posted on 2021-03-05, 19:34authored byJiemin Han, Yifei Ma, Mei Wang, Linhan Li, Zhaomin Tong, Liantuan Xiao, Suotang Jia, Xuyuan Chen
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–2 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.