A Segmented Cell Measuring Technique for Current Distribution Measurements in Batteries, Exemplified by the Operando Investigation of a Zn-Air Battery

A transimpedance amplifier circuit as well as an instrumental amplifier circuit were used to measure current densities of a zinc-air battery with an integrated segmented current collector foil. Error calculation showed that the transimpedance amplifier is superior to the used instrumental amplifier, but both methods provide valuable and consistent results. They both showed comparable results with operando insight into the current distribution of the battery. The knowledge about those distributions is essential to avoid fast degradation of battery materials and irreversible capacity loss due to heterogeneous dissolution of the anode during discharge. In this work we showed that oxygen starvation as well as gas flow rate leads to large current gradients. It was also demonstrated that heterogeneous current distributions on cathode side induces also a heterogenous dissolution behavior on the anode, resulting in irreversible capacity loss. (C) 2021 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited.

Automated summary

The study compared the use of transimpedance amplifier and instrumental amplifier circuits to measure current densities of a zinc-air battery, finding the transimpedance amplifier to be superior, but both methods provided valuable and consistent results. The results showed that understanding current distributions is crucial for preventing battery material degradation and irreversible capacity loss.