batterydata/paper-abstracts huggingface dataset:
Inductive Contactless Power Transmission (ICPT) may suffer considerable power loss due to eddy currents in seawater when applied undersea rather than on land. The loss of power, which is harmful to transmission efficiency, is closely related to the transmission frequency. However, the relationship between the transmission frequency and the efficiency has rarely been studied. In this paper, we analytically deduce the power transmission efficiency in air and the power loss of ICPT in seawater. Based on the theoretical calculation and analysis, guidelines are provided to select the optimum frequency to maximise the efficiency. A case study is then performed to numerically determine the optimum frequency for an undersea ICPT system. Laboratory experiments are conducted to confirm the theoretical results. A prototype ICPT system power is designed and built. A lake trial demonstrates that the designed system is able to transmit power contactless to actual undersea observation network equipment underwater with an efficiency of approximately 85% and a 5mm gap distance.
Functionalized disiloxane compounds were synthesized by attaching oligo(ethylene glycol) chains, –(CH2CH2O)– n , n =2–7, via hydrosilation, dehydrocoupling, and nucleophilic substitution reactions and were examined as non-aqueous electrolyte solvents in lithium-ion cells. The compounds were fully characterized by 1H, 13C, and 29Si nuclear magnetic resonance (NMR) spectroscopy. Upon doping with lithium bis(oxalato)borate (LiBOB) or LiPF6, the disiloxane electrolytes showed conductivities up to 6.2×10−4 Scm−1 at room temperature. The thermal behavior of the electrolytes was studied by differential scanning calorimetry, which revealed very low glass transition temperatures before and after LiBOB doping and much higher thermal stability compared to organic carbonate electrolytes. Cyclic voltammetry measurements showed that disiloxane-based electrolytes with 0.8M LiBOB salt concentration are stable to 4.7V. The LiBOB/disiloxane combinations were found to be good electrolytes for lithium-ion cells; unlike LiPF6, LiBOB can provide a good passivation film on the graphite anode. The LiPF6/disiloxane electrolyte was enabled in lithium-ion cells by adding 1wt% vinyl ethylene carbonate (VEC). Full cell performance tests with LiNi0.80Co0.15Al0.05O2 as the cathode and mesocarbon microbead (MCMB) graphite as the anode show stable cyclability. The results demonstrate that disiloxane-based electrolytes have considerable potential as electrolytes for use in lithium-ion batteries.
This work studies the dependence of the electrical conductivity of HClO4 doped polyaniline (PAni) on the potential in an aprotic electrolyte (1M LiClO4 in EC/DMC) and establishes that it possesses a sufficiently high conductivity within a narrow potential range 3.3–3.5V vs. Li/Li+, beyond which its resistance increases sharply. It is shown that PAni, as a component of lithium battery electrodes, could be subjected to stable charge-discharge cycling in the 1.0–4.2V vs. Li/Li+ potential range and that decrease of the lower limit of the potential range below 1.0V could lead to the formation of an SEI layer, which causes the irreversible reduction of PAni electrochemical performance.
The purpose of this research is to perform economic analysis, formulate an optimization model, and determine optimal operating strategies for smart microgrid systems. Microgrid systems are electricity supply systems that integrate distributed renewable energy production for local demand. Microgrids are able to reduce transmission losses and improve utilization efficiency of electricity and heat. Further, greenhouse gas emissions are reduced by utilizing an efficient power generation microgrid system. This study presents an energy management model that is used to determine optimal operating strategies with maximum profit for a microgrid system in Taiwan. The smart microgrid system is equipped with energy storage devices, photovoltaic power, and wind power generation systems. Sensitivity analyses of investment in storage capacity and growth in electricity demand are conducted for the smart microgrid model. The results show that appropriate battery capacity should be determined on the basis of both battery efficiency and power supply.
Abstract This chapter presents the bases of exergy and obtains expressions for its calculation. The meaning of the First Law and the Energy Conservation equations are developed, for closed and open systems. Next, Second Law is presented, reviewing its classical formulation and the entropy concept. The meaning of the distinct quality of the different forms of energy and the concept of exergy are afterwards presented. A precise definition of the reference environment and the difficulties encountered in this regard are shown. The expression for calculating the exergy of a heat flux is given, as well as the exergy associated with the internal energy and several examples are developed. A detailed exergetic study of thermal radiation is then made. For open systems, the expression of the maximum work associated with a flow is derived. The general exergy balance in an open system is then considered. Next, different ways of defining performance are given. The chapter ends with an analysis of the mechanisms of irreversibilities.
In this work, we reported an asymmetric supercapacitor in which active carbon (AC) was used as a positive electrode and carbon-coated LiTi2(PO4)3 as a negative electrode in 1M Li2SO4 aqueous electrolyte. The LiTi2(PO4)3/AC hybrid supercapacitor showed a sloping voltage profile from 0.3 to 1.5V, at an average voltage near 0.9V, and delivered a capacity of 30mAhg−1 and an energy density of 27Whkg−1 based on the total weight of the active electrode materials. It exhibited a desirable profile and maintained over 85% of its initial energy density after 1000 cycles. The hybrid supercapacitor also exhibited an excellent rate capability, even at a power density of 1000Wkg−1, it had a specific energy 15Whkg−1 compared with 24Whkg−1 at the power density about 200Wkg−1.
Large-scale three-dimensional (3D) hybrid microelectrodes have been fabricated through modified carbon microelectromechanical systems (Carbon-MEMS) process and electrochemical deposition method. Greatly improved electrochemical performance has been shown for the 3D photoresist-derived carbon microelectrodes with the integration of carbon nanotubes (CNTs) and manganese dioxide (MnO2). The electrochemical measurements of the microelectrodes indicate that the specific geometric capacitance can reach up to 238 mF cm−2 at the current density of 0.5 mA cm−2. The capacitance loss is less than 18.2% of the original value after 6000 charge–discharge cycles. This study shows that stacking of MnO2 film and integrating of CNTs to the 3D glassy carbon microelectrodes have great potential for on-chip microcapacitors as energy storage devices, and the presented approach is promising for large-scale and low-cost manufacturing.
Recent studies point out contradictions between classical Butler–Volmer kinetics and the charge transfer kinetics of lithium intercalation in host materials. In this work the charge transfer kinetics of lithium intercalation in LiFePO4 are investigated using current controlled electrochemical impedance spectroscopy with varying amplitudes. The results point out a significant impact of ohmic and diffusion contributions to the total overpotential which is normally extracted from constant current charging – discharging experiments to determine Tafel-plots, exchange currents and charge transfer coefficients. By the accurate separation of the activation overpotential from the total overpotential the authors are able to show that the charge transfer kinetics of lithium intercalation in LiFePO4 perfectly obey the Butler–Volmer equation.
We synthesize a carbon nanotubes (CNTs)/Co3O4 nanocomposite and demonstrate its electrochemical properties as an effective catalyst in Li-air cells. In particular, we introduce polydopamine as a binding agent (or reaction assistant) for CNTs and a catalyst with redox properties (Co3O4). Polydopamine coated on the surface of CNTs is expected to offer hydrophilicity and reactivity with oxide-sources. The CNTs/Co3O4 composite prepared using polydopamine layers shows homogeneously dispersed Co3O4 nanoparticles on the surface of the CNTs, thereby confirming that our new facile approach allows effective interaction between the carbon support and the oxide component. The air electrode containing polydopamine-assisted CNTs/Co3O4 composites shows superior catalytic activities in Li-air cells. This can be attributed to the wide catalytic-active area that provides well-dispersed nanosized Co3O4 particles as well as to the reduced contact resistance as a result of the close contact between CNTs and oxide (Co3O4).
LiFePO4/carbon composite electrode was prepared and applied to the dry polymer electrolyte. Enhanced low-temperature performance of LiFePO4 was achieved by modifying the interface between LiFePO4 and polymer electrolyte. The molecular weight of the polymer and the salt concentration as the Li/O ratio were optimized at 3×105 and 1/10, respectively. Impedance analysis revealed that a small resistive component occurred in the frequency range of the charge transfer process. The reversible capacity of the laminate cell was 140mAhg−1 (C/20) and 110mAhg−1 (C/2) at 40°C, which is comparable to the performance in the liquid electrolyte system.
This paper presents a double-layer smart charging management algorithm (SCMA) for electric vehicles in working place parking lots considering smart grid concept. This model enables safe and controlled charging, which satisfies both power grid and drivers’ needs comprehensively. First level of SCMA controls each transformer power demand, transformer capacity, charging station status and the shortest way to reach suitable charger. Second level of SCMA is used during the charging process in order to provide cost-effective and reliable charging as well as less impact on power grid. The proposed SCMA strategy successfully routes the electric vehicles (EVs) to the most suitable charging point, decreases the charging costs and prevents the overloading of transformers. In this study, a comparison regarding the impacts of the whole charging process of the EVs on the power grid and drivers’ requests with/without the proposed SCMA is presented and the results are discussed in detail.
Efficiencies of perovskite solar cells (PSCs) are now hitting such high levels that scalable fabrication at low-cost is becoming pivotal. However, this remains challenging due to expensive metal electrodes and organic hole-transporting materials (OHTMs) typically used in PSCs. By simplifying the device structure, OHTMs-free and noble metal-electrodes-free planar PSCs with the aperture area of 1 cm2 are fabricated with novel NiO@CSs-composite electrodes. The distribution of hole-accepting nickel oxide (NiO) as closely-packed shells on the core carbon spheres (CSs) in the rambutan-like NiO@CSs-composite enhances the photogenerated hole collection efficiency and reduces recombination loss. The small porosity of this composite inhibits the intrusion of the oxygen/moisture through the counter electrode, thus enabling a stable device's efficiency of 11.70% up to 1500 h under 40–60% humidity without encapsulation. The ability to fabricate large-sized planar devices with NiO@CSs-composite electrodes represents a significant step towards the cost-effective and scalable manufacturing with numerous possibilities to choose and optimize the materials, and device's architecture.
The present work consists of a tubular-shaped direct methanol fuel cell (DMFC) that is operated completely passively with methanol solution stored in a central fuel reservoir. The benefit of a tubular-shaped DMFC over a planar-shaped DMFC is the higher instantaneous volumetric power energy density (power/volume) associated with the larger active area provided by the tubular geometry. Membrane electrode assemblies (MEAs) with identical compositions were installed in both tubular and planar-shaped, passive DMFCs and tested with 1, 2, and 3M methanol solutions at room temperature. The peak power density for the tubular DMFC was 19.0mWcm−2 and 24.5mWcm−2 while the peak power density for the planar DMFC was 20.0mWcm−2 and 23.0mWcm−2 with Nafion® 212 and 115 MEAs, respectively. Even though the performance of the fuel cell improved with each increase in methanol concentration, the fuel and energy efficiencies decreased for both the tubular and planar geometries due to increased methanol crossover. The tubular DMFC experienced higher methanol crossover potentially due to a higher static fluid pressure in the anode fuel reservoir (AFR) caused by the vertical orientation of the tubular fuel reservoir. The performance of the tubular DMFC in this work represents an 870% improvement in power density from the previous best, passive, tubular DMFC found in the literature.
Nickel-cobalt-borons are synthesized using a facile and cost-effective reduction method. The effects of Ni/Co molar ratios and crystallinity on its supercapacitive performance are systematically investigated. It was found that nickel-cobalt-borons with the Ni/Co ratio being 2:1 and amorphous structure manifest the optimum specific capacitance of 2226.96 F/g at a current density of 1 A/g and still remain 1879.2 F/g with a high discharge current density of 20 A/g. An asymmetric supercapacitor device (ASC) has been fabricated with nickel-cobalt-borons (Ni-Co-B) as the positive electrode and commercial activated carbon (CAC) as the negative electrode material. The Ni-Co-B//CAC delivers an ultrahigh energy density of 66.40 Wh/kg at a power density of 788.91 W/kg. This ASC remains 85.76% of its initial capacitance even after 5000 charge–discharge cycles. The results demonstrate that amorphous nickel-cobalt-boron material is a promising candidate for energy storage application.
Graphite/LiNi0.4Mn1.6O4 cells assembled with a new reinforced polyvinylidene fluoride (pVDF)–nano crystalline cellulose (NCC) separator and EC–DMC 1 M LiFAP electrolyte with additives were tested by deep charge/discharge cycles at different C-rates and by the FreedomCAR DOE protocol to simulate the dynamic functioning of the batteries in power-assist full hybrid electric vehicles (HEVs). The results of this study evidence the beneficial impact of the pVDF–NCC macroporous membrane with respect to the polypropylene monolayer Celgard®2400 separator on the high C-rate cell performance. The deep charge/discharge of the cell with pVDF–NCC at C/1 effective rate provided 101 W h kg−1 to be compared with 85 W h kg−1 of the cell with Celgard®2400 (the cell weight was considered twice the composite electrode weight of both electrodes). Also hybrid pulse power characterization tests based on the FreedomCAR protocol at 5 C and 10 C demonstrated the superior performance of the cells with pVDF–NCC with respect to that of the cells with Celgard®2400 even if both cells exceed the FreedomCAR goals of power and energy for minimum and maximum power-assist HEV.
Orexins are hypothalamic peptides that play an important role in maintaining wakefulness in mammals. Permanent deficit in orexinergic function is a pathophysiological hallmark of rodent, canine and human narcolepsy. Here we report that in rats, dogs and humans, somnolence is induced by pharmacological blockade of both orexin OX1 and OX2 receptors. When administered orally during the active period of the circadian cycle, a dual antagonist increased, in rats, electrophysiological indices of both non-REM and, particularly, REM sleep, in contrast to GABAA receptor modulators; in dogs, it caused somnolence and increased surrogate markers of REM sleep; and in humans, it caused subjective and objective electrophysiological signs of sleep. No signs of cataplexy were observed, in contrast to the rodent, dog or human narcolepsy syndromes. These results open new perspectives for investigating the role of endogenous orexins in sleep-wake regulation.
Children with attention-deficit/hyperactivity disorder (ADHD) are at greater risk for suicidal ideation and suicide attempts compared to those without ADHD. Increased risk is at least partially attributable to a subset of children with ADHD and comorbid depression or disruptive behavior disorders; however, the early predictors and mechanisms driving increased risk are not well understood. Here, we investigate the contributions of two candidate mechanisms for increased suicidal ideation in children with ADHD: executive function and negative affect. 623 clinically well-characterized, community-recruited children classified by research criteria as ADHD (n = 388) or typically-developing controls (n = 253) participated. Parent-report on the Temperament in Middle Childhood Questionnaire provided a measure of negative affectivity. Children completed laboratory tasks to measure response inhibition and working memory. Suicidal ideation was evaluated by parent report during a semi-structured interview and child responses on the Children’s Depression Inventory. Compared to typically developing controls, children with ADHD had higher rates of suicidal ideation, more negative affect, slower stop signal reaction times, and weaker working memory. Statistical path-model analyses confirmed the hypothesis that weaker working memory in ADHD statistically mediated increased negative affect. Weaker working memory also mediated and increased suicidal ideation in these cross sectional data. Findings were not attributable to comorbid disruptive behavioral disorders. Poor response inhibition did not reliably mediate negative affect or suicidal ideation. Impairment in working memory is an important early risk factor for suicidal ideation in children with ADHD, and may help in identifying children for prevention and early intervention efforts.
Carbon nanotubes (CNTs) have been considered as a potential anode material for next generation Lithium-ion batteries (LIBs) due to their high conductivity, flexibility, surface area, and lithium-ion insertion ability. However, the low mass loading and bulk density of carbon nanomaterials hinder their use in large-scale energy storage because their high specific capacity may not scale up linearly with the thickness of the electrode. To address this issue, a novel three-dimensional (3D) architecture is rationally designed by stacking layers of free-standing CNTs with the increased areal density to 34.9 mg cm−2, which is around three-times higher than that of the state-of-the-art graphitic anodes. Furthermore, a thermal compression process renders the bulk density of the multi-stacked 3D CNTs to be increased by 1.85 g cm−3, which yields an excellent volumetric capacity of 465 mAh cm−3 at 0.5C. Our proposed strategy involving the stacking of 3D CNT based layers and post-thermal compression provides a powerful platform for the utilization of carbon nanomaterials in the advanced LIB technology.
This paper describes an advanced battery pack modeling method for automotive applications. In contrast to the common approach of aggregating hundreds of battery cell models in series and parallel for battery pack representation, a simple yet accurate electrical analogue battery model with constant parameters is used to represent the whole battery pack. The modeling process involves only the external characteristics of the battery pack, thus detailed knowledge of the physical construction of the battery pack or the physical parameters of the battery cells are avoided. Battery experimental tests include an independent pulse charging/discharging cycle test and several performance estimates acquired from the anticipated battery application. This modeling approach is achieved by anticipating the bandwidth of the battery application and then optimizing the bandwidth of the battery pack model with this knowledge. The reported work enables a fast dynamic battery pack simulation with a new level of high fidelity. Although the scope of this work does not include temperature and lifetime effects, it is shown that the form of the model and the parameter extraction procedure can encompass these important improvements. This approach was experimentally verified on a 360 V, 21.3 kWh lithium-ion battery pack operated in a plug-in hybrid electric vehicle.
All-solid-state-batteries (ASSBs) are one of the most promising post-lithium-ion technologies that can increase the specific energy density and safety of secondary lithium batteries. Solid sulfide electrolytes are considered as promising candidates to be used in ASSBs owing to high ionic conductivities. In particular, solid electrolytes in the Li2S − P2S5 binary system have attracted considerable attention as they are composed of low-cost elements and they provide ionic conductivity values comparable to those of liquid electrolytes (>10−4 Scm−1). In this review, the structural properties and synthesis methods of materials in the binary system are summarized. Distinctions in local structures and Li-ion conduction properties between glassy, glass-ceramic, and crystalline materials are highlighted. Possible mechanisms are proposed for the fast ionic conduction observed in glass-ceramics. Important parameters of each synthesis method are suggested and the relationships between structure, synthesis and material properties are discussed. The goals of this review are to provide greater understanding of the state-of-the-art in the field, and to point out the overlooked aspects for application.
Solar Home System (SHS) based rural electrification has experienced a considerable growth in Bangladesh since the start of the Rural Electrification and Renewable Energy Development Project (REREDP) in 2003. The initial target of 50,000 SHS installations in off-grid areas was achieved within 2.5 years, 3 years ahead of schedule. After achieving a revised target of 200,000 SHSs, ahead of schedule in early 2009, a new target of 1 million SHS installations by 2012 was set. The installation of about 0.5 million systems by March 2010 indicates that the current target may well be achieved before the deadline. The size of the SHS market and its impact on the regeneration of the rural economy make it necessary to investigate the quality and reliability of the installed SHSs, if the continued success of the initiative is to be maintained. This paper reports on the findings from a field-based technical appraisal of SHS installations in Bangladesh. Sixty geographically dispersed installation sites were visited. Physical characteristics of the SHSs and their system components were tested to ascertain compliance with and deviations from the approved specifications. Despite the overwhelming success of the REREDP project, the study revealed various shortcomings. Notable among these are: incompatible and sub-optimal component configurations, faulty installations and a lack of effective quality assurance mechanism. The findings are contextualized and the ways to address the identified shortcomings are discussed.
Individuals with mirror touch synaesthesia (MTS) experience touch on their own body when observing others being touched. A recent account proposes that such rare experiences could be linked to impairment in self-other representations. Here we tested participants with MTS on a battery of social cognition tests and found that compared to non-synaesthete controls, the MTS group showed impairment in imitation-inhibition but not in visual perspective taking or theory of mind. Although all of these socio-cognitive abilities rely on the control of self-other representations, they differ as to whether the self, or the other, should be preferentially represented. For imitation-inhibition, representations of the other should be inhibited and self-representations should be enhanced, whereas the opposite is true for visual perspective taking and theory of mind. These findings suggest that MTS is associated with a specific deficit in inhibiting representation of other individuals and shed light on the fractionability of processes underlying typical social cognition.