PyBaMM Version

develop branch

Python Version

3.10.12

Describe the bug

If the "particle mechanics" option is enabled on either electrode, the "stress-induced diffusion" option is enabled on both, unless otherwise specified. See the example below, where the voltage is much lower if stress-induced diffusion is explicitly disabled in the positive electrode.

I can add some code to base_battery_model to fix this, but I'm aware that code has to handle a lot of complex cases already so not sure how to proceed...

Steps to Reproduce

import pybamm
import matplotlib.pyplot as plt
model1 = pybamm.lithium_ion.DFN({"particle mechanics": ("swelling only", "none")})
param = pybamm.ParameterValues("OKane2022")
exp = pybamm.Experiment(["Discharge at 1C until 2.5 V"])
sim1 = pybamm.Simulation(model1, parameter_values=param, experiment=exp)
sol1 = sim1.solve()
model2 = pybamm.lithium_ion.DFN({"particle mechanics": ("none", "swelling only")})
sim2 = pybamm.Simulation(model2, parameter_values=param, experiment=exp)
sol2 = sim2.solve()
model3 = pybamm.lithium_ion.DFN(
{
"particle mechanics": ("swelling only", "none"),
"stress-induced diffusion": ("true", "false"),
}
)
sim3 = pybamm.Simulation(model3, parameter_values=param, experiment=exp)
sol3 = sim3.solve()
model4 = pybamm.lithium_ion.DFN(
{
"particle mechanics": ("none", "swelling only"),
"stress-induced diffusion": ("false", "true"),
}
)
sim4 = pybamm.Simulation(model4, parameter_values=param, experiment=exp)
sol4 = sim4.solve()
Q1 = sol1["Discharge capacity [A.h]"].data
V1 = sol1["Voltage [V]"].data
Q2 = sol2["Discharge capacity [A.h]"].data
V2 = sol2["Voltage [V]"].data
Q3 = sol3["Discharge capacity [A.h]"].data
V3 = sol3["Voltage [V]"].data
Q4 = sol4["Discharge capacity [A.h]"].data
V4 = sol4["Voltage [V]"].data
plt.figure()
plt.plot(Q1,V1,label="model1")
plt.plot(Q2,V2,label="model2",linestyle="dashed")
plt.plot(Q3,V3,label="model3",linestyle="dotted")
plt.plot(Q4,V4,label="model4",linestyle="dashdot")
plt.legend()
plt.show()

Relevant log output