batterydata/paper-abstracts huggingface dataset:
The impact of electric overhead radiant heaters on the microclimate, air flows, transport and deposition of suspended particulate matter (SPM) was monitored between March 2004 and March 2005 in the historic churches of Saint Michael Archangel in Szalowa and Saint Catherine in Cracow (Poland). The measurements show that although irradiation at the floor level increases temperature and reduces relative humidity in the interior of the church, the effect out of the heated zone and for the surfaces sheltered from irradiation is very limited, i.e. their extent is comparable with natural fluctuations inherent to the local climate of the church. The radiant heaters proved to generate little convectional flow of the air. Therefore, the heating system was not found to increase the concentration of SPM indoors; in particular, no re-suspension of particles already present in the church was observed. This work has demonstrated that the overhead radiant heaters are capable of providing localised heat to the areas where people congregate without adversely affecting painted walls and the works of arts displayed in churches. Care, however, should be taken that sensitive works of art are not exposed to the direct infrared radiation.
Evaluating commercial Li-ion batteries presents some unique benefits. One of them is to use cells made from established fabrication process and form factor, such as those offered by the 18650 cylindrical configuration, to provide a common platform to investigate and understand performance deficiency and aging mechanism of target chemistry. Such an approach shall afford us to derive relevant information without influence from processing or form factor variability that may skew our understanding on cell-level issues. A series of 1.9Ah 18650 lithium ion cells developed by a commercial source using a composite positive electrode comprising {LiMn1/3Ni1/3Co1/3O2 +LiMn2O4} is being used as a platform for the investigation of certain key issues, particularly path-dependent aging and degradation in future plug-in hybrid electric vehicle (PHEV) applications, under the US Department of Energy's Applied Battery Research (ABR) program. Here we report in Part I the initial characterizations of the cell performance and Part II some aspects of cell degradation in 2C cycle aging. The initial characterizations, including cell-to-cell variability, are essential for life cycle performance characterization in the second part of the report when cell-aging phenomena are discussed. Due to the composite nature of the positive electrode, the features (or signature) derived from the incremental capacity (IC) of the cell appear rather complex. In this work, the method to index the observed IC peaks is discussed. Being able to index the IC signature in details is critical for analyzing and identifying degradation mechanism later in the cycle aging study.
Prospective positive-electrode (cathode) materials for a lithium secondary battery, viz., LiNi0.8Co0.2−x Al x O2 (x = 0.00, 0.01, 0.03, and 0.05), were synthesized using a sol–gel method and the structural and electrochemical properties are examined by means of X-ray diffraction, cyclic voltammetry, and charge–discharge tests. The LiNi0.8Co0.2−x Al x O2 maintains the α-NaFeO2-type layered structure regardless of the aluminium content in the range x ≤ 0.05. On the other hand, as the aluminium content is increased, the capacity retention of LiNi0.8Co0.2−x Al x O2 is improved while initial discharge capacity is slightly decreased. Results also show that the current peaks on the cyclic voltammograms are diminished and merged on aluminium addition. This suggests that the improved cycle stability of LiNi0.8Co0.2−x Al x O2 is due to suppression of the phase transition.
Flower-like SnS nanostructures are obtained by a simple solvothermal method for anode applications in Na-ion batteries. We show experimental evidence of progressive Sn agglomeration and crystalline Na2S enrichment at the end of de-sodiation process of the SnS electrode, both of which contribute to the capacity decay of the electrode upon repeated cycles. By replacing the commonly adopted acetylene black conductive additive with multi-wall carbon nanotubes (MWCNT), the cycle stability of the SnS electrode is largely improved, which correlates well with the observed suppression of both Sn agglomeration and Na2S enrichment at the end of de-sodiation cycle. A full cell is assembled with the SnS/MWCNT anode and the P2-Na2/3Ni1/3Mn1/2Ti1/6O2 cathode. An initial energy density of 262 Wh/kg (normalized to the total mass of cathode and anode) is demonstrated for the full cell, which retains 71% of the first discharge capacity after 40 cycles.
Capacity degradation monitoring of lithium batteries is necessary to ensure the reliability and safety of electric vehicles. However, capacity of cell is related to its complex internal physicochemical reactions and thermal effects and cannot be measured directly. A data-driven remaining capacity estimation approach for lithium-ion batteries based on charging health feature extraction is presented in this work. The proposed method utilizes rational analysis and principal component analysis to extract and optimize health features of charging stage which adapt to various working conditions of battery. The remaining capacity estimation is realized by relevance vector machine and validations of different working conditions are made with six battery data sets provided by NASA Prognostics Center of Excellence. The results show high efficiency and robustness of the proposed method.
The effect of FeS and PbS on capacity and self-discharge of an iron porous electrode used in a Fe–Ni battery was investigated. Addition of 1wt.% FeS or 1wt.% PbS promotes a significant increase in capacity and inhibits the self-discharge of the iron electrode. This effect is most significant in the presence of PbS.
To optimize lithium-ion batteries it is important to understand the formation of the solid electrolyte interphase (SEI) occurring at the graphitic anode during the first cycles. In this study we measured electrochemical impedance spectra at equidistant voltage intervals during first and second lithiation (charging process). The distribution of relaxation times (DRT) was calculated from the measured impedance spectra. Based on the DRT calculations an equivalent circuit was set up to evaluate the different impedance contributions. In addition to measurements at room temperature we also studied SEI behavior at elevated and lowered temperatures. Above 55°C we monitored an unwanted thermally induced electrolyte decomposition. Below −10°C an incomplete SEI formation was observed resulting in an increased impedance during the second lithiation. The activation energies of the different processes were calculated assuming Arrhenius behavior.
The aim of this workshop is to overview and discuss the practicalities of several new technologies for assessing physical activity and sedentary behaviour, including the most recent Actigraph GT3X+ model, the activPAL inclinometer, and the SenseWear armband. The workshop will provide information on when to use these devices (i.e., what sort of research study, who is being assessed), how to use these devices (battery charging, initialising, downloading) and data management issues.
New classes of proton-conducting membranes formed by incorporating Brönsted acid–base ionic liquids in a poly(vinyldenefluoride-co-hexafluoropropylene) PVdF polymer matrix, are here reported and discussed. We show that these membranes are characterized by high, thermally stable proton conductivity. However, this favourable property is in part contrasted by the release of the ionic liquid component, which may affect the long-term stability of the membranes. Various strategies are underway in our laboratory to solve this issue, and in this work we describe one of them, based on the dispersion of selected ceramic fillers in the polymer matrix. We show that this approach, while successful in enhancing the conductivity of the membranes, is not much effective in preventing the release of the ionic liquid component and thus, that other roads have to be explored to reach a satisfactory improvement of the integrity of the membrane.
We report a hybridized electromagnetic-triboelectric nanogenerator including an electromagnetic generator (EMG) and a triboelectric nanogenerator (TENG) for simultaneously scavenging wind energy. The TENG can deliver a largest output power of about 1.7mW under a loading resistance of 10MΩ, while the EMG can deliver a largest output power of about 2.5mW under a loading resistance of 1kΩ. A power management circuit has been designed to store the produced energy from the TENG into a capacitor, resulting in the enhanced energy-storage efficiency of up to 112% as compared with that of using a traditional rectifier. The charging rate of the capacitor by using the TENG has been optimized by changing the inductance and the switching on/off time. As compared with the individual TENG or EMG, the hybridized nanogenerator has a much better ability for sustainably powering a temperature sensor, exhibiting the potential applications of hybridized nanogenerators in self-powered sensor systems.
This work reports on the optimized preparation of a series of composites xLi2MnO3·(1− x)LiMn1/3Ni1/3Co1/3O2 (x =0.1–0.4) with an aim to find an advanced high-voltage cathode for lithium-ion batteries that can work at elevated temperatures. Developing a two-step molten-salt method leads to composites with a layered-type structure, showing a particle size distribution ranging from 350 to 450nm. The composites are featured by oxidation states stabilized as Mn4+, Ni2+, and Co3+, and by lattice occupation of Li+ in both transition-metal layers and lithium layer of LiMn1/3Ni1/3Co1/3O2. When acting as a cathode of lithium-ion batteries, the composite at x =0.3 shows an optimum electrochemical performance as characterized by a discharge capacity of 120mAhg−1 at a high current density of 500mAg−1 and a capacity retention of 64% after 20 cycles. Surprisingly, this electrochemical performance is significantly improved at elevated temperatures. Namely, discharge capacity is increased to 140.4mAhg−1 at a high current density of 500mAg−1, while average capacity decay rate becomes very small to 0.76%. These excellent performance is explained in terms of the dramatically improved lithium-ion diffusions in both electrode and surface films at elevated temperatures.
Introduction Faecal incontinence (FI) is a highly prevalent disorder that severely affects the health related quality of life (HRQOL) of the patients who suffer from it. Neuromodulation is a minimally invasive treatment that has demonstrated its efficacy in the treatment of FI symptoms over the past 10 years. The aim of this study is to check whether there is an improvement in the quality of life, using EuroQuol (EQ-5D), in patients with faecal incontinence treated with sacral root neuromodulation. Methodology An observational study with prospective recording of quality of life data, before and after, using the EuroQuol 5D on a series of patients diagnosed with moderate to severe FI with a complete or repaired sphincter who had a definitive MEDTRONIC Interstim® 3023 implant after a subchronic stimulation phase with a good response. Results The initial mean number of leaks was 3.1±1, and the final was 0.5±0.6. The mean number of escapes per week decreased to 2.6 escapes (95% CI: 2.1–3.1) after the definitive implant of the sacral root stimulator (P<.001). The mean baseline health status score was 55.9±13, and after neuromodulation it was 63.1±13. Thus, the visual analogue scale score increased by 7.1 points (95% CI: 0.37–14) after the definitive implant of the sacral root stimulator (P<.05). In the HRQOL variables studied with the EQ-5D questionnaire, we found an improvement with neuromodulation in the mobility and the presence of anxiety and/or depression variables. On the other hand we found an improvement with the neurostimulator implant, which was not significant, in personal care, performing daily activities and the presence of pain and/or discomfort. The current health was better in 11 patients (57.9%), the same in 7 (36.8%) and worse in 1 (5.3%). Conclusions Neuromodulation is a therapy that has demonstrated a significant improvement in HRQOL measured with the EQ-5D.
The magnesium insertion capability of Prussian blue (PB) analogue, potassium nickel hexacyanoferrate K0.86Ni[Fe(CN)6]0.954(H2O)0.766 (KNF-086), is demonstrated as a cathode material for rechargeable magnesium-ion batteries using a conventional organic electrolyte. K1.51Ni[Fe(CN)6]0.954(H2O)0.766 is synthesized first, and potassium ions are electrochemically extracted to prepare the KNF-086 cathode. The electrochemical test cell is composed of KNF-086 as the working electrode, an activated carbon as the counter and reference electrode, and 0.5 M Mg(ClO4)2 in acetonitrile as the electrolyte. The cell shows a reversible magnesium insertion/extraction reaction with a discharge capacity of 48.3 mAh g−1 at a 0.2 C rate, and an average discharge voltage at 2.99 V (vs. Mg/Mg2+) that is the highest among the cathode materials ever reported for magnesium-ion batteries. Elemental analysis and Fourier electron-density map analysis from powder X-ray diffraction data confirm that the magnesium-inserted phase is Mg0.27K0.86Ni[Fe(CN)6]0.954(H2O)0.766 (MKNF-086), and the magnesium ions in MKNF-086 are positioned at the center of the large interstitial cavities of cubic PB. Compared to KNF-086, MKNF-086 exhibits a decreased unit cell parameter (0.8%) and volume (2.4%). These results demonstrate that a PB analogue, potassium nickel hexacyanoferrate, could be utilized as a potential cathode material for conventional organic electrolyte-based magnesium-ion batteries.
The mechanical behaviors of lithium iron phosphate battery cells are investigated by conducting in-plane and out-of-plane compression tests of representative volume element (RVE) specimens of dry cells. The test results of cell RVE specimens under in-plane constrained compression indicate that the load carrying behavior of the cell RVE specimens is characterized by the buckling, the kink and shear band formation, and the final densification of the cell components. The SEM images of the active materials on electrodes and the test results of the cell RVE specimens under out-of-plane compression suggest that the porosity in the components and the macroscopic gaps between the components is up to 40%. The test results suggest that the lithium-ion battery cells can be modeled as anisotropic foams or cellular materials. The elastic buckling analyses for a beam with lateral constraints indicate that the higher order buckling modes and the critical buckling stresses in general agree with those observed in experiments. The elastic buckling analyses also justify the length selection of the cell RVE specimens. Finally, an idealized kinematic model is presented to explain the physical mechanisms of the kink and shear band formation in the cell RVE specimens under in-plane constrained compression.
This study uses sodium acetate as fuel to construct bioelectricity in coating-type three-dimensional microbial fuel cells anode. The coating-type three-dimensional anode was constructed using iron net as structural support, adhering a layer of carbon felt as primary coating and using carbon powder and 30% PTFE solution mixture as coating. The efficiency of electricity production and wastewater treatment were analyzed for the three-dimensional acetate-fed (C2H3NaO2) microbial fuel cells with the various ratio of the coating mixture. The results showed that the efficiency of electricity production was significantly improved when using the homemade coating-type microbial fuel cells anode compared with the one without coating on the iron net, which the apparent internal resistance was decreased by 59.4% and the maximum power density was increased by 1.5 times. It was found the electricity production was greatly influenced by the ratio of the carbon powder and PTFE in the coating. The electricity production was the highest with apparent internal resistance of 190 Ω, and maximum power density of 5189.4 mW m−3 when 750 mg of carbon powder and 10 ml of PTFE (i.e., ratio 75:1) was used in the coating. With the efficiency of electricity production, wide distribution and low cost of the raw materials, the homemade acetate-fed microbial fuel cells provides a valuable reference to the development of the composition microbial fuel cell anode production.
The types and properties of separators used for lead–acid batteries are reviewed. Attention is focused on the pocket-type polyethylene (PE) separator as this is widely used in present-day automotive batteries, i.e. in low-maintenance batteries with expanded lead–calcium grids. An improved PE separator has been developed by using a PE resin of high molecular weight. The resistance of the separator to attack by hot sulphuric acid is increased by a factor of 1.5. Batteries using the improved separator show a 40% increase in lifetime under the SAE 75°C life-cycle test.
The influence of Triton X-100 in enhancing the capacitance of polyaniline-based nickel electrodes is reported. Cyclic voltammetric experiments, galvanostatic charge–discharge studies and impedance analysis were carried out in order to investigate the applicability of the system as an electrochemical supercapacitor. A qualitative interpretation of the enhancement is provided. Fourier transform infrared (FTIR), X-ray diffraction and scanning electron microscopy techniques were employed for characterization of the electrode.
The recently discovered self-heating lithium ion battery has shown rapid self-heating from subzero temperatures and superior power thereafter, delivering a practical solution to poor battery performance at low temperatures. Here, we describe and validate an electrochemical-thermal coupled model developed specifically for computational design and improvement of the self-heating Li-ion battery (SHLB) where nickel foils are embedded in its structure. Predicting internal cell characteristics, such as current, temperature and Li-concentration distributions, the model is used to discover key design factors affecting the time and energy needed for self-heating and to explore advanced cell designs with the highest self-heating efficiency. It is found that ohmic heat generated in the nickel foil accounts for the majority of internal heat generation, resulting in a large internal temperature gradient from the nickel foil toward the outer cell surface. The large through-plane temperature gradient leads to highly non-uniform current distribution, and more importantly, is found to be the decisive factor affecting the heating time and energy consumption. A multi-sheet cell design is thus proposed and demonstrated to substantially minimize the temperature gradient, achieving 30% more rapid self-heating with 27% less energy consumption than those reported in the literature.
It is known that simulation of PV systems permits to study their performance helping engineers to design them. This paper deals with the dynamic simulation and modelling of stand-alone PV systems by using state variables and numerical integration methods. Two PV systems have been modelled and simulated: a PV array directly connected to a resistive load and a PV array with batteries also connected to a resistive load. A double exponential model, together with the procedure 1 for temperature and irradiance corrections of the IEC 60891 standard, has been used to model the PV array and considering the general battery model of Coppety with some modifications, the system with batteries was simulated. The obtained results from the simulations and experimental tests have been analysed and have shown that this methodology is a good option to simulate these systems.
The small fuel cell is being researched as an alternative power source to the Li-ion battery in mobile phone. In this paper, a direct hydrogen fuel cell system which powers a mobile phone without a supplementary battery is compactly integrated below 25ml volume at the backside of the phone. The system consists of a small (8ml) metal hydride hydrogen storage tank with 4L hydrogen storage or an energy density of ∼640Wh/L, a thin air-breathing planar polymer electrolyte membrane fuel cell (PEMFC) stack (13.44cm2 ×3mm for a volumetric power density of 335W/L), miniature pressure regulator, and a high efficiency DC–DC voltage converting circuitry. The hydrogen storage tank is packed with the AB5 type metal hydride alloy. The eight-cell air-breathing planar stack (8ml) is very thin (3mm) due to a thin flexible printed circuit board current collectors as well as a unique riveting assembly and is capable of a robust performance of 2.68W (200mW/cm2). A miniature pressure regulator is compact with fluidic and electrical connections within 4ml. A miniature DC–DC voltage converter operates at an overall efficiency of 90%. Consequently, the estimated energy density of a fully integrated fuel cell system is 205Wh/L (70.5Wh/kg).
This study estimated the level and determinants of airborne benzene concentrations in rural western Canada. A multi-site, multi-month unbalanced two-factorial design was used to collect air samples at 1206 fixed sites across a geographic area associated with primary oil and gas industry in Canadian provinces of Alberta, north-eastern British Columbia, and central and southern Saskatchewan from April 2001 to December 2002. Benzene concentrations integrated over 1 calendar month were determined using passive organic vapour monitors. Linear mixed effects models were applied to identify the determinants of airborne benzene concentrations, in particular the proximity to oil and gas facilities. The observed geometric mean of benzene concentrations was 158ngm−3, with large geometric standard deviation: 4.9. Benzene concentrations showed a seasonal variation with maxima in winter and minima in summer. Emissions from oil well (within 2km) and compressor influenced monthly airborne benzene concentrations. However, in our study, being located in the general area of a gas plant seems to be the most important in determining monthly airborne benzene concentrations. These findings support the need for investigation of the impact of oil and gas industry on quality of rural air.
Porous electrodes composed of multiphase active materials are widely used in Li-ion batteries, but their dynamics are poorly understood. Two-phase models are largely empirical, and no models exist for three or more phases. Using a modified porous electrode theory based on non-equilibrium thermodynamics, we show that experimental phase behavior can be accurately predicted from free energy models, without artificially placing phase boundaries or fitting the open circuit voltage. First, we simulate lithium intercalation in porous iron phosphate, a popular two-phase cathode, and show that the zero-current voltage gap, sloping voltage plateau and under-estimated exchange currents all result from size-dependent nucleation and mosaic instability. Next, we simulate porous graphite, the standard anode with three stable phases, and reproduce experimentally observed fronts of color-changing phase transformations. These results provide a framework for physics-based design and control for electrochemical systems with complex thermodynamics.