BATTERY_THERMAL_RUNAWAY_MODEL

Specifies a thermal runaway model and its parameters.

Type

AcuSolve Command

Syntax

BATTERY_THERMAL_RUNAWAY_MODEL("name") {parameters...}

Parameters

type (enumerated) [NREL_abuse_model]
Type of thermal runaway model.
arc_reaction_model
Fitting of Arrhenius kinetic equations to ARC experimental data.
heat_rate
Direct reading of dT/dt. Can be from ARC or other sources.
NREL_abuse_model

Arrhenius kinetic models for heat release of different cell components based on the NREL thermal runaway model.

equation_type (enumerated) [four_equation]
Type of thermal runaway model.
four_equation
Four equation thermal runaway heat generation model from Hatchard.
five_equation
Hatchard thermal runaway heat generation model (four_equation) with additional heat generation due to electrolyte decomposition.
arc_type (enumerated) [multi_stage_fit]
ARC data fit model.
multi_stage_fit
Parameters for the multi-stage fit of the ARC data.
formulation_type (enumerated) [lumped]
Method used for thermal runaway.
nodal
Thermal runaway heat contribution is calculated at each node in a battery cell.
lumped
Thermal runaway heat contribution is modeled as a lumped parameter for a battery cell.
maximum
Thermal runaway heat contribution is modeled based on the maximum temperature in a battery cell.
ecm_model (enumerated) [yes]
Turn on ecm model for thermal runaway.
yes
Model thermal runaway heat generation with an ECM model included for the batteries operating under normal conditions.
no
Model only thermal runaway heat generation.
internal_short_circuit (enumerated) [off]
Add internal short circuit equation to thermal runaway model.
off
Internal short circuit equation is disabled.
on
Internal short circuit equation is enabled.
internal_short_circuit_model (enumerated) [simple]
Choose different equation to model internal short circuit.
simple
Simpler model does not include consumption of anode and cathode material, from Coman 2017.
internal_short_circuit_temperature (real) [=438.15]
Temperature at which internal short circuit occurs.
sub_iteration_initial_time_step_size (real) [=1000]
Initial time step for sub-stepping the reaction kinetic equation.
sub_iteration_minimum_time_step_size (real) [=1e-4]
Minimum time step for sub-stepping the reaction kinetic equations.
sub_iteration_time_step_size_tolerance (real) [=1e-3]
Sensitivity of the change in sub-step time step size to changes in the solution. For example, a small tolerance value will lead to smaller thermal runaway ODE sub-stepping time step sizes.
sub_iteration_time_step_size_factor (real) [=0.1]
Factor to time with tolerance and minimum time step size for SOC equation.
anode_decomposition_frequency_factor (real) [=2.5e13]
Pre-exponential (frequency) factor for the anode decomposition reaction rate.
sei_decomposition_frequency_factor (real) [=1.67e15]
Pre-exponential (frequency) factor for the sei (solid electrolyte interphase) decomposition reaction rate.
cathode_decomposition_frequency_factor (real) [=6.67e11]
Pre-exponential (frequency) factor for the cathode decomposition reaction rate.
electrochemical_reactions_frequency_factor (real) [=3.37e12]
Pre-exponential (frequency) factor for the electrochemical reaction rate.
electrolyte_decomposition_frequency_factor (real) [=5.14e25]
Pre-exponential (frequency) factor for the electrolyte decomposition reaction rate.
anode_decomposition_activation_energy (real) [=2.24e-19]
Minimum energy needed for the anode decomposition reaction to occur.
sei_decomposition_activation_energy (real) [=2.24e-19]
Minimum energy needed for the sei decomposition reaction to occur.
cathode_decomposition_activation_energy (real) [=2.03e-19]
Minimum energy needed for the cathode decomposition reaction to occur.
electrochemical_reactions_activation_energy (real) [=1.58e-19]
Minimum energy needed for the electrochemical (short circuit) reaction to occur.
electrolyte_decomposition_activation_energy (real) [=4.544e-19]
Minimum energy needed for the electrolyte decomposition reaction to occur.
mass_type (real) [=specific]
Specify total or specific mass (mass/volume) of the jellyroll.
specific
Specific mass (Kg/m^3).
total
Total mass (Kg).
anode_mass (real) [=0.006]
Mass of the anode material in battery core.
cathode_mass (real) [=0.012]
Mass of the cathode material in battery core.
sei_mass (real) [=0.006]
Mass of the sei in battery core.
electrolyte_mass (real) [=0.004]
Mass of the electrolyte in battery core.
anode_decomposition_reaction_enthalpy (real) [=1.714E6]
Specific enthalpy for the anode decomposition reaction.
cathode_decomposition_reaction_enthalpy (real) [=3.14E5]
Specific enthalpy for the cathode decomposition reaction.
sei_decomposition_reaction_enthalpy (real) [=2.57E5]
Specific enthalpy for the sei decomposition reaction.
electrochemical_reaction_enthalpy_type (enumerated) [=value]
value
Input enthalpy value directly.
calculate
Calculate enthalpy value based on ECM output voltage or maximum cell voltage (if ECM is off).
electrochemical_reaction_enthalpy (real) [=4.989E6]
Enthalpy of the short circuit derived from joule heating.
electrolyte_decomposition_reaction_enthalpy (real) [=1.55E5]
Specific enthalpy for the electrolyte decomposition reaction.
initial_anode_lithium_fraction (real) [=0.75]
Fractional amount of lithium intercalated in the anode.
initial_sei_lithium_fraction (real) [=0.15]
Fraction of lithium-containing species in the solid electrolyte interphase.
initial_sei_thickness (real) [=0.033]
Thickness of the solid electrolyte interphase.
initial_degree_of_cathode_conversion (real) [=0.04]
Initial degree of conversion of cathode material for cathode decomposition.
initial_electrolyte_fraction (real) [=1.0]
Initial electrolyte fraction.
heat_rate_type (enumerated) [=none]
Type ARC experimental data fitting.
none
No ARC data specified.
piecewise_linear or linear
Piecewise linear curve fit of ARC experimental data.
cubic_spline or spline
Cubic spline curve fit of ARC experimental data.
heat_rate_curve_fit_values (array) [={0,0}]
A two-column array of heat rate (dT/dt) data values. The independent variable must be temperature. Used with piecewise_linear and cubic_spline types.
heat_rate_curve_fit_variable (enumerated) [=temperature]
Independent variable of the curve fit of ARC experimental data. Used with piecewise_linear and cubic_spline types.
temperature
temperature
heat_rate_max_temperature (real) [=700]
Maximum cell temperature recorded during the ARC experiment.
heat_rate_trigger_temperature (real) [=500]
Trigger temperature for thermal runaway recorded during the ARC experiment. At or above this temperature the ARC data is sub-stepped in time for improved accuracy.
heat_rate_onset_temperature (real) [=373.15]
Thermal runaway self-heating onset temperature recorded during the ARC experiment. At or above this temperature the ARC data model is enabled.
parameter_fit_type (arrhenius) [=none]
Type of Arrhenius kinetic parameter fitting approach.
arrhenius
Arrhenius kinetics fitted to each stage and active throughout.
arrhenius_trigger
Arrhenius kinetics fitted to each stage. Final stage heat only active following a trigger temperature.
multi_stage_model_parameters (array) [={}]
An N rows times six-column array of enthalpy (J); activation energy (J); frequency factor (1/s); reaction order n (-); and reaction order m (-); and initial condition (-) values. Each row of the array represents a specific stage (up to five).