Supplementary Information for
Solid-State High Performance Flexible Supercapacitors Based
on Polypyrrole-MnO2-Carbon Fiber Hybrid Structure
Jiayou Tao,†1,2 Nishuang Liu,‡1 Wenzhen Ma,†1 Longwei Ding,1 Luying Li,1 Jun Su1 & Yihua
Gao‡1
1
Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for
Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology
(HUST), LuoyuRoad 1037, Wuhan 430074, P. R. China
2School
of Physics and Electronics, Hunan Institute of Science and Technology, Yueyang 414006,
P. R. China
Correspondence and requests for materials should be addressed to Y.H.G. (gaoyihua@hust.edu.cn) &
N.S.L. (nishuang_liu@foxmail.com )
1. The volume capacitance of the device can be calculated by the following equations:
C  I t U
(1)
CV  C V  I t (V U )
(2)
where C is the capacitance of the SC, I is the discharge current, Δt is the discharge
time, ΔU is the potential window (0.8 V) during the discharge process, CV is the
volume capacitance, and V is the volume of the fibers.
2. The energy density and average power density derived from the GCD of the device
can be calculated from the following equations:
DE  0.5CV  U 
DP  3600 DE t
2
(3)
(4)
where DE is the energy density, CV is the volume capacitance which can be obtained
through Eq. 2, ΔU is 0.8 V, DP is the average power density and Δt is the discharge
time.
Figure S1｜(a-g) SEM images of MnO2 nanoflakes of different deposition time: 1, 5,
10, 15, 20, 30, 45 min, respectively. (h) A SEM image of a cracked MnO2-CF. Scale
bars: 1 μm. This figure clearly revealed the growth process of MnO2 nanoflakes.
Figure S2︱A typical TEM image of MnO2 nanoflakes according to which we can
estimate the pore size.
Figure S3｜(a-f) SEM images of MnO2 nanoflakes of different deposition time: 0.5, 1,
1.5, 2, 2.5, 3 min, respectively. Scale bars: 1 μm. This figure clearly revealed the
growth process of PPy coating on MnO2 nanoflakes.
Figure S4｜(a) a SEM image of the cross section of a PPy-MnO2-CF, the inset was a
partial enlarged view of the cross section. (b) a typical EDS plot of the PPy-MnO2-CF
cross section, in which Cu signal came from the sample stage and N signal came from
PPy. (c) the molar ratio of Mn to C atom vs MnO2 deposition time (1, 5, 10, 15, 20,
30, 45 min). (d) a plot of the molar ratio of N to Mn atom vs PPy deposition time (0.5,
1, 1.5, 2, 2.5, 3 min), in which all the MnO2 deposition time was constant of 15 min.
(e) the weight ratio of C and MnO2 vs MnO2 deposition time. (f) the weight ratio of C,
MnO2 and PPy vs PPy deposition time, MnO2 deposition time is constant of 15 min.
Figure (c), (d), (e) and (f) revealed the variation tendency of the composition of the
electrode materials with different deposition time roughly.