Abstract: A positive electrode (11) according to one embodiment is provided with: a positive electrode collector (30); a first middle layer (32) disposed on one of two surfaces of the positive electrode collector (30), the surface being on the inner circumferential side when the positive electrode collector (30) is wound; a second middle layer (34) that is disposed on the other surface that is on the outer circumferential side; and a positive electrode mixed material layer (36) disposed on the first middle layer (32) and on the second middle layer (34). The first middle layer (32) and the second middle layer (34) contain insulating particles and an electrical conductor, and the thickness of the first middle layer (32) is less than the thickness of the second middle layer (34).

Abstract: This lithium ion secondary battery comprises a negative electrode, a positive electrode, a non-aqueous electrolyte including a lithium salt, and an aqueous electrolyte including a lithium salt, wherein: among the negative electrode and the positive electrode, the aqueous electrolyte contacts only the positive electrode; among the negative electrode and the positive electrode, the non-aqueous electrolyte contacts at least the negative electrode; the positive electrode contains a positive electrode active material; the positive electrode active material contains a lithium transition metal composite oxide and a surface modification layer formed on the surface of primary particles of the lithium transition metal composite oxide; and the surface modification layer contains an alkali earth metal element.

Abstract: An electrode group includes a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a positive electrode lead electrically connected to the positive electrode. The positive electrode includes a positive electrode current collector and a positive electrode active material layer carried on each main surface of the positive electrode current collector. The positive electrode current collector has an exposed section that does not carry the positive electrode active material layer. The negative electrode includes a negative electrode current collector and a negative electrode active material layer carried on each main surface of the negative electrode current collector and has a first region and a second region. The mass of the negative electrode active material layer in the first region per unit area is smaller than the mass of the negative electrode active material layer in the second region per unit area.

Abstract: This positive electrode includes: a positive electrode current collector; a positive electrode mixed material layer that is formed on at least one surface of the positive electrode current collector; and a protective layer which includes an insulating inorganic compound and a conductive material, and is interposed between the positive electrode current collector and the positive electrode mixed material layer. The protective layer includes secondary particles comprising agglomerated primary particles of the inorganic compound. The median value of the particle size of the secondary particles is 30 ?m or less.

Abstract: An electrode group includes a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a positive electrode lead electrically connected to the positive electrode. The positive electrode includes a positive electrode current collector and a positive electrode active material layer carried on each main surface of the positive electrode current collector. The positive electrode current collector has an exposed section that does not carry the positive electrode active material layer. The negative electrode includes a negative electrode current collector and a negative electrode active material layer carried on each main surface of the negative electrode current collector and has a first region and a second region. The mass of the negative electrode active material layer in the first region per unit area is smaller than the mass of the negative electrode active material layer in the second region per unit area.

Abstract: This secondary battery positive electrode is provided with a positive-electrode current collector, a positive-electrode mixture layer, and an intermediate layer disposed between the positive-electrode current collector and the positive-electrode mixture layer. The intermediate layer comprises: a first intermediate layer that includes a non-oxide conductive inorganic compound and a positive-electrode active material; and a second intermediate layer that includes an insulating inorganic material and a non-oxide conductive inorganic compound. The conductive inorganic compound becomes an insulating oxide at 300° C. or above.

Abstract: A secondary battery includes an electrode assembly including a positive electrode, a negative electrode, a first separator disposed on one side of the surface of the negative electrode and having a thickness T1, and a second separator disposed on the other side of the surface of the negative electrode and having a thickness T2. The thickness T2 of the second separator is larger than the thickness T1 of the first separator. The first separator includes a first porous film having a porosity P1, and the second separator includes a second porous film having a porosity P2. At least one of the first separator and the second separator includes a heat resistant layer. The positive electrode, the first separator, the negative electrode and the second separator are wound together such that the first separator is arranged on the outer side and the second separator is arranged on the inner side.

Abstract: A positive electrode used in a secondary cell that is an example of the present embodiment is provided with a positive electrode collector, an intermediate layer formed on the positive electrode collector, and a positive electrode mixture layer formed on the intermediate layer. The positive electrode mixture layer has a thermally expandable material and a positive electrode active material. The thermally expandable material content of the positive electrode mixture layer is at least 0.1% by mass and less than 5% by mass. The intermediate layer has an insulating inorganic material and a conductive agent. The insulating inorganic material content of the intermediate layer is 80-99% by mass.

Abstract: A secondary battery positive electrode is provided with: a positive electrode current collector; a positive electrode mixture layer; and an intermediate layer disposed between the positive electrode current collector and the positive electrode mixture layer. The intermediate layer comprises first particles configured from an electrically conductive material, and second particles which are configured from an insulating inorganic material and have an average grain size greater than an average grain size of the first particles. The volume ratio of the first particles in the intermediate layer is not less than 25% and less than 70%. The volume ratio of the second particles in the intermediate layer is not less than 30% and less than 75%. The density of the intermediate layer is greater than 1 g/cm3 and not more than 2.5 g/cm3.

Abstract: A positive electrode with a positive electrode current collector and a positive electrode mixture layer, and the positive electrode mixture layer has first and second positive electrode mixture layers. The first positive electrode mixture layer comprises a positive electrode active material composed of compound A that contains Ni, Co, Al and Li. The second positive electrode mixture layer is disposed between the first positive electrode mixture layer and the positive electrode current collector, and comprises a positive electrode active material including: said compound A; and a Li-containing compound B which is smaller in specific capacity (mAh/g) and average particle diameter than said compound A. In said compound A, a ratio of Ni to the total number of moles of the metal elements except Li is 82 mol % or more. The average particle diameter of said compound B is 55% or less of the average particle diameter of said compound A.

Abstract: This secondary battery positive electrode includes: a positive electrode current collector; an intermediate layer provided on the positive electrode current collector; and a positive electrode mixture layer provided on the intermediate layer and including a positive electrode active material, wherein the intermediate layer includes a conductive material, a metal phosphate, and an inorganic compound which is not a metal phosphate and has a lower oxidizing power than the positive electrode active material.

Abstract: According to the present invention, a positive electrode is provided with: a positive electrode current collector which contains aluminum; a positive electrode mixture layer which contains a positive electrode active material that is configured of a lithium transition metal oxide; and an intermediate layer which is arranged between the positive electrode current collector and the positive electrode mixture layer. The intermediate layer contains inorganic compound particles, a conductive material and a binder; the circularity is from 5% to 75% (inclusive); the void fraction of the intermediate layer is from 30% to 69% (inclusive); and the average circularity of the inorganic compound particles is from 5% to 75% (inclusive).

Abstract: This positive electrode for secondary batteries is provided with: a positive electrode collector which has a plurality of recesses and projections in the surface; an intermediate layer which is provided on the surface of the positive electrode collector having the recesses and projections; and a positive electrode mixture layer which is provided on the intermediate layer and contains a positive electrode active material.

Abstract: This positive electrode is characterized by comprising a positive electrode collector, a positive electrode mixture layer that contains a lithium-containing transition metal oxide, and a protective layer that is arranged between the positive electrode collector and the positive electrode mixture layer, and is also characterized in that: the protective layer contains an inorganic compound that has a lower oxidative power than the lithium-containing transition metal oxide; a part of the lithium-containing transition metal oxide penetrates through the protective layer so as to be in contact with the positive electrode collector; and the coverage ? of the main surface of the positive electrode collector by the protective layer is 50% or more.

Abstract: The cylindrical secondary battery is provided with a wound electrode body, a positive electrode tab connected to a positive electrode, a cylindrical case body for housing the electrode body and the positive electrode tab, and a sealing body for sealing an opening of the case body. A negative electrode has, at a winding end of the negative electrode, a negative electrode current collector exposure section where no negative electrode active material layer is disposed, and the negative electrode current collector exposure section is disposed in contact with an inner surface of the case body. The positive electrode tab is disposed at the center in the longitudinal direction of the positive electrode and in a region where the number of layers of the positive electrode in a radial direction is smaller than in other regions in a cross-sectional area of the wound electrode body.

Abstract: According to the present invention, a positive electrode is provided with: a positive electrode current collector; a positive electrode active material layer which contains a positive electrode active material that is configured from a lithium transition metal oxide; a protective layer which is arranged between the positive electrode current collector and the positive electrode active material layer; and a positive electrode tab which is bonded with the positive electrode current collector at a positive electrode tab bonding part where the positive electrode active material layer and the protective layer are not formed so that the positive electrode current collector is exposed. An end edge of the positive electrode active material layer facing the positive electrode tab and an end edge of the protective layer facing the positive electrode tab are arranged in different positions in the longitudinal direction of the positive electrode.

Abstract: A positive electrode (11) according to one embodiment is provided with: a positive electrode collector (30); a first middle layer (32) disposed on one of two surfaces of the positive electrode collector (30), the surface being on the inner circumferential side when the positive electrode collector (30) is wound; a second middle layer (34) that is disposed on the other surface that is on the outer circumferential side; and a positive electrode mixed material layer (36) disposed on the first middle layer (32) and on the second middle layer (34). The first middle layer (32) and the second middle layer (34) contain insulating particles and an electrical conductor, and the thickness of the first middle layer (32) is less than the thickness of the second middle layer (34).

Abstract: This positive electrode includes: a positive electrode current collector; a positive electrode mixed material layer that is formed on at least one surface of the positive electrode current collector; and a protective layer which includes an insulating inorganic compound and a conductive material, and is interposed between the positive electrode current collector and the positive electrode mixed material layer. The protective layer includes secondary particles comprising agglomerated primary particles of the inorganic compound. The median value of the particle size of the secondary particles is 30 ?m or less.

Abstract: An electrode group includes a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a positive electrode lead electrically connected to the positive electrode. The positive electrode includes a positive electrode current collector and a positive electrode active material layer carried on each main surface of the positive electrode current collector. The positive electrode current collector has an exposed section that does not carry the positive electrode active material layer. The negative electrode includes a negative electrode current collector and a negative electrode active material layer carried on each main surface of the negative electrode current collector and has a first region and a second region. The mass of the negative electrode active material layer in the first region per unit area is smaller than the mass of the negative electrode active material layer in the second region per unit area.

Abstract: A secondary battery includes an electrode assembly including a positive electrode, a negative electrode, a first separator disposed on one side of the surface of the negative electrode and having a thickness T1, and a second separator disposed on the other side of the surface of the negative electrode and having a thickness T2. The thickness T2 of the second separator is larger than the thickness T1 of the first separator. The first separator includes a first porous film having a porosity P1, and the second separator includes a second porous film having a porosity P2. At least one of the first separator and the second separator includes a heat resistant layer. The positive electrode, the first separator, the negative electrode and the second separator are wound together such that the first separator is arranged on the outer side and the second separator is arranged on the inner side.