A Promising Polymer Blend Electrolytes Based on Chitosan: Methyl Cellulose for EDLC Application with High Specific Capacitance and Energy Density

In the present work, promising proton conducting solid polymer blend electrolytes (SPBEs) composed of chitosan (CS) and methylcellulose (MC) were prepared for electrochemical double-layer capacitor (EDLC) application with a high specific capacitance and energy density. The change in intensity and the broad nature of the XRD pattern of doped samples compared to pure CS:MC system evidencedthe amorphous character of the electrolyte samples. The morphology of the samples in FESEM images supported the amorphous behavior of the solid electrolyte films. The results of impedance and Bode plotindicate that the bulk resistance decreasedwith increasing salt concentration. The highest DC conductivity was found to be 2.81 × 10−3 S/cm. The electrical equivalent circuit (EEC) model was conducted for selected samples to explain the complete picture of the electrical properties.The performance of EDLC cells was examined at room temperature by electrochemical techniques, such as impedance spectroscopy, cyclic voltammetry (CV) and constant current charge–discharge techniques. It was found that the studied samples exhibit a very good performance as electrolyte for EDLC applications. Ions were found to be the dominant charge carriers in the polymer electrolyte. The ion transference number (tion) was found to be 0.84 while 0.16 for electron transference number (tel). Through investigation of linear sweep voltammetry (LSV), the CS:MC:NH4SCN system was found to be electrochemically stable up to 1.8 V. The CV plot revealed no redox peak, indicating the occurrence of charge double-layer at the surface of activated carbon electrodes. Specific capacitance (Cspe) for the fabricated EDLC was calculated using CV plot and charge–discharge analyses. It was found to be 66.3 F g−1 and 69.9 F g−1 (at thefirst cycle), respectively. Equivalent series resistance (Resr) of the EDLC was also identified, ranging from 50.0 to 150.0 Ω. Finally, energy density (Ed) was stabilized to anaverage of 8.63 Wh kg−1 from the 10th cycle to the 100th cycle. The first cycle obtained power density (Pd) of 1666.6 W kg−1 and then itdropped to 747.0 W kg−1 at the 50th cycle and continued to drop to 555.5 W kg−1 as the EDLC completed 100 cycles.

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High Proton Conducting Polymer Blend Electrolytes Based on Chitosan:Dextran with Constant Specific Capacitance and Energy Density

Biomolecules ◽

10.3390/biom9070267 ◽

2019 ◽

Vol 9 (7) ◽

pp. 267 ◽

Cited By ~ 22

Author(s):

Shujahadeen B. Aziz ◽

M. H. Hamsan ◽

Wrya O. Karim ◽

M. F. Z. Kadir ◽

M. A. Brza ◽

...

Keyword(s):

Cyclic Voltammetry ◽

Energy Density ◽

Specific Capacitance ◽

Polymer Blend ◽

Linear Sweep Voltammetry ◽

Transference Number ◽

Ammonium Fluoride ◽

Constant Current ◽

Discharge Process ◽

Charge Discharge

Polymer blend electrolytes based on chitosan: dextran (CS:Dext) incorporated with various amounts of ammonium fluoride (NH4F) with constant specific capacitance (12.4 F/g) and energy density over 100 cycles were prepared using a solution cast technique. The blend electrolyte samples exhibit broader amorphous humps in X-ray diffraction (XRD) spectra compared to pure CS:Dext film. The Fourier transform infrared (FTIR) study indicates the complex formation of the added ammonium salt with the polymer blend functional groups through the shifting and decrease in the intensity of FTIR bands. The impedance plots were used to determine the conductivity of the samples. The field emission scanning electron microscopy (FESEM) images support the conductivity behavior of the samples. The impedance plots were applied in the determination of the conductivity of the samples in which the relatively highest conductivity was gained to be 1 × 10−3 S/cm. The transference number measurement (TNM) of the conducting electrolyte was 0.88, which portrays the dominancy of ion in the conduction process. Linear sweep voltammetry (LSV) verified the chemical stability and showed it to be 1.7 V and an effective electrical double layer capacitor (EDLC) that is applicable in electrochemical devices. The performance of the EDLC cell was examined using both cyclic voltammetry and constant current charge–discharge techniques at ambient temperature. The semi-rectangular shape of the cyclic voltammetry (CV) plot and no redox peak was observed. The charge-discharge process of the fabricated EDLC is durable over 100 cycles with an equivalent circuit resistance and power density of 194.5 Ω and 428 W/kg, respectively. Two main outcomes, the specific capacitance and energy densities of 12.4 Farad/g and 1.4 Wh/kg, respectively, are almost constant over 100 cycles.

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Characteristics of Glycerolized Chitosan: NH4NO3-Based Polymer Electrolyte for Energy Storage Devices with Extremely High Specific Capacitance and Energy Density Over 1000 Cycles

Polymers ◽

10.3390/polym12112718 ◽

2020 ◽

Vol 12 (11) ◽

pp. 2718

Author(s):

Shujahadeen B. Aziz ◽

M. A. Brza ◽

Iver Brevik ◽

M. H. Hamsan ◽

Rebar T. Abdulwahid ◽

...

Keyword(s):

Energy Storage ◽

Energy Density ◽

Polymer Electrolyte ◽

Specific Capacitance ◽

Electrochemical Techniques ◽

High Specific Capacitance ◽

Transference Number ◽

Energy Storage Devices ◽

Storage Devices ◽

The Impact

In this work, plasticized polymer electrolyte films consisting of chitosan, ammonium nitrate (NH4NO3) and glycerol for utilization in energy storage devices was presented. Various microscopic, spectroscopic and electrochemical techniques were used to characterize the concerned electrolyte and the electrical double-layer capacitor (EDLC) assembly. The nature of complexation between the polymer electrolyte components was examined via X-ray diffraction analysis. In the morphological study, field emission scanning electron microscopy (FESEM) was used to investigate the impact of glycerol as a plasticizer on the morphology of films. The polymer electrolyte (conducting membrane) was found to have a conductivity of 3.21 × 10−3 S/cm. It is indicated that the number density (n), mobility (μ) and diffusion coefficient (D) of ions are increased with the glycerol amount. The mechanism of charge storing was clarified, which implies a non-Faradaic process. The voltage window of the polymer electrolyte is 2.32 V. It was proved that the ion is responsible for charge-carrying via measuring the transference number (TNM). It was also determined that the internal resistance of the EDLC assembly lay between 39 and 50 Ω. The parameters associated with the EDLC assembly are of great importance and the specific capacitance (Cspe) was determined to be almost constant over 1 to 1000 cycles with an average of 124 F/g. Other decisive parameters were found: energy density (18 Wh/kg) and power density (2700 W/kg).

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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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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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Effects of Deposition Temperatures on the Nanoflakes Co(OH)2 Porous Films for Supercapacitors

Materials Science Forum ◽

10.4028/www.scientific.net/msf.694.214 ◽

2011 ◽

Vol 694 ◽

pp. 214-218

Author(s):

Zhan Jun Yu ◽

Bin Bin Wang ◽

Rong Bao Liao ◽

Yu Min Cui

Keyword(s):

Specific Capacitance ◽

Electrochemical Impedance ◽

Electrochemical Techniques ◽

High Specific Capacitance ◽

Electrochemical Technique ◽

Porous Films ◽

Discharge Current Density ◽

A Charge ◽

Maximum Specific Capacitance ◽

Charge Discharge

Nanoflakes Co(OH)2 porous films were successfully synthesized by a facile electrochemical technique. The morphology was characterized by field emission scanning electron microscopy (FESEM). Electrochemical techniques such as cyclic voltammetry (CV), galvanostaitc charge/discharge and electrochemical impedance spectroscopy were used to study the effects of deposition temperatures on the capacitance of the films. The results exhibited that the Co(OH)2 films single electrode had high specific capacitance in KOH electrolyte. A maximum specific capacitance of 2780 F/g could be achieved for the Co(OH)2 film deposited at 50°C in 2 M aqueous KOH with 0 to 0.4V potential at a charge-discharge current density of 4 mA/cm2. Therefore, the obtained nanoflakes Co(OH)2 porous films can be a potential application electrode material for supercapacitors.

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A Study of Methylcellulose Based Polymer Electrolyte Impregnated with Potassium Ion Conducting Carrier: Impedance, EEC Modeling, FTIR, Dielectric, and Device Characteristics

Materials ◽

10.3390/ma14174859 ◽

2021 ◽

Vol 14 (17) ◽

pp. 4859

Author(s):

Muaffaq M. Nofal ◽

Jihad M. Hadi ◽

Shujahadeen B. Aziz ◽

Mohamad A. Brza ◽

Ahmad S. F. M. Asnawi ◽

...

Keyword(s):

Specific Capacitance ◽

Double Layer ◽

Electrochemical Impedance ◽

Low Frequency ◽

Linear Sweep Voltammetry ◽

High Specific Capacitance ◽

Transference Number ◽

Sweep Rate ◽

Electrochemical Characteristics ◽

Ion Conducting

In this research, a biopolymer-based electrolyte system involving methylcellulose (MC) as a host polymeric material and potassium iodide (KI) salt as the ionic source was prepared by solution cast technique. The electrolyte with the highest conductivity was used for device application of electrochemical double-layer capacitor (EDLC) with high specific capacitance. The electrical, structural, and electrochemical characteristics of the electrolyte systems were investigated using various techniques. According to electrochemical impedance spectroscopy (EIS), the bulk resistance (Rb) decreased from 3.3 × 105 to 8 × 102 Ω with the increase of salt concentration from 10 wt % to 40 wt % and the ionic conductivity was found to be 1.93 ×10−5 S/cm. The dielectric analysis further verified the conductivity trends. Low-frequency regions showed high dielectric constant, ε′ and loss, ε″ values. The polymer-salt complexation between (MC) and (KI) was shown through a Fourier transformed infrared spectroscopy (FTIR) studies. The analysis of transference number measurement (TNM) supported ions were predominantly responsible for the transport process in the MC-KI electrolyte. The highest conducting sample was observed to be electrochemically constant as the potential was swept linearly up to 1.8 V using linear sweep voltammetry (LSV). The cyclic voltammetry (CV) profile reveals the absence of a redox peak, indicating the presence of a charge double-layer between the surface of activated carbon electrodes and electrolytes. The maximum specific capacitance, Cs value was obtained as 118.4 F/g at the sweep rate of 10 mV/s.

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