fix degradation options when one of the phases has no degradation (py…

…bamm-team#4163)

* fix degradation options when one of the phases has no degradation

* skip Newman Tobias test

---------

Co-authored-by: Eric G. Kratz <kratman@users.noreply.github.com>
Co-authored-by: Arjun Verma <arjunverma.oc@gmail.com>

pybamm/models/full_battery_models/lithium_ion/base_lithium_ion_model.py

@@ -265,9 +265,9 @@ def set_sei_submodel(self):
                 reaction_loc = "x-average"
             else:
                 reaction_loc = "full electrode"
-            sei_option = getattr(self.options, domain)["SEI"]
             phases = self.options.phases[domain]
             for phase in phases:
+                sei_option = getattr(getattr(self.options, domain), phase)["SEI"]
                 if sei_option == "none":
                     submodel = pybamm.sei.NoSEI(self.param, domain, self.options, phase)
                 elif sei_option == "constant":
@@ -333,9 +333,11 @@ def set_lithium_plating_submodel(self):
         for domain in self.options.whole_cell_domains:
             if domain != "separator":
                 domain = domain.split()[0].lower()
-                lithium_plating_opt = getattr(self.options, domain)["lithium plating"]
                 phases = self.options.phases[domain]
                 for phase in phases:
+                    lithium_plating_opt = getattr(getattr(self.options, domain), phase)[
+                        "lithium plating"
+                    ]
                     if lithium_plating_opt == "none":
                         submodel = pybamm.lithium_plating.NoPlating(
                             self.param, domain, self.options, phase

pybamm/models/submodels/active_material/loss_active_material.py

@@ -60,7 +60,9 @@ def get_coupled_variables(self, variables):
         domain, Domain = self.domain_Domain
 
         deps_solid_dt = 0
-        lam_option = getattr(self.options, self.domain)["loss of active material"]
+        lam_option = getattr(getattr(self.options, domain), self.phase)[
+            "loss of active material"
+        ]
         if "stress" in lam_option:
             # obtain the rate of loss of active materials (LAM) by stress
             # This is loss of active material model by mechanical effects

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

@@ -559,3 +559,28 @@ def test_well_posed_composite_diffusion_hysteresis(self):
             "open-circuit potential": (("current sigmoid", "single"), "single"),
         }
         self.check_well_posedness(options)
+
+    def test_well_posed_composite_different_degradation(self):
+        # phases have same degradation
+        options = {
+            "particle phases": ("2", "1"),
+            "SEI": ("ec reaction limited", "none"),
+            "lithium plating": ("reversible", "none"),
+            "open-circuit potential": (("current sigmoid", "single"), "single"),
+        }
+        self.check_well_posedness(options)
+        # phases have different degradation
+        options = {
+            "particle phases": ("2", "1"),
+            "SEI": (("ec reaction limited", "solvent-diffusion limited"), "none"),
+            "lithium plating": (("reversible", "irreversible"), "none"),
+            "open-circuit potential": (("current sigmoid", "single"), "single"),
+        }
+        self.check_well_posedness(options)
+        # one of the phases has no degradation
+        options = {
+            "particle phases": ("2", "1"),
+            "SEI": (("none", "solvent-diffusion limited"), "none"),
+            "lithium plating": (("none", "irreversible"), "none"),
+        }
+        self.check_well_posedness(options)

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

@@ -35,3 +35,7 @@ def test_well_posed_composite_kinetic_hysteresis(self):
     @pytest.mark.skip(reason="Test currently not implemented")
     def test_well_posed_composite_diffusion_hysteresis(self):
         pass  # skip this test
+
+    @pytest.mark.skip(reason="Test currently not implemented")
+    def test_well_posed_composite_different_degradation(self):
+        pass  # skip this test