batterydata/paper-abstracts huggingface dataset:
Electrochemical processes at the electrode–electrolyte (body fluid) interface are of ultimate importance for stimulating/sensing electrode function. A high electrode surface area is desirable for safe stimulation through double-layer charging and discharging. Pt and Pt–Ir alloys have been the most common electrode materials. The use of TiN coating as the surface layer on the electrode has found increasing interest because of its metal-like conductivity, excellent mechanical and chemical properties, and the fact that it can be deposited with a high surface area. In this work, electrochemical impedance spectroscopy (EIS), which is a sensitive and non-destructive technique and widely used for characterization of electrical properties of electrode–electrolyte interfaces, was applied to investigate pure Pt and Ti, and TiN coated electrodes exposed to a phosphate-buffered-saline (PBS) solution. Platinized Pt and Ti were also studied for comparison. The capacitance value of the electrodes in PBS was obtained through quantitative analysis of the EIS spectra. The results reveal that the capacitance of the TiN coated electrodes with a rough surface is several hundreds times higher than that of a smooth Pt surface. Platinization of Ti can also increase the capacitance to the same extent as platina. EIS has been shown to be a powerful technique for characterization of stimulating/sensing electrodes.
Utilizing the solvothermal synthesis technique, lithium intercalated tungsten disulfide Li x WS2 with x >1 was obtained, which was allowed to react with water to the formation of single-molecule-layer suspension of tungsten disulfide. The layered nanocomposites PEG, PEO/WS2, intercalating poly(ethylene glycol) (PEG, MW≈1×103, 6×103, 1×104) and poly(ethylene oxide) (PEO, MW≈3×105) into the tungsten disulfide host galleries, were prepared using the improved exfoliation–adsorption technique. It was revealed that the intercalated polymers within the host galleries are in a double-layer arrangement with an interlayer expansion of about 9Å. Despite high conductivity of the host material, those of the PEG, PEO/WS2 nanocomposites were found to be high in the order of 1×10−2 to 10−3 Scm−1 at ambient temperature, resulted from the guest–host charge transfers.
Single-phase, chemically pure vanadium pentoxide (V2O5) powders are prepared by co-precipitation and further calcination at 300°C. The materials obtained are agglomerated in sub-micron particles, and BET analysis shows that the as-prepared V2O5 powders have a high specific surface-area of 41m2 g−1. V2O5 shows the highest capacitance in 2M KCl electrolyte when compared with other electrolytes such as 2M NaCl and 2M LiCl. It yields a maximum specific capacitance of 262Fg−1. The higher specific surface-area may be the reason for the high capacitance compared with previously published results.
The interaction of vanadium ions (V2+, V3+, VO2+ and VO2 +) with counter ions in the condensed-phase vanadium redox flow battery (VRFB) system is investigated using force-field based molecular dynamics (MD), coupled with well-tempered metadynamics (WT-MetaD). In the conventional VRFB electrolyte, (i) bisulphate ions are found relatively less stable in the first solvation shell of vanadium ions than in the bulk, and (ii) the free energy of sulphate ions in the first solvation shell of vanadium ions is marginally lower than that in the bulk. Thus, significant proportion of vanadium ions in the conventional VRFB will have an undisturbed water coordination sphere. The presence of additives like hydrochloric acid and phosphate salts introduces chloride and dihydrogen phosphate ions into the electrolyte. These counter ions are found to be significantly more stable in the first solvation shell of vanadium ions, thereby modifying their local solvation structure by replacing water molecules. The activation free energy barriers for the diffusion of all counter ions into the first solvation shell of vanadium ions can be overcome at room temperature. We believe that the MD + WT-MetaD tool, as presented here, can be used to screen and select potential additives for enhancing the solubility of vanadium ions in VRFB.
Synaesthesia is a neurodevelopmental condition in which a sensation in one modality triggers a perception in a second modality. Autism (shorthand for Autism Spectrum Conditions) is a neurodevelopmental condition involving social-communication disability alongside resistance to change and unusually narrow interests or activities. Whilst on the surface they appear distinct, they have been suggested to share common atypical neural connectivity.
Slow gas diffusion limits mass transfer and is detrimental in various device applications, such as fuel cells, batteries, membrane engineering, and catalysis. In fuel cells, the gas diffusion coefficient, called the diffusivity, correlates with the concentration polarization (CP) energy loss and such important parameters associated with electrode materials as porosity and tortuosity. Although three dimensional (3D) diffusion and 3D diffusivity have been investigated via theoretical computing and modeling, a technique allowing for the direct measurement of 3D diffusivity in fuel cells is still lacking. In this report, an electrochemical cell is proposed for the measurement of 3D diffusivity in fuel cells. This device enables one to measure simultaneously diffusivity in three electrode directions. A 3D diffusivity measurement leads directly to a precise evaluation of the 3D concentration polarization, the 3D limiting current density (LCD), the 3D electrode porosity and the 3D electrode tortuosity. Based on the diffusivity measurement in three electrode directions, a rational selection of the optimum electrode operation direction can be realized.
O3/P2-layered oxides, especially O3–NaCrO2, have been widely investigated as cathode materials for sodium-ion batteries due to their high stability and flexible synthesis procedure, but their low electron conductivity, the toxicity of Cr(VI) and cation disorder limit their applications. Here, we present O3–Na(Cr0.8Mn0.2)O2 as a promising cathode, which has a higher average storage voltage than O3–NaCrO2 and a practical useable capacity of ca. 100 mAh/g. The low volume change (~0.90%), lack of toxic Cr6+ formation and cation ordering in the optimized O3–Na(Cr,Mn)O2 structure ensure a potentially long cycle life. In situ XRD was used to monitor the phase formation at high temperature and to unveil the working mechanism of the O3–Na(Cr,Mn)O2 electrode during cycling. XAS and DFT investigations revealed variations in the local structure and the sequence of charge transfer of the transition metal during cycling. This work sheds light on the sodium storage mechanism of O3-layered oxides from micro- and electronic-structure points of view and reveals the role of transition metals in the working mechanism and performance.
A wireless sensor network (WSN) is a large collection of sensor nodes with limited power supply, constrained memory capacity, processing capability, and available bandwidth. The main problem in event gathering in wireless sensor networks is the formation of energy-holes or hot spots near the sink. Due to the restricted communication range and high network density, events forwarding in sensor networks is very challenging, and require multi-hop data forwarding. Improving network lifetime and network reliability are the main factors to consider in the research associated with WSN. In static wireless sensor networks, sensors nodes close to the sink node run out of energy much faster than nodes in other parts of the monitored area. The nodes near the sink are more likely to use up their energy because they have to forward all the traffic generated by the nodes farther away to the sink. The uneven energy consumption results in network partitioning and limit the network lifetime. To this end, we propose an on-demand and multipath routing algorithm that utilizes the behavior of real termites on hill building termed Termite-hill which support sink mobility. The main objective of our proposed algorithm is to efficiently relay all the traffic destined for the sink, and also balance the network energy. The performance of our proposed algorithm was tested on static, dynamic and mobile sink scenarios with varying speed, and compared with other state-of-the-art routing algorithms in WSN. The results of our extensive experiments on Routing Modeling Application Simulation Environment (RMASE) demonstrated that our proposed routing algorithm was able to balance the network traffic load, and prolong the network lifetime.
Poly(aniline-co-p-aminophenol) (copolymer) film was used as a sensor to determine the presence of catechol, taking advantage of the ability of the film to effectively catalyze the oxidation of catechol. The copolymer served as an electron transfer mediator between the electrode surface and catechol in the solution. The response current of the catechol sensor depended on the applied potential, pH and temperature at a given concentration of catechol. At optimum conditions, the catechol sensor displayed an excellent electrocatalytic response to the detection of catechol in a concentration range from 5 to 500μM with a detection limit of 0.8μM. The effects of selected organic compounds on the response of the catechol sensor were studied. Together, these findings show that the catechol sensor exhibits a better selectivity towards interfering species and a better operational and storage stability.
Developing energy storage equipments that can work at very high charge–discharge rate is crucial, but highly challenging for more efficient use of energy. From the perspective of chemistry, high-rate property of Li-ion batteries can only be achieved by significantly improving the kinetics of lithium ions and electrons in electrode. Here, we for the first time report on a simple method to resolve kinetics problems of ultrafast charging–discharging Li-ion batteries by fabrication of layered LiMO2 (M = Mn, Co, Ni) hexagonal sheet exposing with facets {101}. The synthetic procedure of hexagonal sheets is proceeded via a simple PVP-assisted co-precipitation, which is followed by a heat treatment. All hexagonal sheets LiMn x Co y Ni z O2 were demonstrated to deliver a superior excellent rate capability and outstanding cycle stability at high current density of 3000 mA g−1 and under a high cutoff voltage of 4.4 V. The discharge capacity for the composition LiMn0.075Co0.775Ni0.15O2 at an ultrahigh charge–discharge rate of 10,000 mA g−1 is almost as large as that for LiMn2O4 and commercial LiFePO4 at low rate of 1C. The methodology reported here to resolve the kinetic problems of lithium ions and electrons in electrodes may have many implications that would help scientists to find more high-rate lithium-ion batteries for powering electric vehicles and other applications.
As an attempt to depart from conventional transient liquid phase sintering practice, solid state vacuum sintering was studied in loose powder and in hot quasi-isostatically forged samples composed of commercial inert gas atomized (CIGA) or high purity Al powder. The high purity Al powder was generated by a gas atomization reaction synthesis (GARS) technique that results in spherical powder with a far thinner surface oxide. After vacuum sintering at 525 °C for up to 100 h, SEM results showed that the GARS Al powder achieved significantly advanced sintering stages, compared to the CIGA Al powder. Tensile results from the forged samples also showed that although its ultimate tensile strength is lower, 95 vs. 147 MPa, the ductility of the GARS pure Al sample is higher than the CIGA Al sample. Forging also consolidated a model powder-based composite system composed of an Al matrix reinforced with quasi-crystalline Al–Cu–Fe powders, where the same powder synthesis methods were compared. Auger surface analysis detected evidence of increased matrix/reinforcement interfacial bonding in the composite sample made from GARS powder by alloy interdiffusion layer measurements, consistent with earlier tensile property measurements. The overall results indicated the significant potential of using Al powders produced with a thin, high purity surface oxide for simplifying current Al powder consolidation processing methods.
We introduce the Friends and Family study, a longitudinal living laboratory in a residential community. In this study, we employ a ubiquitous computing approach, Social Functional Mechanism-design and Relationship Imaging, or Social fMRI, that combines extremely rich data collection with the ability to conduct targeted experimental interventions with study populations. We present our mobile-phone-based social and behavioral sensing system, deployed in the wild for over 15 months. Finally, we present three investigations performed during the study, looking into the connection between individuals’ social behavior and their financial status, network effects in decision making, and a novel intervention aimed at increasing physical activity in the subject population. Results demonstrate the value of social factors for choice, motivation, and adherence, and enable quantifying the contribution of different incentive mechanisms.
In this paper, a network-independent pattern has been used to design a hybrid (PV/wind/Batt) system with high reliability and minimum production total costs over the life of the system. In such systems, optimum sizing is the main issue for having a cost-effective system. In this regard, studies the performance of different PSO (particle swarm optimization algorithm) variants to determine the optimum sizing of hybrid (PV/wind/Batt) system, namely, PSO, modified PSO (MPSO), PSO based on repulsion factor (PSO-RF), PSO with constriction factor (PSO-CF), and PSO with adaptive inertia weight (PSO-W). The system's components optimal size has been studied under various performance conditions using real-time information and meteorological data of one of three atypical regions located in Iran. Simulation results indicate that PSO-CF produces more promising results than the other variants, tabu search (TS), simulated annealing (SA) and harmony search (HS) algorithms in terms of mean (Mean), standard deviation (Std.), worst (Worst) and best (Best) the total annual cost (TAC).
The use of electrospun nanofibre (NF) membrane of SnO2 toward the efficiency enhancement in dye sensitized solar cells (DSSCs) with a triple layered, AlCl3 treated SnO2-based photoanode is presented. The performance of DSSCs fabricated with SnO2 nanoparticle (NP)-based photoanode is compared with that of DSSCs made with a novel triple layered SnO2 photoanode of configuration FTO/NP/NF/NP. Thickness of the NF membrane is optimized to achieve the highest solar cell performance. Solar cells made with single layer SnO2 NP photoanode sensitized either by Eosin-Y dye or Indoline dye showed efficiencies of 0.3% and 2.02%, respectively, under the irradiance of 100 mW cm−2 (AM 1.5), while the corresponding devices with AlCl3-treated, triple layered photoanode showed efficiencies of 1.55 and 2.77%, respectively, under the same illumination. Accordingly, more than five-fold enhancement in overall efficiency is achieved in DSSCs by using this novel SnO2-based photoanode with the optimized thickness of the SnO2 nanofibre membrane and sensitized with Eosin-Y dye. Scanning electron microscopic studies revealed that the SnO2 nanofibre membrane consists of an interconnected network-like structure formed by the SnO2 nanofibres. Electrochemical impedance spectroscopy measurements on DSSCs made with these two types of photoanodes reveals that the series resistance of the DSSC made with the novel NP/NF/NP triple layered photoanode is significantly reduced. The observed higher electron lifetime determined from Bode plots shows that electron recombination is lower in the DSSCs made with the triple layered photoanode. Improved light harvesting by multiple scattering effects within the triple layered photoanode structure and the suppression of the electron recombination by Al2O3 sub-nanometer-sized coating around SnO2 appear to be the major factors for the enhancement in photo current density and efficiency.
We performed a meta-analysis of diagnostic data to evaluate the performance of Histoplasma antigen detection tests for diagnosing histoplasmosis. We included all studies involving human subjects that assessed the performance of any antigen detection test for histoplasmosis in urine or serum by carrying out an exhaustive and reproducible search of the literature between 1980 and 2014 from four databases. Quality of the articles was assessed, and meta-analysis was performed under the random effects model, calculating sensitivity, specificity, likelihood and odds ratios, and ROC curve using Meta-DiSc(es). Nine out of a total of 23 studies met strict quality criteria and were therefore included. The overall sensitivity for antigen detection in serum and urine was 81 % (95 % CI 78–83 %), while specificity was 99 % (95 % CI 98–99 %). Sensitivity for antigenuria and antigenemia was 79 % (95 % CI 76–82 %) and 82 % (95 % CI 79–85 %), respectively; specificity values were 99 % (95 % CI 98–100 %) in urine and 97 % (95 % CI 96–98 %) in serum. The positive and negative likelihood ratios were 49.5 (95 % CI 20.7–118.7) and 0.19 (95 % CI 0.14–0.26), respectively, while the diagnostic OR was 362 (95 % CI 121.2–1080.3) and area under the curve was 0.99. In conclusion, the performance of Histoplasma antigen detection assay of urine was not significantly different from that of blood, indicating that antigenuria and antigenemia have equal diagnostic value in histoplasmosis.
Spinel type CoFe2O4 thin films have been prepared, on stainless steel supports, by thermal decomposition of aqueous solutions of mixed cobalt and iron nitrates in 1:2 molar ratio at 400 °C. The electrochemical behaviour of the CoFe2O4/1 M KOH interface was investigated by cyclic voltammetry, chronoamperometry and impedance techniques. The studies allowed finding out the redox reactions occurring at the oxide surface. The results were compared with colloidal electrodes prepared by alkaline precipitation of Fe(II) or Fe(III) hydrous oxi-hydroxides on platinum electrodes. In addition, it has been concluded that the processes are diffusion-controlled and the diffusion of the hydroxide ion, through the oxide, acts as the rate-determining step. The diffusion coefficient of OH− through the oxide film was determined using cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy techniques.
We test the stability of pre-lithiated graphite anodes for Li-ion batteries in a dry room battery processing room. The reaction between LiC x and laboratory air was followed using operando NMR and x-ray diffraction, as these methods are sensitive to change in Li stoichiometry in graphite. There is minimal reactivity between LiC6 and N2, CO2 or O2; however, LiC6 reacts with moisture to form lithium (hydr)oxide. The reaction rate follows zero-order kinetics with respects to intercalated lithium suggesting that lithium transport through the graphite is fast. The reaction occurs by sequential formation of higher stages–LiC12, then LiC18, and then LiC24–as the hydrolysis proceeds to the formation of Li x OH y and graphite end products. Slowing down the formation rate of the Li x OH y passivation layer stabilizes of the higher stages.
This paper presents a fuzzy algorithm which makes decision so as to connect domestic apparatus on either the electrical grid or a photovoltaic panel (PVP). The decision is made in real time with respect to multi-energy save criteria and upon the PVP maximum available power and apparatus states. The algorithm is validated on a 1kW peak (kWp) PVP and domicile apparatus of different powers installed at the Energy and Thermal Research Centre (CRTEn) in the north of Tunisia. Criteria are verified on the system behaviour during days covering the different seasons of the year. The power audit, established using measures, confirms that the energy save during daylight reaches 90% of the PVP available energy.
With the development of new lithium-ion cell chemistries that provide comparatively safer designs with good power and energy densities, there is a large uptake of these cell types for such applications as portable electronics and battery-driven electric vehicles, and more recently their use as a power source for the starter lightning and ignition (SLI) of internal combustion engine vehicles. This review article looks at a range of factors specific to its application as a SLI battery in light of some of the technology challenges and market opportunities. The advantages of a lithium-ion SLI battery would primarily be in terms of its longer cycle-life and weight reduction when it is considered as a ‘drop-in’ replacement option for the existing lead-acid battery, which has dominated the SLI application market for the last 100 years. Aspects of safety, cost, design and testing specifications were considered in light of the emerging European battery legislations on the use of restrictive materials in vehicles. A brief overview of the life-cycle analysis and the increased demand for the recycling of lithium-ion batteries was done and its implications for both types of SLI batteries being able to be recycled effectively and be part of a circular economic product.
Density functional theory calculations are performed to investigate the role of lithium salts regarding the oxygen reduction reaction (ORR) occurred in non-aqueous electrolyte in Li-air batteries. This study is useful to elucidate the influence of ion-conducting lithium salts on ORR kinetics. The Li+-O bonding, binding energy, Gibb's free energy, heat of formation energy, and IR spectra with increase in dimethyl sulfoxide (DMSO) solvent molecules in the primary solvation shell reveal that lithium trifluoromethanesulfonate (LiCF3SO3) is the most stable in dimethyl sulfoxide (DMSO) as compared to lithium hexafluorophosphate (LiPF6) and lithium bis(trifluoromethanesulfonimide (LiN(CF3SO2)2). Infrared spectroscopic (IR) data confirm the formation of lithium peroxide (Li2O2), lithium oxide (Li2O), and lithium carbonate (Li2CO3) as discharge products on the micro-electrode surface in non-aqueous electrolyte containing lithium salts. The infrared (IR) analysis reveals that the lithium trifluoromethanesulfonate/dimethyl sulfoxide (LiCF3SO3/DMSO) electrolyte is primarily assumed to be the most favorable for ORR kinetics. In order to study the kinetics of oxygen reduction reaction at the oxygen cathode of non-aqueous Li-air battery with three Li salts in dimethyl sulfoxide (DMSO), we calculate thermodynamic properties of the reactions held during the formation of lithium peroxide (Li2O2) and lithium oxide (Li2O). The Gibb's energy and heat of formation of these reactions indicate that lithium trifluoromethanesulfonate/dimethyl sulfoxide (LiCF3SO3/DMSO) electrolyte plays a key role in oxygen reduction reaction mechanism compared to other two.
Lithium-ion batteries based on intercalation compounds have dominated the advanced portable energy storage market. The positive electrode materials in these batteries belong to a material group of lithium-conducting crystals that contain redox-active transition metal and lithium. Materials without lithium-conducting paths or lithium-free compounds could be rarely used as positive electrodes due to the incapability of reversible lithium intercalation or the necessity of using metallic lithium as negative electrodes. These constraints have significantly limited the choice of materials and retarded the development of new positive electrodes in lithium-ion batteries. Here, we demonstrate that lithium-free transition metal monoxides that do not contain lithium-conducting paths in their crystal structure can be converted into high-capacity positive electrodes in the electrochemical cell by initially decorating the monoxide surface with nanosized lithium fluoride. This unusual electrochemical behaviour is attributed to a surface conversion reaction mechanism in contrast with the classic lithium intercalation reaction. Our findings will offer a potential new path in the design of positive electrode materials in lithium-ion batteries.