RCAIDE.Library.Components.Powertrain.Sources.Battery_Modules.Lithium_Ion_LFP

Lithium_Ion_LFP#

class Lithium_Ion_LFP(*args, **kwarg)[source]#

Bases: Generic_Battery_Module

Class for modeling A123 26650 lithium iron phosphate battery characteristics

tag#

Identifier for the battery module (default: ‘lithium_ion_lfp’)

Type:

str

power_split_ratio#

Power distribution ratio for multiple battery systems

Type:

float, optional

number_of_cells#

Number of cells in the module (default: 1)

Type:

int

maximum_energy#

Maximum energy storage capacity [J] (default: 0.0)

Type:

float

maximum_power#

Maximum power output [W] (default: 0.0)

Type:

float

maximum_voltage#

Maximum voltage output [V] (default: 0.0)

Type:

float

cell#
Cell-specific properties
  • chemistrystr

    Battery chemistry type (default: ‘LiFePO4’)

  • diameterfloat

    Cell diameter [m] (default: 0.0185)

  • heightfloat

    Cell height [m] (default: 0.0653)

  • massfloat

    Cell mass [kg] (default: 0.03)

  • surface_areafloat

    Total cell surface area [m^2]

  • volumefloat

    Cell volume [m^3]

  • densityfloat

    Cell density [kg/m^3]

  • electrode_areafloat

    Active electrode area [m^2] (default: 0.0342)

  • maximum_voltagefloat

    Maximum cell voltage [V] (default: 3.6)

  • nominal_capacityfloat

    Rated capacity [Ah] (default: 2.6)

  • nominal_voltagefloat

    Nominal operating voltage [V] (default: 3.6)

  • resistancefloat

    Internal resistance [Ohms] (default: 0.022)

  • specific_heat_capacityfloat

    Cell specific heat [J/kgK] (default: 1115)

  • radial_thermal_conductivityfloat

    Radial thermal conductivity [W/mK] (default: 0.475)

  • axial_thermal_conductivityfloat

    Axial thermal conductivity [W/mK] (default: 37.6)

  • discharge_performance_mapNearestNDInterpolator

    Interpolator for voltage vs discharge characteristics

Type:

Data

Notes

The LFP cell model includes detailed thermal and electrical characteristics based on the A123 26650 cell. Performance data is interpolated from experimental measurements.

References

[1] LithiumWerks (2019).A123 26650 Datasheet

https://a123batteries.com/product_images/uploaded_images/26650.pdf

[2] Arora, S., & Kapoor, A. (2019). Experimental Study of Heat Generation

Rate during Discharge of LiFePO4 Pouch Cells. Batteries, 5(4), 70. https://doi.org/10.3390/batteries5040070

See also

RCAIDE.Library.Components.Powertrain.Sources.Battery_Modules.Generic_Battery_Module

Base battery module class

energy_calc(state, bus, coolant_lines, t_idx, delta_t)[source]#

Computes the state of the LFP battery cell

Parameters:

  • state (Data) – Current system state

  • bus (Component) – Connected electrical bus

  • coolant_lines (Component) – Connected cooling system

  • t_idx (int) – Time index

  • delta_t (float) – Time step [s]

Returns:

  • stored_results_flag (bool) – Flag indicating if results were stored

  • stored_battery_tag (str) – Identifier for stored results

reuse_stored_data(state, bus, stored_results_flag, stored_battery_tag)[source]#

Reuses previously stored battery performance data

Parameters:

  • state (Data) – Current system state

  • bus (Component) – Connected electrical bus

  • coolant_lines (Component) – Connected cooling system

  • t_idx (int) – Time index

  • delta_t (float) – Time step [s]

  • stored_results_flag (bool) – Flag indicating stored results exist

  • stored_battery_tag (str) – Identifier for stored results

update_battery_age(segment, battery_conditions, increment_battery_age_by_one_day)[source]#

Updates battery age and degradation parameters

Parameters:

  • segment (Segment) – Flight segment data

  • battery_conditions (Data) – Battery operating conditions

  • increment_battery_age_by_one_day (bool) – Flag to increment battery age

create_discharge_performance_map(raw_data)[source]#

Creates an interpolator for battery discharge voltage characteristics

This function processes raw battery test data to create an interpolation function that predicts battery voltage based on C-rate, temperature, and discharge capacity.

Parameters:

raw_data (dict) – Dictionary containing battery test data with structure: {c_rate: {temperature: {‘discharge’: […], ‘voltage’: […]}}}

Returns:

battery_data – Interpolator function that takes [C-rate, temperature, discharge_capacity] and returns voltage

Return type:

NearestNDInterpolator

Notes

The function creates a 3D interpolation of voltage as a function of: - C-rate (discharge current relative to capacity) - Temperature - Discharge capacity (state of charge)

Uses nearest neighbor interpolation for computational efficiency. Linear interpolation is possible but increases computation time by ~30x.

References

[1] Lin, X., Perez, H., Siegel, J. B., & Stefanopoulou, A. G. (2024).

“An Electro-Thermal Model for the A123 26650 LiFePO4 Battery.” University of Michigan. https://hdl.handle.net/2027.42/97341

load_battery_results()[source]#

Load experimental raw data of LFP cells

Assumptions:

Source:

Parameters:

None

Returns:

raw data from battery [unitless]

Return type:

battery_data