The Role of Pulse Duty Cycle and Frequency on Dendritic Compression

Abstract

The formation of dendritic microstructures during the charging period of the battery is a critical phenomenon, hampering the sustainable utilization of energy-dense materials, such as alkaline metals as the electrode. We establish a new experimental setup and measure for tracking the dendritic tendency in real time to quantify the dendritic compression versus the conventional parameters of pulse duty cycle and frequency. In this regard, we close the scale gap between experiments (∼mm, ∼s) and affordable simulations (∼nm, ∼ms) by means of coarse-grained modeling. Analyzing the nonlinear variation of the investigated parameters versus the pulse and rest periods, we explain the limits where they remain effective, based on the formation/relaxation of the respective layers. The obtained results can be useful for designing the dendrite-resilient pulse parameters via the simultaneous utilization of experiments and simulations.

New Insights into the Modulation of Island Density of Electrodeposits Using Pulsatile Waveforms

“…Thus, for the same time span, pulse potential functions are expected to consume lesser power relative to DC. Consequently, it is worthwhile to investigate the efficacy of pulses, not only in terms of energy budget but also for other related phenomena in a number of electrochemical applications . Any pulse potential function may be universally characterized in terms of duty cycle, D , defined as D = t ON /( t ON + t OFF ), and frequency, f = 1/( t ON + t OFF ), respectively.…”

“…50−52 Electroplating with pulsed voltage has also been extensively studied for the same purpose. A plethora of literature illustrates the effects of the ON−OFF state's distribution (t ON /t OFF or t ON /(t ON + t OFF ), where t ON and t OFF are the durations of nonzero and zero voltage application, respectively) on the characteristic features of the electrodeposits, such as growth pattern (i.e., dendritic or mossy growth), 53,54 grain size, 55,56 and surface morphology. 57,58 However, very few 59 address the effect of pulse time distribution on nucleation dynamics.…”

“…A broad spectrum of literature is available on enhancement of nuclei density using organic additives, changing the background electrolytes, and employing other similar methods. − Electroplating with pulsed voltage has also been extensively studied for the same purpose. A plethora of literature illustrates the effects of the ON–OFF state’s distribution ( t ON / t OFF or t ON /( t ON + t OFF ), where t ON and t OFF are the durations of nonzero and zero voltage application, respectively) on the characteristic features of the electrodeposits, such as growth pattern (i.e., dendritic or mossy growth), , grain size, , and surface morphology. , However, very few address the effect of pulse time distribution on nucleation dynamics. Precisely, the parametric effect of standard pulse quantifiers (e.g., duty cycle, D = t ON /( t ON + t OFF ) or frequency, f = 1/( t ON + t OFF )) and the respective comparison with equivalent DC electrodeposition on the population density of islands are yet to be systematically explored.…”