batterydata/paper-abstracts huggingface dataset:
The consequences of bridge fires and the lack of guidelines on the evaluation of the fire resistance of bridges have triggered a lot of recent research. Most of these studies are based on numerical models and thus need validation by experimental studies. This paper aims to bridge this gap by describing a battery of open air fire tests carried out under an experimental bridge at the Universitat Politècnica de València in Valencia, Spain. The bridge, with a 6m span and a composite deck with two steel I-girders supporting an RC slab, was submitted to four different fire scenarios similar to those of real bridge fires, although smaller in magnitude. Results show that: (a) maximum gas temperatures are reached in the region between the I-girders, (b) as gas and steel temperatures vary significantly along the longitudinal axis of the bridge, it is unrealistic to assume a longitudinally uniform gas or girder temperature (c) temperatures in the bottom flange and the web of the I-girders are very similar and significantly higher than top web temperatures, and (d) the magnitude of the fire load and its position are key factors in the bridge response. This study is of major importance as it enables the validation of the numerical models used in bridge fire engineering and is a crucial step towards the development of a performance-based approach for the design of bridges against fires. The information given will also be useful to those interested in carrying out open air experimental bridge fire tests.
The results of an investigation on the use of a hydrogen diffusion anode (HDE) for electrowinning of lead in chloride medium are reported. Given that lead ions may poison the platinum electrocatalyst of the HDE, the H2 oxidation reaction in the presence of lead ions on a platinum rotating disk electrode (RDE) was studied. Finally, the influence on the lead electric cost of the substitution of the traditionally used O2-dimensionally stable anode (DSA-O2) by an HDE was studied.
Thermal runaway is the main factor contributing to the unsafe behaviors of lithium-ion batteries (LIBs) in practical applications. The application of separators for the thermal shutdown has been proven as an effective approach to protecting LIBs from thermal runaway. In this work, we developed a thermal shutdown separator by coating a thin layer of low-density polyethylene microspheres (PM) onto a commercial porous polypropylene (PP) membrane and investigated the thermal response behaviors of the as-prepared PM/PP separator in LIBs. The structural and thermal analysis results revealed that the coated PM layer had a porous structure, which facilitated the occurrence of normal charge-discharge reactions at ambient temperature, although it could melt completely and fuse together within very short time periods: 3 s at 110 °C and 1 s at 120 °C, to block off the pores of the PP substrate, thereby cutting off the ion transportation between the electrodes and interrupting the battery reaction. Consequently, the PM/PP separator exhibits very similar electrochemical performance to that of a conventional separator at ambient temperature. However, it performs a rapid thermal shutdown at an elevated temperature of ∼110 °C, thus controlling the temperature rise and maintaining the cell in a safe status. Due to its synthetic simplicity and low cost, this separator shows promise for possible application in building safe LIBs.
Vehicle-to-grid (V2G) energy transfer in a smart grid environment opens a new revenue opportunity for electric-drive vehicles (EVs), and might reduce grid operation costs in demand-constrained urban feeders where peak-electricity prices are high. This paper analyses the peak demand energy market for V2G in the urban region of Florianópolis, Brazil. The article describes known V2G-concepts and introduces two different dispatch strategies developed for the Brazilian energy market in the light of new tariff regulations, which are expected to go into effect starting in 2014. It turns out that electric-drive vehicles may be used as a grid-stabilisation strategy, but the announced tariff regulations may lead to a destabilisation if there are too many cars offering their internal storage for V2G grid support. Adequate energy policy strategies must be introduced to avoid the conflicting interests that might stem from the different perspectives of grid operators and EV owners. In contrast to previous analyses, this research assumes the battery degradation as a function of depth of discharge (DOD), which is known for a specific battery.
This paper presents the direct synthesis of highly porous carbons via the carbonization of potassium humate in inert atmosphere without any activation. Carbonization temperature is important for carbon structures and their electrochemical performance in electric double-layer capacitors. The CK800 material derived from potassium humate has a high–specific surface area of 890 m2 g−1 and an ideal average pore size of 2.56 nm. The CK800 material can also deliver a high-specific capacitance of 232 F g−1 (26.1 µF cm−2) at a constant charge/discharge current of 0.5 A g−1. This capacitance is maintained at a value of 114 F g−1 (12.8 µF cm−2) at 30 A g−1. This material also has good cycle stability with over 93.5 % capacitance retention after 5000 cycles when measured in a three-electrode system using 6 M KOH as electrolyte. In this study, the CK800 material is tested in a three-electrode system using 1 M NaHCO3 as electrolyte. Operational voltage in 1 M NaHCO3 aqueous solution could be extended up to 1.3 V.
This work addresses the electrochemical performances of an over-lithiated lithium nickel oxide (Li2NiO2) as a sacrificing positive additive for lithium-ion batteries. Li2NiO2 decomposes along with a crystalline to amorphous phase transition at 3.5V (vs. Li/Li+) in the first charging period, which is far below the charging potential of common positive electrodes (for instance, ca. 4.0V for LiCoO2). The decomposed amorphous phases then deliver a de-lithiation capacity up to >300mAhg−1 in the first charging. The combined feature of easy decomposition and large first de-lithiation capacity demonstrates that Li2NiO2 is a promising positive additive to provide the electric charges/Li+ ions for the charge compensation on negative electrodes. In addition, this over-lithiated lithium nickel oxide delivers a reversible capacity amounting to 70–90mAhg−1 in the continuing cycles, which is an extra capacity to be added to that delivered by main positive electrodes. It is found that the capacity gain (extra capacity) is larger when Li2NiO2 is decomposed at a faster rate due to a smaller charge transfer resistance. This finding suggests that, when Li2NiO2 is used as the sacrificing positive additive, the use of higher current in the first charging is preferred for the capacity gain.
The ability of humans to predict and explain other people’s behaviour by attributing independent mental states such as desires and beliefs to them, is considered to be due to our ability to construct a “Theory of Mind”. Recently, several neuroimaging studies have implicated the medial frontal lobes as playing a critical role in a dedicated “mentalizing” or “Theory of Mind” network in the human brain. In this study we compare the performance of patients with right and left medial prefrontal lobe lesions in theory of mind and in social cognition tasks, with the performance of people with schizophrenia.
A series of Mg2+ doped Li2Na2Ti6O14 in the form of Li2-xMgxNa2Ti6O14 (x=0.0, 0.05, 0.1, 0.15, 2.0) are successfully synthesized via a solid-state method. Phase structure and surface morphology analyses show that all samples maintain high purity and low dose of Mg2+ doping does not change the crystal structure and surface morphology of Li2Na2Ti6O14. According to the Rietveld refinement result, it is known that Mg2+ takes the tetrahedral 8i sites shared with Li+ in the structure. Galvanostatic charge/discharge tests demonstrate that Li1.95Mg0.05Na2Ti6O14 exhibits higher reversible capacity (264.6mAhg−1) and better cycling performance (capacity retention of 82.7% after 50 cycles) than other materials. Even cycled at high current density of 500mAg−1, Li1.95Mg0.05Na2Ti6O14 still provides the specific capacity of 167.4mAg−1 after 100 cycles, indicating that low dose of Mg2+ doping can effectively improve the lithium storage capability of Li2Na2Ti6O14. The enhanced electrochemical properties are contributed to the improved electronic conductivity and ionic diffusion coefficient of Li2Na2Ti6O14 via Mg2+ doping. Besides, the lithiation/delithiation behavior of Li1.95Mg0.05Na2Ti6O14 is also studied by homemade in-situ X-ray diffraction device, which reveals that Li1.95Mg0.05Na2Ti6O14 exhibits high structural and electrochemical reversibility as lithium storage material.
Amino tris(methylene phosphonic acid) (ATMP) is selected as phosphorus and carbon co-source for the synthesis of uniformly nano-sized LiFePO4/C by a quasi-sol–gel method. This strategy using ATMP instead of conventional NH4H2PO4 supplies two advantages: firstly, ATMP in situ chelates Li+ onto its framework and subsequently binds with FeC2O4 in aqueous solution, forming a molecule-scale homogeneous precursor which can obviously improve the purity of LiFePO4. Secondly, the organic carbon contained in ATMP can form uniformly distributed conductive carbon networks among LiFePO4 particles after calcination, which improves the electrical conductivity. The resultant LiFePO4/C with 1.1 wt.% carbon achieves a higher discharge capacity than those of LiFePO4 and LiFePO4/C prepared with inorganic NH4H2PO4. Moreover, core-shell structured LiFePO4/C nanocomposites are also fabricated by further introducing sucrose into the synthesis system. The high-quality carbon shell effectively hinders the LiFePO4 particle growth and aggregation under high-temperature treatment, which further enhances the electrical conductivity and lithium-ion diffusion, resulting in the improved electrochemical performance with excellent cycle stability (the optimum discharge capacity of 158.6mAhg−1 at 0.1C and 138.4mAhg−1 at 2C). The high purity, nanosize and core-shell structure of LiFePO4/C composites yielded by the novel synthesis strategy account for their outstanding electrochemical performance in high-power lithium-ion batteries.
A series of layered Na0.67Lix(Ni0.2Fe0.15Mn0.65)1-xO2+δ (x = 0, 0.1, 0.2 and 0.3) compounds is prepared via a facile oxalate coprecipitation method and a solid-state reaction process, and investigated as the promising positive electrode materials for Na-ion batteries. As the Li content increases, O3 phase and Li2MnO3 gradually grow at the expense of the P2 phase and the particles become smaller and more agglomerated based on X-ray diffraction, scanning electron microscopy and transmission electron microscope results. The optimal Na0.67Li0.2(Ni0.2Fe0.15Mn0.65)0.8O2+δ shows the improved electrochemical performance with a high specific capacity of 151 mAh g−1 and 78% capacity retention over 50 cycles at 0.1 C (15 mA g−1). When tested at 5 C (750 mA g−1) rate, the electrode exhibits a discharge capacity of 68 mAh g−1. The results of electrochemical impedance spectroscopic and ex-situ X-ray diffraction measurements demonstrate that the improved cyclability and rate capability of the Li-substituted cathode can be ascribed to the decreased resistance and the enhanced structure stability in the high voltage of 4.3 V.
Polymer electrolytes based on low molecular weight poly(ethylene glycol)s doped with LiClO4 (0.1–1 mol kg PEG) and containing up to 10 mass% of AlBr3 additive were synthesized and characterized by impedance spectroscopy, FT-IR, DSC and rheological techniques. It has been found that addition of small amount (up to 5 mass%) of AlBr3 increases electrolytes conductivity in comparison with pure PEG–LiClO4 electrolytes for samples containing 1 mol of LiClO4 per kg PEG. Room temperature conductivity as high as 3×10−4 S/cm was measured. For higher AlBr3 concentrations stiffening of the polymer organic electrolyte was observed which results in a decrease in the ionic conductivity. The systematic studies of the interfacial phenomena performed in the symmetrical cell comprising two lithium electrodes separated by PEG–LiClO4–AlBr3 electrolyte allow us to postulate different rate of SEI (solid electrolyte interface) formation and limitation of its growth in the presence of AlBr3 interface thus enhancing the effectiveness of lithium cells.
Integration of renewable energy sources in microgrids can be achieved via demand response programs, which change the electric usage in response to changes in the availability and price of electricity over time. This paper presents a novel control algorithm for joint demand response management and thermal comfort optimization in microgrids equipped with renewable energy sources and energy storage units. The proposed work aims at covering two main gaps in current state-of-the-art demand response programs. The first gap is integrating the objective of matching energy generation and consumption with the occupant behavior and with the objective of guaranteeing thermal comfort of the occupants. The second gap is developing a scalable and robust demand response program. Large-scale nature of the optimization problem and robustness are achieved via a two-level supervisory closed-loop feedback strategy: at the lower level, each building of the microgrid employs a local closed-loop feedback controller that processes only local measurements; at the upper level, a centralized unit supervises and updates the local controllers with the aim of minimizing the aggregate energy cost and thermal discomfort of the microgrid. The effectiveness of the proposed method is validated in a microgrid composed of three buildings, a photovoltaic array, a wind turbine, and an energy storage unit. Comparisons with alternative demand response strategies reveal that the proposed strategy efficiently integrates the renewable sources; energy costs are reduced and at the same time thermal comfort of the occupants is guaranteed. Furthermore, robustness is proved via consistent improvements achieved under heterogeneous conditions (different occupancy schedules and different weather conditions).
A vacuum-annealed La0.6Ca0.4CoO3−x was consecutively oxygenated in air at temperatures decreasing from 800 to 100°C, and its electrocatalytic activities for oxygen reduction and evolution were then measured as a function of the oxygenation temperature. The valence of Co cation, changing between +2 and +3, was found susceptible to annealing either in vacuum or air. The catalytic activities initially decrease monotonically as the oxygenation temperature was decreased from 800 to 300°C, as a result of increasing oxygen content, and then rise abruptly with the oxygen reduction activity reaching a maximum at 200°C and the oxidation activity at 150°C. X-ray photoelectron spectroscopy analysis indicated that the enhancements by the low-temperature oxygenation involved increased OH coverage and less charged cations at surface. The results clearly reveal the importance of the post-calcination annealing process for optimizing the performance of La0.6Ca0.4CoO3−x in air electrode applications.
Severe safety concerns are impeding the large-scale employment of lithium/sodium batteries. Conventional electrolytes are highly flammable and volatile, which may cause catastrophic fires or explosions. Efforts to introduce flame-retardant solvents into the electrolytes have generally resulted in compromised battery performance because those solvents do not suitably passivate carbonaceous anodes. Here we report a salt-concentrated electrolyte design to resolve this dilemma via the spontaneous formation of a robust inorganic passivation film on the anode. We demonstrate that a concentrated electrolyte using a salt and a popular flame-retardant solvent (trimethyl phosphate), without any additives or soft binders, allows stable charge–discharge cycling of both hard-carbon and graphite anodes for more than 1,000 cycles (over one year) with negligible degradation; this performance is comparable or superior to that of conventional flammable carbonate electrolytes. The unusual passivation character of the concentrated electrolyte coupled with its fire-extinguishing property contributes to developing safe and long-lasting batteries, unlocking the limit toward development of much higher energy-density batteries.
In developing high-performance electrode materials for lithium-ion batteries, building kinetically stable graphene–SnO2 anode is appealing yet remains challenging. Here we demonstrate a balanced design of graphene–SnO2 composite, i.e., a flexible nitrogen-doped graphene/SnO2 (NG–SnO2) foam with an integrated macroscale film and interconnected micro-/nano-foam architecture. The combined favorable structure and components improve the Li+ accessibility and electron transmission, while prevent side reactions with the electrolyte and SnO2. Notably, a novel electrochemistry is triggered by the synergistic effect between SnO2 and graphene, i.e., irreversible conversion reaction of SnO2 becomes reversible upon cycling. These efforts lead to an ascending capacity with the increment of >1000mAhg−1. The composite foam can retain more than 81% of its initial capacity to 1678mAhg−1 over cycles of 8.5 months at a rate of 0.1Ag−1, exhibiting kinetically-stable electrochemical performances.
Jim Balcom, the President and Chief Executive Officer of PolyFuel has credited the US Department of Energy (DOE) with providing ‘critical and timely’ support of his company's development efforts, in a programme that has led to significant advances in portable fuel cell technology.
A new positive substrate for high-power nickel/metal-hydride (Ni/MH) battery was designed and prepared based on a nonwoven cloth technique. For the substrate, the amount of plated nickel was reduced to less than half compared with the conventional foam-type substrate, and the manufacturing process was simplified, which lowers the manufacturing cost of the substrate. The sub-C size cylindrical sealed cell using the developed substrate exhibited superior high-rate discharging capability to the cell using the foam-type one in spite of the reduction in the amount of plated nickel due to the characteristic three-dimensional micronetwork structure of the developed substrate. In addition, the prepared cell exhibited a long cycle-life of more than 2000 cycles at 25°C. A hybrid electric vehicle (HEV) mode cycle test consisting of multiple pulse patterns was also performed on the cell at 45°C, and the cell remained more than 85% power of the initial value even after 100,000 cycles (driving distance: ca. 300,000km). The developed micronetwork substrate was revealed to satisfy both high-power output and long cycle-life.
The most efficient first-time invasive treatment, for achieving sinus rhythm, in symptomatic paroxysmal atrial fibrillation has not been established. We aimed to compare percutaneous catheter and video-assisted thoracoscopic pulmonary vein radiofrequency ablation in patients referred for first-time invasive treatment due to symptomatic paroxysmal atrial fibrillation. The primary outcome of interest was the prevalence of atrial fibrillation with and without anti-arrhythmic drugs at 12 months.
The flexible solid-state battery supercapacitor hybrid (SBS) is one of the promising energy storage devices for wearable electronic devices. Surface properties of active materials play important roles on electrolyte/active material interaction and energy storage ability. This work applies nickel cobalt oxide (NiCo2O4) and nickel cobalt oxide@nickel molybdenum oxide (NiCo2O4@NiMoO4) as the active material for SBS. Effects of structure-directing agents (SDA) and substrates on surface properties and energy storage abilities of active materials are investigated. SDA has less influence on active material morphology while Ni foam with higher electrical conductivity is preferable as substrate. The best energy storage ability is obtained for SBS with NiCo2O4@NiMoO4 electrode prepared using ammonium fluoride with capacity of 0.68 mAh/cm2 and the maximum energy density of 70.78 Wh/kg at 3.25 kW/kg. Excellent bending ability for the device with nearly no capacitance decay under 150° bending is attained. Capacitance retention of 80% and Coulombic efficiency of higher than 95% are achieved for SBS measured in 5000 times charging/discharging process. This work firstly relates surface property of active materials to energy storage ability of SBS. It is expected that more efficient active materials and better energy storage ability can be eventually achieved by understanding effects of synthesizing parameters.
Recent advances in microelectronics and integrated circuits, system-on-chip design, wireless communication and intelligent low-power sensors have allowed the realization of a Wireless Body Area Network (WBAN). A WBAN is a collection of low-power, miniaturized, invasive/non-invasive lightweight wireless sensor nodes that monitor the human body functions and the surrounding environment. In addition, it supports a number of innovative and interesting applications such as ubiquitous healthcare, entertainment, interactive gaming, and military applications. In this paper, the fundamental mechanisms of WBAN including architecture and topology, wireless implant communication, low-power Medium Access Control (MAC) and routing protocols are reviewed. A comprehensive study of the proposed technologies for WBAN at Physical (PHY), MAC, and Network layers is presented and many useful solutions are discussed for each layer. Finally, numerous WBAN applications are highlighted.
Core-shell structured ZnS-C nanoparticles are successfully synthesized by a chitosan-assisted hydrothermal method followed by a chemical vapor deposition process using C2H2. The ZnS nanoparticles (c.a. 100–150nm in size) are uniformly coated by a thin carbon shell with a thickness of about 10nm, forming well-dispersed nano-powders. When applied as anode in lithium cells, the synthesized nano-ZnS-C composite exhibits a specific capacity of 565mAhg−1 at 0.1Ag−1 and 363mAhg−1 at 5Ag−1 current density. After 600 cycles at a current density of 0.5Ag−1, the constructed electrode shows over 87% capacity retention, indicating excellent electrochemical performance. The outstanding properties of the obtained nano-ZnS-C can be attributed to the well-defined core-shell nanostructure, in which the nano-sized ZnS core provides short lithium ion diffusion pathways, while the carbon shell allows for a fast electron conduction, and at the same time accommodates the volume changes caused by the lithiation/delithiation of ZnS.
The electrochemical performances of Li3Cu2O4 and Li2NaCu2O4 as cathode materials in lithium coin type batteries have been studied. In Li3Cu2O4, the copper was oxidised to the III level when cycling. The replacement of the lithium by the sodium ions in the octahedral sites in Li2NaCu2O4 might have an effect on the pathway of the lithium ions during the (de)intercalations.