METHODS OF INVERSE DETERMINATION OF MATERIAL PROPERTIES OF AN ELECTROCHEMICAL SYSTEM

• US 20120089353A1
• Filed: 10/03/2011
• Published: 04/12/2012
• Est. Priority Date: 10/03/2011
• Status: Active Grant

• Current Assignee: Sakti3, Inc
• Original Assignee: Sakti3, Inc
• Inventors: Zhang, Xiangchun, Wang, Chia-Wei, CHEN, Yen-Hung, Sastry, Ann Marie
• Granted Patent: US 8,190,383 B2
• Time in Patent Office: Days
• US Class Current: 702/63
• CPC Class Codes: G06F 2111/10 Numerical modelling
• CPC Class Codes: G06F 30/20 Design optimisation, verification or simulation optimisation, verification or simulation of circuit designs G06F30/30
• CPC Class Codes: H01M 10/42 Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells H01M10/60 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method of determining at least one material property of at least one component of an electrochemical system (fully or partially completed) using a process to reduce a difference of a performance characteristic between a numerical simulation result of a physical model and an empirical result. The method includes providing an electrochemical cell using a thin film process and performing a plurality of tests on the electrochemical cell to identify one or more target performance characteristics of the electrochemical cell. The method includes performing a surrogate based analysis process and determining a plurality of outputs of the surrogate based analysis function and determines a value of the unknown material property.

Claims

1. A method of designing a thin film battery device and manufacturing the thin film battery device by determining at least one material property of at least one component of an electrochemical system using a process to reduce a difference of a performance characteristic between a numerical simulation result of a physical model and an empirical result, the method comprising:

providing an electrochemical cell using a thin film process;

performing a plurality of tests on the electrochemical cell to identify one or more target performance characteristics of the electrochemical cell, the plurality of tests including respective operational modes of the electrochemical cell;

deriving a plurality of performance characteristics from the plurality of tests to provide a performance database, the performance database comprising the operational modes and the respective performance characteristics;

performing a surrogate based analysis process;

determining a plurality of outputs of the surrogate based analysis function; and

determining a value of the unknown material property.

2. The method of claim 1 wherein the electrochemical cell comprises an anode, cathode, separator, electrolyte, current collectors, substrate, and an overlying barrier material.

3. The method of claim 1 wherein the electrochemical cell is a partially completed electrochemical cell, the partially completed cell comprising at least two layers of any component of anode, cathode, separator, electrolyte, current collectors, substrate, and an overlying barrier material.

4. The method of claim 1 wherein the electrochemical cell is a partially completed electrochemical cell, the partially completed cell comprising at most ten layers of any component of anode, cathode, separator, electrolyte, current collectors, substrate, and an overlying barrier material.

5. The method of claim 1 wherein the unknown material property of the electrochemical cell is at least one of:

a transport property including at least one of electrical conductivity, ionic conductivity, ionic diffusivity, or thermal conductivity;

a kinetic property including at least a chemical reaction rate;

an interfacial property including a contact resistance;

a mechanical property including at least one of a Young'"'"'s Modulus, a Poisson'"'"'s ratio, a bulk modulus, a yield strength, an ultimate stress, a fracture stress, a thermal expansion coefficient, an intercalation expansion coefficient;

a geometric property including at least one of a porosity, a thickness, a curvature; and

a spatial variation of a mass density.

6. The method of claim 1 wherein the performance characteristics comprise more than one of a time variation of charge or discharge voltage curve, state of charge (SOC) variation of charge or discharge voltage curve, concentration profile, concentration gradient profile, temperature variation, temperature gradient profile, stress-strain variation, film curvature variation, and stress-strain gradient profile.

7. The method according to claim 1 wherein the operational mode of an electrochemical system comprises at least one of a profiles of constant current charge or discharge, variant current charge or discharge, constant power charge or discharge, variant constant power charge or discharge, constant voltage charge or discharge, variant voltage charge or discharge, and combinations of any of them in a constant temperature or any given temperature profile.

8. The method of claim 1 wherein the determining of the output uses at least one or more of a linear equation algorithm, Levenberg-Marquardt Algorithm, Gauss-Newton Algorithm, Trust-Region Dogleg Method, Trust-Region-Reflective Methods, medium-scale algorithms, or large-scale algorithms.

9. The method of claim 1, wherein the surrogate based analysis process comprises a computer aided engineering process, the computer aided engineering process is selected from at least one of a finite element method (FEM), a finite difference method (FDM), a boundary element analysis, element-free Galerkin (EFG) or Smoothed Particle Hydrodynamics (SPH) method.

10. The method of claim 1 wherein the surrogate based analysis process comprises:

providing an upper bound and a lower bound for an unknown material property of a material of a component of the electrochemical cell;

determining a plurality of sampling points between the upper bound and the lower bound of the unknown material property using a design of experiment (DOE) process;

determining a plurality of performance characteristics for the respective sampling points using a computer aided engineering process and a plurality of fixed parameters, the fixed parameters include at least one of intrinsic material properties, interface conditions, or operational conditions;

generating a surrogate based analysis function for a difference between the numerical simulation result and the empirical result for the electrochemical cell.

11. The method of claim 10 wherein the surrogate based analysis functions of target performance characteristics against sampling points include exponential, Fourier, Gaussian, interpolant, Kriging, polynomial, power, sinusoidal, Weibull, weight averaged, or any combination of these.

12. The method of claim 10 wherein the computer aided engineering process is for analysis of the electrochemical system and is a multi-physics model, the multi-physics model includes one or more functions to simulate one or more relationships, the relationships include mechanical properties and responses obtained via equilibrium or dynamic load considerations, thermal properties and temperature distributions obtained via heat transfer methods, or cell transport properties potential and concentrations distribution of species obtained via kinetic relations and/or fluid flow modeling.

13. The method of claim 1 wherein the plurality of tests are selected from at least one or more of a cell charge discharge test process, a temperature measurement process, a electrochemical impedance spectroscopy (EIS) test process, a strain gauge test process, a wafer bender test process, or an in-situ SEM cell charge discharge test process.

14. The method of claim 13 wherein the strain gauge test process measures a strain characteristic.

15. The method of claim 13 wherein the wafer bender test process measure a top surface deflection and curvature of the electrochemical system.

16. The method of claim 13 wherein the in-situ SEM cell charge discharge test process images a cross-session the electrochemical system and identifies a thickness and a volume variation during a charge discharge test process.

17. A method of designing a thin film battery device and manufacturing the thin film battery device by determining at least one material property of at least one component of an electrochemical system using a process to reduce a difference of a performance characteristic between a numerical simulation result of a physical model and an empirical result, the method comprising:

providing an electrochemical cell using a thin film process, wherein the electrochemical cell comprises an anode, cathode, separator, electrolyte, current collectors, substrate, and an overlying barrier material;

performing a plurality of tests on the electrochemical cell to identify one or more target performance characteristics of the electrochemical cell, the plurality of tests including respective operational modes of the electrochemical cell, wherein the plurality of tests are selected from at least one or more of a cell charge discharge test process, a temperature measurement process, a electrochemical impedance spectroscopy (EIS) test process, a strain gauge test process, a wafer bender test process, or an in-situ SEM cell charge discharge test process;

deriving a plurality of performance characteristics from the plurality of tests to provide a performance database, the performance database comprising the operational modes and the respective performance characteristics;

performing a surrogate based analysis process;

determining a plurality of outputs of the surrogate based analysis function, wherein the determining of the output uses at least one or more of a linear equation algorithm, Levenberg-Marquardt Algorithm, Gauss-Newton Algorithm, Trust-Region Dogleg Method, Trust-Region-Reflective Methods, medium-scale algorithms, or large-scale algorithms; and

determining a value of the unknown material property.

18. The method of claim 17 wherein the unknown material property of the electrochemical cell is at least one of:

a transport property including at least one of electrical conductivity, ionic conductivity, ionic diffusivity, or thermal conductivity;

a kinetic property including at least a chemical reaction rate;

an interfacial property including a contact resistance;

a mechanical property including at least one of a Young'"'"'s Modulus, a Poisson'"'"'s ratio, a bulk modulus, a yield strength, an ultimate stress, a fracture stress, a thermal expansion coefficient, an intercalation expansion coefficient;

a geometric property including at least one of a porosity, a thickness, a curvature; and

a spatial variation of a mass density.

19. The method of claim 17 wherein the surrogate based analysis process comprises:

providing an upper bound and a lower bound for an unknown material property of a material of a component of the electrochemical cell;

determining a plurality of sampling points between the upper bound and the lower bound of the unknown material property using a design of experiment (DOE) process;

determining a plurality of performance characteristics for the respective sampling points using a computer aided engineering process and a plurality of fixed parameters, the fixed parameters include at least one of intrinsic material properties, interface conditions, or operational conditions;

generating a surrogate based analysis function for a difference between the numerical simulation result and the empirical result for the electrochemical cell.

20. The electrode of claim 19 wherein the surrogate based analysis functions of target performance characteristics against sampling points include exponential, Fourier, Gaussian, interpolant, Kriging, polynomial, power, sinusoidal, Weibull, weight averaged, or any combination of these.