batterydata/paper-abstracts huggingface dataset:
In this work, VO4 3− substitution for PO4 3− in the Nasicon structured Li3Sc2(PO4)3 was used to enhance its ionic conductivity. The VO4 3− substitution resulted in a homogeneous compound Li3Sc2(PO4)3-x (VO4) x within a wide composition range of 0≤ x ≤ 1.2; further increase in x led to precipitation of the crystalline phases VPO5, V(PO3)3 and ScVO4. Electrical conductivity of the VO4 3−-substituted samples increased with the VO4 3− content, and the sample with x=1.5 exhibited the highest conductivity (8.41×10−3 Sm−1) at room temperature and the lowest activation energy (39.65kJmol−1). The obtained conductivity was two orders of magnitude higher than that of the non-substituted sample and nine times higher than those of the Zr4+ and SiO4 4−-substituted compounds. The present study demonstrates that the VO4 3− anion substitution for PO4 3− is a promising technique to improve ionic conductivity of the Nasicon compound.
RGO-coated Co2(OH)2CO3 nanosheet arrays, mixed with a few CoO nanowires, were synthesized and deposited on copper foil directly via a simple one-step hydrothermal procedure. Benefited from its unique chemical composition and spatial structure, the obtained samples exhibited high performance as anode material for Lithium ion batteries, which delivered a very high reversible capacity of 2,100mAhg−1 at 100mAg−1 after activation and even as high as 1,240mAhg−1 at a much higher charge/discharge current of 5000mAg−1. Additionally, the composite electrode exhibited a high cycling stability, 85% of the initial capacity was remained after 100 cycles test at 1,000mAhg−1. HRTEM analysis indicated that CO3 2− was involved into the energy storage process, which should be the key factor of such high capacity, while the covered layer of rGO and the synthesis route of directly deposition were suspected to play very important roles on the high stability and high power density.
To understand further the thermal abuse behavior of large format Li-ion batteries for automotive applications, the one-dimensional modeling approach formulated by Hatchard et al. [T.D. Hatchard, D.D. MacNeil, A. Basu, J.R. Dahn, J. Electrochem. Soc. 148(7) (2001) A755–A761] was reproduced. Then it was extended to three dimensions so we could consider the geometrical features, which are critical in large cells for automotive applications. The three-dimensional model captures the shapes and dimensions of cell components and the spatial distributions of materials and temperatures, and is used to simulate oven tests, and to determine how a local hot spot can propagate through the cell. In simulations of oven abuse testing of cells with cobalt oxide cathode and graphite anode with standard LiPF6 electrolyte, the three-dimensional model predicts that thermal runaway will occur sooner or later than the lumped model, depending on the size of the cell. The model results showed that smaller cells reject heat faster than larger cells; this may prevent them from going into thermal runaway under identical abuse conditions. In simulations of local hot spots inside a large cylindrical cell, the three-dimensional model predicts that the reactions initially propagate in the azimuthal and longitudinal directions to form a hollow cylinder-shaped reaction zone.
A cylindrical alkaline cell is modeled as a binary electrolyte system by assuming the direct electrochemical formation of ZnO in the anode. Justifications for replacing the dissolution–precipitation mechanism are provided. Compared to the original model, the binary electrolyte model has a more understandable model formulation, more consistent physical property data, and greater flexibility in certain instances. The binary electrolyte model predicts a longer cell life and higher operating voltage than the ternary electrolyte model for the test case discharge rate. There are no numerical difficulties associated with the zincate ion in the binary electrolyte model, because this species is not considered. The characteristics and advantages of the simplified anode behavior are discussed. An application of the binary electrolyte model is included.
Dimethyl-pyrrolidinum-based salts have been investigated by means of DSC, conductivity, NMR and Raman spectroscopy. The investigation aims to study the effect of the anion on the behaviour of the salt, in terms of plastic properties as well as rotational degrees of freedom of the cation. The materials range from the non-plastic iodide salt to the highly plastic BF4 salt, which flows under its own weight at elevated temperatures. The different rotational and translational motions of the cations, and the difference between rotator and plastic phases are discussed.
Positron acceleration in plasma wakefield faces significant challenges, as the positron beam must be pre-generated and precisely coupled into the wakefield and, most critically, suffers from defocusing issues. Here we propose a scheme that utilizes laser-driven electrons to produce, inject, and accelerate positrons in a single setup. The high-charge electron beam from wakefield acceleration creates copious electron–positron pairs via the Bethe–Heitler process, followed by enormous coherent transition radiation due to the electrons’ exiting from the metallic foil. Simulation results show that the coherent transition radiation field reaches up to tens of GV m−1, which captures and accelerates the positrons to cut-off energy of 1.5 GeV with energy peak of 500 MeV (energy spread ~ 24.3%). An external longitudinal magnetic field of 30 T is also applied to guide the electrons and positrons during the acceleration process. This proposed method offers a promising way to obtain GeV fast positron sources.
In order to optimize battery performance, different geometries have been evaluated taking into account their suitability for different applications. These different geometries include conventional, interdigitated batteries and unconventional geometries such as horseshoe, spiral, ring, antenna and gear batteries. The geometry optimization was performed by the finite element method, applying the Doyle/Fuller/Newman model. At 330C, the capacity values for conventional, ring, spiral, horseshoe, gear and interdigitated geometries are 0.58Ahm−2, 149Ahm−2, 182Ahm−2, 216Ahm−2, 289Ahm−2 and 318Ahm−2, respectively. The delivered capacity depends on geometrical parameters such as maximum distance for the ions to move to the current collector, d_max, distance between of current collectors, d_cc, as well as the thickness of separator and electrodes, allowing to tailor battery performance and geometry for specific applications.
We report a comparative investigation of the characteristics of modified TiO2 nanorods grown on conducting indium tin oxide glass (ITO) substrates by two different hydrothermal methods: the direct method by which rutile TiO2 nanorods were grown directly on plain ITO substrates and the seed-mediated one using which a thin film of anatase TiO2 seed layer was laid down by spin coating and annealing prior to the growth of TiO2 nanorods on it. Microstructural analysis of the samples using X-ray diffraction confirmed their rutile nature. The average crystallite size estimated using Scherrer’s formula was found to fall in the range of 11–17 nm in both cases. Field emission scanning electron microscopy revealed the nanorod morphologies of a dandelion arrangement in the case of directly grown ones and a proper vertical orientation in the case of the seed-mediated method. UV–Vis spectroscopy analysis of both the samples exhibited redshifts with intense absorption of visible radiation, and the seed-mediated one was found to possess an increased bandgap. The transport nature of the samples was characterized by significant increase in both dark and photocurrents. The results show that the dark and photocurrent values of the directly grown TiO2 nanorods were greater than those of the seed-mediated ones by ~seven and five folds, respectively, and therefore, it could serve as efficient photoelectrodes in dye-sensitized solar cells.
Due to increasing concerns on environmental pollution and depleting fossil fuels, fuel cell (FC) vehicle technology has received considerable attention as an alternative to the conventional vehicular systems. However, a FC system combined with an energy storage system (ESS) can display a preferable performance for vehicle propulsion. As the additional ESS can fulfill the transient power demand fluctuations, the fuel cell can be downsized to fit the average power demand without facing peak loads. Besides, braking energy can be recovered by the ESS. This study focuses on a vehicular system powered by a fuel cell and equipped with two secondary energy storage devices: battery and ultra-capacitor (UC). However, an advanced energy management strategy is quite necessary to split the power demand of a vehicle in a suitable way for the on-board power sources in order to maximize the performance while promoting the fuel economy and endurance of hybrid system components. In this study, a wavelet and fuzzy logic based energy management strategy is proposed for the developed hybrid vehicular system. Wavelet transform has great capability for analyzing signals consisting of instantaneous changes like a hybrid electric vehicle (HEV) power demand. Besides, fuzzy logic has a quite suitable structure for the control of hybrid systems. The mathematical and electrical models of the hybrid vehicular system are developed in detail and simulated using MATLAB®, Simulink® and SimPowerSystems® environments.
Every year 120–140million tonnes of bio-waste are generated in Europe, most of which is landfilled, incinerated or stabilized and used as covering material in landfill operation. None of these practices enables the recovery of essential nutrients such as phosphorus (P) and nitrogen (N), which are in great demand for agricultural production. Recovery of these nutrients is a matter of international concern considering the non-renewable nature of P sources and the energy intensive production process required for the synthesis of N fertilizers. The objective of this research is to understand the relation between the municipal solid waste management (MSWM) system, both its the physical components and governance aspects, and the recovery of nutrients in Vitoria-Gasteiz (Basque Country) as a benchmark for European medium-size cities. The analysis shows that the existing physical infrastructure and facilities for bio-waste have high potential for nutrient recovery, 49% for N and 83% for P contained in bio-waste. However, governance aspects of the MSWM system such as legislation and user inclusivity play an important role and decrease the actual nutrient recovery to 3.4% and 7.4% for N and P respectively.
Fuel cells (FCs) have potential as clean and efficient energy sources for automotive applications without sacrifice in performance or driving range. However, the complete FC system must operate as efficiently as possible over the range of driving conditions that may be encountered while maintaining a low cost. To achieve this target, a storage unit can be introduced in the FC system to reduce the size of the fuel cell that is the most expensive component. This “hybrid” concept would not only reduce the drive train total cost but it also allow the recover of the braking energy and the operation at the voltage–current point of maximum efficiency for the FC system. Pro-and-cons of the “full-power” versus the “hybrid” configuration are shown in this work. The “Hybridisation rate” or “Hybridisation degree”, a parameter expressed by the relationship between two installed powers, the generation power and the traction power, is also introduced and it is demonstrated that for each category of hybrid vehicles there is an optimal value of hybridisation degree. The storage systems considered are based on high power batteries or ultra capacitors (UCs) or a combination of them. A preliminary design of a sport utility vehicle (SUV) using a combined storage system and a FC energy source (called Triple Hybrid), is proposed. Finally, the experience of the Italian industry in this field is also reviewed.
Lithium ion batteries with lithium nickel cobalt manganese oxide (NCM) cathode were characterized by extensive cycling (>2000 cycles), discharge rate test, hybrid pulse power characterization test (HPPC), and electrochemical impedance spectroscopy (EIS). The crystal structure, morphology and particle size of cathode materials were characterized by X-ray diffraction and scanning electron microscopy (SEM). It was demonstrated that the rate performance and cycle life of battery are closely related to the cathode material composition and electrode design. With proper selection of cathode composition and electrode design, the lithium ion battery cell achieved close to 3500 cycles with 85% capacity retention at 1C current.
A majority of anion exchange membrane fuel cells (AEMFCs) reported in the literature have been unable to achieve high current or power. A recently proposed theory is that the achievable current is largely limited by poorly balanced water during cell operation. In this work, we present convincing experimental results – coupling operando electrochemical measurements and neutron imaging – supporting this theory and allowing the amount and distribution of water, and its impact on AEMFC performance, to be quantified for the first time. We also create new electrode compositions by systematically manipulating the ionomer and carbon content in the anode catalyst layer, which allowed us to alleviate the mass transport behavior limitations of H2/O2 AEMFCs and achieve a new record-setting peak power density of 1.9 W cm−2 – a step-change to existing literature. Our efforts cast a new light on the design and optimization of AEMFCs – potentially changing the way that AEMFCs are constructed and operated.
Psychosocial Interventions (PIs) have shown positive effects on clinical and functional outcomes of schizophrenia (SZ) in randomized controlled trials. However their effectiveness and accessibility remain unclear to date in “real world” schizophrenia. The objectives of the present study were (i) to assess the proportion of SZ outpatients who benefited from PIs between 2010 and 2015 in France after an Expert Center Intervention in a national multicentric non-selected community-dwelling sample; (ii) to assess PIs’ effectiveness at 1-year follow-up. 183 SZ outpatients were recruited from FondaMental Advanced Centers of Expertise for Schizophrenia cohort. Baseline and 1-year evaluations included sociodemographic data, current treatments, illness characteristics and standardized scales for clinical severity, adherence to treatment, quality of life, a large cognitive battery, and daily functioning assessment. Only 7 (3.8%) received a PI before the evaluation, and 64 (35%) have received at least one PI during the 1-year follow-up. Having had at least one PI during the follow-up has been associated in multivariate analyses with significantly higher improvement in positive and negative symptoms (respectively p =0.031; p = 0.011), mental flexibility (TMT B, p = 0.029; C-VF, p = 0.02) and global functioning (p =0.042). CBT and SST were associated with higher cognitive improvements, while CRT was associated with clinical improvement. These results have not been demonstrated before and suggest that the effect of each PI is larger than its initial target. The present study has confirmed the PIs’ effectiveness in a large sample of community-dwelling SZ outpatients at 1 year follow-up. Efforts to improve access to PI should be reinforced in public health policies.
A 3D hierarchical porous composite structure is developed via the controlled electrodeposition of a polyaniline nanofiber sponge (PANI-NFS) that fills the pores of a chemical vapor deposited graphene foam (GF). The PANI-NFS/GF composite combines the efficient electronic transport in the GF scaffold (with 100–500 μm pore size) with the rapid diffusion of the electrolyte ions into the high-specific-surface-area and densely-packed PANI-NFS (with 100–500 nm pore size). The factor of 1000 in the pore hierarchy and the synergy between the materials, that form a supercapacitor composite electrode with an integrated extended current collector, lead to both very high gravimetric and volumetric capacitances. In particular, values of 1474 F g−1 and 86 F cm−3 for a GF filling factor of 11% (leading to an estimated value of 782 F cm−3 for 100%), respectively, are obtained at a current density of 0.47 A g−1. Moreover, the composite electrode presents a capacitance retention of 83% after 15000 cycles. This excellent behavior makes the PANI-NFS/GF composite electrodes very attractive for high-performance supercapacitors.
MnO offers remarkably high theoretical capacity based on conversion reaction for lithium-ion batteries (LIBs). However, the low electronic conductivity and large volume changes of MnO have severely limited its applications. Due to the high conductivity of carbon nanotubes (CNTs), we synthesized a three-dimensional (3D) interconnected MnO/CNTs composite by a step-by-step method to solve the above issues. The obtained 3D interconnected MnO/CNTs composite has the advantages of high capacity of MnO and the excellent conductivity of CNTs, in which CNTs were connected with each other to form an interconnected network for the embedding of nanosized MnO particles. As a consequence, the prepared 3D interconnected MnO/CNTs composite shows a high capacity of 992 mA h g−1 at 0.2 A g−1 after 150 cycles and 893 mA h g−1 at 0.5 A g−1 after 300 cycles, demonstrating the potential of promising anode material for LIBs.
Boron containing ionogels were fabricated through chemical crosslinking of boron allyloxide with polyethylene glycol dimethacrylate in an ionic liquid electrolyte solution to obtain mechanically robust gels. Because of the relatively small concentration of crosslinking agent required to fully solidify the ionic liquid electrolyte, good characters of high ionic conductivity, high thermal stability, and good electrochemical stability were observed. A spectroscopic investigation of the boronic ionogels revealed that the lithium mobility was noticeably enhanced compared with ionogels fabricated without the boronic crosslinker, leading to promising Li-ion battery performance at elevated temperatures.
The search for more stable electrocatalyst materials for electrochemical energy conversion requires a fundamental understanding of the underlying degradation processes. Advanced characterization techniques like identical location transmission electron microscopy (IL-TEM) can provide invaluable insight into the stability of electrode materials on the nanoscale. In this review, the basic principles and the methodology of IL-TEM are described, and its capabilities are revealed by demonstrating the recent progress that has been achieved in research on the stability of fuel cell catalysts. Moreover, we provide future perspectives of the identical location approach towards implementing other electron microscopic and tomographic applications, which will help us to gain an even broader view of the degradation of electrocatalysts.
CuO nanosheet arrays freely standing on nickel foam are prepared via a template-free growth method. The morphology of CuO nanosheet arrays is examined by scanning and transmission electron microscopy and the phase structure of nanosheets is analyzed by X-ray diffraction spectroscopy. The supercapacitance of CuO nanosheet arrays is investigated by cyclic voltammetry, galvanostatic charge/discharge test and electrochemical impedance spectroscopy. The results show that the array of CuO nanosheets forms a uniform film of around 5μm in thickness on nickel foam skeleton. The film is composed of clusters of arrays of nanosheets with a thickness up to around 150nm. The CuO nanosheet arrays exhibit a specific capacitance of 569Fg−1 at a current density of 5mAcm−2 in 6.0moldm−3 KOH electrolyte. The capacitance loss is less than 17.5% after 500 charge/discharge cycles at 10mAcm−2 and with columbic efficiency higher than 93%.
External knowledge is crucial to cluster development. In an industrial cluster of a late-comer country, cluster networks are established based on the outsourcing relationship within the companies of advanced countries. However, it is an issue which is worth exploring whether the industrial clusters of late-comer countries can only rely on the advanced companies in acquisition of external knowledge. By adopting the case of Zhangjiang industrial cluster, this article has two objectives. Firstly, this study tries to understand where the knowledge source of companies comes from. Secondly, this research attempts to understand why this phenomenon exists through the examination of the development of integrated circuit industries for mobile phones. The results indicate that the telecommunications industry is related to national security and engenders enormous economic interests, and that local companies cooperate with each other. In addition, the government encourages the cooperation between local upstream and downstream companies to eliminate the constraints imposed by advanced companies. This cross-regional collaboration relies on the interactions among firms at a national level and the strong demand of the domestic market, which provides local companies with the opportunities to improve innovation capacities and techniques, thereby contributing to cluster development.
Background Obstructive sleep apnea (OSA) is a prevalent disorder with multiple consequences including negative effects on neurocognitive function. Several domains of cognitive function are impaired in OSA patients, but the mechanisms through which this sleep disorder results in impairment are not clear. Given the well-known effects of cortisol on cognitive function, in particular memory, the dysregulating effects of OSA on cortisol levels are hypothesized as a potential pathway leading to cognitive impairment. Methods Fifty-five participants with OSA (mean apnea-hypopnea index [AHI], 30.3) were assessed over 2days. Over a 24-h period, blood samples were collected every 2h to examine cortisol levels. The following night, sleep was monitored with polysomnography (PSG). Participants were given a battery of neurocognitive tests, which assessed seven cognitive domains. Results OSA severity assessed by oxygen desaturation index (ODI) was associated with 24-h cortisol levels. AHI, ODI, and nighttime cortisol levels were associated with global deficit scores (GDS) in cognitive functioning, particularly in domains of learning, memory, and working memory (P <.05 for all). Hierarchical linear regression analysis revealed that nighttime cortisol accounted for 9–16% of variance in learning (P =.018), memory (P =.003), and working memory (P =.016) domains, though apnea severity did not significantly predict any additional variance. Conclusions In our sample of patients with OSA, nocturnal cortisol levels were associated with neuropsychologic functioning above and beyond the influence of covariates and apnea severity. These findings suggest that OSA-related alterations in cortisol activity may partially explain the pathophysiology of neuropsychologic impairments in sleep apnea.
In order to develop safe lithium-ion batteries using Ni-based cathode active materials, such as LiNi x Mn(1−x)/2Co(1−x)/2O2, thermal stability is one of the most important requirements. We used XRD and TDS-MS in the first step of our study to elucidate the thermal stability and to improve it under anomalous high temperature conditions. We investigated the relationship between the thermal stability and cathode composition, especially for that of the nickel and lithium content. The XRD indicated that the crystal structure of electrochemically delithiated materials changed from a layered into a spinel structure followed by a rock-salt structure as the temperature rose. The TDS-MS indicated that these changes coincided with the release of oxygen from the cathode materials. We found that decreasing the lithium content and increasing the nickel content made the temperature of the crystal structure change and oxygen release lower, and thus, influenced the cathode composition.