Prediction of the electrodeposition process behavior with the gravity or acceleration value at continuous and discrete scale

The vertical cylinder electrode configuration, rotating or not, is one of the most used electrochemical configurations for electrochemical processes study. Homogeneous accelerations, like gravity or inertial one, leads to a buoyant force and then to natural free flow, induced by density gradient which occurs, for example, during electrodeposition process. There is good accord between experimental and numerical results when the configuration is horizontal or when there is an intense forced convective flow. But there is rather interesting modifications when the homogeneous acceleration value is modified or when the studied electrochemical process is under natural diffusion condition. Very strong forced flows, with rotating disk or cylinder, are usually used to avoid the impact of this phenomenon. But, the convective transport is not so easy to impose: for example, during scale up of the laboratory scale process; or because of the non continuous growth of electrodeposits which leads to dendrite or columnar materials at micrometer or nanometer scales, which increase the importance in the void space of the natural diffusion transport. There is few knowledge of the impact of the acceleration forces upon the deposit properties at continuous and mesoscopic scales.In the present work, predictive calculation results of the deposition rate and the deposit structure with uniform buoyant force are presented. Numerical simulations for 0, 1 and 10 times the normal earth acceleration have been performed and are explored in details. Continuous scale calculations have been done using the finite volume method. The mesoscopic properties in term of structure are obtained using random walker calculations. The link between the inputs of this algorithm with the outputs of the continuous scale calculations is discussed. Finally, qualitative and quantitative evolution of the structure with acceleration is proposed.