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

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.

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Fabrication of Hierarchical NiMoO4/NiMoO4 Nanoflowers on Highly Conductive Flexible Nickel Foam Substrate as a Capacitive Electrode Material for Supercapacitors with Enhanced Electrochemical Performance

Energies ◽

10.3390/en12061143 ◽

2019 ◽

Vol 12 (6) ◽

pp. 1143 ◽

Cited By ~ 6

Author(s):

Anil Yedluri ◽

Tarugu Anitha ◽

Hee-Je Kim

Keyword(s):

Energy Density ◽

Electrochemical Performance ◽

Specific Capacitance ◽

Electrode Material ◽

High Performance ◽

Nickel Foam ◽

High Specific Capacitance ◽

High Energy ◽

High Energy Density ◽

Charge Discharge

Hierarchical NiMoO4/NiMoO4 nanoflowers were fabricated on highly conductive flexible nickel foam (NF) substrates using a facile hydrothermal method to achieve rapid charge-discharge ability, high energy density, long cycling lifespan, and higher flexibility for high-performance supercapacitor electrode materials. The synthesized composite electrode material, NF/NiMoO4/NiMoO4 with a nanoball-like NF/NiMoO4 structure on a NiMoO4 surface over a NF substrate, formed a three-dimensional interconnected porous network for high-performance electrodes. The novel NF/NiMoO4/NiMoO4 nanoflowers not only enhanced the large surface area and increased the electrochemical activity, but also provided an enhanced rapid ion diffusion path and reduced the charge transfer resistance of the entire electrode effectively. The NF/NiMoO4/NiMoO4 composite exhibited significantly improved supercapacitor performance in terms of a sustained cycling life, high specific capacitance, rapid charge-discharge capability, high energy density, and good rate capability. Electrochemical analysis of the NF/NiMoO4/NiMoO4 nanoflowers fabricated on the NF substrate revealed ultra-high electrochemical performance with a high specific capacitance of 2121 F g−1 at 12 mA g−1 in a 3 M KOH electrolyte and 98.7% capacitance retention after 3000 cycles at 14 mA g−1. This performance was superior to the NF/NiMoO4 nanoball electrode (1672 F g−1 at 12 mA g−1 and capacitance retention 93.4% cycles). Most importantly, the SC (NF/NiMoO4/NiMoO4) device displayed a maximum energy density of 47.13 W h kg−1, which was significantly higher than that of NF/NiMoO4 (37.1 W h kg−1). Overall, the NF/NiMoO4/NiMoO4 composite is a suitable material for supercapacitor applications.

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High Energy Density Asymmetric Supercapacitor Based on NiCo2S4/CNTs Hybrid and Carbon Nanotube Paper Electrodes

Journal of Molecular and Engineering Materials ◽

10.1142/s2251237319500047 ◽

2019 ◽

Vol 07 (01n02) ◽

pp. 1950004 ◽

Cited By ~ 4

Author(s):

Muhammad Sajjad ◽

Xu Chen ◽

Chunxin Yu ◽

Linlin Guan ◽

Shuyu Zhang ◽

...

Keyword(s):

Carbon Nanotube ◽

Energy Density ◽

Specific Capacitance ◽

Current Density ◽

Electrode Materials ◽

High Energy ◽

Hybrid Nanostructures ◽

High Energy Density ◽

Asymmetric Supercapacitor ◽

Charge Discharge

NiCo2S4/CNTs (NCS/CNTs) hybrid nanostructures have been synthesized by a facile one-step solvothermal method with varying content of CNTs. The structure and morphology of the synthesized NCS/CNTs hybrid revealed the formation of platelets anchored on the CNT matrix. When evaluated as electrode materials for supercapacitor, the as-synthesized NCS/CNT-1 hybrid (with 1% of CNT) manifested remarkable specific capacitance of 1690[Formula: see text]F[Formula: see text]g[Formula: see text] at the current density of 5[Formula: see text]A[Formula: see text]g[Formula: see text]. More importantly, an asymmetric supercapacitor (ASC) assembled based on NCS/CNT-1 as positive electrode and carbon nanotube paper (CNP) as a negative electrode delivered high energy density of 58[Formula: see text]Wh[Formula: see text]kg[Formula: see text] under power density of 8[Formula: see text]kW[Formula: see text]kg[Formula: see text]. Furthermore, the ASC device exhibited high cycling stability and 77.7% of initial specific capacitance retention after 7000 charge–discharge cycles at a current density of 8[Formula: see text]A[Formula: see text]g[Formula: see text]. The large enhancement in the electrochemical performance is attributed to the benefits of the nanostructured architecture, including good mechanical stability, high electrical conductivity as well as buffering for the volume changes during charge–discharge process. These convincing results show that NCS/CNTs hybrid nanostructures are promising electrode materials for high energy density supercapacitors (SCs).

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

Materials ◽

10.3390/ma14010122 ◽

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.

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Glycerolized Li+ Ion Conducting Chitosan-Based Polymer Electrolyte for Energy Storage EDLC Device Applications with Relatively High Energy Density

Polymers ◽

10.3390/polym12061433 ◽

2020 ◽

Vol 12 (6) ◽

pp. 1433 ◽

Cited By ~ 17

Author(s):

Ahmed S. F. M. Asnawi ◽

Shujahadeen B. Aziz ◽

Muaffaq M. Nofal ◽

Muhamad H. Hamsan ◽

Mohamad A. Brza ◽

...

Keyword(s):

Energy Density ◽

Polymer Electrolyte ◽

Specific Capacitance ◽

Power Density ◽

High Specific Capacitance ◽

High Energy ◽

High Energy Density ◽

Equivalent Series Resistance ◽

Ion Conducting ◽

High Dielectric

In this study, the solution casting method was employed to prepare plasticized polymer electrolytes of chitosan (CS):LiCO2CH3:Glycerol with electrochemical stability (1.8 V). The electrolyte studied in this current work could be established as new materials in the fabrication of EDLC with high specific capacitance and energy density. The system with high dielectric constant was also associated with high DC conductivity (5.19 × 10−4 S/cm). The increase of the amorphous phase upon the addition of glycerol was observed from XRD results. The main charge carrier in the polymer electrolyte was ion as tel (0.044) < tion (0.956). Cyclic voltammetry presented an almost rectangular plot with the absence of a Faradaic peak. Specific capacitance was found to be dependent on the scan rate used. The efficiency of the EDLC was observed to remain constant at 98.8% to 99.5% up to 700 cycles, portraying an excellent cyclability. High values of specific capacitance, energy density, and power density were achieved, such as 132.8 F/g, 18.4 Wh/kg, and 2591 W/kg, respectively. The low equivalent series resistance (ESR) indicated that the EDLC possessed good electrolyte/electrode contact. It was discovered that the power density of the EDLC was affected by ESR.

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ZnS–Ni7S6 Nanosheet Arrays Wrapped with Nanopetals of Ni(OH)2 as a Novel Core–Shell Electrode Material for Asymmetric Supercapacitors with High Energy Density and Cycling Stability Performance

ACS Applied Materials & Interfaces ◽

10.1021/acsami.0c10638 ◽

2020 ◽

Vol 12 (42) ◽

pp. 47377-47388 ◽

Cited By ~ 3

Author(s):

Ghuzanfar Saeed ◽

Parthasarathi Bandyopadhyay ◽

Sachin Kumar ◽

Nam Hoon Kim ◽

Joong Hee Lee

Keyword(s):

Energy Density ◽

Electrode Material ◽

High Energy ◽

Cycling Stability ◽

High Energy Density ◽

Core Shell ◽

Asymmetric Supercapacitors ◽

Stability Performance ◽

Nanosheet Arrays

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The hybrid nanostructure of MnCo2O4.5 nanoneedle/carbon aerogel for symmetric supercapacitors with high energy density

Nanoscale ◽

10.1039/c5nr04421a ◽

2015 ◽

Vol 7 (34) ◽

pp. 14401-14412 ◽

Cited By ~ 55

Author(s):

Pin Hao ◽

Zhenhuan Zhao ◽

Liyi Li ◽

Chia-Chi Tuan ◽

Haidong Li ◽

...

Keyword(s):

Energy Density ◽

Specific Capacitance ◽

Rate Capability ◽

Carbon Aerogel ◽

High Energy ◽

Cycling Stability ◽

High Energy Density ◽

Hybrid Nanostructure

A porous MnCo2O4.5 nanoneedle/carbon aerogel hybrid nanostructure was synthesized. The synergy of merits of the two kinds of supercapacitors endows the hybrid nanostructure with enhanced specific capacitance, rate capability, energy density and cycling stability.

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High-Performance Asymmetric Supercapacitors Based on the Ni1.5Co1.5S4@CNTs Nanocomposites

NANO ◽

10.1142/s1793292020501362 ◽

2020 ◽

Vol 15 (10) ◽

pp. 2050136

Author(s):

Xuan Zheng ◽

Xingxing He ◽

Jinlong Jiang ◽

Zhengfeng Jia ◽

Yu Li ◽

...

Keyword(s):

Energy Density ◽

Power Density ◽

High Performance ◽

Specific Capacity ◽

Negative Electrode ◽

High Energy ◽

Cycling Stability ◽

Power Delivery ◽

High Energy Density ◽

Practical Applications

In this paper, the Ni[Formula: see text]Co[Formula: see text]S4@CNTs nanocomposites containing different carbon nanotubes (CNT) content were prepared by a one-step hydrothermal method. More hydroxyl and carboxyl groups were introduced on the surface of CNTs by acidizing treatment to increase the dispersion of CNTs. The acid-treated CNTs can more fully compound with Ni[Formula: see text]Co[Formula: see text]S4 nanoparticles to form heterostructure. When the CNTs content is 10[Formula: see text]wt.%, the Ni[Formula: see text]Co[Formula: see text]S4@CNTs-10 nanocomposite exhibits the highest specific capacity of 210[Formula: see text]mAh[Formula: see text]g[Formula: see text] in KOH aqueous electrolytes at current density of 1[Formula: see text]A[Formula: see text]g[Formula: see text]. The superior performances of the Ni[Formula: see text]Co[Formula: see text]S4@CNTs-10 nanocomposite are attributed to the effective synergic effects of the high specific capacity of Ni[Formula: see text]Co[Formula: see text]S4 and the excellent conductivity of CNTs. An asymmetric supercapacitor (ASC) was assembled based on Ni[Formula: see text]Co[Formula: see text]S4@CNTs-10 positive electrode and activated carbon (AC) negative electrode, which delivers a high energy density of 61.2[Formula: see text]Wh[Formula: see text]kg[Formula: see text] at a power density of 800[Formula: see text]W[Formula: see text]kg[Formula: see text], and maintains 34.8[Formula: see text]Wh[Formula: see text]kg[Formula: see text] at a power density of 16079[Formula: see text]W[Formula: see text]kg[Formula: see text]. Also, the ASC device shows an excellent cycling stability with 91.49% capacity retention and above 94% Columbic efficiency after 10 000 cycles at 10[Formula: see text]A[Formula: see text]g[Formula: see text]. This aqueous asymmetric Ni[Formula: see text]Co[Formula: see text]S4@CNTs//AC supercapacitor is promising for practical applications due to its advantages such as high energy density, power delivery and cycling stability.

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β-NiMoO4 nanowire arrays grown on carbon cloth for 3D solid asymmetry supercapacitors

RSC Advances ◽

10.1039/c5ra14704b ◽

2015 ◽

Vol 5 (129) ◽

pp. 107098-107104 ◽

Cited By ~ 19

Author(s):

Chuanshen Wang ◽

Yi Xi ◽

Chenguo Hu ◽

Shuge Dai ◽

Mingjun Wang ◽

...

Keyword(s):

Energy Density ◽

Specific Capacitance ◽

Power Density ◽

High Energy ◽

Nanowire Arrays ◽

High Energy Density ◽

Carbon Cloth ◽

Maximum Power Density ◽

Capacity Retention ◽

3D Solid

A β-NiMoO4 NW supercapacitor lights one LED for 260 s and delivers a large specific capacitance (414.7 F g−1 at 0.25 A g−1), high energy density (36.86 W h kg−1), a maximum power density of 1100 W kg−1 and 65.96% capacity retention after 6000 cycles.

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α MnMoO4/graphene hybrid composite: high energy density supercapacitor electrode material

Dalton Transactions ◽

10.1039/c4dt00672k ◽

2014 ◽

Vol 43 (28) ◽

pp. 11067-11076 ◽

Cited By ~ 81

Author(s):

Debasis Ghosh ◽

Soumen Giri ◽

Md. Moniruzzaman ◽

Tanya Basu ◽

Manas Mandal ◽

...

Keyword(s):

Energy Density ◽

Power Density ◽

High Power ◽

Electrode Material ◽

Hybrid Composite ◽

High Energy ◽

High Energy Density ◽

High Power Density ◽

Supercapacitor Electrode

A hydrothermal procedure was employed to synthesize hexahedron shaped MnMoO4 wrapped with graphene exhibiting high energy density and high power density.

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Comparative Investigation of Non-halogenated Imidazolium and Phosphonium-based Surface-Active Ionic Liquids as Electrolyte for Supercapacitors

10.26434/chemrxiv.14459040.v1 ◽

2021 ◽

Author(s):

Preeti Jain ◽

Oleg N. Antzutkin

Keyword(s):

Ionic Liquids ◽

Energy Density ◽

Specific Capacitance ◽

Power Density ◽

High Energy ◽

High Energy Density ◽

Equivalent Series Resistance ◽

Imidazolium Cations ◽

Wide Range ◽

Surface Active

We report a comparative analysis of non-halogenated surface-active ionic liquids (SAILs), which consists of the surface-active anion, 2-ethylhexyl sulfate, and the phosphonium, and imidazolium cations i.e., tetrabutylphosphonium ([P4444]+), trihexyl(tetradecyl)phosphonium ([P66614]+), and 1-methyl-3-hexylimidazolium ([C6C1IM]+). We explored the thermal and electrochemical properties, i.e., degradation, melting and crystallization temperatures, and ionic conductivity of this new class of IL. These SAILs were tested as an electrolyte in a multi-walled carbon nanotubes (MWCNTs)-based supercapacitor at various temperatures from 253 to 373 K. The electrochemical performance of different SAILs by varying the cationic core as a function of temperature were compared, in the same MWCNT-based supercapacitor. We found that the supercapacitor cell with [C6C1IM][EHS] shown high specific capacitance (Celec in F g-1), a high energy density (E in Wh kg-1), and a high power density (P in kW kg-1) when compared to those for the other SAILs i.e. [P4444][EHS], [P66614][EHS], and [N8888][EHS] at all temperatures. The supercapacitor with an MWCNT-based electrode and [C6C1IM][EHS], [P4444][EHS], and [P66614][EHS] as an electrolyte showed a specific capacitance of 148, 90, and 47 F g-1 (at the scan rate of 2 mV s-1) with an energy density of 82, 50, and 26 Wh kg-1 (at 2 mV s-1) respectively, at 298 K. The temperature effect can be seen by the three to four-fold increase in the specific capacitance of the cell and the energy density values, i.e., 290, 198, and 114 F g-1 (at 2 mV s-1) and 161, 110, and 63 Wh kg-1 (at 2 mV s-1), respectively, at 373 K. This study reveals that these new SAILs specifically [C6C1IM][EHS] and [P4444][EHS] can potentially be used as electrolytes in the wide range of temperature. The solution resistance (Rs), charge transfer resistance (Rct), and equivalent series resistance (ESR) also decreased with an increase in temperature for all SAILs as electrolytes. These new SAILs can explicitly be used for high-temperature (wide range of temperature) electrochemical applications, such as efficient supercapacitors for high energy storage due to enhanced specific capacitance, energy, and power density at elevated temperatures.

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