batterydata/paper-abstracts huggingface dataset:
Highly porous nickel cobaltite (NiCo2O4) materials have been synthesized via a facile and scalable chemical synthesis route. The obtained NiCo2O4 material displays a typical secondary submicron/micron-sized (0.1–2μm) agglomerate morphology, exhibiting large surface area (190.1m2 g−1) and high porosity (1.136cm3 g−1). The fabricated NiCo2O4 electrode shows high specific capacitance (351Fg−1 at 1Ag−1) and high-rate capability (82.1% capacitance retention at 8Ag−1), which is superior to many reported NiCo2O4 materials. Further, the assembled AC-NiCo2O4 aqueous hybrid capacitor exhibits high power and energy densities (2805Wkg−1, 6.8Whkg−1 at 8Ag−1) and high cycling stability (15% loss after 5000 cycles at 1.5Ag−1). The high-performance of the NiCo2O4 materials is attributed to their large surface area and highly porous structure which contribute to rich surface electroactive sites and easy ions transport pathways for facile electrochemical reactions.
Transition metal carbides (TMCs), known to deliver extra capacity beyond the theoretical limit, are proposed as emerging high-capacity anodes for next-generation lithium ion batteries (LIBs). Nevertheless, the underlying mechanism for the extra lithium storage in TMCs has not been revealed clearly due to the electrochemical inertness of TMCs to Li in cycling. Here, for the first time, by employing in situ Raman and X-ray photoelectron spectroscopies, we corroborate that the capacity enhancement of Fe3C anodes originates from the physiochemical evolution of solid electrolyte interphase (SEI) and surface carbonaceous materials through three mechanisms: (i) Fe3C catalyzes the reversible conversion between esters and ethers to store extra lithium ions in the SEI; (ii) Fe and inorganic components embedded in the SEI form a reversible surface-conversion reaction of Fe + 3LiF ⇌ FeF3 + 3Li+ + 3e− to contribute additional capacity; and (iii) surficial carbon delivers capacity through surface capacitive effects and Li+ inter/deintercalation processes. With the extra lithium ion storage in the SEI and carbon, the C@Fe3C/Fe anode delivers a high reversible capacity of 808 mA h g−1 after 700 cycles at 1 A g−1. This study provides a fundamental basis for emerging high-capacity TMC anodes to be efficiently explored for next-generation LIBs.
Experiments were conducted to study the dynamics of nitrous oxide (N2O) emission from wheat varieties viz., Sonalika, HUW 468, HUW 234 and DBW 14 grown in alluvial soils of North Bank Plain Agroclimatic Zone of Assam, India. Attempts were made to find out the relationship of N2O emission with plant morphophysiological, anatomical and soil properties. N2O fluxes from wheat varieties ranged from 40 μg N2O–N m−2 h−1 to 295 μg N2O–N m−2 h−1. Soil organic carbon and soil temperature have shown significant relationship with N2O flux. The rate of leaf transpiration recorded from the wheat varieties at different growth stages exhibited a positive correlation with N2O emission suggesting that movement of N2O along with the transpirational water flow may be an important mechanism of N2O transport and emission through wheat plants. Anatomical investigation by scanning electron microscope revealed that N2O emission has relationship with stomatal frequency of leaf and leaf sheaths. Variety HUW 234 with the highest stomatal frequency of leaf and leaf sheath also recorded higher seasonal N2O emission compared to other varieties. Seasonal N2O emission (Esif) of the varieties ranged from 3.25 to 3.81 kg N2O–N ha−1. Significant variations in Esif values were recorded within the varieties.
Sulfolane (also referred to as tetramethylene sulfone, TMS) containing LiPF6 and vinylene carbonate (VC) was tested as a non-flammable electrolyte for a graphite |LiFePO4 lithium-ion battery. Charging/discharging capacity of the LiFePO4 electrode was ca. 150mAhg−1 (VC content 5wt%). The capacity of the graphite electrode after 10 cycles establishes at the level of ca. 350mAhg−1 (C/10 rate). In the case of the full graphite |1M LiPF6 +TMS+VC 10wt% |LiFePO4 cell, both charging and discharging capacity (referred to cathode mass) stabilized at a value of ca. 120mAhg−1. Exchange current density for Li+ reduction on metallic lithium, estimated from electrochemical impedance spectroscopy (EIS) experiments, was j o(Li/Li+)=8.15×10−4 Acm−2. Moreover, EIS suggests formation of the solid electrolyte interface (SEI) on lithium, lithiated graphite and LiFePO4 electrodes, protecting them from further corrosion in contact with the liquid electrolyte. Scanning electron microscopy (SEM) images of pristine electrodes and those taken after electrochemical cycling showed changes which may be interpreted as a result of SEI formation. No graphite exfoliation was observed. The main decomposition peak of the LiPF6 +TMS+VC electrolyte (TG/DTA experiment) was present at ca. 275°C. The LiFePO4(solid)+1M LiPF6 +TMS+10wt% VC system shows a flash point of ca. 150°C. This was much higher in comparison to that characteristic of a classical LiFePO4 (solid)+1M LiPF6 +50wt% EC+50wt% DMC system (T f ≈37°C).
Li-ion batteries (LIBs) are favoured in many applications due to their high energy density and good cyclic performance. However, some safety concerns remain with respect to the risk of fires and explosions with LIBs. Carbon-based anode materials in LIBs operate close to the Li metal reduction potential, therefore Li dendrites can grow during voltage fluctuations, causing short circuits which may lead to fires. The Cu6Sn5 anodes has the lithiation potential at about 0.4 V vs Li/Li+ and therefore less prone to Li metal plating. A new manufacturing method involving direct in-situ formation of Cu6Sn5 on a Cu current collector via melt-solid contact is proposed. This method combines the active material production and the anode fabrication into a single process. Lithiation and delithiation mechanisms of the anode produced are studied by in-situ synchrotron X-ray powder diffraction (XRPD) and ex-situ high voltage transmission electron microscope (HV-TEM). The in-situ XRPD study shows a reversible two-step reaction during cycling, and also reveals the differences in the reaction mechanisms at higher charge/discharge rates than those in published data.
A multi-geometry and multi-physics model is developed for a Li-ion battery module which includes three cells connected in series by electrical busbars. The model can be used to predict the 3D profiles of the electrical potentials and temperature in the battery. The physics-based porous electrode (P2D) model is used to predict the electrochemical behavior of the cells, and the coupling between the P2D model and the electrical/thermal equations is simplified through a linear approximation method. This approximation is useful at rates of at least 5C and reduces the computation time significantly. The anisotropic conductive properties for the regions where conductors are separately arrayed are discussed in detail, and the model predictions are presented and discussed.
This paper presents a new algorithm for managing solar PV intermittency in green buildings using demand response management (DRM) technique. The proposed DRM algorithm utilizes the building air conditioning and mechanical ventilation (ACMV) system to dynamically compensate for the deficit of power generated by solar PV system from its rated capacity. For example, the developed solution will reduce the load demand of the ACMV system equal to the drop of solar generation by controlling the speed of the fan. This will ensure that the amount of power supplied by the grid to the building will remain the same (as before the drop of solar generation) and thus no impact on the grid stability. However, since ACMV system is directly linked to building occupant comfort/health, the proposed solution will also include energy storage management and priority-based load shedding programs to provide support when room temperature (air conditioning) or CO level (ventilation) is above regulatory limit. A thermal model for building temperature variation is developed to test and analyze the proposed algorithm to dynamically manage solar PV fluctuation.
While carbon fiber paper (CFP) has been widely used in batteries, fuel cells, and supercapacitors, its effect on device performance can be rather complicated. In this study, we examined the effect of CFP from different batches on the performance of a CFP-supported MnOx hybrid supercapacitor (CFP/MnOx). It is found that the contribution of the MnOx to the capacitance is dominating if the MnOx coating on CFP is dense and conformal, but becomes much less significant if the MnOx coating on CFP is porous or non-conformal. This is because annealing CFP/MnOx at 400 °C in air is necessary to obtain proper MnOx phases for high capacitance; the annealing process may increase the specific surface area of CFP if it is not fully covered by MnOx. Also, the etching of carbon surface weakens the attachment of MnOx to CFP and worsens the electrical connection of MnOx to CFP, further reducing the contribution of MnOx to capacitance. Finally, much to our surprise, it is found that the properties of the CFP varied from batches to batches, which critically influence the MnOx coating morphology/density. These factors in turn greatly affect the contribution of each component to the capacitance of the CFP/MnOx hybrid supercapacitors.
This preliminary randomized controlled trial compared Training Executive, Attention and Motor Skills (TEAMS), a played-based intervention for preschool children with attention-deficit/hyperactivity disorder (ADHD), to an active comparison intervention consisting of parent education and support (ClinicalTrials.gov Identifier: NCT01462032). The primary aims were to gauge preliminary efficacy and assist in further development of TEAMS. Four- and 5-year-old children with ADHD were randomly assigned to receive TEAMS (N = 26) or the comparison intervention (N = 26) with blinded assessments by parents, teachers and clinicians ascertained pretreatment, post-treatment, and 1- and 3-months post-treatment. Changes in ADHD severity, impairment, parenting factors, and neuropsychological functioning over time as a function of treatment condition were assessed using the PROC MIXED procedure in SAS. Across most measures, significant main effects for Time emerged; both treatments were associated with reduced ADHD symptoms that persisted for three months post-treatment. There were no significant Treatment effects or Time x Treatment interactions on symptom and impairment measures, suggesting that the magnitude of improvement did not differ between the two interventions. However, significant correlations emerged between the magnitude of behavioral change, as assessed by parents and clinicians, and the amount of time families engaged in TEAMS-related activities during treatment. Across a wide array of parenting and neuropsychological measures, there were few significant group differences over time. TEAMS and other psychosocial interventions appear to provide similar levels of benefit. Play-based interventions like TEAMS represent a potentially viable alternative/addition to current ADHD treatments, particularly for young children, but more research and further development of techniques are necessary.
The formation and evolution of the solid electrolyte interface (SEI) film during the first electrochemical intercalation of lithium into graphite were modeled as a special precipitation process including a nucleation phase of the SEI film's solid deposition, and followed by a growth phase involving the precipitation of new solids on previously formed solid nuclei. It was shown that the solid species can nucleate in the electrolyte solution, directly on the graphite surface, or adjacent to an already present particle on the graphite surface when precipitating from the electrolyte solution. Within the framework of classical nucleation theory (CNT), we can qualitatively explain the origin of the two-layer structure of SEI films, which consists of a thin, compact polycrystalline or heteromicrophase layer rich in inorganic species (e.g., LiF, Li2O) close to the electrode, and a thicker porous and amorphous layer composed mainly of organic compounds (e.g., ROLi, ROCO2Li) that is farther from the graphite.
Tailored 3D Ni foams with smaller macropores and larger surface areas than commercial Ni foams are prepared by electrodeposition under the dynamic hydrogen bubble template on stainless steel substrates. These Ni foams are functionalized with electrodeposited manganese oxide (MnOx), resulting in MnOx/Ni foam composites. The electrochemical performance of the composites is studied in aqueous Na2SO4 and KOH electrolyte. Moreover, asymmetric cells, combining the MnOx/Ni foam composites as positive electrodes and carbon cloths as negative electrodes, are tested in the presence of the two electrolytes. Despite the significant number of papers dealing with asymmetric supercapacitors, there is still the need of understanding the electrolyte role for optimizing their electrochemical response. The cell potential window is broader in neutral electrolyte, 1.6 V, compared to the alkaline one, 1.2 V, but the cell capacitance is lower in the neutral electrolyte, 37 F g−1, than in the alkaline one, 49 F g−1. The energy density is similar for the two electrolytes, ca. 10 Wh kg−1. The power density reaches 1-3∙104 W kg−1, which is among the highest values reported for asymmetric cells in aqueous electrolytes. The stability of the cells on cycling, floating and self-discharge are compared for the two electrolytes.
Nanomaterials have been widely used in diverse areas. Heavy metals are ubiquitous environmental pollutants. In spite of the real risk of humans’ co-exposure to nanoparticles and heavy metals, their combined toxicity has received little attention. We have reported that silica nanoparticles and CdCl2 have a positive synergistic toxicity in mice. Here, we demonstrate that Fe3O4 nanoparticles (nano-Fe3O4) and CdCl2 have a negative synergistic toxicity in mice. Nano-Fe3O4 showed low toxicity in mice. In contrast, CdCl2 caused significant oxidative damage mainly in the liver as indicated by severe liver dysfunction and histopathological abnormalities. Co-exposure to nano-Fe3O4 and CdCl2 significantly attenuated CdCl2-induced damage in the liver through reduction of oxidative stress. Nano-Fe3O4 and CdCl2 had negative cooperative effects on the biodistributions of Fe and Cd in mice due to mutually competitive inhibition of Fe and Cd uptake. The reduction of Cd accumulation in tissues and the inhibition of Cd-induced deprivation of tissue Fe by nano-Fe3O4 played two key roles in the protective effect of nano-Fe3O4 on CdCl2-induced oxidative damage.
AgFeO2 nanoparticles synthesized via precipitation at room temperature are investigated in Li- and Na-ion cells through electrode coatings with an alginate binder. The electrochemical reactions of AgFeO2 with Li+ and Na+ ions, as well as its role as alternative negative electrode in these cell systems are carefully evaluated. Initial Li uptake causes irreversible amorphization of the AgFeO2 structure with concomitant formation of Ag0 nanoparticles. Further Li incorporation results in conversion into Fe0 nanoparticles and Li2O, together with Li-alloying of these Ag0 clusters. Similar mechanisms are also found upon Na uptake, although such processes are hindered by overpotentials, the capacity and reversibility of the reactions with Na+ ions being not comparable with those of their Li+ counterparts. The behaviour of AgFeO2 at low potentials vs. Li+/Li displays a synergic pseudo-capacitive charge storage overlapping Li-Ag alloying/de-alloying. This feature is exploited in full cells having deeply lithiated AgFeO2 and LiFePO4 as negative and positive electrodes, respectively. These environmentally friendly iron-based full cells exhibit attractive cycle performances with ≈80% capacity retention after 1000 cycles without any electrolyte additive, average round trip efficiency of ≈89% and operational voltage of 3.0 V combined with built-in pseudo-capacitive characteristics that enable high cycling rates up to ≈25C.
Here, we report preparation of nitrogen-modified nanostructure carbons through carbonization of Cu-based metal organic nanofibers at 700°C under argon gas atmosphere. After removal of copper through chemical treatment with acids, pure N-modified nanostructure carbon with a nitrogen content of 8.62 wt% is obtained. When use as anodes for lithium-ion battery, the nanostructure carbon electrode has a discharge capacity of 853.1 mAh g−1 measured at a current of 500mA g−1 after 800 cycles.
The latest researches have adopted software technology, turning the Nintendo Wii Balance Board into a high performance standing location detector with a newly developed standing location detection program (SLDP). This study extended SLDP functionality to assess whether two people with developmental disabilities would be able to actively perform simple occupational activities by controlling their favorite environmental stimulation using Nintendo Wii Balance Boards and SLDP software. An ABAB design was adopted in this study to perform the tests. The test results showed that, during the intervention phases, both participants significantly increased their target response (i.e. simple occupational activity) to activate the control system to produce environmental stimulation. The practical and developmental implications of the findings are discussed.
Lithium-rich and Ni-rich cathode materials have been considered as the attractive candidate for their high capacitive performance, but usually exhibit poor rate performance and limited cycle life. Herein, a facile gaseous sulfur treatment was developed to uniformly create oxygen vacancies and replace oxygen with sulfur atoms at the surface region of lithium-rich and Ni-rich cathode materials. Such a treatment, when applied to typical Li- or Ni- rich materials such as Li1.2Ni0.13Co0.13Mn0.54O2 (LNCMO), Li1.2Ni0.2Mn0.6O2 (LNMO) and LiNi0.8Co0.1Mn0.1O2 (NCM811), could enhance significantly all their cycle and rate performance. For example, LNCMO@S obtained from LNCMO, could exhibit a capacity retention of 81.10% after 600 cycles at 0.5 C (compared with 65.78% of LNCMO after 200 cycles), together with an excellent rate performance of 174.8 mA h g−1 at 10 C (compared with 133.3 mA h g−1 of LNCMO), which is among the best performance for all Li-rich cathode materials. The revealed mechanism, where the partial replacement of O by S at the lattice surface significantly reduces oxygen partial pressure and also enhances the Li ion conductivity, might shed light on the comprehensive design and control of oxygen activity in transition-metal-oxide systems for Li-ion batteries with high energy and power density.
Background Two previous studies of SB742457, a 5-hydroxytryptamine (5-HT6) receptor antagonist, suggested the efficacy of improvements in cognition and global outcome in Alzheimer's disease (AD). Methods Two randomized, placebo-controlled trials investigated SB742457 15 and 35 mg daily in subjects with mild-to-moderate AD (Mini-Mental Health State Examination [MMSE] 10–26). Study 1 (n = 576) investigated SB742457 and donepezil (5–10 mg daily) as monotherapy for 6 months. Study 2 (n = 684) investigated SB742457 in subjects who were maintained on donepezil. Coprimary endpoints at 24 weeks assessed cognition (AD Assessment Scale-Cognitive Subscale [ADAS-Cog]) and global outcome (Study 1: Clinician Interview-Based Impression of Change Plus Caregiver Input [CIBIC+]; Study 2: Clinical Dementia Rating-Sum of Boxes [CDR-SB]). Safety was assessed throughout. Results Both studies failed to achieve formal statistical significance for their primary objectives. Study 1: SB742457 monotherapy was not statistically significantly different from placebo on any endpoint. Donepezil improved CIBIC+ but not ADAS-Cog. Study 2: SB742457 35 mg showed statistically significant differences relative to placebo for ADAS-cog (weeks 12, 24, and 48, but not week 36), ADCS-ADL (weeks 12–36, but not week 48), and CDR-SB (week 12 only). Conclusion Neither study met the overall criteria for success, but as an adjunct to donepezil, SB742457 was associated with sustained improvements for up to 48 weeks in cognition and ADL, compared with donepezil alone. Clinical Trial Registration: Clinicaltrials.gov: Study 1 NCT00708552; Study 2 NCT00710684.
Lithium polysulfide (LiPS) shuttling is one of the main obstacles hindering the practical use of lithium-sulfur (Li-S) batteries. Constructing an interlayer composed of carbon or noncarbon materials on separator is a promising way to restrain the LiPS shuttling, but such a layer always hinders the Li ion diffusion and is hard to realize the reuse of the captured LiPSs. In this study, an in-plane heterostructure constructed by graphene and titanium carbide (TiC) was prepared by directly using graphene as a template and the carbon source to react with TiCl4 under thermal treatment. In this process, graphene was partially transformed into TiC forming such a heterostructure, which is benefit to reducing the Li ion and electron diffusion barrier. Moreover, the TiC has strong affinity towards LiPSs and high conductivity. Thus, the in-plane heterostructures filtered on a separator as a coating layer effectively blocks the shuttle of LiPSs and greatly improves the sulfur utilization and cycling performance, indicating a promising way to promote the practical applications of high performance Li-S batteries.
Polyoxometalates (POMs) represent a class of nanomaterials, which hold enormous promise for a range of energy-related applications. Their promise is owing to their “special” structure that gives POMs a truly unique ability to control redox reactions in energy conversion and storage. One such amazing capability is their large number of redox active sites that arises from the complex three-dimensional cluster of metal-oxide ions linked together by oxygen atoms. Here, a critical review on how POMs emerged from being molecular clusters for fundamental studies, to next-generation materials for energy applications is provided. We highlight how exploiting the versatility and activity of these molecules can lead to improved performance in energy devices such as supercapacitors and batteries, and in energy catalyst applications. The potential of POMs across numerous fields is systematically outlined by investigating structure–property–performance relationships and the determinant factors for energy systems. Finally, the challenges and opportunities for this class of materials with respect to addressing our pressing energy-related concerns are identified.
The pathophysiology underlying freezing of gait (FOG) in Parkinson's disease remains incompletely understood. Patients with FOG (“freezers”) have a higher temporal variability and asymmetry of strides compared to patients without FOG (“non-freezers”). We aimed to extend this view, by assessing spatial variability and asymmetry of steps and interlimb coordination between the upper and lower limbs during gait. Twelve freezers, 15 non-freezers, and 15 age-matched controls were instructed to walk overground and on a treadmill. Kinematic data were recorded with a motion analysis system. Both freezers and non-freezers showed an increased spatial variability of leg movements compared to controls. In addition, both patient groups had a deficit in interlimb coordination, not only between ipsilateral arms and legs, but also between diagonally positioned limbs. The only difference between freezers and non-freezers was a decreased step length during treadmill walking. We conclude that parkinsonian gait—regardless of FOG—is irregular, not only in the legs, but also with respect to interlimb coordination between the arms and legs. FOG is reflected by abnormal treadmill walking, presumably because this provides a greater challenge to the defective supraspinal control than overground walking, hampering the ability of freezers to increase their stride length when necessary.