Merge pull request #3096 from pybamm-team/fix-prada

fix Prada parameter set
pybamm-team · Jul 5, 2023 · 65d3944 · 65d3944
2 parents d01eb78 + 8e9b7df
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,12 +1,16 @@
 # [Unreleased](https://github.com/pybamm-team/PyBaMM/)
 
+## Bug fixes
+
+- Parameters in `Prada2013` have been updated to better match those given in the paper, which is a 2.3 Ah cell, instead of the mix-and-match with the 1.1 Ah cell from Lain2019.
+
 # [v23.5](https://github.com/pybamm-team/PyBaMM/tree/v23.5) - 2023-06-18
 
 ## Features
 
 - Enable multithreading in IDAKLU solver ([#2947](https://github.com/pybamm-team/PyBaMM/pull/2947))
 - If a solution contains cycles and steps, the cycle number and step number are now saved when `solution.save_data()` is called ([#2931](https://github.com/pybamm-team/PyBaMM/pull/2931))
-- Experiments can now be given a `start_time` to define when each step should be triggered ([#2616](https://github.com/pybamm-team/PyBaMM/pull/2616)) 
+- Experiments can now be given a `start_time` to define when each step should be triggered ([#2616](https://github.com/pybamm-team/PyBaMM/pull/2616))
 
 ## Optimizations
 
@@ -43,7 +47,6 @@
 - PyBaMM is now natively supported on Apple silicon chips (`M1/M2`) ([#2435](https://github.com/pybamm-team/PyBaMM/pull/2435))
 - PyBaMM is now supported on Python `3.10` and `3.11` ([#2435](https://github.com/pybamm-team/PyBaMM/pull/2435))
 
-
 ## Optimizations
 
 - Fixed deprecated `interp2d` method by switching to `xarray.DataArray` as the backend for `ProcessedVariable` ([#2907](https://github.com/pybamm-team/PyBaMM/pull/2907))

diff --git a/pybamm/input/parameters/lithium_ion/Prada2013.py b/pybamm/input/parameters/lithium_ion/Prada2013.py
@@ -4,7 +4,7 @@
 def graphite_LGM50_ocp_Chen2020(sto):
     """
     LG M50 Graphite open-circuit potential as a function of stochiometry, fit taken
-    from [1].
+    from [1]. Prada2013 doesn't give an OCP for graphite, so we use this instead.
 
     References
     ----------
@@ -74,9 +74,10 @@ def graphite_LGM50_electrolyte_exchange_current_density_Chen2020(
     )
 
 
-def LFP_ocp_ashfar2017(sto):
+def LFP_ocp_Afshar2017(sto):
     """
-    Open-circuit potential for LFP
+    Open-circuit potential for LFP. Prada2013 doesn't give an OCP for LFP, so we use
+    Afshar2017 instead.
 
     References
     ----------
@@ -134,47 +135,10 @@ def LFP_electrolyte_exchange_current_density_kashkooli2017(c_e, c_s_surf, c_s_ma
     )
 
 
-def electrolyte_diffusivity_Nyman2008(c_e, T):
-    """
-    Diffusivity of LiPF6 in EC:EMC (3:7) as a function of ion concentration. The data
-    comes from [1]
-
-    References
-    ----------
-    .. [1] A. Nyman, M. Behm, and G. Lindbergh, "Electrochemical characterisation and
-    modelling of the mass transport phenomena in LiPF6-EC-EMC electrolyte,"
-    Electrochim. Acta, vol. 53, no. 22, pp. 6356–6365, 2008.
-
-    Parameters
-    ----------
-    c_e: :class:`pybamm.Symbol`
-        Dimensional electrolyte concentration
-    T: :class:`pybamm.Symbol`
-        Dimensional temperature
-
-    Returns
-    -------
-    :class:`pybamm.Symbol`
-        Solid diffusivity
-    """
-
-    D_c_e = 8.794e-11 * (c_e / 1000) ** 2 - 3.972e-10 * (c_e / 1000) + 4.862e-10
-
-    # Nyman et al. (2008) does not provide temperature dependence
-
-    return D_c_e
-
-
-def electrolyte_conductivity_Nyman2008(c_e, T):
+def electrolyte_conductivity_Prada2013(c_e, T):
     """
     Conductivity of LiPF6 in EC:EMC (3:7) as a function of ion concentration. The data
-    comes from [1].
-
-    References
-    ----------
-    .. [1] A. Nyman, M. Behm, and G. Lindbergh, "Electrochemical characterisation and
-    modelling of the mass transport phenomena in LiPF6-EC-EMC electrolyte,"
-    Electrochim. Acta, vol. 53, no. 22, pp. 6356–6365, 2008.
+    comes from :footcite:`Prada2013`.
 
     Parameters
     ----------
@@ -186,126 +150,92 @@ def electrolyte_conductivity_Nyman2008(c_e, T):
     Returns
     -------
     :class:`pybamm.Symbol`
-        Solid diffusivity
+        Solid conductivity
     """
+    # convert c_e from mol/m3 to mol/L
+    c_e = c_e / 1e6
 
     sigma_e = (
-        0.1297 * (c_e / 1000) ** 3 - 2.51 * (c_e / 1000) ** 1.5 + 3.329 * (c_e / 1000)
-    )
-
-    # Nyman et al. (2008) does not provide temperature dependence
+        4.1253e-4
+        + 5.007 * c_e
+        - 4721.2 * c_e**2
+        + 1.5094e6 * c_e**3
+        - 1.6018e8 * c_e**4
+    ) * 1e3
 
     return sigma_e
 
 
 # Call dict via a function to avoid errors when editing in place
 def get_parameter_values():
     """
-    Parameters for an A123 LFP cell, from the paper :footcite:t:`Lain2019`
-
-    LG M50 Graphite negative electrode parameters
-    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-    Parameters for negative electrode (graphite) and separator are from the paper
-    :footcite:t:`Chen2020` and references therein.
-
-    Parameters for positive electrode (LFP) are from the paper :footcite:t:`Prada2013`
-    and references therein. The functions used for OCP and exchange-current density are
-    from separate references (documented within the functions), to provide better fit to
-    data
-
-    Parameters for a LiPF6 electrolyte are from the paper :footcite:t:`Nyman2008`and
-    references therein.
+    Parameters for an LFP cell, from the paper :footcite:t:`Prada2013`
     """
 
     return {
         "chemistry": "lithium_ion",
         # cell
-        "Negative current collector thickness [m]": 1e-05,
-        "Negative electrode thickness [m]": 3.6e-05,
-        "Separator thickness [m]": 1.8e-05,
-        "Positive electrode thickness [m]": 8.1e-05,
-        "Positive current collector thickness [m]": 1.9e-05,
-        "Electrode height [m]": 0.0649,
-        "Electrode width [m]": 1.78,
-        "Negative tab width [m]": 0.04,
-        "Negative tab centre y-coordinate [m]": 0.06,
-        "Negative tab centre z-coordinate [m]": 0.137,
-        "Positive tab width [m]": 0.04,
-        "Positive tab centre y-coordinate [m]": 0.147,
-        "Positive tab centre z-coordinate [m]": 0.137,
-        "Negative current collector conductivity [S.m-1]": 58411000.0,
-        "Positive current collector conductivity [S.m-1]": 36914000.0,
-        "Negative current collector density [kg.m-3]": 8960.0,
-        "Positive current collector density [kg.m-3]": 2700.0,
-        "Negative current collector specific heat capacity [J.kg-1.K-1]": 385.0,
-        "Positive current collector specific heat capacity [J.kg-1.K-1]": 897.0,
-        "Negative current collector thermal conductivity [W.m-1.K-1]": 401.0,
-        "Positive current collector thermal conductivity [W.m-1.K-1]": 237.0,
-        "Nominal cell capacity [A.h]": 1.1,
-        "Current function [A]": 1.1,
+        "Negative electrode thickness [m]": 3.4e-05,
+        "Separator thickness [m]": 2.5e-05,
+        "Positive electrode thickness [m]": 8e-05,
+        "Electrode height [m]": 0.6,  # to give an area of 0.18 m2
+        "Electrode width [m]": 0.3,  # to give an area of 0.18 m2
+        "Nominal cell capacity [A.h]": 2.3,
+        "Current function [A]": 2.3,
         "Contact resistance [Ohm]": 0,
         # negative electrode
         "Negative electrode conductivity [S.m-1]": 215.0,
-        "Maximum concentration in negative electrode [mol.m-3]": 33133.0,
-        "Negative electrode diffusivity [m2.s-1]": 3.3e-14,
+        "Maximum concentration in negative electrode [mol.m-3]": 30555,
+        "Negative electrode diffusivity [m2.s-1]": 3e-15,
         "Negative electrode OCP [V]": graphite_LGM50_ocp_Chen2020,
-        "Negative electrode porosity": 0.25,
-        "Negative electrode active material volume fraction": 0.75,
-        "Negative particle radius [m]": 5.86e-06,
+        "Negative electrode porosity": 0.36,
+        "Negative electrode active material volume fraction": 0.58,
+        "Negative particle radius [m]": 5e-6,
         "Negative electrode Bruggeman coefficient (electrolyte)": 1.5,
         "Negative electrode Bruggeman coefficient (electrode)": 1.5,
         "Negative electrode charge transfer coefficient": 0.5,
         "Negative electrode double-layer capacity [F.m-2]": 0.2,
         "Negative electrode exchange-current density [A.m-2]"
         "": graphite_LGM50_electrolyte_exchange_current_density_Chen2020,
-        "Negative electrode density [kg.m-3]": 1657.0,
-        "Negative electrode specific heat capacity [J.kg-1.K-1]": 700.0,
-        "Negative electrode thermal conductivity [W.m-1.K-1]": 1.7,
-        "Negative electrode OCP entropic change [V.K-1]": 0.0,
+        "Negative electrode OCP entropic change [V.K-1]": 0,
         # positive electrode
         "Positive electrode conductivity [S.m-1]": 0.33795074,
         "Maximum concentration in positive electrode [mol.m-3]": 22806.0,
         "Positive electrode diffusivity [m2.s-1]": 5.9e-18,
-        "Positive electrode OCP [V]": LFP_ocp_ashfar2017,
-        "Positive electrode porosity": 0.12728395,
-        "Positive electrode active material volume fraction": 0.28485556,
-        "Positive particle radius [m]": 1e-08,
+        "Positive electrode OCP [V]": LFP_ocp_Afshar2017,
+        "Positive electrode porosity": 0.426,
+        "Positive electrode active material volume fraction": 0.374,
+        "Positive particle radius [m]": 5e-08,
         "Positive electrode Bruggeman coefficient (electrode)": 1.5,
         "Positive electrode Bruggeman coefficient (electrolyte)": 1.5,
         "Positive electrode charge transfer coefficient": 0.5,
         "Positive electrode double-layer capacity [F.m-2]": 0.2,
-        "Positive electrode density [kg.m-3]": 2341.17,
-        "Positive electrode specific heat capacity [J.kg-1.K-1]": 1100.0,
-        "Positive electrode thermal conductivity [W.m-1.K-1]": 2.1,
-        "Positive electrode OCP entropic change [V.K-1]": 0.0,
         "Positive electrode exchange-current density [A.m-2]"
         "": LFP_electrolyte_exchange_current_density_kashkooli2017,
+        "Positive electrode OCP entropic change [V.K-1]": 0,
         # separator
-        "Separator porosity": 0.47,
+        "Separator porosity": 0.45,
         "Separator Bruggeman coefficient (electrolyte)": 1.5,
-        "Separator density [kg.m-3]": 397.0,
-        "Separator specific heat capacity [J.kg-1.K-1]": 700.0,
-        "Separator thermal conductivity [W.m-1.K-1]": 0.16,
         # electrolyte
-        "Initial concentration in electrolyte [mol.m-3]": 1000.0,
-        "Cation transference number": 0.2594,
+        "Initial concentration in electrolyte [mol.m-3]": 1200.0,
+        "Cation transference number": 0.36,
         "Thermodynamic factor": 1.0,
-        "Electrolyte diffusivity [m2.s-1]": electrolyte_diffusivity_Nyman2008,
-        "Electrolyte conductivity [S.m-1]": electrolyte_conductivity_Nyman2008,
+        "Electrolyte diffusivity [m2.s-1]": 2e-10,
+        "Electrolyte conductivity [S.m-1]": electrolyte_conductivity_Prada2013,
         # experiment
-        "Reference temperature [K]": 298.15,
-        "Heat transfer coefficient [W.m-2.K-1]": 10.0,
-        "Ambient temperature [K]": 298.15,
+        "Reference temperature [K]": 298,
+        "Ambient temperature [K]": 298,
         "Number of electrodes connected in parallel to make a cell": 1.0,
         "Number of cells connected in series to make a battery": 1.0,
         "Lower voltage cut-off [V]": 2.0,
-        "Upper voltage cut-off [V]": 4.4,
+        "Upper voltage cut-off [V]": 3.6,
         "Open-circuit voltage at 0% SOC [V]": 2.0,
-        "Open-circuit voltage at 100% SOC [V]": 4.4,
-        "Initial concentration in negative electrode [mol.m-3]": 28831.45783,
-        "Initial concentration in positive electrode [mol.m-3]": 35.3766672,
-        "Initial temperature [K]": 298.15,
+        "Open-circuit voltage at 100% SOC [V]": 3.6,
+        # initial concentrations adjusted to give 2.3 Ah cell with 3.6 V OCV at 100% SOC
+        # and 2.0 V OCV at 0% SOC
+        "Initial concentration in negative electrode [mol.m-3]": 0.81 * 30555,
+        "Initial concentration in positive electrode [mol.m-3]": 0.0038 * 22806,
+        "Initial temperature [K]": 298,
         # citations
-        "citations": ["Chen2020", "Lain2019", "Prada2013", "Nyman2008"],
+        "citations": ["Chen2020", "Prada2013"],
     }