A method for fabricating an electrode for an energy storage device is provided. The method includes heating a mixture of solvent and materials for use as energy storage media; adding active material to the mixture; adding dispersant to the mixture to provide a slurry; coating a current collector with the slurry; and calendering the coating of slurry on the current collector to provide the electrode.

A method for fabricating an electrode for an energy storage device is provided. The method includes heating a mixture of solvent and materials for use as energy storage media; adding active material to the mixture; adding dispersant to the mixture to provide a slurry; coating a current collector with the slurry; and calendering the coating of slurry on the current collector to provide the electrode.

The present disclosure provides an irreversible additive contained in a cathode material for a secondary battery, wherein the irreversible additive is an oxide represented by the following chemical Formula 1, and wherein the oxide has a trigonal structure, a cathode material including the irreversible additive, and a secondary battery including the cathode material:

Li.sub.2+aNi.sub.1-bMo.sub.bO.sub.2+c  (1) in Formula 1, −0.2≤a≤0.2, 0<b≤0.2, 0≤c≤0.2.

The present disclosure provides an irreversible additive contained in a cathode material for a secondary battery, wherein the irreversible additive is an oxide represented by the following chemical Formula 1, and wherein the oxide has a trigonal structure, a cathode material including the irreversible additive, and a secondary battery including the cathode material:

Li.sub.2+aNi.sub.1-bMo.sub.bO.sub.2+c  (1) in Formula 1, −0.2≤a≤0.2, 0<b≤0.2, 0≤c≤0.2.

A layered-oxide positive electrode active material may have a molecular formula of Na.sub.xMn.sub.aFe.sub.bNi.sub.cM.sub.dN.sub.eO.sub.2-δQ.sub.f, where a doping element M is selected from at least one of Cu, Li, Ti, Zr, K, Sb, Nb, Mg, Ca, Mo, Zn, Cr, W, Bi, Sn, Ge, or Al, a doping element N is selected from at least one of Si, P, B, S, or Se, a doping element Q is selected from at least one of F, Cl, or N, 0.66≤x≤1, 0<a≤0.70, 0<b≤0.70, 0<c≤0.23, 0≤d<0.30, 0≤e≤0.30, 0≤f≤0.30, 0≤δ≤0.30, a+b+c+d+e=1, 0<e+f≤0.30, 0<(e+f)/a≤0.30, 0.20≤d+e+f≤0.30, and (b+c)/a≤1.5.

A layered-oxide positive electrode active material may have a molecular formula of Na.sub.xMn.sub.aFe.sub.bNi.sub.cM.sub.dN.sub.eO.sub.2-δQ.sub.f, where a doping element M is selected from at least one of Cu, Li, Ti, Zr, K, Sb, Nb, Mg, Ca, Mo, Zn, Cr, W, Bi, Sn, Ge, or Al, a doping element N is selected from at least one of Si, P, B, S, or Se, a doping element Q is selected from at least one of F, Cl, or N, 0.66≤x≤1, 0<a≤0.70, 0<b≤0.70, 0<c≤0.23, 0≤d<0.30, 0≤e≤0.30, 0≤f≤0.30, 0≤δ≤0.30, a+b+c+d+e=1, 0<e+f≤0.30, 0<(e+f)/a≤0.30, 0.20≤d+e+f≤0.30, and (b+c)/a≤1.5.

A positive-electrode material according to the present disclosure includes a positive-electrode active material and a coating layer covering the positive-electrode active material, wherein the coating layer contains oxygen and lithium, the positive-electrode active material and the coating layer constitute a coated active material, and the ratio Li/O of the lithium content to the oxygen content in a surface layer portion of the coated active material is 0.26 or less based on the atomic ratio.

A method of making a positive electrode includes forming a slurry of particles using an electrode formulation, a diluent, and oxalic acid, coating the slurry on a collector and drying the coating on the collector to form the positive electrode. The electrode formulation includes an electrode active material, a conductive carbon source, an organic polymeric binder, and a water soluble polymer. The diluent consists essentially of water.

A method of making a positive electrode includes forming a slurry of particles using an electrode formulation, a diluent, and oxalic acid, coating the slurry on a collector and drying the coating on the collector to form the positive electrode. The electrode formulation includes an electrode active material, a conductive carbon source, an organic polymeric binder, and a water soluble polymer. The diluent consists essentially of water.

Electrodes are formed with a porous layer of particulate electrode material bonded to each of the two major sides of a compatible metal current collector. In one embodiment, opposing electrodes are formed with like lithium-ion battery anode materials or like cathode materials or capacitor materials on both sides of the current collector. In another embodiment, a battery electrode material is applied to one side of a current collector and capacitor material is applied to the other side. In general, the electrodes are formed by combining a suitable grouping of capacitor layers with un-equal numbers of anode and cathode battery layers. One or more pairs of opposing electrodes are assembled to provide a combination of battery and capacitor energy and power properties in a hybrid electrochemical cell. The cells may be formed by stacking or winding rolls of the opposing electrodes with interposed separators.