Redox Flow Cell

Class for cell setup and declaring electrolyte parameters.

class src.rfbzero.redox_flow_cell.ZeroDModel(volume_cls: float, volume_ncls: float, c_ox_cls: float, c_red_cls: float, c_ox_ncls: float, c_red_ncls: float, ocv_50_soc: float, resistance: float, k_0_cls: float, k_0_ncls: float, alpha_cls: float = 0.5, alpha_ncls: float = 0.5, geometric_area: float = 5.0, cls_negolyte: bool = True, time_step: float = 0.01, k_mt: float = 0.8, roughness_factor: float = 26.0, num_electrons_cls: int = 1, num_electrons_ncls: int = 1, temperature: float = 298.0)[source]

Zero dimensional model for redox flow battery (RFB) cycling [1].

Parameters:

  • volume_cls (float) – Volume of capacity-limiting side (CLS) reservoir (L).

  • volume_ncls (float) – Volume of non-capacity-limiting side (NCLS) reservoir (L).

  • c_ox_cls (float) – CLS initial concentration of oxidized species (M).

  • c_red_cls (float) – CLS initial concentration of reduced species (M).

  • c_ox_ncls (float) – NCLS initial concentration of oxidized species (M).

  • c_red_ncls (float) – NCLS initial concentration of reduced species (M).

  • ocv_50_soc (float) – Cell voltage (formal potentials E_+ - E_-) (V). If voltage > 0 then it’s a Full cell. If voltage = 0 then it’s a Symmetric cell.

  • resistance (float) – Cell ohmic resistance (ohms).

  • k_0_cls (float) – Electrochemical rate constant, CLS redox couple (cm/s).

  • k_0_ncls (float) – Electrochemical rate constant, NCLS redox couple (cm/s).

  • alpha_cls (float) – Charge transfer coefficient of CLS redox couple, dimensionless. Default is 0.5, which is standard in electrochemistry.

  • alpha_ncls (float) – Charge transfer coefficient of NCLS redox couple, dimensionless. Default is 0.5, which is standard in electrochemistry.

  • geometric_area (float) – Geometric area of cell (cm^2). Default is 5.0, a typical lab-scale cell size.

  • cls_negolyte (bool) – True if negolyte is the CLS, False if posolyte is the CLS. Default is True.

  • time_step (float) – Simulation time step (s). Default is 0.01, providing adequate balance of accuracy vs compute time.

  • k_mt (float) – Mass transport coefficient (cm/s). Default is 0.8, as used in [1].

  • roughness_factor (float) – Roughness factor, dimensionless. Total surface area divided by geometric surface area. Default is 26.0, as used in [1].

  • num_electrons_cls (int) – Number of electrons transferred per active species molecule in the CLS. Default is 1.

  • num_electrons_ncls (int) – Number of electrons transferred per active species molecule in the NCLS. Default is 1.

  • temperature (float) – Temperature of battery and electrolytes (K). Default is 298 K (25C).

Notes

Most equations are adapted from [1]. If ZeroDModel has been significant to your research please cite the paper.

[1] Modak, S.; Kwabi, D. G. A Zero-Dimensional Model for Electrochemical Behavior and Capacity Retention in Organic Flow Cells, Journal of The Electrochemical Society, 168, 2021, 080528. DOI 10.1149/1945-7111/ac1c1f