| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a state-of-charge estimation device capable of highly accurately estimating the state of charge of a lithium ion secondary battery without performing forced charging or discharging.SOLUTION: Provided is a state-of-charge estimation device 30 for estimating a state of charge of a lithium ion secondary battery 23. The state-of-charge estimation device 30 calculates surface lithium concentrations on the surfaces of active materials of the lithium ion secondary battery 23 on the basis of a voltage of the lithium ion secondary battery 23 or a current carried to the lithium ion secondary battery 23 during charging or discharging. The state-of-charge estimation device 30 calculates an average lithium concentration from the calculated surface lithium concentrations. The state-of-charge estimation device 30 estimates the state of charge of the lithium ion secondary battery 23 from the calculated average lithium concentration.</p> |
