batterydata/paper-abstracts huggingface dataset:
Solid waste generation in sensitive tourist areas of the Indian Himalayan region is approaching that of some metro cities of the country. The present study showed ∼288 g waste generation visitor−1 day−1 compared with the nation-wide average of 350 g capita−1 day−1. About 29 metric tonnes (MT) solid waste is generated along a distance of about 19-km trek (a stretch of land or distance between two or more places covered by a walk) during a 4-month tourist season every year. Treks and trek stalls are the two major places where the visitors generate solid waste. Waste estimated from stalls accounted for about 51% by weight of the total waste generation in the trekking region. The native villagers generally construct stalls every year to meet the requirement of visitors going to Valley of Flowers (VOF) and Hemkund Sahib. The average annual results of 2 years (or equivalent to the average of one, 4-month tourist season for the region) showed non-biodegradable waste (NBW) to be 96.3% by weight whereas biodegradable waste (BW) amounted to merely 3.7%. From management point of view of the government, 96% NBW could easily be reused and recycled. Nevertheless, the need is to manage this waste by bringing it from the trekking areas to the road head (Govind Ghat) first and then to transport it to adjacent recycling centers. Cold drink glass bottles (68%), plastic (26%) and metal (2%) were the major items contributing to non-biodegradable waste. The remaining organic waste could be used as feedstock for composting. A well coordinated effort of public participation is necessary at all the levels for managing waste. There is a need to educate the visitors to instill in them the habit of considering discarded waste as potentially valuable and manageable.
A novel computer aided manufacturing (CAM) method for electrocorticography (ECoG) microelectrodes was developed to be able to manufacture small, high density microelectrode arrays based on laser-structuring medical grade silicone rubber and high purity platinum. With this manufacturing process, we plan to target clinical applications, such as presurgical epilepsy monitoring, functional imaging during cerebral tumor resections and brain-computer interface control in paralysed patients, in the near future. This paper describes the manufacturing, implantation and long-term behaviour of such an electrode array. In detail, we implanted 8-channel electrode arrays subdurally over rat cerebral cortex over a period of up to 25 weeks. Our primary objective was to ascertain the electrode’s stability over time, and to analyse the host response in vivo. For this purpose, impedance measurements were carried out at regular intervals over the first 18 weeks of the implantation period. The impedances changed between day 4 and day 7 after implantation, and then remained stable until the end of the implantation period, in accordance with typical behaviour of chronically implanted microelectrodes. A post-mortem histological examination was made to assess the tissue reaction due to the implantation. A mild, chronically granulated inflammation was found in the area of the implant, which was essentially restricted to the leptomeninges. Overall, these findings suggest that the concept of the presented ECoG-electrodes is promising for use in long-term implantations.
Recently, great interest has been aroused in flexible/bendable electronic equipment such as rollup displays and wearable devices. As flexible energy conversion and energy storage units with high energy and power density represent indispensable components of flexible electronics, they should be carefully considered. However, it is a great challenge to fabricate flexible/bendable power sources. This is mainly due to the lack of reliable materials that combine both electronically superior conductivity and mechanical flexibility, which also possess high stability in electrochemical environments. In this work, we report a new approach to flexible energy devices. We suggest the use of a flexible electrode based on free-standing graphene paper, to be applied in lithium rechargeable batteries. This is the first report in which graphene paper is adopted as a key element applied in a flexible lithium rechargeable battery. Moreover graphene paper is a functional material, which does not only act as a conducting agent, but also as a current collector. The unique combination of its outstanding properties such as high mechanical strength, large surface area, and superior electrical conductivity make graphene paper, a promising base material for flexible energy storage devices. In essence, we discover that the graphene based flexible electrode exhibits significantly improved performances in electrochemical properties, such as in energy density and power density. Moreover graphene paper has better life cycle compared to non-flexible conventional electrode architecture. Accordingly, we believe that our findings will contribute to the full realization of flexible lithium rechargeable batteries used in bendable electronic equipments.
xLiH+M composites, where M=Mg or Ti, are suggested as new candidates for negative electrode for Li-ion batteries. For this purpose, the xLiH+M electrode is prepared using the mechanochemical reaction: MH x + xLi→ xLiH+M or by simply grinding a xLiH+M mixture. The most promising electrochemical behaviour is obtained with the (2LiH+Mg) composite prepared via a mechanochemical reaction between MgH2 and metallic Li leading to a very divided composite in which Mg crystallites of 20nm size are embedded in a LiH matrix. Reversible capacities of 1064mAhg−1 (three times as much as the one of graphite) and 600mAhg−1 are reached for these phase mixtures after 1 and 28h of grinding in vertical and planetary mill, respectively. The (2LiH+Ti) mixture prepared via the mechanochemical reaction between TiH2 and Li exhibits a reversible capacity of 428mAhg−1. From X-ray diffraction measurements, the performances of the electrodes are attributed to the electrochemical conversion reaction: M+ xLiH↔MH x + xLi+ + xe− (M=Mg, Ti) followed for M=Mg by an alloying process where M reacts with lithium ions to form Mg1−x Li x alloys.
For application to Li-ion batteries, we studied the electrochemical behavior and thermal stability of the following two combinations of binary electrolyte additives in a triphenylphosphate (TPP)-containing ionic electrolyte: vinyl acetate (VA) plus vinylene carbonate (VC), and vinyl ethylene carbonate (VEC) plus biphenyl (BP). Mesocarbon microbeads (MCMB) and LiCoO2 were used as the anode and cathode materials, respectively. Cyclic voltammetry (CV), differential scanning calorimetry (DSC), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) were used for the analyses. These results confirmed the capability of the VEC+BP electrolyte additive to improve the cell performance and electrolyte thermal stability in TPP-containing solutions in Li-ion batteries.
The effects of a small amount of fluoroethylene carbonate (C3H3FO3 or FEC) on the electrochemical performance of lithium-rich layered oxide cathode Li1.16[Mn0.75Ni0.25]0.84O2 have been focused herein. When 1 vol.% or 2 vol.% FEC was introduced into the electrolyte, cycling performance and rate capability of Li1.16[Mn0.75Ni0.25]0.84O2 have been improved, and the initial irreversible capacity (Cirr) loss has been lessened by suppressing the parasitic side reactions between cathode and electrolyte. However, excess FEC (5% in volume) will lead to the decreased lithium transference number (tLi+), large concentration polarization and the reduced discharge capacity especially at high current. DFT calculations indicate that FEC enhances the anti-oxidation ability of the electrolyte system, and the preferential accumulation and reaction of FEC near cathode during charging due to the strong coordination between FEC and PF6 − anion. The results from electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS) and differential scanning calorimetry (DSC) measures indicate that a more stable SEI film has been formed on the cathode surface with FEC as additive, which leads to the suppression of the electrolyte aggressive decomposition and the enhancement of thermal stability.
The use of nonhalogenated electrolyte salts for electrochemical devices is very important from the point of view of safety and cost. We have investigated the physical and electrochemical properties of a series of quaternary ammonium bis(oxalato)borates (QABOBs) and the performance of electric double-layer capacitors (EDLCs). The mass and van der Waals volume of BOB− are higher and larger than those of BF4 −. The mass densities, viscosities, and surface tensions of propylene carbonate (PC) solutions containing the QABOBs are higher than those obtained for tetraethylammonium tetrafluoroborate (TEABF4), and the electric conductivities become lower. However, the electrochemical voltage windows measured with an activated carbon electrode and the gravimetric capacitances of 2025-type coin cells are comparable to those obtained for the PC solutions containing the TEABF4.
The low viscosities of the linear sulfites dimethyl sulfite and diethyl sulfite are suggesting an investigation of their suitability as low viscosity co-solvents for ethylene carbonate based electrolytes. In this study, electrochemical performances at graphitic anodes and conductivities in the temperature range −60 to +60°C are presented. Comparisons with the linear carbonates dimethyl carbonate and diethyl carbonate, which have been currently used as low viscosity solvents in lithium ion batteries, are made.
High voltage LiNi0.5Mn1.5O4 (LNMO) spinel with an operating voltage of 4.7V is a promising candidate as the positive electrode in future lithium ion batteries for electric vehicle applications. However, LNMO displays a capacity fading problem in LNMO/graphite full-cells. Understanding the capacity fading mechanism of LNMO is important for implementing it in next-generation lithium ion batteries. Performance comparisons between LNMO/Li half-cell cycled and LNMO/graphite full-cell cycled were carried out. Whereas no degradation was observed for half-cells, full-cell usable capacity decreased by >50% after 100 cycles. The performance of LNMO and graphite electrodes that experienced full-cell cycling for >100 cycles were then evaluated in fresh half-cells. Results indicated that there is no degradation of the individual LNMO and graphite electrodes. The voltage profiles and dQ/dV curves of full-cells were compared with those of simulated profiles based on half-cell data. Experimental data were successfully reproduced by simulation based on an assumption that the capacity fading in full-cells was originated from the Li+ loss in LNMO. The amount of Mn deposited on Li-metal in the LNMO/Li half-cells was determined to be ∼0.3% of the total Mn weight in the LNMO electrode after 200 cycles at 30°C. The capacity fading of the LNMO/graphite can be explained by the impact of Mn dissolution, and active Li+ loss in the full-cell system through continuous SEI formation (electrolyte reduction) prompted by Mn reduced on top of graphite surface.
Plant–plant interactions are largely influenced by both environmental stress and ontogeny. Despite the effects of each of these factors on the overall outcome of these interactions has received considerable attention during the last years, the joint effects of both factors as drivers of such outcome are poorly understood. We used the combination of spatial pattern analysis, fruit production surveys, carbohydrate assays, sowing experiments and dendrochronological techniques to explore the interaction between Stipa tenacissima (nurse) and Lepidium subulatum (protégée) in two different slope aspects. This battery of techniques allows us to study the effects of the nurse plant during the whole life cycle of the protégée, and to assess the role of spatio-temporal variability in abiotic stress as a modulator of ontogenetic shifts in plant–plant interactions. Spatial pattern analyses suggested a net facilitative effect of S. tenacissima on L. subulatum. This effect was particularly important during the germination, shifting to competition (growth reduction) early after establishment. Competition was gradually reduced as the shrub aged, suggesting niche differentiation. The magnitude of competition was reduced under low rainfall levels in south-facing slopes, whereas this response was observed due to other abiotic factors in north-facing slopes. Our results highlight the crucial effect that positive interactions at early life-stages have to determine the long-term outcome of a given plant–plant interaction, and the existence of multiple shifts between facilitation and competition along different life-stages of the protégée. They also show how these ontogenetic shifts are modulated by abiotic factors, which differ among slope aspects. These findings may help to refine conceptual and theoretical models about shifts between facilitation and ontogeny under current climate change scenarios.
Electrochemical and electrical double layer characteristics for the phase boundary nanoporous carbon |1.0M triethylmethylammonium tetrafluoroborate (TEMA) solution in acetonitrile (AN), γ-butyrolactone (GBL), acetone (DMK) and propylene carbonate (PC) have been studied using the cyclic voltammetry (CV) and the electrochemical impedance spectroscopy (EIS) methods. The constant current and constant power charge/discharge characteristics of capacitor modules constructed and filled with different electrolytes were tested over the temperature range from −30 to +60°C. Tests for “lifetime” of the capacitors were performed at elevated temperature. Energy density versus power density, i.e. so-called Ragone plots were constructed to characterize the performance of the capacitor modules. It was established that the energy density, power density, discharge time, etc. of the electrical double layer capacitors (EDLC) depend on the pore size distribution and conductivity of the nanoporous electrode material. It was shown that the energy output of capacitor depends on the viscosity and molar conductivity of a solvent. The power output of the capacitor increased in the order of solvent PC<DMK<GBL<AN in agreement with the dependence of the Ragone plot parameters on temperature.
A new approach of Thermal Impedance Spectroscopy (TIS) is introduced for thermal characterization of battery cells. It examines the transfer behavior between internal heat generation and resulting battery surface temperature in the frequency domain. Compared to previously published TIS methods the internal heat generation forced by electrical operation can be determined without any previous knowledge or assumptions on the electric/electrochemical behavior of the battery cell. The complete procedure is demonstrated by the TIS-application on a cylindrical High-Power Li-Ion cell. By the use of a thermal battery model, its theoretical transfer function can be fitted to the TIS-measurement results in the Nyquist-Plot. Consequently, the specific heat capacity and the heat conductivity of the cell's jelly roll can be derived. A comparison of the exemplary operated TIS to conventional thermal characterization methods shows a difference of 5% in the heat capacity and 12% in the heat conductivity determination. Future improvements on the experimental setup are suggested in order to reach a higher measurement accuracy and additionally, the systematic advantages of the easy to operate and non-destructive TIS-method are presented.
Middle cerebral artery occlusion (MCAo) in mice results in a brain infarct, the volume of which depends on the length of occlusion. Following permanent occlusion, neuropathological changes – including a robust glial inflammatory response – also occur downstream of the infarct in the spinal cord.
PVD method was shown advantageous for producing Nb2O5 thin film on the 316L SS.316L SS coated with Nb2O5 film to be used in biomedical devices.Nb2O5 coating improved biological response of the 316L SS.Nb2O5 thin film are less toxic and induces less inflammation in gingival cells.
Iron fluoride based conversion cathode materials, LiF/Fe/V2O5 nanocomposites with high activity and good cyclic stability have been prepared in the discharged state by employing high energy ball milling and characterized by using XRD, SEM and TEM techniques. Li cycling behavior have been investigated by using galvanostatic cycling and cyclic voltammetry. It has been inferred that addition of V2O5 significantly enhanced the performance of the LiF/Fe nanocomposites by improving its electronic as well as its ionic conductivity. LiF/Fe/V2O5 (15 wt.%, 30 h ball milled) shows the best cycling performance. A high first cycle discharge capacity of ∼510 (±5) mA h g−1 is observed. At the end of 50th cycle, the capacity observed is ∼270 (±5) mA h g−1. The heat treated LiF/Fe/V2O5 (15 wt.%, 20 h ball milled) nanocomposite shows a notable improvement in cycling stability than the as prepared nanocomposite and a reversible capacity of ∼310 (±5) mA h g−1 is observed at the end of 50 cycles. The average charge–discharge potentials observed in CV are ∼2.9 and ∼1.7 V, respectively. Ex-situ XRD, TEM and EIS measurements are performed on cycled electrodes of LiF/Fe/V2O5 (15 wt.%; 30 h ball milled) at selected voltages to understand the reaction mechanism.
There is a growing need to reliably measure absorbed dose in low temperature samples, especially in the pharmaceutical and tissue banking industries. All dosimetry systems commonly used in the irradiation industry are temperature sensitive. Radiation of low temperature samples, such as those packaged with dry ice, must therefore take these dosimeter temperature effects into consideration. This paper will suggest a method to accurately deliver an absorbed radiation dose using dosimetry techniques designed to abrogate the skewing effects of low temperature environments on existing dosimetry systems.
The genome of the Antarctic bacterium Pseudomonas extremaustralis was analyzed searching for genes involved in environmental adaptability focusing on anaerobic metabolism, osmoregulation, cold adaptation, exopolysaccharide production and degradation of complex compounds. Experimental evidences demonstrated the functionality of several of these pathways, including arginine and pyruvate fermentation, alginate production and growth under cold conditions. Phylogenetic analysis along with genomic island prediction allowed the detection of genes with probable foreign origin such as those coding for acetate kinase, osmotic resistance and colanic acid biosynthesis. These findings suggest that in P. extremaustralis the horizontal transfer events and/or gene redundancy could play a key role in the survival under unfavorable conditions. Comparative genome analysis of these traits in other representative Pseudomonas species highlighted several similarities and differences with this extremophile bacterium.
To improve the electrochemical performance of lithium sulfur batteries, a conductive Lewis base matrix, nitrogen doped graphene (NG), was prepared here through a facile strategy of annealing a polypyrrole/reduced graphene oxide composite. The obtained NG was demonstrated with enriched pyridinic-N doping and was employed as the matrix of sulfur cathode with ultra-high rates, reversible capacity and high coulombic efficiency. The improved performance can be attributed to the high conductivity of the NG and the enhanced adsorption energy of Li2Sn (n=4-8) on the NG surface. The NG can act not only as an electronic conductive network but also as a Lewis base “catalyst” matrix that promotes the higher Li2Sn to be further oxidized completely to S8 as demonstrated in the cyclic voltammetry curve, which can thus significantly improve the sulfur utilization and cyclic stability even at a high sulfur loading of 75% (w/w) in the S@NG composite.
The membrane electrode assembly (MEA) is the key component of a PEMFC stack. Conventional MEAs are composed of catalyzed electrodes loaded with 0.1–0.4mgPt cm−2 pressed against a Nafion® membrane, leading to cell performance close to 0.8Wcm−2 at 0.6V. Due to their limited stability at high temperatures, the cost of platinum catalysts and that of proton exchange membranes, the recycling problems and material availability, the MEA components do not match the requirements for large scale development of PEMCFs at a low cost, particularly for automotive applications. Novel approaches to medium and high temperature membranes are described in this work, and a composite polybenzimidazole–poly(vinylphosphonic) acid membrane, stable up to 190°C, led to a power density of 0.5Wcm−2 at 160°C under 3bar abs with hydrogen and air. Concerning the preparation of efficient electrocatalysts supported on a Vulcan XC72 carbon powder, the Bönnemann colloidal method and above all plasma sputtering allowed preparing bimetallic platinum-based electrocatalysts with a low Pt loading. In the case of plasma deposition of Pt nanoclusters, Pt loadings as low as 10μgcm−2 were achieved, leading to a very high mass power density of ca. 20 kW g Pt − 1 . Finally characterization of the MEA electrical properties by Electrochemical Impedance Spectroscopy (EIS) based on a theoretical model of mass and charge transport inside the active and gas diffusion layers, together with the optimization of the operating parameters (cell temperature, humidity, flow rate and pressure) allowed obtaining electrical performance greater than 1.2Wcm−2 using an homemade MEA with a rather low Pt loading.
Model-based observers appeal to both research and industry utilization due to the high accuracy and robustness. To further improve the robustness to dynamic work conditions and battery ageing, the online model identification is integrated to the state estimation, giving rise to the co-estimation methods. This paper systematically compares three types of co-estimation methods for the online state of charge of lithium-ion battery. This first method is dual extended Kalman filter which uses two parallel filters for co-estimation. The second method is a typical data-model fusion method which uses recursive least squares for model identification and extended Kalman filter for state estimation. Meanwhile, a noise compensating method based on recursive total least squares and Rayleigh quotient minimization is exploited for online model identification, which is further designed in conjunction with the extended Kalman filter to estimate the state of charge. Simulation and experimental studies are carried out to compare the performances of three methods in terms of the accuracy, convergence property, and noise immunity. The computing cost and tuning effort are further discussed to give insights to the application prospective of different methods.
Sodium polyanionic materials provide various structural frameworks compared to their lithium counterparts, leading to diverse studies on novel polyanion-based electrode materials for sodium ion batteries. Na4M3(PO4)2P2O7 (M = Mn, Fe, Co, Ni, and Mg) is a new class of mixed-anion phosphates combined with two polyanion groups, (PO4)3− and (P2O7)4−. It is an attractive electrode candidate because of its stable cyclability and low volume changes upon cycling. Although Mn-based mixed-anion phosphate materials have shown a high redox potential of 3.8 V vs. Na+/Na, they have suffered from low electrical conductivity and structural distortion upon oxidation. Partial substitution of Mn by other divalent cations is an efficient strategy to suppress lattice distortion and to affect the phase transition process during electrochemical cycling. Here we study the cation substitution effect of the Mn-based mixed-anion phosphates on the phase stability and the kinetics of the electrochemical reaction. The electrochemical reversibility was found to be improved by certain cation substitution. In particular, Co substitution not only increased the operating voltage but also enhanced both cyclability and rate capability. Furthermore, we investigate the phase changes upon cycling using in situ synchrotron X-ray diffraction, supporting the positive effect of the mixed-anion phosphate structure through cation substitution.