batterydata/paper-abstracts huggingface dataset:
The edge plane in carbon structure has good electrocatalytic activity toward vanadium redox reaction. To apply it in vanadium redox flow battery (VRFB) practically, the graphite nanopowders (GNPs) containing amounts of edge planes are used as electrocatalyst and embedded in the electrospun carbon nanofibers (ECNFs) by different mass ratios to make composite electrodes. The morphology and electrochemical activity of the GNPs and the composite electrodes containing them are characterized. Compared with the pristine ECNFs, the composite electrodes show much higher electrochemical activity. With the increase of GNPs content in composite electrodes, the electrochemical reversibility of the vanadium redox couples also increases. It proves the addition of GNPs can surely improve the electrochemical activity of ECNFs. Among the composite electrodes, the ECNFs containing 30 nm GNP by mass ratio of 1:50 show the best electrochemical activity, largest active surface area and excellent stability. Due to the high performance of GNP/ECNFs composite electrode and its relatively low cost preparation process, the GNPs are expected to be used as electrocatalyst in VRFB on a large scale to improve the cell performance.
The effects of different lanthanum content (0, 0.00600, 0.0112, 0.0195 and 0.0540wt.%) on the electrochemical behavior of lead–lanthanum alloy in sulfuric acid solutions were investigated by linear potential sweep (LSV), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The morphology of the corrosion layer and corrosion section of Pb and Pb–La alloys were analyzed by scanning electron microscope (SEM) after corrosion testing. It was found that the addition of La inhibits the oxygen evolution reaction on the surface of Pb alloy electrodes, and La amounts of 0.00600 and 0.0540wt.% in Pb–La alloy electrodes can lead to a more effective inhibition. The results of the LSV, CV and EIS experiments show that the addition of La can inhibit the growth of the anodic Pb(II) oxides and PbO2 film. The resistance of the anodic film on the Pb–La electrodes is much lower than that on the Pb electrode. SEM for the corrosion layer indicates that the corrosion product on pure Pb and Pb–0.0195% La alloy is uniform and compact. The corrosion products on the alloys with La contents of 0.00600, 0.0112 and 0.0540 are loose and porous that the active materials can easily sit in the apertures to contact the grid surface intimately with the effective. The results demonstrate that Pb–La alloys show the potential for application as the positive grid material in maintenance-free lead-acid batteries.
The electrochemical properties of α-graphdiyne (α-GDY) for potassium ion storage were studied by first-principles calculations. Initial potassium ion (K+) insertion was dominated by K-carbon (C) ionic interactions, which was gradually replaced by K–K metallic interactions with further insertion. During the K+ insertion process, a portion of sp-hybridized C was transformed to sp2-hybridized C, while the working voltage gradually decreased to <0.5 V. Two layers of K+ were adsorbed on both sides of an α-GDY monolayer with low diffusion barriers of <0.25 eV, which resulted in a high theoretical capacity of 2870 mA h ∙g−1 with the formation of C14K18. Trilayer α-GDY exhibited a smaller theoretical capacity of 1700 mA h g−1, based on the formation of C42K32 resulting from both interlayer and surface K+ storage. Large hexagonal C-rings provided a small K+ diffusion barrier of 0.353 eV. As a result, K+ ions quickly “dropped” into the interlayer space across the α-GDY layer, while K+ intercalation between α-GDY layers was not favored due to a large diffusion barrier of 0.666 eV, resulting from the small interlayer distance of trilayer α-GDY. This study demonstrated promising electrochemical properties of α-GDY for potassium ion batteries, particularly for its large specific capacity and high rate capability.
India has a rich tradition of plant-based knowledge on healthcare. A large number of plants/plant extracts/decoctions or pastes are equally used by tribals and folklore traditions in India for treatment of cuts, wounds, and burns. The present review thus attempts to analyze the ethnobotanical knowledge base for treatment of cuts and wounds which includes a usage of plants, methods employed by tribals and folklore practices prevailing in India. Pharmacological reports available on Indian medicinal plants employing various wound healing models and its underlying molecular mechanism, wherever available, has also been briefly reviewed. This pharmacological validation on Indian medicinal plants is very limited and a large number of plants used in tribal and folklore with enormous potential have not been validated for their wound healing activity. This review therefore attempts to bridge the lacunae in the existing literature and offers immense scope for researchers engaged in validation of the traditional claims and development of safe and effective and globally accepted herbal drugs for cuts and wounds.
In this study, the cross-linking-type gel polymer electrolyte (GPE) was prepared using trimethylolpropane triacrylate and trimethylolpropane ethoxylate triacrylate and their electrochemical performances were evaluated. The ionic conductivity of the GPE at 20°C was around 5 × 10−3 ∼ 6 × 10−3 Scm−1. The GPE had good electrochemical stability up to 4.5V versus Li/Li+. The electrochemical performance of TMPETA-based cell was better than that of TMPTA-based cell. The discharge capacity of the TMPETA-based cell at the 2.0C rate was 98% of the discharge capacity at the 0.2C rate. The discharge capacity of the TMPTA- and TMPETA-based cell was stable with the charge–discharge cycling
The transfection of human mesenchymal stem cells (hMSCs) with the hyperpolarization-activated cyclic nucleotide-gated ion channel 2 (HCN2) gene has been demonstrated to provide biological pacing in dogs with complete heart block. The mechanism appears to be the generation of the ion current (If) by the HCN2-expressing hMSCs. However, it is not clear how the transfection process and/or the HCN2 gene affect the growth functions of the hMSCs. Therefore, we investigated survival, proliferation, cell cycle, and growth on a Kapton® scaffold of HCN2-expressing hMSCs.
Thermal runaway (TR) is a major safety concern in lithium-ion batteries. Model-based TR prediction is critically needed to optimize safety designs of cells. This paper presents a novel scheme for developing reliable battery TR model from kinetics analysis of cell components. First, differential scanning calorimetry (DSC) tests on the individual cell components and their mixtures are conducted to reveal the TR mechanism and characterize the exothermic reactions, of which the major six (such as the decomposition of solid electrolyte interface (SEI) film) are determined as the dominant heat sources. The kinetics parameters of each exothermic reactions are identified from the DSC tests results at variant heating rates using Kissinger’s method and nonlinear fitting method. A predictive battery TR model is established by superimposing the chemical kinetics equations of the six exothermic reactions. The model fits well with the adiabatic TR test results and the oven tests results of a 24 Ah lithium-ion battery, indicating that the model can well reflect the battery TR mechanism and be trusted to predict battery safety performance without assembling a real battery.
Electrochemical cells (ECs) are devices that convert chemical energy into electricity through spontaneous oxidation–reduction reactions that occur separately at two electrodes through the transport of protons in the electrolyte solution and the flow of electrons in the external circuit. A triboelectric nanogenerator (TENG) is an effective device that converts mechanical energy into electricity using organic/polymer materials by a contact induced electrification process followed by charge separation. In this paper, we demonstrate the first integration of an EC and a TENG for simultaneously harvesting chemical and mechanical energy, and its application for powering a sensor and even personal electronics. An EC was fabricated using a Cu/NaCl solution/Al structure, on which a thin polydimethylsiloxane (PDMS) film with a micropyramid surface structure was used as the protection layer of the EC for anti-corrosion, anti-contamination and anti-mechanical damage. A TENG was fabricated based on a contact-and-separation process between the PDMS protection layer and the Al electrode layer of the EC. The output performance of the TENG can be increased by embedding BaTiO3 nanoparticles into the PDMS film layer to enhance the dielectric property. Moreover, we also demonstrated that the produced hybrid energies can be stored in a Li-ion battery for lighting up 30 green LEDs.
One promising approach to reduce the cost of fuel cell systems is to develop hydroxide exchange membrane fuel cells (HEMFCs), which open up the possibility of platinum-group-metal-free catalysts and low-cost bipolar plates. However, scalable alkaline polyelectrolytes (hydroxide exchange membranes and hydroxide exchange ionomers), a key component of HEMFCs, with desired properties are currently unavailable, which presents a major barrier to the development of HEMFCs. Here we show hydroxide exchange membranes and hydroxide exchange ionomers based on poly(aryl piperidinium) (PAP) that simultaneously possess adequate ionic conductivity, chemical stability, mechanical robustness, gas separation and selective solubility. These properties originate from the combination of the piperidinium cation and the rigid ether-bond-free aryl backbone. A low-Pt membrane electrode assembly with a Ag-based cathode using PAP materials showed an excellent peak power density of 920 mW cm−2 and operated stably at a constant current density of 500 mA cm−2 for 300 h with H2/CO2-free air at 95 °C.
Consumers’ demand for portable audio/video/ICT products has driven the development of advanced power technologies in recent years. Fuel cells are a clean technology with low emissions levels, suitable for operation with renewable fuels and capable, in a next future, of replacing conventional power systems meeting the targets of the Kyoto Protocol for a society based on sustainable energy systems. Within such a perspective, the objective of the European project MOREPOWER (compact direct methanol fuel cells for portable applications) is the development of a low-cost, low temperature, portable direct methanol fuel cell (DMFC; nominal power 250W) with compact construction and modular design for the potential market area of weather stations, medical devices, signal units, gas sensors and security cameras. This investigation is focused on a conceptual study of the DMFC system carried out in the Matlab/Simulink® platform: the proposed scheme arrangements lead to a simple equipment architecture and a efficient process.
Nickel-rich metal oxides have been widely pursued as promising cathode materials for high energy-density lithium-ion batteries. Nickel-rich lithium transition metal oxides can deliver a high specific capacity during cycling, but can react with non-aqueous electrolytes. In this work, we have employed a full concentration gradient (FCG) design to provide a nickel-rich core to deliver high capacity and a manganese-rich outer layer to provide enhanced stability and cycle life. In situ high-energy X-ray diffraction was utilized to study the structural evolution of oxides during the solid-state synthesis of FCG lithium transition metal oxide with a nominal composition of LiNi0.6Mn0.2Co0.2O2. We found that both the pre-heating step and the sintering temperature were critical in controlling phase separation of the transition metal oxides and minimizing the content of Li2CO3 and NiO, both of which deteriorate the electrochemical performance of the final material. The insights revealed in this work can also be utilized for the design of other nickel-rich high energy-density cathode materials.
The edge-emitting semiconductor laser powered by Sifeu et al. oscillator is studied numerically. An electronic/analog model of the system is constructed in order to imitate the behavior of the material model. Period-doubling to chaos, is obtained when varying the amplitude of the reverse bias saturation current. The experimental results show agreement with those obtained numerically.
Exposure to cadmium, a heavy metal present in cigarettes, can be assessed in both urine and blood. Few studies have compared the properties of concurrent measurements of urine cadmium (uCd) and blood cadmium (bCd) in relation to the duration and timing of a known exposure. In this study, bCd and uCd were modeled with data from the National Health and Nutrition Examination Survey (1999–2010). Adjusted geometric mean bCd and uCd were estimated from regression results. Each 1% higher geometric mean uCd was associated with 0.50% (95% confidence interval: 0.47%–0.54%; R2=0.30) higher bCd. In male never-smokers, bCd was 69% (59%–81%) and uCd was 200% (166%–234%) higher at age ≥70 years versus 20–29 years. Ten pack-years (py) of smoking were associated with 13.7% (10.0%–17.4%) higher bCd and 16.8% (12.6%–21.1%) higher uCd in male smokers. The first year after smoking cessation was associated with 53% (48%–58%) lower bCd and 23% (14%–33%) lower uCd in representative males aged 55 years with 20 py smoking. Smoking in the previous 5 days was associated with 55% (40%–71%) higher bCd and 7% (−3%–18%) higher uCd. Results were similar for women. uCd mainly measures long-term exposure and bCd recent exposure, but with noticeable overlap. Epidemiological studies should base the choice of uCd or bCd on the timing of cadmium exposure relevant to the disease under study.
Silicon has been recognized as the most promising anode material for high-capacity lithium ion batteries. However, its large volume variation during the charge-discharge process results in electrode pulverization and fast capacity loss on cycling. The paper reports a facile synthesis of phenylalanine-functionalized graphene quantum dots (PF-GQD) through the pyrolysis of citric acid and phenylalanine. The PF-GQD was coated on the surface of silicon nanoparticles (SiNP) and then treated by thermal annealing in Ar/H2 to obtain PF-GQD@SiNP composite. The PF-GQD coating layer not only improves the electrical conductivity, but also effectively prevents the direct contact of silicon surface with the electrolyte molecules. The composite electrode exhibits an excellent electrochemical performance for lithium ion batteries. The specific capacity is 4066mAhg−1 at 50mAg−1, 3796mAhg−1 at 100mAg−1 and 1820mAhg−1 at 1000mAg−1. The capacity can remain 3068mAhg−1 after 100 cycles at 100mAg−1. As a control sample, alanine-functionalized graphene quantum dots (AF-GQD) was also prepared and used for the fabrication of AF-GQD@SiNP composite. The result shows that the electrochemical performance of PF-GQD@SiNP is much better than that of AF-GQD@SiNP. The improvement is attributed to the benzene ring at the edge of graphene sheets. Its introduction creates a wider and finer energy level of electron and well-defined steric structure compared to AF-GQD, which further accelerates the electron transfer and electrolyte transport and leads to an improved electrochemical performance. In addition, the study also provides an economic, eco-friendly and facile method for the fabrication of silicon-based anode materials for next generation high-performance lithium ion batteries.
Lithium (Li) metal is an ideal anode material for rechargeable batteries due to its extremely high theoretical specific capacity (3860 mA h g−1), low density (0.59 g cm−3) and the lowest negative electrochemical potential (−3.040 V vs. the standard hydrogen electrode). Unfortunately, uncontrollable dendritic Li growth and limited Coulombic efficiency during Li deposition/stripping inherent in these batteries have prevented their practical applications over the past 40 years. With the emergence of post-Li-ion batteries, safe and efficient operation of Li metal anodes has become an enabling technology which may determine the fate of several promising candidates for the next generation energy storage systems, including rechargeable Li–air batteries, Li–S batteries, and Li metal batteries which utilize intercalation compounds as cathodes. In this paper, various factors that affect the morphology and Coulombic efficiency of Li metal anodes have been analyzed. Technologies utilized to characterize the morphology of Li deposition and the results obtained by modelling of Li dendrite growth have also been reviewed. Finally, recent development and urgent need in this field are discussed.
With the development of flexible and wearable energy devices, it is highly desirable to exploit flexible and cost-effective electrode materials. In this work, we report a facile and in-situ method for preparing a three-dimensional (3D), flexible and binder-free anode material, composing of leaf-like MoS2 nanostructures uniformly anchored on carbon nanofibers derived from carbonized bacterial cellulose (denoted as MoS2-cBC). With merits of high conductivity, good flexibility and high structural stability, the MoS2-cBC composite was directly used as the anode material and current collector for lithium ion batteries without any binder nor conductive additive. Moreover, owing to the synergistic effect of the uniformly deposited MoS2 nanoleaves and the 3D highly conductive carbon nanofibers, the MoS2-cBC anode exhibits impressively superior electrochemical performance. A high reversible charge capacity of 935mAhg−1 is achieved at 0.1Ag−1, while a capacity of 581mAhg−1 is maintained after 1000 cycles at 1Ag−1 with negligible decay, demonstrating much enhanced long-term cycling stability of the composite. The superior electrochemical performance together with the stability and cost-effective merits make the MoS2-cBC composite promising for next-generation energy storage devices.
Solid-state 7Li NMR spectroscopy revealed different Ni/Co distributions in an inverse spinel structure of LiNi x Co1−x VO4 cathode materials prepared by either a high-temperature solid-state reaction method (abbreviated as the HT method) or a low-temperature solution co-precipitation method (abbreviated as the LT method). Solid-state 7Li NMR measurements confirmed that the lithium nuclear spin was dominated by a chemical shift anisotropy (CSA) interaction compounded with a small second-order quadrupolar interaction. Ni/Co distribution and inhomogeneity of chemical shift tensors (δ CSA and η CSA constants) associated with crystalline defects are accountable for the variation in spread of the MAS spinning side-band manifolds between nickel uptake and preparation methods. The NMR study also revealed that the HT method yielded broader Ni/Co distributions with greater lithium defects, while the LT method gave much more homogeneous Ni/Co distributions with smaller defects. The NMR results were consistent with XRD data that showed a gradual expansion in the unit-cell lattice with increasing Co content. All cells suffered a large irreversible loss in overall capacity in the first cycle and became stable in terms of cycle efficiency during later cycling. We have found that LiNi x Co1−x VO4 cathode materials prepared by the LT method with more homogeneous Ni/Co distribution and smaller crystalline defects offer a small advantage in capacity over the HT method.
Nitrogen-doped graphene hollow microspheres (NGHMs) were constructed, using polystyrene microspheres (PSMs) as the sacrificial template. Negatively charged graphene oxide nanosheets (GONs) were assembled onto sulfonated PSMs with the aid of poly(ethyleneimine) through electrostatic interaction. NGHMs were obtained by pyrolysis the mixture of melamine and GON-wrapped PSMs under a nitrogen atmosphere. During the pyrolysis, the removal of PSMs and reduction of GONs and incorporation of heteroatoms were realized simultaneously. The nitrogen atomic percentage in NGHMs reached 7.13%, and sulfur content was also detected. The prepared NGHMs exhibited high catalytic activity toward oxygen reduction reaction (ORR) in alkaline solution with a comparable limiting current density to JM 40 wt% Pt/C. The ORR on NGHMs electrode was dominated by the four-electron pathway in a wide potential range with long-term stability and high fuel selectivity. The enhanced electrocatalytic performance of NGHMs could be ascribed not only to the high nitrogen content, but also to the hollow sphere architecture. Moreover, the nitrogen precursor, melamine, increased the percentage of graphitic-N and prevented hollow spheres from aggregation, which also helped to improve the catalytic activity of NGHMs.
The fish species Notothenia angustata inhabits temperate waters (10 °C), yet retains physiological traits that show it once existed at sub-zero temperatures. We determined the free-ranging activity, heart rate and metabolism of N. angustata and compared it with Notothenia coriiceps, an ecologically and morphologically congeneric cousin that still inhabits sub-zero waters. Firstly, the association between heart rate (fH) and oxygen consumption (MO2) was first determined in the laboratory. The fish were then released into their respective environments and fH recorded by a miniature archival electronic tag, from which the metabolic rate of the free-ranging fish was extrapolated. Free-ranging activity of wild fish was monitored throughout the study using implanted acoustic tags and a static hydrophone array. Results showed that the difference in standard metabolic rate (SMR) between N. angustata and N. coriiceps fitted the Arrhenius model for inter-species thermal sensitivity in fish (Q 10 =1.76). However, the inter-species disparity in total metabolic rate (TMR) was far greater. This was attributable to N. angustata swimming at higher speeds and covering a 5-fold greater area over 24 h compared with N. coriiceps. As a result, activity (and associated feeding) comprised a far larger portion of TMR in N. angustata (27.9%) than for N. coriiceps (5.7%). We conclude that the increased time spent swimming by N. angustata was presumably to forage for food to acquire sufficient energy to fuel its elevated SMR. This resulted in a much greater inter-species difference in TMR than may be predicted by the disparity in environmental temperature.
Nano-composite polymer electrolytes are receiving attention as potential candidates to be used as electrolyte membranes in lithium polymer batteries and other devices. However, a survey of literature reveals that a systematic study of the effect of concentration and surface area of ceramic fillers on the conductivity enhancement of micro- and nano-composite polymer electrolytes is lacking. In this work, we have studied the thermal and electrical properties of the composite polymer electrolyte (PEO)9LiCF3SO3+Al2O3 incorporating alumina filler grains of four different sizes with different specific surface areas. The results show that the PEO crystallite melting temperature decreased by a few degrees in samples with fillers exhibiting a minimum for samples with high conductivity. The presence of the filler enhanced the ionic conductivity substantially above as well as below 60°C, and the nano-porous alumina grains with 5.8nm pore size and 150m2/g specific area and 15wt.% filler concentration exhibited the maximum enhancement. The observed conductivity enhancement has been attributed to Lewis acid–base type surface interactions of ionic species with O/OH groups on the filler surface, with an additional contribution below 60°C coming from the retention of an increased fraction of the amorphous phase due to the presence of the filler. The conductivity versus filler concentration curves exhibit two conductivity maxima which has been explained in terms of the surface interactions, blocking effect and grain consolidation. The conductivity enhancement appears to saturate beyond 100m2/g grain surface area.