Electrodeposition of ordered mesoporous cobalt hydroxide film from lyotropic liquid crystal media for electrochemical capacitors

Zhou, Wenjia; Zhang, Jin; Xue, Tong; Zhao, Dandan; Li, Hu‐Lin

doi:10.1039/b715070a

Cited by 135 publications

(82 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This large surface area is comparable to the surface www.afm-journal.de area of template fabricated mesoporous manganese dioxide, around 91 m 2 g À1 . [36] It is also higher than recently reported manganese dioxide nanowires ($69 m 2 g À1 ) [37] and self-assembled mesoporous-nanostructured manganese oxide ($70 m 2 g À1 ). [38] The macropores discernible on the SEM images could not account solely for such a large surface area; in fact, 76.1 m 2 g À1 of the 96.2 m 2 g À1 came from mesopores with the pore size distribution centered at a diameter of 4.2 nm.…”

Section: Introductionmentioning

confidence: 67%

Mesoporous Hydrous Manganese Dioxide Nanowall Arrays with Large Lithium Ion Energy Storage Capacities

Liu¹,

García²,

Zhang³

et al. 2009

Adv Funct Materials

162

102

View full text Add to dashboard Cite

Novel nanowall arrays of hydrous manganese dioxide MnO2 · 0.5H2O are deposited onto cathodic substrates by the potentiostatic method from a mixed aqueous solution of manganese acetate and sodium sulfate. The deposition is induced by a change of local pH resulting from electrolysis of H2O, and hierarchical mesoporous nanowall arrays are formed as a result of simultaneous precipitation of manganese hydroxide and release of hydrogen gas bubbles from the cathode. The morphology and lithium ion intercalation properties are found to change appreciably with the concentration of the precursor electrolyte, with a significant reduction in specific surface area with an increased precursor concentration. For example, mesoporous nanowall arrays deposited from 0.1 M solution possess a surface area of ∼96 m2 g−1 and exhibit a stable high intercalation capacity of 256 mA hg−1 with a film of 0.5 µm in thickness, far exceeding the theoretical limit of 150 mA hg−1 for manganese dioxide bulk film. Such mesoporous nanowall arrays offer much greater energy storage capacity (e.g., ∼230 mA hg−1 for films of ∼2.5 µm) than that of anodic deposited films of the same thickness (∼80 mA hg−1). Such high lithium ion intercalation capacity and excellent cyclic stability of the mesoporous nanowall arrays, especially for thicker films, are ascribed to the hierarchically structured macro‐ and mesoporosity of the MnO2 · 0.5H2O nanowall arrays, which offer large surface to volume ratio favoring interface Faradaic reactions, short solid‐state diffusion paths, and freedom to permit volume change during lithium ion intercalation and de‐intercalation.

show abstract

Section: Introductionmentioning

confidence: 67%

Mesoporous Hydrous Manganese Dioxide Nanowall Arrays with Large Lithium Ion Energy Storage Capacities

Liu¹,

García²,

Zhang³

et al. 2009

Adv Funct Materials

162

102

View full text Add to dashboard Cite

show abstract

“…[5,6] To improve power and energy densities, much effort has been devoted to investigating pseudocapacitive transition-metal oxides, which produce larger capacitance due to multielectron transfer during fast faradaic reactions. Transition-metal oxides can be divided into two groups: noble-metal oxides and cheap-metal oxides.…”

Section: Introductionmentioning

confidence: 99%

Graphene Sheet/Porous NiO Hybrid Film for Supercapacitor Applications

Xia

Mai

et al. 2011

Chemistry A European J

280

146

View full text Add to dashboard Cite

We report the preparation of a nickel-foam-supported graphene sheet/porous NiO hybrid film by the combination of electrophoretic deposition and chemical-bath deposition. The obtained graphene-sheet film of about 19 layers was used as the nanoscale substrate for the formation of a highly porous NiO film made up of interconnected NiO flakes with a thickness of 10-20 nm. The graphene sheet/porous NiO hybrid film exhibits excellent pseudocapacitive behavior with pseudocapacitances of 400 and 324 F g(-1) at 2 and 40 A g(-1), respectively, which is higher than those of the porous NiO film (279 and 188 F g(-1) at 2 and 40 A g(-1)). The enhancement of the pseudocapacitive properties is due to reinforcement of the electrochemical activity of the graphene-sheet film.

show abstract

“…In this way, the specific capacitance of the porous Co(OH) 2 nanoflake film electrode at a galvanostatic current density of 2, 4, 8, 10, 20 and 40 A g −1 are 935, 908, 870, 842, 756 and 589 F g −1 , respectively. With the current density increasing, partial active materials have no time to react, leading to the specific capacitance decrease [12,18]. The 63% of capacitance is retained when the current density changes from 2 to 40 A g −1 .…”

Section: Electrochemical Measurementsmentioning

confidence: 97%

Hydrothermal synthesized porous Co(OH)2 nanoflake film for supercapacitor application

et al. 2012

View full text Add to dashboard Cite

Porous Co(OH) 2 film directly grown on nickel foam is prepared by a facile hydrothermal method. The as-prepared Co(OH) 2 film possesses a structure consisting of randomly porous nanoflakes with thicknesses of 20-30 nm. The capacitive behavior of the Co(OH) 2 film is investigated by cyclic voltammograms and galvanostatic charge-discharge tests in 2 mol/L KOH. The porous Co(OH) 2 film exhibits a high discharge capacitance of 935 F g −1 at a current density of 2 A g −1 and excellent rate capability. The specific capacitance keeps a capacitance of 589 F g −1 when the current density increases to 40 A g −1 . The specific capacitance of 82.6% is maintained after 1500 cycles at 2 A g −1 . Pseudocapacitive materials, such as transition metal oxides/hydroxides and conducting polymers, are being explored for producing supercapacitors with increased specific capacitances (several times larger than those of carbonaceous materials) and high energy densities [2−6]. RuO 2 -base electrode materials are well studied as pseudocapacitive electrode materials with remarkable performance (760 F g −1 for a single electrode system) [7]. However, apart from being toxic, RuO 2 is quite expensive for extensive commercial applications. Therefore, great efforts have been devoted to searching for inexpensive alternative transition metal oxides/hydroxides materials with good capacitive characteristics [8−17]. Co(OH) 2 is an attractive pseudocapacitive material because of its high specific capacitance, well-defined electrochemical redox activity, and low cost [14,15]. A nano-level whisker-like Co(OH) 2 powder was fabricated by Yuan's group [15] and showed excellent electrochemical performance. On the other hand, it is well accepted that pseudo-capacitance is an interfacial phenomenon tightly related to the morphology of electroactive materials. The porous structure could provide a very short diffusion pathway for ions as well as large active surface area, leading to enhanced electrochemical properties [2,3,5]. Compared to powder, the film structure materials have good conductivity under the same conditions.In the present work, the porous Co(OH) 2 nanoflake film on nickel foam is prepared by hydrothermal method. Remarkably, the as-prepared film exhibits superior performances with excellent capacity retention and high specific

show abstract

Electrodeposition of ordered mesoporous cobalt hydroxide film from lyotropic liquid crystal media for electrochemical capacitors

Cited by 135 publications

References 34 publications

Mesoporous Hydrous Manganese Dioxide Nanowall Arrays with Large Lithium Ion Energy Storage Capacities

Mesoporous Hydrous Manganese Dioxide Nanowall Arrays with Large Lithium Ion Energy Storage Capacities

Graphene Sheet/Porous NiO Hybrid Film for Supercapacitor Applications

Hydrothermal synthesized porous Co(OH)2 nanoflake film for supercapacitor application

Contact Info

Product

Resources

About