Effect of Different Electrolytes on the Supercapacitor Behavior of Single and Multilayered Electrode Materials Based on Multiwalled Carbon Nanotube/Polyaniline Composite

Abstract

In the present study, the electropolymerization (template synthesis) and then fabrication of symmetrical supercapacitors based on single and multilayered multiwalled carbon nanotube/polyaniline (MWCNT/PA) is achieved. It is found that the morphology and capacitance values depend strongly on the nature and concentration of electrolytes. The presence of micro and mesopores on the MWCNTs provides the space for the deposition of PA on them. The extended conjugation results due to the overlapping of π electron cloud of sp2 hybridized carbon network of MWCNT with quinoid rings of three layers of PA doped with three dopants. This leads to the highest capacitance of 333 F g−1 and good charge–discharge cycling behavior with 85% charge retention at 1000 cycles for the symmetrical supercapacitor based on the multilayered composite material.

Polyaniline Nanotubes/Carbon Cloth Composite Electrode by Thermal Acid Doping for High-Performance Supercapacitors

“…PANI-ZIF-67-CC [18] 371 RGO/V 2 O 5 /PANI [24] 273 PANI/Silica Self-Aggregates [25] 218.75 PANI@Nanodiamond-Graphene [26] 150.20 Carbon Fiber/PANI [27] 350 Multiwalled Carbon Nanotube/PANI [28] 333 CC@PANI NTs-H (This work) 438 electrodes in Figure 4e, and the discharging time of former is also longer than latter in Figure 4f. The maximum gravimetric capacitance of CC@PANI NTs-H is 438 F g −1 , which are larger than that of CC@PANI NTs-R (276 F g −1 ), respectively.…”

“…The maximum gravimetric capacitance of CC@PANI NTs-H is 438 F g −1 , which are larger than that of CC@PANI NTs-R (276 F g −1 ), respectively. The values are superior to most similar electrodes [18,[24][25][26][27][28], as shown in Table 1. The better electrochemical performances of the CC@PANI NTs-H electrode in comparison with CC@PANI NTs-R can be attributed to acid doping at high temperature, which promotes the ordered structure of PANI and provides more sufficient protons [29].…”

Stereolithography-Derived Three-Dimensional Pyrolytic Carbon/Mn3O4 Nanostructures for Free-Standing Hybrid Supercapacitor Electrodes

“…It is worth mentioning that only a minor increase in the specific capacitance was observed with doubling of the concentration of a H 2 SO 4 solution from 0.5 to 1 M. This might be due to the decrease in the distance between the ions at higher concentrations and thereby their repulsions, which could limit the diffusion rate of protons to the electrode/electrolyte interface. 60 , 61 …”

“…It is worth mentioning that only a minor increase in the specific capacitance was observed with doubling of the concentration of a H 2 SO 4 solution from 0.5 to 1 M. This might be due to the decrease in the distance between the ions at higher concentrations and thereby their repulsions, which could limit the diffusion rate of protons to the electrode/electrolyte interface. 60,61 In the past, very diverse capacitance values have been reported for Mn 3 O 4 -based materials as SC electrodes. For instance, Dai et al reported a specific capacitance of 133 F g −1 for spinel Mn 3 O 4layered nanoarchitectures within an operational potential window of 0−0.9 V. 36 Dubal et al reported specific capacitances of 284 F g −1 for a Mn 3 O 4 thin film with triangular-shaped nanoparticles over a potential window of −0.1 to +0.9 V 62 and 398 F g −1 for vertically arranged stacked Mn 3 O 4 nanosheets in the same potential window.…”

“…The better electrochemical capacitive performance measured in a H 2 SO 4 solution might be related to the considerably higher ionic conductivity of SO 4 ̅ anions (160.0 S cm 2 mol –1 ) compared to that of ClO 4 ̅ anions (67.3 S cm 2 mol –1 ), which leads to higher mobility and transfer rate. It is worth mentioning that only a minor increase in the specific capacitance was observed with doubling of the concentration of a H 2 SO 4 solution from 0.5 to 1 M. This might be due to the decrease in the distance between the ions at higher concentrations and thereby their repulsions, which could limit the diffusion rate of protons to the electrode/electrolyte interface. , …”