| 摘要 |
PROBLEM TO BE SOLVED: To provide a carbon material for a lithium ion secondary battery negative electrode with high charge/discharge capacity, high initial charge/ discharge efficiency, high charge/discharge speed, and high charge/discharge cycle characteristics, and its manufacturing method. SOLUTION: In this manufacturing method, a carbonaceous powder material filled in a container, having a filling density of 0.5-1.3 g /cm<3> is heat-treated at temperatures from room temperature to 1,500 deg.C in an atmosphere containing oxygen having an initial concentration of 1×10<-6> to 10×10<-6> mole/cm<3> , then graphitized at 2,400 deg.C or higher in an non-oxidizing, inert gas atmosphere, then cooled to 300 deg.C or lower. The carbon material obtained has such physical properties that the ratio of peak intensity (I1580 ) of a spectrum in a wave band of 1,580±100 cm<-1> to peak intensity (I1360 ) of a spectrum in a wave band of 1,360±100 cm<-1> is less than 0.2 in a laser Raman spectrum, and the intensity ratio of (101) diffraction peak to (100) diffraction peak in X ray diffraction is 1.0 or more. |
