Abstract: A nickel-hydrogen secondary battery has a positive electrode including a positive electrode mixture which contains a nickel compound as a major component and which is supported on a collector sheet, a negative electrode including a negative electrode mixture which contains a hydrogen absorbing alloy as a major component, a binder and an electrically conductive material and which is supported on a collector sheet, the positive and negative electrodes being stacked up alternately or rolled up with a separator interposed therebetween to form an electrode group, and a battery case containing the electrode group together with an electrolyte, the battery case having an opening closed with a sealing plate which is provided with a positive electrode terminal, wherein the binder contains at least carboxylated styrene-butadiene copolymer latex, the conductive material contains metal flakes or short metal fibers, and an edge portion of the collector sheet of the negative electrode is electrically connected to the batter

Abstract: A rectangular nickel-metal hydride secondary cell permits improving the air-tightness and also permits preventing a metal case from being deformed in a step of folding an open end portion of the metal case. The rectangular nickel-metal hydride secondary cell, includes a rectangular cylindrical metal case having a bottom, an electrode group housed in the metal case, an alkali electrolyte contained in the metal case, a rectangular sealing plate mounted near the open end portion of the metal case. An insulating gasket is interposed in a compressed state between the inner wall near the open end of the metal case and the sealing plate. The metal case comprises a folded portion formed by inwardly folding the open end portion of the metal case and an inwardly projecting stepped portion formed along the inner surface of the metal case below the folded portion.

Abstract: A rectangular nickel-metal hydride secondary cell permits improving the air-tightness and-also permits preventing a metal case from being deformed in the step of folding an open end portion of the metal case.

Abstract: A rectangular nickel-metal hydride secondary cell permits improving the air-tightness and also permits preventing a metal case from being deformed in the step of folding an open end portion of the metal case.

Abstract: In order to replace acoustic lenses, frequency units corresponding to frequencies used by the acoustic lenses and housing transmitted pulse generating means, circulators and receiving means can be selected and the signal of a gate opening at a timing at which ultrasonic waves of a sample return can be selected.