Pulse resistance based online temperature estimation for lithium-ion cells

JOURNAL OF POWER SOURCES

卷:490

Article

Ludwig, S.¹  Zilberman, I.¹  Horsche, M. F.¹  Wohlers, T.¹  Jossen, A.¹ 

[1] Tech Univ Munich TUM, Inst Elect Energy Storage Technol EES, Arcisstr 21, D-80333 Munich, Germany

关键词: Temperature estimation;    Cell resistance;    Battery management system;    State estimation;    Lithium-ion battery;   

DOI  :  10.1016/j.jpowsour.2021.229523

来源: Elsevier

【 摘 要 】

Knowing the temperature distribution within a battery pack is vital, because of the impact on capacity loss, power degradation and safety. Temperature measurements are usually realized with temperature sensors attached to a limited number of cells throughout the battery pack, leaving the majority of cells in larger battery systems unattended. This work presents a novel sensorless method for determining the temperature of a cell by exploiting the relation of the cell's overpotential and temperature exemplary using a 18650 nickel-rich/silicon-graphite cell, although the method is basically applicable to any cell. Current changes in the battery load are utilized as pulse excitation for the calculation of a direct-current resistance R-DC,R-Delta t determined after a certain time Delta t. Reference pulses at 10/20/30/40 degrees C are recorded to investigate the influence of state-of-charge and pulse rise/fall-time, as well as the pulse-current amplitude and direction on R-DC,R-Delta t. The analysis of the reference pulses shows that a Delta t in the 10 ms to 100 ms regime has the greatest sensitivity to temperature and the least dependence on other parameters. The method is finally validated using a 6s1p-module with an externally constant temperature gradient applied to the serial connection, showing an average estimation error smaller than 1K for each cell.

【 授权许可】

Free