GRAPHITE NANOFIBERS, ELECTRON-EMITTING SOURCE AND METHOD FOR PREPARING THE SAME, DISPLAY ELEMENT EQUIPPED WITH THE ELECTRON-EMITTING SOURCE AS WELL AS LITHIUM ION SECONDARY BATTERY

摘要

A graphite nanofiber material herein provided has a cylindrical structure in which graphene sheets each having an ice-cream cone-like shape whose tip is cut off are put in layers through catalytic metal particles; or a structure in which small pieces of graphene sheets having a shape adapted for the facial shape of a catalytic metal particle are put on top of each other through the catalytic metal particles. The catalytic metal comprises Fe, Co or an alloy including at least one of these metals. The material can be used for producing an electron-emitting source, a display element, which is designed in such a manner that only a desired portion of a luminous body emits light, a negative electrode carbonaceous material for batteries and a lithium ion secondary battery.