| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a secondary battery which has a different structure than in conventional ones and can detect a charge state from the electric potential of the battery. <P>SOLUTION: The secondary battery includes a positive electrode containing an active material A and an active material B, which is characteristic in that; with the active material A alone, a potential fluctuation in a 80% or greater region of charge-discharge capacity within the working potential range of the secondary battery is within 0.2 V; that the active material A and the active material B are disposed at such a ratio that a voltage fluctuation in a charge-discharge region which is at least a 80% region of the charge-discharge capacity of the secondary battery is 0.2 V or less; and that, with the active material B alone, a charge potential is 0.2 V higher and a discharge potential is 0.2 V lower than an average potential in the charge-discharge region. A combination of the active material A whose region of potential change due to charging and discharging is small and the active material B whose region is large makes it possible to detect a charge state by a potential. This means that a stable charge-discharge potential is indicated in a broad charge state, and that a charge-discharge potential changes significantly before being overcharged or overdischarged. <P>COPYRIGHT: (C)2012,JPO&INPIT |
