Ionophobic nanopore enhancing capacitance and charging dynamics in supercapacitor with ionic liquids

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

10.26434/chemrxiv.14459040 ◽

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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Full capacitance potential of SWCNT electrode in ionic liquids at 4 V

Journal of Materials Chemistry A ◽

10.1039/c4ta04773g ◽

2014 ◽

Vol 2 (46) ◽

pp. 19897-19902 ◽

Cited By ~ 13

Author(s):

Yuntao Yu ◽

Chaojie Cui ◽

Weizhong Qian ◽

Fei Wei

Keyword(s):

Ionic Liquids ◽

Energy Density ◽

Power Density ◽

Density Range

SWCNT electrode exhibited a capacitance of 16 μF cm−2 and an energy density of 107 W h kg−1 in a wide power density range at 4 V.

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Enhancing 5 V capacitor performance by adding single walled carbon nanotubes into an ionic liquid electrolyte

Journal of Materials Chemistry A ◽

10.1039/c5ta04167h ◽

2015 ◽

Vol 3 (31) ◽

pp. 15858-15862 ◽

Cited By ~ 9

Author(s):

Chuiyan Kong ◽

Weizhong Qian ◽

Chao Zheng ◽

Wei Fei

Keyword(s):

Carbon Nanotubes ◽

Ionic Liquid ◽

Ionic Liquids ◽

Energy Density ◽

Power Density ◽

Single Walled Carbon Nanotubes ◽

Liquid Electrolyte ◽

Ionic Liquid Electrolyte ◽

Single Walled Carbon ◽

Walled Carbon Nanotubes

A nanofluid electrolyte of single walled carbon nanotubes and ionic liquids enhances the energy density, power density and cycling stability of nanotube electrodes at 5 V.

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Multi-Scale Simulation of High Energy Density Ionic Liquids

10.21236/ada472626 ◽

2007 ◽

Author(s):

Gregory A. Voth

Keyword(s):

Ionic Liquids ◽

Energy Density ◽

High Energy ◽

High Energy Density ◽

Multi Scale

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

Nanoscale Research Letters ◽

10.1186/s11671-021-03545-8 ◽

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.

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Novel Lithium-Ion Capacitor Based on a NiO-rGO Composite

Materials ◽

10.3390/ma14133586 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3586

Author(s):

Qi An ◽

Xingru Zhao ◽

Shuangfu Suo ◽

Yuzhu Bai

Keyword(s):

Energy Storage ◽

Energy Density ◽

Power Density ◽

High Power ◽

Specific Capacity ◽

Lithium Ion ◽

High Energy ◽

Cycle Life ◽

High Energy Density ◽

Lithium Ion Capacitor

Lithium-ion capacitors (LICs) have been widely explored for energy storage. Nevertheless, achieving good energy density, satisfactory power density, and stable cycle life is still challenging. For this study, we fabricated a novel LIC with a NiO-rGO composite as a negative material and commercial activated carbon (AC) as a positive material for energy storage. The NiO-rGO//AC system utilizes NiO nanoparticles uniformly distributed in rGO to achieve a high specific capacity (with a current density of 0.5 A g−1 and a charge capacity of 945.8 mA h g−1) and uses AC to provide a large specific surface area and adjustable pore structure, thereby achieving excellent electrochemical performance. In detail, the NiO-rGO//AC system (with a mass ratio of 1:3) can achieve a high energy density (98.15 W h kg−1), a high power density (10.94 kW kg−1), and a long cycle life (with 72.1% capacity retention after 10,000 cycles). This study outlines a new option for the manufacture of LIC devices that feature both high energy and high power densities.

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The influences of operating conditions and design configurations on the performance of symmetric electrochemical capacitors

Physical Chemistry Chemical Physics ◽

10.1039/c6cp06214h ◽

2016 ◽

Vol 18 (41) ◽

pp. 28626-28647 ◽

Cited By ~ 5

Author(s):

Innocent S. Ike ◽

Iakovos Sigalas ◽

Sunny E. Iyuke

Keyword(s):

Energy Density ◽

Power Density ◽

Electrochemical Capacitors ◽

Electrochemical Capacitor ◽

Operating Conditions ◽

Modelling And Simulation ◽

Charging Current ◽

Current Densities

The influence of different charging current densities, charging times and several structural designs on symmetric electrochemical capacitor (EC) performance, including capacitance, energy density and power density, has been investigated via modelling and simulation.

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