batterydata/paper-abstracts huggingface dataset:
In this study, we have investigated the effects of varying flow channel depths and addition of various channel obstructions on the electrochemical performance and pumping power requirements of vanadium redox flow batteries (VRFBs). Specifically, 3D-printed ramps and prismatic obstructions were inserted into the channels of interdigitated flow field (IDFF) and parallel flow field (PFF) designs to observe the effect of non-uniform channel depth on the mass transport properties of open- and closed-ended flow channels. Results were compared with conventional flow field geometries. Integration of ramps into the closed-ended (i.e., IDFF) flow channels resulted in 15% improvement in peak power density (PPD) at a flow rate of 50 mL min−1. Addition of ramps to IDFF has also resulted in a significant 40% drop in required pumping pressure due to guided and gradual delivery of the electrolyte to the electrode plane. In addition, the effects of varying channel depths in open-ended (i.e., PFF) channels were found to be much more drastic with improvements in PPD up to 150%. Overall, findings of this study highlight the significance of varying channel depths on improving the mass transport characteristics of VRFBs and offer an alternative approach for design of high-performance flow cells.
In this study, we report a facile process for preparing a carbon-coated nanosized Li4Ti5O12 nanoporous micro-sphere (CN-LTO-NMS) by a carbon pre-coating process combined with the spray drying method. The obtained material consists of a micron-size secondary sphere (10–20 μm) accumulated by carbon-coated nanosized primary particles (∼200 nm). The nanosized primary particles and nano-thickness carbon layer uniformly coated over the particles as well as the interconnected nanopores greatly improve its rate capability. As a consequence, the resulting sample delivers a reversible capacity of 160 mAhg−1 at 0.2 C, and shows remarkable rate capability by maintaining 79% of the capacity at 20 C (vs. 0.2 C), as well as excellent cycling stability with a capacity retention of 95% after 1000 cycles at 1 C rate (vs. 0.2 C).
Modeling, numerical simulations and cost analysis are conducted for different energy configurations used to power up a factory load in Tunisia. Three configurations are considered: diesel engine generator (DE) only; combined photo-voltaic (PV)/battery storage bank and hybrid DE/PV/battery storage bank. A nonlinear model that depends on solar irradiation and ambient temperature is used to characterize PV panels. Lead-acid batteries are used in the model to store excess energy produced by PV solar system and diesel generator. The depth of discharge (dod) parameter is used to characterize the batteries. The diesel engine, synchronous generator and excitation subsystems are also modeled. The cost of operating different configurations is investigated for three countries: Tunisia, Jordan and Kingdom of Saudi Arabia (KSA); where diesel prices are heavily subsidized. Different countries are chosen to clarify the driver to use renewable energy for power generation in these countries. The drives could be for saving operating costs, for saving the environment, or for saving both. It is found that the best solution for power generation in KSA is DE. However, the hybrid PV/DE/battery bank solution is the best solution in Tunisia and Jordan. The hybrid system requires about 9 years for balancing the total cost of operation compared to the DE solution only.
Different charge storage mechanisms in electrochemical energy storage devices are reviewed, including non-Faradaic capacitive, Faradaic capacitive, Faradaic non-capacitive, and their combinations. Specifically, Faradaic capacitive (pseudocapacitive) storage and Faradaic non-capacitive (Nernstian) storage are attributed to the transfer of delocalised and localised valence electrons, respectively. Mathematical and graphical expressions of the respective storage performances are presented. The account is made especially for asymmetrical electrochemical capacitors (AECs), supercapattery and supercabattery. Both hypothetical and experimental examples are presented to demonstrate the merits of supercapattery that combines capacitive and Nernstian electrodes. Enhanced storage performance is shown by properly pairing and balancing the properties of the negatrode (negative electrode) and positrode (positive electrode) in the AEC or supercapattery. In addition, the design, laboratory manufacturing and performance of several stacks of bipolarly connected AEC cells are assessed in terms of commercial feasibility and promise.
Certain behavioral expressions of sensory modulation disorder (SMD) such as distractibility, hyperactivity, and impulsivity are often similar to those of attention deficit/hyperactivity disorder (ADHD) in pediatric and adult populations. There is also a high comorbidity rate between these two diagnoses and absence of research regarding the objective neuropsychological differentiation between them. In the present study we employed a factorial design which enabled us to: (a) systematically examine the effects of SMD and ADHD on executive attention in a sample of adult females using a Stroop-like task, and (b) measure the effect of aversive conditions (sounds) on executive attention. The experimental measures used were the Stroop-like Location – Direction Task (SLDT) to assess executive attention and the battery of aversiveness to sounds (BAS), a standardized measure of aversive sounds that was developed for this study and enabled individual customization of aversive auditory sounds. Results revealed, as expected, a specific core deficit in executive attention for the ADHD factor. In addition to that, the present study provides an important, pioneering finding of SMD impairment in a unique combination of a cognitively demanding task with aversive sounds, providing preliminary objective evidence differentiating SMD from ADHD.
Lead tin fluorides are well known fast ion conductors. In this study the electrochemical behaviour of materials as negative electrodes in lithium rechargeable batteries was investigated. The initial reduction with lithium occurs at much higher potentials for fluorides than oxides. This correlates well with the standard energies of formation of metals and lithium oxide/fluoride on lithium insertion. Lead rich compounds present a greater degree of crystallinity than tin rich materials and it is also observed that fluoride matrices exhibit greater crystallinity after cycling than their oxide counterparts. Tin oxide exhibits the best cycling performance and this seems to correlate with the low degree of crystallinity observed in this system.
Limited understanding of the high ionic conductivity of solid electrolytes is one of the major hurdles preventing the development of all-solid-state batteries for future electric vehicles. This is particularly observed in recently discovered sulfide-based solid electrolytes such as Li10GeP2S12 and Li9.54Si1.74P1.44S11.7Cl0.3, which exhibit unprecedented ionic conductivity close to or even higher than that of their liquid electrolyte counterparts. Despite recently reported experiments and simulations on their topological structures and associated ionic conductivity, the mechanisms underlying the superionic transport rate observed for these solid electrolytes are still poorly understood. Herein, we report the first results of the effect of applied electric potential on the changes in the electronic structures associated with the addition of dopant materials to solid electrolytes. Atomic simulations confirm that both Si and Cl dopants promote the polarization of Si- and Cl-bearing ionic clusters of solid electrolytes. This renders the ionic clusters mechanically less stable and thus opens up the diffusion pathway for Li+ under the presence of an electric field, facilitating the fast transport of Li+. The present work offers some design criteria that can be used to develop high-rate performance solid electrolytes.
We fabricated a high rate capability supercapacitor based on fluorine-doped graphene-carbon nanotubes aerogel network (G-CNT-F). Based on the electrochemical impedance spectroscopy data, the fluorination decreases the charge transfer resistance of graphene sheets, while CNTs act as spacer in the 3D structure. Therefore, both treatments improved the electrochemical properties of the resulted aerogel. Based on the Fourier transform infrared spectroscopy and XPS results, these excellent performances are attributed to semi-ionic bonds between fluorine and carbon. The specific capacitance of the graphene aerogel showed 78% decrease, when discharge current increases from 2 to 40 mA, while the G-CNT and G-CNT-F electrode loses 63.8 and 33.3% of its specific capacitance, respectively. The fabricated symmetric supercapacitor based on G-CNT-F shows energy density as high as 9.9 Wh/kg at the power density of 6000 W/kg in aqueous electrolytes.
This article provides a review of hazardous medical waste production and its management in Croatia. Even though Croatian regulations define all steps in the waste management chain, implementation of those steps is one of the country’s greatest issues. Improper practice is evident from the point of waste production to final disposal. The biggest producers of hazardous medical waste are hospitals that do not implement existing legislation, due to the lack of education and funds. Information on quantities, type and flow of medical waste are inadequate, as is sanitary control. We propose an integrated approach to medical waste management based on a hierarchical structure from the point of generation to its disposal. Priority is given to the reduction of the amounts and potential for harm. Where this is not possible, management includes reduction by sorting and separating, pretreatment on site, safe transportation, final treatment and sanitary disposal. Preferred methods should be the least harmful for human health and the environment. Integrated medical waste management could greatly reduce quantities and consequently financial strains. Landfilling is the predominant route of disposal in Croatia, although the authors believe that incineration is the most appropriate method. In a country such as Croatia, a number of small incinerators would be the most economical solution.
Electrochemical quartz crystal microbalance (EQCM) measurements were made during the n-doping of PEDOT films exposed to a range of electrolytes (TEABF4, TPABF4 and TEATos) in CH3CN solvent. The films were acoustically thin (“rigid”), so that the EQCM response could be interpreted gravimetrically. Correlation of the current with the time differential of the mass response allowed the determination of dopant ion and solvent fluxes as functions of applied potential during cyclic voltammetric experiments. This interpretation required the use of Faraday's law, the electroneutrality condition and the assumption (supported by variation of co-ion) that the film is permselective. The ion and solvent fluxes are in opposing directions for TEA+ insertion, but in the same direction for TPA+ insertion. As a result, the net mass change is much smaller in TEABF4 electrolyte. In both the doping or undoping half-cycles, the ion and solvent fluxes normalise with potential scan rate, indicating that they are not subject to kinetic or transport limitations on the moderate time scale of the experiment. However, there is considerable hysteresis between the responses in the two scan directions, indicating the presence of slow polymer-based processes. When the potential limits are extended to encompass p- and n-doping regimes sequentially, additional response components on the rising edges of the two doping processes signal the participation of “trapping” phenomena. The amounts of trapped dopant charge are independent of potential scan rate for both p- and n-doping. The fraction of injected charge that is trapped is larger by an order of magnitude for cation, but the absolute amounts of trapped ion are similar for cation and anion.
Reduced cycle life is one of the issues hindering the adoption of large lithium-ion battery systems in cold-climate countries. Thus, the aging mechanisms of commercial graphite/LiFePO4 (lithium iron phosphate) cells at low temperatures (room temperature, 0 °C and−18 °C) are investigated here through an extended post-mortem analysis. The cylindrical 2.3 Ah cells were cycled with a simulated battery electric vehicle load profile, and the aged cells were then disassembled inside an argon-filled glove box. A non-cycled cell was also dismantled as a reference. Half-cell testing was utilized to evaluate the degradation of the electrochemical performance of the electrodes, whereas X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, inductively coupled plasma optical emission spectroscopy and Raman spectroscopy were used to characterize the changes in the materials properties. The full-cell performance loss was mostly seen as capacity fade whereas significant changes in the cell impedance were not observed. Depending on the cycling temperature, loss of cyclable lithium due to solid electrolyte interphase growth and/or lithium plating on the graphite electrode were observed, and they are attributed as the main mechanisms responsible for the capacity loss. Furthermore, increased disordering of the graphite electrode was observed for the cell cycled at −18 °C. The graphite disordering was hypothesized to result from diffusion-induced stress and the mechanical stress caused by severe lithium plating. In contrast, the LiFePO4 electrodes showed only minimal signs of degradation regardless of the cycling temperature.
Binder is critical component to maintain the cathode integrity in lithium-sulfur battery, but it is generally non-conductive. Here sulfuric acid doped polyaniline was successfully developed as conductive binder, which showed multifunctionality when used in Li-S battery cathode, i.e., in addition to necessary adhesion function, it could trap polysulfide species to abate shuttling affect while provide good electrical conductivity. The unique adhesive behavior of conductive polyaniline was attributed to the sufficiently long polar chains consisting of amine salt, iminium and aromatic ring. Based on theoretical analysis, all the electrode components could be bound together by Van der Waals and electrostatic interactions even under very low polyaniline loading. Such low loading could form conductive polyaniline cobweb which helped the polyaniline binder to resist sulfur swelling while provide adequate channels for ion transportation. In an optimal condition, the polyaniline binder loading in cathode could be reduced to Ca. 2.0wt%, and the sulfur loading in cathode increased by 11.0wt% compared with that using common non-conductive binder. Compared with cathode employing common PVDF binder, the specific capacity using polyaniline binder increased by Ca. 104% and 74% at current density of 122mAg−1 -sulfur and 610mAg−1 -sulfur, respectively, which was mainly attributed to the stable conducting feature of polyaniline binder during the charging-discharging process, as reflected from low charge transfer resistance of 37ohm for the cathode.
Background Children with impaired motor coordination (or DCD) have difficulty using motor imagery. We have suggested that this difficulty is explained by the internal modeling deficit (IMD) hypothesis of DCD. Our previous training study lent support for this hypothesis by showing that a computerized imagery training protocol (involving action observation, and mental- and overt-rehearsal) was equally effective to perceptual-motor therapy (PMT) in promoting motor skill acquisition. Aims The study presented here was designed to replicate and extend this finding, targeting a select group of children with moderate-to-severe DCD. Methods and Procedures All 36 children with DCD who participated were referred to the study and scored below the 10th percentile for their age on the Movement Assessment Battery for Children (MABC). Using a randomized control trial, the referred children were assigned randomly to one of three groups using a blocked procedure: imagery training, perceptual-motor training (PMT), and wait-list control. Motor proficiency was measured using the MABC, pre and post-training. Individual training consisted of 60-min sessions, conducted once a week for 5 weeks. Results Results showed that the imagery protocol was equally effective as PMT in promoting motor skill acquisition, with moderate-to-large effect sizes. Individual differences showed that the majority of children in the two intervention groups improved their motor performance significantly. Conclusions Overall, these results further support the use of motor imagery protocols in the treatment of DCD, and tentative support for the IMD hypothesis. Developmental and dose issues in the implementation of imagery-based intervention are discussed.
Lithium (Li) metal is one of the most promising anode for rechargeable batteries. However, Li dendrite growth during plating/stripping process leads to many subsequent damages, such as low Coulombic efficiency, large volume change and short circuit, which can inhibit its practical application. To suppress Li dendrite, great efforts have been focused on the current collector of Li metal battery. Herein, a facile method utilizing diffusion couples Cu-X and kirkendall effect is developed to obtain 3D porous Cu current collector for Li metal anodes. The 3D current collector has interconnected pores throughout the Cu foil, which can reduce current density, provide “cages” for dendrite and enhance structural stability. As a result, Li dendrite growth is largely suppressed, giving rise to the improvement in electrochemical performances: high Coulombic efficiency even after 200 cycles, long life span of more than 2000 h, good cycling performance in full cells, etc. Moreover, the diffusion method overcome the energy/time-comsuming disadvantages of other methods for preparing porous current collectors, so it can be generalized to other synthesis of porous metal foils as a easy, sustainable and universal method. The 3D porous current collector will promote the commercialization of high-energy Li metal batteries.
Polymer-clay nanocomposites constitute a new class of materials in which the polymer matrix is reinforced by uniformly dispersed inorganic particles (usually 10wt.% or less) having at least one dimension in the nanometer scale. Nanocomposites exhibit improved properties when compared to pure polymer or conventional composites, such as enhanced mechanical and thermal properties, reduced gas permeability, and improved chemical stability. In this work, the synthesis of poly(methyl methacrylate) (PMMA)/clay nanocomposites is described via two methods: in situ and emulsion polymerization. The in situ technique follows a two-step process: ion-exchange of the clay to make it hydrophobic, and polymerization after dispersing the functionalized clay in the monomer. The emulsion technique combines the two steps of the in situ method into one by conducting ion-exchange and polymerization in an aqueous medium in the same reactor. The clay (montmorillonite, MMT) is functionalized with a zwitterionic surfactant, octadecyl-dimethyl betaine (C18DMB). Partially exfoliated nanocomposite, observed by transmission electron microscopy (TEM), was obtained by emulsion polymerization with 10wt.% clay. Glass transition temperature (T g) of this nanocomposite was 18°C higher than pure PMMA. With the same clay content, in situ polymerization produced intercalated nanocomposite with T g 10°C lower than the emulsion nanocomposite. The storage modulus of partially exfoliated nanocomposite was superior to the intercalated structure and to the pure polymer. Using nanocomposite technology, novel PMMA nanocomposite gel electrolytes were synthesized exhibiting improved ionic conductivity and stable lithium interfacial resistance. Nanocomposites can also be used for gas storage and packaging applications as demonstrated by high barrier polymer-clay films.
BACKGROUND Models of power delivery within an intact organism have been limited to ionizing radiation and, to some extent, sound and magnetic waves for diagnostic purposes. Traditional electrical power delivery within the intact human body relies on implanted batteries that limit the amount and duration of delivered power. The efficiency of current battery technology limits the substantial demands required, such as continuous operation of an implantable artificial heart pump within a human body. METHODS The fully implantable, miniaturized, Free-range Resonant Electrical Energy Delivery (FREE-D) system, compatible with any type of ventricular assist device (VAD), has been tested in a swine model (HVAD) for up to 3 hours. Key features of the system, the use of high-quality factor (Q) resonators together with an automatic tuning scheme, were tested over an extended operating range. Temperature changes of implanted components were measured to address safety and regulatory concerns of the FREE-D system in terms of specific absorption rate (SAR). RESULTS Dynamic power delivery using the adaptive tuning technique kept the system operating at maximum efficiency, dramatically increasing the wireless power transfer within a 1-meter diameter. Temperature rise in the FREE-D system never exceeded the maximum allowable temperature deviation of 2°C (but remained below body temperature) for an implanted device within the trunk of the body at 10 cm (25% efficiency) and 50 cm (20% efficiency), with no failure episodes. CONCLUSIONS The large operating range of FREE-D system extends the use of VAD for nearly all patients without being affected by the depth of the implanted pump. Our in-vivo results with the FREE-D system may offer a new perspective on quality of life for patients supported by implanted device.
Inadequate environmental sanitation in many cities is a major cause of diseases and is a drain on the economy by way of lost workdays, cost of treatment and cleanup activities. Municipal authorities and policymakers need to act fast to address this issue. Sustainable waste management provides a comprehensive inter-disciplinary framework for addressing the problems of managing urban solid waste, in the resource constrained developing countries where quality of such services are poor and costs are high often with no effective means of recovering them. Upgrading the coverage of waste management and services and increasing their efficiency is a precondition for improving the environmental quality of cities. This paper highlights the fact that the involvement and participation of all the stakeholders such as the waste generators, waste processors, formal and informal agencies, non-governmental organisations and financing institutions is a key factor for the sustainable waste management.
We report a Li-ion battery that can be charged within few minutes, passes the safety tests, and has a very long shelf life. The active materials are nanoparticles of LiFePO4 (LFP) and Li4Ti5O12 (LTO) for the positive and negative electrodes, respectively. The LiFePO4 particles are covered with 2wt.% carbon to optimize the electrical conductivity, but not the Li4Ti5O12 particles. The electrolyte is the usual carbonate solvent. The binder is a water-soluble elastomer. The “18650” battery prepared under such conditions delivers a capacity of 800mAh. It retains full capacity after 20,000 cycles performed at charge rate 10C (6min), discharge rate 5C (12min), and retains 95% capacity after 30,000 cycles at charge rate 15C (4mn) and discharge rate 5C both at 100% DOD and 100% SOC.