Abstract: A negative electrode for nonaqueous electrolyte secondary batteries therein a negative electrode mixture layer comprises a lower layer that is formed on the negative electrode core body side and an upper layer that is formed on the front surface side of the negative electrode mixture layer. Graphite particles contain: first graphite particles which have a circularity of less than 0.92; and second graphite particles which have a higher circularity than the first graphite particles. The ratio of the breaking strength of the first graphite particles to the breaking strength of the second graphite particles is 2 to 5. The content ratio of the first graphite particles relative to the graphite particles in the upper layer is 30% by mass or more, and is higher than the content ratio of the first graphite particles relative to the graphite particles in the lower layer.

Abstract: A non-aqueous electrolyte secondary battery provided with a positive electrode, a negative electrode, and a non-aqueous electrolyte. The negative electrode includes a negative electrode current collector and a negative electrode mixture layer formed on the surface of the negative electrode current collector. The negative electrode mixture layer includes a first negative electrode mixture layer opposite to the negative electrode current collector, and a second negative electrode mixture layer laminated on the surface of the first negative electrode mixture layer. The negative electrode mixture layer includes graphite particles and a highly dielectric material having a higher dielectric constant than the graphite particles. The porosity between the graphite particles in the second negative electrode mixture layer is greater than in the first negative electrode mixture layer.

Abstract: A negative electrode for nonaqueous electrolyte secondary batteries is provided with: a negative electrode current collector; a first negative electrode mix layer arranged on a surface of the negative electrode current collector; and a second negative electrode mix layer arranged on a surface of the first negative electrode mix layer. The first negative electrode mix layer contains a first carbon material having a true density of 2.1 g/cm3 to 2.3 g/cm3, the second negative electrode mix layer contains a second carbon material having a true density of 1.5 g/cm3 to 2.0 g/cm3, the inter-particle porosity of the second carbon material in the second negative electrode mix layer is larger than that of the first carbon material in the first negative electrode mix layer, and the ratio of the mass of the first negative electrode mix layer to that of the second negative electrode mix layer is 95:5 to 80:20.

Abstract: A negative electrode comprises a negative electrode collector, a first negative electrode mixture layer that is provided on the surface of the negative electrode collector, and a second negative electrode mixture layer that faces the positive electrode; the first negative electrode mixture layer and the second negative electrode mixture layer contain graphite particles; the ratio of the void fraction (S2) among the graphite particles in the second negative electrode mixture layer to the void fraction (S1) among the graphite particles in the first negative electrode mixture layer, namely S2/S1 is from 1.1 to 2.0; the ratio of the packing density (D2) of the second negative electrode mixture layer to the packing density (D1) of the first negative electrode mixture layer, namely D2/D1 is from 0.9 to 1.1; and the separator has a thickness of 10 ?m or less, while having a porosity of from 25% to 45%.

Abstract: A non-aqueous electrolyte secondary battery according to an aspect of the present disclosure is provided with a negative electrode having: a negative electrode collector: a first negative electrode mixture layer provided on the surface of the negative electrode collector; and a second negative electrode mixture layer provided on the surface of the first negative electrode mixture layer. Each of the first negative electrode mixture layer and the second negative electrode mixture layer contains graphite particles. The ratio (S2/S1) of the inter-particle porosity (S2) of the graphite particles in the second negative electrode mixture layer to the inter-particle porosity (S1) of the graphite particles in the first negative electrode mixture layer is 1.1-2.0. The ratio (D2/D1) of the filling density (D2) of the second negative electrode mixture layer to the filling density (D1) of the first negative electrode mixture layer is 0.9-1.1.

Abstract: Provided is the positive electrode active material for a potassium ion battery according to the embodiment comprises a compound represented by Formula (1), in which M represents at least one element selected from the group consisting of V, Fe, Co, Ni, and Mn, and x represents a number from 0 to 1; and is a positive electrode for a potassium ion battery comprising the positive electrode active material for a potassium ion battery according to the embodiment, or a potassium ion battery comprising the positive electrode for a potassium ion battery. KMOxPO4F1-x??[Formula (1)].

Abstract: Provided is the positive electrode active material for a potassium ion battery according to the embodiment comprises a compound represented by Formula (1), in which M represents at least one element selected from the group consisting of V, Fe, Co, Ni, and Mn, and x represents a number from 0 to 1; and is a positive electrode for a potassium ion battery comprising the positive electrode active material for a potassium ion battery according to the embodiment, or a potassium ion battery comprising the positive electrode for a potassium ion battery.