Fig. 4: Kinetics-controlled Cd plating behavior.

SEM images of Cd deposits at a current density of 10 mA cm⁻² with increasing areal capacities: from 0.1 to 5 mAh cm⁻² in 1C electrolyte (a), from 0.1 to 5 mAh cm⁻² in 1C6N electrolyte (b), and from 10 to 100 mAh cm⁻² in 1C6N electrolyte (c). Cd electrodeposition was carried out at an average temperature of 25 ± 2 °C. FIB-SEM images of cross-section Cd deposits in 1C electrolyte (d) and 1C6N electrolyte (e) with an areal capacity of 5 mAh cm⁻². f, g HAADF-STEM images of cross-sectional Cd deposits in 1C electrolyte at a current density of 10 mA cm⁻² with an areal capacity of 5 mAh cm⁻², corresponding FFT patterns shown in insets. h HAADF-STEM image of cross-sectional Cd deposit in 1C6N electrolyte at a current density of 10 mA cm⁻² with an areal capacity of 5 mAh cm⁻², corresponding FFT pattern shown in inset. Schematic of kinetics-controlled Cd plating behaviors in 1C electrolyte (i) and 1C6N electrolyte (j). Insets: optical morphologies of Cd deposits at a current density of 10 mA cm⁻² and an areal capacity of 100 mAh cm⁻² in 1C electrolyte (i) and 1C6N electrolyte (j).