batterydata/paper-abstracts huggingface dataset:
In this work, a novel aqueous rechargeable battery Zn/LiCl-ZnCl2/LiFePO4 has been developed. The electrochemical performance of olivine LiFePO4 positive electrode has been investigated in the structure of this battery. Along with a high (about 100%) coulombic efficiency, this electrode exhibited enhanced cycling performance at various current densities up to 60C with the average operation voltage 1.2V. A capacity of 92mAhg−1 was achieved over 400 cycles at a cycling rate 6C, and exhibited a superior rate capability with the capacities of 72mAhg−1 at 30C and 45mAhg−1 at 60C, respectively. The battery temperature tolerance was first investigated, and it demonstrated a very stable cycling at a wide temperature range from −10°C to 50°C. A cylindrical battery with the capacity of 150mAh was first designed using proposed configuration and successfully operated under 54mA with high efficiency and capacity retention. Zn/LiFePO4 battery offers an exceptionally safe, low cost, long cycling life, and high energy and power density energy storage for large-scale applications.
The electrochemical performance of RGO-Co(mqph) electrocatalyst for Li–air batteries with hybrid electrolyte was investigated. The RGO-Co(mqph) showed high onset potential (−0.09 V vs. Ag/AgCl) under oxygen condition in the rotating disk electrode system for oxygen reduction reaction, which was higher than that of RGO (−0.17 V vs. Ag/AgCl). Furthermore, the ORR mechanism of RGO-Co(mqph) showed 3.52 electron pathway. On the other hand, the RGO only exhibited the electron transfer number of 2.22 for ORR. Moreover, the electrochemical performance of Li–air batteries with hybrid electrolyte showed that the RGO-Co(mqph) provided good discharge performance and cycle performance. It was thus considered that the Co(mqph) strongly affected ORR activity for cathode electrode. This was ascribed to synergic effect due to combination between RGO and Co(mqph).
The rate capacity especially the high rate discharge performance is another important aspect for the application of Mn-based spinel cathodes for EV/HEV power sources besides the cycling performance that is now intensively investigated. In this paper, spinel materials differing in chemical composition and thermal processing history were investigated by discharging at constant current rates from C/10 to 4C at ambient temperature. It was found that the high-rate discharge capability of Mn-based spinels is very excellent if prepared at temperatures below 850°C, no matter cation doping or not. In contrast, spinels synthesized over 950°C showed much poorer high rate performance, and some kinds of impurities were proposed to be responsible for the deteriorated behavior. Annealing at lower temperatures was found to be useful for the significant improvement of the high rate discharge capability of Mn spinels.
CuO/graphene composite is synthesized from CuO and graphene oxide sheets following reduced by hydrazine vapor. As the electrode material for lithium-ion batteries, CuO nanoparticles with sizes of about 30nm homogeneously locate on graphene sheets, and act as spacers to effectively prevent the agglomeration of graphene sheets, keeping their high active surface. In turn, the graphene sheets with good electrical conductivity server as a conducting network for fast electron transfer between the active materials and charge collector, as well as buffered spaces to accommodate the volume expansion/contraction during discharge/charge process. The synergetic effect is beneficial for the electrochemical performances of CuO/graphene composite, such as improved initial coulombic efficiency (68.7%) and reversible capacity of 583.5mAhg−1 with 75.5% retention of the reversible capacity after 50 cycles.
New implantable medical devices and applications are being developed at a rapid rate. Many of these applications have higher power and/or energy requirements than existing applications. These needs will drive the development of new primary lithium chemistries and the implementation of rechargeable lithium-ion technology.
In solid-state alkaline fuel cells (SAFCs), water is generated at the anode and is reacted at the cathode; as such, flooding occurs much more easily at the anode than it does in proton-exchange membrane fuel cells (PEMFCs). Anode flooding is a reason for the low performance of SAFCs, and so it is important that this flooding phenomenon is mitigated. In this study, we control water transport to suppress anode flooding. We do this through two approaches: changing the thickness of the anion exchange membrane (AEM) and changing the anode flow rate. Among two AEMs with two different thicknesses (27 μm and 6 μm) prepared, thinner AEM shows improved fuel cell performance. Increasing the anode flow rate also improved the performance of SAFCs. To find out what caused this, the water transport inside the membrane electrode assembly (MEA) was analyzed. The flooding region was estimated using calculated relative humidity at anode outlet. On the basis of our experimental and calculation approaches, flooding can be suppressed by using thin AEMs and increasing the anode flow rate.
ABSTRACT This paper reviews the experience at Jaguar Land Rover (JLR) of developing cooling system performance sign-off criteria for hybrid powertrain vehicles. The paper explores customer expectations for electric vehicle mode operation in extreme hot and cold environments and describes a process to assist in determining the upper and lower ambient temperature thresholds to ensure customer satisfaction. A method to assist in the development of new transient thermal sign-off drive cycles for hybrid power trains is proposed, together with examples of how this can be applied to typical hybrid driving scenarios. The role of CAE methods in this process and examples of the key considerations are also discussed. Example test results are reviewed which show the extent to which the new hybrid cooling sign-off criteria developed at JLR has achieved its objectives.
A model based non-linear optimisation approach is proposed to obtain the optimal charging current and electrolyte flow rate trajectories (as functions of time) for a vanadium redox flow battery. The optimisation objective is formulated to minimise the total energy consumption of the battery and pumping system. Three operational constraints are addressed by the proposed optimisation: firstly, the input current and electrolyte flow rate are maintained to be within the limits of the power and hydraulic systems, respectively; secondly, charging of battery to a predefined SOC target within a given time frame is achieved; finally, the flow rate is properly constrained to avoid oxygen and hydrogen evolution. Two case studies were conducted under different time limit constraints. The optimisation results are compared with the existing approaches. It has been found that the proposed approach successfully regulated battery SOC to reach target with increased overall system efficiency.
An advanced electrode for high-performance electrochemical capacitors has been designed by growing ultrathin mesoporous Co3O4 nanosheet arrays on the Ni foam support. This unique 3D electrode manifests exceptional supercapacitive performance with ultrahigh specific capacitance at high current densities and excellent cycling stability.
o-Quinones are formed metabolically from natural and synthetic estrogens as well as upon exposure to polycyclic aromatic hydrocarbons (PAH) and contribute to estrogen and PAH carcinogenesis by genotoxic mechanisms. These mechanisms include the production of reactive oxygen species to produce DNA strand breaks and oxidatively damaged nucleobases; and the formation of covalent depurinating and stable DNA adducts. Unrepaired DNA-lesions can lead to mutation in critical growth control genes and cellular transformation. The genotoxicity of the o-quinones is exacerbated by nuclear translocation of estrogen o-quinones by the estrogen receptor and by the nuclear translocation of PAH o-quinones by the aryl hydrocarbon receptor. The properties of o-quinones, their formation and detoxication mechanisms, quinone-mediated DNA lesions and their mutagenic properties support an important role in hormonal and chemical carcinogenesis.
This study investigates aging in LiFePO4/mesocarbon microbead graphite cells that have been subjected to either a synthetic hybrid drive cycle or calendar aging, at 22°C. The investigation involves detailed examination and comparison of harvested fresh and aged electrodes. The electrode properties are determined using a physics-based electrochemical impedance spectroscopy (EIS) model that is fitted to three-electrode EIS measurements, with input from measured electrode capacity and scanning electrode microscopy (SEM). Results from the model fitting provide a detailed insight to the electrode degradation and is put into context with the behavior of the full cell aging. It was established that calendar aging has negligible effect on cell impedance, while cycle aging increases the impedance mainly due to structural changes in the LiFePO4 porous electrode and electrolyte decomposition products on both electrodes. Further, full-cell capacity fade is mainly a consequence of cyclable lithium loss caused by electrolyte decomposition.
Consumer electronics (CE) and electric vehicles (EVs) associated with renewable and sustainable energy have been rapidly changing human lifestyles and transportation habits since 1990s. These active innovations have resulted in a large amount of spent lithium-ion batteries (LiBs) in China. At least two problems are declining the sustainability of production and final disposal of LiBs: one is potential environmental and health risk, and the other is that more and more valuable resources are being stored in spent LiBs without appropriate recycling. We found that a lack of effective regulation, collection systems and recycling technologies are major barriers and challenges to solve the problems. And in order to develop a comprehensive management scheme for this waste stream in China, we proposed a three-pronged approach: (1) new regulation or policy is quite a necessity to deal with the challenges unique to spent LiBs recycling; (2) collection systems for CE and EV batteries can be substantially established based upon past experience of general e-waste management and extended producer responsibility, respectively; and (3) more emphasis needs to be placed on new technology for spent LiBs recycling, to tackle the large quantities of stored spent LiBs.
In our endeavor to improve overall properties of the La–Mg–Ni–Co type alloys, RE0.93Mg0.07Ni2.96Co0.60Mn0.37Al0.17 hydrogen storage electrode alloy with low magnesium content was obtained by inductive melting. The phase structure and electrochemical characteristics of the alloy were investigated by XRD and electrochemical measurement. The results indicate that RE0.93Mg0.07Ni2.96Co0.60 Mn0.37Al0.17 alloy has multi-phase microstructure containing the CaCu5 structure of LaNi5 phase as matrix phase and a little of LaNi3 phase as the secondary phase. The maximum discharge capacity of RE0.93Mg0.07Ni2.96Co0.60Mn0.37Al0.17 alloy reaches 359mAh/g, which is 7.2% higher than that of commercial AB5 alloy electrode. The discharge capacity of RE0.93Mg0.07Ni2.96Co0.60Mn0.37Al0.17 alloy electrode at 233K is up to 147mAh/g, which is 308.3% higher than that of commercial AB5 alloy electrode. Meanwhile, the discharge capacity of RE0.93Mg0.07Ni2.96Co0.60Mn0.37Al0.17 alloy can reach 92.7% of commercial AB5 alloy after 100charge/discharge cycles.
Polyoxometalates (POMs) are a kind of metal oxide nanoclusters with excellent electrical properties, which have proved to be an excellent candidate for electrochromism (EC) materials. In this paper, we present a better performance POMs-based EC material on the TiO2 substrate through adjusting the structure of the Well-Dawson type POMs with the electrodeposition method, which can overcome the high cost of the traditional methods such as vacuum evaporation or sputtering. The performance of the EC smart windows was fully tested. The maximum optical contrast for the K10[P2W17O61]·20H2O (P2W17)-based EC smart window is 93.1% at the wavelength of 620nm and for the K6[P2W18O62]·14H2O (P2W18)-based EC smart window is 48.7% at 646nm. The coloration time extracted for a 90% transmittance for the P2W17-based EC smart window is 0.9s and for the P2W18-based smart window is 0.97s; the coloration efficiency for the P2W17-based EC smart window is 205.3cm2 C−1 and the P2W18-based smart window is 176.8cm2 C−1. Both of the P2W17- and P2W18-based EC smart windows have the feature of remarkable durability over 1000 cycles. The P2W17-based smart window has larger optical contrast and higher coloration efficiency than the P2W18-based smart window. More significantly, the near-infrared behavior of the P2W17 under different applied potentials was recorded for the first time by using the smart window. We believe the performance of the P2W17-based smart window is the state-of-the-art among the POMs-based EC smart windows.
Nanostructured nickel hydroxide thin films are synthesized via a simple chemical bath deposition (CBD) method using nickel nitrate Ni(NO3)2 as the starting material. The deposition process is based on the thermal decomposition of ammonia-complexed nickel ions at 333K. The structural, surface morphological, optical, electrical and electrochemical properties of the films are examined. The nanocrystalline “β” phase of Ni(OH)2 is confirmed by the X-ray diffraction analysis. Scanning electron microscopy reveals a macroporous and interconnected honeycomb-like morphology. Optical absorption studies show that “β-Ni(OH)2” has a wide optical band-gap of 3.95eV. The negative temperature coefficient of the electrical resistance of “β-Ni(OH)2”, is attributed to the semiconducting nature of the material. The electrochemical properties of “β-Ni(OH)2” in KOH electrolyte are examined by cyclic voltammetric (CV) measurements. The scan-rate dependent voltammograms demonstrate pseudocapacitive behaviour when “β-Ni(OH)2” is employed as a working electrode in a three-electrode electrochemical cell containing 2M KOH electrolyte with a platinum counter electrode and a saturated calomel reference electrodes. A specific capacitance of ∼398×103 Fkg−1 is obtained.
Three kinds of surface modifications were carried out on LiNi1/2Mn3/2O4 thin-films to improve the charge and discharge characteristics of LiNi1/2Mn3/2O4 positive electrodes. Among them, Zr(OBu)4/poly(methyl methacrylate) (PMMA)-treated LiNi1/2Mn3/2O4 thin-film electrodes showed charge and discharge efficiency of 80–84% in the first cycle, which was much higher than that for an untreated LiNi1/2Mn3/2O4 thin-film electrode (73%). The values of the charge and discharge efficiency were still higher than that for an untreated electrode after the 30th cycle. The charge and discharge curves gave two plateaus at around 4.72 and 4.76V, which were very similar to those for the untreated electrode. Ac impedance spectroscopy revealed that the surface film resistance should not increase by Zr(OBu)4/PMMA treatment. XPS measurements suggest that a composite layer should be formed on a LiNi1/2Mn3/2O4 thin-film electrode from PMMA and Zr(OBu)4-derived compounds introducing an electrolyte. This composite layer was lithium-ion conductive, and was sustainable enough to suppress subsequent decomposition of an electrolyte at potentials as high as 4.7V.
Lithium-sulfur batteries show great promise among future battery technologies, but their cycle life is mainly restricted by the shuttling effect of soluble lithium polysulfides (LiPSs). The catalytic conversion of LiPSs appears to be a fundamental way of suppressing this. The highly conductive metal nitrides show great potentials as high-performance catalysts, but the presence of a thin surface oxidation layer, which is normal for nanomaterials, restrains the surface electron transfer and catalytic activity. In this study, we demonstrate that the doping of the oxidation layer is an ideal solution to reviving and enhancing the catalytic activity of nitrides. As a proof of concept, sulfur-doping of a titanium nitride (TiN) oxidation layer is presented here, and the TiS bonds formed are responsible for transmitting electrons from the conductive TiN matrix thus guaranteeing a high catalytic activity. Interfacing of TiS with TiO bonds at the atomic level helps realize strong trapping and fast conversion of LiPSs simultaneously. As a result, the specific capacity, rate performance, and cyclic stability are all greatly improved by the interlayer composed of sulfur-doped TiN and graphenes, which indicates a practical avenue for building high performance lithium-sulfur batteries.
The thin films of carambola-like γ-MnO2 nanoflakes with about 20nm in thickness and at least 200nm in width were prepared on nickel sheets by combination of potentiostatic and cyclic voltammetric electrodeposition techniques. The as-prepared MnO2 nanomaterials, which were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), were used as the active material of the positive electrode for primary alkaline Zn/MnO2 batteries and electrochemical supercapacitors. Electrochemical measurements showed that the MnO2 nanoflake films displayed high potential plateau (around 1.0V versus Zn) in primary Zn/MnO2 batteries at the discharge current density of 500mAg−1 and high specific capacitance of 240Fg−1 at the current density of 1mAcm−2. This indicated the potential application of carambola-like γ-MnO2 nanoflakes in high-power batteries and electrochemical supercapacitors. The growth process for the one- and three-dimensional nanostructured MnO2 was discussed on the basis of potentiostatic and cyclic voltammetric techniques. The present synthesis method can be extended to the preparation of other nanostructured metal-oxide films.
Titanium nitride nanoparticles (TiN NPs) are proposed as a novel catalyst towards the V(II)/V(III) redox pair for the negative electrode in vanadium redox flow batteries (VRFB). Electrochemical properties of TiN NPs were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results show that TiN NPs demonstrate better electrochemical activity and reversibility for the processes of V(II)/V(III) redox couples as compared with the graphite NPs. TiN NPs facilitate the charge transfer in the V(II)/V(III) redox reaction. Performance of a VRFB using a TiN NPs coated carbon paper as a negative electrode is much higher than that of a VRFB with a raw carbon paper electrode. The columbic efficiency (CE), the voltage efficiency (VE) and the energy efficiency (EE) of the VRFB single cell at charge-discharge current density of 30mA/cm2 are 91.74%, 89.11% and 81.74%, respectively. During a 50 charge-discharge cycles test, the CE values of VRFB with TiN NPs consistently remain higher than 90%.
Mn3O4/Ni(OH)2 nanocomposites are simply synthesized by a hydrothermal reaction between MnCl2 .4H2O, NiCl2.6H2O and NaOH at 200°C. Compared with the individual Ni(OH)2 and Mn3O4 prepared under the same conditions, the Mn3O4/Ni(OH)2 composite hydrothermally treated for 5h achieves excellent specific capacitance (707Fg−1 at 1Ag−1 in 1M KOH electrolyte) and remarkable long-term cycling stability (retaining a capacitance retention of 89% after 2000 cycles at 2Ag−1). Meanwhile, the asymmetric supercapacitor constructed by the Mn3O4/Ni(OH)2 composite and active carbon delivers an energy density of 17.8Whkg−1 at a power density of 162Wkg−1. The outstanding performance is attributable to the synergistic compositing effect of Mn3O4 and Ni(OH)2, yielding not only the mutual doping of Mn3+ in Ni(OH)2 and Ni2+ in Mn3O4 to improve the electronic conductivity of the Mn3O4/Ni(OH)2 composite but also the suitable mesoporous structure for electrolyte transfer. Thus the Mn3O4/Ni(OH)2 composites will be alternative candidates as practical electrode materials for pseudocapacitors.
The prevalence of self-reported shoulder pain in the UK has been estimated at 16%. This has been linked with significant sleep disturbance. It is possible that this relationship is bidirectional, with both symptoms capable of causing the other. Within the field of sleep monitoring, there is a requirement for a mobile and unobtrusive device capable of monitoring sleep posture and quality. This study investigates the feasibility of a wearable sleep system (WSS) in accurately detecting sleeping posture and physical activity.
Computational techniques, such as Quantitative Structure-Property Relationship (QSPR) modeling, are very useful in predicting physicochemical properties of various chemicals. Building QSPR models requires calculating molecular descriptors and the proper choice of the geometry optimization method, which will be dedicated to specific structure of tested compounds. Herein, we examine the influence of the ionic liquids’ (ILs) geometry optimization methods on the predictive ability of QSPR models by comparing three models. The models were developed based on the same experimental data on density collected for 66 ionic liquids, but with employing molecular descriptors calculated from molecular geometries optimized at three different levels of the theory, namely: (1) semi-empirical (PM7), (2) ab initio (HF/6-311+G*) and (3) density functional theory (B3LYP/6-311+G*). The model in which the descriptors were calculated by using ab initio HF/6-311+G* method indicated the best predictivity capabilities (
Diffusion coefficients of the vanadium ions across Nafion 115 (Dupont) in a vanadium redox flow battery (VRFB) are measured and found to be in the order of V2+ >VO2+ >VO2 + >V3+. It is found that both in self-discharge process and charge–discharge cycles, the concentration difference of vanadium ions between the positive electrolyte (+ve) and negative electrolyte (−ve) is the main reason causing the transfer of vanadium ions across the membrane. In self-discharge process, the transfer of water includes the transfer of vanadium ions with the bound water and the corresponding transfer of protons with the dragged water to balance the charges, and the transfer of water driven by osmosis. In this case, about 75% of the net transfer of water is caused by osmosis. In charge–discharge cycles, except those as mentioned in the case of self-discharge, the transfer of protons with the dragged water across the membrane during the electrode reaction for the formation of internal electric circuit plays the key role in the water transfer. But in the long-term cycles of charge–discharge, the net transfer of water towards +ve is caused by the transfer of vanadium ions with the bound water and the transfer of water driven by osmosis.
Engineering technology is evolving rapidly in the Information Age, much faster than institutions of learning can upgrade their programs and syllabi. India has developed more engineering programs that dwell on mathematical analysis, theory and an understanding of the science rather than engineering technology programs which focus on application of science to solve real-world problems. Industries rely on innovation which is all about making incremental modifications to existing solutions with the intention of adding value or improving the efficiency. Thus there is a fundamental disconnect in the expectation of industry from graduating students and the focus of engineering programs. In this paper, we will consider the aspect of industry-readiness of graduating engineers, focusing on three areas of engineering, namely, electronics and communication engineering, Electrical Engineering, and computer science. The objective of the paper is to identify the gaps and suggest ways to fill this gap.