Characterization of Transition-Metal Oxide Deposition on Carbon Electrodes of a Supercapacitor

Abstract

Abstract:In order to fabricate the composite electrodes of a supercapacitor, transition-metal oxide materials NiO and WO 3 were deposited on carbon electrodes by electron beam evaporation. The influences of various transition-metal oxides, scan rates of cyclic voltammograms (CVs), and galvanostatic charge/discharge tests on the characteristics of supercapacitor were studied. The charge/discharge efficiency and the lifetime of the composite electrodes were also investigated. It was found that the composite electrodes exhibited more favorable capacitance properties than those of the carbon electrodes at high scan rates. The results revealed the promotion of the capacitance property of the supercapacitor with composite electrode and the improving of the decay property in capacitance at high scan rate. In addition, the charge/discharge efficiency is close to 100% after 5000 cycles, and the composite electrode retains strong adhesion between the electrode material and the substrate.

Electrochromic Properties of Li- Doped NiO Films Prepared by RF Magnetron Sputtering

“…The LiNiO films deposited by different targets were named as Films A, B, C and D. Figure 5 shows the XRD patterns of Films A, B, C and D deposited on the glass substrates. The results show that all the films are amorphous, which might be due to the insufficient energy to induce crystalline growth of electrochromic films deposited at R.T. [14]. The amorphous state is desired because it is easier for the ion transportation in the ECDs.…”

Electrochromic Properties of Lithium-Doped Tungsten Oxide Prepared by Electron Beam Evaporation

“…The results show that all the peaks of crystalline phases that appeared belong to the ITO substrates, it means that WO 3 and Li 2 O-doped WO 3 films deposited on the ITO substrates all are amorphous. The reason may due that the films were deposited at room temperature, and the energy was insufficient to induce crystalline growth [12]. Figure 3 shows the surface morphologies of electrochromic films deposited on the ITO substrates.…”

Tunable Synthesis of Hollow Co3O4 Nanoboxes and Their Application in Supercapacitors

“…Because of unparalleled advantages such as superior power density, strong temperature adaptation, a fast charge/discharge rate and an ultralong service life, supercapacitors have significantly covered the shortage of conventional physical capacitors and batteries, and sparked considerable interest in the last decade [3][4][5]. Supercapacitors are generally classified into electric double layer capacitors storing energy depending on reversible ions absorption at the interface [6][7][8][9] and pseudocapacitors through reversible faradaic redox reactions [10][11][12][13]. The different energy storage mechanisms directly determine whether electric double layer capacitors utilize carbonaceous materials as electrode materials [6,7,14], while pseudocapacitors employ transition metal oxides/hydroxides [10,11,15].…”

“…Supercapacitors are generally classified into electric double layer capacitors storing energy depending on reversible ions absorption at the interface [6][7][8][9] and pseudocapacitors through reversible faradaic redox reactions [10][11][12][13]. The different energy storage mechanisms directly determine whether electric double layer capacitors utilize carbonaceous materials as electrode materials [6,7,14], while pseudocapacitors employ transition metal oxides/hydroxides [10,11,15]. Drawing a benefit from faradaic redox reactions, pseudocapacitors usually generate several times higher specific capacitance than that of electric double layer capacitors, and have attracted major attention in recent years [15,16].…”