batterydata/paper-abstracts huggingface dataset:
Due to its unique physical and chemical properties, graphene is being considered as a promising material for energy conversion and storage applications. Introduction of functional groups and dopants on/in graphene is a useful strategy for tuning its properties. In order to fully exploit its potential, atomic-level understanding of its interaction with species of importance for such applications is required. We present a DFT study of the interaction of sodium atoms with epoxy-graphene and analyze how this interaction is affected upon doping with boron and nitrogen. We demonstrate how the dopants, combined with oxygen-containing groups alter the reactivity of graphene towards Na. Dopants act as attractors of epoxy groups, enhancing the sodium adsorption on doped oxygen-functionalized graphene when compared to the case of non-doped epoxy-graphene. Furthermore, by considering thermodynamics of the Na interaction with doped epoxy-graphene it has been concluded that such materials are good candidates for Na storage applications. Therefore, we suggest that controlled oxidation of doped carbon materials could lead to the development of advanced anode materials for rechargeable Na-ion batteries.
Objective: Executive functions in activities of daily living (ADL) were investigated in 10 patients with frontal lobe lesions after a mild to severe closed head injury (CHI). Method: The CHI patients were compared to 12 normal controls with a neuropsychological test battery, a script recitation task and a realistic simulation of complex multitask ADL (planning and preparing a meal). Results: Though the CHI patients were significantly slow on one test and subject to interference on an attention test with parametric testing, the groups did not differ on any neuropsychological test with non parametric testing. However, the CHI patients manifested marked anomalies in the meal preparation task. While small sequences of actions were easily produced, large action sets could not be correctly executed. Conclusion: An outstanding deficit in strategic planning and prospective memory appears to be an important underpinning of the impairment of ADL observed in CHI patients with frontal lobe lesions.
An innovative refrigeration system incorporating phase change material (PCM) is proposed to maintain refrigerated trucks at the desired thermal conditions. The advantage of using PCM to maintain low temperatures is that a conventional refrigeration system does not have to be located on-board the vehicle. In addition, the system consumes less energy and produces much lower local greenhouse gas (GHG) emissions. The phase change thermal storage unit (PCTSU) is charged by a refrigeration unit located off the vehicle when stationary. The PCM is discharged and provides cooling when in service. A new PCM with a lower cost than currently available PCMs was developed, suitable for maintaining the refrigerated truck at a temperature of −18°C. The PCM has a melting temperature of −26.7°C and a latent heat of 154.4kJkg−1. A prototype system was constructed and test results proved that the proposed refrigeration system is feasible for mobile transport. An analysis shows that delivery of refrigerated products can be made with a PCM system having a weight comparable to that of an on board conventional refrigeration system with less than half of the energy cost.
A previous study of 10 patients with Broca’s aphasia demonstrated that the advantage for producing the past tense of irregular over regular verbs exhibited by these patients was eliminated when the two sets of past-tense forms were matched for phonological complexity (Bird, Lambon Ralph, Seidenberg, McClelland, & Patterson, 2003). The interpretation given was that a generalised phonological impairment was central to the patients’ language deficits, including their poor performance on regular past tense verbs. The current paper provides further evidence in favour of this hypothesis, on the basis of a detailed analysis of the errors produced by these same 10 patients in reading, repetition, and sentence completion for a large number of regular, irregular, and nonce verbs. The patients’ predominant error types in all tasks and for all verb types were close and distant phonologically related responses. The balance between close and distant errors varied along three continua: the severity of the patient (more distant errors produced by the more severely impaired patients); the difficulty of the task (more distant errors in sentence completion>reading>repetition); the difficulty of the item (more distant errors for novel word forms than real verbs). A position analysis for these phonologically related errors revealed that vowels were most likely to be preserved and that consonant onsets and offsets were equally likely to be incorrect. Critically, the patients’ errors exhibited a strong tendency to simplify the phonological form of the target. These results are consistent with the notion that the patients’ relatively greater difficulty with regular past tenses reflects a phonological impairment that is sensitive to the complexity of spoken forms.
Porous nanoparticles-constructed granule LiMn2O4 spinel was achieved by a solid-state reaction at a relatively low temperature of 600°C, using a highly reactive Mn3O4 as manganese source, prepared by a precipitation-oxidation process. The granule LiMn2O4, well-crystallized with negligible oxygen deficiency, combines the advantages of nano-structured and bulk materials, exhibiting excellent electrochemical performance and a high tap density of 2.05gcm−3. Importantly, its cycling performance, especially at elevated temperatures, compares favorably with that of the doped or surface-coated LiMn2O4 materials reported. Also, it shows superior rate capability and cycling performance to the dispersive nanoparticle LiMn2O4 synthesized under the same conditions. The granule LiMn2O4 exhibits a discharge capacity of 121mAhg−1 at a current rate of 1C (where 1C=148mAg−1), and retains a capacity of 103mAhg−1 at 15C, showing 85% capacity retention. After 200 cycles at 1C and 25°C, it delivers a capacity of 119mAhg−1, retaining 98% of its initial capacity. After 100 cycles at 1C and 55°C, it shows a capacity of 114mAhg−1, preserving 95% of its initial capacity. Due to its excellent electrochemical performance and facile synthesis process adopted, the granule LiMn2O4 can serve as a promising cathode for high-performance Li-ion batteries.
A method of fuel circulation with a fixed amount of fuel was employed to investigate a direct methanol fuel cell (DMFC) stack that was built with metal foam flow fields for the air and fuel flows. The stack power output increases significantly with environmental temperature from 20 to 40°C. The average peak power per cell at 40°C is 26mWcm−2 per cell. The average discharge voltage per cell at peak power does not change with temperature but remains at 0.3V. The energy output of the stack was determined at constant current or constant voltage with a fixed amount of methanol to feed the anode of the stack until the fuel was consumed. The results by constant current discharge show that at higher temperature the stack has remarkably higher energy output; while at the same temperature only a suitable magnitude of discharge current can achieve the highest energy output. The results by constant voltage discharge show that the Faradic efficiency is 86%, and the energy efficiency is 17% at 30°C.
In this article, a new simulative approach that can determine ageing inhomogeneities in lithium-ion battery systems is outlined. The proposed method is based on a thermal electric ageing model of an entire battery system and the Monte Carlo Method. This method considers temperature inhomogeneities caused by active cooling within the battery system as well as cell spread and ageing spread caused by tolerances in the cell production. Each cell in the battery system model is represented by its own thermal electric cell model, having an initial capacity, initial internal resistance, ageing rate and thermal connection to the cooling system. In the experimental part of this research work, a battery system consisting of 96 lithium-ion cells based on the LiFePO4-technology was tested to investigate the capacity fade during a cycle life test. The results show that discrepancies in cells ageing within the battery system are a consequence of cell-to-cell spread and different loading of the cells, caused by temperature and SoC inhomogeneities within the battery system. Furthermore, the article will evince the gain of accuracy by using a battery system instead of a previous single cell approach for life prediction.
Lithium-ion hybrid supercapacitors (LIHSs), also called Li-ion capacitors, are electrochemical energy storage devices that combining the advantages of high power density of supercapacitor and high energy density of Li-ion battery. However, high power density and long cycle life are still challenges for the current LIHSs due to the imbalance of charge-storage capacity and electrode kinetics between capacitor-type cathode and battery-type anode. Therefore, great efforts have been made on designing novel cathode materials with high storage capacity and anode material with enhanced kinetic behavior for LIHSs. With unique two-dimensional form and numerous appealing properties, for the past several years, the rational designed graphene and its composites materials exhibit greatly improved electrochemical performance as cathode or anode for LIHSs. Here, we summarized and discussed the latest advances of the state-of-art graphene-based materials for LIHSs applications. The major roles of graphene are highlighted as (1) a superior active material, (2) ultrathin 2D flexible support to remedy the sluggish reaction of the metal compound anode, and (3) good 2D building blocks for constructing macroscopic 3D porous carbon/graphene hybrids. In addition, some high performance aqueous LIHSs using graphene as electrode were also summarized. Finally, the perspectives and challenges are also proposed for further development of more advanced graphene-based LIHSs.
A thermodynamic analysis is presented for an energy storage system without combustion and including thermal recuperation (adiabatic compressed air energy strong (CAES)). The storage volume is optimized and a system layout with thermal storage (TES) and variable configuration is designed. The proposed system is simulated in order to have a first estimate of its energy recovery efficiency.
The wool carder bee, Anthidium manicatum, is the most widely distributed unmanaged bee in the world. It was unintentionally introduced to North America in the late 1960s from Europe, and subsequently, into South America, New Zealand and the Canary Islands. We provide information on the local distribution, seasonal abundance and sex ratio of A. manicatum from samples collected in an intensive two-year survey across Utah, USA. Anthidium manicatum was detected in 10 of the 29 Utah counties, largely in urban and suburban settings. Combining presence-only and MaxEnt background data from literature, museum databases and new records from Utah, we constructed three species distribution models to examine the potential distribution of A. manicatum in its native Eurasian range as well as invaded ranges of North and South America. The A. manicatum model based on locality and background data from the species’ native range predicted 50% of the invasive records associated with high habitat suitability (HS ≥ 0.90). The invasive North American model predicted a much broader distribution of A. manicatum (214% increase); whereas, the South American model predicted a narrower distribution (88% decrease). The poor predictive power of the latter model in estimating suitable habitats in the invasive South American range of A. manicatum suggests that the bee may still be limited by the bioclimatic constraints associated with a novel environment. Estimates of niche similarity (D) between the native and invasive models find that the North America bioclimatic niche is more similar to the bioclimatic niche of the native model (D = 0.78), whereas the bioclimatic niche of the South America invasion is relatively dissimilar (D = 0.69). We discuss the naturalization of A. manicatum in North America, possibly through punctuated dispersal, the probability of suitable habitats across the globe and the synanthropy exhibited by this invasive species.
Vanadium redox flow batteries (VRBs) are very competitive for large-capacity energy storage in power grids and in smart buildings due to low maintenance costs, high design flexibility, and long cycle life. Thermal hydraulic modeling of VRB energy storage systems is an important issue and temperature has remarkable impacts on the battery efficiency, the lifetime of material and the stability of the electrolytes. In this paper, a lumped model including auxiliary pump effect is developed to investigate the VRB temperature responses under different operating and surrounding environmental conditions. The impact of electrolyte flow rate and temperature on the battery electrical characteristics and efficiencies are also investigated. A one kilowatt VRB system is selected to conduct numerical simulations. The thermal hydraulic model is benchmarked with experimental data and good agreement is found. Simulation results show that pump power is sensitive to hydraulic design and flow rates. The temperature in the stack and tanks rises up about 10 °C under normal operating conditions for the stack design and electrolyte volume selected. An optimal flow rate of around 90 cm3 s−1 is obtained for the proposed battery configuration to maximize battery efficiency. The models developed in this paper can also be used for the development of a battery control strategy to achieve satisfactory thermal hydraulic performance and maximize energy efficiency.
Influence of the conductive additive loading on the anode performance of Li-ion battery was investigated for the coated anode where graphitized mesophase carbon fiber (MCF) was used as an active material, and loaded with natural graphite (NG), acetylene black (AB) or Ketjen black (KB). Incorporation of the conductive additive was quite effective to improve not only the cycle life, but also the rate of the electrochemical reaction. In addition, we found that the initial irreversible charging capacity (IICC) of MCF was suppressed to a great extent. The effectiveness was dependent on the kind of material loaded. On the other hand, making a homogeneous slurry for coating was found to be a key factor for the performance improvement. The most preferable choice of the preparation condition gave rise to a dramatic improvement. In contrast to these advantages, the carbon blacks showed a large IICC inherent to the materials which is an issue to be solved for actual use.
Supercooling is an undesired property of phase change materials due to the poorly predictable occurrence of crystallization during cooling. For such situations, the stored latent heat cannot be recovered which can be an issue for temperature-controlled applications. This review illustrates the techniques used for triggering crystallization in phase change materials having a supercooling property. The development of triggering devices should constitute a breakthrough for heat on demand applications, as heat can be released even when the temperature drops far below the liquidus temperature. Several techniques appear to be promising for nucleation triggering. They have been classified into two categories: passive (reduction of supercooling) or active (triggering of crystallization on demand) devices. They were accurately investigated for water freezing for: meteorological comprehension, food preservation or the pharmaceutical industry. In this paper, several nucleating agents (passive) have been explored, and most of them, added by 1 wt%, can decrease the supercooling degree by more than 90%. In addition, the heat would be immediately released on demand from a supercooled material by the use of seeding or electrofreezing (active methods). Solidification can also be externally triggered by the application of high pressure or ultrasonic waves (active). In addition to the analysis of the efficiency of the different techniques in terms of supercooling reduction, this review also discusses the solidification process at a microscopic scale.
Batteries that can be directly recharged by light would offer a new approach to balancing the unpredictable energy surpluses and deficits associated with solar energy. Here, we present a new aqueous zinc-ion battery (photo-ZIB) that can directly harvest sunlight to recharge without the need for external solar cells. The light charging process is driven by photo-active cathodes consisting of a mixture of vanadium oxide (V2O5) nanofibers, poly(3-hexylthiophene-2,5-diyl) and reduced graphene oxide, which provide the desired charge separation and storage mechanism. This process is studied using photodetectors, transient absorption spectroscopy and electrochemical analysis in dark and light conditions. The V2O5 cathodes have gravimetric capacities of ∼190 mA h g−1 and ∼370 mA h g−1 in dark and illuminated conditions respectively and photo-conversion efficiencies of ∼1.2%. Finally, we demonstrate a fully functional photo-ZIB with a ∼64 cm2 optical window in pouch cell format.
Cobalt selenide@reduced graphene oxide (CoSe2@rGO) nanohybrid was successfully synthesized by a facile one-pot hydrothermal method and the electrochemical performance of the nanohybrid was evaluated for supercapacitor applications. The CoSe2@rGO nanohybrid show superior electrochemical performance in terms of the specific capacitance (449 F g−1 at 2 mV s−1, 219 F g−1 at 0.5 A g−1) and enhanced cyclic stability (91.3% capacitance retention for 5000 cycles) relative to pure CoSe2 (196 F g−1 at 2 mV s−1, 99 F g−1 at 0.5 A g−1). Such a highly improved specific capacitance found in the CoSe2@rGO nanohybrid electrode is mainly attributed to the nanosized CoSe2 grains with perfect redox property, more electro-active sites induced by synergetic effect at the interface of CoSe2 and rGO, and high specific area of rGO nanosheets. Besides, with the combination of rGO, the electrical conductivity of the CoSe2@rGO nanohybrid is highly enhanced, the ion/electron diffusion path is also reduced leading to faster charge transport during charging/discharging process with an improved cyclic stability.
In this paper, a simple but innovative bi-directional energy conversion system is developed, utilizing supercapacitor as energy source to drive an electric scooter, as well as to recover braking energy on demand. Supercapacitor is superior to battery at high load as the latter is susceptible to aging and significant heat loss under this condition, leading to sometimes serious issues such as shortened lifecycle. The system consists of a microprocessor based vehicle controller (integrating an embedded regenerative braking controller), a 300W Permanent Magnet (PM) DC motor, two low-power DC–DC converters to form a higher power DC–DC converter pack, a motor controller, a supercapacitor bank and a capacitor cell balancing sub-system. To characterize system performance, a dedicated test rig is built and the system is broken down into three stages with input and output variables of each stage being evaluated systematically in three representative cases. The experimental results show overall effectiveness of such system. Operating conditions where high efficiency reside are therefore able to be determined to gain insight into a complex system.
Platinum-free (Pt-free) counter electrodes (CEs) can reduce the cost of dye-sensitized solar cells (DSCs). In this study, a general strategy is proposed to construct Pt-free CEs, namely direct growth of electrocatalytic active nanostructures (metal sulfide, etc.) on conductive substrates via low temperature solution routes. As an implementation, nickel sulfide (NiS) nanoarray film composed of interconnected nanoplatelets is successfully fabricated by a two-step solution route. The as-grown NiS nanoarray film follows the sulfurization process in a thiourea aqueous solution from the precursor of hydrothermally deposited Ni(OH)2 nanoplatelet arrays on FTO substrates. When applied as a Pt-free CE in DSCs, a maximum power conversion efficiency of 7.10% is achieved, comparable to that of Pt CE (7.35%).
Across the entire Greek territory one may encounter several remote consumers that could cover their needs on the basis of PV-based stand-alone applications exploiting the high quality local solar potential. In this context, optimum sizing of such installations also involves investigation of the optimum panels' tilt angle, which opposite to grid-connected applications is required to provide year-round energy autonomy rather than maximization of the annual energy yield. Considering the above, investigation of the optimum panels' tilt angle for stand-alone applications is the aim of the specific study, in both theoretical and experimental terms. Theoretical investigation is based on the validation of the assumption that the optimum angle for such applications coincides with the angle that provides maximum exploitation of solar potential during winter months, while following, the optimum angle determined in the area of 60° is also experimentally validated with the conduction of long-term winter measurements for the area of Athens.
Herein we present the preparation of novel multifunctional metallic nickel/oxide (Ni/NiO) hybrid nanomembranes with rough and undulating surface morphologies, by a physical deposition method combined with chemical etching and thermal oxidation. Benefiting from the advantages of intrinsic architecture and electrochemical catalysis of metallic nickel, the anodes can be discharged and charged at an ultrahigh rate of ~115C (1C=718mAg−1) if only the mass of NiO is taken into calculation or 60C if the total mass of Ni/NiO nanomembranes is considered. To our knowledge, this is the best reported rate performance for NiO-based anodes in Li-ion batteries to date. Furthermore, excellent cycling stability is also demonstrated.
We propose a high-temperature, rechargeable metal-air battery that relies on Ti or Zr metal as the anode and the shuttling of oxygen anions between the cathode and the anode through a solid-oxide ion-conducting electrolyte. The cathode has much in common with solid-oxide fuel cells. Key in the proposed battery is the use of Ti or Zr as the anode as these metals are unique in their ability to dissolve oxygen up to concentrations of 33% with minimal structural and volumetric changes. First-principles statistical mechanics calculations predict open circuit voltages around 2.5 V, substantially larger than the open circuit voltage of high-temperature solid-oxide fuel cells. The calculations predict the stability of TiO and ZrO monoxides along with TiO x and ZrO x (with x as high as ½) solid solutions. These suboxide phases are all predicted to be metallic, indicating that electron transport in the anodes will not be rate limiting. The oxygen diffusion coefficients in the Ti and Zr suboxides at high temperature (∼700–800 °C) are predicted to be comparable to that of Li ions in intercalation compounds. These properties suggest theoretical capacities as high as 840 mAh g−1 and 500 mAh g−1 for Ti and Zr based metal-air batteries respectively.