Carbonaceous particles and carbonaceous fibers both coated with boron nitride, and lithium secondary cells produced by using the same as negative active material

摘要

Carbonaceous particles and carbonaceous fibers whose surfaces are covered with a boron nitride thin film, wherein the atomic concentration of boron C(B), the atomic concentration of carbon C(C) and the atomic concentration of nitrogen C(N) satisfy the following inequalities:in the surface region as measured by photoelectron spectroscopy. Also, lithium secondary batteries which employ these carbonaceous particles and carbonaceous fibers as negative electrode active materials.