| 摘要 |
PURPOSE:To make a secondary battery provided with high voltage, high discharge capacity, and also the safety by using as neg. electrode active substance a carbonaceous material having optimum structure in which Li is doped to a carbided mesophase mini-sphere material having undergone a high temp. baking process. CONSTITUTION:A carbided mesophase mini-sphere material is turned into neg. electrode black mix using a binder to constitute a neg. electrode for battery, wherein Li shall be doped to this mini-sphere material. The carbided mesophase mini-sphere material is prepared from a pitch whose (002) inter-plane spacing is no more than 3.45Angstrom and crystallite thickness in the c-axis direction is 300Angstrom or more. In this manner a carbonaceous material is used as a neg. electrode material, which has a large Li occluding ability, provides a low voltage at the time of Li segregation and low over-voltage at the time of Li insertion and segregation, and provides a high density as an electrode black mix, so that a resultant secondary battery will have characteristics with excellent high voltage and high discharge capacity and also an enhanced safety at the time of shortcircuiting. |
