batterydata/paper-abstracts huggingface dataset:
The La1-xSrxMnO3 (LSM) perovskites have been proposed as the promising oxygen reduction reaction catalysts (ORRCs) to substitute the noble metal. However, their ORR catalytic activities still need to be further improved. Here, the La0.7(Sr0.3-xPdx)MnO3 (LSPM) perovskites with the substitution of Sr with Pd are synthesized by a facile sol-gel method. The structure, morphology, valence state of Mn, oxygen adsorption behaviors of the different LSPM catalysts are investigated, and their ORR catalytic activities are studied by the rotating ring-disk electrode (RRDE) and aluminum air battery technologies. The results demonstrate that the appropriate substitution of Sr with Pd can effectively improve the ORR catalytic activity of La0.7Sr0.3MnO3 due to the regulation of the Mn valence and enhancement of the oxygen adsorption capacity. Among the LSPM perovskites, the LSPM-15 catalyst exhibits the best catalytic activity toward ORR. In addition, the current retention of LSPM-15 is as high as 98.9% after 10000s with the generation of a few HO2 − (0.96%∼1.56%) during the whole aging test. Moreover, the maximum power density of the aluminum air battery using LSPM-15 can reach 265.6mWcm−2, which indicates that LSPM-15 can be used as a promising ORRC for the aluminum air batteries.
This research work is targeting to demonstrate that micromirror arrays can also be fabricated successfully on flexible substrates—not only on glass substrates. The paper reports on the technological data of a successful process on a flexible substrate for curvilinear surfaces. Polyethylene naphthalate substrate was selected for its low cost, strong resistance against chemicals which are used in fabrication process and sufficient optical transmission for the visible and near infrared spectrum. Finally, electrostatic actuation of the fabricated micromirror structures is proven experimentally.
Understanding of the structural evolution of the cathode during the charge/discharge processes is crucial to describe the Li insertion/de-insertion mechanisms in a Li-ion battery. An in situ XRD cell has been specially fabricated to study a nanostructured electrode using a standard laboratory diffractometer. This cell was used to investigate phase transformations of a nanoporous Li2FeSiO4/C cathode in the initial charge/discharge cycle by in situ XRD as well as analyzing the full Li-ion battery by electrochemical impedance spectroscopy (EIS). The battery was operated in chronocoulometric mode for the in situ XRD and galvanostatic intermittent titration technique (GITT) mode for the EIS. Coexistence of two different polymorphs, P21/n and Pmn21 of Li2FeSiO4, was observed in the in situ XRD patterns. The amount of P21/n phase, which was the only phase present before cycling, decreased while the amount of Pmn21 phase increased during the first cycle. In the fully discharged state the Pmn21 phase appeared as the main phase. An inductive loop was observed in the impedance spectra which is believed to arise from the formation of a concentration cell (Li|P21/n||Pmn21|Li) from which current flows in opposition to the Li being intercalated/de-intercalated into and out of the Li2−x FeSiO4 electrode.
Patients with mild cognitive impairment experience difficulties in mathematics that affect their functioning in the activities of everyday life. What are the associated anatomical brain changes and the cognitive correlates underlying such deficits? In the present study, 33 patients with Mild Cognitive Impairments (MCI) and 29 cognitively normal controls underwent volumetric MRI, and completed the standardized battery of Numerical Activities of Daily Living (NADL) along with a comprehensive clinical neuropsychological assessment. Group differences were examined on the numerical tasks and volumetric brain measures. The gray (GM) and white matter (WM) volume correlates were also evaluated. The results showed that relative to controls, the MCI group had impairments in number comprehension, transcoding, written operations, and in daily activities involving time estimation and money usage. In the volumetric measures, group differences emerged for the transcoding subtask in the left insula and left superior temporal gyrus. Among MCI patients, number comprehension and formal numerical performance were correlated with volumetric variability in the right middle occipital areas and right frontal gyrus. Money-usage scores showed significant correlations with left mesial frontal cortex, right superior frontal and right superior temporal cortex. Regression models revealed that neuropsychological measures of long-term memory, language, visuo-spatial abilities, and abstract reasoning were predictive of the patients' decline in daily activities. The present findings suggest that early neuropathology in distributed cortical regions of the brain including frontal, temporal and occipital areas leads to a breakdown of cognitive abilities in MCI that impacts on numerical daily functioning. The findings have implications for diagnosis, clinical and domestic care of patients with MCI.
This paper investigates the cycle aging behavior of nickel-manganese-cobalt (NMC) lithium ion battery cells under high current rates and narrow window of State-of-Charge (SOC) variation for 48 V mild hybrid electric vehicle (HEV) applications. The charge sustaining aging profiles were synthesized from real-world duty cycles in some of the authors’ previous work [44,45] and used in the laboratory for life cycle aging testing spaced out by periodic cell capacity tests performed to assess cell aging conditions. Furthermore, at each 1C discharged aging characterization stage, the parameters of a physics-based electrochemical cell model were identified using the Bayesian Markov Chain Monte Carlo (MCMC) method. Among the parameters that can be identified with sufficient accuracy from the experimental data, the concentration of lithium-ions at the negative electrode after full charge is found to be strongly correlated with the system-level loss of capacity. These results provide new insights on the aging performance of NMC lithium ion cells in battery management system for 48 V hybrid vehicles.
Large format LiFePO4-based Li-ion batteries are rapidly becoming available from commercial cell manufacturers. In this paper two types of 10Ah single cells (one prismatic and another cylindrical) from two manufacturers were tested at room temperature and 60°C. Both cells suffered severe degradation at 60°C. The results were analyzed using incremental capacity analysis (ICA) along with other electrochemical techniques. Overall the two types of cells were similar in behavior, despite subtle differences in performance. This study shed some light on the degradation process associated with these two large format LiFePO4 cell designs with regard to thermal degradation at elevated temperatures. The analysis illustrates a unique capability of using ICA to differentiate cell performance and material utilization in different cell designs.
Carbon-coated cobalt sulfide (CoS) hollow nanoparticles on carbon nanotube (CNT) networks are synthesized by combining three simple approaches: direct growth of Co3O4 nanocrystals on the CNT backbones, chemical conversion of the Co3O4 nanocrystals to CoS hollow nanoparticles, and the spatial introduction of conformal surface modification by carbon. It is noteworthy that the CoS hollow nanoparticles with inner cavity of <50 nm and an average wall thickness of 6–8 nm are derived from a template-free method. Such a template-free-derived multifunctional nanostructure design achieves the amalgamation of the favorite traits of one-dimensional conducting networks, hollow nanoparticles, and surface modification, thus resulting in much enhanced charge transfer, ion transport, and upholding the integrity of the electrode and electrode/electrolyte interface. When applied the synthesized CoS-based material as anodes in sodium-ion batteries (SIBs), excellent performance is observed. For instance, a reversible specific capacity of 562 mAh g−1 at 100 mA g−1 and a capacity retention rate of 90% after 200 cycles at a higher current density of 500 mA g−1 are obtained. Moreover, a superior rate capability is observed with reversible specific capacities of 341 and 276 mAh g−1 at 2000 and at 5000 mA g−1, respectively.
A simple and effective strategy is proposed to activate carbon cloth for the fabrication of flexible and high-performance supercapacitors. Firstly, the carbon cloth surface is exfoliated as nanotextures through wet chemical treatment, then an annealing process is applied at H2/N2 atmosphere to reduce the surface oxygen functional groups which are mainly introduced from the first step. The activated carbon cloth electrode shows excellent wettablity, large surface area and delivers remarkable electrochemical performance. A maximum areal capacitance of 485.64 mF cm−2 at the current density of 2 mA cm−2 is achieved for the activated carbon cloth electrode, which is considerably larger than the resported results for carbon cloth. Furthermore, the flexible all-solid-state supercapacitor, which is fabricated based on the activated carbon cloth electrodes, shows high areal capacitance, superior cycling stability as well as stable electrochemical performance even under constant bending or twisting conditions. An areal capacitance of 161.28 mF cm−2 is achieved at the current density of 12.5 mA cm−2, and 104% of its initial capacitance is retained after 30,000 charging/discharging cycles. This study would also provide an effective way to boost devices' electrochemical performance by accommodating other active materials on the activated carbon cloth.
ABSTRACT Fe3C@carbonnanocapsules(*)/expanded graphite composite was successfully prepared by a new and facile method, including mix of starting materials and heat treatment of the precursor. It is featured by unique 3-D structure, where expanded graphite acts as scaffold to ensure a continuous entity, and Fe3C particles coated by carbon nanocapsules are embedded intimately. The Fe3C nanoparticles encased in carbon nanocapsules act as catalyst in the modification of SEI film during the cycles. The interesting 3-D architecture which aligns the conductivity paths in the planar direction with expanded graphite and in the axial direction with carbon nanocapsules minimizes the resistance and enhances the reversible capacity. The prepared composite exhibits a high reversible capacity and excellent rate performance as an anode material for lithium ion batteries. The composite maintains a reversible capacity of 1226.2mAh/g after 75 cycles at 66mA/g. When the current density increases to 200mA/g, the reversible capacity maintains 451.5mAh/g. The facile synthesis method and excellent electrochemical performances make the composite expected to be one of the most potential anode material for lithium ion batteries.
Polymer electrolyte membrane-based direct formic acid fuel cells (DFAFC) have been investigated for about a decade, and are now becoming an important area of portable power system research. DFAFCs have the advantages of high electromotive force (theoretical open circuit potential 1.48V), limited fuel crossover, and reasonable power densities at low temperatures. This paper provides a review of recent advances in DFAFCs, mainly focussing on the anodic catalysts for the electro-oxidation of formic acid. The fundamental DFAFC chemistry, formic acid crossover through Nafion® membranes, and DFAFC configuration development are also presented.
John Goodenough was born of U.S. parents in Jena, Germany, in 1922. He received a BA in mathematics from Yale University in 1943. After serving as a meteorologist for the USAAF in World War II, he obtained a Ph.D. in physics at the University of Chicago in 1952. From 1952 to 1976 he was at the Lincoln Laboratory of the Massachusetts Institute of Technology where he first helped to develop the ferrite-core coincident-current memory critical to the development of the digital computer and headed research groups in Magnetism and in Electronic Materials. It was during that period that he wrote his two books Magnetism and the Chemical Bond and Les oxydes des métaux de transition. From 1976 to 1986, he was Professor and Head of the Inorganic Chemistry Laboratory in Oxford, England, where his research concentrated on new materials for energy conversion. He developed the concept of framework structures for alkali-ion solid electrolytes and obtained the basic patents for layered and spinel oxides as cathodes for lithium secondary batteries. He also worked in photoelectrolysis for solar-energy conversion and catalytic electrodes for fuel cells. Since 1986, he has held a chair in the Materials Science and Engineering Center of the University of Texas at Austin where he has identified the LiFePO4 cathode for the Li+-ion battery, developed new electrolyte and electrode materials for the solid oxide fuel cell, and contributed significantly to our understanding of the unusual physical phenomena encountered at the crossover from localized to itinerant electronic behavior.
LiCoO2 had been successfully prepared from spherical basic cobalt carbonate via a simple uniform-phase precipitation method at normal pressure, using cobalt sulfate and urea as the reactants. The preparation of spherical basic cobalt carbonate was significantly dependant on synthetic condition, such as the reactant concentration, reaction temperature and impeller speed, etc. The optimized condition resulted in spherical basic cobalt carbonate with uniform particle size distribution, as observed by scanning electron microscopy. Calcination of the uniform basic cobalt carbonate with lithium carbonate at high temperature led to a well-ordered layer-structured LiCoO2 without shape change, as confirmed by X-ray diffraction. Due to the homogeneity of the basic cobalt carbonate, the final product, LiCoO2, was also significantly uniform, i.e., the average particle size was of about 10μm in diameter and the distribution was relatively narrow. As a result, the corresponding tap-density was also high approximately 2.60gcm−3, of which the value is higher than that of commercialized LiCoO2 of Hunan Ruixing, co. In the voltage range 2.8–4.2, 2.8–4.3, and 2.8–4.4V, the discharge capacities of LiCoO2 electrode were 153, 159, and 168mAhg−1, respectively, with better cyclability.
We report the application of free-standing, lightweight, and flexible graphene/Au composite paper (GACP), as a current collector for CF x cathode. At a high discharge current density of 4000 mA g−1 (5C), the capacity of the CF1.0 loaded on GACP current collector is 653 mAh g−1, while CF1.0 loaded on Al foil failed at 800 mA g−1 (1C). Using GACP, both excellent rate capability and specific capacity can be achieved simultaneously, owing to its undulant surface structure and flexible contact with the CF x composite active layer. Our results provide a new strategy to design both high power and energy densities CF x cathode.
Wind and solar energy are currently the most promising carbon-free sources of electrical energy. However, because of their unpredictable and intermittent nature, high penetration of solar and wind into the electrical grid will likely require energy storage in order to provide grid power balance. In this work we consider the storage requirements for 100% and nearly 100% wind and solar power, examining the effects of source diversity, geographical distribution of sources, overcapacity, and balancing power. As a case study we use load data from the Midcontinent Independent System Operator (MISO) energy market in the central region of the United States for the years 2007, 2008, 2009, and 2010. Solar and wind production is modeled using data from the National Renewable Energy Laboratory Solar and Wind Integration Data Sets. Our results show nearly an order of magnitude decrease in required energy storage capacity is achieved as the overcapacity is increased from 0 to 30% for optimized solar to wind ratios. Significant reductions also occur by allowing a balancing power of only a few percent. However, the corresponding storage discharge and balancing power capacities are a significant fraction of the solar and wind capacities with correspondingly low capacity factors.
Venous thromboembolism (VTE) is a common disorder that can lead to substantial morbidity and mortality through the clinical manifestations of deep vein thrombosis (DVT) and pulmonary embolism (PE). Although rapid diagnosis and treatment are critical in preventing PE, mortality and major morbidity due to conditions such as postthrombotic syndrome may complicate the differential diagnosis of VTE. The clinical symptoms associated with DVT are neither sensitive nor specific and can be indicative of a wide range of diagnoses. Because imaging studies can be expensive and are sometimes inconclusive, they should be used judiciously in patients with highly suspected VTE. This review offers a clinical perspective on the accurate, routine diagnosis of VTE, including an overview of common clinical signs and symptoms, as well as the advantages and drawbacks of available diagnostic strategies.
Cognitive impairment (CI) is a prevalent condition characterized by loss of brain volume and changes in cognition, motor function, and dual-tasking ability. To examine associations between brain volumes, dual-task performance, and gait and balance in those with CI to elucidate the mechanisms underlying loss of function. We performed a retrospective analysis of medical records of patients with CI and compared brain volumes, dual-task performance, and measures of gait and balance. Greater cognitive and combined dual-task effects (DTE) are associated with smaller brain volumes. In contrast, motor DTE is not associated with distinct pattern of brain volumes. As brain volumes decrease, dual-task performance becomes more motor prioritized. Cognitive DTE is more strongly associated with decreased performance on measures of gait and balance than motor DTE. Decreased gait and balance performance are also associated with increased motor task prioritization. Cognitive DTE appears to be more strongly associated with decreased automaticity and gait and balance ability than motor DTE and should be utilized as a clinical and research outcome measure in this population. The increased motor task prioritization associated with decreased brain volume and function indicates a potential for accommodative strategies to maximize function in those with CI. Counterintuitive correlations between motor brain volumes and motor DTE in our study suggest a complicated interaction between brain pathology and function.
A phase field description is formulated to describe the growth kinetics of an heterogeneously nucleated distribution of lithium electrodeposits. The underlying variational principle includes the bulk electrochemical contributions to the free energy of transformation of the system, the electrolyte-dendrite interfacial energy, and the substrate work of adhesion energetics. Results demonstrate that the rate of electrodeposition at the tip of an isolated dendrite is higher than the rate corresponding to the average overpotential, while the back contact is electrochemically shielded, thus favoring elongated, needle-like shapes. For large populations of electrochemically interacting deposits, two spatially distinct regions of behavior develop: one directly facing the counter-electrode where the local surficial electrodeposition dominates the local kinetics; and a second region, in the vicinity of the substrate–deposit interface, where the electrochemical shielding induced by the tip enables lateral electrochemical lithium exchange dendrite coalescence for small contact angle deposits, and dendrite dewetting and electrodissolution for large contact angle deposits. The underlying physical mechanisms through which some lithium nuclei detach from the depositing substrate, self-induce electrodissolution, while other continue to grow and coalesce are described for different contact angles.
The synthesis of nickel hydroxide by precipitation from a suitable solution containing dissolved Ni2+ ions is described. A large matrix of precipitation conditions is explored to generate a wide range of nickel hydroxide samples. While most precipitation reactions result in the formation of β-nickel hydroxide, the samples differ from one another in the degree of structural disorder as reflected by the differences in their powder X-ray diffraction (PXRD) patterns. A correlation of the long-range structure as deduced from diffraction studies with the short-range structure as deduced from infrared (IR) spectral studies is performed. The aim is to control the synthesis conditions to obtain materials with ‘tailor-made’ structural disorders.
This work introduces a facile strategy to improve the high-rate capability and cycling stability for carbon-free Li3V2(PO4)3 by coating with conducting polymer polyaniline. Core-shell Li3V2(PO4)3/polyaniline nanocomposite with typical sizes of 200nm has been synthesized via a microwave heating assisted sol-gel method followed by a self-assembly process. The highly conductive and uniform polyaniline layer coated on the surface of Li3V2(PO4)3 nanoparticles significantly enhances the electrochemical performance of the electrode, which exhibits better rate capability and excellent cycling stability compared with the pristine Li3V2(PO4)3. The resultant nanocomposite exhibits a high initial discharge capacity of 130.7mAhg−1 at 0.1C within a voltage range of 3.0-4.3V. When cycled at a rate of 10C the capacity can reach up to 101.5mAhg−1, and the capacity retention is 87.3% after 500 cycles. The likely contributing factor to the excellent electrochemical performance of core-shell Li3V2(PO4)3/polyaniline could be related to the uniform conducting polymer layer, which can improve the electrical conductivity of Li3V2(PO4)3.
Publisher Summary The chapter discusses frontotemporal dementia syndromes. Over the past decade there have been considerable advances in the understanding of neurodegenerative diseases producing focal cognitive deficits that typically involve the frontal and/or anterior temporal lobes (most commonly referred to collectively as either “frontotemporal dementia” (FTD) or “frontotemporal lobar degeneration” (FTLD). The chapter presents a classification, based on the clinical presentation and distinguishes three major clinical syndromes: frontal or behavioral variant FTD (bv -FTD), semantic dementia (SD), and progressive non-fluent aphasia (PNFA). The chapter reviews the evolution of the terms applied to this spectrum of disorders; to describe the key clinical, neuropsychological, and radiologic characteristics associated with the major syndromes; and to highlight recent developments in the genetics. In 1994, the Lund and Manchester groups introduced the term “FTD” to embrace both the behavioral and aphasic forms of focal demential and suggested tentative diagnostic criteria. Discovery of tau-gene mutations in some families with FTD lead to widespread use of the name. Apathy is the most common problem, manifesting as passivity, inertia, or inactivity together with social withdrawal. Disinhibition is a common early symptom and seems prevalent in those with right predominant frontal and temporal lobe dysfunction. Stereotypic and ritualistic behaviors such as preoccupation with counting or clockwatching, consistently choosing the same leisure activity, repeatedly eating the same food, and rigidly adherening to routine are all more common in the FTD subgroups than in Alzheimer's disease (AD). The chapter also discusses Progressive Non-Fluent Aphasia, familial frontotemporal dementia with Parkinsonism linked to chromosome 17, frontotemporal dementia with motor neuron disease, and others.