batterydata/paper-abstracts huggingface dataset:
In a previous paper, we developed a method to produce a physics-based one-dimensional discrete-time state-space reduced-order model (ROM) of a lithium-ion cell. The method relies on linearizing the standard porous-electrode equations around a fixed state-of-charge (SOC) and operating temperature setpoint. The ROM is able to track a highly dynamic input accurately near the linearization setpoint, but its performance degrades as either the cell's SOC or temperature move away from this linearization point. This paper describes a way to extend the accuracy of the ROM over a wide range of SOCs and temperatures using a model-blending approach. Our results demonstrate that the approach accurately models the cell's voltage and internal electrochemical variables over a wide range of temperature and SOC, with little added computational complexity.
This study describes the use of a cognitive-behavioral computer-administered self-help program with minimal therapist contact for public speaking anxiety. Participants (N = 10) with social phobia, as measured by a structured clinical interview, completed the self-help program in an open clinical trial. The program was delivered via a CD-ROM during individual sessions at an outpatient clinic, including 4 sessions of psychoeducation/cognitive therapy and 4 sessions of exposure therapy using a virtual audience presented on a computer screen. A therapist was available in another room to answer questions and to debrief for up to 10 minutes after each session. Participants completed standardized self-report questionnaires assessing social anxiety at pretreatment, posttreatment, and 3-month follow-up. Participants also completed measures of computer usability. Results showed decreases on all self-report measures of social anxiety from pre- to posttreatment, which were maintained at follow-up (n = 8). Participants also reported that they were satisfied with treatment, that they felt improved after treatment, and that the computer program was user-friendly. This study provides preliminary evidence that a computer-administered cognitive-behavioral-based program that includes minimal therapist contact may reduce public speaking anxiety and suggests that further research with a controlled design is needed.
The fast evolution of portable electronic devices and micro-electro-mechanical systems (MEMS) requires multi-functional microscale energy sources that have high power, high energy, long cycle life, and the adaptability to various substrates. Nanostructured thin-film lithium-ion batteries and electrochemical capacitors (ECs) are among the most promising energy storage devices that can meet these demands. This perspective presents an overview of recent progresses and challenges associated with the development of binder-free, carbon-based nanostructured electrodes prepared from layer-by-layer (LbL) electrostatic assembly, which provide enhanced gravimetric and volumetric energy for ECs and enhanced power capabilities for batteries. Based on promising findings for thin electrodes of several microns in thickness, LbL-based electrodes could also potentially be envisioned for portable electronics, electrified transportation, and load-leveling applications if successful scale-up to tens or hundreds of microns can be achieved.
In this study, we used the electrochemical impedance spectra to evaluate the anode performance of direct formic acid fuel cell (DFAFC), and how its anode charge transfer resistance (R anode,ct) and electrolyte resistance (R ele) are affected by various cell operating parameters. The parameters investigated in this study include the anode overpotentials, cell operation times, formic acid feed concentrations and cell temperatures. The anode impedance spectra demonstrated that the R anode,ct and R ele are low for the DFAFC using 5M formic acid feed concentration, which leads to its high power density output of 250mWcm−2 at 0.35V and 30°C. The high performance of the DFAFC demonstrates that it has a great potential for portable power applications. The R anode,ct increases gradually as either the cell operation time increases or the formic acid feed concentration is raised from 10 to 15M, which leads to a deactivation of the anode electrode, resulting in reduction of overall cell performance. However, these deactivation processes are reversible and the cell performance can be easily reactivated.
Electron transfer and lithium ion diffusion rates are the key factors leading to sluggish electrochemical kinetics of LiMn0.8Fe0.2PO4. In this work, we have successfully synthesized graphene-embedded LiMn0.8Fe0.2PO4 composites via a facile graphene oxide assisted solvothermal route associated with carbonthermal treatment. The effect of graphene on the morphology, crystalline structure as well as electrochemical properties of LiMn0.8Fe0.2PO4 is investigated. It can be found that the introducing graphene can reduce the particle size to form LiMn0.8Fe0.2PO4 nanocrystals without destroying the crystalline structure of LiMn0.8Fe0.2PO4. And the LiMn0.8Fe0.2PO4 nanocrystals dispersed on the graphene sheets which were further cross-linked via the oxygen-containing groups of GO as cross-linking sites, resulting in that graphene sheets embedded in the LiMn0.8Fe0.2PO4 composites. Benefiting from the LiMn0.8Fe0.2PO4 nanocrystal and embedded graphene, the interconnected conducting network referred to electron and lithium ion transport pathways can be improved, resulting in enhanced electrochemical performance. The graphene embedded LiMn0.8Fe0.2PO4 composite displays a high discharge capacity of 163.5, 149.2, 136.0, 120.6, 100.1 and 84.5 mA h g-1 at various rate of 0.1C, 0.5C, 1C, 2C, 5C and 10C, respectively. Meanwhile, it still maintains a reversible capacity of around 120 mA h g-1 after 100 cycles at a rate of 1C.
Reducing heat accumulation within vehicles and ensuring appropriate vehicular temperature levels can lead to enhanced vehicle fuel economy, range, reliability, longevity, passenger comfort, and safety. Advancements in vehicle thermal management remain key as new technologies, consumer demand, societal concerns, and government regulations emerge and evolve. This study summarizes several recent advances in vehicle thermal management technology and modeling, with a focus on three key areas: the cabin, electronics, and exterior components of vehicles. Cabin-related topics covered include methods for reducing thermal loads and improving heating, ventilation, and air-conditioning (HVAC) systems; and advancements in window glazing/tinting and vehicle surface treatments. For the thermal management of electronics, including batteries and insulated-gate bipolar transistors (IGBTs), active and passive cooling methods that employ heat pipes, heat sinks, jet impingement, forced convection, and phase-change materials are discussed. Finally, efforts to model and enhance the heat transfer of exterior vehicular components are reviewed while considering drag/friction forces and environmental effects. Despite advances in the field of vehicle thermal management, challenges still exist; this article provides a broad summary of the major issues, with recommendations for further study.
Off-grid electricity generation using renewable energy technologies has become a more reliable source to fulfill the needs of rural areas at limited level without considering conventional resources. The main purpose of this study was to propose an economical and optimized design for electricity generation using hybrid energy source PV/Biomass for an agricultural farm and a residential community centered in a small village of district Layyah in the Punjab province of Pakistan. The electric load data was collected for the irrigation and residential needs. Hybrid Optimization Model for Electric Renewable (HOMER) was used to design and perform techno-economic analysis to meet the load requirements using PV/biomass hybrid configuration. The solar irradiance data and the available biomass potential on the farm was used in the HOMER software to perform the analysis. Total net present cost (NPC) and cost of electricity (COE) were obtained as a solution by the HOMER analysis and then these results were refined further by performing sensitivity analysis. Sensitivity parameter such as biomass potential, biomass price, solar irradiance and variations in loads were used in the sensitivity analysis. This analysis compares the performance of the system and shows that system is techno-economically viable based on the net present cost and cost of energy.
Symmetric cells provide complementary means to probe electrochemical processes in lithium-ion batteries. Here, positive and negative electrodes harvested from conventional oxide/graphite cells are cross-paired, and the assembled reference-electrode-bearing symmetric cells are cycled/aged. For graphite symmetric cells, the electrode potentials and impedances remain nearly constant during calendar aging and the parasitic currents are typically small. However, at higher cell voltages when the “positive” graphite potential exceeds 1.0 V vs. Li/Li+, the capacity loss is higher, indicating that even a mild (but prolonged) overdischarge can damage the SEI. For the layered-oxide symmetric cells there are strong parasitic currents and a persistent slide of the electrode potential over time during calendar aging. Significant cell impedance rise, especially at higher hold voltages, is also observed. Curiously, the impedance rise in the “negative” oxide electrode, which experiences potentials below 4.0 V vs. Li/Li+, is greater than in the “positive” oxide electrode that experiences much higher potentials. We postulate that electrolyte oxidation is responsible for the behavior of these oxide symmetric cells, as it supplies electrons (that bind more Li+ into the cathode, causing the potential slide) and protons (that contribute to impedance rise). These insights can guide the development of future lithium-ion cell chemistries.
Poorly crystalline porous δ-MnO2 is synthesized by hydrothermal route from a neutral aqueous solution of KMnO4 at 180°C and the reaction time of 24h. The as-synthesized sample and also the sample heated at 300°C have nanopetals morphology with large surface area. On heating at temperatures ⩾400°C, there is a decrease in BET surface area and also a change in morphology from nanopetals to clusters of nanorods. Furthermore, the poorly crystalline δ-MnO2 converts into well crystalline α-MnO2 phase. The electrochemical lithium intercalation and de-intercalation studies in a non-aqueous electrolyte provide a high discharge specific capacity (275mAhg−1) at a specific current of 40mAg−1 for the poorly crystalline δ-MnO2 samples. The rate capability is also high. There is a decrease in capacity on repeated charge–discharge cycling. The specific capacity values of the crystalline α-MnO2 samples are considerably less than the values of poorly crystalline δ-MnO2 samples. Thus, the hydrothermal route facilitates preparation of poorly crystalline electrochemically active porous MnO2.
Patient outcome after serious brain injury is highly variable. Following a period of coma, some patients recover while others progress into a vegetative state (unresponsive wakefulness syndrome) or minimally conscious state. In both cases, assessment is difficult and misdiagnosis may be as high as 43%. Recent advances in neuroimaging suggest a solution. Both functional magnetic resonance imaging and electroencephalography have been used to detect residual cognitive function in vegetative and minimally conscious patients. Neuroimaging may improve diagnosis and prognostication. These techniques are beginning to be applied to comatose patients soon after injury. Evidence of preserved cognitive function may predict recovery, and this information would help families and health providers. Complex ethical issues arise due to the vulnerability of patients and families, difficulties interpreting negative results, restriction of communication to “yes” or “no” answers, and cost. We seek to investigate ethical issues in the use of neuroimaging in behaviorally nonresponsive patients who have suffered serious brain injury. The objectives of this research are to: (1) create an approach to capacity assessment using neuroimaging; (2) develop an ethics of welfare framework to guide considerations of quality of life; (3) explore the impact of neuroimaging on families; and, (4) analyze the ethics of the use of neuroimaging in comatose patients.
With the environmental advantages of solar energy, the use of solar photovoltaic (PV) in residential electricity generation is encouraged by Australian governments incentives, however, what number of residents benefit from installing a grid-connected PV system and how much electricity generated by such a system is not clearly understood yet. This study aims to investigate the economic, technical and environmental performance of residential PV system running under the Queensland (Australia) climatic conditions, and optimize the size and slope of PV array in the system. The solar irradiation data of the 4 typical climate zones of Queensland, including tropical, sub-tropical, hot arid, and warm temperature zone, are investigated. Using global solar irradiation as solar energy resource data, the price of PV devices, batteries, converters, and grid electricity tariff and sale-back tariff as economic analysis inputs, the system is simulated and optimized by HOMER software. The optimized system not only satisfies the typical residential load of 23 kWh per day but also meets the requirement of minimizing the total costs of system investment and electricity consumption during the system's lifetime. It is found that under the specific climatic conditions of the eleven main cities of Queensland, a PV system is an effective way to decrease electricity bills and mitigate carbon dioxide emission. In particular, a 6 kW PV system in Townsville is able to deal with 61% of the total electricity load and conserves more than 90% of electricity payments and reduce approximately 95% of carbon dioxide emission. It is also found that for all the cities the systems with 20–25 degrees of slope have the best performance including the least cost of energy (COE) and the least carbon dioxide emission.
The world’s largest deposits of lithium lie in brines found underneath salt flats in the desert between Chile, Argentina and Bolivia. Globally, lithium may reduce fossil fuel use by making batteries for cars and renewable energy storage more affordable. This article analyzes ongoing debates about lithium in these three countries to identify what hopes, fears and expectations different stakeholders are bringing to debates about lithium. My approach builds on the idea of resource imaginaries, particularly the concept of sociotechnical imaginaries that highlights the importance of science and technology to projections of desirable futures. I analyze the tensions, visions and metaphors used by different stakeholders, including activists, the media, and state and industry officials, to imagine and thus legitimate lithium extraction. This study finds three co-existing positions in these debates: lithium as a commodity, as a strategic resource or as the subject of a sociotechnical imaginary. Chile, Argentina and Bolivia are converging on the last of these, best described as a reimagining of the relationship between mining and development in which lithium, through innovation and industry, will redefine the relationship between Latin American economies and global markets. This imaginary projects a binary between raw and industrial materials and deterministically assumes that science and technology will transform the former into the latter. Disagreements and challenges notwithstanding, the article argues that this imaginary is evidence of a crisis of confidence in development that is creating space for a more dynamic debate about the social value of mining and the proper role of the state in development. This convergence will have also implications for how sustainable, equitable and reliable lithium production will be.
Nano-sized LiMn2O4 spinel with well crystallized homogeneous particles (60nm) is synthesized by a resorcinol–formaldehyde route. Micro-sized LiMn2O4 spinel with micrometric particles (1μm) is prepared by a conventional solid-state reaction. These two samples are characterized by XRD, SEM, TEM, BET, and electrochemical methods. At current rate of 0.2C (1C =148mAg−1), a discharge capacity of 136mAhg−1 is obtained on the nano-sized LiMn2O4, which is higher than that of micro-sized one (103mAhg−1). Furthermore, compared to the micro-sized sample, nano-sized LiMn2O4 shows much better rate capability, i.e. a capacity of 85mAhg−1, 63% of that at 0.2C, is realized at 60C. The excellent high rate performance of nano-sized LiMn2O4 spinel may be attributed to its impurity-free nano-sized particles, higher surface area and well crystalline. The outstanding electrochemical performances demonstrate that the nano-sized LiMn2O4 spinel will be the promising cathode materials for high power lithium-ion batteries used in hybrid and electric vehicles.
While liquid metal batteries are attractive options for grid-scale energy storage applications as they have flexible siting capacities and small footprints, the compatibility between structural materials such as current collectors and negative electrode such as sodium is one of major issues for liquid metal batteries. Non-metallic elements such as carbon, oxygen, and nitrogen in the liquid sodium influence the material behaviors of the cell construction materials in the battery system. In this study, the compatibility of structural materials with sodium is investigated in high temperature liquid sodium, and electrochemical impedance spectroscopy (EIS) is used to monitor in-situ the corrosion behavior at the surface of materials in sodium. Chemical vapor deposition (CVD) coatings of SiC and Si3N4 are applied as protective barriers against dissolution and corrosion on the steel surface. The results show that CVD coating of Si compounds can delay corrosion of steel in high temperature liquid sodium comparing to the result of as-received specimens, while SiC coating is more durable than Si3N4 coating in high temperature liquid sodium.
The integration of renewable energy systems has increased in the last decades because of the need for new energy sources freely available and environmental friendly. In this sense, photovoltaic-wind hybrid energy systems are an attractive solution, especially in places with good sun and wind resources. However, due to the stochastic and intermittent behavior of these sources, it is necessary to analyze systems' reliability. In this paper, a new reliability indicator is proposed, based on the minimum hourly electric power obtained from the wind and solar radiation using a probabilistic approach. This indicator is compared with other indicators and the results showed that it increases system reliability by maximizing the use of renewable sources.
Lithium-ion batteries show promise for use in energy storage applications in power stations. There are two current concerns with power stations: cost and safety. The cost problem is being gradually solved, but safety is always a challenge in the large-scale utilization of lithium-ion batteries. Battery management systems, which rely mainly on voltage and current monitoring, are an effective way to ensure the safe operation of batteries. Strain is an equally critical parameter for battery state monitoring to improve safety and utilization efficiency. In this paper, we present a new high precision method of strain monitoring based on a fiber Bragg grating sensor. The sensor consists of a fiber Bragg grating and a sensitivity-enhancing mechanism, making it more sensitive than the bare fiber Bragg grating sensor. A comparison test between our proposed sensor and bare fiber Bragg grating sensor have confirmed its performance in monitoring the strain in a battery. Our investigation into the relationship between strain and state-of-charge/depth-of-discharge suggests that the strain increases as the state-of-charge increases, and decreases as the depth-of-discharge increases. This method is a promising tool for providing strain data on power batteries for battery management systems.
Electrolyte ionic diffusivity significantly affects the power density and useable energy density of a lithium ion battery. During usage, electrolyte can decompose, leading to reduced ionic diffusivity. Understanding the degradation mechanism and its effect on ionic diffusivity is important for both battery design optimization to provide superior performance with a long cycle life and for better battery management during usage to extend the battery life. In this research, the ionic diffusivity of key electrolytes and their degradation, including DMC-LiPF6, EMC-LiPF6 and DEC-LiPF6, are quantitatively predicted with classical and ReaxFF molecular dynamics simulations. The electrolyte solvent structures and reaction pathways are characterized. The effect of temperature, salt concentration and degree of thermal degradation on electrolyte ionic diffusivity are identified. A list of gas-phase, solvent-phase and solid-phase degradation products are categorized. DMC-LiPF6 shows the highest thermal stability, while DEC-LiPF6 shows the lowest thermal stability because of a large amount of –CH3CH2 group in the molecule. PF 6 - tends to decompose first. The decomposed product of PF5 can further lead to C–O bond breaking in solvent molecules, causing them to decompose into products composed of smaller molecules. Simulations show that the diffusion coefficients of cations and anions decrease with thermal degradation. The mechanism is found to be related to the clustering of Li+, R-O- and (R–OCO2)-, which impedes ion diffusion in the electrolyte. This paper provides a quantitative understanding of electrolyte thermal degradation, revealing the underlying mechanisms and effects on electrolyte properties at the atomistic level by a systematic comparative study for the first time. The approach will provide valuable guidance to the development of lithium ion batteries.
Solar energy is one of the most powerful sources for many sustainable applications. Recently, efficient water distillation has attracted significant attention. The fresh water productivity depends on how efficiently the system harvests the incoming solar energy and converts it into useful heat. An ideal blackbody is capable of perfectly absorbing all wavelengths. The absorbed incident photons are converted into thermal energy. To approach the maximum solar absorption of a blackbody, efficient nanomaterials were developed with enhanced absorption in ultraviolet (UV)-visible to near infrared (NIR). Nanomaterials with broadband absorption, efficient heat transfer, minimum surface energy loss, and energy storage have recently emerged exhibiting accelerated the evaporation rate. These nano-enabled materials direct attention back towards traditional solar stills for future sustainable water evaporation for clean water production. Herein, novelty of the review includes (1) direct solar steam generation of highly efficient broadband materials, (2) energy exchange materials including nanoparticles & nano-fluids, (3) energy storage materials including phase change materials & nano-enabled-phase change materials and (4) other sensible energy storage materials for desalination. One result was that the local surface plasmon resonance (LSPR) effect in plasmonic metals and efficient heat trapping capabilities of carbon materials show high evaporation rates.