| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an active material which is high in energy density, small in the deterioration in discharge capacity owing to the repetition of charge and discharge, and superior in cycle characteristics, and to provide a secondary battery arranged by use thereof.SOLUTION: An active material comprises a compound including Ti and P. The compound has, as a main crystal phase, a TiPOcrystal phase having a pseudo hexagonal structure. The TiPOcrystal phase having the pseudo hexagonal structure is small in volume change involved in acceptance and desorption of ions in charge of electrical conduction. Therefore, the active material like this is used for at least one of positive and negative electrodes of a secondary battery. The compound including Ti and P includes at least one crystal phase different from the TiPOcrystal phase having the pseudo hexagonal structure. A secondary battery comprises: a positive electrode; a negative electrode; and an electrolyte. In the secondary battery, at least one of the positive and negative electrodes includes the active material, and the electrolyte consists of an aqueous electrolytic solution.</p> |
