Abstract: Heating reaction container comprises: a first member; a second member; and a third member. An opening is closed by the second member being detachably fitted in the first member and by the third member being detachably fitted in the second member. ?1, ?2, and ?3 satisfy a relation of ?3>?2>?1, ?3=?2>?1, or ?3>?2=?1, where ?1 represents a thermal expansion coefficient of a first material of the first member, ?2 represents a thermal expansion coefficient of a second material of the second member, and ?3 represents a thermal expansion coefficient of a third material of the third member. A gap is present before heating, and a space is sealed, through the heating, by a first contact surface coming into intimate contact with a second contact surface and by a third contact surface coming into intimate contact with a fourth contact surface.

Abstract: An object of the present invention or a problem to be solved by the present invention is to provide, as a material for use as a positive electrode of a sodium secondary battery, a novel material that allows the resulting battery to have capacity characteristics superior to those of conventional batteries. The composite metal oxide of the present invention has a composition represented by the general formula NaxMeyO2, where Me is at least one selected from the group consisting of Fe, Mn, and Ni, x satisfies 0.8<x?1.0, and y satisfies 0.95?y<1.05, and consists of a P2 structure. The sodium secondary battery of the present invention includes: a positive electrode (13) containing the composite metal oxide of the present invention; a negative electrode (16) containing a material capable of absorbing and desorbing Na ions; and an electrolyte containing Na ions and anions.

Abstract: The cathode active material for a nonaqueous electrolyte secondary battery according to an aspect of the present disclosure mainly comprises a compound represented by a composition formula: LixNay(Li?Na?Mn1-?-?)O2, where x, y, ?, and ? satisfy 0.75?x?1.0, 0<y?0.01, 0.75<x+y?1, 0.16???0.3, 0???0.01, and 0.2??+??0.3.

Abstract: To provide a positive electrode active material containing a pyrophosphate compound, ensuring that mixing of impurities is easily prevented to facilitate the synthesis and a high capacity battery is obtained, and a lithium ion battery using the positive electrode material. That is, the present invention relates to a pyrophosphate compound represented by the formula: Li2M1-xFexP2O7 (wherein M represents one or more elements selected from Mn, Zr, Mg, Co, Ni, V and Cu, and 0.3?x?0.9).

Abstract: A lithium ion secondary battery includes a positive electrode; a negative electrode; a separator disposed between the positive electrode and the negative electrode; and a non-aqueous electrolyte, wherein the positive electrode contains, as a positive electrode active material, a lithium-containing transition metal compound that belongs to space group Fd3-m and that contains lithium and transition metal M (M represents Mo, or Mo and at least one selected from the group consisting of Mn, Co, Ni, W, and V), a molar ratio of the lithium to the transition metal M is 2.7 or more and 3.3 or less, and a ratio of a mass of the lithium-containing transition metal compound to a total mass of the positive electrode active material in the positive electrode is 0.8 or more.

Abstract: To provide a positive electrode active material containing a pyrophosphate compound, ensuring that mixing of impurities is easily prevented to facilitate the synthesis and a high capacity battery is obtained, and a lithium ion battery using the positive electrode material. That is, the present invention relates to a pyrophosphate compound represented by the formula: Li2M1-xFexP2O7 (wherein M represents one or more elements selected from Mn, Zr, Mg, Co, Ni, V and Cu, and 0.3?x?0.9).