US 12,334,769 B2
Method for establishing lithium secondary battery charging protocol, battery management system, battery pack, and battery cell charging device
Yeo Kyung Yoon, Daejeon (KR); Jeong In Yu, Daejeon (KR); and Yong Jun Kim, Daejeon (KR)
Assigned to LG ENERGY SOLUTION, LTD., Seoul (KR)
Appl. No. 18/840,058
Filed by LG Energy Solution, Ltd., Seoul (KR)
PCT Filed Nov. 8, 2023, PCT No. PCT/KR2023/017912
§ 371(c)(1), (2) Date Aug. 20, 2024,
PCT Pub. No. WO2024/101897, PCT Pub. Date May 16, 2024.
Claims priority of application No. 10-2022-0147927 (KR), filed on Nov. 8, 2022.
Prior Publication US 2025/0112485 A1, Apr. 3, 2025
Int. Cl. H02J 7/00 (2006.01); G01R 31/388 (2019.01); G01R 31/389 (2019.01)
CPC H02J 7/00712 (2020.01) [G01R 31/388 (2019.01); G01R 31/389 (2019.01)] 16 Claims
OG exemplary drawing
 
12. A battery management system comprising:
a voltage measurement portion for measuring: (1) a first open-circuit voltage (Vref) according to a state-of-charge (SOCx) for a two-electrode battery cell with a positive electrode and a negative electrode, when charged with a reference current and (2) a plurality of second open circuit voltages (Vc) according to the state-of-charge (SOCx) when charging the two-electrode battery cell with a plurality of different charging currents;
a memory portion for calculating an internal resistance value (RSOCx) according to the state-of-charge (SOCx) using an equation (RSOCx)=(Vc−Vref)/Ic for each of the different charging currents, wherein Ic is a current value for each of the different charging currents, and for computing a charging current-specific internal resistance profile mapping the internal resistance value according to the state-of-charge (SOCx) for each of the different charging currents; and
a control portion for identifying for each of the computed charging current-specific internal resistance profiles, each inflection point at which the internal resistance value (RSOCx) changes from an increasing trend to a decreasing trend, for determining a lowest resistance value among the inflection points for each of the different charging currents as a reference resistance value, and for determining, for each of the computed charging current-specific internal resistance profiles, the state-of-charge (SOCx) having the reference resistance value as a limit state-of-charge.