Asymmetric supercapacitor of functionalised electrospun carbon fibers/poly(3,4-ethylenedioxythiophene)/manganese oxide//activated carbon with superior electrochemical performance

Abstract

Asymmetric supercapacitors (ASC) have shown a great potential candidate for high-performance supercapacitor due to their wide operating potential which can remarkably enhance the capacitive behaviour. In present work, a novel positive electrode derived from functionalised carbon nanofibers/poly(3,4-ethylenedioxythiophene)/manganese oxide (f-CNFs/PEDOT/MnO2) was prepared using a multi-step route and activated carbon (AC) was fabricated as a negative electrode for ASC. A uniform distribution of PEDOT and MnO2 on f-CNFs as well as porous granular of AC are well-observed in FESEM. The assembled f-CNFs/PEDOT/MnO2//AC with an operating potential of 1.6 V can achieve a maximum specific capacitance of 537 F/g at a scan rate of 5 mV/s and good cycling stability (81.06% after cycling 8000 times). Furthermore, the as-prepared ASC exhibited reasonably high specific energy of 49.4 Wh/kg and low charge transfer resistance (Rct) of 2.27 Ω, thus, confirming f-CNFs/PEDOT/MnO2//AC as a promising electrode material for the future energy storage system.

Ultra-High Energy Density Hybrid Supercapacitors Using MnO2/Reduced Graphene Oxide Hybrid Nanoscrolls

“…It also delivered an energy density of 42.77 Wh/kg at a specific power density of 30,800 W/kg. Our GMS/AC cell’s energy density values are very high compared with those of other reported values of graphene-based hybrid structures [ 19 , 20 , 21 ]. The cycling performance of the GMS/AC cell suggests that the cell maintained 92% of its initial capacitance even after 10,000 cycles at a current density of 5 A/g, indicating an excellent and stable cycling performance.…”

“…The calculated ESR of the GMS/AC cell was 4 Ω. It is worth mentioning that the ESR of 4 Ω of our GMS cell is lower than that of other reported values for rGO-based electrodes such as the MnO 2 –Au nanofiber-based supercapacitor electrode (22.52 Ω) [ 34 ], the carbon nanotube–MnO 2 electrode-based supercapacitor (21.8 Ω) [ 20 ], the carbon fiber–MnO 2 electrode-based supercapacitor (35.58 Ω) [ 19 ], and the Na-doped MnO 2 nanosheets-carbon nanotube fiber electrode-based supercapacitor (8.7 Ω) [ 35 ]. The charge–transfer resistance (R ct ) resulting from the diffusion of electrons towards the electrode materials can be estimated from the semicircle diameter.…”

“…The Ragone plots of the recently reported graphene-based hybrid supercapacitors are compared to those of the proposed GMS/AC cell and are shown in Figure 6 b. The gravimetric energy density of the GMS/AC cell was higher than those of other very recently reported devices, such as the carbon nanotube–MnO 2 supercapacitor (42 Wh/kg) [ 20 ], the carbon fiber–MnO 2 supercapacitor (49.4 Wh/kg) [ 19 ], the MnO 2 @CNTs/Ni network-based symmetrical supercapacitor (94.4 Wh/kg) [ 21 ], the graphene/MnO 2 nanoparticle hydrogel-based asymmetric supercapacitor (21.2 Wh/kg) [ 49 ], the conjugated indole-based macromolecule (30 Wh/kg) [ 50 ], the graphene/RuO 2 hybrid capacitor (20.1 Wh/kg) [ 51 ], rGO/mixed-valence MnO 2 composite (50 Wh/kg) [ 52 ], GS/Ni(OH) 2 nanoplates (53 Wh/kg) [ 46 ], thermally reduced GO supercapacitors (62.5 Wh/kg) [ 43 ], porous Ni 3 S 2 /CoNi 2 S 4 three-dimensional-network structure (62.2 Wh/kg) [ 53 ], asymmetric supercapacitors based on ionic liquid complex intercalated rGO (67.8 Wh/kg) [ 48 ], highly graphitic carbon–tipped MnO 2 /mesoporous carbon/MnO 2 hybrid nanowires (37 Wh/kg) [ 45 ], ionic-liquid-assisted Cu 2 O nanoparticles/multi-walled carbon nanotube nanocomposite (64.2 Wh/kg) [ 47 ], and mixed-valence sulfur-doped V 6 O 13−x (45 Wh/kg) [ 44 ]. Thus, the excellent performance of the GMS/AC cell will find suitable applications that demand high energy density storage devices.…”

Progress in Conducting Polymer‐Based Electrospun fibers for Supercapacitor Applications: A Review

“…Muhammad Abdah and co-workers [78] fabricated an asymmetric supercapacitor with functionalised carbon nanofiber/ poly(3,4-ethylenedioxythiophene)/manganese oxide (f-CNF/PE-DOT/MnO 2 ) as the positive electrode and activated carbon as the negative electrode. Due to the strong synergistic effect of the composite, the device thus obtained delivered a specific capacitance of 537 F g À 1 at a scan rate of 5 mV s À 1 in a wide potential window of 1.6 V.…”

Vertically Aligned Conductive Polymeric Nanotubes Grown on Percolated Multiwalled Carbon Nanotube Films for Supercapacitor Electrodes

“…A small deviation is observed in the curves at the discharge process, probably due to the faradic reactions in the PEDOT NTs during the discharging process. 47 The specific capacitance vs discharge current is plotted in Figure 5c, showing that the PEDOT@CNTs electrodes have a high capacitance of 250 F/g at 2 A/g due to the large active area achieved when the solution penetrates the hollow structure of the NTs and reaches the CPNT/CNT composite in the interspaces of the polymeric nanotubes. Figure S6 shows a scheme of the capacitance effect in the polymeric nanotube system in contact with the H 2 SO 4 electrolyte due to the penetration of [SO 4 ] −2 ions in the hollow spaces of the polymeric nanotubes.…”