| 摘要 |
PROBLEM TO BE SOLVED: To provide a positive electrode material capable of obtaining high charge and discharge efficiency and a secondary battery using it. SOLUTION: This positive electrode material contains Li and Ni composite oxide or Li, Ni and Co composite oxide. These composite oxides have the characteristics that they do not have the current peak of a reduction wave in the range between 3.4 V and 3.6 V on a current-potential curve obtained by cyclie-voltammetry when setting a Li metal potential as a reference. The Li and Ni composite oxide has a bigger mol ratio Ni/Li of Ni to Li than 1 of stoichiometric composite, and has non-stoichiometric property. Thereby, occurrence of a distortion in a charge and discharge process is suppressed in a positive electrode using this positive electrode material, polarization does not grow even at the end of discharge and high charge and discharge efficiency can be obtained. |
