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

摘要

To achieve reduction of irreversible capacity without deteriorating the other battery characteristics. A negative electrode material containing a carbonaceous substance, wherein the interplanar distance (d002) of the (002) plane of the carbonaceous substance as determined by a wide angle X-ray diffraction method is 0.338 nm or less and the cumulative pore volume of the pores having a diameter of from 2 nm to 3.5 nm (inclusive) in the carbonaceous substance as determined by a gas adsorption method is 3.0 × 10-2 cc/g or less, said carbonaceous substance, for example, containing a water-soluble polymer; a negative electrode for lithium ion secondary batteries; a lithium ion secondary battery; and a method for producing a negative electrode material.