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Copper nanofiber-networked cobalt oxide composites for high performance Li-ion batteries.

Nam SH, Kim YS, Shim HS, Kim JG, Bae Kim W - Nanoscale Res Lett (2011)

Bottom Line: We prepared a composite electrode structure consisting of copper nanofiber-networked cobalt oxide (CuNFs@CoOx).The copper nanofibers (CuNFs) were fabricated on a substrate with formation of a network structure, which may have potential for improving electron percolation and retarding film deformation during the discharging/charging process over the electroactive cobalt oxide.Such enhanced Li-ion storage performance may be associated with modified electrode structure at the nanoscale, improved charge transfer, and facile stress relaxation from the embedded CuNF network.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), 261 Chemdan-gwagiro, Buk-gu, Gwangju 500-712, South Korea. wbkim@gist.ac.kr.

ABSTRACT
We prepared a composite electrode structure consisting of copper nanofiber-networked cobalt oxide (CuNFs@CoOx). The copper nanofibers (CuNFs) were fabricated on a substrate with formation of a network structure, which may have potential for improving electron percolation and retarding film deformation during the discharging/charging process over the electroactive cobalt oxide. Compared to bare CoOxthin-film (CoOxTF) electrodes, the CuNFs@CoOxelectrodes exhibited a significant enhancement of rate performance by at least six-fold at an input current density of 3C-rate. Such enhanced Li-ion storage performance may be associated with modified electrode structure at the nanoscale, improved charge transfer, and facile stress relaxation from the embedded CuNF network. Consequently, the CuNFs@CoOxcomposite structure demonstrated here can be used as a promising high-performance electrode for Li-ion batteries.

No MeSH data available.


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FESEM images. (a) Horizontally layered CuNFs (the inset shows a highly magnified image of the prepared nanofiber); (b) CoOxTF prepared by RF-sputtering (the inset shows the deposited thin-film thickness); (c) the composite structure of CuNFs@CoOx(the inset shows the cross-sectional view of the nanofiber and thin-film, respectively).
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Figure 1: FESEM images. (a) Horizontally layered CuNFs (the inset shows a highly magnified image of the prepared nanofiber); (b) CoOxTF prepared by RF-sputtering (the inset shows the deposited thin-film thickness); (c) the composite structure of CuNFs@CoOx(the inset shows the cross-sectional view of the nanofiber and thin-film, respectively).

Mentions: Figure 1a shows that the prepared CuNFs were deposited on the Si substrate and they have an average diameter of ca. 50 ± 20 nm. The surface morphology of the individual CuNF can be observed in the inset figure of Figure 1a. Figure 1b shows the bare CoOxfilm structure. On the other hand, Figure 1c represents a combined morphology of both nanostructures of the one-dimensional CuNFs and the CoOx. The CuNFs@CoOxhas a rough surface compared to the bare CoOxTF, which may be ascribed to the presence of the CuNF network on the substrate. The sputtered CoOxwas deposited not only on the substrate but also on the surface of CuNFs. After CoOxdeposition, all the CuNFs seem to be covered by the CoOxlayer.


Copper nanofiber-networked cobalt oxide composites for high performance Li-ion batteries.

Nam SH, Kim YS, Shim HS, Kim JG, Bae Kim W - Nanoscale Res Lett (2011)

FESEM images. (a) Horizontally layered CuNFs (the inset shows a highly magnified image of the prepared nanofiber); (b) CoOxTF prepared by RF-sputtering (the inset shows the deposited thin-film thickness); (c) the composite structure of CuNFs@CoOx(the inset shows the cross-sectional view of the nanofiber and thin-film, respectively).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211358&req=5

Figure 1: FESEM images. (a) Horizontally layered CuNFs (the inset shows a highly magnified image of the prepared nanofiber); (b) CoOxTF prepared by RF-sputtering (the inset shows the deposited thin-film thickness); (c) the composite structure of CuNFs@CoOx(the inset shows the cross-sectional view of the nanofiber and thin-film, respectively).
Mentions: Figure 1a shows that the prepared CuNFs were deposited on the Si substrate and they have an average diameter of ca. 50 ± 20 nm. The surface morphology of the individual CuNF can be observed in the inset figure of Figure 1a. Figure 1b shows the bare CoOxfilm structure. On the other hand, Figure 1c represents a combined morphology of both nanostructures of the one-dimensional CuNFs and the CoOx. The CuNFs@CoOxhas a rough surface compared to the bare CoOxTF, which may be ascribed to the presence of the CuNF network on the substrate. The sputtered CoOxwas deposited not only on the substrate but also on the surface of CuNFs. After CoOxdeposition, all the CuNFs seem to be covered by the CoOxlayer.

Bottom Line: We prepared a composite electrode structure consisting of copper nanofiber-networked cobalt oxide (CuNFs@CoOx).The copper nanofibers (CuNFs) were fabricated on a substrate with formation of a network structure, which may have potential for improving electron percolation and retarding film deformation during the discharging/charging process over the electroactive cobalt oxide.Such enhanced Li-ion storage performance may be associated with modified electrode structure at the nanoscale, improved charge transfer, and facile stress relaxation from the embedded CuNF network.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), 261 Chemdan-gwagiro, Buk-gu, Gwangju 500-712, South Korea. wbkim@gist.ac.kr.

ABSTRACT
We prepared a composite electrode structure consisting of copper nanofiber-networked cobalt oxide (CuNFs@CoOx). The copper nanofibers (CuNFs) were fabricated on a substrate with formation of a network structure, which may have potential for improving electron percolation and retarding film deformation during the discharging/charging process over the electroactive cobalt oxide. Compared to bare CoOxthin-film (CoOxTF) electrodes, the CuNFs@CoOxelectrodes exhibited a significant enhancement of rate performance by at least six-fold at an input current density of 3C-rate. Such enhanced Li-ion storage performance may be associated with modified electrode structure at the nanoscale, improved charge transfer, and facile stress relaxation from the embedded CuNF network. Consequently, the CuNFs@CoOxcomposite structure demonstrated here can be used as a promising high-performance electrode for Li-ion batteries.

No MeSH data available.


Related in: MedlinePlus