Limits...
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

(a) XPS general spectrum of as-synthesized NiCo2O4@NiCo2O4 NCAs; and (b-d) XPS survey scan of Ni 2p, Co 2p and O 1 s regions, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4487229&req=5

f5: (a) XPS general spectrum of as-synthesized NiCo2O4@NiCo2O4 NCAs; and (b-d) XPS survey scan of Ni 2p, Co 2p and O 1 s regions, respectively.

Mentions: The chemical compositions of the NiCo2O4@NiCo2O4 NCAs were further analyzed by X-ray photoelectron spectroscopy (XPS), as shown in Fig. 5. The general survey spectrum (Fig. 5a) indicated the presence of C, Ni, Co and O elements and the absence of other impurities. The Ni 2p spectrum (Fig. 5b) contained two prominent 2p3/2 and 2p1/2 spin-orbit peaks at binding energies of 853.5 and 872.6 eV, and two shakeup satellites (identified as “Sat.”). Two major peaks at binding energies of 779.7 and 795.2 eV were observed from the complex Co 2p curve (Fig. 5c), corresponding to the Co 2p3/2 and Co 2p1/2 spin-orbit peaks, respectively. The high-resolution O 1s spectrum (Fig. 5d) showed three peaks. Specifically, the peak at 530.0 eV is typical of metal-oxygen bonds26. The peak at 531.1 eV is usually associated with defects, contaminants and surface species, like hydroxyls, chemisorbed oxygen and under-coordinated lattice oxygen27. The peaks at ∼531.7 eV can be attributed to multiplicity of physi- and chemi-sorbed water on or near the surface25.


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)

(a) XPS general spectrum of as-synthesized NiCo2O4@NiCo2O4 NCAs; and (b-d) XPS survey scan of Ni 2p, Co 2p and O 1 s regions, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f5: (a) XPS general spectrum of as-synthesized NiCo2O4@NiCo2O4 NCAs; and (b-d) XPS survey scan of Ni 2p, Co 2p and O 1 s regions, respectively.
Mentions: The chemical compositions of the NiCo2O4@NiCo2O4 NCAs were further analyzed by X-ray photoelectron spectroscopy (XPS), as shown in Fig. 5. The general survey spectrum (Fig. 5a) indicated the presence of C, Ni, Co and O elements and the absence of other impurities. The Ni 2p spectrum (Fig. 5b) contained two prominent 2p3/2 and 2p1/2 spin-orbit peaks at binding energies of 853.5 and 872.6 eV, and two shakeup satellites (identified as “Sat.”). Two major peaks at binding energies of 779.7 and 795.2 eV were observed from the complex Co 2p curve (Fig. 5c), corresponding to the Co 2p3/2 and Co 2p1/2 spin-orbit peaks, respectively. The high-resolution O 1s spectrum (Fig. 5d) showed three peaks. Specifically, the peak at 530.0 eV is typical of metal-oxygen bonds26. The peak at 531.1 eV is usually associated with defects, contaminants and surface species, like hydroxyls, chemisorbed oxygen and under-coordinated lattice oxygen27. The peaks at ∼531.7 eV can be attributed to multiplicity of physi- and chemi-sorbed water on or near the surface25.

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