batterydata/paper-abstracts huggingface dataset:
Liquid crystalline is a state of matter which combines the properties of liquid and a crystalline solid. Ionic liquid crystals are a new class of materials which exhibit phase transition at low temperature. A new structure was synthesized based on a benzene ring carrying three armed, two arms of triazine ring and the third arm is phenoxy benzene. The presence of alkyl chain groups on the periphery reduced the mesophase transitions which are desirable for low-temperature applications of liquid crystals. The substitution was achieved efficiently by Sonogashira coupling. The tri-armed compound was synthesized successfully through cross-coupling. However, it was oily and no transition phase was observed. Therefore, to increase the liquid crystal possibility, the compound was mixed with 4-(dodecyloxy)benzoic acid (4-DBA) with 1:1 ratio to produce an organic salt through hydrogen bonding. The organic salt obtained by ionic interaction between the tri-armed compound and 4-DBA exhibited a phase transition at low temperature. However, ionic liquid crystals are important class of mesomorphic materials and have considered as sealants due to their very low vapour pressure which demonstrated a proficient electrolyte systems for their anisotropic phase such as high ionic conductivity and diffusion along with excellent thermal stability. All the intermediate compounds and final compounds were confirmed by spectroscopic techniques (1H NMR, 13C NMR, FT-IR, and HRMS).
Mathematical modelling is an essential tool for the design of solid oxide fuel cells (SOFCs). The present paper aims to report on the development of a dynamic anode-supported intermediate temperature direct internal reforming planar solid oxide fuel cell stack model, that allows for both co-flow and counter-flow operation. The developed model consists of mass and energy balances, and an electrochemical model that relates the fuel and air gas composition and temperature to voltage, current density, and other relevant fuel cell variables. The electrochemical performance of the cell is analysed for several temperatures and fuel utilisations, by means of the voltage and power density versus current density curves. The steady-state performance of the cell and the impact of changes in fuel and air inlet temperatures, fuel utilisation, average current density, and flow configuration are studied. For a co-flow SOFC operating on a 10% pre-reformed methane fuel mixture with 75% fuel utilisation, inlet fuel and air temperatures of 1023K, average current density of 0.5Acm−2, and an air ratio of 8.5, an output voltage of 0.66V with a power density of 0.33Wcm−2 and a fuel efficiency of 47%, are predicted. It was found that cathode activation overpotentials represent the major source of voltage loss, followed by anode activation overpotentials and ohmic losses. For the same operating conditions, SOFC operation under counter-flow of the fuel and air gas streams has been shown to lead to steep temperature gradients and uneven current density distributions.
Lithium-Ion (liquid electrolyte) batteries are considered as long life and reliable systems. This paper: • introduces discussion about aging and degradation mechanism both for storage and cycling, • illustrates the proposed phenomena from results based on several years experimentation and obtained on scale one cells, • shows the behaviour of several kinds of active materials, • proposes some trends for life prediction. Aging in Li-Ion cells may mainly come from: • reactions of active materials with electrolyte at electrodes interfaces, • self degradation of active materials structure on cycling, • aging of non active components (ex: electrodes binders). These phenomena lead to energy and/or power losses. Reaction rates on depending on: • type of materials and reactivity • impurities • manufacturing processes • cell design • type of application and profile of use. On the negative electrode side the main parameters are passivation layer stability, the layer structure/composition (effect of additives in electrolyte and formation process), polluting agents. On the positive electrode side key factors seem to be the material structure evolution and organic solvent oxidation. These phenomena are highly dependent of voltage and temperature. So far, according to experimentation for electric (EV) and hybrid (HV) vehicles applications, using scale 1 cells built with nickel based positive material the results show: • more than 1200 deep cycle (80% d.o.d. EV cycle) with only few percent of energy and power losses, • more than 500000 shallow cycles (3% d.o.d. HV cycle) with negligible power losses, • 2 years of storage testing at full charge and various temperature (20°C/40°C/60°C) leading to a life expectation of 10 years for EV applications and 15 years for HV applications.
Cr-doped Li3V2−x Cr x (PO4)3/C (x =0, 0.05, 0.1, 0.2, 0.5, 1) compounds have been prepared using sol–gel method. The Rietveld refinement results indicate that single-phase Li3V2−x Cr x (PO4)3/C with monoclinic structure can be obtained. Although the initial specific capacity decreased with Cr content at a lower current rate, both cycle performance and rate capability have excited improvement with moderate Cr-doping content in Li3V2−x Cr x (PO4)3/C. Li3V1.9Cr0.1(PO4)3/C compound presents an initial capacity of 171.4mAhg−1 and 78.6% capacity retention after 100 cycles at 0.2C rate. At 4C rate, the Li3V1.9Cr0.1(PO4)3/C can give an initial capacity of 130.2mAhg−1 and 10.8% capacity loss after 100 cycles where the Li3V2(PO4)3/C presents the initial capacity of 127.4mAhg−1 and capacity loss of 14.9%. Enhanced rate and cyclic capability may be attributed to the optimizing particle size, carbon coating quality, and structural stability during the proper amount of Cr-doping (x =0.1) in V sites.
The practical applicability of the considerations made in a previous paper to characterize energy balances in stand-alone photovoltaic systems (SAPV) is presented. Given that energy balances were characterized based on monthly estimations, the method is appropriate for sizing installations with variable monthly demands and variable monthly panel tilt (for seasonal estimations). The method presented is original in that it is the only method proposed for this type of demand. The method is based on the rational utilization of daily solar radiation distribution functions. When exact mathematical expressions are not available, approximate empirical expressions can be used. The more precise the statistical characterization of the solar radiation on the receiver module, the more precise the sizing method given that the characterization will solely depend on the distribution function of the daily global irradiation on the tilted surface H g βi . This method, like previous ones, uses the concept of loss of load probability (LLP) as a parameter to characterize system design and includes information on the standard deviation of this parameter (σ LLP) as well as two new parameters: annual number of system failures (f) and the standard deviation of annual number of system failures (σ f). This paper therefore provides an analytical method for evaluating and sizing stand-alone PV systems with variable monthly demand and panel inclination. The sizing method has also been applied in a practical manner.
This study is part of a project regarding explanatory illustrations in science education. Research questions here concern how pupils use and make meaning from illustrations in a science textbook. Electricity was chosen as the subject. Video data was collected in 8 sessions, each with a pair of pupils, 10-11 years of age in one school in Sweden. Communication within the pairs and with the interviewer was analyzed. The children also drew a picture of a battery and explained its function using this drawing. The most striking result was an almost complete lack of transparency for the scientific information in the illustrations. Regardless of previous knowledge, pupils were almost never able to collect new information on their own or together with their peer. As long as the visual information matched previous knowledge they could explain the content, but as the complexity increased, they were lost. They then either expressed their incomprehension or carried on to argue for evident misconceptions, not realizing that the illustrations were contradicting them. Together with the interviewer, pupils could eventually identify central scientific messages and where their previous understanding was challenged. One conclusion is that scientific illustrations can drive scientific in-depth discussion. However, the main conclusion is that pupils are not trained to interpret multimodal information themselves and that teachers and textbook authors therefore risk overestimating pupils de-coding abilities.
SiEnergy Systems Llc, a Harvard University spin-off company, says that it has made a breakthrough in scaling the power output of ultra-thin film, low-temperature micro-solid-oxide fuel cells.
Potential applications of attention bias modification (ABM) for acute and chronic pain patients are investigated. In study 1, 54 acute back pain patients (46 of whom completed the study) were recruited at their initial physiotherapy session and randomised to receive 1 session of ABM or placebo. Patients were followed up 3months later. Participants who were randomised to receive ABM reported less average (P =0.001) and current pain (P =0.008) and experienced pain for fewer days (P =0.01) than those who received placebo. In study 2, 34 chronic pain patients were recruited and randomly assigned to receive either 4 sessions of ABM (n =22) or placebo (n =12), followed by 8 sessions of cognitive behavioural treatment (CBT). After ABM, there was a significant group-by-time effect for disability. By 6-month follow-up, differences had emerged between the 2 training groups, such that the ABM group had shown greater reductions in anxiety sensitivity and disability than the placebo group. Although the results of these studies show that there is potential in the application of ABM to pain conditions, the mechanisms of treatment could not be established. Neither group showed an initial bias towards the word stimuli or a training effect, and only in the acute pain group were changes in biases related to outcome. Nonetheless, the fact that 2 independent samples showed a positive effect of ABM on clinical outcomes suggests that ABM is worthy of future study as an intervention for pain patients.
Potassium hydroxide (KOH) activated Super P (Ksp) was adopted to prepare Ksp/S composite by chitosan assisted chemical synthesis approach. The Ksp/S was further heat treated at 159°C and then coated by polyaniline (PANI) to fabricate Ksp/S-159 and Ksp/S-159/PANI composites, respectively. The heat treated binary sulfur/carbon and PANI coated ternary sulfur complex showed enhanced cycle performance and rate capability. However, the electrochemical behavior of Ksp/S-159 and Ksp/S-159/PANI can be greatly affected by the discharge current. The Ksp/S-159/PANI composite delivers an initial discharge capacity of 1202.3mAhg−1 and keeps 954mAhg−1 after 100cycles at 0.5mAcm−2 (0.31C). The Ksp/S-159 presented a maximum capacity up to 892.5mAhg−1 at 2macm−2 (1.26C) and retained about 409.2mAhg−1 after 500 cycles. The PANI coated ternary sulfur complex shows good electrochemical performance at low discharge current while the heat treated sulfur/carbon shows good rate capability at high discharge current. The different electrochemical behavior is fully discussed to illustrate the complex Li-S discharging process.
Demand-side management (DSM) in response to market-based electricity tariffs can potentially increase the efficiency and reliability of the electric power grid. This study introduces a novel, one-day-ahead DSM framework which optimizes temperature setpoints and battery dispatch in office buildings, subject to a time-varying and/or demand-based electricity tariff. To reflect real world implementation, our framework operates in two-steps. First, during the passive, battery-only DSM optimization, historical weather and electricity load data for a given building are used to determine its optimal battery capacity. Second, once the battery has been installed, a one-day-ahead, real-time DSM algorithm optimizes both the building’s daily temperature setpoints and the battery's charge/discharge pattern. The optimization objective is to minimize the total operating cost (tariff charges and battery system) while still satisfying occupants’ thermal comfort. Using a case study with a medium-fidelity electric load model for a standard office building, the performance of the proposed framework is validated by quantifying savings in operating cost, reduction of monthly grid peak loads, and the achieved human occupant comfort. To illustrate the advantage of optimizing temperature setpoints and battery dispatch concurrently, the combined performance is compared with that achieved by standalone DSM (i.e., using only battery dispatch or only temperature setpoints). We found that concurrent optimization can reduce a building's monthly peak demand on the grid by up to 26%. Electricity tariff charges are reduced by 11%, more than is required to offset storage costs, thus providing an overall profit to building operators who use such DSM. Payback time is approximately 5 years.
Confronted with the difficult in tuning the microstructures (components, crystalline state and particle size) of metal phosphide anodes for sodium ion batteries (SIBs), it is of great challenge and fundamentally important to develop a rational strategy to design hierarchically porous structure metal phosphide anodes for high-performance SIBs. Herein, for the first time, a unique core-shell porous FeP@CoP phosphide micocubes interconnected via reduced graphene oxide (RGO) nanosheets (RGO@CoP@FeP) are for the first time synthesized via a low-temperature phosphorization process using prussion blue as reactant template. The RGO@CoP@FeP hierarchical architecture SIBs anodes exhibit greatly improved reversible capacity, cycling stability and excellent rate capability. The enhanced electrochemical performance of RGO@CoP@FeP is ascribed to the uniquely porous core-shell microstructure and synergistic effect between the phosphide components. The core-shell structure with FeP as core and CoP as shell can provide enough cushion spaces for volume changes, as well as shorten the Na+ diffusion path. The interconnected RGO nanosheets and carbon layer wrapped on the FeP core cubes together build a conductive highway, enhancing charge transfer kinetics. The present strategy using MOFs as reactant templates for porous core-shell phosphide electrodes can be extended to other novel electrodes for high performance energy storage devices.
In this paper, we report on a rechargeable lithium battery based on a single hexagonal tungsten oxide (h-WO3) nanowire. This nanobattery can discharge at a voltage of 0.27–0.1V and a current of 20–10pA for more than 1000s with a capacity of 15.2nC, suggesting that each WO3 molecule could accommodate 1.8–2.2 Li+ ions on average. It exhibits excellent stability and repeatability. Real time ultraviolet (UV) light detection is achieved through a single WO3 nanowire based UV sensor, which is powered by the nanobattery.
The enormous demands on available global lithium resources have raised concerns about the sustainability of the supply of lithium. Sodium secondary batteries have emerged as promising alternatives to lithium batteries. We describe here sodium bis(trifluoromethylsulfonyl) amide (NaNTf2) electrolyte systems based on 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) amide (C4mpyrNTf2) ionic liquids. The electrochemical stability of the system was examined; a pair of facile cathodic and anodic processes around 0V vs. Na/Na+ were observed in cyclic voltammetry measurements and interpreted as deposition and dissolution of sodium metal. Density, viscosity and conductivity of the electrolytes were studied. It was found that the ionic conductivity of electrolytes reached as high as 8mS/cm, decreasing slowly as the salt content increased due to increasing of viscosity and density of the electrolyte. Therefore, sodium electrolytes based on C4mpyrNTf2 appear to be promising for secondary sodium battery applications.
High capacity lithium-sulfur batteries with stable cycle performance and sulfur loadings greater than 70 wt% are regarded as promising candidates for energy storage devices. However, it has been challenged to achieving practical application of sulfur cathode because of low loading of active sulfur and poor cycle performance. Herein, we design novel nanocomposite cathode materials consist of sulfur (80 wt%) embedded within nitrogen doped three-dimensional reduced graphene oxide (N-3D-rGO) by controllable sulfur-impregnation method. Nitrogen doping helps increase the surface area by ten times from pristine graphene, and pore volume by seven times. These structural features allow the cathode to hold more sulfur. It also adsorbs polysulfides and prevents their detachment from the host materials; thereby achieving stable cycle performance. The solution drop sulfur-impregnation method provides uniform distribution of nano-sulfur in controlled manner. The material delivers a high initial discharge capacity of 1042 mAhg−1 and 916 mAhg−1 with excellent capacity retention of 94.8% and 81.9% at 0.2 C and 0.5 C respectively after 100 cycles. Thus, the combination of solution drop and nitrogen doping opens a new chapter for resolving capacity fading as well as long cycling problems and creates a new strategy to increase sulfur loading in controlled mechanism.
Objective To examine the relationship between reproductive history, pregnancy complications, and later physical function. Study design The Bogalusa Heart Study is a long-running study of cardiovascular health in a semirural community. 761 women were interviewed about their pregnancy history and complications, and underwent tests of physical function. Logistic models for dichotomous outcomes and linear models for continuous outcomes were used, adjusted for covariates. Main outcome measures Overall scores on the Short Physical Performance Battery (SPPB), which combines scores for balance, gait speed, and chair stands. Additional tests were a 6-min walk, knee extension strength, grip strength, and a pegboard challenge. Results Nulliparity was associated with lower scores on the walking and balance portions of the SPPB, less distance covered in the 6-min walk, less knee and grip strength, and higher pegboard time, especially among pre-menopausal women. A history of gestational diabetes was associated with more problems on the walk portion of the SPPB (aOR 2.44, 1.06–5.65), higher chair stand time, and lower knee strength. Young age at first birth (<16 or 18 years) was associated with a shorter chair stand time and a better pegboard score. Conclusions Nulliparity was associated with worse physical functioning, while high parity and early pregnancy were not, suggesting that fertility is associated with better health later in life. Pregnancy complications were associated with worse physical functioning, even after controlling for body mass index. Future studies should attempt to establish the pathways by which reproductive health relates to overall physical functioning.
Fe2O3 nanoparticles are employed as a coating material to optimize the electrochemical performance of LiCoO2 at high voltage. When the current rate is 1C with the cutoff potential at 4.5V, the 5wt.% Fe2O3-coated LiCoO2 delivers an initial capacity of 168.7mAhg−1. More importantly, its capacity retention after 50 cycles reaches up to 92.6%, whereas the value for pristine LiCoO2 is only 58.5%. The electrochemistry impedance spectroscopy analysis demonstrates that Fe2O3 coating plays an important role in decreasing the charge transfer resistance of cell. Compared with the performance of the Fe2O3-mixed and Fe-doped LiCoO2 samples, it is found that the role of Fe2O3 coating is unique, which may change the characteristic of the surface of LiCoO2 particles. This technique may provide an effective and convenient way for optimizing other electrode materials.
The conductivity, viscosity and the self-diffusion coefficient of pyrrolidinium-based ILs (ILs), N-butyl-N-methyl pyrrolidinium-bis(trifluoromethanesulfonyl)imide (Pyr14TFSI) and N-methyl-N-propyl pyrrolidinium-bis(fluorosulfonyl)imide (Pyr13FSI), and their binary mixtures were investigated in order to better understand their behavior as electrolyte components in supercapacitor and lithium battery systems. The IL mixtures showed excellent low temperature properties far exceeding those of the pure IL materials. For example, at −40°C the conductivity of binary mixtures was found to be up to four orders of magnitude higher than that of the pure ILs.
Monoclinic Li3V2−x Al x (PO4)3 with different Al3+ doping contents (x =0, 0.05, 0.08, 0.10 and 0.12) have been prepared by a facile aluminothermal reaction. Aluminum nanoparticles have been used as source for Al3+ and nucleus for Li3V2−x Al x (PO4)3 nucleation as well as reducing agent in the aluminothermal strategy. The products were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and electrochemical methods. The XRD results show that the as-obtained Li3V2−x Al x (PO4)3 has a phase-pure monoclinic structure, irrespective of the Al3+ doping concentration. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) results reveal that the charge-transfer resistance of the Li3V2(PO4)3 is reduced and the reversibility is enhanced after V3+ substituted by Al3+. In addition, The Li3V2−x Al x (PO4)3 phases exhibit better cycling stability than the pristine Li3V2(PO4)3.
Integrated waste management systems are one of the greatest challenges for sustainable development. For these systems to be successful, the first step is to carry out waste characterization studies. In this paper are reported the results of a waste characterization study performed in the Campus Mexicali I of the Autonomous University of Baja California (UABC). The aim of this study was to set the basis for implementation of a recovery, reduction and recycling waste management program at the campus. It was found that the campus Mexicali I produces 1ton of solid wastes per day; more than 65% of these wastes are recyclable or potentially recyclable. These results showed that a program for segregation and recycling is feasible on a University Campus. The study also showed that the local market for recyclable waste, under present conditions – number of recycling companies and amounts of recyclables accepted – can absorb all of these wastes. Some alternatives for the potentially recyclables wastes are discussed. Finally some strategies that could be used to reduce waste at the source are discussed as well.
Rechargeable calcium (Ca) batteries have the prospect of high-energy and low-cost. However, the development of Ca batteries is hindered due to the lack of efficient electrolytes. Herein, we report novel calcium tetrakis(hexafluoroisopropyloxy)borate Ca[B(hfip)4]2 based electrolytes exhibiting reversible Ca deposition at room temperature, a high oxidative stability up to 4.5 V and high ionic conductivity >8 mS cm−1. This finding opens a new approach towards room-temperature rechargeable calcium batteries.