| 摘要 |
<p>PROBLEM TO BE SOLVED: To highly accurately estimate a lithium concentration distribution in an active material, when the temperature of a lithium ion secondary battery decreases.SOLUTION: A battery system comprises: a temperature sensor (203) for detecting the temperature of a lithium ion secondary battery (1); and a controller (300) for calculating a lithium concentration distribution in spherical active material models (141b, 142b) included in the lithium ion secondary battery. In a state where the active material models are divided into a plurality of regions in a radial direction, the controller calculates a lithium concentration distribution showing the lithium concentration in each of the regions, using a diffusion equation. The controller makes the division number (Ninc) of the regions in the case where a detected temperature obtained by the temperature sensor is below a threshold level larger than the division number (Nref) of the regions in the case where the detected temperature is above the threshold level.</p> |
