パルスCVI法により表面修飾した炭素材料のリチウムイオン電池負極特性

Abstract

Pyrolytic carbon (pyrocarbon) was coated on the anode carbon such as graphitized Mesocarbon Microbeads (MCMB) and natural graphites (NG) form 30 % C3H8-H2 at 950 ˚C using pressure-pulsed chemical vapor infiltration technique. It was revealed from TEM, XRD and Raman spectroscopy that the crystallinity of pyrocarbon films was lower than that of the graphitized MCMB and NG as the core carbons. Large irreversible capacity was observed in the original core carbons in PC/EC/DEC (2:1:1 vol.%) electrolyte, however, irreversible capacity was reduced by coating with 3 mass% pyrocarbon, which would be attributed to the low crystallinity of pyrocarbon. Under the condition of high current density of 450 - 600 mA/g, capacities of the pyrocarbon-coated samples were higher than those of the original core carbons.