Graphite material with lattice distortion for use in lithium-ion secondary battery negative electrodes, and lithium-ion secondary battery

摘要

This disclosure concerns graphite materials having lattice distortion for lithium-ion secondary battery negative electrode obtained by a manufacturing method comprising the steps of: pulverizing and classifying a raw coke composition obtained from a heavy-oil composition undergone coking by delayed coking process, the raw coke composition having a H/C atomic ratio that is a ratio of hydrogen atoms H and carbon atoms C of 0.30 to 0.50 and having a micro-strength of 7 to 17 mass % to obtain powder of the raw coke composition; giving compressive stress and shear stress to the powder of the raw coke composition so that average circularity is 0.91 to 0.97 to obtain round powder; heating the round powder to obtain a carbonized composition; and graphitizing the carbonized composition.