Method to Independently Measure the Electronic and Ionic Conductivity of Zinc Slurry Electrodes

Zn-MnO2 alkaline batteries are prevalent and reliable primary batteries due to their cost effectiveness, good safety characteristics, long shelf life and ability to deliver sustained power for continuous usage. This properties make alkaline batteries an ideal options to be used in remote controls, smoke detectors, wireless mice, toys and many portable electronic devices. Despite their advantages, the battery performance is constrained by the slurried Zinc anode. Because of this, researchers have prioritized the improvement of the anode, primarily aiming to enhance the capacity and stability of the active material. However, the actual behavior of the anode is limited by the ionic conductivity of Zinc slurry, which is several orders of magnitude lower than the electronic conductivity of the slurry. This causes the reacting front to begin at the anode-separator interface, leading to passivation of the anode, incomplete discharge and increased gassing. The utilization of Zinc in the slurry anode can be increased by bringing the values of ionic conductivity and electronic conductivity closer together. Unfortunately, due to the redox electrolyte mechanism that moves electrons through the anode [1], the literature does not have an established method that is able to independently measure the ionic and electronic conductivity of the slurry. Before methods can be proposed to improve ionic conductivity of slurry, a method must first be devised that is able to truly measure the ionic conductivity in isolation. In this study, a novel methodology is reported to quantify both the ionic and electronic conductivity of the slurried anode. This innovative approach aims to provide a deeper understanding of the complex interconnection between electronic and ionic conductivities of the Zinc slurry. By addressing this critical aspect, the research contributes to advancing the fundamental understanding of Zn-MnO2 alkaline batteries, potentially paving the way for significant improvements in their performance and reliability for a wide array of applications. References [1] E. Faegh, T. Omasta, M. Hull, S. Ferrin, S. Shrestha, J. Lechman, D. Bolintineanu, M. Zuraw and W.E. Mustain, “Understanding the Dynamics of Primary Zn-MnO2 Alkaline Battery Gassing with Operando Visualization and Pressure Cells”, J. Electrochem. Soc., 165 (2018) A2528-A2535