| 摘要 |
PROBLEM TO BE SOLVED: To speedily and surely evaluate safety for overcharging of a substance for activating a positive electrode used for a lithium ion secondary battery, without having to assemble the battery. SOLUTION: For evaluating safety for overcharging of a substance for activating a positive electrode of a hexagonal system layer structure formed of transition metallic elements and lithium, a powder X-ray diffraction measurement is executed for the substance for activating the positive electrode which has not been charged, as a result, the substance for activating the positive electrode having a half-width of the diffraction peak of a lattice plane or β1/2(003) in a range of 0.095 degrees to 0.130 degrees is evaluated as a substance satisfactory for safety in overcharging. |
