An alkaline battery has a positive electrode mixture containing manganese dioxide and a conductive material filling a tubular positive electrode can that is closed at one end. A negative electrode mixture containing a zinc powder filling on an inner peripheral side of a separator is disposed on an inside of the positive electrode mixture. The negative electrode mixture contains zinc particles with a granularity of 75 μm or less at 25 to 40 mass %. The positive electrode mixture has a plurality of tubular pellets stacked inside the positive electrode can coaxially with the positive electrode can. A sum s of lengths of gaps between the pellets is set at 1 to 14% with respect to a sum d of lengths of the pellets. Thus, a sufficient amount of the electrolyte is held in the gaps and between the pellets in the positive electrode.

Low-cost electrochemical energy storage devices having electrochemical cells containing zinc electrodes in aqueous electrolytes, which exhibit superior cycle performance, preferably comprise the following elements: (a) a cathode formed of manganese dioxide particles, preferably doped with at least one of magnesium, strontium, barium, calcium, and lanthanum, wherein the manganese dioxide particles preferably form at least one of (1) a delta manganese dioxide structure and (2) a todokorite manganese dioxide structure; (b) an anode formed of particles comprising zinc, wherein the particles are preferably treated with at least one of bismuth, indium, gallium, antimony, and tin; (c) a mixed ion electrolyte solution with a pH greater than or equal to three and less than or equal to seven, wherein the solution preferably comprises at least one monovalent salt and at least one divalent salt; and (d) a mesh as cathode current collector comprising at least one of titanium, stainless steel, tantalum, and niobium, wherein the mesh is preferably coated by an electrically conductive and yet oxidation resistant material comprising but not limited to carbon.

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 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.

An electrochemical battery cell comprising an anode having a primary anode active material, a cathode, and an ion-conducting electrolyte, wherein the cell has an initial output voltage, Vi, measured at 10% depth of discharge (DoD), selected from a range from 0.3 volts to 0.8 volts, and a final output voltage Vf measured at a DoD no greater than 90%, wherein a voltage variation, (Vi−Vf)/Vi, is no greater than ±10% and the specific capacity between Vi and Vf is no less than 100 mAh/g or 200 mAh/cm.sup.3 based on the cathode active material weight or volume, and wherein the primary anode active material is selected from lithium (Li), sodium (Na), potassium (K), magnesium (Mg), aluminum (Al), zinc (Zn), titanium (Ti), manganese (Mn), iron (Fe), vanadium (V), cobalt (Co), nickel (Ni), a mixture thereof, an alloy thereof, or a combination thereof.

A lithium ion battery includes a cathode having a composite cathode active material and an anode having an anode active material. The composite cathode active material includes at least one first and one second cathode active material, wherein the second cathode active material is a compound having a spinel structure and wherein at least a lithiation degree of the first cathode active material differs from a lithiation degree of the second cathode active material. A degree of lithiation a of the first cathode active material is higher than a degree of lithiation b of the second cathode active material before electrolyte filling and before the first discharging and/or charging process of the lithium ion battery. The anode active material is pre-lithiated before the electrolyte filling and the first discharging and/or charging process of the lithium ion battery. A method for producing such a lithium ion battery is also described.

Preparation, characterization, and an electrochemical study of Mg.sub.0.1V.sub.2O.sub.5 prepared by a novel sol-gel method with no high-temperature post-processing are disclosed. Cyclic voltammetry showed the material to be quasi-reversible, with improved kinetics in an acetonitrile-, relative to a carbonate-, based electrolyte. Galvanostatic test data under a C/10 discharge showed a delivered capacity >250 mAh/g over several cycles. Based on these results, a magnesium anode battery, as disclosed, would yield an average operating voltage ˜3.2 Volts with an energy density ˜800 mWh/g for the cathode material, making the newly synthesized material a viable cathode material for secondary magnesium batteries.

Preparation, characterization, and an electrochemical study of Mg.sub.0.1V.sub.2O.sub.5 prepared by a novel sol-gel method with no high-temperature post-processing are disclosed. Cyclic voltammetry showed the material to be quasi-reversible, with improved kinetics in an acetonitrile-, relative to a carbonate-, based electrolyte. Galvanostatic test data under a C/10 discharge showed a delivered capacity >250 mAh/g over several cycles. Based on these results, a magnesium anode battery, as disclosed, would yield an average operating voltage ˜3.2 Volts with an energy density ˜800 mWh/g for the cathode material, making the newly synthesized material a viable cathode material for secondary magnesium batteries.

The present application relates to a battery module, comprising a first type of battery cells and a second type of battery cells electrically connected at least in series, wherein the first type of battery cells and the second type of battery cells are battery cells with different chemical systems, the first type of battery cells comprises N first battery cells, the second type of battery cells comprises M second battery cells, N and M are positive integers, the first battery cell comprises a first separator and a first electrolyte, the second battery cell comprises a second separator and a second electrolyte, a kinetic characteristic factor x1 of the first battery cell is: x1=1000×(ε1×r1)/(τ1×t1×θ1), a kinetic characteristic factor x2 of the second battery cell is: x2=1000×(ε2×r2)/(τ2×t2×θ2), and x1 and x2 satisfy: 0.01≤x1/x2≤160.