batterydata/paper-abstracts huggingface dataset:
Red phosphorus (P) represents one kind of high-capacity anodes for lithium ion batteries. Practical application of red P is primarily limited by its low conductivity, severe volume expansion and consequent sluggish electrode kinetics. Herein, we propose a P-TiO2@CNT composite with TiO2-modified red P nanosheets well entangled in carbon nanotube (CNT) network. The co-incorporation of amorphous TiO2 and CNT can synergistically provide dual accommodation to red P, which not only allow its lithiation and volume expansion to exhibit high capacities, but also buffer the stress during red P expansion and avoid structural destruction. Meanwhile, the CNTs support a highly conductive skeleton and porous framework in the composite, which continuously provides high conductivity and creates more active sites for lithium storage during repeated electrochemical reactions. The P-TiO2@CNT electrode exhibits impressive cycling stability (87% capacity retention in 200 cycles at 0.2 A g−1) and excellent rate capability (750 mAh g−1 at 10 A g−1), making it a promising anode material for high-capacity and high-rate lithium-ion batteries.
Ternary metal vanadium oxides have been considered as potential anode materials for lithium-ion batteries (LIBs). However, the poor electronic conductivity and large volume expansion during the discharge/charge process lead to poor electrochemical performance. Herein, we firstly report the preparation of grass-like Zn3V3O8 nanobelts array coated 3D carbon fiber cloth (Zn3V3O8/CFC) as a binder-free anode for LIBs. The composites could effectively improve the kinetics of electronic transportation and mitigate the volume expansion of electrodes during discharge/charge process. As a result, the Zn3V3O8/CFC exhibits excellent Li+ storage properties. It can deliver a reversible capacity of ∼1750mAhg−1 at a low current density of 100mAg−1 and a specific capacity of 942mAhg−1 at the high rate of 1.5Ag−1. Even measured at high current density of 5Ag−1, the electrode could maintain a high capacity of 455mAhg−1 after 500 cycles with a capacity retention of 82.7%.
The aim of this study was to assess the effect of dopaminergic treatment on emotional memory in patients with Parkinson’s disease (PD). We tested memory for emotional and neutral visual stimuli in ten non-demented PD patients on and off dopaminergic medication. Patients recalled significantly more emotional items during the off- than on-medication testing session. In contrast, treatment condition did not affect memory for neutral items. These findings demonstrate that emotional memory deficits observed in PD may result from dopaminergic treatment and suggest an involvement of dopaminergic neurotransmission in emotional processing.
The atomic structural and electrochemical properties of Fe substituted nano porous LiMn1-xFexPO4 (x = 0–0.8) composites are investigated and compared. X-ray scattering method is used for atomic structural investigation. Rietveld refinement shows that all Fe substituted composites have the same olivine structure (Pnma) with lithium occupying octahedral 4a sites, Fe2+ replacing Mn2+ at the octahedral 4c sites. The a, b, c parameters and cell volume decrease with the addition of Fe2+. When the nano porous LiMn1-xFexPO4 composites are evaluated as cathode materials in lithium cells at room temperature, x = 0.6, and 0.8 resulted in the best overall electrochemical performance, exhibiting stable cycling and high discharge capacities of 149 and 154 mA h g−1, respectively. The composites with above x = 0.4 show a fast lithium ions transfer with high electronic conductivity because Fe transition metal substitution reduce the partly occupation of Mn in the M1 (LiO6) sites and thereby Mn block the lithium ion diffusion pathway. We here firstly find the antisite defect in the high Mn content in porous LiMn1-xFexPO4 composites.
The promises of nanotechnology have been framed by a variety of metaphors, that not only channel the attention of the public, orient the questions asked by researchers, and convey epistemic choices closely linked to ethical preferences. In particular, the image of the ‘therapeutic missile’ commonly used to present targeted drug delivery devices emphasizes precision, control, surveillance and efficiency. Such values are highly praised in the current context of crisis of pharmaceutical innovation where military metaphors foster a general mobilization of resources from multiple fields of cutting-edge research. The missile metaphor, reminiscent of Paul Ehrlich’s ‘magic bullet’, has framed the problem in simple terms: how to deliver the right dose in the right place at the right moment? Chemists, physicists and engineers who design multi-functional devices operating in vitro can think in such terms, as long as the devices are not actually operating through the messy environment of the body. A close look at what has been done and what remains to be done suggests that the metaphor of the “therapeutic missile” is neither sufficient, nor even necessary. Recent developments in nanomedicine suggest that therapeutic efficacy cannot be obtained without negotiating with the biological milieu and taking advantage of what it affords. An ‘oikological’ approach seems more appropriate, more heuristic and more promising than the popular missile. It is based on the view of organism as an oikos that has to be carefully managed. The dispositions of nanocapsules have to be coupled with the affordances of the environment. As it requires dealing with nanoparticles as relational entities (defined by their potential for interactions) rather than as stable substances (defined by intrinsic properties) this metaphor eventually might well change research priorities in nanotechnology in general.
In Linehan’s (1993) biosocial theory, borderline personality disorder (BPD) results in part from frequent, intense, negative emotions and maladaptive behavioral responses to those emotions. We conducted a secondary data analysis of an intensive single-case experimental design to explore hourly relations among behavioral responses and emotions in BPD. Eight participants with BPD (Mage = 21.57, 63% female; 63% Asian-American) reported their emotions and behaviors hourly on two days. Participants reported a neutral-to-negative average emotional state with substantial variability each day. This emotional state was characterized most frequently by anxiety and joy. Participants tended to “dig into”, or savor, experiences of joy, but problem-solve around, push away, or accept anxiety. Acceptance predicted hour-by-hour increases in negative emotion intensity, and pushing emotions away predicted hour-by-hour increases in positive emotion intensity. These results suggest that anxiety dominates the emotional experiences of people with BPD and co-occurs with a variety of emotion regulation strategies, while joy co-occurs with strategies designed to prolong emotional experiences. Despite its general adaptiveness, acceptance may be less effective, and pushing emotions away may be more effective, than other emotion regulation strategies at improving momentary negative emotions for those with BPD. We discuss the preliminary nature of these findings and encourage future researchers to build on them in larger samples with more severe presentations of BPD.
The present study aims at assessing the applicability of porous metals to the electrodes of electric double layer capacitors (EDLC). Porous Ni materials for test electrodes were prepared from commercially available Ni–Al alloys through an alkali-leaching process and the subsequent dry and surface-treatment processes. The surface area and pore structure (mesoporous structure) have been found to depend on the class of the alloys. Furthermore, the porous Ni materials prepared via the dry processes with heating and with exposure to air have shown high electrochemical stability but quite low capacitance. In contrast, the dry process without heating and in no contact with air has made the surface and bulk sate electrochemically more active, which induces pseudocapacitance as well as double-layer capacitance. The pseudocapacitive reaction is responsible for the gradual modification of the active electrode to a high-resistance material with charge/discharge cycles. The volumetric total capacitance has reached as high as 31.9F/cm3 (in a three-electrode system) irrespective of not so high specific surface areas (SSA) of 43m2/g. At present, the capacitance is lower than the values, i.e., 40.3–78.0F/cm3, of the commercial microporous active carbons with the high SSAs of 1508–2164m2/g. However, the capacitance normalized by the surface areas has reached 10.2μF/cm2, which is beyond 3.6–6.6μF/cm2 of the active carbons. In addition, the mesoporous Ni electrodes have shown more favorable rate performance than the microporous active carbons due to the low ion-transfer resistance.
Whether FeF3 can take active part in electrochemical reaction is largely determined by its conductivity, which can be affected by the band gap and crystallite dimension. In this communication, the density of states (DOS) of FeF3 and Ti-doped FeF3 were calculated using a first principle density functional theory (DFT). Moreover, crystalline size was calculated according to Debye-Scherrer Equation. The results indicate that Ti-doping can reduce the band gap and impact the microcrystal growth of FeF3 at the same time. Both effects work synergistically on capacity loss and cycling stability; while impact antagonistically on charge transfer resistance (R ct), Li+ diffusion coefficient (DLi +) and specific capacity, leading to the excellent electrochemical performances of Fe(1−x)Ti x F3/C. The Fe0.99Ti0.01F3/C nanocomposite achieves an initial capacity of 219.8mAh/g and retains a discharge capacity of 173.6mAh/g after 30 cycles at room temperature in the voltage range of 2.0–4.5V. The hysteresis of discharge voltage plateau is significantly mitigated as well. In addition, the three-electron reaction of Fe0.99Ti0.01F3/C during 1.0–4.5V exhibits a high initial specific discharge capacity of 764.6mAh/g. This study suggests that not only the band gap, but also the microcrystalline structure can be changed by Ti-doping, both of which have remarkable effects on the electrochemical properties, providing a new perspective on the effect of cation dopant.
After treatment in different Fenton's reagents, chemical changes in Nafion® membranes were analyzed by X-ray photoelectron spectroscopy (XPS) and clear evidence of polymer degradation was observed. Exposure of the membrane to 2h of X-ray radiation did not affect the chemical structure of the membrane. However, treatment with various Fenton's reagents indicated that the (CF2) n polymer backbone had decomposed. Fluorine and sulfur XPS peak intensity decreases were consistent with the detection of fluoride and sulfate ions during fuel-cell tests. The increase in oxygen atom concentration suggests that oxygen-rich moieties formed in the membrane. These results indicated that in addition to degradation of the polymer side chain, chemical attack of the CF2 backbone may be the primary reason for extensive fluorine loss and hydrogen crossover in membranes after long-term operation. FTIR spectra showed the formation of CO and S–O–S in the degraded membrane. Two degradation schemes consistent with the results observed have been proposed. Under the same experimental conditions, no detectable changes in XPS spectra were found between a fresh membrane electrode assembly (MEA) and an MEA after long-term operation. These results suggest that degradation occurred mainly within the membrane or at the membrane-electrode interface.
Si/C/TiO2 composite nanofibers have been prepared via a facile electrospinning method combined with a sol–gel chemistry, whose electrochemical performance as anode materials in lithium-ion battery was evaluated. As-prepared nanofibers (NFs) were characterized using scanning electron microscopy, energy dispersive spectroscopy, powder X-ray diffraction and thermogravimetric analyzer to identify their morphology, phase, crystallinity and compositions. Rutile phase TiO2 nanofibers demonstrated a relatively low gravimetric specific capacity of ∼83 mAh g−1 when discharged at 0.1C. In contrast, composite nanofibers possess a much higher gravimetric specific capacity. When the Si to C mass ratio is of 0.217, a specific capacity as high as 720 mAh g−1 can be attained, 94% of which can be maintained after 55 cycles. The enhanced cycling stability of micron silicon materials is attributed to the space confinement provided by the structurally stable TiO2. These findings can provide a beneficial guidance for future lithium ion battery electrode development.
Thus, laccases and/or laccase-mediator systems find potential applications in bioremediation, paper pulp bleaching, finishing of textiles, bio-fuel cells and more. Significantly, laccases can be used in organic synthesis, as they can perform exquisite transformations ranging from the oxidation of functional groups to the heteromolecular coupling for production of new antibiotics derivatives, or the catalysis of key steps in the synthesis of complex natural products. In this review, the application of fungal laccases and their engineering by rational design and directed evolution for organic synthesis purposes are discussed.
Nickel hydroxide powder was modified by immersing the mixture of nickel hydroxide powder with cobalt compounds in an alkali solution or by chemical deposition. Electrochemical properties of the pasted nickel electrodes consisting of surface modified Ni(OH)2 powder in a porous nickel substrate were studied. The results show that the active material utilization of the modified nickel electrodes greatly increases due to the uniform distribution of a Co(OH)2 layer on the surface of the nickel hydroxide powder resulting in the improvement of the electrochemical activity and conductivity. The EIS results show that the Co(OH)2 layer decreases the charge-transfer resistance and increases the active surface area of the nickel electrode.
We report a simple yet efficient method to synthesize phosphorus- and nitrogen-co-doped glucose-derived microporous carbons with a simple inorganic salt (ammonium phosphate) as the single phosphorus and nitrogen source. The obtained products are typical microporous carbons with low surface area and narrow pore size distribution. The doping amount of oxygen, nitrogen, and phosphorus and the population of various functionalities were not only temperature-dependent, but also correlated with each other. The resultant samples exhibit a specific capacitance of 183.8 F g−1, a capacitance retention ratio of over 90%, and an operating voltage up to 1.4 V in an alkaline electrolyte of 6 M KOH. The promising electrochemical performances can be attributed to the synergetic effect of (1) pseudocapacitance that originated from rich and tunable surface group by co-doping of phosphorus and nitrogen; and (2) the electric double layer capacitance that came from the uniform porosities developed by in situ activation.
A facile scalable synthesis of hierarchical Sb/C micro-/nanohybrid has been addressed in this work, which possesses the advantages of both micrometer and nanometer scale structures as lithium-ion battery anode. Difunctional methacrylate monomers are used as solvent and carbon source as well. Liquid precursor of antimony(III) n-butoxide is dissolved in the resin monomer solution, and further incorporated into the cross-linking polymer network via photo polymerization. Through calcination in argon/hydrogen atmosphere, antimony nanoparticles are in situ formed by carbothermal reduction, and homogeneously embedded in the in situ formed micrometer sized carbon matrix. The morphology, structure, crystallinity, spatial dispersion, composition, and electrochemical performance of the Sb/C micro-/nanohybrid are systematically investigated. The cyclic and rate performance of the Sb/C micro-/nanohybrid anode have been effectively improved compared to the pure carbon anode. A reversible capacity of 362 mAh g−1 is achieved with a reasonable mass loading density after 300 cycles at 66 mA g−1, corresponding to capacity retention of 79%. With reducing mass loading density, the reversible capacity reaches 793 mAh g−1 after 100 cycles. Moreover, the electrochemical performance of Sb/C micro-/nanohybrid as sodium-ion battery anode is also investigated in this study.
Lithium-air batteries have become appealing in recent years, but one of the major challenges is the large overpotential associated with the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Tremendous efforts have been made on developing highly active and durable catalysts to lower the overpotentials for ORR and OER. In addition to the intrinsic activity and stability of the catalysts, construction of the air electrodes plays an important role in the overall performance of the air electrodes. Accordingly, three kinds of electrode configurations are herein compared: single, combined, and decoupled bifunctional air electrodes. The decoupled design of the air electrodes shows the best performance in terms of both the discharge and charge performance compared to the other configurations.
The study describes a stand-alone photovoltaic system in which the storage is realized using electrolytic hydrogen, converted into electricity in fuel cells. The aim of the research is the optimization of the sizing of the system elements chain (photovoltaic generator, electrolyzer, tank, fuel cell) with respect to the electric load to fulfil. A positive annual balance between hydrogen production and consumption must be guaranteed; furthermore, energy production surplus that cannot be stored or converted into hydrogen due to batteries or tanks capacity limits must be avoided. The energetic analysis and that of hydrogen production and consumption have been carried out on an hourly basis using the HOMER software. The study shows that, being the load active in the evening and the system disconnected from the grid, excess energy cannot be exploited unless large tanks are used, if high gas pressures are to be avoided. Consequently, the system use in public areas or residential buildings, where visual impact generated by tanks is hardly acceptable and safety rules do not allow high gas pressures, is advisable only in grid-connected configurations. Such problems are by far reduced when a marked self consumption is present.
Similar to carbonaceous materials, porous metal oxides have attracted wide attention in energy storage and conversion systems because of their structural advantages, including high activity and electrolyte accessibility. In this work, we report the novel preparation of porous vanadium pentoxide (V2O5) as high performance cathode material for lithium ion batteries. Ketjen black (KB), a porous carbon material, has been employed as hard templates to host precursor species in their porous structures. The porous V2O5 electrode material is prepared after removing the KB carbon framework by calcinating the composites in air. As cathode materials for lithium ion batteries, the porous V2O5 electrodes exhibit high capacity, good cycling stability and rate capability. An initial discharge capacity of 141.1 mA h g−1 is delivered at a current density of 100 mAg−1, very close to the theoretical capacity of 147 mA h g−1.
A semi-solid flow battery, consisting in a single channel with millimetric width, was operated in flow conditions using Li4Ti5O12 (LTO) or LiNi1/3Co1/3Mn1/3O2 (LNCM) based suspensions versus Li metal. Cell voltages were measured experimentally for various values of charge/discharge current. A model of the electrochemical cell was developed and validated by comparing calculated results with experimental data. The model consists in solving simultaneously the suspension rheology, potential and current within the cell (secondary distribution) and state of charge evolution between the inlet and outlet. Modelling results indicate low pressure drop (<50 kPa), nearly-homogeneous velocity profile along the channel and potential and current gradients in the cell. Comparison of experimental and calculated results indicate that the model takes into account the influence of applied current density on the cell potential but with significant differences on their absolute value, which are discussed in terms of electrochemical stability for the semi-solid suspensions during cycling. Results detailed in this article can, therefore, be applied to larger electrochemical cells or systems based on alternative chemistries, operated in flow conditions.
A viable hydrogen economy has thus far been hampered by the lack of an inexpensive and convenient hydrogen storage solution meeting all requirements, especially in the areas of long hauls and delivery infrastructure. Current approaches require high pressure and/or complex heat management systems to achieve acceptable storage densities. Herein we present a manganese hydride molecular sieve that can be readily synthesized from inexpensive precursors and demonstrates a reversible excess adsorption performance of 10.5 wt% and 197 kgH2 m−3 at 120 bar at ambient temperature with no loss of activity after 54 cycles. Inelastic neutron scattering and computational studies confirm Kubas binding as the principal mechanism. The thermodynamically neutral adsorption process allows for a simple system without the need for heat management using moderate pressure as a toggle. A storage material with these properties will allow the DOE system targets for storage and delivery to be achieved, providing a practical alternative to incumbents such as 700 bar systems, which generally provide volumetric storage values of 40 kgH2 m−3 or less, while retaining advantages over batteries such as fill time and energy density. Reasonable estimates for production costs and loss of performance due to system implementation project total energy storage costs roughly 5 times cheaper than those for 700 bar tanks, potentially opening doors for increased adoption of hydrogen as an energy vector.
This paper investigates the possibilities in the area of application of mobile technologies for language learning. The primary goal is to design a mobile system for learning of the Japanese language with a clear separation of content and presentation, and to leverage the learners’ interest in the Japanese language. Both the technical and the language learning perspectives are discussed. A reusable, lightweight model of learning objects with compact content and a reduced metadata set is presented. These objects are stored in a simple learning object repository that can deliver them to any client over the Internet. A mobile application is designed to use the learning object repository as its content provider, while defining its own method of presentation suitable for smaller screens of mobile devices. For the purpose of evaluation, an experiment was conducted within the e-learning system at the Faculty of Organizational Sciences, University of Belgrade. Research findings have indicated that the developed mobile application has a positive effect on the students’ interest in the subject matter.