Dynamic Analysis Controls¶

In this notebook we demonstrate the optional dynamic-analysis controls available through breathe_simulate. The first example is an anode potential controlled charge example, while the other examples include a charge sequence followed by a 2C discharge so the charge and discharge behaviour can be reviewed in the same simulation.

In [1]:

from breathe_simulate import api_interface as api
from breathe_simulate import enable_notebook_plotly

enable_notebook_plotly()

from breathe_simulate import api_interface as api from breathe_simulate import enable_notebook_plotly enable_notebook_plotly()

We start from the baseline Molicel P45B cell and define one shared set of operating conditions so every example can be compared directly.

In [2]:

base_battery = "Molicel P45B"
eqm_results = api.get_eqm_kpis(base_battery)
capacity_ah = eqm_results.capacity

initial_soc = 0.2
initial_temperature_degC = 25.0
ambient_temperature_degC = 25.0
charge_2c_A = 2.0 * capacity_ah
charge_1p2c_A = 1.2 * capacity_ah
charge_0p6c_A = 0.6 * capacity_ah
discharge_2c_A = 2.0 * capacity_ah

plot_variables = [
    "Charge current [A]",
    "Voltage [V]",
    "Cell temperature [°C]",
    "SoC",
    "Anode voltage [V]",
]

capacity_ah

base_battery = "Molicel P45B" eqm_results = api.get_eqm_kpis(base_battery) capacity_ah = eqm_results.capacity initial_soc = 0.2 initial_temperature_degC = 25.0 ambient_temperature_degC = 25.0 charge_2c_A = 2.0 * capacity_ah charge_1p2c_A = 1.2 * capacity_ah charge_0p6c_A = 0.6 * capacity_ah discharge_2c_A = 2.0 * capacity_ah plot_variables = [ "Charge current [A]", "Voltage [V]", "Cell temperature [°C]", "SoC", "Anode voltage [V]", ] capacity_ah

Out[2]:

np.float64(4.499999999999997)

Anode potential limited CC_CHG charge¶

The charge phase uses an anode-potential threshold, causing the current to automatically derate if the anode potential reaches the specified limit.

In [3]:

anode_limited_cycle = {
    "cycle_type": "CC_CHG",
    "selected_unit": "C",
    "control_parameters": {
        "I_chg": 2,
        "V_max": 4.2,
        "anode_potential_threshold_mV": 50.0,
    },
}

anode_limited_output = api.run_sim(
    base_battery=base_battery,
    cycler=anode_limited_cycle,
    designs=[],
    initialSoC=initial_soc,
    initialTemperature_degC=initial_temperature_degC,
    ambientTemperature_degC=ambient_temperature_degC,
)

anode_limited_output.plot_dynamic_response(plot_variables)

anode_limited_cycle = { "cycle_type": "CC_CHG", "selected_unit": "C", "control_parameters": { "I_chg": 2, "V_max": 4.2, "anode_potential_threshold_mV": 50.0, }, } anode_limited_output = api.run_sim( base_battery=base_battery, cycler=anode_limited_cycle, designs=[], initialSoC=initial_soc, initialTemperature_degC=initial_temperature_degC, ambientTemperature_degC=ambient_temperature_degC, ) anode_limited_output.plot_dynamic_response(plot_variables)

Anode potential limited CCCV charge followed by rest and a 2C discharge¶

The charge phase uses an anode-potential threshold so the current derates if the anode potential reaches the limit.

In [4]:

anode_limited_cycle = {
    "cycle_type": "CCCV",
    "selected_unit": "C",
    "control_parameters": {
        "I_chg": 2.0,
        "I_dch": -2.0,
        "I_cut": 0.05,
        "V_max": 4.2,
        "V_min": 3.1,
        "t_restC": 600.0,
        "t_restD": 600.0,
        "anode_potential_threshold_mV": 50.0,
    },
}

anode_limited_output = api.run_sim(
    base_battery=base_battery,
    cycler=anode_limited_cycle,
    designs=[],
    initialSoC=initial_soc,
    initialTemperature_degC=initial_temperature_degC,
    ambientTemperature_degC=ambient_temperature_degC,
)

anode_limited_output.plot_dynamic_response(plot_variables)

anode_limited_cycle = { "cycle_type": "CCCV", "selected_unit": "C", "control_parameters": { "I_chg": 2.0, "I_dch": -2.0, "I_cut": 0.05, "V_max": 4.2, "V_min": 3.1, "t_restC": 600.0, "t_restD": 600.0, "anode_potential_threshold_mV": 50.0, }, } anode_limited_output = api.run_sim( base_battery=base_battery, cycler=anode_limited_cycle, designs=[], initialSoC=initial_soc, initialTemperature_degC=initial_temperature_degC, ambientTemperature_degC=ambient_temperature_degC, ) anode_limited_output.plot_dynamic_response(plot_variables)

Temperature limited CCCV charge followed by a rest and a 2C discharge¶

The charge phase uses a temperature threshold so the current derates if the cell temperature reaches the limit.

In [5]:

temperature_limited_cycle = {
    "cycle_type": "CCCV",
    "selected_unit": "C",
    "control_parameters": {
        "I_chg": 2.0,
        "I_dch": -2.0,
        "I_cut": 0.05,
        "V_max": 4.2,
        "V_min": 3.1,
        "t_restC": 600.0,
        "t_restD": 600.0,
        "temperature_threshold_K": 303.15,
    },
}

temperature_limited_output = api.run_sim(
    base_battery=base_battery,
    cycler=temperature_limited_cycle,
    designs=[],
    initialSoC=initial_soc,
    initialTemperature_degC=initial_temperature_degC,
    ambientTemperature_degC=ambient_temperature_degC,
)

temperature_limited_output.plot_dynamic_response(plot_variables)

temperature_limited_cycle = { "cycle_type": "CCCV", "selected_unit": "C", "control_parameters": { "I_chg": 2.0, "I_dch": -2.0, "I_cut": 0.05, "V_max": 4.2, "V_min": 3.1, "t_restC": 600.0, "t_restD": 600.0, "temperature_threshold_K": 303.15, }, } temperature_limited_output = api.run_sim( base_battery=base_battery, cycler=temperature_limited_cycle, designs=[], initialSoC=initial_soc, initialTemperature_degC=initial_temperature_degC, ambientTemperature_degC=ambient_temperature_degC, ) temperature_limited_output.plot_dynamic_response(plot_variables)

Combined anode potential and temperature limited CCCV charge followed by a rest and a 2C discharge¶

The charge phase can enforce both anode-potential and temperature limits at the same time.

In [6]:

combined_threshold_cycle = {
    "cycle_type": "CCCV",
    "selected_unit": "C",
    "control_parameters": {
        "I_chg": 2.0,
        "I_dch": -2.0,
        "I_cut": 0.05,
        "V_max": 4.2,
        "V_min": 3.1,
        "t_restC": 600.0,
        "t_restD": 600.0,
        "anode_potential_threshold_mV": 50.0,
        "temperature_threshold_K": 303.15,
    },
}

combined_threshold_output = api.run_sim(
    base_battery=base_battery,
    cycler=combined_threshold_cycle,
    designs=[],
    initialSoC=initial_soc,
    initialTemperature_degC=initial_temperature_degC,
    ambientTemperature_degC=ambient_temperature_degC,
)

combined_threshold_output.plot_dynamic_response(plot_variables)

combined_threshold_cycle = { "cycle_type": "CCCV", "selected_unit": "C", "control_parameters": { "I_chg": 2.0, "I_dch": -2.0, "I_cut": 0.05, "V_max": 4.2, "V_min": 3.1, "t_restC": 600.0, "t_restD": 600.0, "anode_potential_threshold_mV": 50.0, "temperature_threshold_K": 303.15, }, } combined_threshold_output = api.run_sim( base_battery=base_battery, cycler=combined_threshold_cycle, designs=[], initialSoC=initial_soc, initialTemperature_degC=initial_temperature_degC, ambientTemperature_degC=ambient_temperature_degC, ) combined_threshold_output.plot_dynamic_response(plot_variables)

Step charge with SoC setpoints followed by a 2C discharge with SoC setpoints. Uses CUSTOM cycler type¶

This custom profile changes current when SoC milestones are reached during charge, then uses a 2C discharge step that also ends on an SoC target.

In [7]:

soc_step_cycle = {
    "cycle_type": "CUSTOM",
    "selected_unit": "A",
    "control_parameters": {
        "experiment_text": [
            {
                "type": "soc_current_profile",
                "steps": [
                    {
                        "type": "soc_current",
                        "mode": "charge",
                        "current_a": charge_2c_A,
                        "until_soc": 0.40,
                    },
                    {
                        "type": "soc_current",
                        "mode": "charge",
                        "current_a": charge_1p2c_A,
                        "until_soc": 0.60,
                    },
                    {
                        "type": "soc_current",
                        "mode": "charge",
                        "current_a": charge_0p6c_A,
                        "until_soc": 0.80,
                    },
                    {
                        "type": "soc_current",
                        "mode": "discharge",
                        "current_a": discharge_2c_A,
                        "until_soc": 0.20,
                    },
                ],
            }
        ],
        "period": "1s",
    },
}

soc_step_output = api.run_sim(
    base_battery=base_battery,
    cycler=soc_step_cycle,
    designs=[],
    initialSoC=initial_soc,
    initialTemperature_degC=initial_temperature_degC,
    ambientTemperature_degC=ambient_temperature_degC,
)

soc_step_output.plot_dynamic_response(plot_variables)

soc_step_cycle = { "cycle_type": "CUSTOM", "selected_unit": "A", "control_parameters": { "experiment_text": [ { "type": "soc_current_profile", "steps": [ { "type": "soc_current", "mode": "charge", "current_a": charge_2c_A, "until_soc": 0.40, }, { "type": "soc_current", "mode": "charge", "current_a": charge_1p2c_A, "until_soc": 0.60, }, { "type": "soc_current", "mode": "charge", "current_a": charge_0p6c_A, "until_soc": 0.80, }, { "type": "soc_current", "mode": "discharge", "current_a": discharge_2c_A, "until_soc": 0.20, }, ], } ], "period": "1s", }, } soc_step_output = api.run_sim( base_battery=base_battery, cycler=soc_step_cycle, designs=[], initialSoC=initial_soc, initialTemperature_degC=initial_temperature_degC, ambientTemperature_degC=ambient_temperature_degC, ) soc_step_output.plot_dynamic_response(plot_variables)

Step charge with voltage setpoints followed by 2C discharge with voltage setpoints. Uses CUSTOM cycler type¶

This custom profile changes current when voltage thresholds are reached during charge, then uses a 2C discharge step that ends on a voltage cut-off.

In [8]:

voltage_step_cycle = {
    "cycle_type": "CUSTOM",
    "selected_unit": "A",
    "control_parameters": {
        "experiment_text": [
            {
                "type": "step_current_profile",
                "steps": [
                    {
                        "type": "step_current",
                        "mode": "charge",
                        "current_a": charge_2c_A,
                        "until_voltage_v": 3.80,
                    },
                    {
                        "type": "step_current",
                        "mode": "charge",
                        "current_a": charge_1p2c_A,
                        "until_voltage_v": 4.00,
                    },
                    {
                        "type": "step_current",
                        "mode": "charge",
                        "current_a": charge_0p6c_A,
                        "until_voltage_v": 4.15,
                    },
                    {
                        "type": "step_current",
                        "mode": "discharge",
                        "current_a": discharge_2c_A,
                        "until_voltage_v": 3.10,
                    },
                ],
            }
        ],
        "period": "1s",
    },
}

voltage_step_output = api.run_sim(
    base_battery=base_battery,
    cycler=voltage_step_cycle,
    designs=[],
    initialSoC=initial_soc,
    initialTemperature_degC=initial_temperature_degC,
    ambientTemperature_degC=ambient_temperature_degC,
)

voltage_step_output.plot_dynamic_response(plot_variables)

voltage_step_cycle = { "cycle_type": "CUSTOM", "selected_unit": "A", "control_parameters": { "experiment_text": [ { "type": "step_current_profile", "steps": [ { "type": "step_current", "mode": "charge", "current_a": charge_2c_A, "until_voltage_v": 3.80, }, { "type": "step_current", "mode": "charge", "current_a": charge_1p2c_A, "until_voltage_v": 4.00, }, { "type": "step_current", "mode": "charge", "current_a": charge_0p6c_A, "until_voltage_v": 4.15, }, { "type": "step_current", "mode": "discharge", "current_a": discharge_2c_A, "until_voltage_v": 3.10, }, ], } ], "period": "1s", }, } voltage_step_output = api.run_sim( base_battery=base_battery, cycler=voltage_step_cycle, designs=[], initialSoC=initial_soc, initialTemperature_degC=initial_temperature_degC, ambientTemperature_degC=ambient_temperature_degC, ) voltage_step_output.plot_dynamic_response(plot_variables)

Step charge with SoC or voltage setpoints followed by a 2C discharge. Uses CUSTOM cycler type¶

Each step_current below includes both an SoC target and a voltage cut-off. The step ends on whichever threshold is reached first, and that same rule is also used for the final 2C discharge step.

In [9]:

dual_target_step_cycle = {
    "cycle_type": "CUSTOM",
    "selected_unit": "A",
    "control_parameters": {
        "experiment_text": [
            {
                "type": "step_current_profile",
                "steps": [
                    {
                        "type": "step_current",
                        "mode": "charge",
                        "current_a": charge_2c_A,
                        "until_soc": 0.40,
                        "until_voltage_v": 3.70,
                    },
                    {
                        "type": "step_current",
                        "mode": "charge",
                        "current_a": charge_1p2c_A,
                        "until_soc": 0.60,
                        "until_voltage_v": 4.00,
                    },
                    {
                        "type": "step_current",
                        "mode": "charge",
                        "current_a": charge_0p6c_A,
                        "until_soc": 0.80,
                        "until_voltage_v": 4.10,
                    },
                    {
                        "type": "step_current",
                        "mode": "discharge",
                        "current_a": discharge_2c_A,
                        "until_soc": 0.20,
                        "until_voltage_v": 3.10,
                    },
                ],
            }
        ],
        "period": "1s",
    },
}

dual_target_step_output = api.run_sim(
    base_battery=base_battery,
    cycler=dual_target_step_cycle,
    designs=[],
    initialSoC=initial_soc,
    initialTemperature_degC=initial_temperature_degC,
    ambientTemperature_degC=ambient_temperature_degC,
)

dual_target_step_output.plot_dynamic_response(plot_variables)

dual_target_step_cycle = { "cycle_type": "CUSTOM", "selected_unit": "A", "control_parameters": { "experiment_text": [ { "type": "step_current_profile", "steps": [ { "type": "step_current", "mode": "charge", "current_a": charge_2c_A, "until_soc": 0.40, "until_voltage_v": 3.70, }, { "type": "step_current", "mode": "charge", "current_a": charge_1p2c_A, "until_soc": 0.60, "until_voltage_v": 4.00, }, { "type": "step_current", "mode": "charge", "current_a": charge_0p6c_A, "until_soc": 0.80, "until_voltage_v": 4.10, }, { "type": "step_current", "mode": "discharge", "current_a": discharge_2c_A, "until_soc": 0.20, "until_voltage_v": 3.10, }, ], } ], "period": "1s", }, } dual_target_step_output = api.run_sim( base_battery=base_battery, cycler=dual_target_step_cycle, designs=[], initialSoC=initial_soc, initialTemperature_degC=initial_temperature_degC, ambientTemperature_degC=ambient_temperature_degC, ) dual_target_step_output.plot_dynamic_response(plot_variables)

Version b7830544