LITHIUM-ION BATTERY ELECTRODEPOSITION DETECTION METHOD

A lithium-ion battery electrodeposition detection method includes: a positive-electrode SOC map generation step of irradiating a lithium-ion battery with an X-ray, performing an X-ray diffraction measurement of a positive-electrode active material layer, and generating a positive-electrode SOC map that indicates a distribution of a charging depth along a thickness direction of the positive-electrode active material layer; a SOC difference value detection step of detecting a SOC difference value which is a difference between a maximum value and a minimum value of the positive-electrode SOC map; and a determination step of comparing the SOC difference value with a preset threshold value and determining a presence or absence of a lithium electrodeposition of a negative-electrode active material layer.