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Alternating current line-filter based on electrochemical capacitor utilizing template-patterned graphene.

Wu Z, Li L, Lin Z, Song B, Li Z, Moon KS, Wong CP, Bai SL - Sci Rep (2015)

Bottom Line: In this work, graphene oxide (GO) is reduced by patterned metal interdigits at room temperature and used directly as the electrode material.In addition, it retains 97.2% of the initial capacitance after 10000 charge/discharge cycles.These outstanding performance characteristics of our device demonstrate its promising to replace the conventional AECs for ac line filtering.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Materials Science and Engineering, CAPT/HEDPS/LTCS, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Engineering, Peking University, Beijing 100871, China [2] School of Material Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245, USA.

ABSTRACT
Aluminum electrolytic capacitors (AECs) are widely used for alternating current (ac) line-filtering. However, their bulky size is becoming more and more incompatible with the rapid development of portable electronics. Here we report a scalable process to fabricate miniaturized graphene-based ac line-filters on flexible substrates at room temperature. In this work, graphene oxide (GO) is reduced by patterned metal interdigits at room temperature and used directly as the electrode material. The as-fabricated device shows a phase angle of -75.4° at 120 Hz with a specific capacitance of 316 µF/cm(2) and a RC time constant of 0.35 ms. In addition, it retains 97.2% of the initial capacitance after 10000 charge/discharge cycles. These outstanding performance characteristics of our device demonstrate its promising to replace the conventional AECs for ac line filtering.

No MeSH data available.


a) CV curves of the device at scan rates of 2, 5 and 8 V/s, respectively.(b) Stability performance measured with CD cycling at a current density of 1.3 mA/cm2. (c) Bode phase diagram of our device and AEC. (d) AC impedance spectrum of our device. The inset shows the high frequency region.
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f3: a) CV curves of the device at scan rates of 2, 5 and 8 V/s, respectively.(b) Stability performance measured with CD cycling at a current density of 1.3 mA/cm2. (c) Bode phase diagram of our device and AEC. (d) AC impedance spectrum of our device. The inset shows the high frequency region.

Mentions: Figure 2(a,b) shows the top and cross-section scanning electron microscopic (SEM) images of the freeze-dried rGO aerogel assembled on the metal interdigit of a silicon substrate. The as-reduced rGO sheets form a three-dimensional interconnected structure that attaches onto the metal interdigit instead of diffusing away. The sharp edges clearly maintain the original metal interdigital design and illustrate the conformal coating mechanism. Electrochemical tests were carried out to test the performance. Figure 3(a) shows the cyclic voltammetry (CV) curves at scan rates of 2, 5 and 8 V/s, which are approximately two orders of magnitude higher than those for conventional supercapacitors. The rectangular CV curves at high scan rates imply small series resistance and efficient EDLC attribute of the as-prepared rGO hydrogel electrode23. Figure 3(b) shows the cycling performance of the device. The capacitance retention is 97.2% after 10000 times of CD cycles at a current density of 0.58 mA/cm2. The good cycling performance of our device is highly desirable in real applications.


Alternating current line-filter based on electrochemical capacitor utilizing template-patterned graphene.

Wu Z, Li L, Lin Z, Song B, Li Z, Moon KS, Wong CP, Bai SL - Sci Rep (2015)

a) CV curves of the device at scan rates of 2, 5 and 8 V/s, respectively.(b) Stability performance measured with CD cycling at a current density of 1.3 mA/cm2. (c) Bode phase diagram of our device and AEC. (d) AC impedance spectrum of our device. The inset shows the high frequency region.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4470326&req=5

f3: a) CV curves of the device at scan rates of 2, 5 and 8 V/s, respectively.(b) Stability performance measured with CD cycling at a current density of 1.3 mA/cm2. (c) Bode phase diagram of our device and AEC. (d) AC impedance spectrum of our device. The inset shows the high frequency region.
Mentions: Figure 2(a,b) shows the top and cross-section scanning electron microscopic (SEM) images of the freeze-dried rGO aerogel assembled on the metal interdigit of a silicon substrate. The as-reduced rGO sheets form a three-dimensional interconnected structure that attaches onto the metal interdigit instead of diffusing away. The sharp edges clearly maintain the original metal interdigital design and illustrate the conformal coating mechanism. Electrochemical tests were carried out to test the performance. Figure 3(a) shows the cyclic voltammetry (CV) curves at scan rates of 2, 5 and 8 V/s, which are approximately two orders of magnitude higher than those for conventional supercapacitors. The rectangular CV curves at high scan rates imply small series resistance and efficient EDLC attribute of the as-prepared rGO hydrogel electrode23. Figure 3(b) shows the cycling performance of the device. The capacitance retention is 97.2% after 10000 times of CD cycles at a current density of 0.58 mA/cm2. The good cycling performance of our device is highly desirable in real applications.

Bottom Line: In this work, graphene oxide (GO) is reduced by patterned metal interdigits at room temperature and used directly as the electrode material.In addition, it retains 97.2% of the initial capacitance after 10000 charge/discharge cycles.These outstanding performance characteristics of our device demonstrate its promising to replace the conventional AECs for ac line filtering.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Materials Science and Engineering, CAPT/HEDPS/LTCS, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Engineering, Peking University, Beijing 100871, China [2] School of Material Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245, USA.

ABSTRACT
Aluminum electrolytic capacitors (AECs) are widely used for alternating current (ac) line-filtering. However, their bulky size is becoming more and more incompatible with the rapid development of portable electronics. Here we report a scalable process to fabricate miniaturized graphene-based ac line-filters on flexible substrates at room temperature. In this work, graphene oxide (GO) is reduced by patterned metal interdigits at room temperature and used directly as the electrode material. The as-fabricated device shows a phase angle of -75.4° at 120 Hz with a specific capacitance of 316 µF/cm(2) and a RC time constant of 0.35 ms. In addition, it retains 97.2% of the initial capacitance after 10000 charge/discharge cycles. These outstanding performance characteristics of our device demonstrate its promising to replace the conventional AECs for ac line filtering.

No MeSH data available.