CARBONACEOUS COATED GRAPHITE PARTICLES FOR NEGATIVE-ELECTRODE MATERIAL OF LITHIUM-ION SECONDARY CELL, NEGATIVE ELECTRODE FOR LITHIUM-ION SECONDARY CELL, AND LITHIUM-ION SECONDARY CELL

摘要

Provided is a negative-electrode material with which it is possible to obtain exceptional cell properties when said material is used as the negative-electrode material of a lithium-ion secondary cell. Carbonaceous coated graphite particles for the negative-electrode material of a lithium-ion secondary cell in which a carbonaceous material is provided on at least part of the surfaces of graphite particles that are obtained by anisotropically applying pressure to spheroidal and/or ellipsoidal graphite, wherein the carbonaceous coated graphite particles satisfy conditions (1) through (3) below. (1) The carbonaceous material content is 0.1-3.0 parts by mass per 100 parts by mass of the anisotropically pressurized graphite particles in the carbonaceous coated graphite particles. (2) The pore volume of pores measuring 1.1 µm or less in diameter is 0.100 mL/g or less as measured by a mercury porosimeter, and the ratio of the pore volume of pores measuring 0.54 µm or less in diameter with respect to said pore volume is 80% or greater. (3) The dibutyl phthalate (DBP) oil absorption is 40.0 mL/100 g or less.