| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a positive electrode active material for nonaqueous secondary batteries high in capacity and rate characteristic.SOLUTION: A positive electrode active material for nonaqueous secondary batteries comprises: a transition metal compound expressed by the chemical formula, AMDO(where "A" represents an alkali metal or alkali-earth metal, "M" represents a metal element including at least one transition metal element, "D" represents a typical element which makes a covalent bond with oxygen O to form an anion, and x, y and z satisfy: 0<x≤2; 1≤y≤2; and 3≤z≤7) with carbon coating formed thereon. In the positive electrode active material, the average primary particle diameter is in a range of 10-200 nm. The ratio of an actual measurement of the specific surface area measured with the carbon coating removed therefrom to a specific surface area calculated based on the assumption that particles having the average primary particle diameter are perfect spheres in shape is in a range of 1.0-2.0. The porosity of secondary particles is in a range of 33-48 vol.%. Preferably, the transition metal compound is expressed by the chemical formula LiMPO4 (where M represents a metal element including at least one of Fe, Mn, Co and Ni).</p> |
