Carbonaceous electrode material for secondary battery and process for production thereof

摘要

A non-aqueous solvent-type secondary battery having a large charge-discharge capacity and exhibiting a high utilization rate of an active substance, such as lithium, and an excellent charge-discharge cycle characteristic, can be constituted by using a carbonaceous electrode material having a specific microtexture. The carbonaceous electrode material is characterized by having an average (002)-plane spacing d002 of 0.336-0.375 nm and a crystallite size in c-axis direction Lc(002) of at most 50 nm, respectively, as measured by X-ray diffraction method, and an optically anisotropic texture showing a fine mosaic texture when observed through a polarizing microscope. The carbonaceous material may suitably be produced through a process including the steps of: crosslinking a tar or pitch of a petroleum or coal origin, and carbonizing the crosslinked tar or pitch at a temperature of at least 800 DEG C. under a reduced pressure or in an inert gas atmosphere.