Crossover and degradation checks

src/rfbzero/experiment.py

@@ -1,7 +1,7 @@
 """
 Classes to define electrochemical cycling protocols.
 """
-
+import copy
 from abc import ABC, abstractmethod
 from enum import Enum
 from typing import Callable, Optional
@@ -524,13 +524,19 @@ def _validate_protocol(
         if cell_model.init_ocv > 0.0 > self.voltage_limit_discharge:
             raise ValueError("Ensure that 'voltage_limit_discharge' >= 0.0 when 'init_ocv' > 0.0")
 
+        if crossover and cell_model.init_ocv > 0.0:
+            raise ValueError("Cannot use crossover mechanism for a full cell ('init_ocv' > 0.0)")
+
         if degradation is not None and (cls_degradation is not None or ncls_degradation is not None):
             raise ValueError("Cannot specify both 'degradation' and '(n)cls_degradation'")
 
         if degradation is not None:
             cls_degradation = degradation
             ncls_degradation = degradation
 
+        cls_degradation = copy.deepcopy(cls_degradation)
+        ncls_degradation = copy.deepcopy(ncls_degradation)
+
         if cell_model.negative_concentrations():
             raise ValueError('Negative concentration detected')
 

tests/test_experiment.py

@@ -107,15 +107,54 @@ def test_cv1(self):
 
 class TestConstantCurrentConstantVoltage:
 
-    def test_cccv(self):
-        # define the battery design parameters
+    def test_cccv_full_cell(self):
+        with pytest.raises(ValueError):
+            cell = ZeroDModel(cls_volume=0.005,  # L
+                              ncls_volume=0.03,  # L
+                              cls_start_c_ox=0.01,  # M
+                              cls_start_c_red=0.01,  # M
+                              ncls_start_c_ox=0.01,  # M
+                              ncls_start_c_red=0.01,  # M
+                              init_ocv=1.1,  # V
+                              resistance=0.8,  # ohms
+                              k_0_cls=1e-3,  # cm/s
+                              k_0_ncls=1e-3,  # cm/s
+                              n_cls=1,  # electrons
+                              n_ncls=1,  # electrons
+                              )
+
+            # define degradation mechanisms
+            deg1 = ChemicalDegradation(rate_order=2, rate_constant=5e-5, species='red')
+
+            deg2 = AutoOxidation(rate_constant=1e-4)
+
+            # define crossover mechanisms
+            cross = Crossover(membrane_thickness=183, permeability_ox=5e-6, permeability_red=2e-6)
+
+            # define cycling protocol
+            protocol = ConstantCurrentConstantVoltage(
+                voltage_limit_charge=1.45,
+                voltage_limit_discharge=0.8,
+                current_cutoff_charge=0.005,
+                current_cutoff_discharge=-0.005,
+                current=0.1
+            )
+
+            # putting it all together
+            all_results = protocol.run(cell_model=cell,
+                                       duration=1000,  # cycle time to simulate (s)
+                                       degradation=MultiDegradationMechanism([deg1, deg2]),
+                                       crossover=cross,
+                                       )
+
+    def test_cccv_symmetric_cell(self):
         cell = ZeroDModel(cls_volume=0.005,  # L
                           ncls_volume=0.03,  # L
                           cls_start_c_ox=0.01,  # M
                           cls_start_c_red=0.01,  # M
                           ncls_start_c_ox=0.01,  # M
                           ncls_start_c_red=0.01,  # M
-                          init_ocv=1.1,  # V
+                          init_ocv=0.0,  # V
                           resistance=0.8,  # ohms
                           k_0_cls=1e-3,  # cm/s
                           k_0_ncls=1e-3,  # cm/s
@@ -133,11 +172,11 @@ def test_cccv(self):
 
         # define cycling protocol
         protocol = ConstantCurrentConstantVoltage(
-            voltage_limit_charge=1.45,
-            voltage_limit_discharge=0.8,
+            voltage_limit_charge=0.25,
+            voltage_limit_discharge=-0.2,
             current_cutoff_charge=0.005,
             current_cutoff_discharge=-0.005,
-            current=0.1
+            current=0.12
         )
 
         # putting it all together
@@ -146,10 +185,9 @@ def test_cccv(self):
                                    degradation=MultiDegradationMechanism([deg1, deg2]),
                                    crossover=cross,
                                    )
-        expected = [4.898116190603088, 9.622472024194355, 9.719800105349496, 9.622272591351388, 9.725092303584894]
+
+        expected = [4.887409109362002, 9.616027334885318, 9.695579899478137, 9.614489292146322, 9.69754666694821]
         vals = all_results.half_cycle_capacity[:5]
         assert np.isclose(vals, expected).all()
 
 
-
-