Highly Flexible and Planar Supercapacitors Using Graphite Flakes/Polypyrrole in Polymer Lapping Film

Abstract

Flexible supercapacitor electrodes have been fabricated by simple fabrication technique using graphite nanoflakes on polymer lapping films as flexible substrate. An additional thin layer of conducting polymer polypyrrole over the electrode improved the surface conductivity and exhibited excellent electrochemical performances. Such capacitor films showed better energy density and power density with a maximum capacitance value of 37 mF cm(-2) in a half cell configuration using 1 M H2SO4 electrolyte, 23 mF cm(-2) in full cell, and 6 mF cm(-2) as planar cell configuration using poly(vinyl alcohol) (PVA)/phosphoric acid (H3PO4) solid state electrolyte. Moreover, the graphite nanoflakes/polypyrrole over polymer lapping film demonstrated good flexibility and cyclic stability.

Three‐Dimensional MoS2@CNT/RGO Network Composites for High‐Performance Flexible Supercapacitors

“…The discharging curvesa re relatively symmetrical to the corre- sponding charging counterpart, further indicatingt he good capacitivep roperties of the electrodes. [41] The areal capacitance of the MoS 2 @CNT/ RGO is also superior to many graphene (GN) based materials previously reported, such as GN/polypyrrole (115 mF cm À2 ), [42] RGO/TiO 2 (13.74 mF cm À2 ), [43] graphite flakes/polypyrrole (37 mF cm À2 ), [44] and the result is close to that of RGO/Mo 2 N (142 mF cm À2 ). The capacitance of the composite materials is superior to most metal sulfide-based/ carbon composites, such as MoS x /CFP (83.9 mF cm À2 ,C FP = carbon fibre paper), [16] VS 2 (4.76 mF cm À2 ) [9] ,a nd MoS 2 nanowall films (71mFcm À2 ).…”

“…The areal capacitance of the all-solid-state SC is 29.5 mF cm À2 at 0.1 mA cm À2 and remains constant at 20.4 mF cm À2 at 10 mA cm À2 (Figure 6c). [44,[55][56][57][58][59][60][61][62][63][64] approximately 10.5 W.T he excellent electrochemical performance of MoS 2 @CNT/RGO SC can be mainly attributed to the distinct 3D interconnected nanostructure of the flexible electrodes. The capacitance of the device corresponds to LIG-MoS 2 (14 mF cm À2 ,L IG = laser-induced graphene), [46] MoS 2 @S-rGO (6.56 mF cm À2 ), [47] MoS 2 @Ni(OH) 2 (14.07 mF cm À2 ), [48] MoS 2 nanoporous films (12.5 mF cm À2 ), [49] CFP/MoS x (41.96 mF cm À2 ), [41] MoS 2 /Si (8 mF cm À2 ) [50] MoS 2 @GN (11mFcm À2 ), [51] VOPO 4 /GN (8.36 mF cm À2 ), [52] and graphene membrane (3.3 mF cm À2 ).…”

“…(f) Ragone plots of the SC devicec ompared with otherl iteraturedata. [44,[55][56][57][58][59][60][61][62][63][64] approximately 10.5 W.T he excellent electrochemical performance of MoS 2 @CNT/RGO SC can be mainly attributed to the distinct 3D interconnected nanostructure of the flexible electrodes.…”

Highly flexible all-solid-state supercapacitors based on carbon nanotube/polypyrrole composite films and fibers

“…Energy storage devices (batteries, traditional capacitor and supercapacitor), which are the key parts to hinder the electronics to be smart, are required to have properties such as being lighter, thinner and flexible. In comparison with supercapacitors using liquid electrolyte, all-solid-state and flexible supercapacitors have excellent mechanical properties, such as being stretchable, twistable and compressible, [6,7] and there electrochemical performance can be maintained at even under significant deformation. [4,5] They have much higher energy density than the traditional capacitors.…”

General Interfacial Self‐Assembly Engineering for Patterning Two‐Dimensional Polymers with Cylindrical Mesopores on Graphene

“…It is notable that the features of CV curves (Figure 3d)a re well retained even at ah igh scan rate of 100 mV s À1 ,m anifesting high electrochemical reversibility.T he GCD profiles of mPPy/rGO-MSCs (Supporting Information, Figure S11), measured at different current densities,e xhibit approximate triangular form with small IR voltage drop.R emarkably, mPPy/rGO-MSCs deliver high areal capacitance (C A )o f 81 mF cm À2 and volumetric capacitance (C V )of102 Fcm À3 at 1mVs À1 (Figure 3e;t he calculations are given in the Supporting Information, pp S3,S4), which is superior to those of carbon-and conducting-polymer-based MSCs. [49][50][51] Meanwhile,t he resultant microdevice affords high capacitance (40 mF cm À2 ,50Fcm À3 )even when the scan rate is increased to 100 mV s À1 ,d emonstrative of exceptional rate capability. Moreover,m PPy/rGO-MSCs exhibit good cycling stability with 81 %c apacitance retention after 3500 charge/discharge cycles (Supporting Information, Figure S12).…”