Mathematical modelling and parameter classification enable understanding of dynamic shape-change issues adversely affecting high energy-density battery metal anodes

Abstract

Owing to the difficulty of studying materials in real-life battery context, research on metal anodes, suffers from a methodological gap between materials- and device-orientated studies. This gap can be bridged by quantitatively linking the electrical response of the device to the evolution of the material inside the cell. The capability of establishing this link, on the one hand, allows to frame the correct space- and time-scales that are relevant to device research and, on the other hand, helps pinpoint the global observables that can be associated with molecular-level information and imaging. This study contributes to the construction of a conceptual platform, that will enable to rationalize the electrical response of the device on the basis of materials-relevant quantities. To this aim: (i) we have developed a PDE-based mathematical model for the response of a single symmetric cell with metal electrodes; (ii) we have validated it with high-quality data from Zn/Zn symmetric coin-cell cycling in weakly acidic alkaline aqueous electrolyte, containing quaternary ammonium additives, and (iii) we have carried out a parameter-classification task for the experimental data, that notably extended the physico-chemical insight into the mechanism of action of anode-stabilizing additives.