NEGATIVE ELECTRODE MATERIAL FOR LITHIUM ION SECONDARY BATTERIES, AND METHOD FOR PRODUCING SAME

摘要

The present invention discloses a negative electrode material for lithium ion secondary batteries, which is characterized by being composed of: amorphous coated particles that are composed of a plurality of consolidated particles having no specific shape, said consolidated particles being obtained by consolidating a plurality of primary spheroidized graphite particles, and 0.5-20% by mass of an amorphous carbon layer that covers the surfaces of the consolidated particles and binds the consolidated particles with each other; and 0.5-20% by mass of a highly crystalline carbon layer that is formed so as to cover the outer surfaces of the amorphous coated particles and has an interplanar distance ascribed to CVD processing of 0.335 nm or more but less than 0.3369 nm. The negative electrode material for lithium ion secondary batteries is also characterized by having a porosity of 5% by volume or less. The present invention also discloses a method for producing the negative electrode material for lithium ion secondary batteries.