Equivalent circuit model of a pyroelectrochemical cell

A pyroelectrochemical cell (PEC) is a “self-charging” power cell that uses a porous, pyroelectric material as the separator of an electrochemical double layer capacitor (EDLC). To-date, the fundamental physics of the PEC has been demonstrated through experiment and finite element simulation, however no investigation of design and/or operational parameters has occurred. This work proposes an equivalent circuit model of the PEC that supports rapid investigation of this energy harvesting and storage device. The model is validated against experimental open circuit potential measurements with good agreement. Circuit model elements for equivalent series resistance and pyroelectric current source are directly related to cell parameters including separator thickness, porosity, material properties, and electrolyte conductivity. An investigation into the effects of these variables on energy density reveals the importance of minimizing separator porosity. Minimum values of pyroelectric coefficient and electrolyte conductivity necessary to meet Internet of Things (IoT) benchmarks are also identified. The circuit model’s low-frequency RC time constant, representing charge redistribution and double layer capacitance of small pores, has a significant impact on energy storage, with optimum values governed by the thermal cycling rate. Overall, this work demonstrates an effective means of designing PEC devices for a wide range of IoT applications. • An equivalent circuit model of the pyroelectrochemical cell (PEC) is proposed. • Model predictions agree well with experimental open circuit potential results. • Circuit model elements are varied to explore effects of PEC design and operation.