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

property 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

property 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