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Low-temperature synthesis of CuO-interlaced nanodiscs for lithium ion battery electrodes.

Seo SD, Jin YH, Lee SH, Shim HW, Kim DW - Nanoscale Res Lett (2011)

Bottom Line: After further prolonged reaction times, secondary irregular nanodiscs gradually grew vertically into regular nanodiscs.The electrochemical performances of the CuO nanodisc electrodes were evaluated in detail using cyclic voltammetry and galvanostatic cycling.Furthermore, we demonstrate that the incorporation of multiwalled carbon nanotubes enables the enhanced reversible capacities and capacity retention of CuO nanodisc electrodes on cycling by offering more efficient electron transport paths.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Materials Science and Engineering, Ajou University, Suwon 443-749, Korea. dwkim@ajou.ac.kr.

ABSTRACT
In this study, we report the high-yield synthesis of 2-dimensional cupric oxide (CuO) nanodiscs through dehydrogenation of 1-dimensional Cu(OH)2 nanowires at 60°C. Most of the nanodiscs had a diameter of approximately 500 nm and a thickness of approximately 50 nm. After further prolonged reaction times, secondary irregular nanodiscs gradually grew vertically into regular nanodiscs. These CuO nanostructures were characterized using X-ray diffraction, transmission electron microscopy, and Brunauer-Emmett-Teller measurements. The possible growth mechanism of the interlaced disc CuO nanostructures is systematically discussed. The electrochemical performances of the CuO nanodisc electrodes were evaluated in detail using cyclic voltammetry and galvanostatic cycling. Furthermore, we demonstrate that the incorporation of multiwalled carbon nanotubes enables the enhanced reversible capacities and capacity retention of CuO nanodisc electrodes on cycling by offering more efficient electron transport paths.

No MeSH data available.


Voltage profiles of CuO. Galvanostatic discharge/charge voltage profiles of CuO-interlaced nanodiscs at a rate of C/5.
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Figure 3: Voltage profiles of CuO. Galvanostatic discharge/charge voltage profiles of CuO-interlaced nanodiscs at a rate of C/5.

Mentions: The galvanostatic cycling characteristics of CuO-interlaced nanodiscs in the configuration of the CuO/Li half cell were investigated over a 0.01- to 3.0-V window at a rate of C/5 (based upon a theoretical capacity of 670 mA h g-1 by the conversion reaction, CuO + 2e- + 2Li+ ↔ Cu0 + Li2O), as shown in Figure 3. The first discharge and charge capacities were 971 and 699 mA h g-1, respectively. However, the capacity faded gradually from the subsequent cycle to a reversible capacity of 290 mA h g-1 after 20 cycles. Recently, Xiang et al. reported the synthesis of shuttle-shaped CuO particles with a length of 1 μm and a thickness of 100-200 nm at 90°C using Cu(Ac)2·H2O precursor, which have similar structures to our CuO-interlaced nanodiscs [8]. We found that shuttle-shaped CuO (cycled at a rate of C/10) and our CuO-interlaced nanodiscs (cycled at a rate of C/5) showed similar electrochemical performance. The BET surface area of CuO-interlaced nanodiscs was estimated to be a relatively large value, approximately 60 m2 g-1, but a significant impact on the electrochemical performance of this CuO-nanostructured electrode cannot be fully realized, possibly due to the aggregated CuO nanostructure (Figure 2f) and inhomogeneous mixing of conducting Super P carbon black with CuO nanostructures, which eventually increased the interparticle resistance, thereby degrading electrochemical performance [16,25,26]. This detrimental phenomenon may also have been caused by the significant volume change upon cycling [27].


Low-temperature synthesis of CuO-interlaced nanodiscs for lithium ion battery electrodes.

Seo SD, Jin YH, Lee SH, Shim HW, Kim DW - Nanoscale Res Lett (2011)

Voltage profiles of CuO. Galvanostatic discharge/charge voltage profiles of CuO-interlaced nanodiscs at a rate of C/5.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211491&req=5

Figure 3: Voltage profiles of CuO. Galvanostatic discharge/charge voltage profiles of CuO-interlaced nanodiscs at a rate of C/5.
Mentions: The galvanostatic cycling characteristics of CuO-interlaced nanodiscs in the configuration of the CuO/Li half cell were investigated over a 0.01- to 3.0-V window at a rate of C/5 (based upon a theoretical capacity of 670 mA h g-1 by the conversion reaction, CuO + 2e- + 2Li+ ↔ Cu0 + Li2O), as shown in Figure 3. The first discharge and charge capacities were 971 and 699 mA h g-1, respectively. However, the capacity faded gradually from the subsequent cycle to a reversible capacity of 290 mA h g-1 after 20 cycles. Recently, Xiang et al. reported the synthesis of shuttle-shaped CuO particles with a length of 1 μm and a thickness of 100-200 nm at 90°C using Cu(Ac)2·H2O precursor, which have similar structures to our CuO-interlaced nanodiscs [8]. We found that shuttle-shaped CuO (cycled at a rate of C/10) and our CuO-interlaced nanodiscs (cycled at a rate of C/5) showed similar electrochemical performance. The BET surface area of CuO-interlaced nanodiscs was estimated to be a relatively large value, approximately 60 m2 g-1, but a significant impact on the electrochemical performance of this CuO-nanostructured electrode cannot be fully realized, possibly due to the aggregated CuO nanostructure (Figure 2f) and inhomogeneous mixing of conducting Super P carbon black with CuO nanostructures, which eventually increased the interparticle resistance, thereby degrading electrochemical performance [16,25,26]. This detrimental phenomenon may also have been caused by the significant volume change upon cycling [27].

Bottom Line: After further prolonged reaction times, secondary irregular nanodiscs gradually grew vertically into regular nanodiscs.The electrochemical performances of the CuO nanodisc electrodes were evaluated in detail using cyclic voltammetry and galvanostatic cycling.Furthermore, we demonstrate that the incorporation of multiwalled carbon nanotubes enables the enhanced reversible capacities and capacity retention of CuO nanodisc electrodes on cycling by offering more efficient electron transport paths.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Materials Science and Engineering, Ajou University, Suwon 443-749, Korea. dwkim@ajou.ac.kr.

ABSTRACT
In this study, we report the high-yield synthesis of 2-dimensional cupric oxide (CuO) nanodiscs through dehydrogenation of 1-dimensional Cu(OH)2 nanowires at 60°C. Most of the nanodiscs had a diameter of approximately 500 nm and a thickness of approximately 50 nm. After further prolonged reaction times, secondary irregular nanodiscs gradually grew vertically into regular nanodiscs. These CuO nanostructures were characterized using X-ray diffraction, transmission electron microscopy, and Brunauer-Emmett-Teller measurements. The possible growth mechanism of the interlaced disc CuO nanostructures is systematically discussed. The electrochemical performances of the CuO nanodisc electrodes were evaluated in detail using cyclic voltammetry and galvanostatic cycling. Furthermore, we demonstrate that the incorporation of multiwalled carbon nanotubes enables the enhanced reversible capacities and capacity retention of CuO nanodisc electrodes on cycling by offering more efficient electron transport paths.

No MeSH data available.