batterydata/paper-abstracts huggingface dataset:
In this report, we investigate the electrochemical capacitance and redox behaviour of a stand-alone polyaniline–poly(vinyl alcohol) composite film cast on an insulating substrate (normal printer paper) and compared it with an electrochemically synthesized composite film deposited on a gold electrode. The stand-alone composite film showed timescale-dependent, wide range charging–discharging redox cycling and high electrochemical capacitance in potentiodynamic electrochemical experiments carried out in 1M HCl solution. The stand-alone composite film exhibited two distinct current density responses during redox switching. This might be attributed to the different doping and de-doping modes, represented by ions trapped at deep and shallow levels in the bulk of the composite polymer film and the double layer of the modified electrode–electrolyte interface. The wider electrochemical window and higher capacitance response of the stand-alone film are important for battery technology and in energy storage and conversion devices.
A highly oxidized lithium manganospinel, Li2Mn4O8+z , was prepared from LiMnO4 and MnCO3 precursors. The effect of synthesis temperature, time, and oxygen partial pressure on the extent of oxidation of the material was investigated by thermogravimetry (TG). X-ray diffraction (XRD), potentiometric titration, thermogravimetry, and elemental analyses were used to determine the stoichiometry of the product.
In this work the development, tests and thermodinamic numerical simulations on a flat cell of an innovative Sodium-metal-halide battery has been presented: a prototype of a single cell was designed, realized and eventually extensively tested at CNR-ITAE. The following performances were recorded during the test stage: 76% energy efficiency and 84% faradic efficiency. Similarly to tubular cells commercially available, the flat cells constituting the battery have to be placed into an insulated box equipped with a proper heating system because of their high working temperatures. To this aim, a numerical thermal analysis by using the software COMSOL MULTIPHYSICS has been carried out to evaluate the best solution to guarantee a reduced thermal loss and reasonable warming up time.
We demonstrate here an effective strategy to construct three-dimensional (3D) metal-graphene based film electrodes. The build blocks are tin nanopartilces well anchored on graphene sheets which were synthesized by a feasible and controllable in situ solvothermal method and a subsequent thermal reduction process. In this study, we found the solvent type is the key and only with organic solvent (ethanol) the desired 3D graphene sheets anchored tin nanoparticles (Sn/GS) films can be obtained. The graphene oxide (GO), which is the original source of conductive GS network, can also serve as a surfactant to inhibit the secondary aggregation of nanoparticles. Accordingly, the homogeneous Sn nanoparticles (∼10nm) can evenly distribute into the GS matrix. The as-obtained self-supporting Sn/GS films, when were used as anode materials for sodium-ion batteries (SIBs), show promising electrochemical performances. This method not only blazes a new trial for synthesizing Sn/GS nanocomposite films, but also can be extended to develop other free-standing non-noble metal (or alloy) nanoparticles/GS films for wide applications.
Lithium/sulfur batteries in Lithium Metal Polymer (LMP) technology suffer from poor reversibility and important capacity fade. In this paper we studied structural evolutions of Li/S cells with PEO-based (poly(ethylene oxide)) dry polymer electrolyte, by means of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Discharge occurs along with dissolution of the active material into soluble polysulfides in PEO. Diffusion of the sulfide species results in important volume changes of both the electrode and the electrolyte. This eventually leads to collapse of the electrode upon a few cycles, which contributes to the poor cyclability of the battery. In order to prevent this phenomenon, the mechanical strength of the cathode was enhanced by adding poly(vinylidene fluoride) (PVDF) in its composition. However, although PVDF helps maintaining the electrode's structure, it could not completely solve the cyclability issue.
One of the challenges to the sustainability of the Solar Home System (SHS) electrification program in South Africa is equipment theft. In response to this, communities susceptible to solar panel theft resort to mounting their panels flat on the ground so they can be looked after during the day and taken indoors at night for safe keeping. Other households use their security lights to illuminate their environment and provide security for pole and roof mounted solar panels at night. These actions have consequential effects on the performance of the SHS. Several studies have detected resentment from households regarding the low power quality from these systems. Most scientific contributions on the issue of low power from SHS have focused on the challenges based on the technical designs of the systems. The power losses due to the usage pattern of the system has not received much attention. This study therefore reports on the technical losses as a result of the deviation from the designed and installed specification of the system by the users in order to protect their systems. It also investigates the linkage between the technical and economic losses which affects the sustainability of SHS program. A case study was performed in Thlatlaganya village within Limpopo province in South Africa. Technical analysis using PVSYST solar software revealed that the energy output and performance of the battery is compromised as a result of these practices. Economic analysis indicates that the battery life and the economics of owning and operating SHS are affected negatively. The study recommends solutions to mitigate these losses, and proposes a cost effective way of optimizing the operation of SHS using a Bench-Rack system for mounting solar panels.
An amorphous carbon doped with sulfur to be used as anode material for lithium ion batteries is prepared by heat-treatment of a mixture of polyacrylonitrile (PAN) and sulfuric acid. With X-ray photoelectron spectroscopy (XPS), elemental analysis, X-ray powder diffraction (XRD), scanning electron microscopy, and electrochemical capacity measurements effects of sulfur on properties of the carbon anode are investigated. The added sulfur favorably increases the charge capacity in close correlation with an increase of the size of graphite crystallites, L c, the interlayer distance, d 002, and the number of micropores, and the doping of sulfur in the state of CSC. On the other hand, it also causes detrimental changes, for example the formation of amine-group nitrogen, sulfate/sulfonate deposits, and macropores. Nevertheless, as a result, both reversible and irreversible capacities are enhanced. This clearly shows, that added heteroatoms may have opposite influences, good and bad, on electrochemical performance of carbonaceous anode materials. Approaches towards suppressing the unfavorable ones in the application in lithium ion batteries are discussed.
Graphene materials have emerged as a promising alternative for electrodes in vanadium redox flow batteries due to their unique properties. However, its practical application in such large scale energy storage systems still needs further developments on low-cost and scalable processes for graphene production. The preparation of graphenes through the graphite oxide route, followed by thermal reduction, is an interesting option because it offers the possibility to obtain large quantities of solid products which can be directly used in the battery. Here we report on the advantages of applying the thermal reduction directly to the graphite oxide (which also produces exfoliation) instead of to the graphene oxide to produce graphenes suitable as positive electrodes in vanadium redox flow batteries. The results show that, apart from being a more simple procedure, the graphene thus obtained exhibits a better performance, mainly in terms of a lower overpotential and a faster electron transfer rate of the vanadium redox processes. These results are attributed to an enhanced restoration of the 2D graphitic structure in the platelets, leading to a higher electrical conductivity of the material, and also to the presence of a larger amount of reactive edges.
An aluminum current collector was treated by simple reacting an aluminum foil with a solution containing three acids, and the physical effect of this modification on surface of current collector was investigated through scanning electron microscopy (SEM) and contact angle test. Charge/discharge cycling test and electrochemical impedance spectroscopy were used for investigating the role of the treated-Al collector in LiNi0.8Co0.15Al0.05O2 cathode electrode. SEM images show that the surface of the collector is roughened by this method. Also, measurements of the contact angle indicate that the tendency of the modified-foil surface to disperse the solvent is greater than the pristine foil surface. Electrochemical impedance spectroscopy reveals the role of rough surface of the collector on the SEI layer resistance and charge-transfer process. The capacity stability of the modified-collector cathode is far more than the pristine-foil cathode during cycling test. Improved electrochemical results can be attributed to an increase in the surface roughness of the collector and a larger surface area, which allows the binder to stick the active material to the surface from more sites and the separation of active materials from the electrode during the cycling process is greatly reduced.
Fe and N dual-doped mesoporous carbon catalyst demonstrated superior catalytic activity than Pt catalyst for both oxygen reduction and oxidation reactions in alkaline electrolyte. The catalyst was synthesized through a novel simple sublimation and capillary assisted nanocasting method. Using the method, multiple transition metal and nitrogen dual-doped mesoporous carbon electrocatalysts were also successfully made. It was believed that the excellent catalytic activity was resulted from the synergistic effects of highly active metal-nitrogen species, mesoporous structure, large interfacial surface and excellent conductivity. The present synthetic strategy offers a new insight into preparation of heteroatom-doped electrocatalysts with promising applications in metal-air batteries, fuel cells, and supercapacitors as well.
Urban electrification with renewables is a crucial strategy for achieving low-carbon and climate-resilient communities. Given the different types of power customers (e.g., residential, commercial and industrial), this work develops a systematic and straightforward framework for the optimal planning of urban solar/wind/biomass (/natural gas) systems at neighbourhood scale using the actual real-time hourly electric loads. In achieving this objective, we defined three power scenarios (i) 100% natural gas; (ii) natural gas and renewables; (iii) 100% renewables (e.g., solar/wind/biomass) and identified the hybrid systems with the least NPC for each of the three power scenarios. Our results indicate that providing per kilowatt-hour renewable electricity to the industrial sector (0.385 USD/kWh) costs 4% less than the commercial (0.399 USD/kWh) and about 5% less than the residential sector (0.418 USD/kWh) at neighbourhood scales. The more significant cost of electricity (COE) of the residential system is primarily due to the greater batteries to solar PV fractions. Also, COE of solar/wind/biomass plant showed to be three times less than the equivalent solar/wind power system. Likewise, by integrating a low-emission natural gas (NG) generator to the hybrid solar/wind/biomass plant, the system's COE reduced by 30% while resulting in close to three order-of-magnitude higher annual greenhouse gas (GHG) emissions. To address the model accuracy concerning the uncertainty and variations associated with input variables, we further conducted the sensitivity analysis of the systems' COE address the model accuracy concerning the uncertainty and variations associated with input variables by changes in the discount rate and capital cost of the PV panels and batteries. As a result, systems’ COE was detected to be more sensitive to the capital cost of batteries than solar panels. This study can help decision-makers in developing more effective policies and mechanisms to support the urban hybrid renewable energy systems.
Researchers from Cambridge University's engineering department have developed photovoltaic devices that, when doped with single-wall carbon nanotubes (SWNTs), perform better than undoped devices.
We report the synthesis, characterization and battery performance of a novel Mn3O4/graphene composite based on graphene platelets and also an Mn3O4/reduced-graphene-oxide composite for comparison. The electrodes were cast from aqueous dispersions in which lithium carboxymethyl cellulose was used as a binder thus enabling an aqueous based process for anode fabrication. The Mn3O4/graphene-platelet and the Mn3O4/reduced-graphene-oxide composites anode system possess high gravimetric capacities (∼700mAhg−1) and excellent cycling stability (>100 cycles).
A pouch-type flexible thin-film lithium-ion battery is fabricated by sequential screen-printing (wet) processes to produce consecutive layers of a current collector, positive and negative electrodes, and a gel polymer electrolyte. Optimum conditions of each process are determined by adjusting the paste or slurry compositions to achieve lower surface resistance of each layer (current collector and electrodes) and higher ionic conductivity of the gel polymer electrolyte. The fabricated flexible thin-film lithium-ion battery (5.5×5.5cm2, 325μm thick) shows superior electrochemical performance, including an energy density of 292.3WhL−1 based on electrode size (4.0×4.0cm2), an initial discharge capacity of 2.5mAhcm−2 per electrode area, and capacity retention ratio of over 68% at the 50th cycle. To further improve the battery performance, the wet processes are modified by adopting hybrid (dry-wet) processes, which mainly consist of the formation of metallic current collector layers (Al and Cu) using a thermal evaporator and another optimized gel polymer electrolyte, to achieve an energy density of 332.8WhL−1 and capacity retention ratio of 84% at the 50th cycle. Cell flexibility is also confirmed by stable open circuit voltages after the system is subjected to several hundred iterations of bending, stretching, and even folding. There is the possibility that the suggested wet and dry-wet processes can be expanded to a high-speed mass-production roll-to-roll process.
Mesoporous MnO2 with uniform nanorod morphology and mesoporous β-MnO2 were prepared using SBA-15 and KIT-6 as the templates, respectively. XRD, nitrogen adsorption analysis, SEM, TEM and EDX techniques were used for the structural characterization. The electrochemical properties of the MnO2 samples were studied using alkaline Zn/MnO2 batteries in a 9M KOH electrolyte solution. Compared to the commercial electrolytic manganese dioxide (EMD), the discharge capacity of the mesoporous MnO2 nanorods increased by 74.98%, 119.74% and 146.19% at constant currents of 50, 250 and 500mAg−1, respectively, while the discharge capacity of the mesoporous β-MnO2 increased by 63.58%, 95.14% and 100.23%.
In this work we report an investigation about the influence of the salt concentration on the electrolyte 1-Butyl-1-methylpyrrolidinium tetrafluoroborate (Pyr14BF4) in propylene carbonate (PC) on the electrochemical behaviour of composite electrodes containing poly(2,2,6,6-tetramethylpiperidinyl-N-oxymethacrylate) (PTMA) as the active material. The results of this study show that the salt concentration within the electrolyte has a strong influence on the behaviour of PTMA-based electrodes. The use of concentrated electrolytes displaying a good compromise between conductivities and viscosities appears very favourable for the optimization of the capacity and the reduction of the self-discharge of PTMA electrodes.
Li4Ti5O12 nanorods have been successfully synthesized via hydrothermal method using TiO2–B as titanium source and template. Such Li4Ti5O12 nanorods with sizes of 100–200 nm in diameter and 1–2 μm in length can be observed. The Li4Ti5O12 nanorods exhibit high discharge capacity of about 101.1 mAh g−1 after 1000 cycles at 20C for the lithium ion battery anode. The Li4Ti5O12 nanorods also show excellent sodium storage performance, which have a reversible capacity of approximately 131.6 mAh g−1 after 100 cycles at 0.1C. Based on the electrochemical performance, it is suggested that Li4Ti5O12 nanorods have a great potential for lithium and sodium ion battery that are available as large-scale storage devices for applications such as automotive and stationary energy storage.
Sulfolane (tetramethylene sulfone, SL) is known for leading to Li-ion electrolytes with high anodic stability. However, the operation of graphite electrodes in alternative electrolytes is usually challenging, especially when ethylene carbonate (EC) is not used as co-solvent. Thus, we study here the influence of the lithium salt on the physico-chemical and electrochemical properties of EC-free SL-based electrolytes and on the performance of graphite electrodes based on carboxymethyl cellulose (CMC). SL mixed with dimethyl carbonate (DMC) leads to electrolytes as conductive as state-of-the-art alkyl carbonate-based electrolytes with wide electrochemical stability windows. The compatibility with graphite electrodes depends on the Li salt used and, even though cycling is possible with most salts, lithium difluoro-oxalato borate (LiDFOB) is especially interesting for graphite operation. LiDFOB electrolytes are conductive at room temperature (ca. 6 mS cm−1) with an anodic stability slightly below 5 V vs. Li/Li+ on particulate carbon black electrodes. In addition, it allows cycling graphite electrodes with steady capacity and high coulombic efficiency without any additive. The testing of graphite electrodes in half-cells is, however, problematic with SL:DMC mixtures and, by switching the Li metal counter electrode for LiFePO4, the graphite electrode achieves better practical performance in terms of rate capability.
In the process of Li+ intercalation–deintercalation, electron removal is accompanied simultaneously. Oxygen was found to compensate electron removal both in theoretical calculations and practical experiments. Chlorine addition to LiNi0.7Co0.3O2 was expected to exchange electrons in that Cl− was easier to lose electrons than O2−. LiNi0.7Co0.3O2−x Cl x was identified as a pure hexagonal lattice of α-NaFeO2 type by X-ray diffraction. X-ray photoelectron spectroscopy was used to analyze the influence of chlorine substitution on the oxidation state of transition-metal ions. Charge–discharge experiments and cyclic voltammetry confirmed that chlorine addition was an effective way to improve reversible capacity and structural stability in cycles.
Publisher Summary This chapter discusses the processing properties and applications of micro-/nano-fibers by electrospinning technology. Electrospinning is a fiber-spinning technology used to produce long, three-dimensional, ultrafine fibers with diameters in the range of a few nanometers to a few microns (more typically 100 nm to 1 micron) and lengths up to kilometers. When used in products, the unique properties of nano-fibers are utilized, such as extraordinarily high surface area per unit mass, very high porosity, tunable pore size, tunable surface properties, layer thinness, high permeability, low basic weight, ability to retain electrostatic charges and cost effectiveness, among others. These fibers are used not only in clothing but also in hygienic products, in medical and automotive applications, in geo-textiles and in other applications. Traditional methods for polymer fiber production include melt spinning, dry spinning, wet spinning and gel-state spinning. These methods rely on mechanical forces to produce fibers by extruding extruding a polymer melt or solution through a spinneret and subsequently drawing the resulting filaments as they solidify or coagulate.
Inspired by the high performance obtained previously with TiSnSb, NbSnSb was investigated as negative electrode in Li-ion batterie. After its synthesis by ball milling and full characterization by XRD and Mössbauer spectroscopy, electrochemical tests at various current rates and temperatures were realized. The electrochemical performance at 25 and 60 °C turned out to be very promising, being better than those previously obtained with the parent electrode material TiSnSb with a specific capacity higher than 450 mAh/g maintained during more than 400 cycles at 60 °C. Preliminary tests in full cells confirmed that this anode material could be considered as a potential material for future Li-ion batteries.
We have developed innovative multilayer composite grids as engineered materials, which are produced in the form of grid strip in a single, highly efficient, multistage electrodeposition process. In the present paper, we are reporting, how the individual requirements for grid properties can be satisfied and optimised individually and then combined simultaneously to an overall optimum in this new family of composite grid materials. The multilayer composite materials are composed of different layers of different structures and properties, which can provide a combination of different functional properties to satisfy a more demanding total specification of mechanical behaviour, electrical performance, corrosion resistance and cycling behaviour. The paper deals with the improvement of these properties in detail and with the overall simultaneous engineering of the grid material.
The present study approaches the issue of school achievement at gymnasium and high school levels.The participants are 366 gymnasium and high school students (medium age 16.1 years, SD 1.80) who were tested with a complex battery made of eight intelligence tests, together with Big Five personality questionnaire and Holland's Self-Directed Search (SDS). According to the model of Holland's structure of interests, it is expected that the realistic type should provide the biggest ratio of underachieved people while the social type the biggest ratio of overachieved people. The research confirms these hypotheses and opens several new directions of investigating school achievement.
Multi-walled carbon nanotube (MWCNT)/polyaniline (PANI)/MnO2 (MPM) ternary coaxial structures are fabricated as supercapacitor electrodes via a simple wet chemical method. The electrostatic interaction between negative poly(4-styrenesulfonic acid) (PSS) molecules and positive Mn2+ ions causes the generation of MnO2 nanostructures on MWCNT surfaces while the introduction of PANI layers with appropriate thickness on MWCNT surfaces facilitates the formation of MWCNT/PANI/MnO2 ternary coaxial structures. The thickness of PANI coatings is controlled by tuning the aniline/MWCNT ratio. The effect of PANI thickness on the subsequent MnO2 nanoflakes attachment onto MWCNTs, and the MPM structures is investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and field-emission scanning electron microscopy (FESEM). The results suggest that appropriate thickness of PANI layers is important for building MPM ternary coaxial structures without the agglomeration of MnO2 nanoflakes. The MPM ternary coaxial structures provide large interaction area between the MnO2 nanoflakes and electrolyte, and improve the electrochemical utilization of the hydrous MnO2, and decrease the contact resistance between MnO2 and PANI layer coated MWCNTs, leading to intriguing electrochemical properties for the applications in supercapacitors such as a specific capacitance of 330Fg−1 and good cycle stability.