Added contact resistance

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Features
 
 - Steps in `Experiment` can now be tagged and cycle numbers be searched based on those tags ([#2593](https://github.com/pybamm-team/PyBaMM/pull/2593)).
+- New `contact resistance` option and corresponding parameter `Contact resistance [Ohm]` ([#2598](https://github.com/pybamm-team/PyBaMM/pull/2598)).
 
 # [v22.12](https://github.com/pybamm-team/PyBaMM/tree/v22.12) - 2022-12-31
 

pybamm/input/parameters/lead_acid/Sulzer2019.py

@@ -259,6 +259,7 @@ def get_parameter_values():
         "Positive current collector specific heat capacity [J.kg-1.K-1]": 256.0,
         "Negative current collector thermal conductivity [W.m-1.K-1]": 35.0,
         "Positive current collector thermal conductivity [W.m-1.K-1]": 35.0,
+        "Contact resistance [Ohm]": 0,
         # negative electrode
         "Negative electrode conductivity [S.m-1]": 4800000.0,
         "Negative electrode pore size [m]": 1e-07,

pybamm/input/parameters/lithium_ion/Ai2020.py

@@ -607,6 +607,7 @@ def get_parameter_values():
         "Nominal cell capacity [A.h]": 2.28,
         "Typical current [A]": 2.28,
         "Current function [A]": 2.28,
+        "Contact resistance [Ohm]": 0,
         # negative electrode
         "Negative electrode conductivity [S.m-1]": 100.0,
         "Maximum concentration in negative electrode [mol.m-3]": 28700.0,

pybamm/input/parameters/lithium_ion/Chen2020.py

@@ -295,6 +295,7 @@ def get_parameter_values():
         "Nominal cell capacity [A.h]": 5.0,
         "Typical current [A]": 5.0,
         "Current function [A]": 5.0,
+        "Contact resistance [Ohm]": 0,
         # negative electrode
         "Negative electrode conductivity [S.m-1]": 215.0,
         "Maximum concentration in negative electrode [mol.m-3]": 33133.0,

pybamm/input/parameters/lithium_ion/Chen2020_composite.py

@@ -395,6 +395,7 @@ def get_parameter_values():
         "Nominal cell capacity [A.h]": 5.0,
         "Typical current [A]": 5.0,
         "Current function [A]": 5.0,
+        "Contact resistance [Ohm]": 0,
         # negative electrode
         "Negative electrode conductivity [S.m-1]": 215.0,
         "Primary: Maximum concentration in negative electrode [mol.m-3]": 28700.0,

pybamm/input/parameters/lithium_ion/Ecker2015.py

@@ -498,6 +498,7 @@ def get_parameter_values():
         "Nominal cell capacity [A.h]": 0.15625,
         "Typical current [A]": 0.15652,
         "Current function [A]": 0.15652,
+        "Contact resistance [Ohm]": 0,
         # negative electrode
         "Negative electrode conductivity [S.m-1]": 14.0,
         "Maximum concentration in negative electrode [mol.m-3]": 31920.0,

pybamm/input/parameters/lithium_ion/Marquis2019.py

@@ -425,6 +425,7 @@ def get_parameter_values():
         "Nominal cell capacity [A.h]": 0.680616,
         "Typical current [A]": 0.680616,
         "Current function [A]": 0.680616,
+        "Contact resistance [Ohm]": 0,
         # negative electrode
         "Negative electrode conductivity [S.m-1]": 100.0,
         "Maximum concentration in negative electrode [mol.m-3]": 24983.2619938437,

pybamm/input/parameters/lithium_ion/Mohtat2020.py

@@ -419,6 +419,7 @@ def get_parameter_values():
         "Nominal cell capacity [A.h]": 5.0,
         "Typical current [A]": 5.0,
         "Current function [A]": 5.0,
+        "Contact resistance [Ohm]": 0,
         # negative electrode
         "Negative electrode conductivity [S.m-1]": 100.0,
         "Maximum concentration in negative electrode [mol.m-3]": 28746.0,

pybamm/input/parameters/lithium_ion/NCA_Kim2011.py

@@ -369,6 +369,7 @@ def get_parameter_values():
         "Nominal cell capacity [A.h]": 0.43,
         "Typical current [A]": 0.43,
         "Current function [A]": 0.43,
+        "Contact resistance [Ohm]": 0,
         # negative electrode
         "Negative electrode conductivity [S.m-1]": 100.0,
         "Maximum concentration in negative electrode [mol.m-3]": 28700.0,

pybamm/input/parameters/lithium_ion/OKane2022.py

@@ -583,6 +583,7 @@ def get_parameter_values():
         "Nominal cell capacity [A.h]": 5.0,
         "Typical current [A]": 5.0,
         "Current function [A]": 5.0,
+        "Contact resistance [Ohm]": 0,
         # negative electrode
         "Negative electrode conductivity [S.m-1]": 215.0,
         "Maximum concentration in negative electrode [mol.m-3]": 33133.0,

pybamm/input/parameters/lithium_ion/ORegan2022.py

@@ -963,6 +963,7 @@ def get_parameter_values():
         "Nominal cell capacity [A.h]": 5.0,
         "Typical current [A]": 5.0,
         "Current function [A]": 5.0,
+        "Contact resistance [Ohm]": 0,
         # negative electrode
         "Negative electrode conductivity [S.m-1]": 215.0,
         "Maximum concentration in negative electrode [mol.m-3]": 29583.0,

pybamm/input/parameters/lithium_ion/Prada2013.py

@@ -268,6 +268,7 @@ def get_parameter_values():
         "Nominal cell capacity [A.h]": 1.1,
         "Current function [A]": 1.1,
         "Typical current [A]": 1.1,
+        "Contact resistance [Ohm]": 0,
         # negative electrode
         "Negative electrode conductivity [S.m-1]": 215.0,
         "Maximum concentration in negative electrode [mol.m-3]": 33133.0,

pybamm/input/parameters/lithium_ion/Ramadass2004.py

@@ -438,6 +438,7 @@ def get_parameter_values():
         "Nominal cell capacity [A.h]": 1.0,
         "Typical current [A]": 1.0,
         "Current function [A]": 1.0,
+        "Contact resistance [Ohm]": 0,
         # negative electrode
         "Negative electrode conductivity [S.m-1]": 100.0,
         "Maximum concentration in negative electrode [mol.m-3]": 30555.0,

pybamm/input/parameters/lithium_ion/Xu2019.py

@@ -270,6 +270,7 @@ def get_parameter_values():
         "Nominal cell capacity [A.h]": 0.0024,
         "Typical current [A]": 0.0024,
         "Current function [A]": 0.0024,
+        "Contact resistance [Ohm]": 0,
         # negative electrode
         "Negative electrode OCP [V]": 0.0,
         "Negative electrode conductivity [S.m-1]": 10776000.0,

pybamm/input/parameters/lithium_ion/testing_only/cells/Enertech_Ai2020/parameters.csv

@@ -33,4 +33,5 @@ Positive current collector thermal conductivity [W.m-1.K-1],237,CRC Handbook,alu
 # Electrical,,,
 Nominal cell capacity [A.h], 2.28,Ai 2020,2.28/34
 Typical current [A], 2.28,Ai 2020,
-Current function [A], 2.28,default current function,
+Current function [A], 2.28,default current function,
+Contact resistance [Ohm], 0,,

pybamm/models/full_battery_models/base_battery_model.py

@@ -187,8 +187,9 @@ class BatteryModelOptions(pybamm.FuzzyDict):
     def __init__(self, extra_options):
         self.possible_options = {
             "calculate discharge energy": ["false", "true"],
-            "cell geometry": ["arbitrary", "pouch"],
             "calculate heat source for isothermal models": ["false", "true"],
+            "cell geometry": ["arbitrary", "pouch"],
+            "contact resistance": ["false", "true"],
             "convection": ["none", "uniform transverse", "full transverse"],
             "current collector": [
                 "uniform",
@@ -406,6 +407,17 @@ def __init__(self, extra_options):
                     "current density as a state' must be 'true'"
                 )
 
+        # Options not yet compatible with contact resistance
+        if options["contact resistance"] == "true":
+            if options["operating mode"] == "explicit power":
+                raise NotImplementedError(
+                    "Contact resistance not yet supported for explicit power."
+                )
+            if options["operating mode"] == "explicit resistance":
+                raise NotImplementedError(
+                    "Contact resistance not yet supported for explicit resistance."
+                )
+
         # Options not yet compatible with particle-size distributions
         if options["particle size"] == "distribution":
             if options["lithium plating"] != "none":

pybamm/models/submodels/electrode/base_electrode.py

@@ -111,7 +111,9 @@ def _get_standard_current_variables(self, i_s):
 
         return variables
 
-    def _get_standard_current_collector_potential_variables(self, phi_s_cn, phi_s_cp):
+    def _get_standard_current_collector_potential_variables(
+        self, phi_s_cn, phi_s_cp, delta_phi_contact
+    ):
         """
         A private function to obtain the standard variables which
         can be derived from the potentials in the current collector.
@@ -122,6 +124,8 @@ def _get_standard_current_collector_potential_variables(self, phi_s_cn, phi_s_cp
             The potential in the negative current collector.
         phi_s_cp : :class:`pybamm.Symbol`
             The potential in the positive current collector.
+        delta_phi_contact : :class:`pybamm.Symbol`
+            The potential difference due to the contact resistance, if any.
 
         Returns
         -------
@@ -141,8 +145,9 @@ def _get_standard_current_collector_potential_variables(self, phi_s_cn, phi_s_cp
         V = pybamm.boundary_value(phi_s_cp, "positive tab")
         V_dim = pybamm.boundary_value(phi_s_cp_dim, "positive tab")
 
-        # Voltage is local current collector potential difference at the tabs, in 1D
-        # this will be equal to the local current collector potential difference
+        # Voltage is local current collector potential difference at the tabs.
+        # In 1D this will be equal to the local current collector potential difference.
+        # The potential drop due to contact resistance (if any) is subtracted.
 
         variables = {
             "Negative current collector potential": phi_s_cn,
@@ -151,8 +156,8 @@ def _get_standard_current_collector_potential_variables(self, phi_s_cn, phi_s_cp
             "Positive current collector potential [V]": phi_s_cp_dim,
             "Local voltage": V_cc,
             "Local voltage [V]": self.param.ocv_ref + V_cc * pot_scale,
-            "Terminal voltage": V,
-            "Terminal voltage [V]": V_dim,
+            "Terminal voltage": V - delta_phi_contact,
+            "Terminal voltage [V]": V_dim - delta_phi_contact * pot_scale,
         }
 
         return variables
@@ -191,9 +196,15 @@ def _get_standard_whole_cell_variables(self, variables):
             phi_s_cn = variables["Negative current collector potential"]
             phi_s_p = variables["Positive electrode potential"]
             phi_s_cp = pybamm.boundary_value(phi_s_p, "right")
+            if self.options["contact resistance"] == "true":
+                param = self.param
+                I = variables["Current [A]"]
+                delta_phi_contact = I * param.R_contact / param.potential_scale
+            else:
+                delta_phi_contact = pybamm.Scalar(0)
             variables.update(
                 self._get_standard_current_collector_potential_variables(
-                    phi_s_cn, phi_s_cp
+                    phi_s_cn, phi_s_cp, delta_phi_contact
                 )
             )
 

pybamm/parameters/electrical_parameters.py

@@ -29,6 +29,7 @@ def _set_dimensional_parameters(self):
 
         self.I_typ = pybamm.Parameter("Typical current [A]")
         self.Q = pybamm.Parameter("Nominal cell capacity [A.h]")
+        self.R_contact = pybamm.Parameter("Contact resistance [Ohm]")
         self.C_rate = pybamm.AbsoluteValue(self.I_typ / self.Q)
         self.n_electrodes_parallel = pybamm.Parameter(
             "Number of electrodes connected in parallel to make a cell"

pybamm/parameters/lead_acid_parameters.py

@@ -67,6 +67,7 @@ def _set_dimensional_parameters(self):
         # Electrical
         self.I_typ = self.elec.I_typ
         self.Q = self.elec.Q
+        self.R_contact = self.elec.R_contact
         self.C_rate = self.elec.C_rate
         self.n_electrodes_parallel = self.elec.n_electrodes_parallel
         self.n_cells = self.elec.n_cells

pybamm/parameters/lithium_ion_parameters.py

@@ -87,6 +87,7 @@ def _set_dimensional_parameters(self):
         # Electrical
         self.I_typ = self.elec.I_typ
         self.Q = self.elec.Q
+        self.R_contact = self.elec.R_contact
         self.C_rate = self.elec.C_rate
         self.n_electrodes_parallel = self.elec.n_electrodes_parallel
         self.n_cells = self.elec.n_cells

tests/unit/test_models/test_full_battery_models/test_base_battery_model.py

@@ -15,8 +15,9 @@
 
 PRINT_OPTIONS_OUTPUT = """\
 'calculate discharge energy': 'false' (possible: ['false', 'true'])
-'cell geometry': 'pouch' (possible: ['arbitrary', 'pouch'])
 'calculate heat source for isothermal models': 'false' (possible: ['false', 'true'])
+'cell geometry': 'pouch' (possible: ['arbitrary', 'pouch'])
+'contact resistance': 'false' (possible: ['false', 'true'])
 'convection': 'none' (possible: ['none', 'uniform transverse', 'full transverse'])
 'current collector': 'uniform' (possible: ['uniform', 'potential pair', 'potential pair quite conductive'])
 'dimensionality': 0 (possible: [0, 1, 2])
@@ -310,7 +311,6 @@ def test_options(self):
         # plating model
         with self.assertRaisesRegex(pybamm.OptionError, "lithium plating"):
             pybamm.BaseBatteryModel({"lithium plating": "bad plating"})
-
         with self.assertRaisesRegex(
             pybamm.OptionError, "lithium plating porosity change"
         ):
@@ -320,6 +320,25 @@ def test_options(self):
                     "plating porosity change"
                 }
             )
+
+        # contact resistance
+        with self.assertRaisesRegex(pybamm.OptionError, "contact resistance"):
+            pybamm.BaseBatteryModel({"contact resistance": "bad contact resistance"})
+        with self.assertRaisesRegex(NotImplementedError, "Contact resistance not yet"):
+            pybamm.BaseBatteryModel(
+                {
+                    "contact resistance": "true",
+                    "operating mode": "explicit power",
+                }
+            )
+        with self.assertRaisesRegex(NotImplementedError, "Contact resistance not yet"):
+            pybamm.BaseBatteryModel(
+                {
+                    "contact resistance": "true",
+                    "operating mode": "explicit resistance",
+                }
+            )
+
         # stress-induced diffusion
         with self.assertRaisesRegex(pybamm.OptionError, "cannot have stress"):
             pybamm.BaseBatteryModel({"stress-induced diffusion": "true"})

tests/unit/test_models/test_full_battery_models/test_lithium_ion/base_lithium_ion_tests.py

@@ -67,6 +67,10 @@ def test_well_posed_thermal_2plus1D(self):
         }
         self.check_well_posedness(options)
 
+    def test_well_posed_contact_resistance(self):
+        options = {"contact resistance": "true"}
+        self.check_well_posedness(options)
+
     def test_well_posed_particle_uniform(self):
         options = {"particle": "uniform profile"}
         self.check_well_posedness(options)