Abstract: A power storage cell comprises an electrode assembly, a cell case accommodating the electrode assembly, and an external terminal secured to an upper surface of the cell case. The external terminal has a terminal plate located above the cell case, and an insulating plate interposed between the cell case and the terminal plate. The insulating plate supports the terminal plate in such a manner that a gap is formed between the insulating plate and the terminal plate.

Abstract: A composite ceramic green sheet comprising: a first sheet portion comprising a first sheet material; a second sheet portion comprising a second sheet material, said second sheet portion differing in firing behavior from said first sheet portion; and a mixed portion provided between said first and second sheet portions, comprising a mixture of said first and second sheet materials, and having a width at least twice as large as a thickness of the composite ceramic green sheet, wherein said first and second sheet portions are integrated with each other thorough said mixed portion in a spread direction.

Abstract: A gas sensor element having an element body, the element body including: a ceramic heater having ceramic layers and a heater element embedded in the ceramic layers; and a solid electrolyte layer including a detection section covered by a pair of electrodes, the solid electrolyte layer being laminated together with the ceramic heater. Furthermore, the element body has a width at a front portion including the detection section smaller than at a rear portion, and at least both side edge faces of the front portion of the element body are covered with a porous layer.

Abstract: A prismatic ceramic heater for heating a gas sensor element includes a heating resistor embedded in ceramic, and has a substantially rectangular cross section. At least part of a longitudinally extending edge portion of the prismatic ceramic heater is located in the vicinity of the heating resistor. This part of the longitudinally extending edge portion is coated with a porous protective layer. The protective layer has a thickness not less than 20 ?m and a curved surface of a curvature radius not less than 10 ?m. The protective layer prevents cracking induced by contact with water.

Abstract: A gas sensor element having an element body, the element body including: a ceramic heater having ceramic layers and a heater element embedded in the ceramic layers; and a solid electrolyte layer including a detection section covered by a pair of electrodes, the solid electrolyte layer being laminated together with the ceramic heater. Furthermore, the element body has a width at a front portion including the detection section smaller than at a rear portion, and at least both side edge faces of the front portion of the element body are covered with a porous layer.

Abstract: A composite ceramic green sheet comprising: a first sheet portion comprising a first sheet material; a second sheet portion comprising a second sheet material, said second sheet portion differing in firing behavior from said first sheet portion; and a mixed portion provided between said first and second sheet portions, comprising a mixture of said first and second sheet materials, and having a width at least twice as large as a thickness of the composite ceramic green sheet, wherein said first and second sheet portions are integrated with each other thorough said mixed portion in a spread direction.

Abstract: A sensor element including an insulative base (11), a heating resistor (12), an oxygen pump cell (13), an oxygen detection cell (14), and a diffusion-chamber-forming member (161) having a rate-controlling introduction portion (163) and defining a diffusion chamber (16) in cooperation with electrodes (1321, 1421), wherein these components have been subjected to simultaneous firing (i.e., cofiring) to form a unitary sensor element. A partition wall (162), which extends from the diffusion-chamber-forming member and is made of alumina, is joined to a surface of a solid electrolyte (131) between two electrodes (1321, 1322) of an Ip cell. Preferably, a region within 20 ?m from the plane of junction joining the partition wall (162) to the solid electrolyte (131) contains no portion whose amount of non-alumina substances exceeds by 2% by mass (by weight) or more the amount of non-alumina substances of the diffusion-chamber-forming member (161).

Abstract: A multi-layer gas sensor element is described which comprises a solid electrolytic member, a substrate, and a porous member, wherein each of the substrate and the porous member has a thickness larger than that of the solid electrolytic member with respect to a lamination direction; the substrate and the porous member face each other and sandwich the solid electrolytic member; a ceramic component constituting the substrate in the highest volume percent is the same as the ceramic component constituting the porous member in the highest volume percent thereof; and the volume percent (R2) of the ceramic component contained in the porous member is 80% or more the volume percent (R1) of the ceramic component contained in the substrate.

Abstract: A sensor element including an insulative base (11), a heating resistor (12), an oxygen pump cell (13), an oxygen detection cell (14), and a diffusion-chamber-forming member (161) having a rate-controlling introduction portion (163) and defining a diffusion chamber (16) in cooperation with electrodes (1321, 1421), wherein these components have been subjected to simultaneous firing (i.e., cofiring) to form a unitary sensor element. A partition wall (162), which extends from the diffusion-chamber-forming member and is made of alumina, is joined to a surface of a solid electrolyte (131) between two electrodes (1321, 1322) of an Ip cell. Preferably, a region within 20 &mgr;m from the plane of junction joining the partition wall (162) to the solid electrolyte (131) contains no portion whose amount of non-alumina substances exceeds by 2% by mass (by weight) or more the amount of non-alumina substances of the diffusion-chamber-forming member (161).

Abstract: A prismatic ceramic heater for heating a gas sensor element includes a heating resistor embedded in ceramic, and has a substantially rectangular cross section. At least part of a longitudinally extending edge portion of the prismatic ceramic heater is located in the vicinity of the heating resistor. This part of the longitudinally extending edge portion is coated with a porous protective layer. The protective layer has a thickness not less than 20 &mgr;m and a curved surface of a curvature radius not less than 10 &mgr;m. The protective layer prevents cracking induced by contact with water.

Abstract: A multi-layer gas sensor element is described which comprises a solid electrolytic member, a substrate, and a porous member, wherein each of the substrate and the porous member has a thickness larger than that of the solid electrolytic member with respect to a lamination direction; the substrate and the porous member face each other and sandwich the solid electrolytic member; a ceramic component constituting the substrate in the highest volume percent is the same as the ceramic component constituting the porous member in the highest volume percent thereof; and the volume percent (R2) of the ceramic component contained in the porous member is 80% or more the volume percent (R1) of the ceramic component contained in the substrate.

Abstract: A gas sensor including a detection element having a front-end portion, a detection portion formed at the front-end portion of the detection element, and a protector that covers the detection portion. The protector includes a first portion having a first sidewall and a second portion having a second sidewall disposed outside the first portion. The first sidewall has an axial front end and a tapering portion. The tapering portion is formed from the axial front end of the first sidewall. The side portion has a front-end surface provided with a first gas outlet, and the second portion has a front-end surface provided with a second gas outlet. Furthermore, at least one gas inlet is formed to the sidewall of the second portion opposite the tapering portion, and plural gas inlets are formed on the sidewall of the first portion.