Hydrous Ruthenium Oxide Nanoparticles Anchored to Graphene and Carbon Nanotube Hybrid Foam for Supercapacitors

Abstract

In real life applications, supercapacitors (SCs) often can only be used as part of a hybrid system together with other high energy storage devices due to their relatively lower energy density in comparison to other types of energy storage devices such as batteries and fuel cells. Increasing the energy density of SCs will have a huge impact on the development of future energy storage devices by broadening the area of application for SCs. Here, we report a simple and scalable way of preparing a three-dimensional (3D) sub-5 nm hydrous ruthenium oxide (RuO2) anchored graphene and CNT hybrid foam (RGM) architecture for high-performance supercapacitor electrodes. This RGM architecture demonstrates a novel graphene foam conformally covered with hybrid networks of RuO2 nanoparticles and anchored CNTs. SCs based on RGM show superior gravimetric and per-area capacitive performance (specific capacitance: 502.78 F g−1, areal capacitance: 1.11 F cm−2) which leads to an exceptionally high energy density of 39.28 Wh kg−1 and power density of 128.01 kW kg−1. The electrochemical stability, excellent capacitive performance, and the ease of preparation suggest this RGM system is promising for future energy storage applications.

Synthesis of NiMoS4for High-Performance Hybrid Supercapacitors

“…Therefore, electrochemical impedance spectroscopy (EIS) was carried out to further explore charge-transfer kinetics. Figure An equivalent circuit for fitting the Nyquist plots is shown in Figure 5f, 38,39 where Rs is the internal resistance, which is also known as equivalent series resistance (ESR), Rct is the charge Normally, the total charge stored in the electrode is contributed by two different processes:…”

A facile hydrothermal reflux synthesis of Ni(OH)2/GF electrode for supercapacitor application

“…Furthermore, the distinctive dimensions of the active materials are well essential for Electrochemical capacitors performance, considering the fact that the square of the diffusion distance is proportionate to the diffusion time of electrolyte ions [9,10]. In this regard, a considerable efforts have been focused on preparation of small size, porous, thin, hollow spheres materials with exposure of sufficient active sites and small diffusion length for enhancing electrochemical performance [11,12]. Ni(OH) 2 has been identified as an interesting transition metal hydroxides materials due to its easy production, low cost and great theoretical capacitance [13,14].…”

A combined approach for high-performance Li–O2 batteries: A binder-free carbon electrode and atomic layer deposition of RuO2 as an inhibitor–promoter

“…In addition to the C 1s peak at a binding energy (BE) of ∼284.6 eV for the CNTs, the XPS data for the RuO 2 /CNT electrodes show Ru 3d 5/2 peaks at BE = ∼280.7 eV, which are typical of RuO 2 . 34,37 As shown in Fig. S2 of the supplementary material, three new peaks were observed in the Raman spectra of the RuO 2 /CNT electrodes that are associated with the Raman active modes of RuO 2 : ∼494 cm 1 for E g , ∼613 cm 1 for A 1g , and ∼685 cm 1 for B 2g .…”