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Hierarchical Core/Shell NiCo2O4@NiCo2O4 Nanocactus Arrays with Dual-functionalities for High Performance Supercapacitors and Li-ion Batteries.

Cheng J, Lu Y, Qiu K, Yan H, Xu J, Han L, Liu X, Luo J, Kim JK, Luo Y - Sci Rep (2015)

Bottom Line: We report the synthesis of three dimensional (3D) NiCo2O4@NiCo2O4 nanocactus arrays grown directly on a Ni current collector using a facile solution method followed by electrodeposition.As the SC electrode, they deliver a remarkable specific capacitance of 1264 F g(-1) at a current density of 2 A g(-1) and ~93.4% of capacitance retention after 5000 cycles at 2 A g(-1).When used as the anode for LIBs, a high reversible capacity of 925 mA h g(-1) is achieved at a rate of 120 mA g(-1) with excellent cyclic stability and rate capability.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Advanced Micro/Nano Functional Materials, School of Physics and Electronic Engineering, Xinyang Normal University, Xinyang, P. R. China.

ABSTRACT
We report the synthesis of three dimensional (3D) NiCo2O4@NiCo2O4 nanocactus arrays grown directly on a Ni current collector using a facile solution method followed by electrodeposition. They possess a unique 3D hierarchical core-shell structure with large surface area and dual-functionalities that can serve as electrodes for both supercapacitors (SCs) and lithium-ion batteries (LIBs). As the SC electrode, they deliver a remarkable specific capacitance of 1264 F g(-1) at a current density of 2 A g(-1) and ~93.4% of capacitance retention after 5000 cycles at 2 A g(-1). When used as the anode for LIBs, a high reversible capacity of 925 mA h g(-1) is achieved at a rate of 120 mA g(-1) with excellent cyclic stability and rate capability. The ameliorating features of the NiCo2O4 core/shell structure grown directly on highly conductive Ni foam, such as hierarchical mesopores, numerous hairy needles and a large surface area, are responsible for the fast electron/ion transfer and large active sites which commonly contribute to the excellent electrochemical performance of both the SC and LIB electrodes.

No MeSH data available.


Related in: MedlinePlus

SEM images of(a-c) NiCo2O4 NCAs taken at low- and high-magnifications; (d-f) NiCo2O4@NiCo2O4 NCAs taken at different magnifications.
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f3: SEM images of(a-c) NiCo2O4 NCAs taken at low- and high-magnifications; (d-f) NiCo2O4@NiCo2O4 NCAs taken at different magnifications.

Mentions: Figure 3a shows the SEM image of the as-synthesized well-ordered NiCo2O4 NCAs. It can be seen that large-scale, dense and aligned NiCo2O4 nanocactuses grow uniformly on the skeletons of Ni foam. The NCA structure was hierarchical, consisting of primary intermingled stems and secondary acicular needles emanated from the main stems, as shown by the high-magnification SEM images (Fig. 3b,c). The acicular needles were several tens of nanometer thick and more than 1 μm long. After the electrochemical deposition and annealing, a thin layer of NiCo2O4 flakes was covered on the surface of each NiCo2O4 nanocactus, forming a core/shell hierarchical structure (Fig. 3d). It can be found that the NiCo2O4 nanoflakes were porous and interconnected with each other (Fig. 3e,f), which was further confirmed by higher magnification SEM image (inset of Fig. 3f). The pores or voids inside the structure are beneficial to the electrolyte infiltration, and the interconnected nature enables fast ion and electron transportation.


Hierarchical Core/Shell NiCo2O4@NiCo2O4 Nanocactus Arrays with Dual-functionalities for High Performance Supercapacitors and Li-ion Batteries.

Cheng J, Lu Y, Qiu K, Yan H, Xu J, Han L, Liu X, Luo J, Kim JK, Luo Y - Sci Rep (2015)

SEM images of(a-c) NiCo2O4 NCAs taken at low- and high-magnifications; (d-f) NiCo2O4@NiCo2O4 NCAs taken at different magnifications.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4487229&req=5

f3: SEM images of(a-c) NiCo2O4 NCAs taken at low- and high-magnifications; (d-f) NiCo2O4@NiCo2O4 NCAs taken at different magnifications.
Mentions: Figure 3a shows the SEM image of the as-synthesized well-ordered NiCo2O4 NCAs. It can be seen that large-scale, dense and aligned NiCo2O4 nanocactuses grow uniformly on the skeletons of Ni foam. The NCA structure was hierarchical, consisting of primary intermingled stems and secondary acicular needles emanated from the main stems, as shown by the high-magnification SEM images (Fig. 3b,c). The acicular needles were several tens of nanometer thick and more than 1 μm long. After the electrochemical deposition and annealing, a thin layer of NiCo2O4 flakes was covered on the surface of each NiCo2O4 nanocactus, forming a core/shell hierarchical structure (Fig. 3d). It can be found that the NiCo2O4 nanoflakes were porous and interconnected with each other (Fig. 3e,f), which was further confirmed by higher magnification SEM image (inset of Fig. 3f). The pores or voids inside the structure are beneficial to the electrolyte infiltration, and the interconnected nature enables fast ion and electron transportation.

Bottom Line: We report the synthesis of three dimensional (3D) NiCo2O4@NiCo2O4 nanocactus arrays grown directly on a Ni current collector using a facile solution method followed by electrodeposition.As the SC electrode, they deliver a remarkable specific capacitance of 1264 F g(-1) at a current density of 2 A g(-1) and ~93.4% of capacitance retention after 5000 cycles at 2 A g(-1).When used as the anode for LIBs, a high reversible capacity of 925 mA h g(-1) is achieved at a rate of 120 mA g(-1) with excellent cyclic stability and rate capability.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Advanced Micro/Nano Functional Materials, School of Physics and Electronic Engineering, Xinyang Normal University, Xinyang, P. R. China.

ABSTRACT
We report the synthesis of three dimensional (3D) NiCo2O4@NiCo2O4 nanocactus arrays grown directly on a Ni current collector using a facile solution method followed by electrodeposition. They possess a unique 3D hierarchical core-shell structure with large surface area and dual-functionalities that can serve as electrodes for both supercapacitors (SCs) and lithium-ion batteries (LIBs). As the SC electrode, they deliver a remarkable specific capacitance of 1264 F g(-1) at a current density of 2 A g(-1) and ~93.4% of capacitance retention after 5000 cycles at 2 A g(-1). When used as the anode for LIBs, a high reversible capacity of 925 mA h g(-1) is achieved at a rate of 120 mA g(-1) with excellent cyclic stability and rate capability. The ameliorating features of the NiCo2O4 core/shell structure grown directly on highly conductive Ni foam, such as hierarchical mesopores, numerous hairy needles and a large surface area, are responsible for the fast electron/ion transfer and large active sites which commonly contribute to the excellent electrochemical performance of both the SC and LIB electrodes.

No MeSH data available.


Related in: MedlinePlus