RuO₂ Thin Films Electrodeposited on Polystyrene Nanosphere Arrays: Growth Mechanism and Application to Supercapacitor Electrodes

Abstract

Two-dimensionally (2D) arrayed polystyrene (PS)/ruthenium oxide (RuO) core/shell nanospheres are successfully prepared by the electrodeposition of RuO nanoparticles on a hexagonal close-packed PS monolayer. This nanosphere structure is entirely different from the structure previously reported for other transition metal oxides electrodeposited on the PS nanosphere arrays. The different growth behavior is analyzed, and a possible deposition mechanism is proposed based on the morphological evolution and photoelectron spectroscopy measurements. As an electrode for supercapacitors, this 2D arrayed nanosphere structure exhibits superior capacitive properties such as significantly large areal capacitance, tight binding with current collectors, and retarded saturation of the capacitance, compared to a planar RuO film electrode.

Recent Progress in Ruthenium Oxide‐Based Composites for Supercapacitor Applications

“…It is ascribed to the better accessibility of the conducting RuO 2 to the electrolytes in the composite, superior charge transport through the resultant polymer matrix, besides disallowing easy loss and electrolytic dissolution of the metal oxide anchored to it. Similar works on conducting polymer based RuO 2 systems for high energy storage performance were recently reported . Lately, 3D‐arrays of RuO 2 nanoparticles encaged polyaniline hollow nanospheres ( RuO 2 /H‐PANI) assisted by polystyrene (PS) template synthesis were found to demonstrate specific capacitance value of 1570 F g −1 at 10 mV s −1 scan rate, indicating synergism from the components .…”

“…[163] Tunable Two-dimensionally (2D) arrayed polystyrene-RuO 2 core/shell nanospheres obtained by the electrodeposition of RuO 2 nanoparticles on hexagonal close-packed PS monolayer exhibited large capacitance (14.1 mF cm À 2 and 258 F g À 1 at current density of 0.5 mA cm À 2 ), effective binding with current collectors, and deteriorated saturation of the capacitance comparatively higher than planar oxide film electrodes. [164] Very recently, a facile and competent sonochemical technique for obtaining RuO 2 -based nanocomposites with various conducting polymers such as polyaniline, poly-(3,4-ethylenedioxythiophene) (PEDOT) and polypyrrole (PPy) where, hydrous RuO 2 nanoparticles (~10 wt % with respect to monomer) are homogeneously deposited on the polymer surface have been developed. Amongst these systems, PANI-RuO 2 nanocomposite displayed highest capacitance~670 F g À 1 at 1 A g À 1 current density with 89 % capacitance retention over 10,000 galvanostatic charge-discharge cycles.…”

“…Similar works on conducting polymer based RuO 2 systems for high energy storage performance were recently reported. [166][167] Lately, 3Darrays of RuO 2 nanoparticles encaged polyaniline hollow nanospheres (RuO 2 /H-PANI) assisted by polystyrene (PS) template synthesis were found to demonstrate specific capacitance value of 1570 F g À 1 at 10 mV s À 1 scan rate, indicating synergism from the components. [168] Such morphological designing led to high porosity with strong encaging of oxide nanoparticles are shown in Figure 12(a)-(d) that considerably enhanced the surface capacitance of the composite, ion transport properties as well as efficiently resolved the problem of undesired electrode material detachment from the current collector surface.…”

Electrode Materials for Supercapacitors: A Review of Recent Advances

“…Yim et al developed the nanospheres in core-shell structure through the electrodeposition method utilizing the 2D arrayed of polystyrene (PS) monolayer as the core and the RuO2 nanoparticles as the shell, in which the resultant nanospheres showed an excellent capacitive performance including a superior areal capacitance, well bonded to the current collector materials compared to that of planar RuO2-based electrode ( Figure 21) [436]. As it was mentioned in the previous sections, the efficiency of the SC device could be enhanced mainly by improving the electrode materials and modifying the electrolyte material.…”

Enhanced capacitive properties of all-metal-oxide-nanoparticle-based asymmetric supercapacitors

“…[14][15][16] To overcome this problem, various electrode nanostructures have been proposed to increase the contact between the electrode and electrolyte. [16][17][18][19] Although nanostructured electrodes have improved the capacitive characteristics to some extent, most fabrication techniques are still expensive and complicated for practical use. In contrast, a much simpler, low-cost preparation for a variety of TMO nanoparticles (NPs) has been well established, and hence the TMO NPs are promising materials for nanostructured supercapacitor electrodes.…”