batterydata/paper-abstracts huggingface dataset:
Variations in cell properties are unavoidable and can be caused by manufacturing tolerances and usage conditions. As a result of this, cells connected in series may have different voltages and states of charge that limit the energy and power capability of the complete battery pack. Methods of removing this energy imbalance have been extensively reported within literature. However, there has been little discussion around the effect that such variation has when cells are connected electrically in parallel. This work aims to explore the impact of connecting cells, with varied properties, in parallel and the issues regarding energy imbalance and battery management that may arise. This has been achieved through analysing experimental data and a validated model. The main results from this study highlight that significant differences in current flow can occur between cells within a parallel stack that will affect how the cells age and the temperature distribution within the battery assembly.
Prospective memory or memory for actions to be performed in the future is critical to everyday life and yet has been virtually ignored by researchers until recently. Relative to typically studied retrospective memory tasks, prospective memory retrieval is self-initiated in the sense that a person must remember to perform an intended action without an external request to search memory. This self-initiated characteristic has implications for understanding how retrieval occurs, the storage dynamics of prospective memories, and the optimal encoding strategies. We comprehensively review major theories and evidence on these issues as well as explore developmental changes in prospective memory. Finally, we review the neural processes underlying prospective memory.
The present study reports a simple and cost effective chemical approach for conveniently synthesizing cupric oxide nanostructures (CuO-NSs). To promote confined and stable growth of CuO-NSs, hexamine (HMT) capping molecules were used in the reaction process. Addition of capping molecule could greatly influence the size confinement of CuO-NSs which in turn affects the optical properties. Significant variations in surface morphology were attributed to the presence of hydroxide anion in HMT during synthesis process. Transmission electron microscopy (TEM) results indicated that much larger CuO-NSs are formed without using HMT. XRD analysis revealed that the sample without HMT gives higher crystallite size with less strain. Energy dispersive X-ray analysis with elemental mapping confirms the stoichiometric proportion of CuO-NSs. Micro-Raman and Fourier transform infrared spectroscopy results confirmed the effect of HMT on monoclinic structure. The optical properties of the prepared CuO-NSs were investigated using UV–visible diffuse reflectance spectroscopy and photoluminescence (PL) spectroscopy. Optical band gap energy of CuO-NSs was increased with increasing HMT concentration from half to equimolar ratio. The PL spectra of CuO-NSs revealed the presence of emission bands in violet, blue-green and IR region due to band-gap expansion presence of oxygen vacancies and carrier localization effect in the defect levels. The PL results were in good agreement with TEM observations. Controllable morphology of CuO-NSs with adjustable optical properties has shown excellent applicability in many applications such as catalysts, gas sensors and solar cells.
This study investigates the large voltage range of symmetric carbon/carbon capacitors in environmentally friendly aqueous lithium sulfate electrolyte. A high over-potential related to the hydrogen sorption mechanism at the negative electrode contributes usefully to enhance the operating voltage up to 1.9 V with an excellent stability during 10000 charge/discharge cycles. Such a voltage value is two times higher than the values generally demonstrated with symmetric carbon/carbon capacitors in conventional aqueous media, while avoiding the disadvantages of the corrosive properties of acidic and basic electrolytes. Temperature programmed desorption analysis of the electrodes after long-term cycling gives the evidence that the maximum voltage is essentially limited by an irreversible electro-oxidation process at the positive electrode. If the potential of the positive electrode goes beyond a given value during cell operation, a massive electro-oxidation of carbon leads to a further deleterious increase of the maximum potential of the electrode and an increase of electrode resistance resulting in a decrease of capacitance. Inconvenience can be sidestepped by performing a controlled chemical oxidation of the carbon surface using hydrogen peroxide. As a consequence, the maximum potential of the electrode remains stable during operation of the cell at 1.9 V, and the system can be charged/discharged during 10000 cycles with very moderate loss of capacitance or increase of resistance.
A well-known strategy to achieve higher energy density in lithium-based batteries consists in using metallic lithium as the anode, however, the problematics associated are many and well-known. One solution to enhance battery safety consists in protecting lithium by using a solid electrolyte. Herein the preparation of a new solid polymer composite electrolyte, encompassing room-temperature ionic liquid (RTIL) and ceramic powder is reported. The methacrylate monomer, easily reticulated by UV-curing allows to obtain a highly crosslinked 3D structure matrix, rich in ethoxy groups, fundamental for Li+ conduction. Encompassing of RTIL and ceramic particles allows an enhancement of the ionic conductivity as well as mechanical properties, therefore highly reducing lithium dendrite formation.
Brucellosis is a worldwide zoonosis and a significant cause of loss of health in human and animals. Conventionally, definitive diagnosis is done by isolation of brucellae which is time consuming, technically demanding and may be hazardous. The present study was aimed to develop PCR assay based on evolutionarily conserved outer membrane protein 22 gene for rapid diagnosis of Brucella spp. A set of primer was designed after multiple alignment of outer membrane protein 22 gene sequences by clustalW. PCR amplification resulted in single specific amplicon of 639 bp in all the Brucella strains tested. The primers were found to be highly sensitive and specific. PCR assay developed may be used for clinical diagnosis of Brucella infection.
The requirements for rechargeable batteries place high demands on the electrodes. Efficient storage means accommodating both ions and electrons, not only in substantial amounts, but also with substantial velocities. The materials’ space could be largely extended by decoupling the roles of ions and electrons such that transport and accommodation of ions take place in one phase of a composite, and transport and accommodation of electrons in the other phase. Here we discuss this synergistic concept being equally applicable for positive and negative electrodes along with examples from the literature for Li-based and Ag-based cells. Not only does the concept have the potential to mitigate the trade-off between power density and energy density, it also enables a generalized view of bulk and interfacial storage as necessary for nanocrystals. It furthermore allows for testable predictions of heterogeneous storage in passivation layers, dependence of transfer resistance on the state of charge, or heterogeneous storage of hydrogen at appropriate contacts. We also present an outlook on constructing artificial mixed-conductor electrodes that have the potential to achieve both high energy density and high power density.
The use of the Electrochemical Quartz Crystal Microbalance (EQCM) to study the proton intercalation performance of thin film Ni(OH)2 layers, nowadays widely used as cathode electrode material in rechargeable Ni(OH)2-based battery systems such as NiMH and NiCd, is reviewed. In addition, the impact of incorporating foreign metals in these layers on the electrochemical performance will be highlighted. Using EQCM much information can be obtained, as both the electrochemical response and accompanying mass changes can be measured simultaneously. EQCM was extensively used to investigate the effect of the conditions on the formation of Ni(OH)2 thin layers, the α-to-β modification changes and the details of the redox mechanism. The proposed redox mechanisms differ in whether H+ or OH− is transferred, the reactants and/or products are hydrated and cations from the solution take part in the reaction. By incorporation of other metals in the structure, the characteristics of thin Ni(OH)2 layers can be tuned. This affects the oxidation and reduction potential, the reversibility, the stability of the structure and the oxygen evolution side reaction. Co2+ and Fe2+ were shown to replace Ni-sites in the hydrous oxide lattice, thereby forming very dense structures with higher stability. However, structural changes still occur in most cases. Due to this inhomogeneity, the layers are usually a combination of different structures, depending on the distribution of the incorporated metal(s). Suppression of the oxygen evolution reaction is reported for Co, Pb, Pd, Zn and Mn. The effects of Co and Mn are shown to depend on the incorporated amount. Co shifts the standard redox potential for the oxygen evolution reaction towards more cathodic potentials and decreases the oxygen overpotential significantly. Light-weight rare-earth elements also catalyze the oxygen evolution reaction.
A nonlinear equivalent circuit model for lithium ion cells is developed where the circuit elements are based on electrochemical processes like charge transfer reaction, and variable resistances that are functions of the state variables. The potential drops are the natural state variables rather than cell state-of-charge (SOC). A commercial pouch cell consisting of composite positive and meso-carbon microbeads (MCMB) negative electrodes is analyzed. The state space model developed consists of the current balance which forms the state variable evolution equation and voltage balance which forms the output equation. The global set of parameters for a two pair resistor–capacitor circuit is calculated by solving the model equations consistently and minimizing the error with HPPC (Hybrid Pulse Power Characterization) pulse voltage at few SOCs. The entire HPPC protocol is predicted by the model accurately within an error of 50 mV. The model is validated using the full depth charge–discharge experiments. The model is used to resolve the overall cell potential into potential drops due to individual processes, yielding insights into controlling mechanisms. The variable resistor formalism enables cell voltage prediction without parameter re-estimation and hence can be developed as an on-board algorithm.
Many NiCoO2 flowers with an average diameter of about 4 μm were grown on the NiCoO2 flakes coated Ni foam (denoted as NiCoO2/Ni foam) through a simple hydrothermal method and confirmed by scanning and transmission electron microscopies, X-ray diffraction and X-ray photoelectron spectrum measurements. The NiCoO2/Ni foam with high specific area and porosity was directly used as the working electrode without any binders. The measured specific capacitance of NiCoO2 grown on Ni foam is 756 F/g at 0.75 A/g using a three-electrode setup in 1 M KOH. Considering the high capacity of NiCoO2 and the good stability of rGO, the NiCoO2/Ni foam//rGO hybrid supercapacitor combining NiCoO2/Ni foam and rGO shows very good properties, such as high specific capacitance (82 F/g at 2 A/g based on the total mass of active materials), high energy density (25.7 Wh/kg at 1500 W/kg based on the total mass of active materials), good stability (about 90% capacitance retention after 2000-cycle at 100 mV/s), and low charge ion transfer resistance.
A series of LaMn1±xO3 perovskite (x=0, 0.05, 0.1) has been synthesized via a facile sol–gel method and applied as supercapacitor electrodes. The morphology, phase structure, composition, chemical states of constituents and electrochemical properties are investigated. As a result, all the LaMn1±x O3 samples revealed a single mesoporous phase of perovskite with typical pore sizes from 2 to 5nm. The nonstoichiometric LaMn1.1O3 sample showed much higher specific capacity (202.1mAhg−1/727.6Cg−1 at 1Ag − 1) than stoichiometric LaMnO3 perovskite (114.4 mAhg−1/411.8Cg−1 at 1Ag − 1). Detailed chemical analysis demonstrated that the presence of point defects such as oxygen and cation vacancies, and a high Mn4+/Mn3+ ratio contributed to the excellent electrochemical performance. Furthermore, the cycle stability analyses of the LaMn1±xO3 perovskite revealed that LaMn1.1O3 manifested an exceptionally high rate capability. These results prove that nonstoichiometric LaMn1.1O3 can be a promising material for supercapacitor electrodes.
This paper describes the fabrication, experimentation and simulation stages of converting a 165l domestic electric refrigerator to a solar powered one. A conventional domestic refrigerator was chosen for this purpose and was redesigned by adding battery bank, inverter and transformer, and powered by solar photovoltaic (SPV) panels. Various performance tests were carried out to study the performance of the system. The coefficient of performance (COP) was observed to decrease with time from morning to afternoon and a maximum COP of 2.102 was observed at 7 AM. Simulations regarding economic feasibility of the system for the climatic conditions of Jaipur city (India) were also carried out using RETScreen 4. It was observed that the system can only be economically viable with carbon trading option taken into account, and an initial subsidy or a reduction in the component costs – mainly SPV panels and battery bank.
The rate of voltage fade in 0.5Li2MnO3·0.5LiNi0.375Mn0.375Co0.25O2 cathodes was measured in half-cells in a temperature range of 25–55 °C. On the basis of the dependence of the values of the open-circuit potential with cycle count and temperature, the voltage fade phenomenon seems to consist of two chemical processes: one that can be described using a parabolic rate law and another that uses a linear-with-time law. As the cycling temperature increased, the relative contributions of the two processes changed. On the basis of the overall rate versus temperature data, we believe the two processes may be in competition with one another.
Heat is a ubiquitous energy resource, which is easily accessible from the environment. The pyroelectric effect, a phenomenon that converts temperature variation into electricity, enables a material to be operated like a heat engine between high and low temperatures and electric fields, producing electrical work. However, current literature focuses on material performances, with no energy stored by operating in such conversion cycles. This work presents a complete pyroelectric management system that both realized cycled energy conversion and a maximum harvested power up to 13.1 μW. We achieved this by integrating a laser heat source, an advanced pyroelectric device, a practical power interface, and an energy storage component together. A thin film Lead Zirconate Titanate device was fabricated to achieve very fast temperature response (∼0.1 ms). Thus, the energy conversion can be achieved in a much higher thermodynamic frequency (1 kHz), leading to a larger power density. The proposed power interface manages an optimized pyroelectric conversion cycle while recharging a battery, or a storage capacitor (up to 2.1 V). The results provide a promising method to harvest energy from waste-heat and have shown great potential to supply power to small-scale, distributed devices. In addition, the application of the laser source has also enabled the system to achieve wireless power transmission, which would enable a more flexible way to supply power to multiple devices.
Hollingsworth & Vose has acquired Raman FibreScience Private Limited (RFS), a Mysore, India-based company that specialises in advanced materials for filtration media and battery separator applications.
Solid polymer gel electrolytes composed of 75wt.% of the ionic liquid, 1-n-butyl-2,3-dimethylimidazolium bis-trifluoromethanesulfonylimide with 1.0M lithium bis-trifluoromethanesulfonylimide and 25wt.% poly(vinylidenedifluoro-hexafluoropropene) are characterized as the electrolyte/separator in solid-state lithium batteries. The ionic conductivity of these gels ranges from 1.5 to 2.0mScm−1, which is several orders of magnitude more conductive than any of the more commonly used solid polymers, and comparable to the best solid gel electrolytes currently used in industry. TGA indicates that these polymer gel electrolytes are thermally stable to over 280°C, and do not begin to thermally decompose until over 300°C; exhibiting a significant advancement in the safety of lithium batteries. Atomic force microscopy images of these solid thin films indicate that these polymer gel electrolytes have the structure of nano-sponges, with a sub-micron pore size. For these thin film batteries, 150 charge–discharge cycles are run for Li x CoO2 where x is cycled between 0.95 down to 0.55. Minimal internal resistance effects are observed over the charging cycles, indicating the high ionic conductivity of the ionic liquid solid polymer gel electrolyte. The overall cell efficiency is approximately 98%, and no significant loss in battery efficiency is observed over the 150 cycles.
A sol–gel method is employed to prepare high capacity Si–O–C materials. A blend of polysiloxane and divinylbenzene is uniformly spread in the ethanol solution of triethoxysilane and diethoxymethylsilane, which is then hydrolyzed, crosslinked and finally pyrolyzed at 1000 °C in a hydrogen atmosphere to obtain the final composite materials. The resultant materials, as indicated by elemental analysis, mainly consist of Si–O–C glass phase, in which the dominant silicon species is identified to SiO4 units by 29Si magic angle spinning nuclear magnetic resonance and Si (2p) X-ray photoelectron spectroscopy. The Si–O–C materials exhibit a stable reversible capacity of ca. 900 mAh g−1, originating from lithium storage in SiO4 units, with a coulombic efficiency of 98.5%.
A central challenge in large scale sustainable hydrogen production by electrolyzing water is to develop efficient and economical electocatalysts with nanostructural materials. This work herein reports the facile solvothermal synthesis of MoS2/Co3S4 hollow nanostructural co-catalyst with high activity and stability for electrochemical hydrogen evolution reaction (HER) by compositing cheap and HER-active MoS2 on Co3S4 HER catalyst. By morphology and structure modulations, this high-quality nanostructure, which is confirmed by several characterizing techniques, can be considered as excellent catalyst to split water into H2 in a wide pH range via the electric drive. Corresponding electrochemical measurement results of 55.6 mV dec−1 and 115.3 mV dec−1 Tafel slope in acid (pH = 0.3) and alkaline (pH = 14) media demonstrates our predictions. We believe that such performance improvement is mainly due to the much increased active sites for catalysis because of composition process and hollow structure. These findings open up an effective and propagable strategy for nanostructural HER catalysts synthesis.
In this study, we report the application of an inexpensive and easily prepared lead oxide–manganese oxide catalyst combined with Nafion (designated as Nf/PbMnO x ) as a highly efficient air-cathode for a zinc–air battery. We verify the mechanistic study of the reduction of O2 for Nf/PbMnO x in alkaline aqueous solution using rotating ring/disk electrode voltammetry, and also an electrochemical approach using a wall-jet screen-printed ring disk electrode. The presence of Nf/PbMnO x shows great catalytic activity for the disproportionation reaction of HO2 − to O2 and OH− with an overall 4e− reduction of O2 in the first reduction reaction. The 4e− reduction of O2 was eventually achieved at the Nf/PbMnO x through evidence from the slope of Koutecky–Levich plots. With these inherent features, we then fabricated the zinc–air battery with the Nf/PbMnO x catalyst and examine the performance for a practical application with air cathodes.
Recent results from diffusion tensor imaging (DTI) studies provide evidence of a ventral-lexical stream and a dorsal-sublexical stream associated with reading processing. We investigated the relationship between behavioural reading speed for stimuli thought to rely on either the ventral-lexical, dorsal-sublexical, or both streams and white matter via fractional anisotropy (FA) and mean diffusivity (MD) using DTI tractography. Participants (N = 32) overtly named exception words (e.g., ‘one’, ventral-lexical), regular words (e.g., ‘won’, both streams), nonwords (‘wum’, dorsal-sublexical) and pseudohomophones (‘wun’, dorsal-sublexical) in a behavioural lab. Each participant then underwent a brain scan that included a 30-directional DTI sequence. Tractography was used to extract FA and MD values from four tracts of interest: inferior longitudinal fasciculus, uncinate fasciculus, arcuate fasciculus, and inferior fronto-occipital fasciculus. Median reaction times (RTs) for reading exception words and regular words both showed a significant correlation with the FA of the uncinate fasciculus thought to underlie the ventral processing stream, such that response time decreased as FA increased. In addition, RT for exception and regular words showed a relationship with MD of the uncinate fasciculus, such that response time increased as MD increased. Multiple regression analyses revealed that exception word RT accounted for unique variability in FA of the uncinate over and above regular words. There were no robust relationships found between pseudohomophones, or nonwords, and tracts thought to underlie the dorsal processing stream. These results support the notion that word recognition, in general, and exception word reading in particular, rely on ventral-lexical brain regions.
The ever-increasing demands for energy and environmental concerns due to burning fossil fuels are the key drivers of today's R&D of innovative energy storage systems. This paper provides an overview of recent research progress in graphene-based materials as electrodes for electrochemical energy storage. Beginning with a brief description of the important properties of single-layer graphene, methods for the preparation of graphene and its derivatives (graphene oxide and reduced graphene oxide) are summarized. Then, graphene-based electrode materials for electrochemical capacitors and lithium-ion batteries are reviewed. The use of graphene for improving the performance of lithium–sulfur and lithium–oxygen batteries is also presented. Future research trend in the development of high-power-density and high-energy-density electrochemical energy storage devices is analysed.