batterydata/paper-abstracts huggingface dataset:
Due to the shorter path length and more channels for lithium ion diffusion and insertion, the two-dimensional (2D) Si nanosheets exhibit superior electrochemical performances in the field of electrochemical energy storage and conversion. Recently, various efforts have been focused on how to synthesize 2D Si nanosheets. However, there are many difficulties to achieve the larger area, high purity of 2D Si nanosheets. Herein, we developed a facile and scalable synthesis strategy to fabricate 2D Si nanosheets, utilizing the unique combination of the water-soluble NaCl particles as the sacrificial template and the hydrolyzed tetraethyl orthosilicate as the silica source, and assisting with the magnesium reduction method. Importantly, the obtained Si nanosheets have a larger area up to 10 μm2. Through combining with reduced graphene oxides (rGO), the Si nanosheets@rGO composite electrode exhibits excellent electrochemical performances. It delivers high reversible capacity about 2500 mAh g−1 at the current density of 0.2 A g−1, as well as an excellent rate capability over 900 mAh g−1 at 2 A g−1 even after 200 cycles.
Background The Continuous Performance Test (CPT) has emerged as the most commonly administered measure of sustained attention, but use of discrepant versions reduces the ability of researchers and clinicians to accurately draw cross-study conclusions. In an effort to standardize use of the CPT, this study compared four versions of the Identical Pairs CPT for their reliability and ability to discriminate between patients with schizophrenia and healthy volunteers. The relationship of performance on the different versions of the CPT with measures of psychopathology, functioning, and other aspects of cognition was also examined. Methods Performance on the 2-digit, 3-digit, 4-digit, and Shapes Identical Pairs CPT was assessed at three test sessions over five weeks, during which subjects also completed the Brief Assessment of Cognition in Schizophrenia (BACS) and questionnaires assessing psychopathology and functioning. Results All four CPTs discriminated between patients with schizophrenia and healthy volunteers, but there were no statistical differences in sensitivity among the versions. The 3-digit CPT showed non-statistical advantages in that it had high test–retest reliability, low potential for a ceiling effect, and a very low rate of false alarms. There were also moderate correlations between CPT performance and performance of the BACS subtests, but no significant correlations between CPT performance and measures of psychopathology and functioning. Conclusions While all versions of the CPT tested here had good psychometric characteristics, the 3-digit CPT-IP has some advantages in repeated measures studies such as clinical trials.
This paper reports on a relationship between the conductivity and crystallization parameters (time and temperature) of a lithium aluminum germanium phosphate (LAGP) glass–ceramic. To study the relationship, a specific formulation of the LAGP [Li1+x Al x Ge2−x (PO4)3 (x =0.5)] glass was chosen. The glass was crystallized at different temperatures and times and it was characterized for microstructures and ionic conductivity. The highest total conductivity of the glass–ceramic material, 4.22×10−3 Scm−1 at 27°C, was obtained by crystallizing the glass at 825°C for 8h. The superionic conductivity in the specimens is attributed to the space charge-mediated effect resulting from the presence of the dielectric phase (AlPO4). The impurity phase AlPO4 imparted a characteristic non-linearity in the Arrhenius plots. A decrease in conductivity with an increase in crystallization temperature and time was observed. The observed conductivity was explained on the basis of the blocking effect resulting from an increased concentration or size of the impurity phase, AlPO4. The thermally unstable nature of the LAGP is reflected by the relationship between the conductivity and the crystallization parameters. Conductivity of the glass–ceramic is believed to be significantly affected by the space charge and blocking effects that originate from and relate to the crystallization temperature and time.
Lithium-rich manganese(IV) oxide Li2MnO3 has hardly any activity as the cathode active substance of lithium-ion batteries (LIBs) but its reversible capacity can be greatly improved by introducing oxygen deficiencies. After the solid-state heat treatment of nanocrystalline Li2MnO3 by sodium borohydride (NaBH4), the resulting Li2MnO3-δ crystallites comparatively acquire distinguishable appearances in color and shape and slight differences in surface composition and lattice structure. As a LIB cathode within the potential range of 2.5–4.7 V, at 20 mA g−1 pristine Li2MnO3 gives the specific discharge capacities of 3.3, 5.0 and 7.4 mAh·g−1 in the 1st, 10th and 100th cycles, while the derivative Li2MnO3-δ delivers the relatively high values of 64.8, 103.8 and 140.2 mAh·g−1 in the 1st, 10th and 120th cycles, respectively. Aside from the similar phenomenon of gradual electrochemical activation, substituting Li2MnO3-δ for Li2MnO3 means the great enhancements of charge-transfer ability and electrochemical performances. Especially, the cationic-anionic redox mechanisms of Li2MnO3 and Li2MnO3-δ are similar to each other, suggesting a possible solution to prepare high-performance xLi2MnO3-δ·(1-x)LiMO2 solid solutions for application purposes.
Nanostructured porous MnO2, especially its hydrated amorphous and low crystalline form (MnO2·nH2O), has been one of the most promising material considered for charge storage applications, due to electrochemical similarities with RuO2 and its relative low cost. However, the intrinsic poor conductivity of MnO2 combined with the presence of structural water, which provides high ionic but low electronic conductivity, is a great hindrance for wider application. An effective approach to overcome this drawback involves the deposition of thin MnO2 layers on porous, high surface area metallic scaffolds. The present work addresses this route and provides novel insights thanks to the combination of MnOx·nH2O with custom-made Ni foams, fabricated via one-step electrodeposition using the dynamic hydrogen bubble template (DHBT). The porous Ni foams provide a scaffold with a 3D architecture with optimized pore size and surface. The composite electrode was fabricated by anodic deposition of MnOx·nH2O on the 3D Ni foams. The electrochemical behaviour was tested in 1 M KOH, since there are very few studies addressing the electrochemical behaviour of MnOx·nH2O in alkaline media for electrochemical supercapacitors applications. In addition, thermal treatment (150–250 °C) was performed to evaluate the effect of hydration on the material properties. The results revealed that the as-obtained composites are highly stable, displaying much higher specific capacitances with 73–90% (depending on the mass load) capacitance retention compared to their de-hydrated counterparts. The charge-discharge processes were found to be highly reversible throughout 5000 cycles, maintaining almost 100% columbic efficiency. In conclusion, the MnOx·nH2O@Ni composite electrodes showed a very stable pseudocapacitive behaviour and exceptional cycling performance in 1 M KOH, being therefore a promising alternative charge storage electrode for electrochemical supercapacitors.
Metallic lithium is one of the most promising anode materials for rechargeable lithium-based batteries owing to its high theoretical capacity of 3860mAhg−1. However, several severe issues such as uncontrollable lithium dendrites and infinitely large volume change are urgently needed to be solved, since they cause very short cycle life and severe safety hazards. Here we explore an effective strategy to create lamellar structured flexible Ti3C2 MXene (graphene, BN)-lithium film anode, based on the unique ductility of metallic lithium and lubricity of these nanosheets. By harnessing the lithiophobic property of atomic layers, not only the nucleation and growth of lithium dendrites can be efficiently controlled, but also the plating lithium is well confined in the nanoscaled gaps of above nanosheets. As a consequence, the optimal Ti3C2 MXene-lithium film anode exhibits significantly low overpotential (32mV at 1.0mAcm–2) with a very small increase of 1.5% in 200 cycles, flat voltage profiles and good high-rate performances (53mV at 3.0mAcm–2).
Objective Ziprasidone may improve cognition in schizophrenia; however, this could be related to clinical symptom improvement, reflecting “pseudospecificity”. We tested the hypothesis that ziprasidone improves cognition in the absence of clinical improvement. Methods We conducted a 12-week, open-label study of ziprasidone in 10 schizophrenia patients who met non-response criteria (<20% reduction in BPRS scores over 12 weeks). We conducted comprehensive cognitive testing and assessed change from baseline to end of study. Results We detected significant improvement on three measures of episodic memory (p <0.01) in these clinically non-responsive patients. Trend-level improvements were noted on tests involving processing speed and executive function. Conclusions These data suggest that ziprasidone has cognitive benefits unrelated to an influence on other disease parameters.
The reactivity of 1,8-octanedithiol/Au(111) self-assembled monolayers (SAMs) formed by the immersion method was investigated by means of cyclic voltammetry (CV), scanning tunneling microscopy (STM), electrochemical impedance spectroscopy (EIS) and quantum mechanical calculations. The potential of the reductive desorption process for the dithiol is 99mV more negative than for 1-octanethiol indicating a higher stability of dithiol monolayers. A reduction charge of −109μC/cm2 was obtained for the dithiol which is to be compared to the reductive desorption charge of −83μC/cm2 for the monothiol. The extra reduction charge of the dithiol was attributed to the presence of intralayer disulfide bonds at the SAM/electrolyte interface. EIS measurements confirmed that these intralayer linkages increase the stability of the monolayer with respect to the homologue 1-octanethiol/Au(111). The onset of the reductive desorption of the dithiol is characterized by the appearance of a striped structure which is attributed to flat lying molecules. In alkaline electrolyte, the complete reduction of the dithiol monolayer occurs at the most negative potentials at which the herringbone reconstruction of the gold substrate is clearly imaged together with gold islands. Density functional calculations confirmed that intralayer disulfide bond formation is energetically favorable when the adjacent alkyl chains are arranged in an antiparallel configuration. We observed that the concentration of surface disulfides for 1,8-octanedithiol monolayers is lower than for 1,6-hexaneditiol monolayers. A model was proposed to explain the effect of chain length on the reactivity of α,ω-alkanedithiols.
Carbon monoxide (CO) and particulate matter (PM2.5) were measured in two reconstructed Danish farmhouses (17–19th century) during two weeks of summer. During the first week intensive measurements were performed while test cooking fires were burned, during the second week the houses were monitored while occupied by guest families. A masonry hearth was located in the middle of each house for open cooking fires and with heating stoves. One house had a chimney leading to the outside over the hearth; in the other, a brickwork hood led the smoke into an attic and through holes in the roof. During the first week the concentration of PM2.5 averaged daily between 138 and 1650 μg m−3 inside the hearths and 21–160 μg m−3 in adjacent living rooms. CO averaged daily between 0.21 and 1.9 ppm in living areas, and up to 12 ppm in the hearths. Highest concentrations were measured when two fires were lit at the same time, which would cause high personal exposure for someone working in the kitchens. 15 min averages of up to 25 400 μg m−3 (PM2.5) and 260 ppm CO were recorded. WHO air quality guidelines were occasionally exceeded for CO and constantly for PM2.5. However, air exchange and air distribution measurements revealed a large draw in the chimney, which ensured a fast removal of wood smoke from the hearth area. The guest families were in average exposed to no more than 0.21 ppm CO during 48 h. Based on a hypothetical time-activity pattern, however, a woman living in this type of house during the 17–19th century would be exposed to daily averages of 1.1 ppm CO and 196 μg m−3 PM2.5, which exceeds WHO guideline for PM2.5, and is comparable to what is today observed for women in rural areas of developing countries.
This study examined the impact of various degenerative dementias on access to semantic knowledge and the status of semantic representations. Patients with semantic dementia, primary progressive aphasia, and Alzheimer’s disease were compared with elderly controls on tasks of category and letter fluency, with number of words generated, mean lexical frequency and errors recorded. The findings are consistent with the view that category and letter fluency rely on both common and unique cognitive processes. Fluency tasks, with the richness of data obtained, are valuable in distinguishing different dementia syndromes from one another.
Carbon-coated LiMn x Fe1−x PO4 (x = 0, 0.5 and 1) is fully delithiated using NO2BF4 oxidant to investigate thermal behavior as a function of temperature as high as 700 °C in an Ar atmosphere. Reitveld refinement of X-ray diffraction (XRD) studies indicates readiness of chemical delithiation, except for Li0MnPO4, hydrated to amorphous MnPO4·2H2O. Thermal studies coupled with thermogravimetric analysis and in situ high temperature XRD demonstrate that the phase stability is affected by substituted Mn at an elevated temperature. The Li0FePO4 is stable up to 500 °C, maintaining the original olivine structure with a small amount of oxygen release. At higher temperatures, the phase was transformed to Fe3(PO4)2 and Fe2P2O7. In contrast, the phase transformation temperature is apparently reduced to as low as 200 °C by the addition of Mn into the crystal structure, which is related to the phase transformation to (Mn0.5Fe0.5)3(PO4)2 associated with fast oxygen loss from the original structure. As a result, the better thermal stability of Li0FePO4 is attributed to less oxygen loss, which delays the phase transformation, resulting in less exothermic heat in the temperature range.
Cognitive impairment negatively affects some cancer survivors who have completed chemotherapy; however, factors underlying this cognitive impairment remain poorly understood. We aimed to investigate (1) the relative importance of demographics, medical, and psychological characteristics associated with cognitive impairment and (2) the specific variables associated with cognitive impairment in adult cancer survivors who completed adjuvant chemotherapy.
Hydrocalumites additives are synthesized and proposed as an anodic additive for Zinc/Nickel alkaline secondary batteries. The as-prepared additives are characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). And the results illustrate that hydrocalumites additives are successfully prepared and have the typical structure of layered double hydroxides (LDHs). The effects of hydrocalumites additives on electrochemical performances of ZnO have been investigated by cyclic voltammetry (CV), tafel polarization tests, electrochemical impedance spectroscopy (EIS) and galvanostatic charge and discharge. Compared to the electrode with pure ZnO, the electrodes containing hydrocalumites additives show better reversibility, reveal better anti-corrosion property and exhibit more stable cycle performance. Especially when the electrode added with 12% (wt.) hydrocalumites, it exhibits the best cycle performance than the other electrodes. And its discharge capacity is about 450mAhg−1 all the time, and hardly declines over all the 400 cycles. Based on these observations, the prepared hydrocalumites may be a promising and efficient additive for the ZnO electrode.
Novel acid-base blend membranes composed of sulfonated poly (ether ether ketone) (SPEEK) and polyetherimide (PEI) were prepared for vanadium redox flow battery (VRB). The blend membranes were characterized by Fourier transform infrared spectroscopy (FT-IR) and scanning electronic microscopy (SEM). The ion exchange capacity (IEC), proton conductivity, water uptake, vanadium ion permeability and mechanical properties were measured. As a result, the acid-base blend membranes exhibit higher water uptake, IEC and lower vanadium ion permeability compared to Nafion117 membranes and all these properties decrease with the increase of PEI. In VRB single cell test, the VRB with blend membranes shows lower charge capacity loss, higher coulombic efficiency (CE) and energy efficiency (EE) than Nafion117 membrane. Furthermore, the acid-base blend membranes present stable performance up to 50 cycles with no significant decline in CE and EE. All experimental results indicate that the SPEEK/PEI (S/P) acid-base blend membranes show promising prospects for VRB.
Combined heat and power on a residential scale, also known as micro-cogeneration, is currently gaining traction as an energy savings practice. The configuration of micro-cogeneration systems is highly variable, as local climate, energy supply, energy market and the feasibility of including renewable type components such as wind turbines or photovoltaic panels are all factors. Large-scale lithium ion batteries for electrical storage in this context can provide cost savings, operational flexibility, and reduced stress on the distribution grid as well as a degree of contingency for installations relying upon unsteady renewables. Concurrently, significant advances in component materials used to make lithium ion cells offer performance improvements in terms of power output, energy capacity, robustness and longevity, thereby enhancing their prospective utility in residential micro-cogeneration installations. The present study evaluates annual residential energy use for a typical Canadian home connected to the electrical grid, equipped with a micro-cogeneration system consisting of a Stirling engine for supplying heat and power, coupled with a nominal 2kW/6kWh lithium ion battery. Two novel battery cathode chemistries, one a new Li–NCA material, the other a high voltage Ni-doped lithium manganate, are compared in the residential micro-cogeneration context with a system equipped with the presently conventional LiMn2O4 spinel-type battery.
We have designed an aqueous gel electrolyte containing fumed silica as the thixotropic gelling agent and poly(ethylene glycol) (MW=300g·mol−1) as the non-thixotropic gelling agent. Poly(ethylene glycol) is also the dendrite suppressor and the corrosion inhibitor. Both PEG300 and fumed silica can inhibit dendrite formation, shown by chronoamperometry results and ex-situ scanning electron microscopy images. Furthermore, the corrosion current density on the Zn anode in the 4wt%FS-1wt%PEG300 gel electrolyte is 27% less than that of the Zn in the reference aqueous electrolyte. Secondary Zn/LiMn2O4 batteries using the 4wt%FS-1wt%PEG300 gel electrolyte exhibit higher cyclability (12% and 39% higher capacity retention, after 300 and 1000cycles, in Swagelok and large cells, respectively) than those using the reference aqueous electrolyte. The vast improvements in cycling performance, reliability, and higher resistance to premature failure makes the PEG-FS gel a much better alternative to liquid electrolytes for maintenance-free energy storage applications.
In this study, we introduce a novel all-polymer battery system based on conducting polymer (polypyrrole, PPy) doped with dopants of para (toluene sulfonic acid) (pTS) and indigo carmine (IC), respectively. The performance of the systems consisting of polypyrrole–para (toluene sulfonic acid) (PPy–pTS) as cathode and polypyrrole–indigo carmine (PPy–IC) as anode in conjunction with either a polymer based electrolyte or a commercial organic electrolyte of 1M LiPF6 in a 50:50 (v/v) mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) was evaluated. In the system, all the free-standing PPy–pTS and PPy–IC films were directly used without needing any metal substrate support to hold the electro active material. Electrochemical measurements demonstrated that the PPy–pTS/PPy–IC (commercial electrolyte) system exhibited a reversible discharge capacity of 36mAhg−1 at 0.05mAcm−2 after 50 cycles, is 92% of the initial discharge capacity. In the case of PPy–pTS/PPy–IC (polymer electrolyte), the reversible discharge capacity after 50 cycles was 16mAhg−1, 76% of the intial discharge capacity. This work deals with the fabrication of a novel all polymer battery system, with significant advantages in terms of capacity and reasonable stability. This may lead to a future generation of all polymer batteries that are suitable for implanted medical devices used in biological and biomedical systems.
Among the contenders in the new generation energy storage arena, all-solid-state batteries (ASSBs) have emerged as particularly promising, owing to their potential to exhibit high safety, high energy density and long cycle life. The relatively low conductivity of most solid electrolytes and the often sluggish charge transfer kinetics at the interface between solid electrolyte and electrode layers are considered to be amongst the major challenges facing ASSBs. This review presents an overview of the state of the art in solid lithium and sodium ion conductors, with an emphasis on inorganic materials. The correlations between the composition, structure and conductivity of these solid electrolytes are illustrated and strategies to boost ion conductivity are proposed. In particular, the high grain boundary resistance of solid oxide electrolytes is identified as a challenge. Critical issues of solid electrolytes beyond ion conductivity are also discussed with respect to their potential problems for practical applications. The chemical and electrochemical stabilities of solid electrolytes are discussed, as are chemo-mechanical effects which have been overlooked to some extent. Furthermore, strategies to improve the practical performance of ASSBs, including optimizing the interface between solid electrolytes and electrode materials to improve stability and lower charge transfer resistance are also suggested.
Lithium–sulfur (Li–S) batteries have high theoretical specific capacity, providing new opportunities for the next generation of secondary battery. Covalent organic framework (COF) as a new porous crystalline material has been used as the host material in Li–S battery to improve the cell's cycling stability. In this paper, an imine-linked TAPB-PDA-COF was applied as the host material for sulfur loading (60%) in Li–S battery. The TAPB-PDA-COF has a beehive-like morphology with high thermal stability (up to 500 °C). In the electrochemical experiment, the performance of the composite cathode with acetylene black (A-B) and super-P (S-P) as the conductive additives was studied individually. The initial discharge capacity under 0.2 A/g current density was 991 mAh/g and 1357 mAh/g for TAPB-PDA-COF/S@A-B and TAPB-PDA-COF/S@S-P, respectively. The better result of S-P based cathode than A-B could be due to the better conductivity of the S-P, as proved by the EIS results. When further increased the current density to 2 A/g, the S-P based composite cathode can still deliver a comparable initial discharge capacity of 630 and 274 mAh/g capacity remained after 940 cycles. This results will inspire researchers develop more suitable conductive additives together with the host materials for high performance Li–S battery.