scholarly journals Achieving Ultrahigh Cycling Stability and Extended Potential Window for Supercapacitors through Asymmetric Combination of Conductive Polymer Nanocomposite and Activated Carbon

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1678 ◽  
Author(s):  
Gul ◽  
Shah ◽  
Bilal
Keyword(s):  
Graphene Oxide ◽  
Activated Carbon ◽  
Charge Transfer ◽  
Energy Density ◽  
Specific Capacitance ◽  
Power Density ◽  
Current Density ◽  
Coulombic Efficiency ◽  
Cycling Stability ◽  
Transfer Resistance

Conducting polymers and carbon-based materials such as graphene oxide (GO) and activated carbon (AC) are the most promising capacitive materials, though both offer charge storage through different mechanisms. However, their combination can lead to some unusual results, offering improvement in certain properties in comparison with the individual materials. Cycling stability of supercapacitors devices is often a matter of concern, and extensive research is underway to improve this phenomena of supercapacitive devices. Herein, a high-performance asymmetric supercapacitor device was fabricated using graphene oxide–polyaniline (GO@PANI) nanocomposite as positive electrode and activated carbon (AC) as negative electrode. The device showed 142 F g-1 specific capacitance at 1 A g-1 current density with capacitance retention of 73.94% at higher current density (10 A g-1). Most importantly, the device exhibited very high electrochemical cycling stability. It retained 118.6% specific capacitance of the starting value after 10,000 cycles at 3 Ag-1 and with coulombic efficiency of 98.06 %, indicating great potential for practical applications. Very small solution resistance (Rs, 0.640 Ω) and charge transfer resistance (Rct, 0.200 Ω) were observed hinting efficient charge transfer and fast ion diffusion. Due to asymmetric combination, potential window was extended to 1.2 V in aqueous electrolyte, as a result higher energy density (28.5 Wh kg-1) and power density of 2503 W kg-1 were achieved at the current density 1 Ag-1. It also showed an aerial capacitance of 57 mF cm-2 at current 3.2 mA cm-2. At this current density, its energy density was maximum (0.92 mWh cm-2) with power density (10.47 W cm-2).

scholarly journals One-Step Hydrothermal Synthesis of a CoTe@rGO Electrode Material for Supercapacitors

2021 ◽  
Author(s):  
Tianrui Wang ◽  
Yupeng Su ◽  
Mi Xiao ◽  
Meilian Zhao ◽  
Tingwu Zhao ◽  
...  
Keyword(s):  
Energy Density ◽  
Specific Capacitance ◽  
Power Density ◽  
Current Density ◽  
Electrode Material ◽  
High Energy ◽  
Cycling Stability ◽  
High Energy Density ◽  
One Step ◽  
Charge Discharge

AbstractCoTe@reduced graphene oxide (CoTe@rGO) electrode materials for supercapacitors were prepared by a one-step hydrothermal method in this paper. Compared with that of pure CoTe, the electrochemical performance of CoTe@rGO was significantly improved. The results showed that the optimal CoTe@rGO electrode material has a remarkably high specific capacitance of 810.6 F/g at a current density of 1 A/g. At 5 A/g, the synthesized material retained 77.2% of its initial capacitance even after 5000 charge/discharge cycles, thereby demonstrating good cycling stability. Moreover, even at a high current density of 20 A/g, the composite electrode retained 79.0% of its specific capacitance at 1 A/g, thus confirming its excellent rate performance. An asymmetric supercapacitor (ASC) with a wider potential window and higher energy density was assembled by using 3 M KOH as the electrolyte, the CoTe@rGO electrode as the positive electrode, and active carbon as the negative electrode. The operating voltage of the supercapacitor could be increased to 1.6 V, and its specific capacitance could reach 112.6 F/g at 1 A/g. The specific capacitance retention rate of the fabricated supercapacitor after 5000 charge/discharge cycles at 5 A/g was 87.1%, which confirms its excellent cycling stability. In addition, the ASC revealed a high energy density of 40.04 W·h/kg at a power density of 799.91 W/kg and a high power density of 4004.93 W/kg at an energy density of 33.43 W·h/kg. These results collectively show that CoTe@rGO materials have broad application prospects.

scholarly journals Fabrication of Eco-Friendly Solid-State Symmetric Ultracapacitor Device Based on Co-Doped PANI/GO Composite

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1315 ◽  
Author(s):  
Gul ◽  
Shah ◽  
Bilal
Keyword(s):  
Solid State ◽  
Energy Density ◽  
Specific Capacitance ◽  
Power Density ◽  
Current Density ◽  
Sulfonic Acid ◽  
Rate Capability ◽  
Transfer Resistance ◽  
Benzene Sulfonic Acid ◽  
Co Doped

An eco-friendly solid-state symmetric ultracapacitor (Uc) device was fabricated using a polyaniline graphene oxide composite co-doped with sulfuric acid (H2SO4) and dodecyl benzene sulfonic acid (DBSA) or camphor sulfonic acid (CSA), as electrode material utilizing gold sheets as current collectors. The device showed specific capacitance value of 150 F/g at 1 A/g current density, with a capacitance retention value of 93.33% at higher current density (10 A/g), indicating a high rate capability. An energy density of 15.30 Whkg−1 with a power density of 1716 Wkg−1 was obtained at the current density of 1 A/g. The values of areal capacitance, power density, and energy density, achieved at the current density of 5 mAcm−2, were 97.38 mFcm−2, 9.93 mWhcm−2, and 1.1 Wcm−2, respectively. Additionally, the device showed very low solution and charge transfer resistance (0.885 Ω and 0.475 Ω, respectively). A device was also fabricated utilizing copper as current collector; however, a lower value of specific capacitance (82 F/g) was observed in this case.

scholarly journals Na0.76V6O15/Activated Carbon Hybrid Cathode for High-Performance Lithium-Ion Capacitors

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 122
Author(s):  
Renwei Lu ◽  
Xiaolong Ren ◽  
Chong Wang ◽  
Changzhen Zhan ◽  
Ding Nan ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Energy Density ◽  
Power Density ◽  
Cathode Materials ◽  
Low Cost ◽  
Lithium Ion ◽  
High Energy ◽  
Cycling Stability ◽  
High Energy Density ◽  
Artificial Graphite

Lithium-ion hybrid capacitors (LICs) are regarded as one of the most promising next generation energy storage devices. Commercial activated carbon materials with low cost and excellent cycling stability are widely used as cathode materials for LICs, however, their low energy density remains a significant challenge for the practical applications of LICs. Herein, Na0.76V6O15 nanobelts (NaVO) were prepared and combined with commercial activated carbon YP50D to form hybrid cathode materials. Credit to the synergism of its capacitive effect and diffusion-controlled faradaic effect, NaVO/C hybrid cathode displays both superior cyclability and enhanced capacity. LICs were assembled with the as-prepared NaVO/C hybrid cathode and artificial graphite anode which was pre-lithiated. Furthermore, 10-NaVO/C//AG LIC delivers a high energy density of 118.9 Wh kg−1 at a power density of 220.6 W kg−1 and retains 43.7 Wh kg−1 even at a high power density of 21,793.0 W kg−1. The LIC can also maintain long-term cycling stability with capacitance retention of approximately 70% after 5000 cycles at 1 A g−1. Accordingly, hybrid cathodes composed of commercial activated carbon and a small amount of high energy battery-type materials are expected to be a candidate for low-cost advanced LICs with both high energy density and power density.

scholarly journals Electrochemical properties of kenaf-based activated carbon monolith for supercapacitor electrode applications

RSC Advances ◽  
2021 ◽  
Vol 11 (61) ◽  
pp. 38515-38522
Author(s):  
Han Yul Park ◽  
Minhu Huang ◽  
Tae-Ho Yoon ◽  
Kyung Hun Song
Keyword(s):  
Activated Carbon ◽  
Energy Density ◽  
Electrochemical Properties ◽  
Specific Capacitance ◽  
Power Density ◽  
Supercapacitor Electrode ◽  
Cycling Test ◽  
Carbon Monolith ◽  
Activated Carbon Monolith

Monolithic carbon from kenaf-based fiber for supercapacitor electrode application provided a specific capacitance of 212 F g−1via GCD at 1 A g−1, converting to an energy density of 6 W h kg−1 at the power density of 215 W kg−1 as well as 95.9% retention upon 5000 cycling test.

scholarly journals An Ultra-High-Energy Density Supercapacitor; Fabrication Based on Thiol-functionalized Graphene Oxide Scrolls

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 148 ◽  
Author(s):  
Janardhanan. Rani ◽  
Ranjith Thangavel ◽  
Se-I Oh ◽  
Yun Lee ◽  
Jae-Hyung Jang
Keyword(s):  
Electrical Conductivity ◽  
Graphene Oxide ◽  
Energy Density ◽  
Power Density ◽  
Current Density ◽  
Electrode Materials ◽  
High Energy ◽  
High Energy Density ◽  
Functionalized Graphene Oxide ◽  
A Current

Present state-of-the-art graphene-based electrodes for supercapacitors remain far from commercial requirements in terms of high energy density. The realization of high energy supercapacitor electrodes remains challenging, because graphene-based electrode materials are synthesized by the chemical modification of graphene. The modified graphene electrodes have lower electrical conductivity than ideal graphene, and limited electrochemically active surface areas due to restacking, which hinders the access of electrolyte ions, resulting in a low energy density. In order to solve the issue of restacking and low electrical conductivity, we introduce thiol-functionalized, nitrogen-doped, reduced graphene oxide scrolls as the electrode materials for an electric double-layer supercapacitor. The fabricated supercapacitor exhibits a very high energy/power density of 206 Wh/kg (59.74 Wh/L)/496 W/kg at a current density of 0.25 A/g, and a high power/energy density of 32 kW/kg (9.8 kW/L)/9.58 Wh/kg at a current density of 50 A/g; it also operates in a voltage range of 0~4 V with excellent cyclic stability of more than 20,000 cycles. By suitably combining the scroll-based electrode and electrolyte material, this study presents a strategy for electrode design for next-generation energy storage devices with high energy density without compromising the power density.

scholarly journals In Situ Fabrication of Activated Carbon from a Bio-Waste Desmostachya bipinnata for the Improved Supercapacitor Performance

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Gopal Krishna Gupta ◽  
Pinky Sagar ◽  
Sumit Kumar Pandey ◽  
Monika Srivastava ◽  
A. K. Singh ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Energy Density ◽  
Power Density ◽  
Supercapacitor Electrode ◽  
In Situ Fabrication ◽  
Transmission Electron ◽  
Good Energy ◽  
Supercapacitor Performance ◽  
Operating Potential

AbstractHerein, we demonstrate the fabrication of highly capacitive activated carbon (AC) using a bio-waste Kusha grass (Desmostachya bipinnata), by employing a chemical process followed by activation through KOH. The as-synthesized few-layered activated carbon has been confirmed through X-ray powder diffraction, transmission electron microscopy, and Raman spectroscopy techniques. The chemical environment of the as-prepared sample has been accessed through FTIR and UV–visible spectroscopy. The surface area and porosity of the as-synthesized material have been accessed through the Brunauer–Emmett–Teller method. All the electrochemical measurements have been performed through cyclic voltammetry and galvanometric charging/discharging (GCD) method, but primarily, we focus on GCD due to the accuracy of the technique. Moreover, the as-synthesized AC material shows a maximum specific capacitance as 218 F g−1 in the potential window ranging from − 0.35 to + 0.45 V. Also, the AC exhibits an excellent energy density of ~ 19.3 Wh kg−1 and power density of ~ 277.92 W kg−1, respectively, in the same operating potential window. It has also shown very good capacitance retention capability even after 5000th cycles. The fabricated supercapacitor shows a good energy density and power density, respectively, and good retention in capacitance at remarkably higher charging/discharging rates with excellent cycling stability. Henceforth, bio-waste Kusha grass-derived activated carbon (DP-AC) shows good promise and can be applied in supercapacitor applications due to its outstanding electrochemical properties. Herein, we envision that our results illustrate a simple and innovative approach to synthesize a bio-waste Kusha grass-derived activated carbon (DP-AC) as an emerging supercapacitor electrode material and widen its practical application in electrochemical energy storage fields.

scholarly journals Nanoporous Activated Carbon Derived from Rice Husk for High Performance Supercapacitor

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Huaxing Xu ◽  
Biao Gao ◽  
Hao Cao ◽  
Xueyang Chen ◽  
Ling Yu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Capacitance ◽  
Current Density ◽  
Average Pore Size ◽  
Nanoporous Carbon ◽  
Cycle Life ◽  
Potential Candidate ◽  
Average Pore ◽  
Nanoporous Activated Carbon

Nanoporous activated carbon material was produced from the waste rice husks (RHs) by precarbonizing RHs and activating with KOH. The morphology, structure, and specific surface area were investigated. The nanoporous carbon has the average pore size of 2.2 nm and high specific area of 2523.4 m2 g−1. The specific capacitance of the nanoporous carbon is calculated to be 250 F g−1at the current density of 1 A g−1and remains 80% for 198 F g−1at the current density of 20 A g−1. The nanoporous carbon electrode exhibits long-term cycle life and could keep stable capacitance till 10,000 cycles. The consistently high specific capacitance, rate capacity, and long-term cycle life ability makes it a potential candidate as electrode material for supercapacitor.

scholarly journals Carbon-Coated SiO2 Composites as Promising Anode Material for Li-Ion Batteries

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4531
Author(s):  
Mihaela-Ramona Buga ◽  
Adnana Alina Spinu-Zaulet ◽  
Cosmin Giorgian Ungureanu ◽  
Raul-Augustin Mitran ◽  
Eugeniu Vasile ◽  
...  
Keyword(s):  
Anode Material ◽  
Photoelectron Spectroscopy ◽  
Coulombic Efficiency ◽  
Cycling Stability ◽  
Li Ion Batteries ◽  
Transfer Resistance ◽  
Promising Alternative ◽  
X Ray ◽  
Carbon Coated ◽  
Li Ion

Porous silica-based materials are a promising alternative to graphite anodes for Li-ion batteries due to their high theoretical capacity, low discharge potential similar to pure silicon, superior cycling stability compared to silicon, abundance, and environmental friendliness. However, several challenges prevent the practical application of silica anodes, such as low coulombic efficiency and irreversible capacity losses during cycling. The main strategy to tackle the challenges of silica as an anode material has been developed to prepare carbon-coated SiO2 composites by carbonization in argon atmosphere. A facile and eco-friendly method of preparing carbon-coated SiO2 composites using sucrose is reported herein. The carbon-coated SiO2 composites were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetry, transmission and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, cyclic voltammetry, and charge–discharge cycling. A C/SiO2-0.085 M calendered electrode displays the best cycling stability, capacity of 714.3 mAh·g−1, and coulombic efficiency as well as the lowest charge transfer resistance over 200 cycles without electrode degradation. The electrochemical performance improvement could be attributed to the positive effect of the carbon thin layer that can effectively diminish interfacial impedance.

scholarly journals Electrochemical Performance of Aluminum Doped Ni1−xAlxCo2O4 Hierarchical Nanostructure: Experimental and Theoretical Study

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1750
Author(s):  
Deepa Guragain ◽  
Romakanta Bhattarai ◽  
Jonghyun Choi ◽  
Wang Lin ◽  
Ram Krishna Gupta ◽  
...  
Keyword(s):  
Energy Density ◽  
Electrochemical Performance ◽  
Band Gap ◽  
Specific Capacitance ◽  
Surface Area ◽  
Power Density ◽  
High Power ◽  
Energy Band ◽  
High Specific Capacitance ◽  
High Power Density

For electrochemical supercapacitors, nickel cobaltite (NiCo2O4) has emerged as a new energy storage material. The electrocapacitive performance of metal oxides is significantly influenced by their morphology and electrical characteristics. The synthesis route can modulate the morphological structure, while their energy band gaps and defects can vary the electrical properties. In addition to modifying the energy band gap, doping can improve crystal stability and refine grain size, providing much-needed surface area for high specific capacitance. This study evaluates the electrochemical performance of aluminum-doped Ni1−xAlxCo2O4 (0 ≤ x ≤ 0.8) compounds. The Ni1−xAlxCo2O4 samples were synthesized through a hydrothermal method by varying the Al to Ni molar ratio. The physical, morphological, and electrochemical properties of Ni1−xAlxCo2O4 are observed to vary with Al3+ content. A morphological change from urchin-like spheres to nanoplate-like structures with a concomitant increase in the surface area, reaching up to 189 m2/g for x = 0.8, was observed with increasing Al3+ content in Ni1−xAlxCo2O4. The electrochemical performance of Ni1−xAlxCo2O4 as an electrode was assessed in a 3M KOH solution. The high specific capacitance of 512 F/g at a 2 mV/s scan rate, 268 F/g at a current density of 0.5 A/g, and energy density of 12.4 Wh/kg was observed for the x = 0.0 sample, which was reduced upon further Al3+ substitution. The as-synthesized Ni1−xAlxCo2O4 electrode exhibited a maximum energy density of 12.4 W h kg−1 with an outstanding high-power density of approximately 6316.6 W h kg−1 for x = 0.0 and an energy density of 8.7 W h kg−1 with an outstanding high-power density of approximately 6670.9 W h kg−1 for x = 0.6. The capacitance retention of 97% and 108.52% and the Coulombic efficiency of 100% and 99.24% were observed for x = 0.0 and x = 0.8, respectively. First-principles density functional theory (DFT) calculations show that the band-gap energy of Ni1−xAlxCo2O4 remained largely invariant with the Al3+ substitution for low Al3+ content. Although the capacitance performance is reduced upon Al3+ doping, overall, the Al3+ doped Ni1−xAlxCo2O4 displayed good energy, powder density, and retention performance. Thus, Al3+ could be a cost-effective alternative in replacing Ni with the performance trade off.

Sign in / Sign up

Export Citation Format

Share Document