Finite Element Simulation Insights into Electrodeposition Kinetics at the Interface of Planar Microelectrodes

The electrodeposition kinetics that occur at the planar microelectrode/electrolyte interface are considered as the key theoretical basis for ensuring large-scale uniform deposition. Herein, the dynamic process of electrodeposition at the interface of planar microelectrodes can be visualized and analyzed under the condition of multiphysics coupling through the finite element simulation. The relationships among the potential gradient distribution, electrolyte conductivity, and electrode spacing on the microelectrodes were simulated by the finite element simulation, revealing the vertical potential distribution from top to bottom during electrodeposition. The immersed surface of the microelectrode into the electrolyte tended to the equipotential surface during constant voltage deposition. The cathodic electrodeposition was optimized to achieve uniform films of nickel cobalt layered double hydroxides on Au interdigitated poly­(ethylene terephthalate) substrates as flexible microelectrodes under the guidance of the simulated dynamic process, including electrode spacing, electrolyte conductivity, and deposition time and voltage. The flexible quasi-solid microsupercapacitors assembled by the PET microelectrodes can gain a decent energy density of 0.011 μW h cm–2 at the power density of 1.25 μW cm–2 and a long-term cycling stability with 85.53% capacitance retention after 20000 charge/discharge cycles.