Performance of graphite electrode modified with carbon nanofibers for lithium ion secondary battery

Abstract

The spherical natural graphite A and the heat-treated graphite B obtained at 1800 T after pitch coating were used as anode base materials for a lithium ion secondary battery. Carbon nanofibers were incorporated into both graphite A and graphite B by mixing and ball milling. The effects that the carbon nanofiber content and ball milling have on the various electrochemical properties of the carbon nanofiber/graphite composite electrode (such as cyclic performance, charge/discharge capacity, and other electrochemical performances) were investigated. A portion of the graphite structure transformed from the hexagonal phase to the rhombohedral phase and the degree of graphitization increased after ball milling treatment, resulting in an increased charge/discharge capacity. The incorporation of a suitable amount of carbon nanofibers into the graphite electrode improved the cyclic performance as well as the initial charge/discharge capacity.