TY - JOUR
T1 - Ultrahigh-rate supercapacitors with large capacitance based on edge oriented graphene coated carbonized cellulous paper as flexible freestanding electrodes
AU - Ren, Guofeng
AU - Li, Shiqi
AU - Fan, Zhao Xia
AU - Hoque, Md Nadim Ferdous
AU - Fan, Zhaoyang
N1 - Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2016
Y1 - 2016
N2 - Large-capacitance and ultrahigh-rate electrochemical supercapacitors (UECs) with frequency response up to kilohertz (kHz) range are reported using light, thin, and flexible freestanding electrodes. The electrode is formed by perpendicularly edge oriented multilayer graphene/thin-graphite (EOG) sheets grown radially around individual fibers in carbonized cellulous paper (CCP), with cellulous carbonization and EOG deposition implemented in one step. The resulted ∼10 μm thick EOG/CCP electrode is light and flexible. The oriented porous structure of EOG with large surface area, in conjunction with high conductivity of the electrode, ensures ultrahigh-rate performance of the fabricated cells, with large areal capacitance of 0.59 mF cm−2 and 0.53 mF cm−2 and large phase angle of −83° and −80° at 120 Hz and 1 kHz, respectively. Particularly, the hierarchical EOG/CCP sheet structure allows multiple sheets stacked together for thick electrodes with almost linearly increased areal capacitance while maintaining the volumetric capacitance nearly no degradation, a critical merit for developing practical faraday-scale UECs. 3-layers of EOG/CCP electrode achieved an areal capacitance of 1.5 mF cm−2 and 1.4 mF cm−2 at 120 Hz and 1 kHz, respectively. This demonstration moves a step closer to the goal of bridging the frequency/capacitance gap between supercapacitors and electrolytic capacitors.
AB - Large-capacitance and ultrahigh-rate electrochemical supercapacitors (UECs) with frequency response up to kilohertz (kHz) range are reported using light, thin, and flexible freestanding electrodes. The electrode is formed by perpendicularly edge oriented multilayer graphene/thin-graphite (EOG) sheets grown radially around individual fibers in carbonized cellulous paper (CCP), with cellulous carbonization and EOG deposition implemented in one step. The resulted ∼10 μm thick EOG/CCP electrode is light and flexible. The oriented porous structure of EOG with large surface area, in conjunction with high conductivity of the electrode, ensures ultrahigh-rate performance of the fabricated cells, with large areal capacitance of 0.59 mF cm−2 and 0.53 mF cm−2 and large phase angle of −83° and −80° at 120 Hz and 1 kHz, respectively. Particularly, the hierarchical EOG/CCP sheet structure allows multiple sheets stacked together for thick electrodes with almost linearly increased areal capacitance while maintaining the volumetric capacitance nearly no degradation, a critical merit for developing practical faraday-scale UECs. 3-layers of EOG/CCP electrode achieved an areal capacitance of 1.5 mF cm−2 and 1.4 mF cm−2 at 120 Hz and 1 kHz, respectively. This demonstration moves a step closer to the goal of bridging the frequency/capacitance gap between supercapacitors and electrolytic capacitors.
KW - AC filtering
KW - Cellulose
KW - Oriented graphene
KW - Supercapacitor
KW - Ultrahigh rate
UR - http://www.scopus.com/inward/record.url?scp=84979888149&partnerID=8YFLogxK
U2 - 10.1016/j.jpowsour.2016.06.021
DO - 10.1016/j.jpowsour.2016.06.021
M3 - Article
AN - SCOPUS:84979888149
VL - 325
SP - 152
EP - 160
JO - Journal of Power Sources
JF - Journal of Power Sources
SN - 0378-7753
ER -