Electrode material for lithium ion secondary batteries, method for producing electrode material for lithium ion secondary batteries, and lithium ion secondary battery

An electrode material for a lithium ion secondary battery comprising:

• particles of a first active material that can function as a positive electrode active material or a negative electrode active material of a lithium ion secondary battery;
• and
• particles of a composite formed of particles of conductive carbon and particles of a second active material attached to the particles of the conductive carbon that can function as an active material of the same electrode as the first active material, wherein:
• the particles of the first active material having a diameter which is larger than the particles of the composite and is in the range of 100 nm to 100 μm,
• the particles of the conductive carbon in the composite having a diameter in a range of 10 nm to 300 nm, and the particles of the second active material in the composite having a diameter in a range of 1 nm to 200 nm,
• at least a part of a structure in the particles of the conductive carbon in the composite being destroyed,
• the particles of the composite filled in a gap formed between the particles of the first active material by kneading the particles of the composite and the particles of the first active material to obtain a kneaded material and adding pressure to the kneaded material, and
• the mixture ratio of the particles of the composite and the particles of the first active material being within the range of the mass ratio of 5 to 30:95 to 70.