US 12,292,482 B2
Method for determining the ageing of an individual battery cell as well as a method for controlling a battery
Friedrich Emanuel Hust, Esslingen (DE); and Heiko Witzenhausen, Esslingen (DE)
Assigned to Mercedes-Benz Group AG, Stuttgart (DE)
Appl. No. 18/868,636
Filed by Mercedes-Benz Group AG, Stuttgart (DE)
PCT Filed Feb. 22, 2024, PCT No. PCT/EP2024/054539
§ 371(c)(1), (2) Date Nov. 22, 2024,
PCT Pub. No. WO2024/199836, PCT Pub. Date Oct. 3, 2024.
Claims priority of application No. 10 2023 001 210.6 (DE), filed on Mar. 29, 2023.
Prior Publication US 2025/0110184 A1, Apr. 3, 2025
Int. Cl. H02J 7/00 (2006.01); G01R 31/392 (2019.01); G01R 31/396 (2019.01)
CPC G01R 31/392 (2019.01) [G01R 31/396 (2019.01); H02J 7/007182 (2020.01)] 13 Claims
OG exemplary drawing
 
1. A method for determining ageing of an individual battery cell of a lithium-ion battery, comprising:
the individual battery cell is actively charged or discharged with a power pulse, or such a power pulse charging or discharging the individual battery cell is detected during operation of the lithium-ion battery, wherein an occurring current pulse and a voltage response of the individual battery cell are recorded in an idle phase following the power pulse with lower power or without power and a relaxation of the individual battery cell is evaluated, wherein at least a relaxation time constant (τ) is determined and stored, after which in each case a charging curve and a discharging curve is formed over the charge of the individual battery cell from the currently detected and already stored relaxation time constant (τ) when charging or discharging the individual battery cell by the power pulse, wherein a current capacity (K1) of the individual battery cell is deduced on a basis of a point where the charging curve and the discharging curve intersect.