Laves phase-related BCC metal hydride alloys historically have limited electrochemical capabilities. Provided are processes of activating these alloys to produce hydrogen storage materials with greater than 200 mAh/g capacities and commonly much greater than 300 mAh/g capacities. The processes include cooling the alloy during hydrogenation to reduced temperatures or by subjecting the materials to significantly increased hydrogen pressures. Temperatures in many embodiments do not exceed 300° C. By decreasing the temperature or increasing the hydrogen pressure the phase structure of the material is optimized to increase a synergistic effect between multiple phases in the resulting alloy thereby greatly improving the electrochemical capacities.

An electrochemical direct heat to electricity converter includes a primary thermal energy source; a working fluid; an electrochemical cell comprising at least one membrane electrode assembly including a first porous electrode, a second porous electrode and at least one membrane, wherein the at least one membrane is sandwiched between the first and second porous electrodes and is a conductor of ions of the working fluid; an energy storage reservoir; and an external load. The electrochemical cell operates on heat to produce electricity. When thermal energy available from the primary thermal energy source is greater than necessary to meet demands of the external load, excess energy is stored in the energy storage reservoir, and when the thermal energy available from the primary thermal energy source is insufficient to meet the demands of the external load, at least a portion of the excess energy stored in the energy storage reservoir is used to supply power to the external load.

A negative electrode used in a nickel metal hydride secondary battery includes a negative electrode core body and a negative electrode mixture carried on the negative electrode core body. The negative electrode mixture includes hydrogen storage alloy powder which is an aggregate of hydrogen storage alloy particles, a binder, and a thickener. The hydrogen storage alloy particles have a volume mean particle size of 40 μm or less and a concentration of chlorine of not less than 180 ppm to not more than 780 ppm.

A battery includes an electrode group including an air electrode and a negative electrode stacked with a separator therebetween, and a battery case accommodating the electrode group along with an alkali electrolyte solution, wherein the air electrode includes an air electrode mixture containing a pyrochlore-type composite oxide and a manganese oxide, and the pyrochlore-type composite oxide is a bismuth-ruthenium oxide.

A negative electrode for a rechargeable lithium battery and a rechargeable lithium battery including the same. The negative electrode includes: a current collector; a first negative active material layer disposed on one side of the current collector and including a first negative active material and a linear conductive material; and a second negative active material layer disposed on one side of the first negative active material layer and including a second negative active material.

Provided is a core/shell composite that includes a core portion containing a heat resistant material selected from an inorganic oxide, a ceramic, a mineral and the like and having rigidity, and at least one layer of shell portion containing a hydrogen absorbing/desorbing metal covering the entire or a part of the core portion. The heat resistant material contained in the core portion has a melting point higher than the highest melting point among the hydrogen absorbing/desorbing metal contained in the shell portion. In a method for producing the core/shell composite, the core portion is covered with the shell portion by deposition in the absence of oxygen.

A battery includes an electrode group including an air electrode and a negative electrode stacked with a separator therebetween, and an accommodating bag accommodating the electrode group along with an alkali electrolyte solution. The air electrode includes a catalyst for an air secondary battery. This catalyst for an air secondary battery is produced by a method for producing a catalyst for an air secondary battery, the method including a precursor preparation step of preparing a bismuth-ruthenium oxide precursor, a calcination step of calcining the bismuth-ruthenium oxide precursor obtained in this precursor preparation step to form a bismuth-ruthenium oxide, and a nitric acid treatment step of immersing the bismuth-ruthenium oxide obtained by this calcination step in a nitric acid aqueous solution.

A battery system includes a nickel hydride battery and an electronic control unit. The electronic control unit is configured to store data indicating a corresponding relationship between an elapsed time from start of use of the nickel hydride battery and a memory quantity. The data are data determined in a classified manner individually for each of conditions of use that are defined in such a manner as to include an open circuit voltage and a temperature. The electronic control unit is configured to sequentially calculate, with reference to the data, the memory quantity within a time when classification of the conditions of use does not change. The memory quantity is a quantity indicating an amount of change in voltage resulting from a memory effect. The electronic control unit is configured to estimate a current memory quantity of the nickel hydride battery by integrating the calculated memory quantity.

An electrochemical cell includes a first hydrogen-rich zone including a cathode, a second hydrogen-poor zone including an anode, an electrical component, and a sorbent configured to capture hydrogen in the second zone and release hydrogen protons into the first zone, an electrolyte located between the cathode and the sorbent, and an electrical circuit arranged to apply voltage bias to remove the captured hydrogen from the sorbent.

A nickel-metal hydride secondary battery includes an outer can and a group of electrodes housed in the outer can together with an alkaline electrolytic solution. The group of electrodes includes a positive electrode and a negative electrode that are superposed with a separator interposed therebetween, and the negative electrode includes a hydrogen absorbing alloy for nickel-metal hydride secondary batteries, the hydrogen absorbing alloy having a single composition and composed of a plurality of crystal phases.