Abstract: There is provided an assembled battery allowed to compute and detect an SOC easily with high accuracy while increasing energy density. An assembled battery 1 is configured by connecting batteries BT1 to BTn-1 and a battery BTn in series. A discharge curve of each of the batteries BT1 to BTn-1 exhibits substantially flat characteristics, and a discharge curve of the battery BTn exhibits slope characteristics. The SOC or DOD of the assembled battery 1 is detected from the battery voltage of the battery BTn by a battery control unit 3. As the discharge curve of the battery BTn exhibits slope characteristics, the battery voltage is allowed to be detected easily with high accuracy. As the batteries BT1 to BTn-1 have high energy density, the energy density of the whole assembled battery 1 is allowed to be increased, and the size and weight of the assembled battery 1 are allowed to be reduced.

Abstract: A battery pack includes a plurality of batteries, each including a battery element formed by winding or stacking a positive electrode and a negative electrode with a separator therebetween, and a packaging material packaging the battery element; a connecting member that electrically connects the batteries to form a battery group; a holding unit that holds the batteries together; a protection circuit substrate connected to the battery group; and an outer packaging member that integrally covers the battery group and the protection circuit substrate, the outer packaging member being formed by filling a space in a molding die housing the battery group and the protection circuit substrate with a resin and curing the resin at a temperature of 100° C. or less.

Abstract: A method of producing an oxygen sensing element which is essentially an oxygen concentration cell in the form of a lamination of relatively thin layers. The first step of the method is to prepare a lamination of a ceramic shield layer, an inner or reference electrode layer, a solid electrolyte layer and an outer or measurement electrode layer which is formed by sintering metal particles applied to the solid electrolyte layer surface in the form of a paste or slurry and dried. Then an additional measurement electrode layer, preferably not thicker than 1.0 micron, is formed on the outer surface of the sintered measurement electrode layer by a physical vapor deposition technique such as ion plating, sputtering or vacuum evaporation. Preferably this electrode layer is formed by a two-stage vapor deposition process wherein the first stage deposition is terminated before the deposited layer becomes thicker than 0.5 microns.