batterydata/paper-abstracts huggingface dataset:
Electrochemical reactions of lithium with cubic α-Li2ZnGe and with hexagonal Li2ZnSi have been studied. Charging a Li/α-Li2ZnGe battery results in lithium extraction to yield a Li1.2ZnGe composition, through a first step at ca. 0.9 V that involves a phase transition from cubic to hexagonal, and a second step at ca. 1.1 V where Ge and Zn segregation is observed. By discharge of the Li/α-Li2ZnGe battery, the composition Li3ZnGe is reached at 0.2 V while the cubic structure is maintained. Lithium insertion into Li2ZnSi preserves the hexagonal structure, but lithium extraction modifies the X-ray diffraction pattern.
We report herein on several phenomenological electrode–solution interactions which determine the performance of lithium and lithium ion batteries. This review is based on extensive studies of the behavior of Li, lithiated carbons and lithiated transition metal oxide electrodes in a wide variety of non-aqueous electrolyte solutions. These studies included spectroscopic measurements (FTIR, XPS, EDAX), morphological and structural analysis (XRD, SEM, AFM) in conjunction with impedance spectroscopy, EQCM and standard electrochemical techniques. It appears that the performance of both Li, Li–C anodes and Li x MO y cathodes depends on their surface chemistry in solutions. We address complicated surface film formation on these electrodes, which either contribute to electrode stabilization or to capacity fading due to an increase in the electrodes' impedance. Several common classical phenomena occurring in these systems are reviewed and discussed.
In this work we have determined the room temperature electrochemical reactions of SnO2 thin films and mesoporous carbons filled with SnO2 anodes with Na, and compare the results with those obtained during the reaction with Li. We show that SnO2 can reversibly deliver up to 6.2 Li/SnO2 whereas the reaction with Na is significantly limited. The initial discharge capacity is equivalent to less than 4 Na/SnO2, which is expected to correspond to the formation of 2 Na2O and Sn. This limited discharge capacity suggests the negative role of the formed Na2O matrix upon the reversible reaction of Sn clusters. Moreover, the reversible cycling of less than 1 Na/SnO2, despite the utilization of 6–7 nm SnO2 particles, is indicative of sluggish reaction kinetics. The origin of this significant capacity reduction is probably due to the formation of a diffusion limiting interface. Furthermore, there is a larger apparent hysteresis compared to Li. These results point to the need to design composite structures of SnO2 nanoparticles with suitable morphological and conductivity components.
Olivine, LiFePO4 is a promising cathode material for lithium-ion batteries due to its low cost, environmental acceptability and high stability. Its low electric conductivity prevented it for a long time from being used in large-scale applications. Decreasing its particle size along with carbon coating significantly improves electronic conductivity and lithium diffusion. With respect to the controlled formation of very small particles with large specific surface, gas-phase synthesis opens an economic and flexible route towards high-quality battery materials. Amorphous FePO4 was synthesized as precursor material for LiFePO4 by flame spray pyrolysis of a solution of iron acetylacetonate and tributyl phosphate in toluene. The pristine FePO4 with a specific surface from 126–218 m2 g−1 was post-processed to LiFePO4/C composite material via a solid-state reaction using Li2CO3 and glucose. The final olivine LiFePO4/C particles still showed a large specific surface of 24 m2 g−1 and were characterized using X-ray diffraction (XRD), electron microscopy, X-ray photoelectron spectrocopy (XPS) and elemental analysis. Electrochemical investigations of the final LiFePO4/C composites show reversible capacities of more than 145 mAh g−1 (about 115 mAh g−1 with respect to the total coating mass). The material supports high drain rates at 16 C while delivering 40 mAh g−1 and causes excellent cycle stability.
Reduced graphene nanosheet/urchin-like manganese dioxide (GNS/MnO2) composite for a supercapacitor electrode has been fabricated by a mild hydrothermal route. Following investigation by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), we propose an in situ formation of MnO2 nanoparticles onto graphene nanosheets. The unique structure greatly increases specific surface area of the composite and the utilization of MnO2. The electrochemical performance of the electrode is analyzed by cyclic voltammetry, electrochemical impedance spectrometry and chronopotentiometry. Results show that the GNS/MnO2 composite exhibits a maximum specific capacitance of 263Fg−1 and an excellent cycle life with capacity retention of about 99% after 500 cycles. The method provides a facile and straightforward approach to deposit MnO2 nanoparticles onto graphene sheets; it could be readily extended to the preparation of other classes of hybrids based on GNS sheets for technological application.
Li-rich, Mn-rich (LMR) layered composite has attracted extensive interests because of its highest energy density among all cathode candidates for lithium ion batteries (LIB). However, capacity degradation and voltage fading remain the major challenges for LMR cathodes prior to their practical applications. Here, we demonstrate that anion receptor, tris(pentafluorophenyl)borane ((C6F5)3B, TPFPB), substantially enhances the stability of electrode/electrolyte interface and thus improves the cycling stability of LMR cathode Li[Li0.2Ni0.2Mn0.6]O2. In the presence of 0.2 M TPFPB, Li[Li0.2Ni0.2Mn0.6]O2 shows an improved capacity retention of 76.8% after 500 cycles. It is proposed that TPFPB effectively confines the highly active oxygen species released from structural lattice through its strong coordination ability and high oxygen solubility. The electrolyte decomposition caused by the oxygen species attack is therefore largely mitigated, forming reduced amount of byproducts on the cathode surface. Additionally, other salts such as insulating LiF derived from electrolyte decomposition are also soluble in the presence of TPFPB. The collective effects of TPFPB mitigate the accumulation of parasitic reaction products and stabilize the interfacial resistances between cathode and electrolyte during extended cycling, thus significantly improving the cycling performance of Li[Li0.2Ni0.2Mn0.6]O2.
Objective To describe the pattern of cognitive impairment among children and adolescents with multiple sclerosis (MS) according to the International Pediatric MS Study Group criteria. Methods We analyzed cognitive performance using the computerized neuropsychological battery (GAB, NeuroTrax) in 20 patients with juvenile MS, mean+SD age at disease onset 13.4+2.8 years (range 9–16 years), 10 females, 10 males within 1 year from diagnosis. The GAB assesses performance across an array of cognitive domains including: memory, executive function, visual spatial perception, verbal function, attention, information processing speed, and motor skills with a combined global cognitive scoring (GCS). Results The mean GCS in the juvenile MS group was 93.7 (below the mean for age and education norms), and similarly decreased performance was observed in all domains as follows: memory (92.1) and specifically non-verbal memory (90.7), executive function (94.5), visual spatial perception (90.7), verbal function (88.4), attention (97.4), information processing speed (93.6), and motor skills (100.1). Conclusion Cognitive performance was decreased in children and adolescences with MS already during the first year from disease onset. The most impaired domain was verbal function suggesting targeted intervention should be early employed.
The purpose of the paper is to review the utility of the global positioning system (GPS) in the study of health-related physical activity. The paper draws from existing literature to outline the current work performed using GPS to examine transport-related physical activity, with a focus on the relative utility of the approach when combined with geographic information system (GIS) and other data sources including accelerometers. The paper argues that GPS, especially when used in combination with GIS and accelerometery, offers great promise in objectively measuring and studying the relationship of numerous environmental attributes to human behaviour in terms of physical activity and transport-related activity. Limitations to the use of GPS for the purpose of monitoring health-related physical activity are presented, and recommendations for future avenues of research are discussed.
Highly efficient and non-precious catalysts are imperative for oxygen reduction reaction (ORR) to replace Pt/C. Anchoring efficient active species to carbon supports is a promising and scalable strategy. Here we synthesize Cu nanoparticles and noncrystalline CuN x C y species co-decorated ketjenblack (KB) carbon catalyst (denoted as Cu-N-KB-acid) by a facile and scalable method using copper sulfate, melamine, and KB as raw materials. An initial one-pot hydrothermal treatment is designed before pyrolysis process to achieve the good distribution of Cu and melamine on KB via a possible chelation effect. Owing to the synergistic effect of Cu and CuN x C y on KB, this composite catalyst displays excellent ORR catalytic activity in alkaline solution, which is comparable to the commercial 20% Pt/C. When used as a catalyst in a home-made Al–air battery, it shows a stable discharge voltage of 1.47 V at a discharge density of 50 mA cm−2, a little higher than that of Pt/C (1.45 V).
Paper and textiles have been used ubiquitously in our everyday lives, such as books and newspapers for propagating information, clothing and packaging. In this perspective, we will summarize our recent efforts in exploring these old materials for emerging energy and environmental applications. The motivations and challenges of using paper and textiles for device applications will be discussed. Various types of energy and environmental devices have been demonstrated including supercapacitors, Li-ion batteries, microbial fuel cells and water filters. Due to their unique morphologies, paper and textile-based devices not only can be fabricated with simple processing, but also show outstanding device performance. Being renewable and earth-abundant materials, paper and textiles could play significant roles in addressing future energy and environmental challenges.
In an attempt to reduce the Li+ concentration polarization and electrolyte depletion from the electrode porous space, sulfonated polyether ether ketone with pendant lithiated fluorinated sulfonic groups (SPEEK-FSA-Li) is prepared and attempted as ionic conductivity binder. Sulfonated aromatic poly(ether ether ketone) exhibits strong adhesion and chemical stability, and lithiated fluorinated sulfonic side chains help to enhance the ionic conductivity and Li+ ion diffusion due to the charge delocalization over the sulfonic chain. The performances are evaluated by cyclic voltammetry, electrochemical impedance spectroscopy, charge–discharge cycle testing, 180° peel testing, and compared with the cathode prepared with polyvinylidene fluoride binder. The electrode prepared with SPEEK-FSA-Li binder forms the relatively smaller resistances of both the SEI and the charge transfer of lithium ion transport. This is beneficial to lithium ion intercalation and de-intercalation of the cathode during discharging–charging, therefore the cell prepared with SPEEK-FSA-Li shows lower charge plateau potential and higher discharge plateau potential. Compared with PVDF, the electrode with ionic binder shows smaller decrease in capacity with the increasing of cycle rate. Meanwhile, adhesion strength of electrode prepared with SPEEK-FSA-Li is more than five times greater than that with PVDF.
A facile and selective hydrothermal synthesis is performed to control the crystalline phases of cobalt hydroxides into α-Co(OH)2 and β-Co(OH)2: α-Co(OH)2, consisting of both octahedral and tetrahedral Co sites, is produced without ionic liquids, whereas β-Co(OH)2, containing octahedral Co sites, is synthesized in the presence of ionic liquids. The ionic liquids play significant role as co-solvent and template to tune the morphology of Co(OH)2. α-Co(OH)2 reveals flake-like structure, whereas β-Co(OH)2 exhibits nanorod-like network structure. The interlayer spacing of α-Co(OH)2 is 8.24 Å, which is larger than 4.63 Å of β-Co(OH)2 due to the expansion of interlayer by the precursor Cl─ anions. The presence of Cl─ anions hinders the insertion of hydroxide ion into α-Co(OH)2 interlayers, which shows the specific capacitance of 613 F g─1 less than 1066 F g─1 of β-Co(OH)2 at 2 A g─1. When the current density increases up to 20 A g─1, the capacitance retention of β-Co(OH)2 is 80%, greater than 70% of α-Co(OH)2. Configuring β-Co(OH)2 and reduced graphene oxide as positive and negative electrodes, asymmetric supercapacitor delivers the maximum energy and power densities of 20.05 W h kg─1 and 13.40 kW kg─1 with the capacitance retention of 93% over 10,000 cycles.
As the number of fuel-cell vehicles on the roads increase, the vehicle designs are gaining more importance. Clearly, one major topic in this field is the optimization of powertrain designs. In this design process, the aim of the car manufacturers is to meet the expectations of the potential customer best, while creating a sustainable product. However, due to several trade-offs in the design, it would be non-realistic to expect a single solution that fulfills all design objectives. Therefore, a systematical approach, which includes a trade-off analysis and evaluation methods for this multiobjective design problem, is required. In this paper, a suitable methodology is presented and applied in a case study, where an optimum powertrain design for a typical European long-range passenger car is sought. Simulation-aided powertrain models and scalable component models are used to increase the accuracy of the design process. Furthermore, various visual and quantitative evaluation techniques are applied in order to support the decision making process.
Various compositions of tin-rich, non-stoichiometric, solid solutions of Sn4+ δ P3 are synthesized by a mechanochemical method. The materials are tested as anodes for lithium secondary batteries to enhance reversible capacity and cycleability. Investigative analyses show that the region for the solid-solution formation of Sn4+ δ P3 is 0≤ δ ≤1. The reaction mechanism of the tin-rich solid solutions is similar to that of stoichiometric Sn4P3, except for the absence of a topotactic lithium insertion reaction during the first cycle. As the tin content is increased, tin-rich phosphide exhibits better cycleability and retains a higher reversible capacity, namely, about 20% more than that of stoichiometric Sn4P3.
A technology tree (TechTree) is a branching diagram that expresses relationships among product components, technologies, or functions of a technology in a specific technology area. A TechTree identifies strategic core technologies and is a useful tool to support decision making in a given market environment for organizations with specified capabilities. However, existing TechTrees generally overemphasize qualitative and expert-dependent knowledge rather than incorporating quantitative and objective information. In addition, the traditional process of developing a TechTree requires vast amounts of information, which costs considerably in terms of time, and cannot provide integrated information from a variety of technological perspectives simultaneously. To remedy these problems, this research presents a text mining approach based on Subject–Action–Object (SAO) structures; this approach develops a TechTree by extracting and analyzing SAO structures from patent documents. The extracted SAO structures are categorized by similarities, and are identified by the type of technological implications. To demonstrate the feasibility of the proposed approach, we developed a TechTree regarding Proton Exchange Fuel Cell technology.
The physicochemical properties of molten alkali bis(trifluoromethylsulfonyl)amide, MTFSI (M=Li, K, Cs), mixture (x LiTFSI =0.20, x KTFSI =0.10, x CsTFSI =0.70) were studied to develop a new rechargeable lithium battery operating at intermediate temperature (100–180°C). The viscosity and ionic conductivity of this melt at 150°C are 87.2cP and 14.2mScm−1, respectively. The cyclic voltammetry revealed that the electrochemical window at 150°C is as wide as 5.0V, and that the electrochemical deposition/dissolution of lithium metal occurs at the cathode limit. A Li/MTFSI (M=Li, K, Cs)/LiFePO4 cell showed an excellent cycle performance at a constant current rate of C/10 at 150°C; 95% of the initial discharge capacity was maintained after 50 cycles. Except for the initial few cycles, the coulombic efficiencies were approximately 100% for all the cycles, indicating the stabilities of the molten MTFSI mixture and all the electrode materials.
A series of mesoporous LiFePO4/C microspheres have been successfully synthesized via a hydrothermal process using citric acid as chelating agent and reductant. The growth evolution process of the precursor is systematically investigated based on the time-dependent experiments. Pure mesoporous LiFePO4 microspheres are obtained with a diameter of ∼2μm, which are composed of numerous compact nanoparticles (∼200nm). These microspheric LiFePO4 shows high tap density (1.35gcm−3) and large Brunauer–Emmett–Teller (BET) surface area (20.992m2 g−1), which favor the electrochemical properties. The initial discharge capacity of LiFePO4/C microspheres is 163.8mAhg−1 at 0.1C rate, corresponding to 96.4% of the theoretical capacity of LiFePO4 (170mAhg−1). The material also shows excellent high rate capability (120.3mAhg−1, 10C), and cycling stability (a capacity retention of 98.1% at 0.5C rate after 200 cycles).
Tissue oxygenation index (TOI) using the near infrared spectroscopy (NIRS) has been demonstrated as a useful indicator to predict return of spontaneous circulation (ROSC) among out-of-hospital cardiac arrest (OHCA) patients in hospital setting. However, it has not been widely examined based on pre-hospital setting.
This paper focuses on state of charge (SOC) dependent mechanical failure analysis of 18650 lithium-ion battery to detect signs of thermal runaway. Quasi-static loading conditions are used with four test protocols (Rod, Circular punch, three-point bend and flat plate) to analyse the propagation of mechanical failures and failure induced temperature changes. Finite element analysis (FEA) is used to model single battery cell with the concentric layered formation which represents a complete cell. The numerical simulation model is designed with solid element formation where stell casing and all layers followed the same formation, and fine mesh is used for all layers. Experimental work is also performed to analyse deformation of 18650 lithium-ion cell. The numerical simulation model is validated with experimental results. Deformation of cell mimics thermal runaway and various thermal runaway detection strategies are employed in this work including, force-displacement, voltage-temperature, stress-strain, SOC dependency and separator failure. Results show that cell can undergo severe conditions even with no fracture or rupture, these conditions may slow to develop but they can lead to catastrophic failures. The numerical simulation technique is proved to be useful in predicting initial battery failures, and results are in good correlation with the experimental results.
Particle swarm optimization is a stochastic optimization, evolutionary and simulating algorithm derived from human behaviour and animal behaviour as well. Special property of particle swarm optimization is that it can be operated in continuous real number space directly, does not use gradient of an objective function similar to other algorithms. Particle swarm optimization has few parameters to adjust, is easy to implement and has special characteristic of memory. Paper presents extensive review of literature available on concept, development and modification of Particle swarm optimization. This paper is structured as first concept and development of PSO is discussed then modification with inertia weight and constriction factor is discussed. Issues related to parameter tuning, dynamic environments, stagnation, and hybridization are also discussed, including a brief review of selected works on particle swarm optimization, followed by application of PSO in Solar Photovoltaics.
Geopolitical and economic factors have motivated the scientific community to utilize renewable energy resources. In addition to the modifications in major steps and processes of biofuel production, manipulation of microbial genome engineering tools is essential in order to find sustainable solution of continuous depletion of fossil-fuels. Recently, the CRISPR (clustered regularly interspaced short palindromic repeat)/Cas9 (CRISPR-associated nuclease 9), a prokaryotic molecular immunity system, has emerged as a novel technology for targeted genomic engineering. This genetic machinery seems to be a groundbreaking discovery to engineer the microbial genomes for desired traits such as enhancing the biofuel tolerance, inhibitor tolerance and thermotolerance as well as modifying the cellulases and hemicelluloses enzymes. In this review, a summary of different generations of biofuels, integrated processes of bioconversion of raw materials into biofuels and role of microbes in biofuel production has been presented. However, the ultimate focus of the review is on major discoveries of CRISPR/Cas9-mediated genome editing in microorganisms and exploitation of these discoveries for enhanced biofuel production.
Vanadium dioxide (VO2) thin films with pure Monoclinic phase could be transformed from B-phase by inserting TiO2 buffer layers on transparent amorphous glass substrates at the low temperature of 400 °C. This crystalline transformation might be ascribed to oxygen-deficient environment induced by the TiO2 buffer layer and the template effect of TiO2 layer for M-VO2 phase. The simplicity in phase regulation of the present method and the superior optical and electrical properties of the films may allow its wide applications in thermo-opto-electro sensing devices.
Multiple courses are being offered at one location during IGTI Turbomachinery Training Week. Courses include: Gas Turbines & Compressors; Root Cause Failure Analysis; Rotor and Blade Dynamics; Field, Factory Testing and Dynamics.
A cathode half cell physics-based model for a St. Jude Medical fabricated silver vanadium oxide (SVO) cathode coin cell battery was constructed. The model is based on a single particle Fick's second law approach with the open-circuit potential modeled with a Redlich–Kister equation. By assuming that lithium ions intercalate only through the ends of the cuboid SVO particles, the model is able to predict accurately the discharge profile of experimental cathode half cell coin cells.