A method of producing electrodes includes selecting a palladium alloy, annealing the palladium alloy at a first temperature above 350° C., cold working the palladium alloy into a desired electrode shape, and annealing the palladium alloy at a second temperatures and for a time sufficient to produce a grain size between about 5 microns and about 100 microns. The method further includes etching the palladium alloy, rinsing the palladium alloy with at least one of water and heavy water, and storing the palladium alloy in an inert environment.

A high-capacity and long-life negative electrode hydrogen storage material of La—Mg—Ni type for secondary rechargeable nickel-metal hydride battery and a method for preparing the same are provided in the present invention. A chemical formula of the negative electrode hydrogen storage material of La—Mg—Ni type is La.sub.1-x-yRe.sub.xMg.sub.y(Ni.sub.1-a-bAl.sub.aM.sub.b).sub.z, wherein Re is at least one of Ce, Pr, Nd, Sm, Y, and M is at least one of Ti, Cr, Mo, Nb, Ga, V, Si, Zn, Sn; 0≤x≤0.10, 0.3≤y≤0.5, 0<a≤0.05, 0≤b≤0.02, 2.3≤z<3.0. The negative electrode hydrogen storage material of La—Mg—Ni type in the present invention has excellent charge-discharge capacity and cycle life. The negative electrode hydrogen storage material of La—Mg—Ni type can be applied in both common secondary rechargeable nickel-metal hydride battery and secondary rechargeable nickel-metal hydride battery with ultra-low self-discharge and long-term storage performance.

Electrodes for a metal-hydrogen battery are described. The electrodes include one or more porous layers, each of the porous layers including a porous substrate and a catalyst layer covering the porous substrate, the catalyst layer including a transition metal, wherein at least one of the at least one porous layer includes a surface with features that facilitate hydrogen gas transport. In some embodiments, an anode electrode includes a first porous layer having a first surface; and a second porous layer adjacent the first porous layer having a second surface, wherein the first surface of the first porous layer and the second surface of the second porous layer form hydrogen gas transport channels.

Systems, methods, and devices of various aspects include using tin and/or antimony as an additive to an electrolyte and/or electrode in an electrochemical system, such as a battery, having an iron-based anode. In some aspects, the addition of tin and/or antimony may improve cycling of the iron-based anode. Systems, methods, and devices of various aspects include using high hydroxide concentration electrolyte in an electrochemical system, such as a battery. In some aspects, a high hydroxide concentration electrolyte may increase the stored amount of charge stored in the cell (i.e., the capacity of the battery material) and/or decrease the overpotential (i.e., increase the voltage) of the battery.

An air electrode catalyst for an air secondary battery includes a pyrochlore-type composite oxide having two or more crystal structures having a different amount of oxygen. A battery, according to some embodiments, includes an electrode group including an air electrode and a negative electrode stacked with a separator therebetween, and a container accommodating the electrode group along with an alkali electrolyte solution, wherein the air electrode includes the air electrode catalyst. The air electrode catalyst may have a pyrochlore-type composite oxide having a crystal structure represented by Bi.sub.2Ru.sub.2O.sub.6.92 and a crystal structure represented by Bi.sub.2Ru.sub.2O.sub.7.33.

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.

There is provided a plate for a battery stack including: a plate-shaped terminal to which an electric wire is connected; and a plate-shaped housing having an accommodating recess where the terminal is accommodated. The accommodating recess includes a retaining hole, and the terminal includes a connection portion that is electrically connected to a counterpart member, and a retaining piece that is inserted into the retaining hole and locked to the retaining hole.

A hydrogen storage alloy suitable for a negative electrode of an alkaline storage battery is provided. The hydrogen storage alloy provided is a hydrogen storage alloy used for an alkaline storage battery that has, as a main phase, one or two crystal structures selected from an A.sub.2B.sub.7-type structure and an AB.sub.3-type structure, and that is represented by a general formula: (La.sub.1-a-bCe.sub.aSm.sub.b).sub.1-cMg.sub.cNi.sub.dAl.sub.eCr.sub.f (where suffixes a, b, c, d, e, and f in this formula (1) meet the following conditions: 0<a≤0.15; 0≤b≤0.15; 0.17≤c≤0.32; 0.02≤e≤0.10; 0≤f≤0.05; and 2.95≤d+e+f≤3.50.

A main object of the present disclosure is to provide an anode active material with excellent capacity properties. The present disclosure achieves the object by providing an anode active material to be used in an alkaline storage battery, the anode active material including: a base material containing Ti and Cr, and including a BCC structure as a metastable phase; and a coating layer that coats the base material, and contains a catalyst metal and a metal with oxygen affinity that is more than oxygen affinity of Ti; wherein an oxide film is present in an interface between the coating layer and the base material; and when a first thickness T.sub.A (nm) and a second thickness T.sub.B(nm) of the oxide film are determined by Auger electron spectroscopy, a rate of the T.sub.A with respect to the T.sub.B, which is T.sub.A/T.sub.B is, for example, 1.50 or more.

An ABs-type hydrogen storage alloy is provided that has a low Co amount and uses Mm composed of La and Ce, which is capable of preventing a decrease in lifetime characteristics. The hydrogen storage alloy has an ABx composition constituted with an A-site composed of an Mm and a B-site composed of Ni, Co, Mn, and Al, or Ni, Mn, and Al, wherein Mm is composed of La and Ce; the molar ratio of Co is 0.0 or more and 0.11 or less when the molar ratio of Mm is 1.00; the ratio (Al/Mn) of the molar ratio of Al to the molar ratio of Mn is 0.35 to 1.10; and the ratio of the c-axis length to the a-axis length in the CaCu.sub.5-type crystal structure is 0.8092 or more.