Abstract: Provided is a positive electrode mixture for a secondary battery, the positive electrode mixture allowing provision of a secondary battery that exhibits a high capacity maintenance rate in a charge-discharge cycle. The positive electrode mixture for a secondary battery comprises a positive electrode active material, a binder, and an organic acid, wherein the positive electrode active material comprises a lithium nickel complex oxide having a layered crystal structure, the binder comprises a vinylidene fluoride-based polymer, and when a solution prepared by suspending the positive electrode active material in pure water has a pH of A, and the content of the organic acid per 100 parts by mass of the positive electrode active material is B parts by mass, A and B satisfy the following expression (1).

Abstract: There is provided a positive electrode for a lithium ion secondary battery, comprising a current collector and a positive electrode active material layer on the current collector, wherein the positive electrode active material layer comprises a positive electrode active material, a conductive auxiliary agent and a binder; a porosity of the positive electrode active material layer is 20% or lower; the positive electrode active material comprises a lithium composite oxide, and a BET specific surface area of the positive electrode active material is 0.1 to 1 m2/g; at least a part of the conductive auxiliary agent comprises spherical amorphous carbon particles; and a content of the conductive auxiliary agent is 1.8 to 6% by mass with respect to the positive electrode active material.

Abstract: Provided is a positive electrode mixture for a secondary battery, the positive electrode mixture allowing provision of a secondary battery that exhibits a high capacity maintenance rate in a charge-discharge cycle. The positive electrode mixture for a secondary battery comprises a positive electrode active material, a binder, and an organic acid, wherein the positive electrode active material comprises a lithium nickel complex oxide having a layered crystal structure, the binder comprises a vinylidene fluoride-based polymer, and when a solution prepared by suspending the positive electrode active material in pure water has a pH of A, and the content of the organic acid per 100 parts by mass of the positive electrode active material is B parts by mass, A and B satisfy the following expression (1).

Abstract: A positive electrode for a lithium-ion secondary battery of the present invention includes a collector for a positive electrode and a positive electrode active material layer provided on the collector for a positive electrode. The positive electrode active material layer includes a positive electrode active material, a conductive auxiliary agent, and a binder, the conductive auxiliary agent includes flake-shaped graphite having an average thickness of 0.5 ?m or less, and, when an average particle diameter of the positive electrode active material is represented by D50, the average particle diameter of the flake-shaped graphite is equal to or more than (3× active material D50/5) and equal to or less than (9× active material D50/10).

Abstract: A secondary battery includes an laminated electrode in which positive electrode (1) and a negative electrode are arranged with a separator interposed therebetween. Positive electrode collector foil (3) is made of aluminum or an aluminum alloy. Positive electrode mixture layer (2) includes a positive electrode active material containing nickel and lithium. Protective layer (4) formed between positive electrode collector foil (3) and positive electrode mixture layer (2) includes a plurality of carbon particles (5). Carbon particles (5) are thin flakes which have principal plane (5a) and thickness (5b) orthogonal to principal plane (5a) and in which length L1 in one direction of principal plane (5a), length L2 in a direction orthogonal to the one direction within principal plane (5a), and length L3 in the direction of thickness (5b) satisfy the relationships of 5?(L1/L2)?1, (L1/L3)?5, L2>L3, and L1?4 ?m.