IP Library › Granted Patent US 12,663,481
Granted Patent B2
US 12,663,481 · App. 18/391,181 · Granted Jun 23, 2026

Electrochemical state of health estimating method

Inventors: Lei Cheng (San Jose, CA); Jonathan Braaten (Sunnyvale, CA); Karim Gadelrab (Watertown, MA); Weiqi Ji (Sunnyvale, CA); Bjoern Stuehmeier (Santa Clara, CA); Christina Johnston (Spanish Fort, AL); Nathan Craig (Sunnyvale, CA); Jake Christensen (Elk Grove, CA)
Assignee: Robert Bosch GmbH
G01R31/392G01R31/367G01R31/3842
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Quick Facts
Patent No.
US 12,663,481
App. No.
18/391,181
Granted
Jun 23, 2026
Kind
B2
Abstract

An electrochemical state of health (SoH) estimating method. The method includes receiving in-operation voltage and/or current signals from a fuel cell stack during operation of the fuel cell stack at one or more operational condition(s). The method further includes comparing an in-operation voltage-current relationship based on the in-operation voltage or current signals at the operational condition(s) with a beginning of life (BOL) voltage-current relationship at the same or substantially the same operational condition(s) to obtain a voltage-current comparison at the operational condition(s). The method also includes estimating an SoH parameter in response to the voltage-current comparison.

Claims (34)

1 . An electrochemical state of health (SoH) estimating method for a polymer electrolyte fuel cell stack, the method comprising:

obtaining in-operation voltage and/or current signals from the polymer electrolyte fuel cell stack during operation of the polymer electrolyte fuel cell stack at one or more operational conditions;

determining an in-operation voltage-current relationship based on the in-operation voltage and/or current signals at the one or more operational conditions;

comparing the determined in-operation voltage-current relationship with a beginning of life (BOL) voltage-current relationship at the same or substantially the same one or more operational conditions to obtain a voltage-current comparison at the one or more operational conditions, the one or more operational conditions include relative humidity and/or pressure; and

estimating an SoH parameter for the polymer electrolyte fuel cell stack in response to the voltage-current comparison.

2 . The electrochemical SoH estimating method of claim 1 , wherein the comparing step is carried out using an aging model.

3 . The electrochemical SoH estimating method of claim 2 , wherein the aging model includes a linear regression model.

4 . The electrochemical SoH estimating method of claim 2 , wherein the aging model includes a nonlinear model, a stochastic model, and/or an uncertainty qualification model.

5 . The electrochemical SoH estimating method of claim 2 , wherein the aging model includes a Gaussian Process Regression, and the SoH parameter includes one or more nominal SoH parameters and one or more uncertainties associated with the one or more nominal SoH parameters.

6 . The electrochemical SoH estimating method of claim 1 further comprising adjusting the one or more operational conditions of the polymer electrolyte fuel cell stack in response to the SoH parameter.

7 . The electrochemical SoH estimating method of claim 2 , wherein the aging model includes a series of measurements of electrochemical performance decay and associated voltage-current relationships correlated to model SoH parameters.

8 . The electrochemical SoH estimating method of claim 7 , wherein the estimating step includes considering the series of measurements of electrochemical performance decay, the associated voltage-current relationships, and the model SoH parameters to estimate the SoH parameter.

9 . The electrochemical SoH estimating method of claim 1 , wherein the one or more operational conditions are measured with one or more polymer electrolyte fuel cell stack sensors.

10 . The electrochemical SoH estimating method of claim 1 , wherein the one or more operational conditions include relative humidity.

11 . The electrochemical SoH estimating method of claim 1 , wherein the SoH parameter is decay of the polymer electrolyte fuel cell stack.

12 . The electrochemical SoH estimating method of claim 1 , wherein the SoH parameter is lifetime loss of the polymer electrolyte fuel cell stack.

13 . The electrochemical SoH estimating method of claim 1 , wherein the SoH parameter is voltage loss of the polymer electrolyte fuel cell stack.

14 . The electrochemical SoH estimating method of claim 1 , wherein the operational conditions are only measured with one or more polymer electrolyte fuel cell stack sensors.

15 . The electrochemical SoH estimating method of claim 1 , wherein the one or more operational conditions include pressure.

16 . The electrochemical SoH estimating method of claim 1 , wherein the polymer electrolyte fuel cell stack is an individual polymer electrolyte fuel cell in the polymer electrolyte fuel cell stack.

17 . The electrochemical SoH estimating method of claim 1 , wherein the SoH parameter is oxygen transport resistance.

18 . The electrochemical SoH estimating method of claim 1 , wherein the SoH parameter is normalized catalyst mass activity.

19 . An electrochemical state of health (SoH) estimating method for a polymer electrolyte fuel cell stack, the method comprising:

obtaining in-operation voltage and/or current signals from the polymer electrolyte fuel cell stack during operation of polymer electrolyte fuel cell stack at one or more operational conditions;

determining an in-operation voltage-current relationship based on the in-operation voltage and/or current signals at the one or more operational conditions;

comparing the determined in-operation voltage-current relationship with a beginning of life (BOL) voltage-current relationship at the same or substantially the same one or more operational conditions to obtain a voltage-current comparison at the one or more operational conditions, the one or more operational conditions include relative humidity and/or pressure;

receiving an impendence calculation based on a response to an alternating current (AC) signal sent to the polymer electrolyte fuel cell stack; and

estimating an SoH parameter for the polymer electrolyte fuel cell stack in response to the voltage-current comparison and the impedance calculation.

20 . An electrochemical state of health (SoH) estimating method for a polymer electrolyte fuel cell stack, the method comprising:

obtaining in-operation voltage and/or current signals from the polymer electrolyte fuel cell stack during operation of the polymer electrolyte fuel cell stack at one or more operational conditions;

determining an in-operation voltage-current relationship based on the in-operation voltage and/or current signals at the one or more operational conditions;

comparing the determined in-operation voltage-current relationship with a beginning of life (BOL) voltage-current relationship at the same or substantially the same one or more operational conditions to obtain a voltage-current comparison at the one or more operational conditions, the one or more operational conditions include relative humidity and/or pressure;

estimating an SoH parameter for the polymer electrolyte fuel cell stack in response to the voltage-current comparison; and

transmitting the SoH parameter for the polymer electrolyte fuel cell stack to a diagnostics system of the polymer electrolyte fuel cell stack.