CARBON MATERIAL FOR NEGATIVE ELECTRODE OF LITHIUM SECONDARY BATTERY, PROCESS FOR PREPARING THE SAME, AND LITHIUM SECONDARY BATTERY PREPARED FROM SAID CARBON MATERIAL

摘要

A graphite material satisfying the following requirements: (A) a d002 value of not more than 0.336 nm; (B) a CI value of not less than 0.019 as determined 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 aaxis 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 crystalline carbon can be prepared by immersing a graphite material in an organic compound, washing the graphite material with an organic solvent, and then conducting carbonization.