batterydata/paper-abstracts huggingface dataset:
Because of their advantages, polymer solar cells (PSCs) are one of the most promising candidates for the next generation power source of various wearable and optoelectronic applications. However, the damage caused by washing, which is essential for wearable applications, deteriorates the characteristics of the device and conventional encapsulation barriers. This study developed an encapsulation barrier which prevented moisture permeability even during the washing process, by introducing a SiO2–polymer composite capping layer. The chemical stability imparted by a reaction between SiO2 and Al2O3 can prevent the phase transitions that are the cause of degradation. The proposed encapsulation barrier preserves its physical and chemical properties, such as thickness, roughness, and permeability, after washing. Also, we proposed a real textile-based PSC, which is a profitable wearable device, since it uses the textile itself as a platform. This means that the PSCs are very flexible and can be designed to match energy consumption by controlling the power area. Finally, it was determined that textile-based optoelectronic modules including PSCs, organic light emitting diodes, and the proposed encapsulation barrier exhibited little change in characteristics even after 20 washings with 10 minutes cycles. In addition, the encapsulated device operated stably with a low curvature radius (3 mm) and boasted high reliability. It exhibited no deterioration in properties over 30 days even after being subjected to both bending stress and washing. This work suggests an important direction for the practical realization of wearable optoelectronic devices on real textiles.
Oxygen electrocatalysis is of great importance for many energy storage and conversion technologies, including fuel cells, metal–air batteries and water electrolysis. Replacing noble metal-based electrocatalysts with highly efficient and inexpensive non-noble metal-based oxygen electrocatalysts is critical for the practical applications of these technologies. Here we report a general approach for the synthesis of hollow frameworks of nitrogen-doped carbon nanotubes derived from metal–organic frameworks, which exhibit higher electrocatalytic activity and stability for oxygen reduction and evolution than commercial Pt/C electrocatalysts. The remarkable electrochemical properties are mainly attributed to the synergistic effect from chemical compositions and the robust hollow structure composed of interconnected crystalline nitrogen-doped carbon nanotubes. The presented strategy for controlled design and synthesis of metal–organic framework-derived functional nanomaterials offers prospects in developing highly active electrocatalysts in electrochemical energy devices.
Hierarchical tubular structures constructed from rutile TiO2 nanorods are fabricated, using MnO2 nanorods as sacrificial templates. The resultant rutile TiO2 hierarchical nanotubes show unique structural features (hierarchical, hollow) and a large surface area (180m2 g−1), which substantially improve their electrochemical performance. This type of hierarchical structures with high porosity produced by neighboring building blocks, are desirable for the development of sodium ion batteries, because the large amounts of pores can enhance the contact areas between electrode and electrolyte, and faciliate the ion diffusion during the charge/discharge process. As an anode material for sodium ion batteries, these hierarchical nanotubes deliver a high reversible capacity of 221mAhg−1 at 0.3C (100mAg−1), superior rate capability with a stable capacity of 71mAhg−1 at 15C, and good long-term cycling stability with a capacity of 79mAhg−1 after 1000 cycles at 3C. The superior sodium storage performances make this rutile TiO2 hierarchical nanotube a promising anode metarial for sodium ion batteries.
This paper presents a study of a new system called Système Réfléchissant à Lames Orientables (Orientable Blades Reflective System) (SRLO). This solar hybrid concentrated system is able to produce both thermal and electrical energy. Following the technological advances of recent years, it appears as the outcome of several prototypes improved over time. SRLO can now be considered as a flexible distributed generation system which can be integrated into a microgrid. First, we present the evolution of the system over time and its operation. Then, we focus on the astronomical parameters representing the position of the sun and the specific trigonometric calculations of reflections and shadows. They make it possible to calculate the energy optimum, to operate the control-command and to define the operating profiles. These parameters are also used to obtain the optimal position of the receiver considering the shadow of the reflecting structure. Finally, this study allows the estimation of the concentration rate of the system at any time as well as the solar energy received by the PV modules.
Introduction Although accurate diagnosis of deficit of mild intensity is critical, various methods are used to assess, dichotomize and integrate performance, with no validated gold standard. This study described and validated a framework for the analysis of cognitive performance. Methods This study was performed by using the Groupe de Réflexion sur L'Evaluation des Fonctions EXécutives (GREFEX) database (724 controls and 461 patients) examined by 7 tests assessing executive functions. The first phase determined the criteria for the cutoff scores, the second phase, the effect of test number on diagnostic accuracy and the third phase, the best methods for combining test scores into an overall summary score. Four validation criteria were used: determination of impaired performance as compared to expected one, false-positive rate ≤5%, detection of both single and multiple impairments with optimal sensitivity. Results The procedure based on 5th percentile cutoffs determined from standardized residuals was the most appropriate procedure. Although area under the curve (AUC) increased with the number of scores (p = .0001), the false-positive rate also increased (p = .0001), resulting in suboptimal sensitivity for detecting selective impairment. Two overall summary scores, the average of the seven process scores and the Item Response Theory (IRT) score, had significantly (p = .0001) higher AUCs, even for patients with a selective impairment, and provided higher resulting prevalence of dysexecutive disorders (p = .0001). Conclusions The present study provides and validates a generative framework for the interpretation of cognitive data. Two overall summary score met all 4 validation criteria. A practical consequence is the need to profoundly modify the analysis and interpretation of cognitive assessments for both routine use and clinical research.
The energy density of an electrochemical capacitor can be significantly improved by utilizing a lithiated negative electrode and a high surface area positive electrode. During lithiation of the negative carbon electrode, the electrolyte reacts with the electrode surface and undergoes decomposition to form a solid electrolyte interphase (SEI) layer that passivates the surface of the carbon electrode from further reactions between Li and the electrolyte. The reduction reactions that the solvent undergoes also form insoluble and gaseous by-products. In this work, those gaseous by-products generated by reductive decomposition of a carbonate-based electrolyte, 1.2M LiPF6 in EC/PC/DEC (3:1:4), were analyzed at different stages during the lithiation process of an amorphous carbon electrode. The stages in the generation of gaseous by-products were determined to come as a result of two, 1-electron reduction steps of the cyclic carbonate components of the electrolyte. Electrochemical impedance spectroscopy was also used to investigate the two distinct electrochemical processes and the development of the two phases of the SEI structure. This is the first time that the state of an electrochemical cell during the formation of the SEI layer has been systematically correlated with theoretical reaction mechanisms through the use of in situ electrochemical-MS and impedance spectroscopy analyses.
Though aluminum foils are widely applied as cathode current collectors for lithium ion batteries, they still face many challenges, such as the limited contact area, weak adhesion with electrode materials and localized corrosion by electrolytes during long-term cycling, which will lead to the degradation of electrochemical performances. Here, graphene-modified aluminum foils and carbon black/graphene modified aluminum foils are prepared as the current collectors for lithium iron phosphate lithium ion batteries by a facile solution coating method. We find that the batteries fabricated with carbon black/graphene-modified aluminum foils exhibit largely improved electrochemical performances in rate capability, internal resistance and long-term cycling capacity retention, compared with the bare aluminum and graphene-modified aluminum foils. This work reveals the coatings of graphene nanosheets not only can increase the contact area and enhance the adhesion between electrode materials and current collectors, which is beneficial for their electrical contact and charge transport, but also can suppress the aluminum foil corrosion during long-term cycling. Meanwhile, the excessive coverage of graphene nanosheets will lower the battery performances due to the interlayer contact increment of graphene nanosheets. In addition, carbon black combines graphene to form a co-conductive network effectively compensating the low interlayer electrical conductivity of graphene nanosheets.
Meeting inter-seasonal fluctuations in electricity production or demand in a system dominated by renewable energy requires the cheap, reliable and accessible storage of energy on a scale that is currently challenging to achieve. Commercially mature compressed-air energy storage could be applied to porous rocks in sedimentary basins worldwide, where legacy data from hydrocarbon exploration are available, and if geographically close to renewable energy sources. Here we present a modelling approach to predict the potential for compressed-air energy storage in porous rocks. By combining this with an extensive geological database, we provide a regional assessment of this potential for the United Kingdom. We find the potential storage capacity is equivalent to approximately 160% of the United Kingdom’s electricity consumption for January and February 2017 (77–96 TWh), with a roundtrip energy efficiency of 54–59%. This UK storage potential is achievable at costs in the range US$0.42–4.71 kWh−1.
In this work we introduce a new direction for the performance improvement of rechargeable lithium/sulfur batteries by employing an electrolyte that promotes Li anode passivation in lithium polysulfide solutions. To examine our concept, we assemble and characterize Li/Li2S9 liquid cells by using a porous carbon electrode as the current collector and a 0.25m Li2S9 solution as the catholyte. Results show that Li/Li2S9 liquid cells are superior to conventional Li/S cells in specific capacity and capacity retention. We also find that use of LiNO3 as a co-salt in the Li2S9 catholyte significantly increases the cell's Coulombic efficiency. More importantly, the cells with LiNO3 have a ∼2.5V voltage plateau before the end of charging and demonstrate a steep voltage rise at the end of charging. The former is indicative of the formation of elemental sulfur from soluble lithium polysulfides on the carbon electrode, and the latter provides a distinct signal for full charging. Electrochemical analyses on Li plating and stripping in Li2S9 catholyte solutions indicate that LiNO3 participates in the formation of a highly protective passivation film on the Li metal surface, which effectively prevents the Li anode from chemical reaction with polysulfide anions in the electrolyte and meanwhile prevents polysulfide anions from electrochemical reduction on the Li surface.
Résumé La batterie psychométrique BAC 40 est essentiellement destinée au diagnostic des démences, mais aussi à l’examen neuropsychologique en pratique courante pour les spécialistes de neurologie, gériatres et psychiatres. Nous présentons les résultats globaux de l’étude de validation de la BAC 40. L’étude se base sur une comparaison entre les scores à la BAC 40 et ceux obtenus par les mêmes personnes à la partie cognitive de l’Alzheimer Disease Assessment Scale, chez une centaine de sujets normaux en bonne santé, et le même nombre de personnes consultant pour une plainte mnésique. La grille comporte un examen exhaustif des fonctions supérieures, de durée courte, 15 à 20minutes, permettant un diagnostic de démence. Les scores normaux sont fournis, selon les tranches d’âge (de 37,9 chez les plus jeunes, à 31,9 chez les plus âgés). Nous avons pu montrer une excellente corrélation entre les deux échelles, aussi bien chez les témoins que chez les sujets consultant pour une plainte mnésique. On ne peut donner de score pathologique à la BAC 40 si l’on ne tient pas compte de l’âge du sujet. Toutefois, un score situé en dessous de la limite inférieure dans cette tranche, diminué de l’écart-type, est fortement en faveur d’un syndrome démentiel. Enfin, un score situé entre 30 et 40, dont le déficit est lié aux items de mémoire (dix points), est en faveur d’une atteinte mnésique isolée, qui doit être surveillée.
The hereditary spastic paraparesis (HSP) is a group of rare heterogeneous neurodegenerative disorders that share the principal clinical feature of progressive lower limb spastic paralysis. They are classified into pure (pHSP) and complicated (cHSP) forms depending on whether the paraparesis exists alone or in combination with other major clinical features. Cognitive impairment is a frequent feature in cHSP variants and includes the occurrence of mental impairment, dementia, isolated cognitive abnormalities or premature cognitive decline. The aim of the study was to find out if and to which extent a neuropsychological impairment occurs within the different forms of HSP. We evaluated 20 pHSP patients and 11 cHSP patients in comparison to an age-, sex-, and education-matched control cohort. A comprehensive test battery covering a broad range of cognitive functions as well as a screening for dementia was done. Tests were as follows: Digit Span, Block-Span, California Verbal Learning Test, Symbol Digit Modalities Test, Coloured Progressive Matrices, Controlled Oral Word Association Test, and Mini-Mental Status Test. Furthermore, we calculated the brain parenchymal fraction (BPF) from 3-D MRI data in all patients. BPF can specify the presence of global brain atrophy or (in an adapted processing step) changes in the white or the grey matter subfractions. The neuropsychological and the BPF data were correlated. In the pHSP group, significant impairments were observed in memory testing only. Correlation to the MR data showed the screening for attention and dementia. The cHSP patients were characterized by a significantly reduced test performance in comparison to its control group, irrespective of the domain that had been assessed. In addition, nearly all different neuropsychological test modalities showed significant correlations to the BPF and the grey and white matter.
Background Prematurity and its consequences are serious problems that can result in numerous neurosensory disabilities and cerebral cognitive dysfunctions. The Perinatal Risk Index (PERI) might provide a predictive measure of these problems. Aim This study compared the cognitive development of prematurely born children at 4 and 5 years of age with age-matched peers born at term. The secondary objective was to determine whether a correlation exists between perinatal risk and performance on neuropsychological tests among premature children. Methods A total of 54 children between four and five years of age were evaluated; 27 were born very premature (premature group; PG), and 27 were born at term (term group; TG). Executive function, attention, memory, language, visual perception, and spatial structuring were evaluated. Subtests from the Kaufman Assessment Battery for Children, the Rey Complex Figure Test, the McCarthy Scales of Children’s Abilities, the Peabody Picture Vocabulary Test, Test A, Trails A and B, the spatial structuring questionnaire from the Child Neuropsychological Maturity Questionnaire, and the Wechsler Intelligence Scale for Children were used. A PERI score was also obtained for the PG. Results The PG showed significantly lower scores than the TG in all the studied cognitive domains. Visual-perceptive scores were significantly and negatively correlated with the PERI scores of the PG. Conclusions The PG showed neurocognitive deficits compared with the TG. The PERI can be used to predict the development of visual-perceptive abilities in children between four and five years of age.
A multiscale platform has been developed to model lithium ion battery (LIB) electrodes based on the real microstructure morphology. This multiscale framework consists of a microscale level where the electrode microstructure architecture is modeled and a macroscale level where discharge/charge is simulated. The coupling between two scales are performed in real time unlike using common surrogate based models for microscale. For microscale geometry 3D microstructure is reconstructed based on the nano-scale X-ray computed tomography data replacing typical computer generated microstructure. It is shown that this model can predict the experimental performance of LiFePO4 (LFP) cathode at different discharge rates more accurate than the conventional homogenous models. The approach employed in this study provides valuable insight into the spatial distribution of lithium -ion inside the real microstructure of LIB electrodes. The inhomogenous microstructure of LFP causes a wider range of physical and electrochemical properties in microscale compared to homogenous models.
Carbon cryogel (CC) has been prepared through sol–gel polycondensation of resorcinol (R) with formaldehyde (F) followed by freeze-drying and carbonization in this work. The characteristics and lithium-ion insertion–extraction property have been investigated for the first time. Based on the results that CC has very excellent cycling stability but very limited lithium-ion charge–discharge capacity, SiO is employed to synthesize CC–SiO composite by high energy mechanical ball-milling to improve the applicability. The results showed that, CC–SiO is composed of active carbon, graphite, SiO and dispersed Si crystal, while CC is composed of active carbon and graphite. CC–SiO has smaller and much more uniform particles than CC. SiO can greatly improve discharge capacity of CC with an acceptable sacrifice of cycling stability, and the charge–discharge capacity of CC–SiO comes mainly from lithium insertion–extraction in Si–SiO in the sample. CC–SiO has excellent high-rate discharge ability and is promising anode material of lithium-ion battery for use of high power density purpose.
A novel gel polymer electrolyte (GPE), based on poly(methyl methacrylate–acrylonitrile–ethyl acrylate) (P(MMA–AN–EA)) terpolymer, is designed to match LiNi0.5Mn1.5O4 cathode of 5 V lithium ion battery. The performances of the synthesized P(MMA–AN–EA) terpolymer and the corresponding membrane and GPE are investigated by scanning electron microscope, energy dispersive spectroscopy, nuclear magnetic resonance spectra, Fourier transform infrared spectra, thermogravimetric analyzer, electrochemical impedance spectroscopy, linear sweep voltammetry, and charge/discharge test. It is found that the pore structure of P(MMA–AN–EA) membrane is affected by the dose of pore forming agent, polyethylene glycol (PEG400). The membrane with 3 wt% PEG400 presents the best pore structure, in which pores are dispersed uniformly and interconnected, and exhibits the largest electrolyte uptake, resulting in the highest ionic conductivity of 3.82 × 10−3 S cm−1 for the corresponding GPE at room temperature. The GPE has improved compatibility with lithium anode and is electrochemically stable up to 5.2 V (vs. Li/Li+). The high voltage LiNi0.5Mn1.5O4 cathode using the resulting GPE exhibits excellent cyclic stability, maintaining 97.9% of its initial discharge capacity after 100 cycles compared to that of 79.7% for the liquid electrolyte at 0.5 C.
Undesirable side reactions at interface usually ruin the electrode stability and lead to serious self-discharge or decrease the coulombic efficiency. An ionic permeable and electronic insulating amorphous TiO2 passivation could be deposited on the carbon encapsulated LiTi2(PO4)3 electrode through sol-gel method, which drastically enhance the aqueous electrode stability and oxygen tolerance in wide potential window by kinetically suppressing the side reactions at new formed interface. Raman depth profile and SEM have confirmed this surface coating, while nanoelectronic conductivity analysis reveal the TiO2 layer is electronically insulate. The capacity retention of the TiO2 passivated carbon encapsulated LiTi2(PO4)3/LiNO3/LiMn2O4 coin cell for 2000 cycles is 66% assembled in ambient air, which is higher than 55% for the one without TiO2 coating. Electrochemical investigation suggests the TiO2 layer is Li+ ionic conductive, which suppressed the surface water reduction or oxygen reduction reaction. As an interestingly result, the cell stability improvement also benefited from the less degradation of the LiMn2O4 counter electrode. This comprehensive understanding of the electrode passivation using an ionic conductive layer can be potentially applied in other electrochemical devices.
A new nanocomposite of Ge/carbon nanotubes (n-Ge/CNTs) was reported by a facile precursor method through a pyrolysis technique. Among it, germanium nanoparticles are encapsulated with a thin layer of amorphous carbon, which benefits to keep a good electronic contact with carbon nanotubes. Germanium nanoparticles are mainly supported inside the carbon nanotubes, which can effectively buffer the volume changes of Germanium. The composite was an effectively mixed (Li+ and e−) conducting network, which is vital to a quick Li insertion. The composite was shown to exhibit a reversible capacity of about 750mAhg−1 (74.4mAg−1) and an improved rate performance, compared with that of CNTs processed as the same condition. Our results demonstrated the composite to be a good active Li-storage material for Li batteries.
The carbon-coated TiO2 (TiO2@C) and FeTiO3 (TiO2/FeTiO3@C) hybrid porous microspheres with a specific surface area of 35.1 m2g−1 have been successfully synthesized by carbonizing the mixture of pyrrole with lab-made TiO2/Fe2O3 porous microspheres. The as-prepared TiO2/FeTiO3@C porous electrode material possessed a reversible capacity of 441.5 mAh g−1 after 300 cycles at a current density of 100mAg−1 and a coulombic efficiency of 99%. Comparing with TiO2, TiO2@C, and TiO2/Fe2O3 porous microspheres, the TiO2/FeTiO3@C porous composites exhibited superior cycling and rate performances, which are rooted in the synergistic effect that generated by little volume variation of TiO2 matrix, high capacity of FeTiO3 and good electrical conductivity of carbon coating (with a thickness of 2–5nm deposited on the surface and inner wall of pores) during the charge/discharge processes.