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1D Lithium-Ion Battery Model for the Capacity Fade Tutorial
Introduction
This is a template model containing the physics, geometry and mesh of a lithium-ion battery (without any capacity fade reactions or mechanisms added). The Capacity Fade of a Lithium-Ion Battery application available in the Application Library makes use of this model setup.
The battery cell model is created using the Lithium-Ion Battery interface. A more detailed description on how to set up this type of model can be found in the model example 1D Isothermal Lithium-Ion Battery.
Model Definition
The model is set up for a graphite/NCA battery cell. The materials are available from the Battery Material Library and mainly default settings are selected. The model domains consist of:
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Negative porous electrode: Graphite (MCMB LixC6) active material.
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Separator.
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Positive porous electrode: NCA (LiNi0.8Co0.15Al0.05O2) active material.
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Electrolyte: 1.0 M LiPF6 in EC:EMC (3:7 by weight)
The Lithium-Ion Battery interface accounts for:
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Electronic conduction in the electrodes
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Ionic charge transport in the electrodes and electrolyte/separator
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Material transport in the electrolyte, allowing for the introduction of the effects of concentration on ionic conductivity and concentration overpotential
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Material transport within the spherical particles that form the electrodes
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Butler-Volmer electrode kinetics using experimentally measured discharge curves for the equilibrium potential.
Application Library path: Battery_Design_Module/Batteries,_Lithium-Ion/capacity_fade_seed
Modeling Instructions
From the File menu, choose New.
New
In the New window, click  Model Wizard.
Model Wizard
1
In the Model Wizard window, click  1D.
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In the Select Physics tree, select Electrochemistry>Batteries>Lithium-Ion Battery (liion).
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Click Add.
4
Click  Study.
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In the Select Study tree, select Preset Studies for Selected Physics Interfaces>Time Dependent with Initialization.
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Click  Done.
Root
Add the model parameters from a text file.
Global Definitions
Parameters 1
1
In the Model Builder window, under Global Definitions click Parameters 1.
2
In the Settings window for Parameters, locate the Parameters section.
3
Click  Load from File.
4
Browse to the model’s Application Libraries folder and double-click the file capacity_fade_parameters.txt.
Geometry 1
Interval 1 (i1)
1
In the Model Builder window, under Component 1 (comp1) right-click Geometry 1 and choose Interval.
2
In the Settings window for Interval, locate the Interval section.
3
From the Specify list, choose Interval lengths.
4
In the table, enter the following settings:
Lengths (m)
L_neg
L_sep
L_pos
5
Click  Build All Objects.
Materials
Load the materials from the material library.
Add Material
1
In the Home toolbar, click  Add Material to open the Add Material window.
2
Go to the Add Material window.
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In the tree, select Battery>Electrolytes>LiPF6 in 3:7 EC:EMC (Liquid electrolyte, Li-ion Battery).
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Click  Add to Component 1 (comp1).
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In the tree, select Battery>Electrodes>Graphite Electrode, LixC6 MCMB (Negative, Li-ion Battery).
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Click  Add to Component 1 (comp1).
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In the tree, select Battery>Electrodes>NCA Electrode, LiNi0.8Co0.15Al0.05O2 (Positive, Li-ion Battery).
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Click  Add to Component 1 (comp1).
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In the Home toolbar, click  Add Material to close the Add Material window.
Definitions
Explicit selections are made in the model geometry.
Negative Electrode
1
In the Definitions toolbar, click  Explicit.
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In the Settings window for Explicit, type Negative Electrode in the Label text field.
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Select Domain 1 only.
Separator
1
In the Definitions toolbar, click  Explicit.
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In the Settings window for Explicit, type Separator in the Label text field.
3
Select Domain 2 only.
Positive Electrode
1
In the Definitions toolbar, click  Explicit.
2
In the Settings window for Explicit, type Positive Electrode in the Label text field.
3
Select Domain 3 only.
Lithium-Ion Battery (liion)
Porous Electrode 1
1
In the Model Builder window, under Component 1 (comp1) right-click Lithium-Ion Battery (liion) and choose Porous Electrode.
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In the Settings window for Porous Electrode, locate the Domain Selection section.
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From the Selection list, choose Negative Electrode.
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Locate the Electrode Properties section. From the Electrode material list, choose Graphite Electrode, LixC6 MCMB (Negative, Li-ion Battery) (mat2).
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Locate the Porous Matrix Properties section. In the εs text field, type epss_neg.
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In the εl text field, type epsl_neg.
Particle Intercalation 1
1
In the Model Builder window, expand the Porous Electrode 1 node, then click Particle Intercalation 1.
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In the Settings window for Particle Intercalation, locate the Material section.
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From the Particle material list, choose Graphite Electrode, LixC6 MCMB (Negative, Li-ion Battery) (mat2).
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Locate the Particle Transport Properties section. In the rp text field, type rp_neg.
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Click to expand the Particle Discretization section. In the Nel text field, type 5.
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Select the Fast assembly in particle dimension check box.
Porous Electrode Reaction 1
1
In the Model Builder window, click Porous Electrode Reaction 1.
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In the Settings window for Porous Electrode Reaction, locate the Material section.
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From the Material list, choose Graphite Electrode, LixC6 MCMB (Negative, Li-ion Battery) (mat2).
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Locate the Electrode Kinetics section. In the i0,ref(T) text field, type i0ref_neg.
Separator 1
1
In the Physics toolbar, click  Domains and choose Separator.
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In the Settings window for Separator, locate the Domain Selection section.
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From the Selection list, choose Separator.
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Locate the Porous Matrix Properties section. In the εl text field, type epsl_sep.
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Locate the Effective Transport Parameter Correction section. From the Electrolyte conductivity list, choose User defined. In the fl text field, type epsl_sep^brugl_sep.
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From the Diffusion list, choose User defined. In the fDl text field, type epsl_sep^brugl_sep.
Porous Electrode 2
1
In the Physics toolbar, click  Domains and choose Porous Electrode.
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In the Settings window for Porous Electrode, locate the Domain Selection section.
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From the Selection list, choose Positive Electrode.
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Locate the Electrode Properties section. From the Electrode material list, choose NCA Electrode, LiNi0.8Co0.15Al0.05O2 (Positive, Li-ion Battery) (mat3).
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Locate the Porous Matrix Properties section. In the εs text field, type epss_pos.
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In the εl text field, type epsl_pos.
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Locate the Effective Transport Parameter Correction section. From the Electrolyte conductivity list, choose User defined. In the fl text field, type liion.epsl^brugl_pos.
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From the Diffusion list, choose User defined. In the fDl text field, type liion.epsl^brugl_pos.
Particle Intercalation 1
1
In the Model Builder window, expand the Porous Electrode 2 node, then click Particle Intercalation 1.
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In the Settings window for Particle Intercalation, locate the Material section.
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From the Particle material list, choose NCA Electrode, LiNi0.8Co0.15Al0.05O2 (Positive, Li-ion Battery) (mat3).
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Locate the Particle Transport Properties section. In the rp text field, type rp_pos.
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Locate the Particle Discretization section. In the Nel text field, type 3.
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Select the Fast assembly in particle dimension check box.
Porous Electrode Reaction 1
1
In the Model Builder window, click Porous Electrode Reaction 1.
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In the Settings window for Porous Electrode Reaction, locate the Material section.
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From the Material list, choose NCA Electrode, LiNi0.8Co0.15Al0.05O2 (Positive, Li-ion Battery) (mat3).
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Locate the Electrode Kinetics section. In the i0,ref(T) text field, type i0ref_pos.
Initial Cell Charge Distribution 1
1
In the Physics toolbar, click  Global and choose Initial Cell Charge Distribution.
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In the Settings window for Initial Cell Charge Distribution, locate the Battery Cell Parameters section.
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In the Ecell,0 text field, type E_min.
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In the Qcell,0 text field, type Q0*1[m^2].
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Locate the Battery Cell Electrode Balancing section. In the fcycl,loss text field, type 0.
Negative Electrode Selection 1
1
In the Model Builder window, expand the Initial Cell Charge Distribution 1 node, then click Negative Electrode Selection 1.
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In the Settings window for Negative Electrode Selection, locate the Domain Selection section.
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From the Selection list, choose Negative Electrode.
Positive Electrode Selection 1
1
In the Model Builder window, click Positive Electrode Selection 1.
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In the Settings window for Positive Electrode Selection, locate the Domain Selection section.
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From the Selection list, choose Positive Electrode.
Electric Ground 1
1
In the Physics toolbar, click  Boundaries and choose Electric Ground.
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Select Boundary 1 only.
Global Definitions
Default Model Inputs
Set up the temperature value used in the entire model.
1
In the Model Builder window, under Global Definitions click Default Model Inputs.
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In the Settings window for Default Model Inputs, locate the Browse Model Inputs section.
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In the tree, select General>Temperature (K) - minput.T.
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Find the Expression for remaining selection subsection. In the Temperature text field, type T.
Definitions (comp1)
Piecewise 1 (pw1)
1
In the Home toolbar, click  Functions and choose Global>Piecewise.
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In the Settings window for Piecewise, type K in the Function name text field.
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Locate the Definition section. From the Smoothing list, choose Continuous function.
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Find the Intervals subsection. Click  Load from File.
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Browse to the model’s Application Libraries folder and double-click the file capacity_fade_piece_wise.txt.
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Click  Plot.
Variables 1
1
In the Model Builder window, right-click Definitions and choose Variables.
2
In the Settings window for Variables, locate the Variables section.
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Click  Load from File.
4
Browse to the model’s Application Libraries folder and double-click the file capacity_fade_variables.txt.
Study 1
Step 2: Time Dependent
1
In the Model Builder window, under Study 1 click Step 2: Time Dependent.
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In the Settings window for Time Dependent, locate the Study Settings section.
3
In the Output times text field, type range(0,180,(no_cycles+1)*t_cycling/t_factor).