| 摘要 |
PURPOSE:To lessen self-discharge and improve storage property of a lithium secondary battery by using graphite powder for a negative pole material and containing practically no graphite powder with less than 10mum particle size. CONSTITUTION:In the case graphite powder is used for a negative pole material which can absorb and desorb lithium, practically no graphite powder with less than 10mum particle size is contained. For the physical properties of the graphite powder, d value (d002) in grating plane (002) of an X-ray diffraction is 3.35-3.40Angstrom , crystallite size in c-axial direction is 150Angstrom or more, specific surface area by BET method is 0.5-50m<2>/g, vacuum degree 1.9-2.3g/cm<3>. By using graphite powder containing no graphite powder whose particle size is small and has a lot of active points, sefl-discharge due to the reaction of the graphite and an electrolytic liquid is lessened and the storage property of the electrolytic liquid for a battery is improved. |
