High-efficiency and lightweight electrodes are advantageous for acquiring high-energy density and flexible supercapattery. Herein, binder-free electrodes were fabricated by growing directly nickel ...sulfide (NiS) nanoflakes and coral-like nickel sulfide-copper sulfide (NiCuS) on nickel foam using hydrothermal method. Structural studies show that both electrodes are composed of multiphases crystalline structure. Morphological studies reveal that the incorporation of Cu ion has greatly influenced the morphology of NiS, i.e., from nanoflake arrays to coral-like structure (built by interconnected nanotubular). The electrochemical studies demonstrate that the presence of Cu in NiCuS significantly improved the specific capacity of NiS from 382 to 688 C/g at 10 A/g. Moreover, the rate capability of NiS is enhanced from 69 to 78% capacity retention. The origin of the enhancement in performance shown by NiCuS as compared with NiS is due to the enhancement in electroactive sites and reduced internal resistance contributed from the presence of different valence states. In order to access the real-time performance of NiCuS electrode, supercapattery was assembled. The device exhibits the energy density of 23 Wh/kg at 388 W/kg and degraded only 16% of its initial capacity after 5000 cycles.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this study, we demonstrated the influence of cobalt oxalate hydrate (CoC
2
O
4
.nH
2
O), the working electrode for supercapattery. A binder-free electrode composed of CoC
2
O
4
.nH
2
O synthesized ...directly on the nickel foam via hydrothermal method. L-ascorbic acid (LAA) was used as a morphology-directing green-reducing agent and as an oxalate source. The structural characterization was rationalized by studying the effect of reaction time on the growth of CoC
2
O
4
.nH
2
O. The electrodes prepared using 8, 10, 12, and 14 drops of potassium hydroxide (KOH) were heated for 6 h. The optimized sample was then selected and heated for 24 h. The crystallinity of the electrode increased with increasing hydrothermal reaction time. In electrochemical measurements, the effects of heating time and different drops of KOH on the formation of different cobalt oxalate hydrates were discussed in detail. The electrode prepared using 10 drops of KOH followed by 6 h of heating process exhibited excellent specific capacity/capacitance even at 10 A g
−1
(575 C g
−1
/1203.64 F g
−1
) with maximum energy density and power density of 59 Wh kg
−1
and 2389 W kg
−1
, respectively. The supercapattery using CoC (10) exhibited splendid capacity retention of 102% over 10,000 cycles confirming its suitability as a battery-type electrode for supercapattery.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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•Co(OH)2 was inlaid on Co3(PO4)3 to form an outstanding battery-grade material.•The energy density of Co3(PO4)3-Co(OH)2 was almost double of pristine Co3(PO4)3.•Metal precursor ...concentration for Co(OH)2 formation affects overall performance.
Supercapattery is one of the emerging alternative energy storage technologies and numerous recent studies have been done in search of good electrode material for its application. Cobalt phosphate (Co3(PO4)2) is a promising candidate due to its abundance, low cost, valence states variation, and good faradaic property. However, cobalt phosphates have limited surface area, affecting its electrochemical performance. To overcome that, herein Co3(PO4)2 was synthesized via sonochemical method and calcined at various temperatures to obtain the best calcination temperature followed by coating of cobalt hydroxide (Co(OH)2) layer. The synthesis of Co3(PO4)2 and coating of Co(OH)2 over cobalt phosphate was observed through X-ray diffraction analysis (XRD) and the morphology of the synthesized nanostructures was observed using Field emission scanning electron microscopy (FESEM). Cyclic voltammetry, galvanostatic charge discharge, and electrochemical impedance spectroscopy analyses were carried out. The results showed calcination temperature of 200 °C followed by coating of Co(OH)2 using 2 mM metal precursor as the optimized sample. This sample exhibited the fascinating electrochemical performance of specific capacitance (2111.83F g−1 at 1 A g−1), energy density (72.51 Wh kg−1 at 1 A g−1), and power density (2357 W kg−1 at 10 A g−1) and fabricated supercapattery demonstrated outstanding cyclic stability up to 84 % over 15,000 charge/discharge cycles.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Most of commercialized electrical double layer capacitors (EDLCs) with liquid electrolyte are bulky, non-flexible and unsafe which require solid polymer electrolyte (SPE) as the replacement. Herein, ...SPE containing tetraglyme as the ionic conductivity booster was prepared in which polyvinyl alcohol (PVA), magnesium trifluoromethane sulfonate (Mg (Tf)
2
) and tetraglyme (TEDGME) have been utilized as the host polymer, salt and additive, respectively. After the addition of TEDGME, the SPE exhibited a significant boost in ionic conductivity from 1.43 × 10
−9
to 3.10 × 10
−5
S cm
−1
. This is attributed to the presence of multiple ether oxygen atom functional group from TEDGME that provides more charge carriers. Fourier transform infrared spectroscopy authenticates the formation of complex within the SPE systems which indicates the formation of good interaction between the host polymer and the salts. X-ray diffraction analysis demonstrates the reduction in crystallinity of the SPE after the addition of TEDGME which is beneficial for the ion diffusion. The maximum specific capacitance achieved by the EDLC employing the SPE incorporated with TEDGME is 6.34 F/g at 0.04 A/g, with the rate capability of 74.1%.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
1-Methyl-3-propylimidazolium iodide (MPII) ionic liquid incorporated gel polymer electrolyte (GPE) has successfully enhanced the efficiency of a dye-sensitized solar cell (DSSC). A series of gel ...polymer electrolytes containing different amounts of MPII were prepared and characterized. A maximum ionic conductivity of 3.99 mS cm
−1
was obtained in a GPE containing 10 wt% MPII, which was accompanied by the lowest activation energy. The results from dielectric studies showed typical behaviour for both ɛ’ and ɛ” in which their values decreased with increasing frequency but increased proportionately with temperature. From the results of FESEM, the morphologies of the GPE became slightly rougher after the addition of MPII. Dye-sensitized solar cells were fabricated and characterized using electrochemical impedance spectroscopy (EIS) and photovoltaic studies. DSSC with the best performance (4.35% of efficiency, 9.97 mA cm
−2
of
J
SC
, 0.67 V of
V
OC
, and 65.39% of fill factor) was assembled using the GPE with 10 wt% of MPII.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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•Co3O4 nanograin-decorated rGO composite was fabricated via hydrothermal route.•rGO-Co3O4 nanograin composite was used for modification of electrode.•rGO-Co3O4 nanograins showed ...excellent catalytic performance towards dopamine detection.•rGO-Co3O4 nanocomposite selectively detected dopamine in the presence of interfering species.
A sensitive and selective detection of dopamine (DA) by a sensor based on cobalt oxide (Co3O4) nanograin-decorated reduced graphene oxide (rGO) composite modified glassy carbon electrode (GCE) is reported. The rGO-Co3O4 nanograin composites are synthesized by a facile hydrothermal route and optimized by varying the contents of rGO (5.7, 7.4, 9.1 and 10.7wt%, denoted as C1, C2, C3 and C4 respectively). The crystallinity of the composite is examined by X-ray diffraction (XRD). Raman spectrum revealed the successful reduction of graphene oxide (GO) into rGO. The surface morphology through field emission scanning electron microscopy (FESEM) revealed that the granular-shaped Co3O4 are decorated on rGO matrix with an average particle size of∼35nm. For electrochemical oxidation of DA, glassy carbon electrode (GCE) is modified with nanocomposites. Cyclic voltammetric results show that C3 modified GCE exhibit enhanced electrocatalytic performance in terms of oxidation potential and peak current in comparison to those of bare GCE, Co3O4 nanograins, C1, C2 and C4 modified GCE. The choronoamperometric studies indicate that C3 modified GCE exhibit a low detection limit of (S/N=3) 0.277μM in the linear range of 1–30μM. In addition, C3 demonstrates good selectivity towards the detection of DA in the presence of a 100-fold higher concentration of ascorbic acid, glucose and uric acid as the interfering species. The electrochemical sensing studies suggest that 3D rGO-Co3O4 nanograins endow excellent catalytic activity, high selectivity and sensitivity towards DA.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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•Nickel oxide with different particle sizes are developed by a facile process.•The smaller particle size of 6nm with face centered cubic structure was observed.•CV and EIS study shows ...the pseudocapacitive behavior of NiO nanostructures.•NiO with smaller particle size exhibited enhanced specific capacitance.
In this work, we demonstrate the influence of nickel oxides with divergent particle sizes as the working electrodes for supercapacitor application. The nanostructured nickel oxide (NiO) is synthesized via facile sonochemical method, followed by calcination process. The crystallinity and surface purity of prepared samples are clearly examined by X-ray diffraction and Raman analysis. NiO crystallinity is significantly increased with increasing calcination temperatures. The surface analysis confirmed that the calcination at 250°C exhibited nanoclutser like NiO with average particle size of ∼6nm. While increasing the calcination temperature beyond 250°C, hexagonal shaped NiO is observed with enhanced particle sizes. The electrochemical performance confirmed the good redox behavior of NiO electrodes. Moreover, NiO with average particle size of ∼6nm exhibited high specific capacitance of 449F/g at a scan rate of 5mV/s compared to other samples with particle sizes of ∼21nm (323F/g) and ∼41nm (63F/g). This is due to the good ion transfer mechanism and effective electrochemical utilization of the working electrode.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Herein, zinc cobaltite (ZnCo2O4) nanoparticles (synthesized via hydrothermal treatment) were blended with polyaniline (PANI) (synthesized via chemical oxidative polymerization) to form PANI-ZnCo2O4 ...nanocomposite. The structural crystallinity and phase purity of PANI-ZnCo2O4 nanocomposite were authenticated by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The morphological studies showed that the spinel structured ZnCo2O4 nanoparticles were well embedded on tubular-shaped PANI matrix, suggesting the effective connection between ZnCo2O4 nanoparticles with PANI matrix. The electrochemical performance studies of PANI-ZnCo2O4 nanocomposite for supercapacitor exhibited enhanced specific capacity of 398 C/g at a current density of 1 A/g as compared with ZnCo2O4 nanoparticles and PANI. The enhancement of electrochemical performance was contributed from the augmentation of electroactive sites for redox reaction, rapid electron transfer rate and the synergistic effect of ZnCo2O4 nanoparticles and highly conductive PANI. The fabricated PANI-ZnCo2O4//activated carbon based hybrid supercapacitor achieved high energy density (13.25 Wh/kg at 375 W/kg) as well as excellent cycling stability (∼90% retention after 3000 cycles). Furthermore, PANI-ZnCo2O4 nanocomposite was employed as a hydrazine sensor which exhibited good sensitivity of 0.43 μA μM−1 in the linear range of 0.1–0.6 mM with a low detection limit of 0.2 μM.
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•The PANI-ZnCo2O4 nanocomposite was prepared via blending process.•Dual roles of PANI-ZnCo2O4 in supercapacitor and electrochemical sensor.•High energy and power density was obtained in asymmetric supercapacitor.•PANI-ZnCo2O4 showed high sensitivity towards hydrazine.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The performance of a supercapattery depends on its energy density, rate capability of charge and discharge and stability of electrode. Here in, a sonochemical method followed by calcination was ...applied to synthesize nickel phosphate-silver phosphate (Ni3(PO4)2Ag3PO4) nanocomposites. Morphological studies revealed that crystalline Ag3PO4 (∼10 nm) was intimately anchored on the surface of amorphous Ni3(PO4)2, which benefits efficient charge transfer between the two metal phosphates. The optimized Ni3(PO4)2Ag3PO4 nanocomposite electrode exhibited a significant boost in rate capability from 29% (Ni3(PO4)2) to 78% capacity retention with the maximum specific capacity of 478C/g at 1 A/g in 1 M KOH electrolyte. The enhancement of rate capability originated from a more rapid electron-transfer rate and an augmentation of electroactive sites for electrolyte ion diffusion from the interfaces of porous Ni3(PO4)2 and an improvement in the electrical conductivity of crystalline Ag3PO4. The fabricated Ni3(PO4)2Ag3PO4//activated carbon-based supercapattery exhibited an energy density of 32.4 Wh/kg at 399.5 W/kg and excellent cyclic stability (∼82% capacity retention after 5000 cycles).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
This article presents the effect of polyaniline (PANI) embedded copper cobaltite (CuCo2O4) as an electrode material for high performance supercapacitor application. The composite of PANI-CuCo2O4 was ...prepared via blending process. The formation of PANI-CuCo2O4 composite was confirmed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The surface morphologies showed that the spinel structure of CuCo2O4 (average particle size of 30nm) was well distributed on PANI matrix, suggest the effective intercalation of CuCo2O4 with PANI matrix. The electrochemical properties of CuCo2O4, PANI and PANI-CuCo2O4 composite were investigated using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) in 1M of KOH as an aqueous electrolyte. The PANI-CuCo2O4 composite showed the improved specific capacitance of 403C/g than that of pure CuCo2O4 and PANI.The enhanced electrochemical performance was obtained due to the augmentation of redox active sites and synergetic effect between PANI and CuCo2O4 nanoparticles. Additionally, the fabricated (activated carbon (AC)/PANI-CuCo2O4) asymmetric supercapacitor device can be cycled reversibly at a cell voltage of 1.5V, which exhibited excellent electrochemical performances with an energy density of 76Wh/kg and a power density of 599W/kg. It also presented a superior life cycle with 94% capacitance retention after 3000 cycles.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
