Characteristics and hydrogen desorption property of nanostructured graphite produced by grinding in vacuum atmospheres [Translated]†

Abstract

The natural graphite ground in vacuum atmosphere by a vibration ball mill is found to have the porous nanostructure consisting of the agglomeration of primary particles of approximately 20nm in size. Such nanostructured graphite particles were used as a raw material to experientially investigate the hydrogen desorption characteristics of the products ground in high pressure hydrogen atmospheres by 3 types of milling machines including a ball mill, a vibration ball mill and planetary ball mill. We experimentally investigated the relationship between the nanostructures and the hydrogen desorption temperature of the products obtained by grinding the nanostructured graphite in hydrogen atmosphere. The micropores and mesopores in the nanostructured graphite prepared by a vibration ball milling in vacuum atmosphere were almost maintained during the further grinding by the ball milling in hydrogen atmosphere. The starting temperature of hydrogen desorption of the ground products of the nanostructured graphite, which was prepared by a vibration ball mill in vacuum atmosphere, decreased to 470K from 600K, which had been previously reported.† This paper, published originally in Japanese in J. Soc. Powder Technology, Japan, 42, 185-191 (2005), is published in KONA with the permission of the editorial committee of the Soc. Powder Technology, Japan.

Keywords

• natural graphite
• grinding
• nanostructure
• hydrogen desorption