New Strategy for the Morphology-Controlled Synthesis of V₂O₅ Microcrystals with Enhanced Capacitance as Battery-type Supercapacitor Electrodes

Abstract

Porous vanadium pentoxide (V2O5) microcrystals with different morphologies were synthesized through the decomposition of butterfly-like, rhombohedral, and flower-like ammonium metavanadate (NH4VO3) microcrystals, which were synthesized by the drowning-out crystallization of hydrothermal NH4VO3 aqueous solution using ethanol as both the antisolvent and the template for the self-assembly of vanadate ions. The effects of reaction conditions on the morphologies of products were characterized by scanning electron microscopy (SEM), and the possible growth mechanism was proposed. The electrochemical properties of the produced porous V2O5 with different morphologies were studied as battery-type electrodes for supercapacitors using 1 M LiClO4/propylene carbonate (PC) as the electrolyte. Rhombohedral V2O5 exhibited the highest initial specific capacitance of 641 F·g–1 at 0.5 A·g–1 among the three obtained morphologies, as well as an excellent rate capability and cycling stability, with a retention of over 119% after 2000 cycles, making it a promising electrode material for supercapacitors. The influences of morphologies on the capacitance and cycle performance are analyzed. The results indicate that the increasing complexity of the structure leads to lower specific capacitance because of the higher degree of electrode polarization and higher resistance, while the structure stability of the microcrystals is related to the rate capability as well as the cycling performance.

Architecting a Hydrated Ca0.24V2O5 Cathode with a Facile Desolvation Interface for Superior-Performance Aqueous Zinc Ion Batteries

“…45,46 The peaks at 284, 408, and 992 cm −1 correspond to the bending vibration of VO and stretching vibration of VO, respectively. 47,48 The consistent peak vibrations at 1346.8 and 1578.6 cm −1 are ascribed to the D-band and Gband of SWCNTs, which agree well with the previous XRD results. 49 Based on the high-resolution O 1s XPS spectra shown in Figure S1b, the fitted peaks situated at 530.35, 531.53, and 532.94 eV 19 are assigned to the different forms of O 2− in O− H, H 2 O, and C−O bonds, which also indicate that the water molecules have been imported successfully.…”

“…Figure d shows the Raman spectra of the C/CaVOH sample. The peaks located at 143, 523, and 689 cm –1 are attributed to the stretching vibration of vanadyl bonds in VO 6 octahedra (V 2 O 2 ) n , V 3 –O bond, and V 2 –O, respectively, suggesting the unordered V–O–V bond in the main lattice. , The peaks at 284, 408, and 992 cm –1 correspond to the bending vibration of VO and stretching vibration of VO, respectively. , The consistent peak vibrations at 1346.8 and 1578.6 cm –1 are ascribed to the D-band and G-band of SWCNTs, which agree well with the previous XRD results …”

The Role of Cation Vacancies in Electrode Materials for Enhanced Electrochemical Energy Storage: Synthesis, Advanced Characterization, and Fundamentals

“…The electrochemical performance is largely determined by the physicochemical properties of the active electrode materials, such as morphologies, [ 23–28 ] porosity, [ 29–34 ] crystal structures, [ 35–39 ] and electrical conductivity. [ 40–45 ] Despite the advantages discussed above, the employment of TMOs for energy storage still encounters several difficulties.…”

Facile Synthesis of MgCo2O4@MMoO4 (M = Co, Ni) Nanosheet Arrays on Nickel Foam as an Advanced Electrode for Asymmetric Supercapacitors

“…Figure g revealed the CV curves of MCNO-4 at 5–80 mV s –1 , and those of MCNO-2 and MCNO-6 are shown in Figure S4e and S4g. The CV curves confirmed that the MCNO electrodes also have diffusion-controlled fast electrolyte ion transport and polarization. − The GCD results at different current densities of MCNO-4 are displayed in Figure h, and those of MCNO-2 and MCNO-6 are shown in Figure S4d and S4h. The specific capacities of the MgCo 2 O 4 @NiMoO 4 electrodes were also calculated using formula 1 in the SI, further proving that the specific capacity of the MCNO-4 electrode is the largest, and detailed calculation results for each electrode are summarized in Table S3.…”