摘要 |
A graphite material satisfying the following requirements: (A) a d002 value of not more than 0.336nm; (B) a CI value of not less than 0.019 as determind by equation (I) wherein D represents the density, c0 and Lc respectively represent the lattice constant and the grain size in the c-axis direction, a0 and La respectively represent the lattice constant and the grain size in the a-axis direction, and the superscript @ i" represents that the value is one for an ideal graphite; and (C) a discharge capacity exceeding 372 Ah/kg. The use of the above graphite material or a carbon material coated with a lowly crystalline carbon as the carbon material for a negative electrode can provide a secondary lithium battery having high discharge capacity and initial efficiency. The carbon material coated with a lowly cristalline carbon can be prepared by a immersing a graphite material in an organic compound, washing the graphite material with an organic solvent, and then conducting carbonization. <MATH> |