AIP Advances
·
2022
·Vol. 12
·期 5
·
IF 1.697
Li Miao,Ai Taotao,Kou Lingjiang,Song Jiajia,Bao Weiwei,Wang Yong,Wei Xueling,Li Wenhu,Deng Zhifeng,Zou Xiangyu,Wang Huhu
Electrode materials are the key to the electrochemical performance of supercapacitors. This study reports the electrochemical properties of V 2 O 5 supercapacitors. V 2 O 5 nanosheets with different morphologies were prepared by controlling the solvent under a facile hydrothermal method. The phase and the morphology of the samples were characterized by x-ray diffraction and scanning electron microscopy. The electrochemical properties of V 2 O 5 nanosheets with different morphologies were studied by cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy. The charge transfers resistance decreases from 3.2 Ω of V 2 O 5 particles to 2.0 Ω of V 2 O 5 nanosheets. V 2 O 5 nanosheets exhibit higher specific capacity (375 F g −1 ) than V 2 O 5 particles (318 F g −1 ) in K 2 SO 4 solution. The cycling capacity retention keeps 96.8% for 1000 cycles at 0.5 A g −1 in K 2 SO 4 solution, indicating better cycling stability.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Donghua Jia,Feng Zheng,Yaxuan Li,Yingying Niu,Yue Yang,Xiaodong Mao,Qiang Zhen,Peng Li,Yi Yu
In this work, two-dimensional V 2 O 5 nanosheet arrays/one-dimensional Co 3 O 4 nanoneedle arrays (2D VNSAs/1D CNNAs) composite is successfully prepared on nickel foam substrate. A variety of structural characterization techniques (SEM, XRD, EDS, TEM, and XPS) show that the as-prepared composite is V 2 O 5 monocrystal with a layered structure grafting by Co 3 O 4 polycrystal with a 1D needle-like structure. The VNSAs/CNNAs composite is used as supercapacitor electrode material. In a three-electrodes system, it shows high specific capacitance (C s ) values (1023 F g −1 @5 mV s −1 from CV curve and 826 F g −1 @0.5 A/g from GCD curve), a high coulombic efficiency (98.6 %@10 A/g), a good cyclic stability (92.7 % after 6000 cycles), a low charge transfer resistance (2.7 Ω), and a fast ionic diffusion rate (2.01 × 10 −8 cm 2 s −1 ). In a two-electrodes system, the assembled VNSAs/CNNAs//VNSAs/CNNAs symmetric supercapacitor has C s values of 445 F g −1 @5 mV s −1 and 363 F g −1 @0.5 A/g. Its cycle stability and rate capability could reach up to 92.3 % and 90.7 % after 6000 cycels, respectively. It also shows a high energy density (E d ) of 127.3 Wh kg −1 @400 W kg −1 and can retain 72.2 Wh kg −1 @8000 W kg −1 . The excellent electrochemical properties indicate that VNSAs/CNNAs composite can greatly increase the E d of supercapacitors.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 40
·18803-18810
·
IF 3.3
Yanmei Liang,Danqin Li,Yao He,Shixing Chao,Mingming Zhang,Xueqian Zhao,Weiqiang Zhou,Jingkun Xu,Baoyang Lu
The development of asymmetric supercapacitors (ASCs) with high power and energy density is greatly restricted by the low capacitance of the anode materials. V2O5 is a promising anode material with high theoretical capacity, but its low conductivity and high dissolution are not conducive to applications in energy storage. Herein, oxygen-vacancy PEDOT/V2O5 ultrathin nanosheets with a thickness of about 4.4 nm are fabricated by the oxidative polymerization of EDOT monomers on V2O5 nanosheets in the absence of other oxidants. The results of XPS and EPR confirm that the polymerization of PEDOT increases the oxygen vacancy concentration of V2O5. The PEDOT/V2O5 nanosheets exhibit a specific capacitance of 406 F g−1 at 2 mV s−1 and excellent cyclic stability in the mixed organic electrolyte of dimethyl carbonate and ethylene carbonate. The energy density of ASCs composed of PEDOT/V2O5 as the anode and activated carbon as the cathode reaches 65 W h kg−1 at a power density of 1490 W kg−1. This means that PEDOT/V2O5 has enormous potential in high-energy storage.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 17
·10543-10551
·
IF 10.733
Jin Song,Xiaojun Gu,Yaduo Cao,Hao Zhang
From the perspective of controlling visible-light-driven catalytic activities of supported metal catalysts by tailoring the band structures of semiconducting supports, we calcined pristine V2O5 in a H2 atmosphere at 250–350 °C to synthesize a series of porous two-dimensional V2O5 nanosheets with narrow bandgaps and rich oxygen vacancies, which supported Co and Ni nanoparticles as catalysts for visible-light-driven on-demand H2 evolution from ammonia borane (NH3BH3) in aqueous solution at 25 °C. The systematic investigations showed that all the catalysts had higher activities under visible light irradiation than in the dark and one Co catalyst exhibited the highest photocatalytic activity with a total turnover frequency (TOF) value of 120.4 min−1, which exceeded the values of all the reported noble metal-free catalysts. Structural characterization indicated that pristine V2O5 and the three post-modified V2O5 species had different bandgaps, valence band positions and concentrations of oxygen vacancies as well as different photocurrent densities, leading to different electron densities of active metal NPs in the supported catalysts with different catalytic activities. This was verified using the UV-vis spectra, valence band X-ray photoelectron spectroscopy, X-ray diffraction patterns and electrochemical characterization of various V2O5 species and the corresponding photocatalytic performance of catalysts.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED MATERIALS
·
2024
·Vol. 36
·期 18
·2312982
·
IF 27.4
Yang Liu,Chengjie Lu,Yunting Yang,Wenshu Chen,Fei Ye,Hongliang Dong,Yuping Wu,Renzhi Ma,Linfeng Hu
Nanoconfinement of cations in layered oxide cathode is an important approach to realize advanced zinc ion storage performance. However, thus far, the conventional hydrothermal/solvothermal route for this nanoconfinement has been restricted to its uncontrollable phase structure and the difficulty on the multiple cation co-confinement simultaneously. Herein, this work reports a general, supramolecular self-assembly of ultrathin V 2 O 5 nanosheets using various unitary cations including Na + , K + , Mg 2+ , Ca 2+ , Zn 2+ , Al 3+ , NH 4 + , and multiple cations (NH 4 + + Na + , NH 4 + + Na + + Ca 2+ , NH 4 + + Na + + Ca 2+ +Mg 2+ ). The unitary cation confinement results in a remarkable increase in the specific capacity and Zn-ion diffusion kinetics, and the multiple cation confinement gives rise to superior structural and cycling stability by multiple cation synergetic pillaring effect. The optimized diffusion coefficient of Zn-ion (7.5 × 10 −8 cm 2 s −1 ) in this assembly series surpasses most of the V-based cathodes reported up to date. The work develops a novel multiple-cations nanoconfinement strategy toward high-performance cathode for aqueous battery. It also provides new insights into the guest cation regulation of zinc-ion diffusion kinetics through a general, supramolecular assembly pathway.
研究领域:
材料科学
·
电化学
·
储能技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）