Abstract: The invention provides a positive electrode active material for sodium batteries which has a high working potential and can be charged and discharged at a high potential. The invention also provides a method of producing such a positive electrode active material, with this positive electrode active material for sodium batteries being represented by general formula (1) below: NaxMy(AO4)z(P2O7)w??(1) (wherein M is at least one selected from the group consisting of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper and zinc; A is at least one selected from the group consisting of aluminum, silicon, phosphorus, sulfur, titanium, vanadium and tungsten; x satisfies the condition 4?x?2; y satisfies the condition 4?y?1, z satisfies the condition 4?z?0; w satisfies the condition 1?w?0; and one or both of z and w is 1 or more).

Abstract: The invention is to provide a positive electrode material for sodium batteries, which has high operating potential and enable charging and discharging at high potential, and a method for producing thereof. Disclosed is a positive electrode material for sodium batteries, comprising positive electrode active material particles represented by the following general formula (1), and an electroconductive carbonaceous material that coats at least part of the surface of the positive electrode active material particles: General Formula (1): NaxMy(AO4)z(P2O7)w wherein M is at least one selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn; A is at least one selected from the group consisting of Al, Si, P, S, Ti, V and W; x is a value that satisfies 4?x?2; y is a value that satisfies 4?y?1; z is a value that satisfies 4?x?0; w is a value that satisfies 1?w?0; and at least one of z and w is 1 or more.

Abstract: A cathode active material for sodium batteries has excellent discharge capacity, and a sodium battery has the cathode active material for sodium batteries. A cathode active material for sodium batteries is represented by a general formula Na4CO(3-x)Mx(PO4)2P2O7; M is any of Fe, Cr, Mn and Al; X is 0.015?x?0.21 when M is Fe; X is 0.03?x?0.18 when M is Cr; X is 0.006?x?0.24 when M is Mn; and X is 0.03?x?0.06 when M is Al.

Abstract: A main object of the present invention is to provide an anode active material capable of increasing energy density at the same time increasing battery safety, and a metal ion battery prepared with the anode active material. The present invention is an anode active material including an element that belongs to alunite group capable to insert and remove an ion(s) of at least one metal element selected from the group consisting of alkali metal elements and alkaline-earth metal elements, and a metal ion battery having a cathode, an anode, and an electrolyte filled between the cathode and the anode, the electrolyte conducting a metal ion(s), wherein the anode active material is contained in the anode.

Abstract: The main object of the present invention is to provide a cathode active material which is used for a hybrid ion battery of Li ions and Na ions, and operates at a high potential. The present invention solves the problem by providing a cathode active material used for a hybrid ion battery of Li ions and Na ions, comprising an Na4M3(PO4)2P2O7 crystal phase (M is at least one kind of Ni, Co, Mn, Fe, V, Cr, Cu and Zn).

Abstract: The invention is to provide a positive electrode material for sodium batteries, which has high operating potential and enable charging and discharging at high potential, and a method for producing thereof. Disclosed is a positive electrode material for sodium batteries, comprising positive electrode active material particles represented by the following general formula (1), and an electroconductive carbonaceous material that coats at least part of the surface of the positive electrode active material particles: General Formula (1): NaxMy(AO4)z(P2O7)w wherein M is at least one selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn; A is at least one selected from the group consisting of Al, Si, P, S, Ti, V and W; x is a value that satisfies 4?x?2; y is a value that satisfies 4?y?1; z is a value that satisfies 4?x?0; w is a value that satisfies 1?w?0; and at least one of z and w is 1 or more.

Abstract: This invention provides a secondary battery that comprises a positive electrode comprising a positive electrode active material, a negative electrode comprising a negative electrode active material, and a non-aqueous electrolyte comprising a supporting salt. The positive electrode active material is a manganese phosphate compound represented by the next general formula: NaxMnPO4F. Herein, x satisfies 2.02<x?2.50. Mn may be partially substituted with one, two or more species of metal selected from Al, Mg and Ti.

Abstract: A main object of the present invention is to provide an anode active material capable of increasing energy density at the same time increasing battery safety, and a metal ion battery prepared with the anode active material. The present invention is an anode active material including an element that belongs to alunite group capable to insert and remove an ion(s) of at least one metal element selected from the group consisting of alkali metal elements and alkaline-earth metal elements, and a metal ion battery having a cathode, an anode, and an electrolyte filled between the cathode and the anode, the electrolyte conducting a metal ion(s), wherein the anode active material is contained in the anode.

Abstract: The invention provides a positive electrode active material for sodium batteries which has a high working potential and can be charged and discharged at a high potential. The invention also provides a method of producing such a positive electrode active material, with this positive electrode active material for sodium batteries being represented by general formula (1) below: NaxMy(AO4)z(P2O7)w??(1) (wherein M is at least one selected from the group consisting of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper and zinc; A is at least one selected from the group consisting of aluminum, silicon, phosphorus, sulfur, titanium, vanadium and tungsten; x satisfies the condition 4?x?2; y satisfies the condition 4?y?1, z satisfies the condition 4?z?0; w satisfies the condition 1?w?0; and one or both of z and w is 1 or more).