Characterization of α-MoO3 anode with aqueous beryllium sulfate for supercapacitors

Icaza, Juan C.; Guduru, Ramesh K.

doi:10.1016/j.jallcom.2017.08.031

Cited by 23 publications

(6 citation statements)

References 25 publications

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“…Accordingly, the diffusion coefficients of H + for intercalation and deintercalation are calculated to be 3.305 ± 0.015 × 10 –8 and 1.800 ± 0.017 × 10 –8 cm 2 s –1 , respectively. Remarkably, the diffusion rate of H + in MoO 2+ x films is 10 4 times faster than the previously reported diffusion coefficient of H + for intercalation in an α-MoO 3 supercapacitor (∼3.32 × 10 –12 cm 2 s –1 ) . This enhanced diffusion rate is attributed to the improved electrical conductivity of the coalesced amorphous nanoparticle film.…”

Section: Resultsmentioning

confidence: 62%

“…Remarkably, the diffusion rate of H + in MoO 2+x films is 10 4 times faster than the previously reported diffusion coefficient of H + for intercalation in an α-MoO 3 supercapacitor (∼3.32 × 10 −12 cm 2 s −1 ). 39 This enhanced diffusion rate is attributed to the improved electrical conductivity of the coalesced amorphous nanoparticle film. To further understand the electrochemical behavior of this electrode, the galvanostatic charge/discharge processes were measured under different current densities.…”

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confidence: 99%

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Oxygen-Vacancy-Tunable Electrochemical Properties of Electrodeposited Molybdenum Oxide Films

Zhang

Firby

et al. 2019

ACS Appl. Mater. Interfaces

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Molybdenum oxides have been widely studied in recent years, owing to their electrochromic properties, electrocatalytic activities for hydrogen evolution reactions (HERs) and excellent energy storage performance. These characteristics strongly depend on the valence states of Mo in the oxides such as IV, V, and VI, which can be efficiently altered through oxygen deficiencies within the oxides. Here, we present a colloidal electrodeposition method to introduce oxygen vacancies in such Mo oxide films. We prepared uniform MoO x films and investigated their electrochemical characteristics under different valence states IV, V, and VI. In this paper, we demonstrate that MoO 2+x films, where Mo in valence states IV and V, can be used for high-performance supercapacitor electrodes. Due to their high conductivity, they exhibit an areal capacitance of 89 mF cm −2 at 1 mA cm −2 and negligible capacitance loss within 600 cycles. Additionally, we demonstrate that, in a complementary electrochromic device configuration, the introduction of an MoO 2+x counter electrode remarkably lowers the activation potential of WO 3 from −2 to −0.5 V and achieves a fully bleached state at 0.5 V. These properties make the MoO 2+x film an ideal counter electrode to store ions for an electrochromic device. Furthermore, MoO 3−y films, where Mo in the valence states V and VI, are obtained by annealing the electrodeposited MoO 2+x film under 200 °C for 24 h. Such films exhibit an excellent catalytic for the HER with an overpotential of 201 mV. Furthermore, we show that MoO 3 films, where Mo at its highest oxidation state (VI), can be obtained via annealing the MoO 2+x film at 300 °C for 6 h, and the resulting films exhibit battery characteristics. Our research provides a new and facile strategy to fabricate substoichiometric molybdenum oxide nanofilms and reveals the effect of different valences on the electrochemical performance of molybdenum oxide films, which opens new doorways for future research in the electrochemical applications of transition metal oxides.

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Section: Resultsmentioning

confidence: 62%

mentioning

confidence: 99%

Oxygen-Vacancy-Tunable Electrochemical Properties of Electrodeposited Molybdenum Oxide Films

Zhang

Firby

et al. 2019

ACS Appl. Mater. Interfaces

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“…RuO 2 has been widely studied as pseudocapacitive material for understanding the fundamental behavior of oxide materials as well as for practical applications [12,13]. In order to reduce the device cost, metal oxides and sulphides such as NiO, Co 3 O 4 , CuO, MnO 2 , V 2 O 5 , Fe 2 O 3 , MoO 3 , and CoS have been widely studied for charge storage applications [14][15][16][17][18][19][20][21][22][23]. In comparison to binary oxides/sulfides, ternary transition metal oxides/sulfides exhibit higher conductivity and provide a richer redox reaction resulting from the synergistic effect of binary and ternary metal ions [11].…”

Section: Introductionmentioning

confidence: 99%

MoO₃ thin layers on NiCo₂S₄ substrate for efficient electrochemical charge storage

et al. 2020

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Ternary oxides/sulfides have long been investigated as promising electrode materials for charge storage applications. However, it is important to rationally design nanostructured hybrid composites for superior charge storage performance as electrodes in devices. In this work, MoO 3 @NiCo 2 S 4 hybrid composites materials are synthesized by the hydrothermal method followed by annealing at different temperatures. The charge storage properties of these materials are tested by cyclic voltammetry, galvanostatic charge-discharge curves and electrochemical impedance spectroscopy. It is found that the structure of the hybrid composite material not only assists electron and charge transportation but also precisely control the volume expansion during redox reactions, contributing to superior electrochemical behavior. Among all the electrodes, the electrode fabricated with MoO 3 @NiCo 2 S 4 composite material annealed at 400 • C (MoO 3 @NiCo 2 S 4 -400) is the best for charge storage applications. At 400 • C, MoO 3 spreads as a thin layer of surface polymeric molybdates on NiCo 2 S 4 as seen in the XRD pattern. Significantly, it delivers the highest capacitance of 1622 F g −1 at 1 A g −1 in 2 M aqueous KOH electrolyte compared to other hybrid composite electrodes, NiCo 2 S 4 (962 F g −1 ), MoO 3 @NiCo 2 S 4 -500 (1412 F g −1 ) and MoO 3 @NiCo 2 S 4 -600 (970 F g −1 ), under the same measurement conditions. Furthermore, the MoO 3 @NiCo 2 S 4 -400 hybrid electrode shows better cyclic stability with 93% capacitance retention after 3000 charge-discharge cycles at 8 A g −1 . The synergistic effect of two components and annealing temperature plays important role in enhancing the charge storage performance. This work shows the importance of the synthesis temperature on the functional character of ternary sulfide/oxide composite materials for charge storage applications.

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“…[29][30][31][32] Therefore, MoO 3 has been considered one of the promising electrode materials for supercapacitors. [33][34][35][36][37] Furthermore, the fabrication or construction of MoO 3 with a special morphology has gained a certain achievement. For instance, Wang et al synthesized a-MoO 3 nanobelts by a hydrothermal synthesis technique and treated the sample using LiCl for lithiation.…”

Section: Introductionmentioning

confidence: 99%

Two-dimensional β-MoO₃@C nanosheets as high-performance negative materials for supercapacitors with excellent cycling stability

Liu

Wang

et al. 2020

RSC Adv.

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Characterization of α-MoO3 anode with aqueous beryllium sulfate for supercapacitors

Cited by 23 publications

References 25 publications

Oxygen-Vacancy-Tunable Electrochemical Properties of Electrodeposited Molybdenum Oxide Films

Oxygen-Vacancy-Tunable Electrochemical Properties of Electrodeposited Molybdenum Oxide Films

MoO₃ thin layers on NiCo₂S₄ substrate for efficient electrochemical charge storage

Two-dimensional β-MoO₃@C nanosheets as high-performance negative materials for supercapacitors with excellent cycling stability

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Characterization of α-MoO3 anode with aqueous beryllium sulfate for supercapacitors

Cited by 23 publications

References 25 publications

Oxygen-Vacancy-Tunable Electrochemical Properties of Electrodeposited Molybdenum Oxide Films

Oxygen-Vacancy-Tunable Electrochemical Properties of Electrodeposited Molybdenum Oxide Films

MoO3 thin layers on NiCo2S4 substrate for efficient electrochemical charge storage

Two-dimensional β-MoO3@C nanosheets as high-performance negative materials for supercapacitors with excellent cycling stability

Contact Info

Product

Resources

About

MoO₃ thin layers on NiCo₂S₄ substrate for efficient electrochemical charge storage

Two-dimensional β-MoO₃@C nanosheets as high-performance negative materials for supercapacitors with excellent cycling stability