate salt;Z=H, Cl, Br, or OR;R=H, 1-8C alkyl, fluoroalkyl or aryl.Preferred Parameter: The lithium fluoroborate has a reversible oxidation potential of 0.1-2 volts above the voltage of the cell. Preferred Composition: The lithium fluoroborate salt is added at 3-70 wt.% of the total weight of the nonreversibly oxidizable salt and the salt that provides overcharge protection present in the cell. Preferred Method: The method further comprises changing the carrier to adjust the overcharge protection potential of the overcharge protection salt; and modifying the chemical substituents on the overcharge protection salt. Preferred Definition:    M=Li;    Q=closo-borate anion of formula (B8-12Z8-12)2-, closo-ammonioborate anion compositions of formula ((R'R"R'")NB8-12Z7-11) or closo-monocarborate anion compositions of formula (R""CB7-11Z7-11)1-;    Z=F, H, Cl, Br, or (OR);    R=H, (fluoro)alkyl or aryl;    N=bonded to B;    R',R",R'"=H, (cyclo)alkyl, aryl or polymer;    R""=bonded to C or can be H, (cyclo)alkyl, aryl, or polymer;    a=2.    EXAMPLE - A coin type cell battery composed of positive electrode, negative electrode, separator and electrolyte was prepared at room temperature. The positive electrode, consisted of LiCo0.8Ni0.15Al0.05O2 (positive electrode active material) 84 wt.%, carbon black (conducting agent) 4 wt.%, SFG-6 graphite (conducting agent) 4 wt.%, polyvinylidene fluoride (binder) 8 wt.% on an aluminum foil current collector. The negative electrode, consisted of MAG-10 graphite (anode active material) 92 wt.%, polyvinylidene fluoride (binder) 8 wt.% on a copper foil current collector. The separator was Celgard 3501, a microporous polypropylene film. The electrolyte was a 0.4 M solution of Li2B12F9H3 in 3:7 wt.% EC:DEC. The cell was charged by a constant current of 2 mA to a voltage of 4.1 V followed by a discharge current of 2 mA to 3 V. The cell was then overcharged by a constant current of 2 mA to a voltage greater than 4.1 V. A voltage plateau at approximately 4.5 V was observed. The Li2B12F9H3 overcharge protection salt was a mixture of Li2B12FxH12-x    x=6, 7, 8, 10, 11 or 12.