NEGATIVE ELECTRODE MATERIAL FOR LITHIUM ION SECONDARY BATTERY AND MANUFACTURING METHOD THEREOF, NEGATIVE ELECTRODE FOR LITHIUM ION SECONDARY BATTERY, AND LITHIUM ION SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide: a negative electrode material for a lithium ion secondary battery negative electrode superior in cycle characteristics; and a method for manufacturing such a negative electrode material.SOLUTION: A method for manufacturing a negative electrode material for a lithium ion secondary battery comprises the steps of: preparing base particles made of a material including silicon atoms; and forming a carbon coating on the surface of each base particle into a coated particle. Supposing that the percentage of particles of 1 μm or smaller in particle diameter in a volume-based distribution of the base particles measured by a particle size distribution measuring device according to a laser diffraction method in a state in which the carbon coating is not formed is a%, and the percentage of particles of 1 μm or smaller in particle diameter in a volume-based distribution of the coated particles measured by the particle size distribution measuring device according to the laser diffraction method is b%, the formation of the carbon coating is performed so that "a" and "b" satisfy a/b≥3.SELECTED DRAWING: None