A secondary electrochemical cell includes a negative electrode including as an output conductor, a metallic or metal-coated open-pore form or a metallic or metal-coated nonwoven, as a carbon-based storage material that enables storage of electrical charge in the electrode through formation of an electrical double layer (Helmholtz double layer), activated carbon having a BET surface area of at least 800 m.sup.2/g, a non-carbon-based H2 storage material that can chemisorb hydrogen and/or store it as a metal hydride, a positive electrode including as an output conductor, a metallic or metal-coated open-pore form or a metallic or metal-coated nonwoven, and nickel hydroxide and/or nickel oxyhydroxide, a porous separator that separates the negative electrode and the positive electrode from one another, an aqueous alkaline electrolyte with which the electrodes and the separator are soaked, and a housing that encases the electrodes, the separator and the electrolyte.

A negative electrode active material includes a hydrogen storage alloy. The hydrogen storage alloy has an A.sub.2B.sub.7 crystal structure. The hydrogen storage alloy includes nickel. The saturation magnetization per unit mass is 1.9 emu.Math.g.sup.1 or more.

Provided are proton conducing rechargeable batteries that display excellent capacity. The rechargeable batteries include a cathode comprising a cathode electrochemically active material capable of storing and releasing hydrogen, optionally including Ni, and an anode, the anode including an anode electrochemically active material of one or more group 14 elements, the anode electrochemically active material in the powder form and associated by a binder, wherein a microstructure of the anode electrochemically active material is polycrystalline, a mixture of nanocrystalline and amorphous, or a combination of polycrystalline, nanocrystalline and amorphous. The cells include a non-aqueous electrolyte and are a characterized by a discharge capacity above 800 mAh/g of the anode electrochemically active material above 1 Volt.

A hydrogen storage alloy suitable for prescribed pretreatment, that is, pretreatment wherein mechanical pulverization is performed after pulverizing a hydrogen storage alloy and absorbing/desorbing hydrogen is provided. The hydrogen storage alloy comprises a parent phase having a CaCu.sub.5-type, that is, an AB.sub.5-type crystal structure, wherein the A site is constituted from a rare earth element containing La; and the B site does not contain Co and contains at least Ni, Al, and Mn, with the ratio (Mn/Al) of the content of Mn (molar ratio) to the content of Al (molar ratio) being 0.60 or more and less than 1.56, and the ratio (La/(Mn+Al)) of the content of La (molar ratio) to the total content of the content of Al (molar ratio) and the content of Mn (molar ratio) being more than 0.92.

A method of estimating life of a nickel-metal hydride battery that accommodates a positive electrode plate and a negative electrode plate facing the positive electrode plate with a separator therebetween and containing a hydrogen absorbing alloy together with an electrolyte is disclosed. A charge phase of charging the nickel-metal hydride battery and a discharge phase of discharging the nickel-metal hydride battery after the charge phase constitutes one cycle for charge/discharge of the nickel-metal hydride battery. The method includes: determining a rate of change after one charge/discharge cycle of a surface area of the negative electrode plate which is a boundary face in contact with the electrolyte, and determining an amount of corrosion of the hydrogen absorbing alloy based on the rate of change accumulated for n charge/discharge cycles to estimate the life of the nickel-metal hydride battery based on the amount of corrosion.

The present disclosure relates to improved processes for the preparation of metal hydrides. The present disclosure also relates to metal hydrides, e.g., metal hydrides prepared by the processes described herein, that exhibit enhanced hydrogen storage capacity when used as hydrogen storage systems.

A battery comprises an electrode group including a separator, a positive electrode and a negative electrode. The negative electrode comprises a negative electrode core, negative electrode mixture layers retained to the negative electrode core, and a fluorine resin layer disposed on the surface of the negative electrode mixture layers. The negative electrode mixture layers include a first outermost peripheral region located at the outermost periphery of the electrode group and a second outermost peripheral region located opposite to the first outermost peripheral region. When the amount of the fluorine resin constituting a first fluorine resin layer in a portion of the first outermost peripheral region is represented by A, and the amount of the fluorine resin constituting a second fluorine resin layer in a portion of the second outermost peripheral region is represented by B, a relation A>B is satisfied.

A carbothermic reduction method is provided for reducing a La-, Ce-, MM-, and/or Y-containing oxide in the presence of carbon and a source of a reactant element comprising Si, Ge, Sn, Pb, As, Sb, Bi, and/or P to form an intermediate alloy material including a majority of La, Ce, MM, and/or Y and a minor amount of the reactant element. The intermediate material is useful as a master alloy for in making negative electrode materials for a metal hydride battery, as hydrogen storage alloys, as master alloy additive for addition to a melt of commercial Mg and Al alloys, steels, cast irons, and superalloys; or in reducing Sm.sub.2O.sub.3 to Sm metal for use in SmCo permanent magnets.

The present disclosure relates to improved processes for the preparation of metal hydrides. The present disclosure also relates to metal hydrides, e.g., metal hydrides prepared by the processes described herein, that exhibit enhanced hydrogen storage capacity when used as hydrogen storage systems.

A nickel-hydrogen secondary battery includes an electrode group which contains a positive electrode, a negative electrode, and a separator, wherein the negative electrode includes a negative electrode core, and a negative electrode mixture layer held by the negative electrode core, wherein the negative electrode mixture layer contains a fluororesin; a quantity of the fluororesin, expressed by a mass applied per unit area of the negative electrode, is within a range of 0.2 mg/cm.sup.2 or more and 2.0 mg/cm.sup.2 or less; and a fluororesin content which is a ratio of the fluororesin contained in a unit volume of the negative electrode mixture layer is higher in an inner layer portion than in an outer layer portion in the negative electrode mixture layer.