Graphite material for negative electrode of lithium ion secondary cell and method for producing the same

A lithium ion secondary cell comprising a negative electrode and a positive electrode, the negative electrode comprising a graphite material being substantially configured of a graphite particle in which defects enabling intercalation/deintercalation of lithium ions have been formed on a basal plane,

• wherein the graphite particle comprises a calcium (Ca) component in the basal plane, and
• calcium carbonate is included as the calcium component.

A method for producing a graphite material for a negative electrode of a lithium ion secondary cell, the method comprising:

• supplying a calcium-containing substance to a surface of a graphite particle;
• and
• supporting a calcium component in a basal plane of the graphite particle by heat treating the graphite particle supplied with the calcium-containing substance on the surface thereof in a temperature range in which the calcium-containing substance and the basal plane can react with each other to generate defects enabling intercalation/deintercalation of lithium ions on the basal plane of the graphite particle.