Abstract: A solid electrolyte fuel cell plate structure includes a cell element layer composed of a solid electrolyte, an air electrode layer and a fuel electrode layer, a porous base body supporting the cell element layer, and a gas-impermeable member having electric conductivity. The cell element layer is arranged such that the solid electrolyte layer is sandwiched between the air electrode layer and the fuel electrode layer, with the air electrode layer or the fuel electrode layer being joined to the porous base body. The gas-impermeable member is associated with the solid electrolyte layer to allow gas internally passing through the porous base body to be separated from gas flowing outside the porous base body. Such a cell plate structure can be employed in a solid electrolyte fuel cell stack, which in turn can be employed in a solid electrolyte fuel cell electric power generation unit.

Abstract: A cell plate structure for a fuel cell is provided with a porous substrate, a lower electrode layer formed on the porous substrate, an upper electrode layer opposed to the lower electrode layer, a solid electrolyte layer having a layer element placed between the lower electrode layer and the upper electrode layer and composed of a plurality of divided electrolyte regions, a gas impermeable layer correspondingly covering an area where the solid electrolyte layer is absent on the porous substrate or on the lower electrode layer. The gas impermeable layer separates gas passing inside the porous substrate and gas passing outside the porous substrate. Such a cell plate structure is suited for use in a solid electrolyte type fuel cell.

Abstract: A single cell for a fuel cell in which an air electrode or a fuel electrode includes at least two layers. The air electrode includes an adhering cathode layer formed on one surface of the solid electrolyte layer and configured to show a function to allow the air electrode and the solid electrolyte layer to adhere electrically and mechanically to each other, and an electricity collecting cathode layer formed on the adhering cathode layer and configured to show an electricity collecting function of the air electrode. Alternatively, the fuel electrode includes an adhering anode layer formed on the other surface of the solid electrolyte layer and configured to show a function to allow the air electrode and the solid electrolyte layer to adhere electrically and mechanically to each other, and an electricity collecting anode layer formed on the adhering anode layer and configured to show an electricity collecting function.

Abstract: A rechargeable lithium ion battery with high power density comprises a positive electrode; a negative electrode; and a non-aqueous electrolytic solution, in which the positive electrode includes a active material layer containing a positive electrode active material with the particle diameter of 5 &mgr;m or less and having the thickness at a range of 20 to 80 &mgr;m. Another rechargeable lithium ion battery with high power density comprises a positive electrode; a negative electrode; and a non-aqueous electrolytic solution, in which the positive electrode has two active material layers, each of which contains a positive electrode active material with a different diameter and has the thickness at a range of 20 to 30 &mgr;m.

Abstract: A positive electrode active material for a nonaqueous electrolyte secondary battery includes at least a lithium-containing manganese layered composite oxide represented by the formula Li1−xAxMnO2, or the formula Li1−xAxMn1−yMyO2. The lithium-containing manganese composite oxide includes a lithium substitute metal A, such as Na, K, Ag, substituting for part of Li. The lithium substitution quantity x may be in the range of 0.03<x≦0.2.

Abstract: A positive electrode active material for a nonaqueous electrolyte secondary battery includes at least a lithium-deficient manganese layered composite oxide represented by the general formula Li1−xMnO2−&dgr;. A lithium deficiency quantity x is in the range of 0.03<x≦0.5. An oxygen nonstoichiometry quantity &dgr; is equal to or smaller than 0.2.

Abstract: A positive electrode active material for a nonaqueous electrolyte secondary battery includes at least a lithium-containing manganese layered composite oxide represented by the general formula Li1-xMn1-yMyO2-&dgr;. The lithium-containing manganese composite oxide is deficient in lithium with respect to the stoichiometric composition of a layered crystal structure represented by the general formula LiMeO2. Part of Mn is replaced by a substitute metal such as Co, Ni, Fe, Al, Ga, In, V, Nb, Ta, Ti, Zr, Ce or Cr.

Abstract: A positive electrode active material for a nonaqueous electrolyte secondary battery includes at least a lithium-containing manganese layered composite oxide represented by the general formula Li1−xMO2−y−&dgr;Fy. The second metallic element or constituent M may be Mn or a combination of Mn and substitute metal such as Co, Ni, Cr, Fe, Al, Ga or In. A lithium deficiency quantity x is in the range of 0<x<1. An oxygen defect quantity &dgr; may be equal to or smaller than 0.2. A quantity y of fluorine substituting for part of oxygen is greater than zero.