Abstract: A hermetically sealed battery is provided, equipped with a opening sealing unit 10 including a Positive Temperature Coefficient (PTC) element without reducing the volume of the outside can, and capable of preventing the generation of a large current in case a short circuit occurs as well as enhancing operational security. The opening sealing unit 10 according to the invention comprises a bottom plate 11 for closing the opening of the outside can 18, a positive electrode cap 12 forming a space for storing a pressure valve, said positive electrode cap being used as a terminal for the positive electrode, a resilient valve 14 having a steel plate 14a on the upper surface, a spring 15 and a PTC element ring 16 disposed on the flange 12a in the positive electrode cap 12. An insulation gasket 17 is mounted onto the periphery of the opening sealing unit 10 to hermetically close the opening of the outside can 18.

Abstract: A hermetically sealed battery with an opening-sealing unit 10 according to the present invention comprises a PTC element ring 16 elastically clamped between the flange 12a of a positive electrode cap 12 and a fold portion 11d formed at the peripheral portion 11c of a bottom plate 11, such that when the temperature of the PTC element rises due to overcurrent or overheating, the PTC element ring 16 can easily expand, thereby tripping the large current with its resistance capacity increased to a predetermined level at a predetermined temperature, thereby enhancing operational security of the battery.

Abstract: After coating a hydrogen absorbing alloy slurry obtained by kneading a hydrogen absorbing alloy powder 12a, a polyethylene oxide (PEO) powder as a binder 12b, and a suitable amount of water (a solvent for binder) to both surfaces of a metal core plate (active material holder) made of a punching metal, the core plate is dried. Then, after removing the active material layer 13 from the core plate 11 by a means such as cutting and the like, a definite amount of water (a solvent for binder) is sprayed to the cut surface (the exposed surface of the core plate 11) to attach the water to the cur surface followed by drying to provide a hydrogen absorbing alloy electrode 10, which is disposed at the outermost side of the electrode group.

Abstract: A hermetically sealed battery is provided, equipped with a opening sealing unit 10 including a Positive Temperature Coefficient (PTC) element without reducing the volume of the outside can, and capable of preventing the generation of a large current in case a short circuit occurs as well as enhancing operational security. The opening sealing unit 10 according to the invention comprises a bottom plate 11 for closing the opening of the outside can 18, a positive electrode cap 12 forming a space for storing a pressure valve, said positive electrode cap being used as a terminal for the positive electrode, a resilient valve 14 having a steel plate 14a on the upper surface, a spring 15 and a PTC element ring 16 disposed on the flange 12a in the positive electrode cap 12. An insulation gasket 17 is mounted onto the periphery of the opening sealing unit 10 to hermetically close the opening of the outside can 18.

Abstract: An alkaline storage battery includes a positive electrode active material containing nickel hydroxide as a main component. A part of the surface of the nickel hydroxide is unevenly covered with a cobalt compound having an average oxidation number of larger than +2 and containing alkaline cations. Since only a part of the surface of the nickel hydroxide is covered with the cobalt compound, the nickel hydroxide not covered with the cobalt compound is brought into direct contact with the electrolyte, thus improving the high rate discharging characteristic. Since a part of the surface of the nickel hydroxide is covered with the high-order cobalt compound containing alkaline cations, the high-order cobalt compound with high conductivity produces a highly conductive network within the positive electrode so that the rate of using the active material is improved.

Abstract: An alkaline storage battery comprising a positive electrode active material mainly composed of nickel hydroxide, characterized in that the nickel hydroxide is a higher order nickel hydroxide covered with a cobalt compound on the surface thereof or in the vicinity thereof and the higher order nickel hydroxide is provided with at least one compound selected from the group consisting of yttrium compound, erbium compound and ytterbium compound on the surface thereof or in the vicinity

Abstract: The invention provides a nickel-hydrogen storage battery which shows no deterioration of high rate discharge performance even after prolonged storage.

Abstract: After coating a hydrogen absorbing alloy slurry obtained by kneading a hydrogen absorbing alloy powder 12a, a polyethylene oxide (PEO) powder as a binder 12b, and a suitable amount of water (a solvent for binder) to both surfaces of a metal core plate (active material holder) made of a punching metal, the core plate is dried. Then, after removing the active material layer 13 from the core plate 11 by a means such as cutting and the like, a definite amount of water (a solvent for binder) is sprayed to the cut surface (the exposed surface of the core plate 11) to attach the water to the cur surface followed by drying to provide a hydrogen absorbing alloy electrode 10, which is disposed at the outermost side of the electrode group.

Abstract: A nickel-metal hydride storage cell is composed of a non-sintered positive electrode which is filled with a nickel active material whose particles are coated with cobalt compound layers of divalent or greater and a metal hydride electrode which is filled with a surface-treated hydrogen-absorbing alloy. In the cell, the positive electrode non-reactive capacity rate (represented by the Equation 1) and the negative electrode charge depth (represented by the Equation 2) after the initial charge/discharge are 16% or lower, and 80% or lower, respectively. This construction makes it possible to take larger actual cell capacity by setting the value of the negative electrode charge depth to the degree which causes no rise in the cell internal pressure, thereby expanding the capacity of the cell. positive electrode non-reactive capacity rate %=(positive electrode theoretical capacity−actual cell capacity)/positive electrode theoretical capacity×100  Eq.

Abstract: An alkaline storage battery includes a positive electrode active material containing nickel hydroxide as a main component. A part of the surface of the nickel hydroxide is unevenly covered with a cobalt compound having an average oxidation number of larger than +2 and containing alkaline cations. Since only a part of the surface of the nickel hydroxide is covered with the cobalt compound, the nickel hydroxide not covered with the cobalt compound is brought into direct contact with the electrolyte, thus improving the high rate discharging characteristic. Since a part of the surface of the nickel hydroxide is covered with the high-order cobalt compound containing alkaline cations, the high-order cobalt compound with high conductivity produces a highly conductive network within the positive electrode so that the rate of using the active material is improved.

Abstract: The battery has an electrode assembly with a first electrode plate and second electrode plate forming a positive electrode plate and negative electrode plate layered via a separator. An external case holds the electrode assembly, and a collector plate is electrically connected to the first electrode plate. The first electrode plate is a non-sintered type electrode with active material loaded into a porous metal material substrate, and has a connecting band of exposed substrate and an active material region. A protective tape is attached to at least one side of the connecting band of the first electrode plate. The connecting band is electrically connected to the collector plate. The second electrode plate projects out beyond the active material border of the connecting band and the active material region, and the active material border is opposite the second electrode plate with the separator in between the first electrode plate and the second electrode plate.

Abstract: A belt-shaped spongelike organic high polymer sheet is subjected to stretching forces in the longitudinal and lateral directions so as to transform the approximately spindle-shaped organic high polymer units which compose the organic high polymer sheet. After this, a metal is put into voids inside the organic high polymer sheet. Then, the organic high polymer is eliminated by baking it, and the metal is sintered. As a result, a spongelike metal substrate is completed whose carbon content is 0.5% by weight or less and whose metallic lattices have a longer length/shorter length ratio of 1.7 or below. The spongelike metal substrate is filled with electrode active material to form an electrode, which is combined with a counter electrode and a separator, and coiled in the direction of the longer lengths of the lattices to form a coiled electrode assembly. The electrode assembly is used to manufacture an alkali storage cell.

Abstract: A nickel hydroxide active material for use in an alkaline storage cell, the active material being essentially composed of nickel hydroxide particles covered with a cobalt compound adhered to their surfaces, wherein the cobalt compound is disordered in a crystal structure and formed in a higher order state containing alkali cation, and wherein the nickel hydroxide is in the form of a higher order nickel compound having an average oxidation value of 2.15 to 2.40.

Abstract: A nickel electrode for an alkaline storage cell manufactured by the steps of precipitating cobalt hydroxide on the surface of a first nickel active material essentially composed of nickel hydroxide, subjecting the first nickel active material to heat treatment under the presence of an alkaline solution and oxygen to that the cobalt hydroxide precipitated on the first nickel active material is disordered to its crystal structure and is formed in a higher order cobalt compound containing alkaline cation, and mixing the first nickel active material subjected to the alkali heat treatment with a second nickel hydroxide active material essentially composed of nickel hydroxide without forming any conductive substance of lower in dissolubility to the alkaline solution.

Abstract: A belt-shaped spongelike organic high polymer sheet is subjected to stretching forces in the longitudinal and lateral directions so as to transform the approximately spindle-shaped organic high polymer units which compose the organic high polymer sheet. After this, a metal is put into voids inside the organic high polymer sheet. Then, the organic high polymer is eliminated by baking it, and the metal is sintered. As a result, a spongelike metal substrate is completed whose carbon content is 0.5% by weight or less and whose metallic lattices have a longer length/shorter length ratio of 1.7 or below. The spongelike metal substrate is filled with electrode active material to form an electrode, which is combined with a counter electrode and a separator, and coiled in the direction of the longer lengths of the lattices to form a coiled electrode assembly. The electrode assembly is used to manufacture an alkali storage cell.

Abstract: In a method of manufacturing a nickel active material, nickel hydroxide particles coated with cobalt hydroxide are put on the mesh disk 4 of the fluidized granulator 1. Then, hot air is continuously supplied from outside through the hot air inlet 5, while air inside the fluidized granulator 5 is continuously emitted through the air outlet 8. At the same time, the nickel hydroxide particles are stirred with the stirring fan 3 and further dispersed by a hot air current. In this condition, an alkali aqueous solution is sprayed on the nickel hydroxide particles through the spray nozzle 7 by the pump 9. After the spray, the nickel hydroxide particles are further stirred in hot air so as to complete an alkali heat treatment.

Abstract: A nickel active material for an alkali storage cell whose surface is covered with a cobalt compound, wherein the diffusion and permeation into the nickel hydroxide mother particles of cobalt compound during excessive discharging, which act to reduce the active material efficiency and the excessive discharging characteristics, are prevented. This is achieved by having a covering layer, including one or more of the following metal compounds; an aluminum compound, a magnesium compound, an indium compound and a zinc compound, in addition to a cobalt compound, formed on the surface of a mother particle of nickel hydroxide, and by heat treating the covered mother particles in the presence of alkali and oxygen so as to convert the cobalt compound into a compound of cobalt where an oxidization number of cobalt is greater than 2.

Abstract: Fine-grained nickel electrode active material, each of which contributing to electrode reaction; production method of the fine-grained nickel electrode active material; and a nickel alkali storage cell of high capacity which is excellent in over discharge characteristics. In order to produce the fine-grained nickel electrode active material, fine-grained nickel hydroxide is precipitated by adding a given amount of alkali to solution in which at least a nickel compound is dissolved while the solution is stirred. Each of the fine-grained nickel hydroxide has pores with 20 vol % or more of a combined volume of the pores being composed of pores of diameter 60 .ANG. or greater. Next, a given amount of alkali is gradually added to suspension including the fine-grained nickel hydroxide and dissolved cobalt compound so that cobalt hydroxide is precipitated on the external surface of the fine-grained nickel hydroxide. The fine-grained nickel electrode active material is produced in the above mentioned way.

Abstract: A method for producing a hydrogen-absorbing alloy electrode including a step of treating the surface of a hydrogen-absorbing alloy. The surface treatment is applied to hydrogen-absorbing alloy having ununiform distortion of 3.5.times.10.sup.-3 or less by using only an acid solution whose pH value is between 0.5 and 3.5.

Abstract: A metal hydride electrode is mainly composed of a hydrogen-absorbing alloy and provided with carbon powder which is selected from acetylene black, carbon black, ketjen black, and active carbon. The metal hydride electrode is further provided with an additive including an oxide and/or a hydroxide of a metal having oxidation-reduction potential nobler than an operational potential of the hydrogen-absorbing alloy. The metal hydride electrode has excellent oxygen gas absorption ability and easy detection of -.DELTA.V, thereby realizing to produce a nickel-hydrogen alkaline storage cell with excellent charge/discharge cycle life.