allow custom initial state

docs/source/api/parameters/parameter_sets.rst

@@ -44,7 +44,6 @@ For an example, see the `Marquis2019`_ parameter sets.
     def get_parameter_values():
         """Doc string for cell-alpha"""
         return {
-            "chemistry": "lithium_ion",
             "citation": "@book{van1995python, title={Python reference manual}}",
             # ...
         }

examples/scripts/print_model_parameter_combinations.py

@@ -5,9 +5,7 @@
 import pybamm
 
 all_options = pybamm.BatteryModelOptions({}).possible_options
-all_parameter_sets = [
-    k for k, v in pybamm.parameter_sets.items() if v["chemistry"] == "lithium_ion"
-]
+all_parameter_sets = [k for k, v in pybamm.parameter_sets.items()]
 
 for option_name, option_list in all_options.items():
     for parameter_set in all_parameter_sets:

src/pybamm/input/parameters/ecm/example_set.py

@@ -78,7 +78,6 @@ def get_parameter_values():
     cell_capacity = 100
 
     values = {
-        "chemistry": "ecm",
         "Initial SoC": 0.5,
         "Initial temperature [K]": 25 + 273.15,
         "Cell capacity [A.h]": cell_capacity,

src/pybamm/input/parameters/lead_acid/Sulzer2019.py

@@ -214,7 +214,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "lead_acid",
         # cell
         "Negative current collector thickness [m]": 0.0,
         "Negative electrode thickness [m]": 0.0009,

src/pybamm/input/parameters/lithium_ion/Ai2020.py

@@ -533,7 +533,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "lithium_ion",
         # sei
         "Ratio of lithium moles to SEI moles": 2.0,
         "SEI partial molar volume [m3.mol-1]": 9.585e-05,

src/pybamm/input/parameters/lithium_ion/Chen2020.py

@@ -225,7 +225,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "lithium_ion",
         # sei
         "Ratio of lithium moles to SEI moles": 2.0,
         "SEI partial molar volume [m3.mol-1]": 9.585e-05,

src/pybamm/input/parameters/lithium_ion/Chen2020_composite.py

@@ -333,7 +333,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "lithium_ion",
         # sei
         "Primary: Ratio of lithium moles to SEI moles": 2.0,
         "Primary: SEI partial molar volume [m3.mol-1]": 9.585e-05,

src/pybamm/input/parameters/lithium_ion/Ecker2015.py

@@ -498,7 +498,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "lithium_ion",
         # lithium plating
         "Lithium metal partial molar volume [m3.mol-1]": 1.3e-05,
         "Lithium plating kinetic rate constant [m.s-1]": 1e-10,

src/pybamm/input/parameters/lithium_ion/Ecker2015_graphite_halfcell.py

@@ -420,7 +420,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "lithium_ion",
         # lithium plating
         "Lithium plating kinetic rate constant [m.s-1]": 1e-10,
         "Exchange-current density for plating [A.m-2]"

src/pybamm/input/parameters/lithium_ion/MSMR_example_set.py

@@ -92,7 +92,6 @@ def get_parameter_values():
     experimental cycling data.
     """
     return {
-        "chemistry": "lithium_ion",
         # cell
         "Negative electrode thickness [m]": 8.52e-05,
         "Separator thickness [m]": 1.2e-05,

src/pybamm/input/parameters/lithium_ion/Marquis2019.py

@@ -350,7 +350,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "lithium_ion",
         # sei
         "Ratio of lithium moles to SEI moles": 2.0,
         "SEI partial molar volume [m3.mol-1]": 9.585e-05,

src/pybamm/input/parameters/lithium_ion/Mohtat2020.py

@@ -336,7 +336,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "lithium_ion",
         # lithium plating
         "Lithium metal partial molar volume [m3.mol-1]": 1.3e-05,
         "Exchange-current density for plating [A.m-2]": 0.001,

src/pybamm/input/parameters/lithium_ion/NCA_Kim2011.py

@@ -309,7 +309,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "lithium_ion",
         # sei
         "Ratio of lithium moles to SEI moles": 2.0,
         "SEI partial molar volume [m3.mol-1]": 9.585e-05,

src/pybamm/input/parameters/lithium_ion/OKane2022.py

@@ -508,7 +508,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "lithium_ion",
         # lithium plating
         "Lithium metal partial molar volume [m3.mol-1]": 1.3e-05,
         "Lithium plating kinetic rate constant [m.s-1]": 1e-09,

src/pybamm/input/parameters/lithium_ion/OKane2022_graphite_SiOx_halfcell.py

@@ -392,7 +392,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "lithium_ion",
         # lithium plating
         "Lithium metal partial molar volume [m3.mol-1]": 1.3e-05,
         "Lithium plating kinetic rate constant [m.s-1]": 1e-09,

src/pybamm/input/parameters/lithium_ion/ORegan2022.py

@@ -926,7 +926,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "lithium_ion",
         # cell
         "Negative current collector thickness [m]": 1.2e-05,
         "Negative electrode thickness [m]": 8.52e-05,

src/pybamm/input/parameters/lithium_ion/Prada2013.py

@@ -171,7 +171,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "lithium_ion",
         # cell
         "Negative electrode thickness [m]": 3.4e-05,
         "Separator thickness [m]": 2.5e-05,

src/pybamm/input/parameters/lithium_ion/Ramadass2004.py

@@ -364,7 +364,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "lithium_ion",
         # sei
         "Ratio of lithium moles to SEI moles": 2.0,
         "SEI partial molar volume [m3.mol-1]": 9.585e-05,

src/pybamm/input/parameters/lithium_ion/Xu2019.py

@@ -213,7 +213,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "lithium_ion",
         # sei
         "Ratio of lithium moles to SEI moles": 2.0,
         "SEI partial molar volume [m3.mol-1]": 9.585e-05,

src/pybamm/input/parameters/sodium_ion/Chayambuka2022.py

@@ -278,7 +278,6 @@ def get_parameter_values():
     """
 
     return {
-        "chemistry": "sodium_ion",
         # cell
         "Negative electrode thickness [m]": 64e-6,
         "Separator thickness [m]": 25e-6,

src/pybamm/parameters/parameter_values.py

@@ -25,6 +25,10 @@ class ParameterValues:
         Explicit set of parameters, or reference to an inbuilt parameter set
         If string and matches one of the inbuilt parameter sets, returns that parameter
         set.
+    initial_state_function : function, optional
+        The function to use to set the initial state of the simulation. By default, set to
+        `pybamm.lithium_ion.set_initial_state`, except for the `ECM_Example` parameter set,
+        which is set to `pybamm.equivalent_circuit.set_initial_state`.
 
     Examples
     --------
@@ -38,7 +42,7 @@ class ParameterValues:
 
     """
 
-    def __init__(self, values):
+    def __init__(self, values, initial_state_function=None):
         # add physical constants as default values
         self._dict_items = pybamm.FuzzyDict(
             {
@@ -52,10 +56,25 @@ def __init__(self, values):
         if isinstance(values, dict | ParameterValues):
             # remove the "chemistry" key if it exists
             chemistry = values.pop("chemistry", None)
+            if chemistry == "ecm" and initial_state_function is None:
+                warn(
+                    "The chemistry key is no longer supported. Please use the initial_state_function parameter.",
+                    stacklevel=2,
+                )
+                initial_state_function = pybamm.equivalent_circuit.set_initial_state
+            elif initial_state_function is None:
+                initial_state_function = pybamm.lithium_ion.set_initial_state
             self.update(values, check_already_exists=False)
         else:
             # Check if values is a named parameter set
             if isinstance(values, str) and values in pybamm.parameter_sets.keys():
+                if initial_state_function is None:
+                    if values == "ECM_Example":
+                        initial_state_function = (
+                            pybamm.equivalent_circuit.set_initial_state
+                        )
+                    else:
+                        initial_state_function = pybamm.lithium_ion.set_initial_state
                 values = pybamm.parameter_sets[values]
                 chemistry = values.pop("chemistry", None)
                 self.update(values, check_already_exists=False)
@@ -64,11 +83,7 @@ def __init__(self, values):
                 raise ValueError(
                     f"'{values}' is not a valid parameter set. Parameter set must be one of:\n{valid_sets}"
                 )
-
-        if chemistry == "ecm":
-            self._set_initial_state = pybamm.equivalent_circuit.set_initial_state
-        else:
-            self._set_initial_state = pybamm.lithium_ion.set_initial_state
+        self._set_initial_state = initial_state_function
 
         # Initialise empty _processed_symbols dict (for caching)
         self._processed_symbols = {}

tests/unit/test_parameters/test_base_parameters.py

@@ -33,6 +33,28 @@ def test_getattr__(self):
         assert param.n.cap_init == param.n.Q_init
         assert param.p.prim.cap_init == param.p.prim.Q_init
 
+    def test_that_initial_state_function_is_assigned(self):
+        param_1 = pybamm.ParameterValues("Chen2020")
+        assert param_1._set_initial_state == pybamm.lithium_ion.set_initial_state
+
+        def my_func(x):
+            return x
+
+        param_1 = pybamm.ParameterValues(param_1, initial_state_function=my_func)
+        assert param_1._set_initial_state == my_func
+
+        param_2 = pybamm.ParameterValues("ECM_Example")
+        assert param_2._set_initial_state == pybamm.equivalent_circuit.set_initial_state
+
+        def my_error_func(*args, **kwargs):
+            raise NotImplementedError("this function should error")
+
+        param_1 = pybamm.ParameterValues(param_1, initial_state_function=my_error_func)
+        model = pybamm.lithium_ion.SPM()
+        sim = pybamm.Simulation(model, parameter_values=param_1)
+        with pytest.raises(NotImplementedError, match="this function should error"):
+            sim.solve([0, 1], initial_soc=0.5)
+
     def test__setattr__(self):
         # domain gets added as a subscript
         param = pybamm.GeometricParameters()