batterydata/paper-abstracts huggingface dataset:
Lithium sulfur battery (LSB) offers several advantages such as very high energy density, low-cost, and environmental-friendliness. However, it suffers from serious degradation of its reversible capacity because of the dissolution of reaction intermediates, lithium polysulfides, into the electrolyte. To solve this limitation, there are many studies using graphene-based materials due to their excellent mechanical strength and high conductivity. Compared with graphene, graphene oxide (GO) contains various oxygen functional groups, which enhance the reaction with lithium polysulfides. Here, we investigated the positive effect of using GO mixed with carbon black on the performance of cathode in LSB. We have observed a smaller drop of capacity in GO mixed sulfur cathode. We further demonstrate that the mechanistic origin of reversibility improvement, as confirmed through CV and Raman spectra, can be explained by the stabilization of sulfur in lithium polysulfide intermediates by oxygen functional groups of GO to prevent dissolution. Our findings suggest that the use of graphene oxide-based cathode is a promising route to significantly improve the reversibility of current LSB.
Following the Fukushima accident, the safety features of Nuclear Power Plants (NPP) are being re-examined worldwide including India to demonstrate capabilities to cope with severe accidents. In order to restore public confidence and support for nuclear power, it is felt necessary to design future NPPs with near zero impact outside the plant boundary and thus enabling elimination of emergency planning in public domain. Authors have identified a set of safety features which are needed to be incorporated in advanced reactors to achieve this goal. These features enabling prevention, termination, mitigation and containment of radioactivity for beyond design basis accidents arising from extreme natural events are essential for achieving the goal of elimination of emergency planning in public domain. Inherent safety characteristics, passive and engineered safety features to achieve these functions are discussed in this paper. Present trends and future developments in this direction are also described briefly.
Mg2Ni–x mol% Mg3MnNi2 (x =0, 15, 30, 60, 100), the novel composite alloys employed for hydrogen storage electrode, have been successfully synthesized by a method combining electric resistance melting with isothermal evaporation casting process (IECP). X-ray diffraction (XRD) analysis results show that the composite alloys are composed of Mg2Ni phases and the new Mg3MnNi2 phases. It is found on the electrochemical studies that maximum discharge capacities of the composite alloys increase with the increasing content of the Mg3MnNi2 phase. The discharge capacity of the electrode alloy is effectively improved from 17mAhg−1 of the Mg2Ni alloy to 166mAhg−1 of the Mg3MnNi2 alloy. Among these alloys, the Mg3MnNi2 phase possesses a positive effect on the retardation of cycling capacity degradation rate of the electrode materials. Cyclic voltammetry (CV) results confirm that the increasing content of the Mg3MnNi2 phase effectively improves the reaction activity of the electrode alloys. Surface analyses indicate that the Mg3MnNi2 phase can enhance the anti-corrosive performance of the particle surface of these composite alloys.
An efficient, durable and low cost air cathode with low polarization between the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is essential for a high performance and durable secondary zinc-air battery. Different valence states and morphologies of MnxOy catalysts were synthetized via thermal treatment of EMD (generating Mn2O3 and Mn3O4) and acid digestion of synthetized Mn2O3 (producing α-MnO2) in order to develop an efficient Bifunctional Air Electrode (BAE). Change in the ratio H+ to Mn2O3 during the acid digestion affects the sample microporosity, the crystallographic plane distribution, as well as the physical and chemical adsorbed water which was related to defects, i.e. cation vacancies (Mn4+) and Mn3+. These characteristics were discussed and linked to the electrocatalytic activity. The best ORR performing catalyst was that with the higher surface water content (associated to material BET surface area) and a (310) surface as the 2nd more contributing plane (after 211). On the other hand, the catalyst with the higher structural water and with (110) and (200) crystallographic planes being the most intensity contributors (after 211) was the most OER active material. In this work, it was able to find a relationship between catalyst structure and air-efficiency through a volcano-like relationship between air-efficiency and surface water content. Air-efficiency (also take as round-efficiency discharge/charge in battery context) can be taken as a good descriptor of potentially good materials for Zn-Air secondary batteries technology. In this term, we were able to prepare a Bifunctional Air Electrode based on the selected α-MnO2 sample which demonstrated a round-efficiency of 53%, a ΔV around 1V and a neglected loss of the charge potential (about 2.1V) over the entire lifecycle test (more 200 cycles over 30hours) with a capacity retention superior to 95%.
With the lowest access to electricity in the world, the country of Liberia, West Africa, has efforts underway for electrification through a fossil based centralized scheme around its capital city and possible connections to the larger Western Africa Power Pool network. These plans leave a large part of the rural population with no access to electricity. This work analyzes the potential of decentralized generation to provide electricity to the rural Liberian population. The suppressed demand of the rural population is calculated at 235GWh/yr. There is sufficient renewable energy potential to supply this demand. The capital costs and electricity prices of decentralized generation with different fuels are calculated and compared to the ability and willingness to pay of rural Liberians. Small diesel units have the lowest capital cost but photovoltaic, small hydropower and small biomass projects provide lower electricity prices. Biomass and small hydro electricity are affordable for Liberians at $0.08/kWh and $0.11/kWh respectively. Diesel and photovoltaic, with levelized cost of electricity of $0.62/kWh and $0.33/kWh respectively, exceed Liberians' willingness to pay. Centralized and decentralized electricity developments are not mutually exclusive; both may be used within a comprehensive electrification plan. Decentralized generation with emphasis on rural areas can complement the existing plans to achieve the Government of Liberia's goal of universal access to electricity, providing social equity and economic progress. In order to become a reality, rural decentralized electrification will need policy support and focused funding.
A composite bifunctional catalyst (MnO2–NCNT) was prepared from manganese dioxide (MnO2) nanotubes and nitrogen-doped carbon nanotubes (NCNT) for the purpose of oxygen reduction (ORR) and evolution (OER) catalysis in the rechargeable zinc-air battery. From the half cell test, the MnO2–NCNT composite illustrated excellent activities towards ORR and OER in alkaline conditions. Based on the battery test, the composite catalyst displayed outstanding discharge and charge performance while maintaining good stability. In both cases, the marked performance improvements from MnO2–NCNT compared favourably to the NCNT and MnO2, which are the constituents of the composite. In particular, MnO2–NCNT exhibited improved half wave potential by 220mV compared to MnO2 and much superior OER stability compared to NCNT based on the rotating ring disk voltammetry results. According to battery test, MnO2–NCNT decrease the battery resistance by 34% and concurrently improved the durability, discharge and charge performance in comparison to the MnO2 nanotubes.
Graphene paper that exhibits an excellent stabilized capacity, as high as 1300 mAh g−1 at a current rate of 60mAg−1, as a lithium ion battery anode is fabricated and evaluated. The few-layer graphene used to make the graphene paper is prepared via the thermal reduction of graphite oxide. The graphene is then modified by a novel method utilizing inherent defects, namely epoxy groups, on the graphene as active sites for a reaction with methanol, 1-butanol, 1-hexanol, and 1-octanol. The density values and X-ray diffraction patterns obtained for the graphene paper demonstrate that the alkyl brushes on the graphene sheets expand the d-spacing and hinder close restacking of the sheets, thereby inducing the formation of extra cavities within the paper. This loose packing due to the alkyl brushes increases sensitively as the alkyl chain length of the alcohol becomes longer. The lithium ion insertion capacity of a graphene paper electrode at the first cycle also increases with the alkyl chain length. However, fading of the capacity at early charge/discharge cycles is accelerated by the modification process because of electrolyte penetration into the gallery and the acceleration of protective solid electrolyte interface film formation due to looser packing. The paper composed of graphene modified with 1-butanol rather than shorter or longer alcohols exhibits the best reversible storage capacity, more than two-fold higher when compared to that of pristine graphene paper, due to a compromise between two conflicting effects on the reversible storage capacity by long alkyl brushes. The tensile properties and electrical conductivity of the graphene papers are also examined.
A mathematical model is developed to study the effect of the potential drop across the SEI layer on the growth of the SEI layer and the subsequent capacity fading in a lithium ion battery. The model assumes that the formation of the SEI layer is principally because of the diffusion and migration of lithium ions across the SEI layer. Film formation and capacity fading in a lithium ion battery is studied as a function of diffusion of lithium ions, kinetics of reaction at the interphase and potential drop across the SEI layer. Capacity loss is found to increase with increasing potential drop across the SEI layer. Capacity fade is found to be very dependent on the kinetics of the reaction as compared to diffusion. Model results are found to compare very well with experimental data.
The economic viability of hydrodeoxygenation process using Camelina, Carinata and Jatropha feedstocks for aviation biofuel production was evaluated for two product profiles: (i) maximum diesel production and (ii) maximum jet fuel production (HRJ).
Direct borohydride fuel cells (DBFC) exhibit some potential regarding the powering of small portable electronic devices, thanks to their high energy density as well as the facile and safe storage of borohydride salts. However, DBFC are hindered because (i) the borohydride oxidation reaction (BOR) is complex, (ii) its mechanism imperfectly determined yet and (iii) no practical electrocatalyst exhibits both fast BOR kinetics and high faradaic efficiency. In this context, we characterized the BOR mechanism for polycrystalline bulk gold (a classical model BOR electrocatalyst) in the rotating disk electrode (RDE) setup. Modeling cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) data, we propose a simplified reaction pathway, the theoretical behavior of which agrees with the experimental findings. This pathway includes at least a first irreversible electrochemical step (E) for BH4 − oxidation, which competes with the electrochemical adsorption reaction (EAR) of OH− anions at high potentials.
The poly(o-anisidine)–sulfuric acid–glucose oxidase (POA–H2SO4–GOx) electrode has been investigated in the present work. Platinum electrode was used for the synthesis of poly (o-anisidine)–sulfuric acid (POA–H2SO4) film using galvanostatic method with 0.2 M o-anisidine, 1.0 M H2SO4 solution, 1.0 pH and 2 mA/cm2 applied current density. The synthesized film was characterized using electrochemical technique, conductivity measurement, UV–visible spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy. GOX was immobilized on synthesized POA–H2SO4 film by cross-linking via glutaraldehyde in phosphate and acetate buffer. The Michaelis–Menten constant (
Hierarchically porous hybrids of strongly coupled nitrogen-doped porous carbons and graphene aerogel (NPC-GA) are fabricated through the solid-state oxidation polymerization and carbonization of m-phenylenediamine on the interconnected macroporous frameworks of GA. The hierarchically porous hybrids provide abundant storage sites and short transport paths for electrolyte ions. By adjusting the pyrolysis temperature, the specific surface areas and nitrogen content of NPC-GA can be easily modified, further influencing the electrochemical performance of the hybrids. In a three-electrode system, NPC-GA electrode shows high specific capacitance of 608Fg−1 at 0.1Ag−1 in 1M H2SO4. An all-solid-state flexible supercapacitor based on NPC-GA delivers superior energy density (12.4 Wh Kg−1) and power density (2432W Kg−1) as well as good cycling stability (92% specific capacitance retention after 10 000 cycles).
Traditional transvenous approach for permanent cardiac pacing can be associated with significant acute and chronic complications related partly to either the insertion of transvenous lead or subcutaneous placement of pacemaker device. We summarize the current status of a novel self-contained leadless cardiac pacemaker in the first-in-human and subsequent series of feasibility studies in patients indicated for ventricular rate-responsive pacing (VVI). Using a femoral venous approach, the device is implanted at the right ventricular apical septum region. We describe the technical and clinical characterization of this innovative technology. Two different systems of leadless pacemakers are currently implanted to the patients. Up to now, the electrical parameters, such as pacing thresholds, sensing parameters, and pacing impedances, either improved or remained stable within the accepted range. In this chapter, we also discuss the potential benefit for the future, but in summary, all available data demonstrate the feasibility of leadless cardiac pacing.
Cobalt hydroxide nano-flakes are successfully synthesized by a facile chemical precipitation method. Electrochemical characterization is performed using cyclic voltammetry, chronopotentiometry and impedance spectroscopy, respectively. These cobalt hydroxide nano-flakes maintain high utilization at high rates of discharge. A maximum specific capacitance of 735Fg−1 can be achieved in 2M aqueous KOH with the potential range from −0.2 to 0.4V (vs. SCE) in a half-cell setup configuration for the nano-flakes Co(OH)2 electrode, suggesting its potential application in electrochemical capacitors. Furthermore, the effect of annealing temperatures on the electrochemical capacitance characteristics is also been systematically explored.
The severe lithium polysulfide (LiPS) shuttling and self-discharge behavior of lithium-sulfur (Li-S) batteries remarkably hinder their practical application. The construction of interlayer is an effective strategy to obstruct the diffusion of LiPS. However, the simplex physical block or chemical absorption of monotonous interlayer is difficult to reuse sulfur species, reduce impedance and restrain self-discharge of the Li-S battery simultaneously. In this study, a multicomponent sandwich-type interlayer was integrated by vanadium disulfide and carbon nanotubes composite (VS2/CNT), carbon nanofibers (CNF) substrate and graphene coating layer. The VS2/CNT presented strong affinity towards LiPS and effectively restrained the self-discharge of Li-S batteries. The CNF substrate as supporting framework increased the wettability of electrolyte and reduced the diffusion impedance of lithium ion. The graphene coating layer acting as the second collector effectively recovered the inactivated sulfur species. The multiple components of VS2/CNT adsorbent, CNF substrate and graphene coating layer exhibited favorable synergetic effects to suppress the LiPS shuttling and self-discharge of Li-S batteries. Besides, this interlayer endowed Li-S batteries with boosted redox kinetics and outstanding rate performance. The specific capacities at 0.1, 1 and 10 C were 1525, 834 and 621 mAh g−1, respectively. More importantly, the Li-S batteries with this multicomponent interlayer performed a high residual capacity of 605 mAh g−1 after 1145 cycles at 1 C. Even at a high sulfur loading of 5.6 mg cm−2, the cell still had high capacity of 1150 mAh g−1 and 750 mAh g−1 at 0.1 C and 0.3 C, respectively. The synergetic effects of multicomponent sandwich-type composite interlayer provided a new strategy for ultra-small self-discharge and stable of Li-S batteries.
Since conventional audio-video teleconferencing systems have reached their limits, the needs of integrating new sensations to improve users’ telecommunication experience are growing. Haptics, the sense of touch, which includes handshake, comforting hug, encouraging pat, and other physical contacts, is important to interpersonal communication, as it allows people to express and receive intimate affection, intention or emotion efficiently. Motivated by some haptic telecommunication softwares, this paper presents an innovative webcam-based touchscreen to further increase people’s degree of immersion with the haptic video chat system at a more reasonable price. With our webcam-based touchscreen, the user could directly use his/her bare hand to touch the image of the person who he/she is chatting with, instead of controlling a haptic device as the medium to realize indirect touch. This paper also gives details of the touchscreen method and our proposed mathematical models for touch position calculation. Experimental results show that our system is accurate and robust, while maintaining high compatibility with conventional audio-video teleconferencing systems for combination. With our haptic jacket, the passive user can feel the touch of the active user at the right position. Finally, we draw the conclusions and talk about future work.
To date, most of the research on electrodes for lithium sulfur batteries has been focused on the nanostructured sulfur cathodes and achieves significant success. However, from the viewpoint of manufacturers, the nanostructured sulfur cathodes are not so promising, because of the low volumetric energy density and high cost. In this work, we obtained the low-cost, scalable, eco-friendly mass production of edge-functionalized acetylene black-sulfur (FAB-S) composites by high-energy ball-milling technique for lithium sulfur batteries. The as-prepared FAB-S composite can deliver a high initial discharge capacity of 1304mAh/g and still remain a reversible capacity of 814mAh/g after 200 cycles at a charge-discharge rate of 0.2C in the voltage range of 1.7–2.7V. The observed excellent electrochemical properties demonstrate that the cathodes obtained by the facile high-energy ball-milling method as the cathode for rechargeable Li−S batteries are of great potential because it used the sole conductive additive acetylene black (AB). Such improved properties could be attributed to the partially exfoliation of AB, which not only keeps the AB's inherent advantage, but also increases the specific surface area and forms chemical bonds between carbon and sulfur, resulting in the accumulation of the polysulfides intermediate through both the physical and chemical routes.
An easy, quick and low cost hydrothermal synthesis was developed to prepare high surface area phospho-olivine LiFePO4 powders to be used as cathode material for Li-ion batteries. The samples were prepared in double distilled water starting from commercial LiOH, FeSO4, H3PO4 and using solutions with different concentrations of a surfactant compound (CTAB), in order to increase the specific surface areas, obtaining powders with very small grain size. The structural, morphological and electrochemical properties were investigated by means of X-ray powder diffraction (XRPD), ICP-AES, BET method, scanning electron microscopy (SEM) and constant current charge–discharge cycling. The electrochemical performances of LiFePO4 prepared in this manner showed to be positively affected by the presence of CTAB during synthesis, showing capacities near the theoretical value, only slightly affected by the discharge regime (from C/20 to 10C).
Cs0.86(NH4)1.14SO4Te(OH)6 supported by anodic alumina membranes (AAMs) has been characterized for the first time in H2/O2 fuel cell. The fabricated membrane electrode assemblies are able to produce peak power densities in the range 15–30mWcm−2 under mild conditions (room temperature, low humidity and low Pt loading) and show an increased durability with cycling with respect to previous results obtained with AAM-based fuel cell. The physico-chemical characterization of the electrolytes has been carried out through X-ray diffractometry, scanning electron microscopy and micro-raman analysis. An estimation of the composite membranes conductance under fuel cell operation has been carried out from I–V characteristics and EIS measurements at room temperature.
Clinical Schizophrenia has eluded precise description because of its protean phenotypic manifestations and variable clinical course, a variability that also makes it difficult to discover genetic linkages. Co-familial traits have higher recurrence risk rates than schizophrenia itself and might serve as pointers to the underlying physiology of schizophrenic illness. A dysfunction of smooth pursuit eye movements is one such co-familial trait that occurs in about 40 to 80% of schizophrenic patients and about 25 to 40% of their first degree relatives. The eye movement abnormality appears only when the subject tracks a moving target. We have traced this abnormality to a deficit in velocity sensitivity, a function that is regulated by a specific central nervous system network that includes the middle temporal and medial superior temporal areas of the extra-striate cortex. The higher familial recurrence risk of abnormal eye tracking, compared with that of clinical schizophrenia (about 5 to 8%), suggests that schizophrenic psychosis may be the rare form of a more prevalent disorder whose symptoms are much milder and more benign than the cognitive and behavioral disturbances of the clinical psychosis. From this vantage point, abnormal eye tracking can be viewed as one pleiotropic manifestation of schizophrenia, considered broadly, just as the café-au-lait spots of neurofibromatosis are a more benign and more frequent manifestation of that disease than are the neurofibromata.
Contrasting sharply with a recent trend in DSGE modeling, we propose a business cycle model where frictions and shocks are chosen with parsimony. The model emphasizes a few labor-market frictions and shocks to monetary policy and technology. The model, estimated from U.S. quarterly postwar data, accounts well for important differences in the serial correlation of the growth rates of aggregate quantities, the size of aggregate fluctuations and key comovements, including the correlation between hours and labor productivity. Despite its simplicity, the model offers an answer to the persistence problem (Chari et al., 2000) that does not rely on multiple frictions and adjustment lags or ad hoc backward-looking components. We conclude modern DSGE models need not embed large batteries of frictions and shocks to account for the salient features of postwar business cycles.