batterydata/paper-abstracts huggingface dataset:
The intermediate product VPO4/C is synthesized via sol-gel method, then it is mixed with other raw materials and calcined to prepare Li1-xKxVPO4F/C (x = 0, 0.005, 0.01, 0.02). Potassium with large ionic radius partially substitutes the lithium site and slightly increases the unit cell volume. The potassium dopant suppresses the formation of Li3V2(PO4)3 and reduces the particle agglomeration. The doped samples possess lower polarization and higher discharge plateau than the pristine LiVPO4F/C, and Li0.99K0.01VPO4F/C exhibits the best electrochemical performance. With 2.9 wt% amorphous carbon uniformly wrapping the surface, Li0.99K0.01VPO4F/C delivers a reversible capacity of 140.9 mA h g-1 at 0.12 C and maintains 98.3 mA h g-1 at the charge/discharge rate of 10 C. Its specific discharge capacity with a retention of 96.13% decreases from 131.9 to 126.8 mA h g-1 after 125 cycles at the charge/discharge rate of 1 C. The improvement of rate and cycling performance is ascribed to the decrease of charge transfer resistance (88.47 Ω) and the increase of Li+ diffusion coefficient (6.75 × 10−13 cm2 s−1), indicating that potassium doping facilitates the migration and diffusion of Li+ due to the expansion of Li+ pathway.
Pressed-plate carbonyl iron electrodes for rechargeable iron–air batteries have recently been described to undergo a considerable electrochemical formation before they attain a stable and competitive discharge capacity in concentrated alkaline electrolyte. In this study, the impact of the charging conditions on the discharge performance due to electrochemical formation was investigated. Based on the results, it is demonstrated that the preset charge capacity mainly determines the resulting discharge capacities of the porous electrodes in the steady state at the end of the formation period. Furthermore, the present study elucidates the electrode processes behind formation and expands the existing phenomenological model that has recently been established to explain the evolution of the discharge capacity. Finally, feasible criteria for the comparison of different anode architectures are discussed.
Demographics and economics in the next 20 years are being examined. They reflect a significant GDP growth and with this a strong demand for commercial aircraft not only in the US and Europe but across Asia and the Middle East. The demand will focus on more fuel efficient and more environmentally friendly vehicles. Significant progress is being made with the new regionals, narrow-body, and wide-body aircraft between now and the year 2020. Looking beyond, the world will examine new airplane architectures, new changes in propulsion systems, and higher thermal and propulsion efficiencies. Distributed propulsion options will come into play. With them, higher operating pressure gas generators will be developed and great attention will have to be given to highly integrated propulsion/airplane systems. Energy transfer requirements will lead to bigger gear systems as well as new hybrid systems. The new machines are forecasted to offer improvements in fuel efficiencies of over 40%. There are many technical challenges to make all these things happen. The aerospace engineers and scientists of today and tomorrow face unlimited opportunities to make a difference for what looks like a very exciting future.
Plate-like LiMnPO4 nanomaterial for Li-ion batteries is synthesised successfully via a facile solvothermal process in mixed water-diethylene glycol (DEG) solvents at 190 °C for 3 h. Experimental variables, including reaction time, reaction temperature and reactant mole ratio, are discussed in detail. A tentative reaction mechanism is proposed on the basis of the time dependent trials. It is found that, with the increase of reaction temperature, the formation of LiMnPO4 phase is accelerated and the reaction for synthesizing LiMnPO4 can be finished in a shorter time. Studies on the effect of reactant mole ratio further support the proposed mechanism. The electrochemical properties of obtained LiMnPO4 are examined after a carbon coating process. Electrochemical tests show that the obtained LiMnPO4 at 190 °C for 3 h exhibits better electrochemical performances than the LiMnPO4 synthesized at 170 °C for 4.5 h or 150 °C for 6 h. It is clear that an improved electrochemical performance can be obtained with the increase of reaction temperature and the decrease of reaction time. This result provides us thoughts and guidance to optimize the reaction conditions by harmonizing the reaction temperature and reaction time, which is beneficial for the practical application.
Predicting the highest battery temperature, the core temperature, is an important task for the safe operation of lithium-ion batteries. This prediction task is complicated by inherent system uncertainties that result in uncertain core temperature estimates. Aside from model, parameter and measurement uncertainty, this also includes uncertain user behavior in form of uncertain future discharge currents. However, measurable quantities like voltage, surface temperature or discharge current can potentially decrease the uncertainty in predicting the core temperature. The extent to which a measurement is able to decrease this estimation uncertainty, called data worth, depends on the uncertainty scenario. We conduct a model-based study to investigate the potential of voltage, current and surface temperature measurements to decrease core temperature estimation uncertainty. We use our previously developed stochastic, physically-based battery model to estimate the core battery temperature of a cylindrical LiFePO4-Graphite cell. The data worth is computed with the Preposterior Data Impact Accessor method. We find that the common input to state-of-charge estimation methods, i.e. voltage and current measurements, can theoretically partially substitute a temperature measurement, if the user behavior is anticipated to some degree. Moreover, we highlight the importance of adequately estimating the involved uncertainties when assessing the data worth of measurement quantities.
Publisher Summary This chapter deals with the designs of transformers isolated converters. Feedback Mechanism is applied to transformer circuit applications where the transformer is used for isolation, such as in off-line supplies. The output can be connected directly to the control integrated circuit (IC) in applications where isolation is not required. Most transformer circuits use the magnetic circuit of the transformer to provide electrical isolation of the secondary circuit from the primary circuit. Putting the control IC on the input side of the supply requires that feedback of the output voltage to the control IC has to cross an isolation barrier. If the IC is powered from an isolated supply, then the switch control must cross the isolation barrier. Using an optocoupler is the easiest way to transfer output voltage information across the isolation barrier to a control IC on the primary side. The usual method of compensating for the low optocoupler gain and the capacitance of the optocoupler is to use an amplifier and voltage reference on the isolated side of the supply. Another method of feedback isolation is to use a small power line transformer to generate an isolated auxiliary supply for the IC. The chapter also discusses flyback circuits; a flyback converter works in a fashion similar to a boost converter, where energy is stored in the inductor while the switch is on and the energy is delivered to the load when the switch turns off.
Wireless power transfer (WPT), which transmits power by an electromagnetic field across an intervening space, provides the prospect of new opportunities for electric vehicles (EVs) to enhance sustainable mobility. This review article evaluates WPT technology for EV applications from both technical and sustainability perspectives. The objectives of this review include: (1) to present the state-of-the-art technical progress and research bottlenecks in WPT development and applications in the transportation sector; (2) to characterize the demonstrations of the real-world deployment of WPT EV systems; and (3) to evaluate the sustainable performance and identify challenges and opportunities for improvement. From the technical perspective, progress on coil design, compensation topologies, and power electronics converters and control methods are reviewed with a focus on system performance. From the sustainability perspective, performance is defined in terms of energy, environmental, and economic metrics, and policy drivers and issues of health and safety are also examined.
The future commercialization and application of solid oxide fuel cell (SOFC) technologies requires the development of novel anode materials with excellent performance and stability at intermediate-temperatures with various fuels including hydrogen, syngas and particularly hydrocarbons. Whether by modifying the state-of-the-art Ni based anodes, or through exploring alternative metal cermet or ceramic based materials, wet impregnation/infiltration is shown to be one of the most effective approaches for both cell fabrication and performance optimization. This paper reviews most of the progress reported in the literature committed to the fabrication and optimization of SOFC anodes by wet impregnation for low temperature and/or hydrocarbon operation. The optimization of traditional nickel based anodes by adding excellent catalyst, the replacement of nickel by other inert metal or ceramic species, and some metal supported designs with impregnated catalyst are all presented and discussed, mainly focusing on the cell performance, redox and thermal stability, long-term reliability, carbon and sulfur tolerance of the anodes.
The hierarchical architecture of biomass activated carbon and metal oxides has attracted wide attention in the field of energy storage owing to its high specific surface area, good electrical conductivity, low cost and environmental friendliness. Herein, biomass carbon-based porous microsheets with thickness of 150–200 nm are obtained by ultrasonic crushing the carbonized poplar catkins (PC) micro-hollow fibers. The carbon microsheets were modified with polydopamine and further deposited with ultrathin nickel cobaltite nanosheets (NiCo2O4 NSs) to form a NiCo2O4 shell-carbon core sandwich composite. Benefiting from its characteristics, as-prepared hybrid electrodes exhibit significantly enhanced specific capacity (922.9C g−1 at 1 A g−1), excellent rate capability and good cycling stability. Furthermore, the hybrid supercapacitor was also fabricated with NiCo2O4 NSs@PD-PC and polydopamine-modified poplar catkins (PD-PC) carbon materials as positive electrode and negative electrode, respectively. It shows remarkable energy-storage characteristics, such as a high energy density of 39.1 W h kg−1 at the power density of 799.9 W kg−1, only 4.5% capacity loss after 5000 cycles, as well as a wide potential window of 0–1.6 V. Such excellent performance makes poplar catkins-derived carbon-based electrodes promise as one of the attractive candidates for high performance energy storage devices.
The state of charge (SOC) estimation is extremely important for the wide commercialization and safe operation of electric vehicle (EV), especially under cold conditions, which is also a critical technology for battery system in EVs used in the 2022 Beijing winter Olympics. Three efforts have been made in this paper: (1) A general joint estimation framework with dual estimators is set up. Based on this frame, a joint algorithm using the recursive least square (RLS) and the adaptive H infinity filter (AHIF) is realized. (2) Four filter-based algorithms have been systematically compared and analyzed at the wide temperature range. The results show that RLS-AHIF algorithm has better performance for SOC estimation even at low temperatures, such as −10 °C, and the SOC error is within 3.5%. (3) A hardware-in-loop validation platform including the battery management system (BMS) and battery test instruments has been built to verify the proposed method. The results from the platform show that the maximum error of SOC is less than 2% at 0 °C and 25 °C. Consequently, the proposed algorithm can achieve the application over a wide temperature range in an actual BMS.
Rural electrification and the provision of low cost, low emission technology in developing countries require decision makers to be well informed on the costs, appropriateness and environmental credentials of all available options. While cost and appropriateness are often shaped by observable local considerations, environmental considerations are increasingly influenced by global concerns which are more difficult to identify and convey to all stakeholders. Life cycle assessment is an iterative process used to analyse a product or system. This study iteratively applies life cycle assessment (LCA) to a 3 kW community hydroelectric system located in Huai Kra Thing (HKT) village in rural Thailand. The cradle to grave analysis models the hydropower scheme’s construction, operation and end of life phases over a period of twenty years and includes all relevant equipment, materials and transportation. The study results in the enumeration of the environmental credentials of the HKT hydropower system and highlights the need to place environmental performance, and LCA itself, in a proper context. In the broadest sense, LCA results for the HKT hydropower system are found to reflect a common trend reported in hydropower LCA literature, namely that smaller hydropower systems have a greater environmentally impact per kWh – perform less well environmentally - than larger systems. Placed within a rural electrification context, however, the HKT hydropower system yields better environmental and financial outcomes than diesel generator and grid connection alternatives.
The objective of this study is to describe the main battery-recycling processes currently used and those that are being developed. Technological options are presented for the recycling of lead acid, Zn–C, Zn–MnO2, nickel metal hydride, nickel–cadmium, lithium and lithium ion batteries.
Global uptake of solar PV has risen significantly over the past four years, motivated by increased economic feasibility and the desire for electricity self-sufficiency. However, significant uptake of solar PV could cause grid balancing issues. A system comprising Stirling engine combined heat and power, solar PV and battery storage (SECHP–PV–battery) may further improve self-sufficiency, satisfying both heat and electricity demand as well as mitigating potential negative grid effects. This paper presents the results of a simulation of 30 households with different energy demand profiles using this system, in order to determine: the degree of household electricity self-sufficiency achieved; resultant grid demand profiles; and the consumer economic costs and benefits. The results indicate that, even though PV and SECHP collectively produced 30% more electricity than the average demand of 3300kWh/yr, households still had to import 28% of their electricity demand from the grid with a 6kWh battery. This work shows that SECHP is much more effective in increasing self-sufficiency than PV, with the households consuming on average 49% of electricity generated (not including battery contribution), compared to 28% for PV. The addition of a 6kWh battery to PV and SECHP improves the grid demand profile by 28% in terms of grid demand ramp-up requirement and 40% for ramp-downs. However, the variability of the grid demand profile is still greater than for the conventional system comprising a standard gas boiler and electricity from the grid. These moderate improvements must be weighed against the consumer cost: with current incentives, the system is only financially beneficial for households with high electricity demand (>4300kWh/yr). A capital grant of 24% of the installed cost of the whole micro-generation system is required to make the system financially viable for households with an average electricity demand (3300kWh/yr).
A battery energy storage system (BESS) is usually integrated with a wind farm to smooth out its intermittent power in order to make it more dispatchable. This paper focuses on the development of a scheme to minimize the capacity of BESS in a distributed configuration using model predictive control theory and wind power prediction. The purpose to minimize the BESS capacity is to reduce the overall cost of the system as the capacity of BESS is the main cost driver. A new semi-distributed BESS scheme is proposed and the strategy is analyzed as a way of improving the suppression of the fluctuations in the wind farm power output. The scheme is tested for similar and dissimilar wind power profiles, where the turbines are geographically located closer and further from each other, respectively. These two power profiles are assessed under a variety of hard system constraints for both the proposed and conventional BESS configurations. Based on the simulation results validated with real-world wind farm data, it has been observed that the proposed semi-distributed BESS scheme results in the improved performance as compared with conventional configurations such as aggregated and distributed storage.
An experiment was performed to study the power production by a Darrieus type turbine of the Dutch company Water2Energy in a tidal estuary. Advanced instrumentation packages, including mechanical sensors, acoustic Doppler current profiler (ADCP), and velocimeter (ADV), were implemented to measure the tidal current velocities in the approaching flow, to estimate the turbine performance and to assess the effect of turbulence on power production. The optimal performance was found to be relatively high (C p ∼ 0.4). Analysis of the power time history revealed a large increase in magnitude of power fluctuations caused by turbulence as the flow velocity increases between 1 and 1.2 m/s. Turbulence intensity does not alone capture quantitative changes in the turbulent regime of the real flow. The standard deviation of velocity fluctuations was preferred in assessing the effect of turbulence on power production. Assessing the scaling properties of the turbulence, such as dissipation rate, ε , the integral lengthscale, L , helped to understand how the turbulence is spatially organized with respect to turbine dimensions. The magnitude of power fluctuations was found to be proportional to L and the strongest impact of turbulence on power generation is achieved when the size of turbulent eddies matches the turbine size.
In the past decade the scientific community has showed considerable interest in the development of implantable medical devices such as muscle stimulators, neuroprosthetic devices, and biosensors. Those devices have low power requirements and can potentially be operated through fuel cells using reactants present in the body such as glucose and oxygen instead of non-rechargeable lithium batteries. In this paper, we present a thin, enzyme-free fuel cell with high current density and good stability at a current density of 10μAcm−2. A non-enzymatic approach is preferred because of higher long term stability. The fuel cell uses a stacked electrode design in order to achieve glucose and oxygen separation. An important characteristic of the fuel cell is that it has no membrane separating the electrodes, which results in low ohmic losses and small fuel cell volume. In addition, it uses a porous carbon paper support for the anodic catalyst layer which reduces the amount of platinum or other noble metal catalysts required for fabricating high surface area electrodes with good reactivity. The peak power output of the fuel cell is approximately 2μWcm−2 and has a sustainable power density of 1.5μWcm−2 at 10μAcm−2. An analysis on the effects of electrode thickness and inter electrode gap on the maximum power output of the fuel cell is also performed.
The debate on mobile telephone safety continues. Most epidemiological studies investigating health effects of radiofrequency (RF) radiation emitted by mobile phone handsets have been criticised for poor exposure assessment. Most of these studies relied on the historical reconstruction of participants’ phone use by questionnaires. Such exposure assessment methods are prone to recall bias resulting in misclassification that may lead to conflicting conclusions. Although there have been some studies using software-modified phones (SMP) for exposure assessment in the literature, until now there is no published work on the use of hardware modified phones (HMPs) or RF dosimeters for studies of mobile phones and health outcomes. We reviewed existing literature on mobile phone epidemiology with particular attention to exposure assessment methods used. Owing to the inherent limitations of these assessment methods, we suggest that the use of HMPs may show promise for more accurate exposure assessment of RF radiation from mobile phones.
In this work, we report a very simple method to in situ prepare the Fe1−x Ni x (x =0, 0.3, 0.4, 0.5, 0.7 and 1) nano-alloys as the catalysts for H2 generation from the aqueous NH3BH3 solution under ambient atmosphere at room temperature. The prepared nano-alloys possess Pt-like high catalytic activity, especially for the specimen of Fe0.5Ni0.5, with which the hydrolysis of NH3BH3 would totally complete in only 2.2min. Moreover, these catalysts can be easily magnetically separated for recycle purpose, and can almost keep the same high activity even after 5 times of recycle under ambient atmosphere. Such alloy catalysts are expected to be useful for fuel cells, metal–air batteries and electrochemical sensors. Moreover, the concepts behind these preliminary results present a wide range of possibilities for the further development of synthesis of air and water-stable magnetic nano-alloys.
Graphite intercalation intercalated with metal alloys able to alloy reversibly lithium constitute a large set of new anodic materials for lithium-ion batteries of significantly improved reversible capacities. Especially, graphite intercalated with cesium–antimony alloys can be used as materials for anodes in lithium-ion batteries. Electrochemical insertion of lithium in such chemically modified precursors shows that lithium both intercalates in the empty van der Waals spaces of graphite and alloys reversibly with antimony. The total electrochemical reversible capacities, measured between 0 and 2 V vs Li+/Li, close to 700 mAh g−1 have been currently obtained.
As the cathode material of Na-ion batteries based on conversion reaction, the iron-based fluorides have attracted ever-increasing attentions. Nevertheless, its poor electronic conductivity and side reactions usually lead to sluggish reaction kinetics and rapid capacity decay during cycling process, and thus limiting its practical application. Herein, a hollow porous FeF3·0.33H2O microsphere is successfully prepared via a solvothermal route and further modified with AlPO4. The results show that appropriate modification treatment can satisfactorily decrease charge-transfer resistance and enhance sodium diffusion rate. Compared with the pristine FeF3·0.33H2O, 4 wt.% AlPO4-coated sample shows a noticeable initial discharge capacity of 290 mAh g−1 in the range of 1.2–4.0 V, outstanding cycling stability (211 mAh g−1 after 80 cycles) and excellent rate capability (167 mAh g−1 at 2.0 C). The excellent electrochemical properties can be ascribed to the distinctively hierarchical mesoporous hollow structure of FeF3·0.33H2O, which facilitates electrolyte permeation and rapid ionic as well as electronic transmission. Besides, the multifunctional AlPO4 modification layer can improve the electronic conductivity, suppress the surface side reaction and buffer the volume changes during cycling processes, thus boosting the enhancement of the electrochemical performance. Therefore, this study offers a new strategy for improving and modifying the electrochemical performances of cathode materials for sodium-ion batteries.
Two important themes for future clinical research in the neuropsychology of epilepsy are proposed: (1) the neurobiological abnormalities that underlie neuropsychological impairment in people with epilepsy, and (2) neuropsychological status of persons with new-onset epilepsy.