CARBONACEOUS MATERIAL FOR NEGATIVE ELECTRODES OF NONAQUEOUS ELECTROLYTE SECONDARY BATTERIES, AND METHOD FOR PRODUCING SAME

摘要

The object of the present invention is to provide a carbonaceous material for an anode of a nonaqueous electrolyte secondary battery which uses a plant-derived organic material as a raw material, has high purity so that alkali metals such as the potassium element and alkali earth metals such as the calcium element are sufficiently removed by de-mineral treatment, and has excellent discharge capacity and efficiency, a novel manufacturing method capable of efficiently mass-producing the carbonaceous material, and a lithium ion secondary battery using the carbonaceous material. The problem described above can be solved by a carbonaceous material for an anode of a nonaqueous electrolyte secondary battery obtained by carbonizing a plant-derived organic material, the atom ratio (H/C) of hydrogen atoms and carbon atoms according to elemental analysis being at most 0.1, the average particle size Dv 50 being from 2 to 50 µm, the average interlayer spacing of the 002 planes determined by powder X-ray diffraction being from 0.365 nm to 0.400 nm, the potassium element content being at most 0.5 mass%, and the calcium element content being at most 0.02 mass%.