TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Positive Electrode: The lithium cobalt oxide is LixCoO2 ( 0.4 less than x at most 1) and the lithium nickel cobalt oxide is LixNiyCo1-yO2 (0 less than y less than 0.5). The positive electrode comprises LiCoO2 and LiNi0.82Co0.18O2. The electrode comprises 25-75% of each oxide and further includes a conductive additive (3-10 wt.%) and/or a binder (1-5 wt.%).Preferred Conductive Additive: The conductive additive is acetylene black, carbon black, graphite or powdered nickel, aluminum, titanium or stainless steel (or their mixture).Preferred Negative Electrode: The negative electrode comprises a carbonaceous material (preferably coke, graphite, acetylene black, carbon black and/or glassy carbon) capable of intercalation or insertion of lithium. The electrode comprises 90-97 wt.% of carbonaceous material and 3-10 wt.% powdered fluoro-resin.Preferred Electrolyte: The non aqueous electrolyte comprises first solvent(s) selected from esters, ethers and dialkyl carbonates and second solvent(s) selected from cyclic carbonates, cyclic esters and cyclic amides. The first solvent is preferably tetrahydrofuran, methyl acetate, diglyme, triglyme, tetraglyme, 1,2-di(m)ethoxyethane, 1-ethoxy-2-methoxyethane, di(m)ethyl carbonate, dipropyl carbonate, ethyl methyl carbonate and/or (m)ethyl propyl carbonate. The second solvent is preferably propylene carbonate, ethylene carbonate, butylene carbonate, acetonitrile, dimethyl sulfoxide, dimethyl formamide, dimethyl acetamide, gamma-valerolactone, gamma-butyrolactone and/or N-methylpyrrolidinone. The electrolyte includes alkali metal salt(s) selected from LiPF6, LiBF4, LiAsF6, LiSbF6, LiClO4, LiAlCl4, LiGaCl4, LiNO3, LiC(SO2CF3)3, LiN(SO2CF3)2, LiSCN, LiO3SCF2CF3, LiC6F5SO3, LiO2CCF3, LiSO3F, LiB(C6H5)4 and LiCF3SO3.POLYMERSPreferred Binder: The binder is polytetrafluoroethylene, polyvinylidene fluoride, ethylene-tetrafluoroethylene, polyamide, polyimide or their mixture, preferably a fluoro-resin powder. EXAMPLE - The ability of a LiNi0.82Co0.18O2/LiCoO2 mixed cathode material to intercalate lithium was tested in cells activated with a non aqueous electrolyte. The two cathode constituents were blended together in weight ratios of 25:75 to 75:25. The blends were then mixed with 3% carbon black conductive additive and 6% poly(vinylidene fluoride) binder. The mixtures were added to N,N-dimethylformamide to form a slurry and then cast onto an aluminum foil substrate. After drying, the electrodes were pressed at 0.8 ton/cm2 pressure.    The cathode was separated from the anode by a polyethylene separator. Graphitic carbon coated on copper foil substrate was used as the anode material and placed against the separator facing the cathode. Both electrodes were configured into a spirally-wound cell design and placed in a cylindrical glass housing. The cells were activated with 1 M LiAsF6 dissolved in a 50:50 volume mixture of ethylene carbonate and dimethyl carbonate.    The cells were initially cycled in a low-rate discharge test. During the test, the cells were charged and discharged using a constant current of 20 mA (0.5 mA/cm2) between voltage limits of +2.75 V to +4.1 V vs Li/Li+. The cathode capacities for various ratios of constituents were as follows:    100% LiCoO2 110 mAh/g    75% LiCoO2/25% LiNi0.82Co0.18O2 132 mAh/g    50% LiCoO2/50% LiNi0.82Co0.18O2 132 mAh/g    25% LiCoO2/75% LiNi0.82Co0.18O2 144 mAh/g    100% LiNi0.82Co0.18O2 159 mAh/g.    The same cells were then subjected to high-rate discharge testing conducted by applying a constant current of 320 mA (8 mA/cm2) to a cutoff voltage of +2.75 V vs Li/Li+ to the cells. The delivered capacities were as follows:    100% LiCoO2 96 mAh/g    75% LiCoO2/25% LiNi0.82Co0.18O2 102 mAh/g    50% LiCoO2/50% LiNi0.82Co0.18O2 108 mAh/g    25% LiCoO2/75% LiNi0.82Co0.18O2 93 mAh/g    100% LiNi0.82Co0.18O2 92 mAh/g.