| 摘要 |
PROBLEM TO BE SOLVED: To give high electron conductivity to the positive electrode material. SOLUTION: A positive electrode 12 and a negative electrode 14 are arranged opposite to each other through a separator 15, and the electrolyte 16 exists between them. The positive electrode 12 includes positive electrode material including Ca, Si and at least one of Al and B. In this positive electrode material, a part of a network of Si as a quadrivalent element formed by covalent binding is replaced with Al or B as a trivalent element, and Ca ion is housed in this network by a weak ion bond. The positive electrode material is charged in the network of Si, and has high electron conductivity even in the condition that Ca is removed. Consequently, internal resistance of a secondary battery is reduced, and a large discharging capacity is obtained. |
