Optimization of charge curve for the extreme inhibition of growing microstructures during electrodeposition

Abstract

Abstract: The formation of branched microstructures during the electrodeposition is a catastrophic event, which hampers the safe utilization of the metallic electrodes in rechargeable batteries. Focusing on the nonlinear growth dynamics of the dendritic microstructures, we tune the rate of the feeding charge against their growth pace to minimize the amount of the dendritic branching, while maintaining a constant feeding charge. The ultimate morphology of the electrodeposits has been shown to be more compact than the conventional uniform charging in terms of the density of the electrodeposits. Due to analytical derivation and the coupled development of the optimal charge form with respect to the natural kinetics of dendritic evolution in real time, we infer that it prevents the branching of the electrodeposits to the greatest extent, during the stochastic evolution of the dendrites. Impact statement: Taking into account the runaway behavior in the natural growth rate of the dendritic electrodeposition, which is slowest in the initiation (i.e., triggering) stage and is fastest in the final (i.e., short circuit) stage, we tune the rate of the feeding charge in time, inversely for highest compression of the microstructures, while maintaining a constant total charge. The controlled dendritic growth with the constant speed has analytically been proven to lead to the shortest growth compared with any other runaway growth form, while maintaining the same amount of the total charge. Subsequently, the constant rate of growth has been used as the handle to obtain the charge feeding form leading to such rate of growth. Performing stochastic molecular dynamics (MD) simulations, the ultimate morphology of the electrodeposits has been shown to be more compact than the conventional uniform charging in terms of the density of the electrodeposits. In fact, the charge feeding occurs when the density of the growing structure is the highest, and vice versa, the feeding rate is the least, when the structure is the most branched and sparse. The obtained charging protocol has been successfully tested in our experimental observations, which has visually led to the shorter accumulation of the dendrites with higher packing density. Due to analytical derivation and comparative development of the optimal pulse form with respect to the natural kinetics of dendritic evolution, we infer that it prevents the branching of the electrodeposits almost to the greatest extent, during the stochastic evolution of the dendrites. GraphicAbstract: [Figure not available: see fulltext.] © 2022, The Author(s), under exclusive License to the Materials Research Society.