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

Zhenkun Wu,Zhuo Li,Ziyin Lin,Kyoung-Sik Moon,Ching-Ping Wong,Bo Song,Shu-Lin Bai,Liyi Li

doi:10.1038/srep10983

Zhenkun Wu, Zhuo Li + Show 6 more

Open Access

https://doi.org/10.1038/srep10983

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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/cm2 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.

Highlights

Miller et al used a radio frequency plasma enhanced chemical vapor deposition method (PECVD) to fabricate vertically oriented graphene (VG) sheets as the active material and reported a phase angle of −82° at 120 Hz13
Lin et al designed interdigital micro-supercapacitors with graphene/vertically aligned carbon nanotube arrays (VACNT), which was grown by a conventional CVD approach, and achieved a phase angle of −81.5° at 120 Hz14
The high processing temperature is incompatible with flexible substrate that is critical for wearable electronics

Summary

Introduction

Miller et al used a radio frequency plasma enhanced chemical vapor deposition method (PECVD) to fabricate vertically oriented graphene (VG) sheets as the active material and reported a phase angle of −82° at 120 Hz13. Sheng et al electrochemically reduced graphene oxide (GO) on a gold foil and reported a phase angle of −84° at 120 Hz15. Most of these methods are not suitable for large scale production. The as-fabricated device shows a phase angle of −75.4° at 120 Hz with a specific capacitance of 316 μ F/cm[2] and a RC time constant of 0.35 ms. It retains 97.2% of the initial capacity after 10000 galvanostatic charge/discharge (CD) cycles

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Results

Conclusion