batterydata/paper-abstracts huggingface dataset:
Structural dielectric capacitors (SDCs) are load-bearing multifunctional materials that uniquely combine high electrical energy storage capacity with high mechanical properties. The development of electrically conductive carbon fibre reinforced polymer (CFRP)-based electrodes is a promising approach to create high strength SDCs, although challenges remain due to the low conductivity of epoxy matrix of CFRP. Carbon nanotubes and graphene nanoplatelets are commonly used as conductive fillers to produce electrically conductive polymers. However, the electrical conductivity of composites is restricted by the maximum filler content, which is essential to retain composite structures. In this work, gold nanoparticles (AuNPs) with high electrical conductivity were added in different weight fractions (up to 1 wt%) into the epoxy matrix of CFRP electrodes used in graphene oxide-bearing SDCs (GO/SDCs). The electrical conductivity of AuNP-modified CFRP electrodes was 15–250% higher than the unmodified CFRP electrode, depending on the concentration of nanoparticles. As a result, both specific capacitance and energy storage density of AuNPs-modified GO/SDCs were higher (up to ~170% and ~50%, respectively) than the unmodified GO/SDC. Furthermore, AuNP-modified GO/SDCs had higher tensile and interlaminar shear properties. This research provides new insights into improving both the electrical and mechanical properties of SDCs using AuNPs.
Lithium metal is considered as an ideal anode material for lithium-ion batteries, because of its highest theoretical specific capacity, energy density, low reduction potential, and lightweight. However, its practical application is being hindered by factors such as the presence of uncontrolled interfacial reactions with liquid electrolytes, unstable solid electrolyte interphase (SEI), dendrite formation due to inhomogeneous lithium-deposition and poor cycle life. Herein, Lithium ion conducting composite film comprising of cubic garnet (Li7La2.75Ca0.25Zr1.75Nb0.25O12) (LLCZN), polyvinylidene fluoride (PVDF) and lithium perchlorate (LiClO4) salt is prepared by electrospinning. The composite film induces inorganic-rich solid electrolyte interphase which is mechanically stable to suppress the formation of lithium dendrites. The Li‖Cu@LLCZN/PVDF(84:16)LiClO4 cell exhibits negligible polarization compared to a bare copper one (Li‖Cu) performed in 1 M LiPF6 ethylene carbonate (EC) diethyl carbonate (DEC) (1:1 v/v ratio) electrolyte at a current density of 0.2 mA cm−2. Moreover, the anode free full cell configuration (Cu@LLCZN/PVDF‖NMC) demonstrates improved capacity retention of 58.66% and average coulombic efficiency of 97.6% after 30th cycles. The as-synthesized composite film induces inorganic rich (LiF and LiCl) SEI and gives required mechanical strength to suppress the lithium dendrite formation. These features endow the Cu anode with stable interface chemistry which is essential to the realization of anode-free lithium metal batteries.
By using carbon nanotube (CNT), Pb(NO3)2/CNT is fabricated by a solution method and investigated for the first time as probable anode materials for sodium-ion batteries. For comparison, pristine Pb(NO3)2 and Pb(NO3)2/carbon black (CB) are also prepared by the same solution method. Electrochemical results show that Pb(NO3)2/CNT can deliver an initial charge capacity of 285.7mAhg−1, which is much higher than the pristine Pb(NO3)2 (203.8mAhg−1) and Pb(NO3)2/CB (252.1mAhg−1). After 50 cycles, Pb(NO3)2/CNT still maintains a sodium storage capacity of 112.9mAhg−1. Furthermore, it also shows outstanding rate property compared with other two samples. All the enhanced results can be attributed to the introduction of crosslinked CNTs in the composite, which provide good electronic conductive pathways interconnecting Pb(NO3)2 particles and maintain the whole nano-micro structure upon repeated cycles. The reaction mechanism of Pb(NO3)2 with Na is studied by various in-situ and ex-situ techniques. It can be found that Pb(NO3)2/CNT irreversibly decomposes into Pb, NaNO3, NaN3, and Na2O, and then the resulting metal Pb will further react with Na to form NaxPb alloys during the initial discharge process. In contrast, the charge process is mainly associated with the de-alloying reaction of NaxPb to the formation of Pb.
TiO2 hollow spheres are fabricated by a sol–gel process using carbon spheres as template. The diameter and the shell thickness of the TiO2 hollow spheres are about 400–600nm and 60–80nm, respectively. The electrochemical properties of the hollow spheres are investigated by galvanostatic cycling and cyclic voltammetry (CV) measurements. The initial discharge capacity reaches 291.2mAhg−1 at a current density of 60mAg−1. The average discharge capacity loss is about 1.72mAhg−1 per cycle from the 2nd to the 40th cycles and the coulombic efficiency is approximately 98% after 40 cycles, indicating excellent cycling stability and reversibility.
The paper presents an in-depth analysis of a novel scheme for the sustainable mobility, based on electric vehicles, photovoltaic energy and electric energy storage systems. The work aims to analyse such innovative system, putting in evidence its advantages in comparison to a conventional one, based on the grid-to-vehicle technology. The study also provides interesting guidelines for potential users and system designers. Two case studies are presented: i) the taxi fleet of the city centre of Naples and ii) the cargo vans of the city of Salerno; both towns are in Southern Italy. For each case, the hourly power consumption of the vehicles was evaluated, as a function of the daily trip length. An accurate procedure was implemented to select the sites suitable for the installation of the charging stations, including a photovoltaic field and an electric storage system. A comparison was also performed between two different electric storage technologies: lead-acid and lithium-ion battery. The case studies were analysed by means of a detailed dynamic simulation model, developed in TRNSYS. A sensitivity analysis was also performed, to evaluate how different values of the most important design and operating parameters affect the system overall performance. It was found that the results are mostly affected by solar field area, capacity of the energy storage system and investment cost. The comparison between the two selected storage technologies did not exhibit significant differences. For both the cases investigated, it was found that, during the summer, solar energy covers an important amount of the total energy demand. On the contrary, in winter the amount of energy provided by the public electric grid was high. From an economic point of view, assuming a lithium-ion battery capital cost equal to 90 €/kWh, acceptable pay-back periods (about 6 years) were obtained, for both the applications considered.
The virtual test bed (VTB) computation environment provides an easy-to-use way for electric system modeling and simulation. Resistive companion (RC) modeling of batteries in VTB is presented in the paper. Native RC battery modeling approach and the one using current controlled voltage source (CCVS) interface are presented and compared through two battery models with different degrees of complexity. The RC battery models are validated by comparing VTB simulation data to those calculated directly through stand-alone Fortran codes. It is concluded that using CCVS interface is currently the first choice in modeling batteries in VTB. Simulations using the RC battery models in VTB are also presented and analyzed. It is shown that RC modeling provides a powerful way for the simulation of battery systems in VTB.
Spherical Li3V2(PO4)3/C(LVP/C) composites were synthesized by sol–gel method using diethylene glycol as the spheroidizing medium and glucose as the carbon source. The crystal structure, morphology, the lithium diffusion behavior and high rates capacities were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and electrochemical methods. Results indicated that the sphere-like LVP/C sample prepared with 10wt% glucose has a uniform carbon layer about 10nm on the surfaces, and presented a high discharge capacity of 131.8, 126.5, 102.4, 82.8mAhg−1 at 0.1, 2, 10, 20C between 3.0 and 4.3V with no obvious capacity fading during 200 cycles at the rate of 2C. While in the voltage region of 3.0–4.8V, it owned the largest reversible capacity of 169.4, 139.8, 121.7mAhg−1 at 0.5, 1, 5C, respectively. Its capacity retained 79.9% after 200 cycles at 2C, and the apparent Li-ion diffusion coefficient was calculated to be 3.37×10−9 cm2 s−1.
The successful operation of stationary lead-acid batteries of the VRLA/AGM type at cold and extremely cold temperatures is a precondition for the further expansion of their application envelope. Application oriented tests and investigations show a surprisingly robust behavior of such batteries under temperature conditions as low as −30°C. The results obtained in these tests are presented and show data concerning available discharge energy at low temperatures, the behavior during charge and discharge cycles, the effect of freeze and thaw cycles and structural aspects of the “frozen” electrolyte at these temperatures.
Solid solution material of 0.5Li2MnO3·0.5LiNi0.33Co0.33Mn0.33O2 (alternatively Li[Li0.2Mn0.54Ni0.13Co0.13]O2) was synthesized by a fast co-precipitation method which takes sulfates with high solubility as the transition metal sources of mixed hydroxide precursor. The optimal synthetic conditions were determined through the design of orthogonal experiments. The properties of samples synthesized under the best conditions were investigated in detail. The XRD pattern of 0.5Li2MnO3·0.5LiNi0.33Co0.33Mn0.33O2 revealed a well ordered hexagonal layered structure with the evident feature of super lattice caused by Li2MnO3. FESEM images showed that the powders possess small and unagglomerated particles with size range of 100–300nm. XPS analysis results demonstrated that the valence states of Ni, Co, Mn are +2, +3, and +3.52 respectively. The electrochemical measurements showed that the optimal material delivers initial discharge capacity of 315.3mAhg−1 at 1/20C between 2.0 and 4.8V with good cycle stability after firstly several cycles. CV test proved that the high capacity performance is ascribed to the redox of oxygen or its species at the electrode surface. Rate test showed that 179.5mAhg−1 was obtained at 2C which is considerably high, as far as we concerned.
We tried fabricating a binder-free co-deposited film electrode consisting of SnO2 nanoparticles (nano-SnO2) and acetylene black (AB) particles by an electrophoretic deposition (EPD) method. By cathodically depositing on a copper foil when employing an acetone bath, the co-deposited film consisting of nano-SnO2 and AB could be fabricated. SEM/EDX indicated that the roughness of the co-deposited film was approximately 1μm and the nano-SnO2 particles and the AB particles were uniformly deposited. The weight percent of the nano-SnO2 in the co-deposited film could be controlled in the range from 87.80 to 93.64wt.%. The galvanostatic charge–discharge tests indicated that the discharge capacity and the charge–discharge efficiency of the co-deposited film (nano-SnO2:AB=93.64:6.36wt.%) at the 1st cycle were 887mAhg−1 and 48.8% at 0.1C, respectively; the discharge capacity after the 50th cycle was 504mAhg−1. It has been considered that the reverse reaction of the conversion reaction would occur during discharging because the discharge capacity at the 1st cycle was higher than the theoretical capacity of SnO2 (783mAhg−1). Thus it has been clarified that the binder-free co-deposited film could operate as a negative electrode for lithium secondary batteries.
Mono Lake sediment slurries incubated with lactate and tellurite [Te(IV)] turned progressively black with time because of the precipitation of elemental tellurium [Te(0)]. An enrichment culture was established from these slurries that demonstrated Te(IV)-dependent growth. The enrichment was purified by picking isolated black colonies from lactate/Te(IV) agar plates, followed by repeated streaking and picking. The isolate, strain MLTeJB, grew in aqueous Te(IV)-medium if provided with a small amount of sterile solid phase material (e.g., agar plug; glass beads). Strain MLTeJB grew at high concentrations of Te(IV) (~8 mM) by oxidizing lactate to acetate plus formate, while reducing Te(IV) to Te(0). Other electron acceptors that were found to sustain growth were tellurate, selenate, selenite, arsenate, nitrate, nitrite, fumarate and oxygen. Notably, growth on arsenate, nitrate, nitrite and fumarate did not result in the accumulation of formate, implying that in these cases lactate was oxidized to acetate plus CO2. Strain MLTeJB is a low G + C Gram positive motile rod with pH, sodium, and temperature growth optima at 8.5–9.0, 0.5–1.5 M, and 40°C, respectively. The epithet Bacillus beveridgei strain MLTeJBT is proposed.
This paper applies multivariable robust control strategies to a proton exchange membrane fuel cell (PEMFC) system. From the system point of view, a PEMFC can be modeled as a two-input-two-output system, where the inputs are air and hydrogen flow rates and the outputs are cell voltage and current. By fixing the output resistance, we aimed to control the cell voltage output by regulating the air and hydrogen flow rates. Due to the nonlinear characteristics of this system, multivariable robust controllers were designed to provide robust performance and to reduce the hydrogen consumption of this system. The study was carried out in three parts. Firstly, the PEMFC system was modeled as multivariable transfer function matrices using identification techniques, with the un-modeled dynamics treated as system uncertainties and disturbances. Secondly, robust control algorithms were utilized to design multivariable H ∞ controllers to deal with system uncertainty and performance requirements. Finally, the designed robust controllers were implemented to control the air and hydrogen flow rates. From the experimental results, multivariable robust control is shown to provide steady output responses and significantly reduce hydrogen consumption.
Co3O4 nanoparticles are grown on nitrogen modified microwave exfoliated graphite oxide (NMEG) with weight ratio controlled from 10% to 70%. Electrochemical performance reveals that the obtained Co3O4/NMEG composite as Li-ion battery anode exhibits improved cycle stability, excellent reversible capacity, high current rate performance, and reduced irreversible capacity loss in the initial cycle compared to pure Co3O4 without graphene or Co3O4 on thermally reduced graphene oxide (tRG-O). The 70%Co3O4/NMEG composite has initial irreversible capacity of 230mAhg−1 (first cycle efficiency of 77%), and 910mAhg−1 of capacity is retained after 100 cycles. The 70%Co3O4/tRG-O delivers a reversible capacity of 750±20mAhg−1, and the irreversible capacity loss during the first cycle is 700±20mAhg−1. Nitrogen functional groups in NMEG, especially pyridinic and pyrrolic N are advantageous for the Co3O4 growth. Furthermore, the N modification is effective in reducing the oxygen content of chemically prepared graphene and hence is good for Co3O4 dispersion and the amelioration of first cycle efficiency, demonstrating the potential of NMEG based composite as high performance Li-ion battery anode materials.
Copolymers of aniline and either 2-aminonaphthalene-4,8-disulfonic acid, or 2-aminonaphthalene-6,8-disulfonic acid, have been electrodeposited at a gold electrode, and studied by the means of in situ surface enhanced resonant Raman spectroelectrochemistry. Characteristic Raman features have been identified, and their dependencies on the electrode potential have been discussed. The nature of Raman band, observed at ca. 1630cm−1 with the red He–Ne laser excitation (632.8nm), is discussed. The intensity of this band grows during a positive potential shift up to a maximum, located at ca. 0.4–0.5V vs. Ag/AgCl, and then decreases with a further potential shift up to 1.0V. Based on this, a possible alternate structure of electrogenerated copolymers has been discussed, which includes a ladder-type phenazin-like molecular unit. The “ortho-coupling” instead or parallel to the usual “para-coupling” has been suggested to proceed during electrocopolymerization of the monomers studied with aniline.
The commercialization of large-scale energy storage systems has renewed the scientific interest on electrode materials for sodium-ion batteries (SIBs). Polyanionic sodium orthosilicates [Na2M(SiO4)] are an interesting group of SIB cathode materials with high redox potentials via a two-electron redox process, and their three-dimensional framework. However, studies on these materials are limited due to difficulties in synthesizing them in stable and electrochemically desirable phase. Exhibiting rich polymorphism, orthosilicates undergo irreversible structural changes during processing and/or cycling. Here, we report a solvothermal process, which yields in situ carbon-coated Na2CoSiO4 with monoclinic structure. Besides physical characterization, we discuss its electrochemical performance in coin-cell configuration vs. Na anode. Na2CoSiO4 exhibits significantly lower polarization (0.15 V) than Na2FeSiO4 and Na2MnSiO4. As polyanionic compounds are poor electronic conductors with sluggish redox kinetics, we observe that these limitations could be overcome in Na2CoSiO4 by incorporating functionalized multi-walled carbon nanotubes (MWCNTs). The Na2CoSiO4/MWCNT composite cathode reversibly delivers 125 mAh g−1 at C/20 rate, almost 50% more than pristine Na2CoSiO4. We also provide insights into the Na+ diffusion and exchange current by applying electrochemical impedance spectroscopy (EIS), revealing that the Na+ diffusion coefficient increases by one order while the exchange current doubles when functionalized MWCNTs are added to Na2CoSiO4.
A highly active Pt/carbon catalyst for polymer electrolyte membrane fuel cells and direct methanol fuel cells was prepared by using porous carbon that was synthesized by a colloidal-crystal templating method. The microstructure of the Pt/porous carbon composites was studied with N2 ad-/desorption isotherms, X-ray diffraction and transmission electron microscopy. In contrast to conventional carbon supports, the porous carbon exhibited an attractive microstructure as a catalyst support, i.e. a large surface area with mono-dispersed three-dimensionally interconnected mesopores (45nm). A large mesopore surface area prompted dispersion of Pt particles, which resulted in a large effective surface area of Pt with a high activity for the oxygen reduction reaction. The porous structure facilitated smooth mass transportation to give rise to high limiting currents.
This study presents discussions on sustainability of Virtual and Remote Laboratories (VRL), and provides challenges toward maintenance of VRLs. Technical and pedagogical issues in extension and sustenance of VRLs are discussed with the experiences of the authors gained in the development of a VRL system, European Remote Radio Laboratory (ERRL) platform. Moreover, the study presents actions to be taken in sustenance plan and expendability of VRL system with the advances in Information and Communication Technologies (ICT) and educational technologies along with the needs of educators and learners in formal education.
Emergency call centers serve people in utmost circumstances; hence they should be highly dependable. Availability and performance are key aspects in call centers. Architectural models, service policies, and redundancies are attributes for defining and evaluating the overall operation of such systems. In this work, we performed the performability evaluation of an important emergency call center located in a large city in Brazil. The results showed that the system’s downtime is considered high, so, we proposed a new architecture to improve the system’s performability. The results obtained in this paper can be used to provide support for decisions on interventions in the emergency call center to improve its performability. It is expected that the models presented in this paper will be useful in a variety of emergency call centers.
The recent boom of GPS (Global Positioning System) as a universal method of location has meant that most people in developed countries have already used this technology sometime in their lives. However, this system suffers from an ever-increasing problem: energy expenditure. GPS receivers have been integrated into increasingly smaller devices such as the latest generation of mobiles, thereby making battery-saving a priority in the use of this technology. This article lays out a series of ideas which, through the use of auxiliary technologies, are able to maximize energy saving. By means of outdoor exit detection, it will be possible to automatically disconnect the GPS while the user stays indoors and later reconnect it on leaving the building.
The commercialization of Na-ion batteries demands the development of technologically feasible and economically viable electrodes, in particular anodes. Herein, we report the facile synthesis of nanostructured FeSn2 by a hydrothermal route and the formulation of composites with different carbonaceous materials like Super P, graphite, and graphene via high-throughput ball-milling. The influence of the carbonaceous matrix on the electrochemical performance of the alloy anode is investigated in half-cell assembly. Amongst, FeSn2-Graphite composite exhibits excellent cycling stability with a reversible capacity of 333 mAh g−1 obtained after 100 cycles at a specific current of 100 mA g−1. The composite also displayed a good rate performance even at high current rates of 1 A g−1 which is a desirable feature for high power applications such as hybrid electric vehicles. The outstanding electrochemical performance of the composite anodes is ascribed to the effective encapsulation of the alloy particles in the carbonaceous matrix, which sustains the volume change and facilitates excellent Na-storage capability.
In this work we investigate the electrode degradation mechanisms in a commercial 2.5 Ah LiFePO4/graphite 26650 cylindrical cell. Aged and fresh electrode samples were prepared by cycling two cells respectively five and 22 k times. Subsequently the cells were disassembled in a glovebox and the electrode samples were prepared for electrochemical testing in a 3-electrode setup, and for characterization with XRD, XPS and low-kV FIB/SEM tomography. A 1 μm thick CEI (cathode electrolyte interface) layer was observed at the electrode/electrolyte interface of the aged LiFePO4 electrode. Relative to the fresh LiFePO4 electrode, the aged electrode exhibited a larger series resistance which indicates the observed degradation layer increases the ionic resistance. In addition, micron-sized agglomerates, probably a mixture of carbonaceous material and decomposition products from the electrolyte, were observed at the electrode/electrolyte interface of the aged graphite electrode. These layers may contribute significantly to the loss of lithium inventory (LLI) in the cell, and to the loss of active material (LAM) in the graphite electrode. Low-voltage FIB/SEM tomography was used to detect local charging effects of graphite particles in the carbon electrode, an effect of poor dissipation of the electric charge to the ground after the sample interaction with the electron beam. The charging effects were primarily observed in the aged electrode and most of the locally charged particles were found to be close to the electrode/electrolyte interface, indicating a poorly percolating graphite network near this interface.