Nano-architectured Co(OH)2 electrodes constructed using an easily-manipulated electrochemical protocol for high-performance energy storage applications

Chang, Jeng‐Kuei; Wu, Chih Ming; Sun, I‐Wen

doi:10.1039/b925176f

Cited by 233 publications

(133 citation statements)

References 36 publications

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“…No impurity peaks were detected, indicating the high purity of the synthesized inorganic products. The mean particle size of the synthesized nanoparticles in the composite films was about 9.6, 10.3, 11.5, 10.8 nm for RC-001, RC-01, RC-02 and RC-05 respectively by using the Debye-Scherrer formula according to the diffraction peak at 18.8° ( Chang et al 2010 concentration, suggesting that cellulose matrix could serve as a scaffold to prevent the Co(OH) 2 nanoparticles from growing into too large. clearly seen, and the mean diameter is 8.7 ±1.8, 9.5 ± 2.0, 9.2 ± 2.0 and 10.0 ± 2.0 nm for RC-001, RC-01, RC-02 and RC-05, respectively, which agreed well with the results from XRD.…”

Section: Resultsmentioning

confidence: 99%

Cellulose scaffolds modulated synthesis of Co3O4 nanocrystals: preparation, characterization and properties

Liu

Zhou

et al. 2011

Cellulose

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Magnetic Co 3 O 4 nanoparticles were prepared by using microporous regenerated cellulose films as sacrificial scaffolds. The cellulose macromolecules and the porous structure of the films made them used as spatially confined reacting sites where Co(OH) 2 nanoparticles could be synthesized in situ. When the cellulose matrix was removed by sintering at 500°C, Co 3 O 4 nanoparticles were obtained. XRD and XPS indicated that the prepared nanoparticles were pure Co 3 O 4 without any impurity. TEM and SEM images revealed that the particle size of the nanoparticles was smaller than 100 nm. The nanoparticles had weak ferromagnetic properties at 25°C. Furthermore, the pronounced quantum confinement effects of the synthesized nanoparticles have been observed, the optical bandgap energies determined were about 1.92 * 2.12 and 2.74 * 2.76 eV for O 2-? Co 3? and O 2-? Co 2? charge-transfer processes, respectively. Furthermore, the resulted Co 3 O 4 nanoparticles behaved stable electrochemical performance with promising applications in the electrode for lithium ion battery.

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Section: Resultsmentioning

confidence: 99%

Cellulose scaffolds modulated synthesis of Co3O4 nanocrystals: preparation, characterization and properties

Liu

Zhou

et al. 2011

Cellulose

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“…3a, two main Co2p peaks were located at a binding energy of 796 (Co2p 1/2 ) and 780 eV (Co2p 3/2 ) with satellite peaks due to Plasmon losses and final state effects, respectively. The distance between these two peaks (DE b = 16 eV) indicated that Co existed as a Co(OH) 2 version [14]. Figure 3b shows the XPS spectra and curve fitting results of O1s.…”

Section: Resultsmentioning

confidence: 99%

“…This porous structure is highly desirable for enhanced electrochemical reaction kinetics in supercapacitors due to the large surface area, easy access to the electrolyte, and reduced mass and charge diffusion distances [11]. Although the electrodeposition of Co(OH) 2 has been extensively studied under different conditions through a variation of synthesis parameters such as applied current density and potential as well as bath concentration, pH, and temperature [12][13][14], the use of pulse current (PC) for the deposition of Co(OH) 2 has not been reported in the literature. The additional operating parameters of PC such as current-on time (T on ), current-off time (T off ), duty cycle (h), and frequency (f) offer a facile, direct, and effective way to further precisely control the morphology of the electrodeposited film.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical preparation and energy storage properties of nanoporous Co(OH)2 via pulse current deposition

2015

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Nanoporous Co(OH) 2 films are electrochemically deposited on Ni foams by pulse current deposition for supercapacitor application. The pore size and density are controlled by reaction conditions including frequency modulation and reaction time. The morphology of the films is monitored by SEM, and the chemical composition and crystal structure are confirmed by XPS and XRD, respectively. The electrochemical performance of the Co(OH) 2 film is characterized by cyclic voltammetry and chargedischarge tests. The charge-transfer resistances of the electrodes are examined by electrochemical impedance spectroscopy. The Co(OH) 2 film exhibits an excellent specific capacity of 1681 F g -1 at a current density of 2 A g -1 in a potential range of -0.1 to 0.4 V from the charge/discharge test; this specific capacity is much higher than that obtained by direct current deposition (623 F g -1 at the same condition) due to the highly porous structure.

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“…RuO 2 and Ni(OH) 2 ), 12 cobalt hydroxide is considered a promising candidate owing to its low cost, well-dened electrochemical reactions, layered structure with large interlayer spacing that facilitate the diffusion of electrolyte ions to the surface of electroactive material, and environmental compatibility. [13][14][15] In view of the fact that Co(OH) 2 , as a pseudocapacitive material, has limitations such as low conductivity and intense agglomeration during charge and discharge processes, its application as a high-performance supercapacitor material has not yet been realized. 16,17 In this regard, many researchers have attempted to overcome these limitations and boost the supercapacitor properties of Co(OH) 2 by using new methods and strategies for synthesis and modication of individual structures [18][19][20][21] or hybrid structures of Co(OH) 2 .…”

Section: 11mentioning

confidence: 99%

One-step cathodic electrodeposition of a cobalt hydroxide–graphene nanocomposite and its use as a high performance supercapacitor electrode material

2018

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In this study, Co(OH) 2 -reduced graphene oxide has been synthesized using a simple and rapid one-step cathodic electrodeposition method in a two electrode system at a constant current density on a stainless steel plate, and then characterized as a supercapacitive material on Ni foam. The composites were characterized by FT-IR, X-ray diffraction, scanning electron microscopy, and cyclic voltammetry using a galvanostatic charge/discharge test.The feeding ratios of the initial components for electrodeposition had a significant effect on the structure and electrochemical performance of the Co(OH) 2 -reduced graphene oxide composite. The results show that the 1 : 4 (w/w) ratio of GO : CoCl 2 $6H 2 O was optimum and produced an intertwined composite structure with impressive supercapacitive behavior. The specific capacitance of the composite was measured to be 734 F g À1 at a current density of 1 A g À1. Its rate capability was $78% at 20 A g À1 and its capacitance retention was 95% after 1000 cycles of charge-discharge. Moreover, its average energy density and power density were calculated to be 60.6 W h kg À1 and 3208 W kg À1, respectively. This green synthesis method enables a rapid and low-cost route for the large scale production of Co(OH) 2 -reduced graphene oxide nanocomposite as an efficient supercapacitor material.

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Nano-architectured Co(OH)2 electrodes constructed using an easily-manipulated electrochemical protocol for high-performance energy storage applications

Cited by 233 publications

References 36 publications

Cellulose scaffolds modulated synthesis of Co3O4 nanocrystals: preparation, characterization and properties

Cellulose scaffolds modulated synthesis of Co3O4 nanocrystals: preparation, characterization and properties

Electrochemical preparation and energy storage properties of nanoporous Co(OH)2 via pulse current deposition

One-step cathodic electrodeposition of a cobalt hydroxide–graphene nanocomposite and its use as a high performance supercapacitor electrode material

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