Source code for pybamm.models.submodels.interface.sei.base_sei
#
# Base class for SEI models.
#
import pybamm
from pybamm.models.submodels.interface.base_interface import BaseInterface
[docs]
class BaseModel(BaseInterface):
"""Base class for SEI models.
Parameters
----------
param : parameter class
The parameters to use for this submodel
options : dict
A dictionary of options to be passed to the model.
phase : str, optional
Phase of the particle (default is "primary")
cracks : bool, optional
Whether this is a submodel for standard SEI or SEI on cracks
"""
def __init__(self, param, domain, options, phase="primary", cracks=False):
if cracks is True:
reaction = "SEI on cracks"
else:
reaction = "SEI"
super().__init__(param, domain, reaction, options=options, phase=phase)
[docs]
def get_coupled_variables(self, variables):
# Update some common variables
domain, Domain = self.domain_Domain
if self.reaction_loc != "interface":
j_sei_av = variables[
f"X-averaged {domain} electrode {self.reaction_name}interfacial"
" current density [A.m-2]"
]
j_sei = variables[
f"{Domain} electrode {self.reaction_name}interfacial current"
" density [A.m-2]"
]
variables.update(
{
f"X-averaged {domain} electrode {self.reaction_name}interfacial "
"current density [A.m-2]": j_sei_av,
f"{Domain} electrode {self.reaction_name}interfacial current "
"density [A.m-2]": j_sei,
}
)
variables.update(
self._get_standard_volumetric_current_density_variables(variables)
)
return variables
def _get_standard_concentration_variables(self, c_sei):
"""
A private function to obtain the standard variables which
can be derived from the local SEI concentration.
Parameters
----------
c : :class:`pybamm.Symbol`
The SEI concentration.
Returns
-------
variables : dict
The variables which can be derived from the SEI concentration.
"""
domain, Domain = self.domain_Domain
phase_param = self.phase_param
reaction_name = self.reaction_name
if self.reaction_loc == "interface":
# c_sei is an interfacial quantity [mol.m-2]
c_sei_av = pybamm.yz_average(c_sei)
variables = {
f"{Domain} {reaction_name}concentration [mol.m-2]": c_sei,
f"Volume-averaged {domain} {reaction_name}concentration "
"[mol.m-2]": c_sei_av,
}
else:
# c_sei is a bulk quantity [mol.m-3]
if self.size_distribution:
c_sei_sav = pybamm.size_average(c_sei)
c_sei_xav = pybamm.x_average(c_sei_sav)
else:
c_sei_xav = pybamm.x_average(c_sei)
c_sei_av = pybamm.yz_average(c_sei_xav)
variables = {
f"{Domain} {self.reaction_name}concentration [mol.m-3]": c_sei,
f"X-averaged {domain} {reaction_name}concentration "
"[mol.m-3]": c_sei_xav,
f"Volume-averaged {domain} {reaction_name}concentration "
"[mol.m-3]": c_sei_av,
}
# Set scales to one for the "no SEI" model so that they are not required
# by parameter values in general
if isinstance(self, pybamm.sei.NoSEI):
c_sei_0 = 0
c_sei_cr0 = 0
z_sei = 1
else:
L_sei_0 = phase_param.L_sei_0
V_bar_sei = phase_param.V_bar_sei
z_sei = phase_param.z_sei
if self.reaction_loc == "interface":
c_sei_0 = L_sei_0 / V_bar_sei # mol.m-2
else:
c_sei_0 = L_sei_0 * phase_param.a_typ / V_bar_sei # mol.m-3
c_sei_cr0 = phase_param.L_sei_cr0 * phase_param.a_typ / V_bar_sei
if self.reaction == "SEI":
delta_c_sei = c_sei_av - c_sei_0
elif self.reaction == "SEI on cracks":
delta_c_sei = c_sei_av - c_sei_cr0
if self.reaction_loc == "interface":
L_k = 1
elif domain == "negative":
L_k = self.param.n.L
elif domain == "positive":
L_k = self.param.p.L
# Multiply delta_n_SEI by V_k to get total moles of SEI formed
# Multiply by z_sei to get total lithium moles consumed by SEI
V_k = L_k * self.param.L_y * self.param.L_z
Q_sei = delta_c_sei * V_k * z_sei
variables.update(
{
f"Loss of lithium to {domain} {self.reaction_name}[mol]": Q_sei,
f"Loss of capacity to {domain} {self.reaction_name}[A.h]": Q_sei
* self.param.F
/ 3600,
}
)
return variables
def _get_standard_reaction_variables(self, j_sei):
"""
A private function to obtain the standard variables which
can be derived from the SEI interfacial reaction current
Parameters
----------
j_sei : :class:`pybamm.Symbol`
The SEI interfacial reaction current.
Returns
-------
variables : dict
The variables which can be derived from the SEI currents.
"""
domain, Domain = self.domain_Domain
variables = {
f"{Domain} electrode {self.reaction_name}"
"interfacial current density [A.m-2]": j_sei,
}
if self.reaction_loc != "interface":
j_sei_av = pybamm.x_average(j_sei)
variables.update(
{
f"X-averaged {domain} electrode {self.reaction_name}"
"interfacial current density [A.m-2]": j_sei_av,
}
)
return variables
def _get_standard_reaction_distribution_variables(self, j_sei):
"""
A private function to obtain the standard variables which
can be derived from the SEI interfacial reaction current
Parameters
----------
j_sei : :class:`pybamm.Symbol`
The SEI interfacial reaction current.
Returns
-------
variables : dict
The variables which can be derived from the SEI currents.
"""
domain, Domain = self.domain_Domain
j_sei = pybamm.size_average(j_sei)
variables = {
f"{Domain} electrode {self.reaction_name}"
"interfacial current density [A.m-2]": j_sei,
}
if self.reaction_loc != "interface":
j_sei_av = pybamm.x_average(j_sei)
variables.update(
{
f"X-averaged {domain} electrode {self.reaction_name}"
"interfacial current density [A.m-2]": j_sei_av,
}
)
return variables
