| abstract |
The purpose of the present invention is to provide: a carbonaceous material for negative electrodes of nonaqueous electrolyte secondary batteries, which uses a plant-derived organic material as a starting material, and from which alkali metals such as potassium element and alkaline earth metals such as calcium element are sufficiently removed by decalcification, so that the carbonaceous material has high purity and excellent discharge capacity and efficiency; a novel production method which is capable of efficiently mass-producing the carbonaceous material; and a lithium ion secondary battery which uses the carbonaceous material.nThe above-mentioned purpose can be achieved by a carbonaceous material for negative electrodes of nonaqueous electrolyte secondary batteries, which is obtained by carbonizing a plant-derived organic material, and which has an atomic ratio of hydrogen atoms to carbon atoms (H/C) as determined by elemental analysis of 0.1 or less, an average particle diameter (D v50 ) of 2-50 μm, an average interplanar spacing of the (002) plane as determined by a powder X-ray diffraction method of 0.365-0.400 nm, a potassium element content of 0.5% by mass or less and a calcium element content of 0.02% by mass or less. |