[Task] To provide an electrode material for a lithium ion secondary battery satisfying both electron conductivity and lithium diffusivity, an electrode in which the electrode material for a lithium ion secondary battery is used, and a lithium ion secondary battery in which the electrode is used.
[Means for Resolution] An electrode material for a lithium ion secondary battery including a carbonaceous coated electrode active material having primary particles of an electrode active material, secondary particles that are aggregates of the primary particles, and a carbonaceous film that coats the primary particles of the electrode active material and the secondary particles that are the aggregates of the primary particles, in which a ratio A/B of an average primary particle diameter A (nm) that is estimated from a specific surface area of the carbonaceous coated electrode active material obtained by a BET method to a crystallite diameter B (nm) of the electrode active material is 1 or more and 2.5 or less.