batterydata/paper-abstracts huggingface dataset:
The outcome of first episode psychosis (FEP) is highly variable and difficult to predict. We studied prospectively the impact of poor insight and neuropsychological deficits on outcomes in a longitudinal cohort of 127 FEP patients. Participants were assessed on 5 domains of cognitive function and 2 domains of insight (clinical and cognitive). At 12months, patients were assessed again for symptom severity and psychosocial function. Regression analyses revealed that cognitive insight (a measure of self-reflectiveness and self-certainty) was the best baseline predictor of overall psychopathology at 12months whereas executive function performance at admission to the study indicated later severity of negative symptoms. Other neuropsychological and insight measures were poor predictors of psychosocial function at 1year. The results suggest that specific neuropsychological and insight factors have separate predictive capacities indicating that they are distinct psychological processes in psychosis. Cognitive insight proved to be a useful prognostic indicator, and should be considered for future studies and as a potential focus for treatment.
Micron-size Si anode is notorious for having extremely poor cycle life. It is mainly caused by the large volume change (∼300%) and poor mechanical strength of the Si electrode. Satisfying methods to address this issue are seriously lacking in literature. In this study, novel single-layer, double-layer and triple-layer asymmetric membranes containing micron-size silicon have been fabricated using a simple phase inversion method to dramatically improve its cyclability. The electrochemical performance of these asymmetric membranes as lithium ion battery anodes are evaluated and compared to pure micron-size Si powders and carbonaceous asymmetric membranes. All three types of asymmetric membrane electrodes demonstrate significantly enhanced stability as compared to pure Si powders. The single-layer asymmetric membrane has the largest capacity degradation due to the loss of pulverized Si powders from the membrane surface, only 40% of whose capacity can be retained in 100 cycles. But this performance is still much better than pure micron-size silicon electrode. After being coated with nanoporous carbonaceous layers on both sides of a single-layer asymmetric membrane to make a triple-layer asymmetric membrane (sandwich structure), the capacity retention is notably increased to 88% in 100 cycles at 610mAhg−1 and 0.5C. The enhanced stability is attributed to the extra nanoporous coatings that can prevent the fractured Si powders from being leached out and allow facile lithium ion diffusions. Such a novel, efficient and scalable method may provide beneficiary guidance for designing high capacity lithium ion battery anodes with large volume change issues.
Low-cost, layered transition-metal dichalcogenides (MX2) based on molybdenum and tungsten have attracted substantial interest as alternative catalysts for the hydrogen evolution reaction (HER). These materials have high intrinsic per-site HER activity; however, a significant challenge is the limited density of active sites, which are concentrated at the layer edges. Here we unravel electronic factors underlying catalytic activity on MX2 surfaces, and leverage the understanding to report group-5 MX2 (H-TaS2 and H-NbS2) electrocatalysts whose performance instead mainly derives from highly active basal-plane sites, as suggested by our first-principles calculations and performance comparisons with edge-active counterparts. Beyond high catalytic activity, they are found to exhibit an unusual ability to optimize their morphology for enhanced charge transfer and accessibility of active sites as the HER proceeds, offering a practical advantage for scalable processing. The catalysts reach 10 mA cm−2 current density at an overpotential of ∼50–60 mV with a loading of 10–55 μg cm−2, surpassing other reported MX2 candidates without any performance-enhancing additives.
Spinel Li[Li(1−x)/3Cr x Ti(5−2x)/3]O4 compounds have been investigated as anode materials for lithium secondary batteries. Li[Li(1−x)/3Cr x Ti(5−2x)/3]O4 electrodes (0≤x≤1.0) exhibit a reversible capacity between 163 and 154mAhg−1 with excellent cycleability. Increase in the amount of Cr ions substituted for Ti ions in the spinel structure decreases the reversible capacity due to a smaller theoretical capacity, but lowers the area specific impedance (ASI) and increases the rate capability.
Composites of carbon nanotubes and conducting polymers can be prepared via chemical synthesis, electrochemical deposition on preformed carbon nanotube electrodes, or by electrochemical co-deposition. The composites combine the large pseudocapacitance of the conducting polymers with the fast charging/discharging double-layer capacitance and excellent mechanical properties of the carbon nanotubes. The electrochemically co-deposited composites are the most homogeneous and show an unusual interaction between the polymer and nanotubes, giving rise to a strengthened electron delocalisation and conjugation along the polymer chains. As a result they exhibit excellent electrochemical charge storage properties and fast charge/discharge switching, making them promising electrode materials for high power supercapacitors.
Considerable efforts have been devoted to developing sodium-ion batteries for large-scale energy storage due to the high abundance and low cost of sodium resources. However, the inferior cyclability and reaction kinetics of electrodes toward sodium ions still impedes their further development. In this study, we designed a two-dimensional (2D) composite where ultrafine CoSe nano-crystallites were confined in N-doped carbon (CoSe/NC-L) to attain excellent cycling performance and fast sodium ion storage. The CoSe/NC-L was successfully prepared through a high-temperature reaction of leaf-like Co-based ZIF (ZIF-L) and Se powder. It is demonstrated that the particle size of Se powder plays an important role in the formation of ultrafine CoSe nano-crystallites and encapsulated configuration. The combined merits of ultrafine CoSe and encapsulation into 2D NC matrix effectively enhance reaction kinetics, accommodate volume change expansion of CoSe and inhibit the formation of unstable SEI. Therefore, the CoSe/NC-L composite displayed high initial specific capacity of 530 mAh g−1 and Coulombic efficiency of 67.2% at 0.2 A g−1. Notably, superior capacity retention of 82.2% with stable Coulombic efficiency of 97.0% is achieved at 0.5 A g−1 after 150 cycles in NaClO4 electrolyte system. This work casts a new light on the smart design of metal selenide electrode materials for sodium ions batteries.
Selective transformation of one-carbon (C1) molecules, which are abundant or easily available and inexpensive carbon feedstocks, into value-added multi-carbon (C2+) compounds is a very attractive but highly challenging research target. Photocatalysis and electrocatalysis have offered great opportunities for the activation and controllable C–C coupling of C1 molecules under mild and environmentally benign conditions. This article provides a critical review on recent advances in photocatalytic and electrocatalytic conversions of major C1 molecules, including CO, CO2, CH4, CH3OH and HCHO, into C2+ compounds, such as C2H4, C3H6, ethanol and ethylene glycol, which play essential roles in the current chemical or energy industry. Besides the photocatalysts and electrocatalysts reported for these conversions, the structure–performance relationships and the key factors that control the activity and product selectivity are analysed to provide insights into the rational design of more efficient catalysts for the synthesis of C2+ compounds from C1 feedstocks. The active species, reaction intermediates and reaction or catalyst-functioning mechanism are discussed to deepen the understanding of the chemistry for the activation and selective C–C coupling of C1 molecules in the presence of solar energy or electrical energy.
In the conventional vanadium redox flow battery, the bipolar plates are usually designed with flow fields to improve the battery performance by facilitating the homogeneous distribution of electrolytes. The introduction of flow field results in severer oxidation corrosion, owing to the sharp edges and corners formed on the flow fields. In this study, a modified battery structure for the vanadium redox flow battery is proposed to alleviate the oxidation corrosion of the bipolar plates and flow fields. The flow fields are segmented from the bipolar plates, and inserted between the porous electrodes and membrane as independent components. To improve the service life and processability, the flow fields are prepared with photosensitive resin by means of the three-dimensional printing technique. A battery with the modified structure is assembled to examine the battery performance and oxidation resistance. Morphology characterization and elemental composition analysis are employed to investigate the oxidization on the bipolar plate surface. The modified battery structure contributes to decreasing the contact resistance. The pressure drop and charging/discharging tests indicate that the battery with the modified structure exhibits maintained flow behavior and energy efficiency, and provides a higher Coulombic efficiency compared to the conventional vanadium redox flow battery. Moreover, the bipolar plates in the modified battery structure demonstrate a higher capacity to restrain oxidation corrosion during the charging process. The modified battery structure can enhance the service life of bipolar plates and flow fields, and is significant in the application of vanadium redox flow battery.
The enhancement of energy density at high power density is highly desired in design of supercapacitor, which relies on the electrochemically accessible electrode area, electrons/ions diffusion channels of electrodes and the device assembly manner. Herein, graphitized and porous fullerene carbon soot is used as matrix for preparation of activated carbon (denoted as a-FC). The high specific surface area, hierarchical pore sizes and moderate graphitization degree of a-FC enable balanced specific capacitance, rate capability and cycleability. Meanwhile, graphene-Co3O4 composite (GC) with cross-linked porous Co3O4 nanofibers array onto graphene sheet is hydrothermally deposited on Ni foam substrate. The pseudocapacitive GC electrode can offer superior capacitance (1935 F g−1 at 5 A g−1), rate capability (68% capacitance retaining ratio within 0.5–50 A g−1) and considerable cycleability (17% capacitance decline within 2000 charge-discharge cycles) comprehensively. Furthermore, the asymmetric supercapacitor based on the a-FC and GC electrodes delivers balanced energy density (50.3–20.9 Wh kg−1), power density (786–12128 W kg−1) and cycleability (77% initial capacitance maintaining ratio within 5000 charge-discharge cycles), highlighting the potential in efficient energy storage device.
Publisher Summary This chapter discusses the most promising constituents of solid-oxide fuel cells, their advantages and shortcomings, and then the perspectives and the potential to develop advanced materials and better devices. The chapter focuses on the general electrochemical problems. The most important step is searching for sufficiently stable and mechanically strong structures that exhibit promising potential in terms of electrochemistry, such as fluorites, perovskites, pyrochlore,s or brownmillerites, in the case of electrolyte materials. In conventional fuel-cell designs, the electrolyte not only mediates the electrochemical reactions taking place at the anode and cathode, but also separates the fuel from the oxidant to prevent direct combustion.
We report a novel magnetic field assisted chemical reduction method for the synthesis of boron-doped Ni/Fe nano-chains as promising catalysts for the oxygen evolution reaction (OER). The boron-doped Ni/Fe nano-chains were synthesised in a one step process at room temperature using NaBH4 as a reducing agent. The addition of boron reduced the magnetic moment of the intermediate synthesis products and produced nano-chains with a high specific surface area of 73.4 m2 g−1. The boron-doped Ni/Fe nano-chains exhibited catalytic performance superior to state-of-the-art Ba0.5Sr0.5Co0.8Fe0.2O3−δ perovskite and RuO2 noble metal oxide catalysts. The mass normalized activity of the boron-doped Ni/Fe nano-chains measured at an overpotential of 0.35 V was 64.0 A g−1, with a Tafel slope of only 40 mV dec−1. The excellent performance of the boron-doped Ni/Fe nano-chains can be attributed to the uniform elemental distribution and highly amorphous structure of the B-doped nano-chains. These results provide new insights into the effect of doping transition-metal based OER catalysts with non-metallic elements. The study demonstrates a facile approach to prepare transition metal nano-chains using magnetic field assisted chemical reduction method as cheap and highly active catalysts for electrochemical water oxidation.
The main aim of the present study was to compare volume differences in the hippocampus and parahippocampal gyrus as biomarkers of Alzheimer’s disease (AD). Based on the previous findings, we hypothesized that there would be significant volume differences between cases of healthy aging, amnestic mild cognitive impairment (aMCI), and mild AD. Furthermore, we hypothesized that there would be larger volume differences in the parahippocampal gyrus than in the hippocampus. In addition, we investigated differences between the anterior, middle, and posterior parts of both structures. We studied three groups of participants: 18 healthy participants without memory decline, 18 patients with aMCI, and 18 patients with mild AD. 3 T T1-weighted MRI scans were acquired and gray matter volumes of the anterior, middle, and posterior parts of both the hippocampus and parahippocampal gyrus were measured using a manual tracing approach. Volumes of both the hippocampus and parahippocampal gyrus were significantly different between the groups in the following order: healthy > aMCI > AD. Volume differences between the groups were relatively larger in the parahippocampal gyrus than in the hippocampus, in particular, when we compared healthy with aMCI. No substantial differences were found between the anterior, middle, and posterior parts of both structures. Our results suggest that parahippocampal volume discriminates better than hippocampal volume between cases of healthy aging, aMCI, and mild AD, in particular, in the early phase of the disease. The present results stress the importance of parahippocampal atrophy as an early biomarker of AD.
Nafion-coated polypropylene separator (Celgard 2500) is used as cation-selective membrane for lithium sulfur batteries to suppress polysulfide diffusion enhancing the charge efficiency of the cells especially at low charge/discharge rates. The charge efficiency of the 10th cycle rises from about 70% to nearly 90% at a rate of C/20. The reduction of polysulfide penetration through the Nafion-coated Celgard 2500 is also proven by visual characterization. FTIR and SEM investigations verify a smooth and dense Nafion-coating on the porous polypropylene backbone of the separator. The influence of Nafion-loading on rate capability and discharge voltage is investigated by galvanostatic charge–discharge measurements. With the lowest Nafion-loading of 0.25 mg cm−2 we are able to achieve a rate capability comparable to uncoated Celgard 2500 up to current densities of 3 mA cm−2, whereas the functionality as polysulfide shuttle inhibitor is largely preserved.
A fundamental requirement for a renewable energy generation technology is that it should produce more energy during its lifetime than is required to manufacture it. In this study we evaluate the primary energy requirements of a prospective renewable energy technology, solar-driven photoelectrochemical (PEC) production of hydrogen from water. Using a life cycle assessment (LCA) methodology, we evaluate the primary energy requirements for upstream raw material preparation and fabrication under a range of assumptions of processes and materials. As the technology is at a very early stage of research and development, the analysis has considerable uncertainties. We consider and analyze three cases that we believe span a relevant range of primary energy requirements: 1550 MJ m−2 (lower case), 2110 MJ m−2 (medium case), and 3440 MJ m−2 (higher case). We then use the medium case primary energy requirement to estimate the net primary energy balance (energy produced minus energy requirement) of the PEC device, which depends on device performance, e.g. longevity and solar-to-hydrogen (STH) efficiency. We consider STH efficiency ranging from 3% to 10% and longevity ranging from 5 to 30 years to assist in setting targets for research, development and future commercialization. For example, if STH efficiency is 3%, the longevity must be at least 8 years to yield a positive net energy. A sensitivity analysis shows that the net energy varies significantly with different assumptions of STH efficiency, longevity and thermo-efficiency of fabrication. Material choices for photoelectrodes or catalysts do not have a large influence on primary energy requirements, though less abundant materials like platinum may be unsuitable for large scale-up.
The economical operation of many distributed energy assets relies on effective on-line control, which in turn often requires forecasts to be made. To produce and evaluate forecasts, the error metric by which one measures forecast accuracy must be selected. A new method is presented which customizes a forecast error metric to a given on-line control problem instance, in order to improve the controller's performance. This method is applied to the real-time operation of a battery with the objective of minimizing the peak power drawn by an aggregation of customers over a billing period. In the empirical example considered, customizing the forecast error metric to each problem instance, improved performance by 45% on average, compared to a controller provided with a forecast of the same type, but trained to minimize mean-squared-error. Error metric customization is made possible by two newly proposed parametrized error metrics. The proposed method can be applied to any on-line optimization problem which requires a point forecast as an input, and which can be accurately simulated ahead of time. The method is likely to be most effective in applications where forecasting errors are quite high, as in these applications the choice of forecast error metric significantly affects the forecasts which are produced.
This study develops a driving system for an electrowetting-on-dielectric (EWOD) device comprising a 9 V battery, an ATmega8535 microprocessor, a DC/DC converter, two regulator ICs and a switch circuit. The driving system greatly improves the portability of the EWOD device and is capable of generating a square wave with voltages ranging from 50~100 Vpp and frequencies in the range 1~5 kHz. A series of experimental and numerical investigations are performed to investigate the effect of the conducting electrode geometry on the droplet velocity in the EWOD device. Three different electrode configurations are considered, namely a linear array of square electrodes, a series of interdigitated electrodes having either two or three fingers, and a series of interdigitated electrodes having five or six fingers. The experimental results show that the corresponding droplet velocities are 7.25 mm/s, 8.17 mm/s and 7.82 mm/s, respectively. The simulation results indicate that the pressure difference induced within the droplets actuated by the square, interdigitated (2323) and interdigitated (5656) electrodes has a value of 15.5 N/m2, 262 N/m2 and 141.1 N/m2, respectively. The corresponding droplet velocities are 33.8 mm/s, 72.7 mm/s and 64.5 mm/s, respectively. Overall, the experimental and numerical results indicate that the interdigitated (2323) electrode optimizes the transportation of the droplets in the EWOD device. The improved droplet velocity obtained using this particular electrode configuration is attributed to an increased length of the contact line between the droplet and the actuating electrode, which in turn increases the driving force.
Four months of daily nutrient and radon (a natural groundwater tracer) observations at the outlet of a heavily drained coastal wetland illustrated how episodic floods and diffuse groundwater seepage influence the biogeochemistry of a sub-tropical estuary (Richmond River, New South Wales, Australia). Our observations downstream of the Tuckean Swamp (an acid sulphate soil floodplain) covered a dry stage, a flood triggered by a 213-mm rain event and a post-flood stage when surface water chemistry was dominated by groundwater discharge. Significant correlations were found between radon and ammonium and N/P ratios and between radon and dissolved organic nitrogen (DON) during the post-flood stage. While the flood lasted for 14 % of the time of the surface water time series, it accounted for 18 % of NH4, 32 % of NOx, 66 % of DON, 58 % of PO4 and 55 % of dissolved organic phosphorus (DOP) catchment exports. Over the 4-month study period, groundwater fluxes of 35.0, 3.6, 36.3, 0.5 and 0.7 mmol m−2 day−1 for NH4, NOx, DON, PO4 and DOP, respectively, were estimated. The groundwater contribution to the total surface water catchment exports was nearly 100 % for ammonium, and <20 % for the other nutrients. Post-flood groundwater seepage shifted the system from a DON to a dissolved inorganic N-dominated system and doubled N/P ratios in surface waters. We hypothesise that the Richmond River Estuary N/P ratios may reflect a widespread trend of tidal rivers and estuaries becoming more groundwater-dominated and phosphorus-limited as coastal wetlands are drained for agriculture, grazing and development.
The structure of the highly durable silicon-based anode prepared by electrodeposition was investigated for volume change and chemical structure. With repeated charge–discharge cycles, the volume change resulting from the anode film thickness decreased, and, after 100 cycles, essentially no difference was observed between the charged and discharged states. The buffering effect of the volume change was considered to be achieved by the formation of Li2O, Li2CO3, and lithium silicates such as Li4SiO4, whose existence were supported by STEM, EELS, and XPS analyses. From the structural analyses, the main reactions related to the capacity of the silicon-based anode were considered to be the formation of Li x Si and Li2Si2O5. Li x Si and Li2Si2O5 can be delithiated into Si and SiO2, respectively.
Lithium–sulfur (Li–S) batteries are great candidates for energy storage systems, but need to overcome the issues of low sulfur utilization and polysulfide shuttling for use in large-scale commercial applications. Recently, quaternized polymers have received much attention for their polysulfide trapping properties due to electrostatic interaction. In this work, we report a series of polyarylether sulfone (PSF) binders with different cation structures including imidazolium (Im), triethylammonium (Tr), and morpholinium (Mo). The ability of the these quaternized binders and the conventional poly(vinylidene fluoride) or PVDF binder to capture polysulfide increases in the order of PVDF << PSF-Mo < PSF-Tr< PSF-Im. The delocalized charge on the imidazolium cation may promote the interaction between PSF-Im and polysulfide as indicated by an X-ray photoelectron spectroscopic study. The PSF-Im based cathodes showed the highest capacity retention (77% at 0.2 C after 100 cycles and 84% at 0.5 C after 120 cycles), and the best rate capability. This work demonstrates the importance of the cation structure in the design of efficient quaternized binders for high performance Li–S batteries.