Application Of Energy Storage Materials Research Articles

Oxygen-enriched vacancies Co3O4/NiCo2O4 heterojunction hollow nanocages with enhanced electrochemical properties for supercapacitors

Research into environmentally friendly energy storage devices is a vital strategy to address the energy crisis and environmental pollution challenges. In this paper, oxygen-rich vacancy Co3O4/NiCo2O4 heterojunction hollow nanocage electrodes were synthesized by a two-step hydrothermal and calcination method. Taking advantage of its unique structure, oxygen vacancies, and the synergistic effect of multi-element transition metal oxides, the electrode has good conductivity, high specific surface area, and abundant active sites. As a result, the Co3O4/NiCo2O4 HHNCs electrode exhibits an ultra-high specific capacitance of 1788F g−1 at 1Ag-1, and the assembled hybrid supercapacitor has an energy density of up to 43.9 Wh kg−1, which is promising for applications in energy storage materials.

Operando small-angle neutron scattering and its applications in energy storage materials

<i>Operando</i> small-angle neutron scattering and its applications in energy storage materials

Achieving high comprehensive energy storage properties of BNT-based ceramics via multiscale regulation

It is difficult to obtain high polarization strength and high breakdown strength synchronously, resulting in the drawback of lower energy storage density, which inhibits commercial application of energy storage materials. We have successfully prepared (1-x)(0.93Bi0.5Na0.5TiO3-0.07CaSnO3)-xSrTiO3 (BNT–CS–xST) ceramics by solid-state method. The presence of polymorphic nanodomains and the large electric displacement generated by the high charge Sr2+-Sr2+ ion pairs help to delay saturation polarization (Pm ∼ 48.64 μC/cm2 at 315 kV/cm). In addition, the breakdown field strength (Eb) is increased by grain refinement and increasing the band gap. It is noteworthy that a high recoverable energy storage density (Wrec = 4.2 J/cm3) and a great efficiency (η = 88%) were achieved simultaneously in BNT–CS–0.5ST ceramic. Moreover, excellent charge-discharge performance was also achieved, with a discharge energy density Wd of 2.2 J/cm3, a current density CD of 1724 A/cm2 and a power density PD of 250 MW/cm3. The study demonstrates that the great potential of BNT–CS–xST ceramics in power storage devices and provides an effective strategy for designing ceramics dielectric capacitors with excellent performance.

Reduced Graphene Oxide-Tailored CuFe2O4 Nanoparticles as an Electrode Material for High-Performance Supercapacitors

Transition metal oxide-based magnetic nanocomposites attract great attention due to their unique properties and applications in the field of energy storage. Herein, we present a facile microwave procedure for the synthesis of CuFe2O4 (CF) and CuFe2O4 incorporated with reduced graphene oxide CuFe2O4/rGO (CG) as potential electrode materials for hybrid supercapacitor. The structure and morphology of CF and CG nanoparticles are examined. The electrochemical performance is studied in 6 M aqueous KOH electrolyte using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques. The attractive CG nanocomposite exhibits high specific capacity of 800 C/g at a current density of 2 A/g and better cycling stability when compared to pure CF, due to the formation of nanostructure composed of ferrite nanoparticles homogeneously incorporated onto rGO sheets. Furthermore, the practicability of CG electrode is investigated by the fabrication of CG and activated carbon. The hybrid supercapacitor device shows excellent electrochemical performance with specific energy of 18.3 Wh/kg and a specific power of 455 W/kg. It is noteworthy that the cyclic stability is excellent with a capacity retention of ~98% after 3000 cycles manifesting the superiority of CG electrode. The proposed device demonstrates the potential to fabricate other metal oxides with activated carbon via a facile synthesis method for promoting application in energy storage materials and promoting new opportunities of binary nanocomposite.

Investigation on thermal conductivities of pentaerythritol-graphene composites for thermal energy storage

Low thermal conductivity is one of the major disadvantages that limit the practical application of energy storage materials. In this paper, the thermal physical properties and thermal conductivity of the composite phase change materials, in which the pentaerythritol is used as the matrix material and graphene/alumina as the thermal conductive fillers, is respectively investigated with experimental research and simulation analysis. The DSC results show that the specific heat capacity (25 °C) of the composite is improved because of the graphene. Additionally, the addition of graphene makes the phase change temperature and latent heat value of phase change slightly increase. As the mass percentages of thermal conductive filler increases, the thermal conductivity of pentaerythritol-graphene(PE-GE) as well as pentaerythritol-alumina(PE-Al2O3) composite increases gradually, but graphene has a more excellent effect. With increasing the mass fractions of graphene, the changing trend of interfacial thermal conductivity is consistent with the overall thermal conductivity because of that the interfacial thermal conductivity characterizes the combination of thermally conductive fillers and matrix materials, and the local promotion will affect the whole. Furthermore, the graphene structure changes towards better combination and more uniform dispersion with pentaerythritol as the increase of carbon atom spacing in graphene. In addition, the promoted overall thermal conductivity of the composite benefits from the structural change of the thermal conductive filler.

Synthesis of different new copolyimides and influence of different molar ratios of diamines and dianhydride on pseudocapacitance performance of p-type conductive polymer

In the present work, poly ortho aminophenol/copolyimides (POAP/PI) composites were prepared using PIs together with POAP. PIs were synthesized using different molar ratios of diamines and dianhydride by polymerization method. Different electrochemical methods including cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS) were applied to study system performance. Presence of PIs in the composite films improved mechanical and electrochemical performance of the p-type conductive polymer. This study reveals that POAP/PI with high specific capacitance and long cycle-life is suitable for application in energy storage materials.

Influence of different N‑benzoyl derivatives of isoleucine on electrochemical properties and pseudocapacitance performance of conductive polymer electroactive film: Electrochemical and theoretical study

Three newly synthesized N‑benzoyl derivatives of isoleucine (3‑methyl 2‑[(4‑methylbenzoyl) amino] pentanoic acid (C-Me(, 2‑(benzoyl amino) 3‑methyl pentanoic acid (C-H) and 2‑[(4‑chlorobenzoyl) amino] 3‑methyl pentanoic acid (C-Cl) were synthesized via Schotten-Baumann method. Afterward, dealing with improving electrochemical properties of the poly ortho aminophenol (POAP), we fabricated POAP/C-Me, POAP/C-H and POAP/C-Cl films through electro-polymerization of POAP by employing of N‑benzoyl derivatives of isoleucine to consider as the active electrode for SCs. Based on the electronic wave function (DFT-method), the local intramolecular the electron density and its Laplacian, corresponding to atomic electronic kinetic energy, and molecular virial forces (in the molecular planes) of the molecular system is studied in this work calculated. Analysis of these results show that the atomic-scale electronic properties are generally depend on the bonding and electronic molecular structures and electron donating group on the N‑benzoyl derivatives has main important effect rather than electron withdrawing group. Based on electrochemical analyzing of POAP/C-Me, the specific capacitance, retention capacity and cycle stability as desirable factors in electrochemical SCs, exhibited more improved performances than electron withdrawing group in POAP/C-Cl film. According to electrochemical and quantum chemical evaluation, C-Me has improvement effect on electrochemical performance of POAP/C-Me electroactive film. This study reveals that POAP/C-Me with high fractal dimension, high specific capacitance and long cycle-life is suitable for application in energy storage materials.

Partially graphitic nanoporous activated carbon prepared from biomass for supercapacitor application

In this present work, the preparation of partially graphitic nanoporous carbon from biomass (bamboo bagasse) is carried out using potassium ferrocyanide and -KOH as activating agent with controlled temperature and gas flow rates. The physico-chemical properties of biomass-derived graphitic nano-porous carbon were characterized by X-ray Diffraction (XRD), Fourier Transform Infra-Red Spectroscopy (FTIR), Thermal Gravimetric Analysis (TGA), Raman spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and electrochemical measurements. It is interesting that the activation with the iron salts plays a significant role in the formation of graphitic structures. The graphitic nanoporous carbonaceous materials show high specific surface area of 1360 m2 g−1, low impedance, large pore volume and high specific capacitance. Thus, the iron-catalyzed graphitic carbon is excellent candidate for the supercapacitor applications. This contemporary- novel method to synthesis of nanoporous carbon represents a great potential for apparent and diversified applications in energy storage materials.

Lithium-Catalyzed Carbon Aerogel and Its Possible Application in Energy Storage Materials

A lithium-based catalyst for carbon aerogel compounds and carbon nanotubes synthesis was used. Lithium hydroxide-catalyzed and CNT-modified carbon aerogel was compared to traditionally synthesized sodium carbonate-catalyzed carbon aerogel, as well as to the same material modified with CNT to evaluate the real effect of lithium hydroxide addition. Enhancement in the specific surface area from 498 m2/g to 786 m2/g and significant change in pore size distribution were observed. Low temperature, supercritical drying in carbon dioxide was used to prepare an organic aerogel with subsequent pyrolysis in an inert gas flow to convert it into carbon aerogel. The as-obtained material was examined with respect to energy storage applications, i.e. symmetric hybrid supercapacitors. It was shown that lithium hydroxide was responsible for shorter gelation time, increased specific surface area, and a greater number of micropores within the structure. For both reference materials prepared using sodium carbonate, quite different data were recorded. It was presented that the proper choice of carbon matrix should combine both high specific surface area and appropriate pore size distribution. High surface area and a relatively large number of micropores were responsible for specific capacity loss.

A silicon-based two-dimensional chalcogenide: growth of Si₂Te₃ nanoribbons and nanoplates.

We report the synthesis of high-quality single-crystal two-dimensional, layered nanostructures of silicon telluride, Si2Te3, in multiple morphologies controlled by substrate temperature and Te seeding. Morphologies include nanoribbons formed by VLS growth from Te droplets, vertical hexagonal nanoplates through vapor-solid crystallographically oriented growth on amorphous oxide substrates, and flat hexagonal nanoplates formed through large-area VLS growth in liquid Te pools. We show the potential for doping through the choice of substrate and growth conditions. Vertical nanoplates grown on sapphire substrates, for example, can incorporate a uniform density of Al atoms from the substrate. We also show that the material may be modified after synthesis, including both mechanical exfoliation (reducing the thickness to as few as five layers) and intercalation of metal ions including Li(+) and Mg(2+), which suggests applications in energy storage materials. The material exhibits an intense red color corresponding to its strong and broad interband absorption extending from the red into the infrared. Si2Te3 enjoys chemical and processing compatibility with other silicon-based material including amorphous SiO2 but is very chemically sensitive to its environment, which suggests applications in silicon-based devices ranging from fully integrated thermoelectrics to optoelectronics to chemical sensors.