Análise do transporte de massa em baterias de fluxo redox de pequena escala

Abstract

Progress in the analysis and on strategies to improve the mass transport in smallscale redox flow batteries is made. With the benefits brought by miniaturization of such devices, two scale-reduction approaches are analysed. Firstly, the same constructive characteristics of a membrane-based flow battery are maintained, solely miniaturizing its components. A new geometry for fluidic networks with corrugated wall channels is proposed and the theoretical-experimental analysis show its superiority against a diffusion-limited benchmark case. With the improvement in the mass transport, power densities of up to 1.3 W/cm², amongst the highest ever reported, are attained. The membraneless co-laminar flow battery alternative is explored. Devices employing both flat or corrugated solid electrodes and porous carbon electrodes in flow-by configuration are analyzed from the mass transport standpoint through integral transform, for which progress in the solution of the Navier-Stokes equations are also done. The influence of the diferente design parameters in the current density, reactants conversion and mixed potential avoidance is evaluated. The strategies focused on increasing the area-volume ratio has rendered marked improvements on the membaneless flow battery mass-transport-related performance