| 摘要 |
PROBLEM TO BE SOLVED: To provide: a composite active material for a lithium secondary battery, with which a lithium secondary battery can be manufactured, the lithium secondary battery including an electrode material that is small in volume expansion due to repeated charging and discharging and combining large charge and discharge capacity, high-rate charge and discharge characteristics and good cycle characteristics; and a method for producing the active material.SOLUTION: A composite active material for a lithium secondary battery comprises flat particles having one of shapes of substantially rounded disks, flattened ellipses and broad beans. The flat particles are made of one or more structures in which battery active material particles that can be combined with lithium ions are sandwiched between graphite folds, and the battery active material particles that can be combined with lithium ions have an average particle size of 1 μm or less. In a cross-section perpendicular to the flat surface of the flat particles, the graphite folds, except those located close to both ends of the cross-section in the long axis direction, are tilted from the direction of the axis perpendicular to the flat surface, and the orientation of the structure in which the battery active material particles that can be combined with lithium ions are sandwiched between graphite folds is substantially parallel to the flat surface. |
