batterydata/paper-abstracts huggingface dataset:
To replace conventional metal electrode, flexible carbon nanotube (CNT) sheet having excellent electrical properties is first applied as a current collector in all-solid-state lithium batteries, and its effect on the performance of all-solid-state lithium batteries are investigated. In the case of cells without the CNT sheet, gaps between the all-solid-state composite cathode and metal current collector (e.g., a conventional metal foil or coin cell) limits physical contacts which is not a trivial problem for the all-solid-state composite cathode. On the contrary, the CNT sheet makes intimate contact and provides a large interfacial contact area by filling the gaps. It is a great benefit in practical process viewpoint that this sufficient physical contact is achieved even without any polymeric binder. The greatly reduced interfacial contact resistance due to the intimate contact between the all-solid-state composite cathode and CNT sheet causes improvements in reversible capacity and high-rate discharge performance.
The process of filling electrolyte into lithium ion cells is time consuming and critical to the overall battery quality. However, this process is not well understood. This is partially due to the fact, that it is hard to observe it in situ. A powerful tool for visualization of the process is neutron imaging. The filling and wetting process of the electrode stack can be clearly visualized in situ without destruction of the actual cell. The wetting of certain areas inside the electrode stack can clearly be seen when using this technique. Results showed that wetting of the electrode stack takes place in a mostly isotropic manner from the outside towards a center point of the cell at very similar speed. When the electrolyte reaches the center point, the wetting process can be considered complete. The electrode wetting is a slow but rather steady process for hard case prismatic cells. It starts with a certain speed, which is reduced over the progress of the wetting. Vacuum can assist the process and accelerate it by about a factor of two as was experimentally shown. This gives a considerable time and cost advantage for designing the production process for large-scale battery cell production.
In this paper, effective and systematic steps in the mathematical simplification and reduction of physics-based lithium-ion (Li-ion) battery models to improve computational efficiency will be presented. The battery model used for simulations is an isothermal model proposed by Newman and Tiedemann [1] and Doyle et al. [2] which incorporates the concentrated solution theory, the porous electrode theory, and the variations in electronic/ionic conductivities and diffusivities. The simplified model is formulated by exploiting the nature of the model and the structure of the governing equations. Simulations show that the simplified model can reduce computational time significantly while still retaining the accuracy compared to the full-order rigorous model.
This study contributes to social trust research by examining the extent to which cross-group interaction provokes exclusionary reactions among trusters. Specifically, we examine whether unpleasant contact with ethnic outgroup members constrains the relationship between social trust and ethnic exclusionism among majority members. The analysis shows that: (a) social trust relates negatively to ethnic exclusionism, (b) unpleasant contact experiences relate positively to ethnic exclusionism, and (c) social trust is almost unrelated to ethnic exclusionism when contact experiences have been unpleasant. Inconsistent with “moralistic” perspectives, social trusters’ views of ethnic outgroup members are remarkably experience-based. To understand the “experiential effect”, we develop a tentative interpretation emphasizing the joint capacity of negative emotions and group membership salience to enhance the implications of unpleasant encounters among contacted trusters. The analysis is based on the 2014-European Social Survey, including 27,796 individuals and 21 countries. The concluding section discusses how our affect-salience interpretation adds to the experiential understanding of social trust and interethnic relations in contemporary nations.
Polymer electrolyte membrane fuel cells (PEMFC) and direct methanol fuel cells (DMFC) have found a wide variety of commercial applications. Their performance is essentially governed by the electrocatalyst support materials as they strongly influence the electrocatalyst performance, durability and efficiency. It is well known that carbonaceous support materials suffer from carbon corrosion (oxidation) especially at high potentials over time and thus alternative low-cost, high-performing and non-corrosive electrocatalyst support materials are urgently required. This review highlights the performance and issues associated with a variety of carbon based materials such as carbon nanotubes (CNT), carbon nanofibers (CNF), mesoporous carbon and graphene as well as non-carbonaceous based materials, e.g. titania, indium oxides, alumina, silica and tungsten oxide and carbide, ceria, zirconia nanostructures and conducting polymers catalyst support materials. Comparisons and advantages and disadvantages of the various supports are clearly described in this review.
An original Al-air semi-fuel cell (SFC) system, operating with hydrogen peroxide (H2O2) co-generation was developed. The cell design was optimized and operating conditions were selected in the comparative study of different of anion-exchange MA-40, AMI 7001S and cation-exchange MK-40, NAFION 117 membranes, gas-diffusion electrodes (GDE) Black Pearls 2000 (BP 2000), Vulcan XC-72 (XC-72), nature and concentration of electrolytes (NaOH, KOH and NaCl). Their influence on electric characteristics (current density and generated power) and current efficiency of H2O2 generation was studied. The best results were achieved were using BP 2000 GDE in the SFC divided by anion-exchange membrane (AEM) with 6M KOH as an electrolyte. However, some acceptable results were achieved even using dilute chloride solutions. Finally, the scale-up experiments showed that the specific electric characteristics of the fuel cell (FC) enhanced at 15-fold increase of the electrode area.
The current generation is not only facing the shortage of fossil fuels in the near future, but also is responsible for preserving the environment for future generations. As a result, the development of clean energy systems is becoming an urgent focus for the research community. Metal air batteries have attracted much attention due to their extremely high energy density, and the rechargeability which is directly governed by the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, we present a new class of hybrid bi-functional catalyst consisting of porous nanorod perovskite La0.5Sr0.5Co0.8Fe0.2O3 (LSCF-PR) combined with nitrogen-doped reduced graphene oxide (NRGO) active towards both ORR and OER. The novel morphology of LSCF-PR is prepared by an electrospinning method, and incorporated into NRGO sheets. Electron microscopy reveals interesting composite morphology in which LSCF-PR is embedded between the sheets of NRGO, forming an efficient LSCF-PR/NRGO composite morphology for the electrochemical oxygen reactions. Electrochemical testing of the LSCF-PR/NRGO composite in alkaline medium results in excellent ORR and OER catalytic activities, verifying the effective combination for bi-functionality. LSCF-PR/NRGO presents not only a comparable or superior performance to state-of-the-art Pt/C catalyst for ORR or OER, respectively, but also better durability. These results highlight the applicability of LSCF-PR/NRGO composite having unique and efficient morphology as a promising bi-functional catalyst for metal air battery applications.
This work demonstrates a novel and facile route for preparing graphene-based composites comprising of metal oxide nanoparticles and graphene. A graphene nanosheet–bismuth oxide composite as electrode materials of supercapacitors was firstly synthesized by thermally treating the graphene–bismuth composite, which was obtained through simultaneous solvothermal reduction of the colloidal dispersions of negatively charged graphene oxide sheets in N,N-dimethyl formamide (DMF) solution of bismuth cations at 180°C. The morphology, composition, and microstructure of the composites together with pure graphite oxide, and graphene were characterized using powder X-ray diffraction (XRD), FT-IR, field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), thermogravimetry and differential thermogravimetry (TG–DTG). The electrochemical behaviors were measured by cyclic voltammogram (CV), galvanostatic charge–discharge and electrochemical impedance spectroscopy (EIS). The specific capacitance of 255Fg−1 (based on composite) is obtained at a specific current of 1Ag−1 as compared with 71Fg−1 for pure graphene. The loaded-bismuth oxide achieves a specific capacitance as high as 757Fg−1 even at 10Ag−1. In addition, the graphene nanosheet–bismuth oxide composite electrode exhibits the excellent rate capability and well reversibility.
The electrochemical performance of aqueous rechargeable lithium battery (ARLB) with LiV3O8 and LiMn2O4 in saturated LiNO3 electrolyte is studied. The results indicate that these two electrode materials are stable in the aqueous solution and no hydrogen or oxygen produced, moreover, intercalation/de-intercalation of lithium ions occurred within the range of electrochemical stability of water. The electrochemical performance tests show that the specific capacity of LiMn2O4 using as the cathode of ARLB is similar to that of ordinary lithium-ion battery with organic electrolyte, which works much better than the formerly reported. In addition, the cell systems exhibit good cycling performance. Therefore, it has great potential comparing with other batteries such as lead acid batteries and alkaline manganese batteries.
This study characterizes the composition of plastic frames and printed circuit boards from end-of-life mobile phones. This knowledge may help define an optimal processing strategy for using these items as potential raw materials. Correct handling of such a waste is essential for its further “sustainable” recovery, especially to maximize the extraction of base, rare and precious metals, minimizing the environmental impact of the entire process chain. A combination of electronic and chemical imaging techniques was thus examined, applied and critically evaluated in order to optimize the processing, through the identification and the topological assessment of the materials of interest and their quantitative distribution. To reach this goal, end-of-life mobile phone derived wastes have been systematically characterized adopting both “traditional” (e.g. scanning electronic microscopy combined with microanalysis and Raman spectroscopy) and innovative (e.g. hyperspectral imaging in short wave infrared field) techniques, with reference to frames and printed circuit boards. Results showed as the combination of both the approaches (i.e. traditional and classical) could dramatically improve recycling strategies set up, as well as final products recovery.
The electrode morphology and electrochemistry of silicon nanocomposite electrodes containing either carboxymethyl cellulose (CMC-Na) or poly(acrylic acid) (PAA) binders are examined in context of their working surface area. Using porous carbon (Ketjenblack) additives, coatings with poor adhesion properties and deep cracks were obtained. The morphology is also reflected in the electrochemical behavior under capacity-limited conditions. Mapping the differential capacity versus potential over all cycles yields detailed insights into the degradation processes and shows the onset of cell failure with the emergence of lithium-rich silicon alloys at low potentials, well before capacity fading is observed. Fading occurs faster with electrodes containing PAA binder. The surface area of the electrode components is a major cause of increased irreversible reaction and capacity fade. Synchrotron-based X-ray photoelectron spectroscopy on aged, uncycled electrodes revealed accelerated conversion of the native SiOx-layer to detrimental SiOxFy in presence of Ketjenblack. In contrast, a conventional carbon black better preserved the SiOx-layer. This effect is attributed to preferred adsorption of binder on high surface area electrode components and highlights the role of binders as ‘artificial SEI-layers’. This work demonstrates that optimization of nanocomposites requires careful balancing of the surface areas and amounts of all the electrode components applied.
The distribution of the photovoltaic systems is faced with technological and economic problems, and the businesses and corporations feel burdened by the photovoltaic system’s dubious economic value and high construction costs. Thus, not too many enterprises or private citizens have been participating in the business of installing photovoltaic systems. Moreover, because of lack of skills in integrating engineering and architectural design, they are experiencing difficulties even in using the technologies that have already been developed and available for application. To provide the basic information and specific data required for making the guidelines for developing photovoltaic technologies, this paper evaluates the system types, the actual state of operation, and performance of the two photovoltaic systems that are installed in Kiemyung University’s Osan Building and Dongho Elementary School in Daegu Metropolitan City.
The massive introduction of plug-in electric vehicles (PEVs) into low voltage (LV) distribution networks will lead to several problems, such as: increase of energy losses, decrease of distribution transformer lifetime, lines and transformer overload issues, voltage drops and unbalances. In this context, this paper proposes a new multi-objective optimization algorithm in order to reduce the mentioned problems. At the same time, users’ interests in terms of charging cost and privacy have been taken into account. The proposed multi-objective optimization is based on minimizing the load variance and charging costs by using the weighted sum method and fuzzy control. The use of vehicle to grid (V2G) concept and load forecast uncertainties have been also considered. Furthermore, an innovative method for mitigating voltage unbalances has been developed. The effectiveness of this methodology has been tested using real data of a LV distribution network, located in Borup (Denmark). Simulation results show that this approach can reduce both energy losses and charging costs as well as it allows a high PEV penetration rates (PEV-PR).
Psychological distress in primary malignant brain tumour (PMBT) patients is associated with poorer outcomes. Radiotherapy (RT) often induces side effects that significantly influence patients’ quality of life (QoL), with potential impact on survival. We evaluated distress, anxiety, depression, and QoL over time to identify patients with difficulties in these areas who required more intense psychological support.
The high capacity of Li-rich layered cathode materials have attracted great attention for the greater energy density lithium ion (Li-ion) batteries, but the understanding of knowledge associated with electrochemical behaviours are still needed to improve their performances further. In this study, different amount of Co content is designed in Li-rich layered compounds (0.5Li2MnO3·0.5LiMn0.5-xNi0.5-xCo2xO2, 0 ≤ x ≤ 0.2), and the stepwise electrochemical activation process is applied to explore the features. We discover that the substitution of Co3+ ions can accelerate the electrochemical activation of Li2MnO3 component, and the Co-doped compound delivers much higher capacities even they suffer an apparent voltage decay comparing to the Co-free one. Besides, a fast metal ions migration exists (e.g., from the metastable tetrahedral site to the lower energy cubic site) in initial dozens of cycles (e.g., 30 cycles at 0.1C); thereafter, they likely return to the original octahedral site, as demonstrated in the voltage decay and hysteresis analysis.
Dental wastes are regulated under medical waste control regulations in most countries. Even though the quantity of hazardous wastes in dental solid wastes is a small proportion, there is still cross infection risk and potential danger for environment associated with mismanaged wastes. For this reason, knowledge of waste composition and development of proper management alternatives are necessary. In this study, the composition of solid wastes coming from eight clinics of the dental school of a University hospital in Turkey is examined. Although the waste has some variations between the two samplings, the general picture is such that the major components remain pretty much the same (in terms of%) for a fixed clinic. The composition of waste changes from one clinic to the other as expected. However, one can deduce from the data obtained that at about 35%, rubber gloves constitute close to the half of the total solid waste in almost all the clinics. Other major component is paper forming approximately 30% of the solid waste. In general, total waste coming from the clinics is related with the number of procedures conducted on patients at the clinics. Only a small fraction of the waste is hazardous indicating that at Hacettepe University School of Dentistry, hazardous waste collection rules are obeyed in most of the times.
To get insight in the impact of fish and fat intake in the prevention of accelerated cognitive decline with ageing, we tested associations between fish and different fat intakes and 5-year change in cognitive functions.
In this paper, the theoretical study of cyclic reciprocal derivative chronopotentiometry (CRDCP) for totally reversible electrode processes with symmetrical and unsymmetrical programmed currents is presented. The main viewpoints are: (1) for symmetrical programmed current, the amplitudes of the successive currents are the same, i.e. I(t)=(−1) i+1 I 0, whereas the transition times of each current step, τ i , have different values. The properties of the dt/dE–E curves corresponding to each current cycle also differ a lot. (2) For unsymmetrical programmed current proposed in this work for the first time, the applied current successively reversed at each transition time steps to different amplitude. The use of this unique programmed current is advantageous versus symmetrical programmed current since the transition times obtained are equal to each other anticipatively, and the dt/dE–E curves also coincide with each other for the successive cycles. In this case, the results obtained in CRDCP are almost similar to those of cyclic voltammetry (CV). The characteristic parameters obtained in the dt/dE–E curves in both cases are quantitatively related to the species concentrations adjacent to the electrode surface and afford simple diagnosis criteria to characterize the reversibility of electrode processes. Properties of reversible electrode processes have also been further studied through the use of more than one current cycle.
Objective: To explore motor control reorganization in a 40-year-old, left-handed patient with perinatally acquired mirror movements. Methods: We performed simultaneous bilateral recordings of motor evoked potentials (MEPs) following focal transcranial magnetic stimulation (fTMS) and of central silent period (cSP) during unilateral voluntary contraction in abductor pollicis brevis (APB) and abductor digiti minimi (ADM) muscles. Results: For both muscles the MEP study showed bilateral fast-conducting corticospinal projections from the right undamaged hemisphere, and residual contralateral projections from the left hemisphere. The cSP findings differed in the two muscles: the mirror phenomenon was bilateral in the ADM, but present only on the right side in the APB muscles; the mirror activity of right ADM and APB muscles was inhibited only by fTMS of the ipsilateral right motor cortex; the mirror phenomenon in the left ADM muscle was inhibited only by fTMS of the contralateral right motor cortex. Conclusions: Mirror movements of right APB and ADM muscles were sustained by the ipsilateral connections from the undamaged motor cortex, while the mirror phenomenon in the left ADM muscle could be explained by hypothesizing a bilateral activation of motor cortices. This previously unreported electrophysiological picture demonstrates that different patterns of motor control may realize after perinatal cerebral lesions, even in different distal muscles of the same patient.
A new approach to fabricating planar micro-fuel cells with flow channels and catalyst layers fully integrated into the Nafion membrane is presented. The microfabrication approach leverages the use of electron beam lithography for pattern creation, dry etching for pattern transfer and aspect ratio manipulation, and masking for selective electro-catalyst layer deposition. Sputtered Pt and conventional Pt/C served as catalyst layers for the fabricated cells which were tested under humid and dry conditions. The sputtered cell had the best overall performance. The maximum power densities were respectively 11.2 and 20.8 mW cm−2 for the dry and humidified conventional catalyst based cells, and 3.0 and 22.1 mW cm−2 for the sputtered Pt cells. Based on these results, the authors conclude that the observed performance is limited by ohmic polarization.
Iron single-atom catalyst in form of iron-nitrogen-carbon structure possesses the excellent catalytic activity in various chemical reactions. However, exploring a sustainable and stable single-atom metal catalyst still faces a great challenge due to low yield and complicated synthesis. Here, we report a functional multi-wall carbon nanotubes modified with iron phthalocyanine molecules via a liquid chemical reaction and realize the performance of similar single-atom catalysis for oxygen reduction reaction. A serial of characterizations strongly imply the structure change of iron phthalocyanine molecule and its close recombination with multi-wall carbon nanotubes, which are in favor of ORR catalysis. Compared to commercial platinum-carbon catalyst, composites exhibit superior activity for oxygen reduction reaction with higher half-wave potential (0.86 V), lower Tafel slope (38 mV dec−1), higher limiting current density and excellent electrochemical stability. The corresponding Zinc-air battery also presents higher maximum power density and discharge stability. Therefore, these findings provide a facile route to synthesize a highly efficient non-precious metal carbon-based catalyst.
Electrochemical power sources that offer high energy and power densities and, can also withstand a harsh temperature range have become extremely desirable in applications ranging from civilian portable electronic devices to military weapons. In this report, we demonstrated a wide temperature withstanding supercapacitor which can be operated from 100°C to −40°C within a voltage window from −2V to 2V. The performance of the supercapacitor coin cells, assembled with nanostructured activated carbon fabric (ACF) as the electrode material and 1M tetraethylammonium tetrafluoroborate (TEABF4) in polypropylene carbonate (PC) solution as the electrolyte, was systematically studied within the set temperature window. The ACF supercapacitor yielded ideal rectangular shapes in cyclic voltammograms within 0–100°C with an average mass capacitance of 90Fg−1 and, 60Fg−1 at −25°C. The capacitance was still over 20Fg−1 at the extremely low temperature of −40°C. Another exciting feature of the ACF supercapacitors was that they resumed their room temperature capacitance when cooled from 100°C and defrosted from −40°C, demonstrating an excellent repeatability and stability. The charge–discharge behavior of the ACF supercapacitors showed long-cycle stability at extreme temperatures. These high electrochemical performances make this type of supercapacitors very promising in many practical applications.