Lithium-ion secondary battery, battery apparatus, and electric apparatus

Abstract

The present disclosure provides a lithium-ion secondary battery, a battery apparatus, and an electric apparatus. The lithium-ion secondary battery includes a positive electrode plate. The positive electrode plate includes a positive electrode current collector and a positive electrode film layer disposed on at least one side of the positive electrode current collector. The positive electrode film layer includes a positive electrode active material. The positive electrode active material includes lithium transition metal phosphate particles. The lithium transition metal phosphate particles include a lithium transition metal phosphate matrix and a coating layer located on at least part of a surface of the lithium transition metal phosphate matrix, and the coating layer includes a carbon element. In a cross section of the positive electrode film layer in a thickness direction of the electrode plate, based on a total number of the lithium transition metal phosphate particles, a number proportion of particles I having a particle size of less than 300 nm is 60% to 70%. An RA50 of roughness of the lithium transition metal phosphate particles is greater than or equal to 0.86.