Electrode Material For Supercapacitor Applications Research Articles

Supercapacitor applications of 2_aminoisobutyric acid-mediated N-doped graphene

N-doped graphene has been synthesized by the reduction of graphene oxide (GO) using 2-aminoisobutyric acid (AIB) as a reducing agent (N-GrAIB) under mild experimental conditions in aqueous medium. The reduction of GO was indicated by a change in its optical absorption as well as by its Raman spectrum and 13C solid state magic angle spinning (MAS) nuclear magnetic resonance (NMR) studies. The latter two techniques also confirmed the doping of N. N-GrAIB exhibited fairly high conductivity (6.3 S/cm), high specific capacitance (228 F/g at 1 A/g) with good cycling stability for 1000 charge-discharge cycles, high coulombic efficiency (100-101%) and high energy density of 20.26 Wh/kg at a power density of 400 W/kg. The present work shows that this environmental benign N-doped graphene (N-GrAIB) could be a promising electrode material for supercapacitor applications. Copyright © 2016 VBRI Press

Designing nanosheet manganese cobaltate@manganese cobaltate nanosheet arrays as a battery-type electrode material towards high-performance supercapacitors

Binder-free hierarchical nanosheet manganese cobaltate@manganese cobaltate nanosheet arrays (NS MnCo2O4@MnCo2O4 NSAs) heterostructures have been successfully deposited on nickel (Ni) foam surface using a facile two-step hydrothermal process. Scanning electron microscope characterization illustrate that the as-developed composite exhibits a growth of smaller MnCo2O4 nanosheet structures anchored on the surface of MnCo2O4 NSAs that provide abundant reactive sites and effective electronic transmission, endowing the NS MnCo2O4@MnCo2O4 NSAs an outstanding electrochemical performance. The electrochemical measurements reveal that the as-prepared NS MnCo2O4@MnCo2O4 NSAs delivers a Faradic battery-type redox behavior, which is distinct from the behaviors of carbon-based materials. As a battery-type material, NS MnCo2O4@MnCo2O4 NSAs exhibits an outstanding specific capacity (135.15 mA h g−1 at 2 A g−1) and remarkable rate capability (82.93%), which are much higher than that of bare MnCo2O4 NSAs. Moreover, NS MnCo2O4@MnCo2O4 NSAs delivers an excellent cycling stability of 88.74% over 5000 cycles. Hence, these electrochemical results suggest that the as-developed NS MnCo2O4@MnCo2O4 NSAs can serve as an advanced battery-type electrode material for supercapacitor applications.

Pseudocapacitive nanostructured silver selenide thin film through room temperature chemical route: First approach towards supercapacitive application

Well controlled growth of pseudocapacitive nanostructured silver selenide (Ag2Se) thin film has been achieved through simple, less expensive, room temperature and industry scalable successive ionic layer adsorption and reaction (SILAR) method onto stainless steel substrate to use as electrode material for supercapacitor application as the first report. X-ray photoelectron spectroscopy studies confirmed the formation of Ag2Se. Orthorhombic structure of grown Ag2Se thin film exhibits hydrophilic nature in aqueous Na2SO3 electrolyte yielding specific capacitance of 112.45 F/g @ 10 mV/s scan rate studied through cyclic voltammetry (CV) and 115.99 F/g @ 0.8 A/g by galvanostatic charge discharge through electrochemical studies. Interestingly Ag2Se electrode exhibits 85.10 % capacitive retention after 2000 CV cycles. Origin of net-charge stored at the electrode–electrolyte interface has been well understood from surface induced capacitive and diffusion-controlled mechanisms. Low equivalent series resistance (ESR) value of 0.06 Ω was determined by the plot of iRdrop vs. current density exhibiting high-power burst electrode material.

Synthesis and characterization of Cu0.92Co2.08O4 nanoplates for supercapacitor electrode application

In this endeavor, the Cu0.92Co2.08O4 materials were prepared by CTAB assisted hydrothermal technique with calcination process. The cyclic voltammetric analysis exhibit the specific capacitance of 543 Fg−1 at a scan rate of 5 mVs−1 whereas the galvanostatic charge/discharge studies provide the specific capacitance of 489 Fg−1 at a current density of 1 Ag−1. The Cu0.92Co2.08O4 nanoplate possesses low internal and charge discharge resistance which exhibit 93% of initial capacitance after 2000 continuous cyclic voltammetric cycles at a scan rate of 100 mVs−1. These results indicate that the prepared Cu0.92Co2.08O4 nanoplate is the significant electrode material for supercapacitor application.

Effect of deposition potential and annealing on performance of electrodeposited copper oxide thin films for supercapacitor application

The present investigation describes the effect of deposition potential and annealing on copper oxide (CuO) thin film as a supercapacitor electrode. CuO thin films were grown on conducting glass substrate (ITO) by electrodeposition at room temperature and annealed for 3 hrs. at 300° C. The formation of polycrystalline CuO was confirmed by X-ray diffraction (XRD) & X-ray photoelectron spectroscopy (XPS). Significant change in morphology of CuO thin films after annealing has been observed. Annealing has improved crystallinity, surface coverage and grain connectivity of CuO thin films. CuO thin films deposited at −450 mV vs. Ag/AgCl exhibits essential porosity for electrochemical reactions. Higher deposition potential of −500 mV vs. Ag/AgCl leads to formation of compact CuO thin films. Electrochemical performance of as deposited and annealed CuO thin films were compared using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) in 1 M aqueous KOH electrolyte. The maximum specific capacitance of 57.44 F/g at 20 mV/s was measured. The CuO thin film shows specific energy of 2.67 Wh/kg with a coulombic efficiency of 77.27 % at 0.5 mA/cm2 current density. These results showed that the electrodes prepared by simple, low-cost electrodeposition method can be promising electrode materials for supercapacitor application.

Template and binder free 1D cobalt nickel hydrogen phosphate electrode materials for supercapacitor application

Herein, we synthesized 1D bimetallic hydrogen phosphate [CoxNix(HPO4)] nanorods by using a simple and effective chemical bath deposition method for supercapacitor applications. The prepared CoxNix(HPO4) was analyzed by Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) pattern. The surface morphology was envisaged by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) methods. The porous nature and surface area of the materials were characterized by nitrogen sorption isotherm and a high specific surface area of 153 m2 g−1 was found to be for Co0.75Ni0.25(HPO4). The Co0.75Ni0.25(HPO4) displays a maximum specific capacity of 475 mA h g−1 at 1 A g−1 in a three-electrode configuration using 3 M KOH as the electrolyte. Co0.75Ni0.25(HPO4) exhibits almost 94.8% of its initial specific capacity over 5000 GCD cycles at 10 A g−1. Furthermore, the fabricated asymmetric supercapacitor (ASC) with Co0.75Ni0.25(HPO4) and activated carbon (AC) showed a high specific capacitance of 182.5F g−1 at 0.5 A g−1. The ASC device delivered a maximum energy density of 64.88 Wh kg−1 at a power density of 800 W kg−1.

Synergistic effect of sulfur-doped reduced graphene oxide created via microwave-assisted synthesis for supercapacitor applications

Doping heteroatoms is an effective means of modifying the electrochemical properties of reduced graphene oxide (rGO). In this work, we propose the modification of rGO via microwave-assisted synthesis with different concentrations of sulfur at 140 °C for 30 min. Characterization using X-ray diffraction, Fourier-transform infrared, and Raman spectroscopy revealed successful doping with sulfur to alter the physical properties of rGO. The morphology of doped S-rGO samples exhibited wrinkling and folding of graphene sheets. Electrochemical evaluation revealed S-rGO with 0.25 M of sulfur (S-rGO-0.25) to have excellent electrochemical performance, with a specific capacitance of 237.6 F g−1 compared to the S-rGO with 0.15 M (S-rGO-0.15) and S-rGO with 0.50 M (S-rGO-0.50) with 98.2 and 61.7 F g−1 respectively. Furthermore, S-rGO-0.25 was validated as having an outstanding capacitance retention of 106% after 10,000 cycles signifying that it has promising potential as an electrode material for supercapacitor applications.

Nitrogen and phosphorous Co-Doped Laser-Induced Graphene: A High-Performance electrode material for supercapacitor applications

A versatile and cost-effective strategy is demonstrated to produce N and P co-doped laser-induced graphene (NP-LIG) based on a duplicate laser pyrolysis method. The dopant precursor concentration and laser power significantly affected the surface chemistry and electrochemical performance of the NP-LIG. The NP-LIG optimized with 3 wt% H3PO4 and laser power of 3.5 W (NP3-LIG-3.5) in the second pyrolysis step demonstrated an impressive specific areal capacitance (CA) of 163.6 mF/cm2 at 0.2 mA/cm2 in a three-electrode system where 1 M H2SO4 was used as an aqueous electrolyte. Furthermore, the solid-state NP3-LIG-3.5 supercapacitor (NP3-LIG-SC) assembled with a gel electrolyte (PVA-H2SO4) showed a high CA of 69.7 mF/cm2 at 0.05 mA/cm2, which is 4 and 13 times higher, respectively, than those of N-doped LIG and singly pyrolyzed LIG SCs. In addition, the NP3-LIG-SC exhibited good cycling stability (capacitance retention of 84% after 10,000 cycles), a Coulombic efficiency of approximately 100%, and a high areal energy density of 9.67 µWh/cm2. This study proposes a facile method for the fabrication of heteroatom-co-doped LIG electrodes for use in flexible and wearable electronics.

MnO2@polypyrrole composite with hollow microsphere structure for electrode material of supercapacitors

In this work, a new MnO2@polypyrrole mesoporous composite with hollow microsphere structure is synthesized using PS (polystyrene) beads as the hard template. In 1 M Na2SO4 solution, it exhibits a specific capacitance value of 295F g−1 at the current density of 1 A g−1. After 20,000 charge/discharge cycles at the current density of 10 A g−1, the capacitance retention rate is 100%. The MnO2@H-PPy (1:4)-based asymmetric supercapacitor shows a specific capacitance of 63F g−1 in a potential window of 0 to + 2.2 V at the current density of 1 A g−1. The energy density is 42 Wh kg−1 and the power density is 1100 W kg−1, which proved to be a promising candidate for the electrode materials in supercapacitor applications.

A comparative study on the electrochemical capacitor performance of 1T/2H hybridized phase and 2H pure phase of MoS2 nanoflowers

The 1T/2H hybridized and 2H pure phases of MoS2 nanoflowers were synthesized in a one-step hydrothermal process with the molybdenum source as sodium molybdate dihydrate and the sulfur source as thiourea. The as-prepared 1T/2H hybridized and 2H pure phases of MoS2 were investigated using a thermogravimetry\\differential thermal analysis, powder x-ray diffraction, field emission scanning electron microscopy, and energy-dispersive x-ray spectroscopy. The obtained 1T/2H hybridized phases of MoS2 were confirmed by the Raman spectroscopy. The electrochemical characteristics of MoS2 electrodes were examined using cycle voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy. The electrodes are based on the 1T/2H hybridized phases MoS2 with specific capacitance (C p) of 555.4 F g−1 at current densities (C d) of 0.5 A g−1, capacity retention ratio of 85% after 10 000 cycles were observed that could be a strong potential electrode material for supercapacitors application.

Lignin Derived Porous Carbons: Synthesis Methods and Supercapacitor Applications.

Lignin, one of the renewable constituents in natural plant biomasses, holds great potential as a sustainable source of functional carbon materials. Tremendous research efforts have been made on lignin-derived carbon electrodes for rechargeable batteries. However, lignin is considered as one of the most promising carbon precursors for the development of high-performance, low-cost porous carbon electrode materials for supercapacitor applications. Yet, these efforts have not been reviewed in detail in the current literature. This review, therefore, offers a basis for the utilization of lignin as a pivotal precursor for the synthesis of porous carbons for use in supercapacitor electrode applications. Lignin chemistry, the synthesis process of lignin-derived porous carbons, and future directions for developing better porous carbon electrode materials from lignin are systematically reviewed. Technological hurdles and approaches that should be prioritized in future research are presented.

Investigations on ternary transition metal ferrite: NiCoFe2O4 as potential electrode for supercapacitor prepared by microwave irradiation method

Ternary transition metal ferrite (NiCoFe2O4) has been successfully produced by a facile microwave-assisted method as an electrode material for supercapacitor applications. The structural single-phase nature is analysed by XRD pattern reveals the material belongs to cubic spinel structure with space group Fd3¯m. In addition, Rietveld refinement is used to confirm the structure from the powder X-ray diffraction data. The maximum entropy method also has been applied to find the electronic charge density that exists around the cation and anion sites in the compound. The UV spectral studies show the prepared nanomaterials have band gap of 1.43 eV and the magnetic studies confirm a ferromagnetic type with magnetization value of 0.615 emu g−1 and coercivity as 920.38 Oe. Using a three-electrode system, the electrochemical performance of the prepared nanomaterial is assessed by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic process in 3 M KOH electrolyte. The highest specific capacitance value of 314.97 F g−1 is observed at the scan rate of 5 mV s−1. The maximum energy density and power density values are 3.826 Wh Kg−1 and 1249.326 W Kg−1 respectively. It also has good retention of 93.65% for 5000 cycles at a current density 3 A g−1. Furthermore, an asymmetric supercapacitor device is fabricated which exhibits very high energy and power density of 6.4 Wh Kg−1 and 1904.7 W Kg−1 at a current density 10 A g−1.

Less Expensive and Eco-Friendly Preparation of Activated Carbon Derived from Coffee Leaf as an Supercapacitors Electrode

In this paper, less expensive and eco-friendly biomass-based activated carbon from coffee leaf (CL) was prepared as electrode materials for supercapacitor applications using KOH activation, carbonization, and physical activation in a CO2 atmosphere. Using cyclic voltammetry and galvanostatic charge/discharge techniques, the CL sample was tested in a two-electrode configuration operating in 1 M H2SO4. After physical activation, the percentage reduction of the mass, diameter, thickness, and diameter are 76.47%, 29.38%, 28.57%, and 38.04%, respectively. The CL sample exhibits specific capacitance, energy and power densities of 210 F/g, 29.17 Wh/kg, and 39.99 W/kg at constant current 1 A, respectively. Therefore, the CL sample obtained through KOH activation, carbonization, and physical activation using CO2 atmosphere has a promising future applied as an electrode material for supercapacitor applications.

Synthesis, characterization, and cytotoxicity of self-assembly of hybrid nanocomposite modified membrane of carboxymethyl cellulose/graphene oxide for photocatalytic antifouling, energy storage, and supercapacitors application

In this work, carboxymethylcellulose (CMC) macrostructure has been incorporated with graphene oxide nanosheet (GO) to form a hybrid composite as a modified surface for antifouling membrane and supercapacitor applications. The hybrid nanomaterial (HNM) has been synthesized successfully and characterized via various tools, such as scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV-Vis), and X-ray diffraction (XRD). A modified surface of Graphene oxide/ Cellulose (GO@CMC) has been studied by cyclic voltammetry technique for detecting the electrochemical properties, supercapacitor, and energy storage. Also, the optical properties of the modified antifouling surface of the HNM membrane were detected by UV-spectroscopy apparatus for water treatment applications. For proving the easily, the electron transfer of GO@CMC via the photocatalytic process for degradation of organic and inorganic pollutions, such as methylene blue (MB) dye. The cytotoxicity of fabricated HNM has been studied with two cell lines such as Breast Cancer cell line (MDA-MB-231) and the other was Hepatocellular carcinoma cell line (HepG2), the following results have been obtained: - A good electron transfer has been detected with GO@CMC HNM. - Easily the photocatalytic process with organic compounds pollution. - GO@CMC HNM has effects observably on the cell lines of MDA-MB-231 and HepG2. - Results demonstrated that the fabricated HNM is promising electrode material for supercapacitors application and energy storage.

Role of Electrolytes in Electrochemical Properties of La2SrV2O9–rGO Composite as Electrode Material

The rising need to store energy intermittently offers excellent opportunities for supercapacitors with high potential storage capabilities. In this work, we explore the La2SrV2O9–rGO composite material for supercapacitor application. The crystallographic properties, morphological, optical, and electrochemical properties of La2SrV2O9–rGO composite and bare La2SrV2O9 prepared via chemical precipitation method are investigated to estimate their potential for energy storage. We further illustrate the unique role of rGO towards the variations in capacitance, by varying the different electrolyte solutions such as H2SO4 and NaOH. Cyclic voltammetry studies reveal the quasi-rectangular profiles which confirm the electrochemical double layer and Faradic capacitance behaviours upon employing both electrolytes. The capacitance of La2SrV2O9–rGO in acidic and alkaline environment are 428.12 and 212.6, similarly for La2SrV2O9 in acidic and alkaline are 380.6 and 324.6 F g−1 respectively. Specific capacitance calculated using current density and obtained 450 F g−1 and 47 F g−1 at 0.5 A g−1 for La2SrV2O9–rGO in acidic and alkaline electrolyte. H2SO4 is a strong electrolyte, it donates protons and ionises completely. As the result, capacitance increases for acidic electrolyte while it decreases for alkaline electrolyte. Our results emphasize the role of electrolyte interaction with La2SrV2O9 and La2SrV2O9–rGO to achieve better capacitance values. The obtained results found to be promising in the development of La2SrV2O9 with rGO as suitable electrode material for supercapacitor applications.

Metal-organic framework materials for supercapacitors

Supercapacitor (SCs), known as outstanding electrical storage capacity, which times more than the batteries and fuel cells, recharges with a large amount of released power, fast overpassing the gap between capacitors and batteries, and widely be employed in the field of energy storage. Metal-organic frameworks (MOFs) attract intensive attention as electrode materials in supercapacitor application, owing to their ultrahigh porosity, adjustable distribution of pore size, convenient synthesis, great structural adaptability, etc. Composited with different materials, such as carbons family, metal oxide, can improve pristine MOFs’ conductivity and chemical stability, which are all-important as electrode materials in SCs. This review comprehensively summarizes the common synthesis methods of four kinds of MOFs materials: the pristine MOFs, MOFs composites, MOFs-derived nanoporous carbons, and MOFs-derived metal oxides. Also, the applications of these four kinds of materials in SCs electrode materials are systematically introduced. Furthermore, a perspective on MOFs materials in the field of SCs is discussed.

Tuning the crystallinity of ZrO2 nanostructures derived from thermolysis of Zr-based aspartic acid/succinic acid MOFs for energy storage application

This paper investigated the effect of calcination temperatures on the structural, and capacitance of Zr-MOFs as an electrode material for supercapacitor applications. MIP-202 and 203 were prepared solvothermally, using zirconium clusters with aspartic acid and succinic acid as ligands, respectively. These MOFs are subject to heat treatment at 350 and 500 °C to be converted to ZrO2 derived from MOFs. As a result, we have six materials: MIP-202 (bare), MIP-202 (350 °C), MIP-202 (500 °C), MIP-203 (bare), MIP-203 (350 °C), and MIP-203 (500 °C). The structure of compounds were confirmed by X-ray diffraction analysis (XRD), N2 adsorption–desorption measurements, scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS). We investigated the differences in electrochemical properties in the amorphous and crystalline phases. The electrochemical performances of fabricated electrodes, including as-prepared Zr-based MOFs before heat treatment (MIP-202, MIP-203) and after that, at 350 and 500 °C, are demonstrated via electrochemical tests in a three-electrode configuration. Among the materials, MIP-202 (350) exhibits the best electrochemical efficiency due to its amorphous structure and high specific surface area, delivering a high specific capacitance of 308 F g−1 at a current density of 2 A g−1. To further identifying electrochemical properties of the electrode, an asymmetric supercapacitor was constructed utilizing graphene oxide (GO) as the anode and MIP-202 (350) as the cathode. The device provided long cyclic life durability (86 % specific capacitance maintenance after 3000 cycles) and high energy density of 16.06 Wh kg−1 and high-power density 40,000 W kg−1.

A new hierarchically porous Cu-MOF composited with rGO as an efficient hybrid supercapacitor electrode material

Exploring new materials for efficient energy storage is imperative to derive uninterrupted energy supply from non-conventional sustainable sources. The present paper reports on the synthesis of a new Cu-MOF (HMRL-1), involving the reaction of a tetracarboxylic linker and Cu2+ salt under solvothermal conditions. Using a simple ultrasonication approach, the as-synthesized MOF has been further used to fabricate a composite with reduced graphene oxide (rGO) (R). The resulting composite (HMRL-1/R) has been explored as a binder-free supercapacitor electrode material for deriving enhanced charge storage capacity. The supercapacitor performance of the composite material has been investigated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). The electrochemical investigations reveal that HMRL-1/R composite exhibits hybrid capacitive features with a specific capacitance (CS) of 366.6 Fg−1 at 1 Ag−1 and excellent cyclic stability and performance retention, which is much higher than that of pristine HMRL-1 and R due to their synergistic effect. All the findings suggest that as-prepared material is a promising candidate for an electrode material in supercapacitor applications.

Microporous carbon derived from anthracite as supercapacitor electrodes with commercial level mass loading

Porous carbon is considered as an ideal electrode material for supercapacitor applications. Meanwhile, converting coal into cleaner energy storage materials accords with the concept of green development nowadays. Herein, microporous carbons derived from anthracite (AMCs) were prepared via a simple KOH activation, which possess ultrahigh specific surface area (up to 2947 m2 g−1), developed pore structure (1.473 cm3 g−1 total pore volume) and considerable yield (≥42.3%). The optimized sample (AMC800) achieves largest micropore volume (0.947 cm3 g−1) and superior conductivity (976.56 S m−1). Therefore, AMCs reveals excellent electrochemical performances as electrode material with commercial level mass loading (∼10±0.5 mg cm−2). In aqueous electrolyte, the assembled SCs present outstanding specific capacitance (up to 282 F g−1 at 0.5 A g−1) and high rate performance (87.23% at 10 A g−1). For organic system, AMC800-based SC delivers superior energy density (34.08 Wh kg−1) and remarkable cycling stability (93.45% retention after 10,000 cycles), which are superior to supercapacitor grade commercial carbon (YP-50F). Hence, this work is significant to the actual production of coal-based porous carbon and its commercial application as supercapacitors electrode material.

Bioinspired synthesis of nickel oxide nanoparticles as electrode material for supercapacitor applications

Bioinspired synthesis of nickel oxide nanoparticles as electrode material for supercapacitor applications