Electrode SOH models

class pybamm.lithium_ion.ElectrodeSOH(name='Electrode-specific SOH model')

Model to calculate electrode-specific SOH, from [1]. This model is mainly for internal use, to calculate summary variables in a simulation.

\[n_{Li} = \frac{3600}{F}(y_{100}C_p + x_{100}C_n),\]

\[V_{max} = U_p(y_{100}) - U_n(x_{100}),\]

\[V_{min} = U_p(y_{0}) - U_n(x_{0}),\]

\[x_0 = x_{100} - \frac{C}{C_n},\]

\[y_0 = y_{100} + \frac{C}{C_p}.\]

References

[1]	Mohtat, P., Lee, S., Siegel, J. B., & Stefanopoulou, A. G. (2019). Towards better estimability of electrode-specific state of health: Decoding the cell expansion. Journal of Power Sources, 427, 101-111.

Extends: pybamm.BaseModel

default_solver

Return default solver based on whether model is ODE/DAE or algebraic

class pybamm.lithium_ion.ElectrodeSOHHalfCell(working_electrode, name='Electrode-specific SOH model')

Model to calculate electrode-specific SOH for a half-cell, adapted from [2]. This model is mainly for internal use, to calculate summary variables in a simulation.

\[V_{max} = U_w(x_{100}),\]

\[V_{min} = U_w(x_{0}),\]

\[x_0 = x_{100} - \frac{C}{C_w}.\]

Subscript w indicates working electrode and subscript c indicates counter electrode.

References

[2]	Mohtat, P., Lee, S., Siegel, J. B., & Stefanopoulou, A. G. (2019). Towards better estimability of electrode-specific state of health: Decoding the cell expansion. Journal of Power Sources, 427, 101-111.

Extends: pybamm.BaseModel

default_solver

Return default solver based on whether model is ODE/DAE or algebraic

new_empty_copy()

Create an empty copy of the model with the same name and “parameters” (convert_to_format, etc), but empty equations and variables. This is usually then called by pybamm.ParameterValues, pybamm.Discretisation, or pybamm.SymbolReplacer.

pybamm.lithium_ion.get_initial_stoichiometries(initial_soc, parameter_values)

Calculate initial stoichiometries to start off the simulation at a particular state of charge, given voltage limits, open-circuit potentials, etc defined by parameter_values

Parameters:

• initial_soc (float) – Target initial SOC. Must be between 0 and 1.
• parameter_values (pybamm.ParameterValues) – The parameter values class that will be used for the simulation. Required for calculating appropriate initial stoichiometries.

Returns:

The initial stoichiometries that give the desired initial state of charge

Return type:

x, y