A distributed constant equivalent circuit model and a method for estimating parameters for paper-based lactate biofuel cells.

• A distributed constant type equivalent circuit model for paper-based lactate biofuel cells was proposed. • Parameter values using electrochemical impedance spectroscopy (EIS) were estimated. • Local EIS measurement was performed to demonstrate the validity of the equivalent circuit model. In this study, a distributed constant-type equivalent circuit model for paper-based lactate biofuel cells (PBFCs) where the anode and cathode are formed on the same plane was constructed, and a method of determining parameter values in the equivalent circuit model was proposed. When PBFC were prepared and the electrochemical impedance of the entire cell was measured, the Nyquist diagram produced a spectrum due to the current line distribution. Parameters, such as charge transfer and solution resistances, were calculated from the obtained spectrum using theoretical impedance equations derived from the proposed equivalent circuit model proposed. In addition, the behavior of the current distribution in the battery was evaluated in detail by moving the reference electrode on and performing local electrochemical impedance spectroscopy at multiple points on the electrode. The models and methods proposed in this study are good for evaluating systems affected by distributed current lines, such as flat batteries, and for determining cell design, electrode areas, and arrangements. [Display omitted] [ABSTRACT FROM AUTHOR]