Han Jiemin, Ma Yifei, Wang Mei, Li Linhan, Tong Zhaomin, Xiao Liantuan, Jia Suotang, Chen Xuyuan
State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China.
Faculty of Technology, Natural Sciences and Maritime Sciences, Department of Microsystems, University of Southeast Norway, Borre N-3184, Norway.
ACS Appl Mater Interfaces. 2021 Mar 17;13(10):12400-12407. doi: 10.1021/acsami.1c00544. Epub 2021 Mar 5.
Combining the advantages of a three-dimensional structure with intrinsic properties of graphene, vertical graphene (VG) synthesized by the plasma-enhanced chemical vapor deposition (PECVD) process has shown great promise to be applied to energy-storage electrodes. However, the practical application of the VG electrodes suffers from the limited height, which is mostly in a scale of few hundreds of nanometers, as shown in the previous studies. The reason for the unacceptable thin VG film deposition is believed to be the height saturation, stemming from the inevitable confluence of the VG flakes along with the deposition time. In this study, we developed an oxygen-assisted "trimming" process to eliminate the overfrondent graphene nanosheets thereby surmounting the saturation of the VG thickness during growth. In this approach, the height of the VGs reaches as high as 80 μm. Tested as supercapacitor electrodes, a desirable capacitance of 241.35 mF cm is obtained by the VG films, indicating the superior electrochemical properties and the potential for applications in energy storage. It is worth noting, this thickness is by no means the maximum that can be achieved with our synthesis technique and higher capacitance can be achieved by conducting the circulating deposition-correction process in our work.
通过等离子体增强化学气相沉积（PECVD）工艺合成的垂直石墨烯（VG）结合了三维结构的优势和石墨烯的固有特性，在应用于储能电极方面显示出巨大潜力。然而，如先前研究所表明的，VG电极的实际应用受到其有限高度的限制，该高度大多处于几百纳米的尺度。据信，不可接受的薄VG膜沉积的原因是高度饱和，这源于VG薄片随沉积时间的不可避免的汇合。在本研究中，我们开发了一种氧辅助“修剪”工艺，以消除过多的石墨烯纳米片，从而克服了VG生长过程中厚度的饱和问题。通过这种方法，VG的高度达到了80μm。作为超级电容器电极进行测试时，VG薄膜获得了241.35mF/cm的理想电容，表明其具有优异的电化学性能以及在储能领域的应用潜力。值得注意的是，这个厚度绝不是我们合成技术所能达到的最大值，通过在我们的工作中进行循环沉积-校正工艺可以实现更高的电容。
