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1.
Proton and lithium-ion conducting biodegradable solid polymer electrolytes were prepared using blends of poly(styrene sulphonic acid) (PSSA) and starch for supercapacitor applications. The ionic conductivities have been calculated using the bulk impedance obtained through impedance spectroscopy with varying blend ratio and plasticizer. Glycerol as plasticizer improved the film formation property, while lithium perchlorate (LiClO4) as dopant enhanced the conductivity. The maximum conductivity has been found to be 5.7?×?10?3?Scm?1 at room temperature for 80/20 (PSSA/starch) blend ratio. The dielectric studies showed relaxation peaks indicating proton and Li+ conduction in the plasticized polymer blend matrix and dielectric modulus also exhibited a long tail feature indicating good capacitance. Differential scanning calorimetry thermograms showed two peaks and decreased with varying blend ratio and plasticizer. A carbon?Ccarbon supercapacitor was fabricated using suitable electrolyte, and its electrochemical characteristics using cyclic voltammetry, AC impedance and galvanostatic charge?Cdischarge were studied. Supercapacitor showed a fairly good specific capacitance of 115?Fg?1 at 10?mV s?1.  相似文献   

2.
A symmetrical (p/p) supercapacitor has been fabricated by making use of activated carbon (AC)‐polyethylenedioxythiophene (PEDOT)‐composite electrodes for the first time. The composite electrodes have been prepared via electrochemical deposition of β‐napthalenesulphonate doped PEDOT onto AC electrodes. The characteristics of the electrodes and the fabricated supercapacitor have been investigated using cyclic voltammetry (CV) and AC impedance spectroscopy. The electrodes show a maximum specific capacitance of 158 Fg?1 at a scan rate of 10 mV s?1. This indicates that the in situ electro‐polymerization of ethylenedioxythiophene (EDOT) onto AC could improve the performance of carbon electrodes for use in supercapacitors. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008  相似文献   

3.
ABSTRACT

In this study, graphene oxide (GO) was chemically reacted with sodium borohydride (NaBH4) to form reduced graphene oxide (rGO). rGO, Montmorillonite nanoclay, and polyvinylcarbazole (PVK) were used to form a ternary nanocomposite via chemical reaction. These nanocomposite qualities were described via scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy-attenuated transmission reflectance (FTIR-ATR). In addition, these materials were used in supercapacitor device as an active material to test electrochemical performances via cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The rGO/nanoclay/PVK nanocomposite shows significantly improved specific capacitance (Csp = 168.64 Fg?1) compared to that of rGO (Csp = 63.26 Fg?1) at the scan rate of 10 mVs?1 by CV method. The enhanced capacitance results in high power density (P = 5522.6 Wkg?1) and energy density (E = 28.84 Whkg?1) capabilities of the rGO/nanoclay/PVK nanocomposite material. The addition of nanoclay and PVK increased the specific capacitance of rGO material due to a dopant effect for supercapacitor studies. Ragone plots were drawn to observe energy and power density of supercapacitor devices. The Csp of rGO/nanoclay/PVK nanocomposite has only 86.4% of initial capacitance for charge/discharge performances obtained by CV method for 5000 cycles.  相似文献   

4.
In the present work, we report high temperature performance of solid electrolyte supercapacitor based on activated carbon (AC) and phosphoric acid doped poly [2,5 benzimidazole] (ABPBI). Supercapacitors with varying concentrations of solid electrolyte in the electrode were fabricated and unit cells were analyzed over a wide temperature range of 27–120 °C. Supercapacitor with AC/ABPBI wt ratio 1.0:0.25 exhibited a specific capacitance of 197 F g?1 at room temperature. To the best of our knowledge, the value reported here is one of the highest for electric double layer supercapacitor with a solid electrolyte. The specific capacitance of supercapacitors having various compositions increased with temperature. The specific capacitance for AC/ABPBI wt ratio 1.0:0.25, capacitance increased to 248 F g?1 at 120 °C. The performance of supercapacitors was also analyzed by electrochemical impedance spectroscopy. The Nyquist plots at room temperature and 100 °C were studied by fitting them using Randles equivalent circuit. Supercapacitor with AC/ABPBI wt ratio 1.0:0.25 showed phase angle of 86.8° at low frequency which indicated excellent capacitive behavior at room temperature. The supercapacitor was found to have good stability during galvanostatic charge–discharge cycling even after repeated heating and cooling.  相似文献   

5.
Methylene blue (MB) redox mediator was introduced into polyvinyl alcohol/polyvinyl pyrrolidone (PVA/PVP) blend host to prepare a gel polymer electrolyte (PVA‐PVP‐H2SO4‐MB) for a quasi‐solid‐state supercapacitor. The electrochemical properties of the supercapacitor with the prepared gel polymer electrolyte were evaluated by cyclic voltammetry, galvanostatic charge–discharge, electrochemical impedance spectroscopy, and self‐discharge measurements. With the addition of MB mediator, the ionic conductivity of gel polymer electrolyte increased by 56% up to 36.3 mS·cm?1, and the series resistance reduced, because of the more efficient ionic conduction and higher charge transfer rate, respectively. The electrode specific capacitance of the supercapacitor with PVA‐PVP‐H2SO4‐MB electrolyte is 328 F·g?1, increasing by 164% compared to that of MB‐undoped system at the same current density of 1 A·g?1. Meanwhile, the energy density of the supercapacitor increases from 3.2 to 10.3 Wh·kg?1. The quasi‐solid‐state supercapacitor showed excellent cyclability over 2000 charge/discharge cycles. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39784.  相似文献   

6.
A polyaniline/titanium nitride (PANI/TiN) nanotube hybrid was prepared and used for an electrochemical supercapacitor application. Firstly, the well-aligned TiN nanotube array was prepared by anodization of titanium foil and subsequent nitridation through ammonia annealing. Then, PANI was deposited into TiN nanotube through the electrochemical polymerization process. The obtained PANI/TiN nanotube hybrid had an ordered porous structure. A high specific capacitance of 1,066 F g?1 was obtained at the charge–discharge current density of 1 A g?1 when only the mass of PANI was considered. The specific capacitance can even achieve 864 F g?1 at 10 A g?1 and still keep 93 % of the initial capacity after 200 cycles. An aqueous supercapacitor, consisting of two symmetric PANI/TiN nanotube hybrid electrodes and 1.0 M H2SO4 electrolyte solution, showed the specific capacitance of 194.8 F g?1, energy density of 9.74 Wh kg?1, and power density of 0.3 kW kg?1.  相似文献   

7.
The possibility of producing a biodegradable polymer electrolyte based on cellulose acetate (CA) with varied concentration of LiClO4 for use in supercapacitors has been investigated. The successful doping of the CA films has been analyzed by FTIR and DSC measurements of the LiClO4 doped CA films. The ionic conductivity of the films increased with increase in salt content and the maximum ionic conductivity obtained for the solid polymer electrolyte at room temperature was 4.9 × 10?3 Ω?1 for CA with 16% LiClO4. The biodegradation of the solid polymer electrolyte films have been tested by soil burial, degradation in activated sludge, and degradation in buffer medium methods. The extent of biodegradation in the films has been measured by AC Impedance spectroscopy and weight loss calculations. The study indicated sufficient biodegradability of the materials. A p/p polypyrrole supercapacitor has been fabricated and its electrochemical characteristics and performance have been studied. The supercapacitor showed a fairly good specific capacitance of 90 F g?1 and a time constant of 1 s. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

8.
Nanocomposite polymer electrolyte (NCPE) films of [75 wt % poly(ε‐caprolactone) : 25 wt % zinc triflate] + x wt % nanofiller Al2O3 (x = 1, 3, 5, 7) were prepared by solution cast technique. Such NCPE films were characterized using Fourier transform infrared and AC impedance spectroscopic techniques. Complexation of polymer with salt and nanofiller was revealed from FTIR analysis. On the other hand, an apparent increase in the number density of charge carriers upto 5 wt % loading of the nanofiller was also confirmed. Furthermore, AC impedance spectroscopic studies have shown that ionic conductivity increases with the addition of Al2O3 and reaches a maximum of 2.5 × 10?5 S cm?1 at room temperature for 5 wt % loading of nanofiller. The dielectric behavior of all the synthesized samples has also been analyzed and presented. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40524.  相似文献   

9.
Mesoporous carbon materials were prepared through atmospheric pressure impregnation at room temperature using attapulgite as hard template and maltose as carbon source. N2 absorption–desorption, X-ray diffraction, and transmission electron microscopy were used to determine the construction and morphology of the materials. The results showed that the prepared carbon materials possessed chain-layered structures whose surfaces were filled with ample nanoscale apertures. The materials also exhibited partial fasciculus with specific surface area and total pore volume of 628.6 mg?1 and 1.31 cm3 g?1, respectively. Constant current charge/discharge, cyclic voltammetry, and AC impedance tests were performed to evaluate the electrochemical performance of the materials. The constant current charge/discharge tests showed that the materials have excellent energy storage capacity. When the current density was 600 mA g?1, the specific capacitance value reached 171 F g?1. The materials showed quasi-rectangular features of typical cyclic voltammetry curve even at high scan rate (200 mV s?1), indicating that they possess excellent rate capacity. The AC impedance tests showed that the materials were typical porous electrode materials with combination resistance of 0.82 Ω. The specific capacitance of the materials reached 79 % after 1,000 constant current charge/discharge cycles, indicating that they have superior cyclic stability.  相似文献   

10.
Carbonization of milk-free coconut kernel pulp is carried out at low temperatures. The carbon samples are activated using KOH, and electrical double-layer capacitor (EDLC) properties are studied. Among the several samples prepared, activated carbon prepared at 600 °C has a large surface area (1,200 mg?1). There is a decrease in surface area with increasing temperature of preparation. Cyclic voltammetry and galvanostatic charge–discharge studies suggest that activated carbons derived from coconut kernel pulp are appropriate materials for EDLC studies in acidic, alkaline, and non-aqueous electrolytes. Specific capacitance of 173 F g?1 is obtained in 1 M H2SO4 electrolyte for the activated carbon prepared at 600 °C. The supercapacitor properties of activated carbon sample prepared at 600 °C are superior to the samples prepared at higher temperatures.  相似文献   

11.
Polyaniline salts containing sulfuric acid and cetyltrimethylammonium sulfate dopants were prepared by aqueous (PANI-Aq), emulsion (PANI-Em), and interfacial (PANI-In) polymerization pathways using cetyltrimethylammonium peroxodisulfate as an oxidative template. Formation of polyaniline was confirmed from infrared and X-ray diffraction spectral results. Value of conductivity (15 S cm?1) of the polyaniline salt prepared by emulsion polymerization pathway was higher with that of the conventional polyaniline salt. PANI-Aq, PANI-Em, and PANI-In showed layered, flower petals, and nanorod and flower petals morphologies, respectively. These polyaniline salts were used as electrode in supercapacitor. Specific capacitance of PANI-Em, PANI-Aq, and PANI-In were 520, 484, and 474 F g?1, which were higher than the conventional PANI-H2SO4 salt (390). Energy density was 26, 24.2, and 23.6 Wh kg?1, respectively at a power density of 120 W kg?1. After 3000 charge-discharge cycles, retention in the specific capacitance values of polyaniline salts was 86% (PANI-Em), 85.4% (PANI-Aq) and 76.1% (PANI-In).  相似文献   

12.

CoZn layered double hydroxide (LDH) or Co(OH)2 pseudocapacitive material has been prepared on the current collector of carbon fiber paper (CFP) using an eco-friendly one-step electrodeposition. Benefiting from its unique structural feature, the binder-free CoZn LDH/CFP electrode material realizes high specific capacitance of 1156 Fg?1 at a current density of 1 Ag?1 and excellent rate capability of 80% retention with 16 fold current density increment, which is much better than that of Co(OH)2 (617 Fg?1, 65%). Notably, the CoZn LDH/CFP can retain an outstanding electrochemical stability with a capacitance degradation of only 6% after 6000 charge–discharge cycles at 32 Ag?1. Moreover, an asymmetric supercapacitor (ASC) using CoZn LDH/CFP as a positive electrode and AC/CFP as a negative electrode has been assembled. The ASC exhibits a superior energy density of 30.0 Whkg?1 at a power density of 800 Wkg?1 with a specific capacitance up to 84.4 Fg?1 and a potential window wide to 1.6 V. These encouraging results indicate that CoZn LDH/CFP composite material has a great potential for next-generation energy conversion/storage devices.

  相似文献   

13.
Spinel Li4Mn5O12 was prepared by a sol–gel method. The manganese oxide and activated carbon composite (MnO2-AC) were prepared by a method in which KMnO4 was reduced by activated carbon (AC). The products were characterized by XRD and FTIR. The hybrid supercapacitor was fabricated with Li4Mn5O12 and MnO2-AC, which were used as materials of the two electrodes. The pseudocapacitance performance of the Li4Mn5O12/MnO2-AC hybrid supercapacitor was studied in various aqueous electrolytes. Electrochemical properties of the Li4Mn5O12/MnO2-AC hybrid supercapacitor were studied by using cyclic voltammetry, electrochemical impedance measurement, and galvanostatic charge/discharge tests. The results show that the hybrid supercapacitor has electrochemical capacitance performance. The charge/discharge test showed that the specific capacitance of 51.3 F g−1 was obtained within potential range of 0–1.3 V at a charge/discharge current density of 100 mA g−1 in 1 mol L−1 Li2SO4 solution. The charge/discharge mechanism of Li4Mn5O12 and MnO2-AC was discussed.  相似文献   

14.
《Ceramics International》2021,47(19):27132-27141
Reinforcing polyoxomolybdates (POMs) into the activated carbon (AC) template engenders a nanohybrid electrode material for high-performance supercapacitor applications. Herein, a first-time novel integration of two polyoxometalates ([PVMo11O40]4-, [PV2Mo10O40]5-) with AC has been demonstrated, and their structural and electrochemical performances were analyzed. AC-VMo11 composite displayed an enhanced capacitance of 450 Fg-1 with an improved energy density of 59.7 Whkg-1. Furthermore, the symmetric supercapacitor cell for AC-VMo11 and AC-V2Mo10 showed high cell capacitances of 38.8 and 20.01 mF, respectively, alongside 99.99% capacitance retention of over 5000 cycles. In addition, the influence of ionic liquid as an electrolyte on AC-V2Mo10 based supercapacitor cell was investigated in tetrabutylammonium bromide (TBAB) electrolyte solution.  相似文献   

15.
The effect of halide ion concentration on the capacitor performance was considered during this study. Iodide anion has been selected as the most profitable halide taking into account its electrochemical properties and environmental impact. Several concentrations of NaI were tested (from 0.25 to 5 mol L?1 aqueous solutions) using as electrodes two commercial activated carbons and one KOH-activated carbon. Detailed electrochemical investigation by galvanostatic charging/discharging, cyclic voltammetry, and impedance spectroscopy confirmed the significant impact of iodide concentration on the supercapacitor behavior. The higher concentration of iodide affected especially the performance of positive electrode; increase of iodide concentration changed the potential range of positive electrode and its capacitance increased from 119 F g?1 for 0.25 mol L?1 NaI to 475 F g?1 for 2 mol L?1 NaI solution. The electrode capacitance measured in two-electrode system at current density of 2 A g?1 ranged from 198 F g?1 for 0.25 mol L?1 NaI to 272 F g?1 for 2 mol L?1 NaI solution (capacitance expressed as average of the positive and negative electrode capacitances). It has been proved that 2 mol L?1 alkali metal iodide solution is an optimal electrolyte for the capacitor based on KOH-activated carbon. High capacitance values and perfect stability (100 % retention) of such systems have been observed during long-term galvanostatic charging/discharging (15,000 cycles). In addition, satisfactory floating tests at extended voltage range (1.2 V) were performed.  相似文献   

16.
Nickel molybdate (NiMoO4) nanoparticles (NPs) were synthesized by a simplistic one-pot microwave combustion method using urea as the fuel. The produced NPs have been examined by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) analysis, scanning electron microscope (SEM), energy dispersive X-ray (EDX), high-resolution transmission electron microscopy (HR-TEM) analysis. Further, optical and electronic properties were determined by UV-Visible and Photoluminescence (PL) analysis, respectively. The magnetic performance of the NiMoO4 NPs was investigated by vibrating sample magnetometer (VSM) and the surface chemical composition was identified by X-ray photoelectron spectroscopy (XPS). The electrochemical activities of the NiMoO4 NPs were studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge (GCD) analysis. From the results, the CV curves indicated the occurrence of redox couples and besides with the EIS data (Nyquist plot), confirmed the supercapacitor nature of the synthesized NiMoO4. The prepared NiMoO4 exhibits a high specific capacitance and rateability. This electrode grants a high specific capacitance of 450?F?g?1 at 2?mA?cm?2 and the well permanency with a cycling proficiency of 94% after 1000 cycles. These results clearly showed that the synthesized NiMoO4 NPs have potential application for the forthcoming flexible and lightweight energy storage.  相似文献   

17.
Electrospun poly[(vinylidene fluoride)‐co ‐hexafluoropropylene]/silica (PVdF‐HFP/SiO2) nanocomposite polymer membranes (esCPMs) were prepared by incorporating different weight percentages of SiO2 nanoparticles onto electrospun PVdF‐HFP by electrospinning technique. The surface morphology of electrospun PVdF‐HFP nanocomposite membranes was characterized by scanning electron microscopy. The effect of SiO2 nanoparticles incorporation onto electrospun PVdF‐HFP polymer membranes (esPMs) has been studied by XRD, DSC, TGA, and tensile analysis. The electrospun PVdF‐HFP/SiO2 based nanocomposite membrane electrolytes (esCPMEs) were prepared by soaking the corresponding esCPMs into 1 M LiPF6 in EC:DMC (1:1 vol/vol %). The ionic conductivity of the esCPMEs was studied by AC‐impedance studies and it was found that the incorporation of SiO2 nanoparticles into PVdF‐HFP membrane has improved the ionic conductivity from 1.320 × 10?3 S cm?1 to 2.259 × 10?3 S cm?1. The electrochemical stability of the esCPME was studied by linear sweep voltammetry studies and it was found to be 2.87 V. Finally, a prototype LiCo0.2Mn1.8O4//C Li‐ion capacitor (LIC) cell was fabricated with esCPME, which delivered a discharge capacitance of 128 F g?1 at the current density of 1 A g?1 and retained 86% of its discharge capacitance even after 10,000 cycles. These results demonstrated that the esCPMEs could be used as promising polymer membrane electrolyte for LICs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45177.  相似文献   

18.
The exploration of high performance supercapacitors has received emerging the worldwide research interests in satisfying the gradually increased energy consumption. In this paper, we adopt a facile hydrothermal strategy to synthesize ternary FeCo2O4 directly on nickel foam. A series of structure such as nanowires, nanoflake@nanowire hetero-structure and hierarchical nanospheres have been achieved via modulating the synthetic time. The morphology and structure of the as-prepared samples are characterized by using scanning electron microscopy and X-ray diffraction spectroscopy. The relationship between the detail processing parameters and electrochemical performance are also revealed by cyclic voltammetry, galvanostatic charge-discharge measurements, cycle stability tests and electrochemical impedance spectroscopy. Notably, the as-prepared nanoflake@nanowire hetero-structure exhibits a high specific capacitance of about 969 F g?1 at 2 A g?1 in alkaline aqueous solution and a remarkable cycling stability (91% capacity retention after 2000 cycles). The excellent supercapacitors performance of nanoflake@nanowire hetero-structure can be attributed to the high conductivity, large active area as well as robust architectures that derive from structural synergetic effects. Furthermore, a symmetric all solid-state supercapacitor has been fabricated by using nanoflake@nanowire hetero-structure as both the anode and cathode electrodes. The as-fabricated supercapacitor delivers excellent electrochemical performance. It's anticipated that FeCo2O4 would be a promising material for electrochemical energy storage applications.  相似文献   

19.
A comb‐like polyether, poly(3‐2‐[2‐(2‐methoxyethoxy)ethoxy]ethoxymethyl‐3′‐methyloxetane) (PMEOX), was reacted with hexamethylene diisocyanate and extended with butanediol in a one‐pot procedure to give novel thermoplastic elastomeric poly(ether urethane)s (TPEUs). The corresponding hybrid solid polymer electrolytes were fabricated through doping a mixture of TPEU and poly(vinylidene fluoride) with three kinds of lithium salts, LiClO4, LiBF4 and lithium trifluoromethanesulfonimide (LiTFSI), and were characterized using differential scanning calorimetry, thermogravimetric analysis and Fourier transform infrared spectroscopy. The ionic conductivity of the resulting polymer electrolytes was then assessed by means of AC impedance measurements, which reached 2.1 × 10?4 S cm?1 at 30 °C and 1.7 × 10?3 S cm?1 at 80 °C when LiTFSI was added at a ratio of O:Li = 20. These values can be further increased to 3.5 × 10?4 S cm?1 at 30 °C and 2.2 × 10?3 S cm?1 at 80 °C by introducing nanosized SiO2 particles into the polymer electrolytes. Copyright © 2006 Society of Chemical Industry  相似文献   

20.
Herein, [As2IIIAsVMo8VIV4IVO40]2[CuICu2II(pz)4]2·9H2O/polyaniline/reduced graphene oxide (pz = pyrazine, abbreviated to As3Mo8V4/PANi/rGO) composite is first assembled, characterized and systematically explored for its supercapacitor performance. As3Mo8V4/PANi/rGO composite shows a exceptional specific capacitance (2351 F g?1 at 1 A g?1) and outstanding cyclic stability (96.9% after 5000 cycles). The symmetric supercapacitor exhibits high specific capacitance of 1295 F g?1 at 1 A g?1 and excellent energy density of 88.1 Wh kg-1 at power density of 349.6 W kg-1, while maintaining a notable capacitance retention of 85.7% after 5000 cycles at 2 A g-1. The above results confirm the potential application of As3Mo8V4/PANi/rGO composite in energy storage devices.  相似文献   

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