Merge pull request #2719 from DrSOKane/current-sigmoid

Changed current_sigmoid_ocp to be valid for both electrodes

Author: valentinsulzer

CHANGELOG.md

@@ -8,6 +8,7 @@
 
 ## Bug fixes
 
+- Fixed current_sigmoid_ocp to be valid for both electrodes ([#2719](https://github.com/pybamm-team/PyBaMM/pull/2719)).
 - Fixed the length scaling for the first dimension of r-R plots ([#2663](https://github.com/pybamm-team/PyBaMM/pull/2663)).
 
 # [v23.1](https://github.com/pybamm-team/PyBaMM/tree/v23.1) - 2023-01-31

examples/notebooks/models/composite_particle.ipynb

@@ -91,7 +91,6 @@
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "10339d40",
    "metadata": {},
@@ -594,7 +593,6 @@
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "dbc0edb2",
    "metadata": {},
@@ -639,7 +637,6 @@
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "40467b70",
    "metadata": {},
@@ -849,7 +846,6 @@
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "977b4c09",
    "metadata": {},
@@ -935,7 +931,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "dev",
+   "display_name": "Python 3 (ipykernel)",
    "language": "python",
    "name": "python3"
   },
@@ -949,7 +945,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.6"
+   "version": "3.8.10"
   },
   "toc": {
    "base_numbering": 1,

pybamm/models/submodels/interface/open_circuit_potential/current_sigmoid_ocp.py

@@ -7,12 +7,18 @@
 
 class CurrentSigmoidOpenCircuitPotential(BaseOpenCircuitPotential):
     def get_coupled_variables(self, variables):
+        domain, Domain = self.domain_Domain
         current = variables["Total current density"]
         k = 100
-        m_lith = pybamm.sigmoid(current, 0, k)  # for lithation (current < 0)
-        m_delith = 1 - m_lith  # for delithiation (current > 0)
 
-        domain, Domain = self.domain_Domain
+        if Domain == "Positive":
+            lithiation_current = current
+        elif Domain == "Negative":
+            lithiation_current = -current
+
+        m_lith = pybamm.sigmoid(0, lithiation_current, k)  # lithiation_current > 0
+        m_delith = 1 - m_lith  # lithiation_current < 0
+
         phase_name = self.phase_name
 
         if self.reaction == "lithium-ion main":