batterydata/paper-abstracts huggingface dataset:
During cycling, mechanical stresses can occur in the composite electrode, inside the active material, but also in the solid electrolyte interphase layer. A mechanical model is proposed based on a system made of a spherical graphite particle surrounded by the solid electrolyte interphase layer. During lithium intercalation or de-intercalation, stresses in the graphite are produced, governed by the diffusion induced stress phenomena and in the solid electrolyte interphase, driven by the graphite expansion. The stresses in both materials were simulated and a sensitivity analysis was performed to clarify the influence of principal parameters on both processes. Finally, assuming that the solid electrolyte interphase is the weakest material and therefore more prone to fracture than graphite, the experimental capacity fade during cycling was modeled based on its break and repair effect rather than on the fracture of the active material. The mechanical model of the solid electrolyte interphase was implemented in a single particle lithium ion battery model in order to reproduce capacity fade during battery lifetime. The model results were compared against cycle life aging experimental data, reproducing accurately the influence of the depth of discharge as well as the average state of charge on the capacity fade.
The galvanostatic intermittent titration technique (GITT) has been used as a standard method for evaluating chemical diffusion coefficients in electrode materials in the last three decades. It will now be demonstrated that these chemical diffusion coefficients evaluated with GITT are spurious as any reaction kinetics is neglected in the GITT theory. The neglect of the reaction kinetics leads to a spurious potential dependence of the GITT diffusion coefficients with minima at those potentials where the slow scan rate cyclic voltammogram or differential capacity plot exhibits peaks even in case where the true chemical diffusion coefficient is constant. This will be demonstrated by the evaluation of GITT diffusion coefficients from numerically generated GITT experiments calculated with a constant chemical diffusion coefficient on the example of a spinel-type LiMn2O4 electrode.
A research programme that aims to improve the state of the art in shoulder joint replacement surgery has been initiated at the Delft University of Technology. Development of improved endoprostheses for the upper extremities (DIPEX), as this effort is called, is a clinically driven multidisciplinary programme consisting of many contributory aspects. A part of this research programme focuses on the pre-operative planning and per-operative guidance issues. The ultimate goal of this part of the DIPEX project is to create a surgical support infrastructure that can be used to predict the optimal surgical protocol and can assist with the selection of the most suitable endoprosthesis for a particular patient. In the pre-operative planning phase, advanced biomechanical models of the endoprosthesis fixation and the musculo-skeletal system of the shoulder will be incorporated, which are adjusted to the individual's morphology. Subsequently, the support infrastructure must assist the surgeon during the operation in executing his surgical plan. In the per-operative phase, the chosen optimal position of the endoprosthesis can be realised using camera-assisted tools or mechanical guidance tools. In this article, the pathway towards the desired surgical support infrastructure is described. Furthermore, we discuss the pre-operative planning phase and the per-operative guidance phase, the initial work performed, and finally, possible approaches for improving prosthesis placement.
Photocatalytic reduction of CO2 to methanol offers a promising route to storage of solar energy in the form of chemical fuels. Here, Wu et al. use in operando microscopy to identify the active facets for CO2 reduction on Cu2O and exploit this to obtain high conversion efficiency and selectivity to methanol.
The present paper documents a comprehensive study on the ground impact of lithium-ion battery packs in electric vehicles. With the purpose of developing generic methodology, a hypothetic global finite element model is adopted. The force–displacement response of indentation process simulated by the global FE model is cross-validated with the earlier analytical solutions. The punching process after the armor plate perforation, the ensuing crack propagation of the armor plate as well as the local deformation modes of individual battery cells are clearly predicted by the global modeling. A parametric study is carried out, and a few underlying rules are revealed, providing important clues on the design of protective structure of battery packs against ground impact. In the next step, detailed FE models at the level of a single battery cell and shell casing are developed and simulations are performed using boundaries and loading conditions taken from the global solution. In the detailed modeling the failure of individual components is taken into account, which is an important indicator of electric short circuit of a battery cell and possible thermal runaway. The damage modes and the deformation tolerances of components in the battery cell under various loading conditions are observed and compared.
In an effort to improve the screening and diagnosis of individuals with Fetal Alcohol Spectrum Disorder (FASD), research has focused on the identification of a unique neurodevelopmental profile characteristic of this population. The objective of this review was to identify any existing neurodevelopmental profiles of FASD and review their classification function in order to identify gaps and limitations of the current literature.
Acid doped polybenzimidazoles (PBI) membrane is a type of promising proton exchange membrane for vanadium redox flow battery (VRFB) applications and increasing the basicity of PBI is an effective way to develop the acid doped level and proton conductivity. While according to Grotthuss mechanism, the proton conduct in PBI membranes can occur from protonated guest molecules to neighbor non-protonated neighbor molecules. Therefore, the flexibility of the polymer also can influence the proton conductivity of PBI membranes. In order to investigate in VRFB system which factor is more obvious, in this article, three PBI compounds with different basicity and flexibility were synthesized and then used to prepare dense proton exchange membranes for VRFB applications. The physicochemical properties and single cell performances of these membranes were valued. The results indicated that in VRFB system, the most flexible OPBI membranes show the highest proton conductivity. The VRFB used OPBI membrane as proton exchange membrane exhibited excellent cell performance, the energy efficiency (EE) of OPBI membrane reached 81.87% at current density of 100 mA cm−2, which was obviously higher than that of a commercial Nafion 115 membrane (EE = 77.69%). The self-discharge time of the OPBI membrane was recorded to be as long as 487 h, obviously longer than Nafion 115 (56 h).
Heat pipe cooling for battery thermal management systems (BTMSs) in electric vehicles (EVs) is growing due to its advantages of high cooling efficiency, compact structure and flexible geometry. Considering the transient conduction, phase change and uncertain thermal conditions in a heat pipe, it is challenging to obtain the dynamic thermal characteristics accurately in such complex heat and mass transfer process. In this paper, a “segmented” thermal resistance model of a heat pipe is proposed based on thermal circuit method. The equivalent conductivities of different segments, viz. the evaporator and condenser of pipe, are used to determine their own thermal parameters and conditions integrated into the thermal model of battery for a complete three-dimensional (3D) computational fluid dynamics (CFD) simulation. The proposed “segmented” model shows more precise than the “non-segmented” model by the comparison of simulated and experimental temperature distribution and variation of an ultra-thin micro heat pipe (UMHP) battery pack, and has less calculation error to obtain dynamic thermal behavior for exact thermal design, management and control of heat pipe BTMSs. Using the “segmented” model, the cooling effect of the UMHP pack with different natural/forced convection and arrangements is predicted, and the results correspond well to the tests.
Spherical Li[Li0.2Ni0.2Mn0.6]O2 has been synthesized by a carbonate co-precipitation method. The Li[Li0.2Ni0.2Mn0.6]O2 with a phase-pure and well-ordered layered structure was synthesized by heat-treatment of a spherical (Ni0.25Mn0.75)3O4 precursor with LiOH·H2O. The average particle size of the Li[Li0.2Ni0.2Mn0.6]O2 powders was approximately 20μm and the size distribution was quite narrow due to the homogeneity of the (Ni0.25Mn0.75)CO3. The Li[Li0.2Ni0.2Mn0.6]O2 electrode calcined at 900°C delivered an initial discharge capacity of approximately 270mAhg−1 in the voltage range of 2.0–4.6V. The differential scanning calorimetry (DSC) results for the Li[Li0.2Ni0.2Mn0.6]O2 prepared at 900°C showed a major exothermic reaction at 270°C.
Out recent achievements in the development of three-dimensional (3D) thin film microbatteries on silicon and on microchannel plates (MCP) are presented. In such 3D microbatteries, the battery sandwich-like structure, including electrodes, electrolyte and current collectors, is deposited conformally on all available surfaces, thereby utilizing the dead volume of the substrate. Thin-film molybdenum oxysulfide and iron sulfide cathodes were deposited galvanostatically. XRD, XPS and TOF–SIMS characterizations indicated that the submicron thick MoO y S z films were amorphous, with the stoichiometry of the films varying with depth. Electrodeposited FeS x films have an amorphous, network-like porous structure with nanosize particles. A special flow cell for conformal coating of the perforated substrates was designed. A Li/hybrid polymer electrolyte (HPE)/MoO y S z -on-Si 3D half cell ran at i d = i ch =10μAcm−2 and room temperature for 100charge/discharge cycles with 0.1%/cycle capacity loss and 100% Faradaic efficiency. A 3D half cell on MCP exhibited 20 times higher capacity than that of a planar half cell with the same footprint.
Carbon encapsulation of electrode materials is way to improve lifetime of lithium ion batteries by minimizing direct contact with electrolyte. However achieving uniform carbon encapsulation on electrochemically active metal oxides, specifically on layered compounds, is an extremely challenging task because of the contrastive-ambient requirement for the formation of carbon coating and the oxide. We demonstrate a novel in-situ method for uniform encapsulation of carbon on LiNi1/3Mn1/3Co1/3O2 (LNMCO) using ethylene glycol (EG), which is intercalated in metal hydroxide interlayers pillaring the structure. Heat treating EG-pillared Ni1/3Co1/3Mn1/3(OH)2 with lithium hydroxide under air ambient results in an uniform carbon coating during the growth and crystallization of LiNi1/3Mn1/3Co1/3O2 particles. The trapping of carbon precursors in between the collapsed hydroxide layers minimizes the reaction of carbon precursor with oxygen even when heat-treated in air. This in-situ carbon encapsulation mechanism is revealed using detailed analyses carried out by Raman spectroscopy, TEM, EDS mapping and thermal analysis coupled with mass spectroscopy. Superior cyclic stability of C-LiNi1/3Mn1/3Co1/3O2 with a capacity retention of 82% (75%) after 150 (300) cycles of charging/discharging is demonstrated with an optimum carbon thickness in contrast to 42% capacity retention in uncoated LNMCO samples after 100 cycles.
The common strategy to address the low electronic conductivity of LiFePO4 is to downsize LiFePO4 and to coat the nanocrystal with conductive carbon film. The major issues with existing carbon coating techniques are thickness and quality control. This paper reports a facile carbon coating method which can provide ultrathin, uniform and fully encapsulating carbon coating on LiFePO4. This coating method capitalizes on the redox chemistry of surface Fe3+ on solvothermally synthesized LiFePO4 nanocrystal, to deposit uniform thin films of polydopamine films. The polymer film is easily carbonized into ultrathin carbon film. The carbon coated LiFePO4 exhibits very high rate performance (143 mAh g−1 at current density of 1700 mA g−1) with excellent capacity retention.
Size reduction in nanocrystals leads to a variety of exciting phenomena due to enhanced surface-to-volume ratio and reduced transport length for the mobile charges. We consider some of these anomalous phenomena restricting our discussions to the effects of nano-size on energetics and transport behaviour, with a few examples to illustrate materials challenges for efficient energy conversion and storage. We show that nano-size affects the thermodynamical aspects due to excess surface contributions giving rise to enhanced cell voltage in lithium batteries. An anomalous electrical conduction occurs at nano-size, its relevance is briefly highlighted in the context of energy conversion using fuel cells and excitonic solar cells. The benefit of narrowly spaced interfaces also results in rapid energy storage due to the reduction of the effective diffusion path. Thus, in the context of storage behaviour, nanocrystalline electrodes exhibit high capacity as well as Coulombic efficiency and in some cases high rate performance. An interfacial lithium storage mechanism which is a consequence of nanocrystallinity has been discussed to explain the extra storage when metal is brought in contact with Li2O/LiF at nanosize. Superior storage performance by supercapacitors and efficient waste heat conversion by thermoelectric devices using nanostructured materials are also briefly highlighted. This review thus emphasises fundamental understanding and novel concepts at nano-size for the development of excellent materials which achieve efficient energy conversion and storage, both of which are vital in facing the challenges posed by global warming and the predicted future limited energy resources.
This communication aims to propose new insights of Nb2O5-based coatings on the 316L SS surface with great prospects to be used in the dentistry field as brackets. The Nb2O5 thin film was incorporated into the 316L SS by using PVD method. For this purpose, the studied system was characterized structurally and morphologically by using AFM, FTIR-IRRAS, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Biological assays were performed using human gingival fibroblast cell-line HGF-1. In agreement with FTIR and Raman results, the XPS technique indicates that Nb is present in an oxidation state assigned to Nb2O5. Furthermore, the coatings produced by PVD technique are less toxic and induces less inflammation in gingival cells (cell-line HGF-1), suggesting the strategy of use Nb2O5 thin film to cover the 316L SS promoted since its protection of the physiological environment to its biocompatibility improvement.
Objectives To compute left ventricular (LV) twist from 3-dimensional (3D) echocardiography. Background LV twist is a sensitive index of cardiac performance. Conventional 2-dimensional based methods of computing LV twist are cumbersome and subject to errors. Methods We studied 10 adult open-chest pigs. The pre-load to the heart was altered by temporary controlled occlusion of the inferior vena cava, and myocardial ischemia was produced by ligating the left anterior descending coronary artery. Full-volume 3D loops were reconstructed by stitching of pyramidal volumes acquired from 7 consecutive heart beats with electrocardiography gating on a Philips IE33 system (Philips Medical Systems, Andover, Massachusetts) at baseline and other steady states. Polar coordinate data of the 3D images were entered into an envelope detection program implemented in MatLab (The MathWorks, Inc., Natick, Massachusetts), and speckle motion was tracked using nonrigid image registration with spline-based transformation parameterization. The 3D displacement field was obtained, and rotation at apical and basal planes was computed. LV twist was derived as the net difference of apical and basal rotation. Sonomicrometry data of cardiac motion were also acquired from crystals anchored to epicardium in apical and basal planes at all states. Results The 3D dense tracking slightly overestimated the LV twist, but detected changes in LV twist at different states and showed good correlation (r = 0.89) when compared with sonomicrometry-derived twist at all steady states. In open chest pigs, peak cardiac twist was increased with reduction of pre-load from inferior vena cava occlusion from 6.25° ± 1.65° to 9.45° ± 1.95°. With myocardial ischemia from left anterior descending coronary artery ligation, twist was decreased to 4.90° ± 0.85° (r = 0.8759). Conclusions Despite lower spatiotemporal resolution of 3D echocardiography, LV twist and torsion can be computed accurately.
Karl Przibram is one of the pioneers of early solid state physics in the field of the interdependence of coloration effects and luminescence in solids (crystals, minerals) induced by radiation. In 1921 Przibram discovered the effect of radio-photoluminescence, the light-stimulated phosphorescence in activated crystals induced by gamma rays. In 1926 Przibram was the first to use the term, Farbzentrum (color center, F-center), and in 1923 he advanced the view of atomic centers as carriers of coloration. Being a pupil of Ludwig Boltzmann and Franz S. Exner, he dedicated his early work to condensation and conductivity phenomena in gases and Brownian motion. Under the influence of Stefan Meyer, he began his lifelong interest in mineralogy, setting up his own research group at the Vienna Radium Institute, which pioneered investigations on thermoluminescence and gave a first description of glow curves. Being of Jewish descent, Przibram had to leave Austria after the Nazis took power; he found shelter in Belgium and returned to Austria in 1946 as professor for experimental physics at the University of Vienna. This paper is a first attempt to give an overview of the cultural and scientific background of Przibram’s life and science in context of the cultural and political developments from 1900 to 1950 in Austria.
The design and fabrication of the materials to improve their performance are crucial for energy storage of lithium-ion batteries and supercapacitors. Herein, the CuCo2S4 nanocrystallites grown on N-doped amorphous carbon coated CNTs are synthesized via a facile solvothermal method (CNTs@NC@CuCo2S4). The N-doped amorphous carbon layer with functional groups can effectively strengthen the adhesion between CNTs matrix and CuCo2S4 nanocrystallites. The combination of nanocrystallites and the CNTs not only shortens the diffusion path of the electrolyte, but also enhances the electrical conductivity of the electrode. As a result, the CNTs@NC@CuCo2S4 displays excellent electrochemical performance both in lithium-ion batteries and supercapacitors. The reversible capacity can be retained at 783 mAh g−1 after 100 cycles at the current density of 100 mA g−1. And the discharge capacity of 507 mAh g−1 is still maintained after 60 cycles even at high rate of 5000 mA g−1. As the electrode for supercapacitors, the CNTs@NC@CuCo2S4 delivers good capacitive performance with high capability (1604 F g-1 at 1 A g−1), good rate capability, and enhanced cycling stability, with 93.6% capacitance retention after 2000 cycles at the current density of 2 A g−1.
Stable power supply is essential for various long-term sea floor geophysical observations. Due to a simple structure and a large energy capacity, sea-water batteries have been developed and used for such observations. However, the characteristics of sea-water batteries have not been well known in the case of installations at depths more than 5000m in deep-sea basin. In 2000, a sea floor borehole broadband seismic observatory was installed in the northwestern Pacific basin where the water depth is 5577m. For electric power supply, a Sea-Water Battery (SWB) system with monitoring and control was developed and used. The SWB system consists of four sea-water battery cells, a DC/DC converter, the Power Control System, the Data Logger, and an accumulator. The conditions of the SWB system were recorded more than 1 year, and the monitoring data was recovered. The SWB system generated enough power for the observation system consuming power of 6W in average and continued to supply power for at least 5 years. From the monitoring data, the SWB can supply up to the long-term average of at least 13W. The energy density is estimated to be 318Whkg−1. The sea-water battery is useful for application of long-term power consumption even in the deep-sea basin.
A total of 81 toddlers (24–27months of age) participated in a biobehavioral investigation of inhibitory control. Maternal report measures of inhibitory control were related to laboratory tasks assessing inhibitory abilities under conditions of conflict, delay, and compliance challenge as well as toddler verbal ability. In addition, unique variance in inhibitory control was explained by task-related changes in brain electrical activity at lateral frontal scalp sites as well as concurrent inhibitory task performance. Implications regarding neural correlates of executive function during early development and a central organizing role of inhibitory processing during toddlerhood are discussed.
A simple two-step solid-state-reaction process is adopted to synthesize carbon-coated Mg-doped Li(Mn,Fe)PO4 (LMMFP) nano-particles. As positive electrode materials for lithium-ion batteries, the carbon-coated LMMFP samples show excellent electrochemical properties in a temperature range from −20 to 55 °C. For example, LiMn0.48Fe0.5Mg0.02PO4 can deliver a capacity of 146.2 mAh g−1 at 3C rate and retain 95.3% after 450 cycles at 25 °C. It can also deliver 160.7 mAh g−1 at 1C and retain 97.7% after 100 cycles at 55 °C. Even at −20 °C, it gives a capacity of 109.5 mAh g−1 with an average discharge voltage of 3.37 V at 0.2C. In Na/LMMFP cells, the LMMFP electrodes can be electrochemically converted into Mg-doped Na(Mn,Fe)PO4 (NMMFP) electrodes for sodium-ion batteries (SIBs). Ex-situ XRD proves that the derived NMMFP have an olivine-type structure and can reversibly extract and insert sodium ions. For example, NaMn0.48Fe0.5Mg0.02PO4 can deliver a reversible specific capacity of 126.9 mAh g−1 after 30 cycles at 0.1C with an average discharge voltage of 3.1 V. This study opens up a new direction on exploring olivine-type SIB cathodes.
Australia’s Pacific Coast near Brisbane is a popular year round vacation destination that is developing rapidly. Vacationers are drawn by the area’s warm climate, clean air, miles of beaches, and superb surfing conditions. While the rapid growth has made new facilities necessary, including many handrails, balustrades, and swimming pool fences, this area is a corrosive environment for construction materials.