batterydata/paper-abstracts huggingface dataset:
The cathode−electrolyte interface (CEI) is a key factor that affects the electrochemical performance of lithium-ion batteries. However, considerable ambiguity still exists with regard to the composition and properties of the CEI at different potentials during cycling. In this study, we investigate the dynamic evolution behavior of the CEI between the LiNi0.6Co0.2Mn0.2O2 cathode and organic carbonate electrolytes by electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS), and synchrotron soft X-ray absorption spectroscopy (soft XAS). XPS results reveal the continuous formation and decomposition of the CEI components during the initial charge and discharge process. Lithium alkyl carbonates and lithium fluoride (LiF) form during charging at low voltages, decompose at high voltages, and regenerate during discharging. In addition, soft XAS highlights the formation of electrochemically inactive species on the cathode surface, which generates extra barrier for Li+ diffusion and also decreases active sites for Li+ intercalation. The surface Ni undergoes incomplete oxidation during the charging process and exhibits partial reduction after discharging. These results are consistent with impedance variation in the first cycle and morphology changes on the cathode surface. These findings underscore the value of investigating and regulating the interfacial properties of lithium-ion batteries.
Objective The purpose of this study was to evaluate the reliability of the vestibular evoked myogenic potential (VEMP) response in a clinical setting when only a feedback mechanism is available for monitoring background EMG. Methods Sixty-one healthy subjects participated in the investigation of the within-session reliability, whereas fourteen of them were retested after one week for examination of the between-session reliability. VEMPs were recorded using 500Hz tone bursts with the subjects in a sitting position and their heads turned away from the test ear to the contralateral shoulder, thereby pushing their chin against the inflatable cuff of a blood pressure manometer, serving as feedback method. Results The feedback method revealed latency and amplitude values comparable to other data in the literature where different test conditions were applied. Excellent reliability with ICC values ranging from 0.78 to 0.96 and CVME values ranging from 4% to 36%, was achieved for P1 and N1 latency, threshold and interpeak amplitude. Good reliability with ICC values of 0.65 and 0.68 and CVME values of 170% and 189%, was obtained for the asymmetry ratio. Conclusions A unilateral muscle contraction controlled by a feedback mechanism resulted in reliable response parameters, comparable right to left and corresponding to literature data obtained in different test conditions. Significance The use of a blood pressure manometer as feedback mechanism combined with a meticulously controlled positioning of the head and contraction of the SCM muscle provides a reliable alternative in clinical settings, when the background muscle contraction cannot be measured or software related correction algorithms are not accessible.
Functionalized three-dimensional hierarchical porous carbon (THPC) is prepared via a facile modified chemical activation route with polypyrrole microsheets as precursor and KOH as activating agent. The as-obtained THPC presents a large specific surface area (2870 m2 g−1), high-level heteroatom doping (N: 7.7 wt%, O: 12.4 wt%), excellent electrical conductivity (5.6 S cm−1), and hierarchical porous nano-architecture containing macroporous frameworks, mesoporous walls and microporous textures. Such unique features make the THPC an ideal electrode material for electrochemical energy storage. As the electrode material for a supercapacitor, the THPC exhibits a high capacitance, excellent rate performance and long-term stability in both aqueous and organic electrolytes.
A novel durability-reinforced electrochromic device (ECD) is described, in which the electrochromic materials remain in different physical form. Solution-phase ethyl viologen is used as the working electrochromic material, and modified Ti-doped V2O5 is utilized as counter electrochromic material. Electrochromic and spectral performances of the device are recorded here. The ECD shows good electrochromic performances in the visible and utraviolet region. Particularly, it’s worth mentioning that the ECD could work for 250,000 cycles at 60°C, with transmittance of 70% and 8% between bleached and colored states at the wavelength of 600nm, which shows remarkable long term stability. The excellent durability are mainly attributed to the reasonable choice of matching states and durability reinforced Ti-V2O5 film: the color change, charge capacity and switching speed of the viologen solution could be controlled through adjusting the concentration, and the addition of Ti provides excellent stability due to the distorted V2O5 layer structure.
Property prices across many OECD countries have witnessed remarkable increases over the past 10 years. Two factors frequently posited for this boom are higher income levels and the benign interest rate environment experienced in many of these countries. However, empirical models of house prices struggle to achieve credible results concerning the impact of interest rates with coefficients that are frequently insignificant or of the wrong sign. In this paper we propose an intuitive theoretical model of house prices where the demand for housing is driven by how much individuals can borrow from financial institutions. This level of borrowing depends on disposable income levels and current interest rates. We empirically test this model by applying it to the Irish property market. Our results support the existence of a long-run relationship between actual house prices and the amount individuals can borrow with plausible and statistically significant adjustment to this long run equilibrium.
Industrial waste AlSiFe powders are employed to provide polyporous SiO2 frameworks by alkali etching and Si nanoparticles are embedded in the gaps of the porous SiO2 frameworks via ultrasonic stirring. The nitrogen doped carbon layers are generated on the surface of the porous frameworks to yield the Si–SiO2@Fe/NC composite by polymerization of dopamine and subsequent carbonization process, in which the polyporous SiO2 frameworks can not only relieve huge volume changes of the active Si particles, but also can provide abundant charge transfer channels for electrons and lithium ions. Moreover, the nitrogen doped carbon layers significantly promote the electronic conductivity of the composite. Benefitting from these coordinating effects, the Si–SiO2@Fe/NC anodes demonstrate outstanding cycle performance with a charge specific capacity of 1394.7 mAh g−1 and up to 100% capacity retention rate after 100 cycles under test current of 200 mA g−1, excellent rate performance with a charge specific capacity of 653.1 mAh g−1 under test current of 3000 mA g−1 and enhanced lithium ion diffusion rate of 4.161 E−13 cm2 s−1 in the 100th cycle. As a consequence, the comprehensive fabrication of the Si–SiO2@Fe/NC composite from industrial wastes could provide a promising idea to develop novel anodes for lithium ion batteries.
Ni-NiO-CNT composite synthesized by swift and simple combustion process is investigated as anode for Li-ion batteries (LIB) and also as an electro-catalyst for oxygen evolution reaction (OER) in alkaline medium. The binder free, electrical conductor less, free standing anode fabricated from Ni-NiO-CNT displays a stable capacity of 736mAhg−1 at a current density of 200mAg−1 for the investigated 50 cycles, the exhibited capacity being higher than the theoretical capacity of NiO and carbon. The hybrid composite also exhibits excellent OER activity, achieving current density of 10mAcm−2 at a lower over potential (η) of 320mV. The presence of Ni nanoparticles and porous sponge like structure of the composite is the main reason for this high performance. Such multifunctional materials could emerge as promising for realizing future energy storage and conversion approaches.
The unique eleven electron per molecule electrochemical oxidation of vanadium diboride (VB2) combined with an air cathode provides VB2/air batteries that have extremely high theoretical energy densities. Testing of VB2/air cells at various discharge times showed that VB2/air batteries containing nanoscopic VB2 anodes provide higher capacities and voltages than cells containing macroscopic VB2 anodes. The structure and properties of nanoscopic VB2 were compared with those of macroscopic VB2 to provide further insight into the enhanced electrochemical performance of the nanomaterial. From nitrogen physisorption and electrical conductivity measurements, we determined that the higher performance of the nanoscopic VB2 material compared with the macroscopic VB2 material may result from the combination of the nanomaterial's higher surface area and higher electronic conductivity. The thickness of the zirconia layer applied to prevent corrosion in alkaline electrolyte was shown by transmission electron microscopy and energy dispersive X-ray spectroscopy to be ca. 3-40 nm which may allow rapid discharge through the coating. Electrochemical impedance spectroscopy results showed that for cells containing both the macroscopic and the nanoscopic materials the resistance associated with charge transfer increases during the discharge process. The results provide a basis for further development of high energy and power density VB2/air batteries.
Controlling the electrochemical performance of electrodes for application in supercapacitor has received large research interest in the recent years. Here we report the facile synthesis of a Ni(OH)2 and carbon nanotubes based nanohybrid electrode and control its electrochemical performance for application in supercapacitor by La doping. A systematic investigation of the influence of a number of electrochemical parameters of measurement on the electrode properties is also presented. Structural and morphological analyses show formation of hexagonal nanoparticles (∼35 nm) well attached on the walls of carbon nanotubes (CNT) while elemental analysis confirms the success of La doping. The nanohybrid sample doped with 1 mol% La (with respect to Ni) appears to be the best performing electrode exhibiting specific capacitance of 2731 F/g at 1 A/g, energy density of 25 Wh/kg at power density of ∼1 kW/kg and capacity retention of 84% even after 5000 cycles which are higher than previously reported values for Ni(OH)2 based electrodes and also the first of its kind in which β-Ni(OH)2 has been combined with CNT and doped with La. Increase in the specific surface area as well as electrical conductivity of Ni(OH)2 by incorporation of CNT and La dopants are the main reasons for the improved performance of the 1 mol% La doped composite whereas formation of insulating La(OH)3 is responsible for the inferior performance of electrodes containing more than 1 mol% La. The charge storage mechanism has been found to be governed by both capacitive and diffusion processes at high scan rates but dominated by only diffusion process at low scan rates.
Novel surface modification approach for graphite anode of lithium ion batteries was developed in this study. Poly(acrylonitrile) was in situ encapsulated on the surface of natural graphite (N-graphite) particles via radiation-initiated polymerization. The graphite obtained shows a large improvement in electrochemical performance such as initial Coulombic efficiency and cycleability compared with the original N-graphite. The structural stability of graphite surface is enhanced due to the fact that encapsulated poly(acrylonitrile) can depress the co-intercalation of solvated lithium ion.
Technology has characteristics of inducing changes under competitive environment due to its dynamic property of being modified and accelerated over time. In order to improve profitability, the evaluation of technology transfer adoption (TTA) is very important for determining the weights of TTA factors, the influence of the organizational factors (i.e., the measures of TTA dimension) such as chief executive officer (CEO)’ mind and capacity, commercialization, and technology licensing office (TLO)’s competence on the profitability of emerging technologies (ET), and the size of these organizational factors in suppler and buyer. This research investigates the important intangible priority factors for the transfer of technology through analytic hierarchy process (AHP) method and correlation analysis. The study is based on three phases: (1) Phase 1: selection of TTA factors and the measures of ET, TTA, and bargaining power (BP) dimension; (2) Phase 2: correlation analysis between the measures of ET and TTA dimension (evaluation of TTA dimension based on the measures of ET); (3) Phase 3: evaluation of TTA dimension based on the measures of BP dimension. The quantitative weights of criteria, TTA factors and sub-factors are provided and they indicate the order of priority and the degree of importance for TTA. The results are interpreted in terms of the ET and BP dimensions of measures that need to be considered in order to provide assistance at the time of decision-making on adoption of technology transfer by companies.
Thin films of polypyrrole (Ppy) and poly-2,5-dimercapto-1,3,4-thiadiazole (poly(DMcT)) are electrochemically deposited on pieces of carbon fiber (CF) cloth, yielding flexible and high surface area composites that are characterized as electrodes for supercapacitors. A bilayered polymeric composite (CF/poly(DMcT)/Ppy) is obtained by depositing a nanometric layer of Ppy on CF already supporting a poly(DMcT) film. Electrochemical stability tests indicate that the Ppy film acts as a barrier that prevents the loss of the poly(DMcT) electroactive material, thus improving the charge-storage characteristics of the bilayered film even after 1000 cycles. Specific capacitance values of 460±50 and 1130±100Fg−1 are observed for electrodes made of the CF/Ppy and CF/poly(DMcT)/Ppy composites, respectively. Comparatively to similar Ppy composite materials used for supercapacitors, the bilayered film electrode here reported presents a significantly improved specific capacitance value.
We report results of the studies relating to the fabrication of a highly sensitive label free biosensor based on graphene oxide (GO) platform for the detection of aflatoxin B1 (AFB1) which is most toxic and predominant food toxin, using electrochemical impedance spectroscopy. The structural and optical characterization of GO/Au and anti-AFB1/GO/Au has been done by electron microscopy, Raman, X-ray diffraction (XRD), UV–vis and electrochemical impedance spectroscopy (EIS). The impedimetric sensing response of immunoelectrode as a function of AFB1 concentration reveals wider linear detection range (0.5–5 ng/ml), high sensitivity (639 Ω ng−1 ml), improved detection limit (0.23 ng ml−1) and good stability (5 weeks) for the label-free detection. Association constant (ka) for antigen–antibody interaction obtained as 0.46 ng ml−1 indicates high affinity.
One important issue in future scenarios predominantly using renewable energy sources is the electrochemical storage of electricity in batteries. Among all rechargeable battery technologies, Li-ion cells have the largest energy density and output voltage today, but they have yet to be optimized in terms of capacity, safety and cost for use as stationary systems. Recently, sodium batteries have been attracting attention again because of the abundant availability of Na. However, much work is still required in the field of sodium batteries in order to mature this technology. Sodium superionic conductor (NASICON) materials are a thoroughly studied class of solid electrolytes. In this study, their crystal structure, compositional diversity and ionic conductivity are surveyed and analysed in order to correlate the lattice parameters and specific crystal structure data with sodium conductivity and activation energy using as much data sets as possible. Approximately 110 compositions with the general formula Na 1 + 2 w + x − y + z M w ( II ) M x ( III ) M y ( V ) M 2 − w − x − y ( IV ) ( SiO 4 ) z ( PO 4 ) 3 − z were included in the data collection to determine an optimal size for the M cations. In addition, the impact of the amount of Na per formula unit on the conductivity and the substitution of P with Si are discussed. An extensive study of the size of the structural bottleneck for sodium conduction (formed by triangles of oxygen ions) was carried out to validate the influence of this geometrical parameter on sodium conductivity.
The electrochemical behavior of new high potential electrolyte containing sebaconitrile in LiPF6/EC:DMC or LiBF4 was studied on glassy carbon and LiCoO2, LiCoPO4 as positive electrode materials. The increase of sebaconitrile concentration in EC:DMC electrolyte provides better electrolyte stability at higher potentials on glassy carbon as observed by cyclic voltammetry. Promising electrochemical results showing good reversibility and insertion/deinsertion efficiency have been also obtained on LiCoPO4 electrode cycled up to 5.3V vs Li+/Li as upper potential limit. However, the cycling of LiCoPO4 at higher potential (6V vs Li+/Li) shows lower reversibility and efficiency of insertion/deinsertion process due to the oxidative decomposition of the electrolyte at high potentials. The surface analysis performed by X-ray photoelectron spectroscopy confirms the formation of a surface layer induced by electrolyte degradation on both types of positive electrodes, which hinder the Li diffusion. The layer composition and morphology vary as a function of electrolyte composition and type of electrode.
Carbon-coated LiMnPO4 is prepared by PVP (polyvinyl pyrrolidone)-assisted solid-state reaction. The structure and morphology of the materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The electrochemical properties of the materials are investigated by galvanostatic charge–discharge test. It is found that the introduction of grinding aid (PVP) in the precursor caused uniform and smaller particle size in the final products, resulting in a regular carbon coating layer around the LiMnPO4 particles. As a result, an improved electrochemical performance is obtained. The carbon-coated LiMnPO4 exhibits a high capacity, a good cyclability and an excellent rate capability. These excellent results are elucidated by electrochemical impedance spectroscopy test, which show that there is decrease of charge transfer resistance and faster Li-ion diffusion in carbon-LiMnPO4 cathode materials after adding PVP.
The safety design of systems using lithium-ion batteries (LIBs) as power sources, such as electric vehicles, cell phones, and laptops, is difficult due to the strong multiphysical coupling effects among mechanics, electrochemistry and thermal. An efficient and accurate computational model is needed to understand the safety mechanism of LIBs and thus facilitate fast safety design. In this work, a detailed mechanical model describing the mechanical deformation and predicting the short-circuit onset of commercially available 18650 cylindrical battery with a nickel cobalt aluminum oxide (NCA) system is established for the first time. The mechanical properties of anode, cathode, and separator are characterized. Based on the experiment results, the constitutive models of component materials are established and validated through numerical simulations. A detailed computational model including all components (i.e., separator, anode, cathode, winding, and battery casing) is then developed by evaluating four typical mechanical-loading conditions. Short-circuit criteria are subsequently established based on the separator failure, thereby enabling the mechanical model to predict the short circuit electrochemically. Results show that the model can describe LIB behaviors from mechanical deformation to internal short circuit. Results provide a powerful tool for the safety design of LIBs and related engineering systems.
Porous TiO2 urchins have been synthesized by a hydrothermal route using TiO2/oleylamine as precursors with subsequent ion-exchange and calcination. The resultant material consists of porous spherical cores and nanochains-constructed shells with straight channels. Electrochemical measurements indicate the TiO2 urchins deliver superior lithium storage capability in terms of high capacity (206.2mAhg−1 at 0.5C), superior rate performance (94.4mAhg−1 at 20C) and stable cycling stability (94.3% capacity retention over 1000 cycles at 10C versus the third cycle). Such performance enhancement is mainly due to the increased electrode/electrolyte contact interface, reduced Li+ diffusion pathways and improved mass transfer of electrolyte in the unique 3D interconnected hierarchical network. In addition, ex-situ XRD, SEM and TEM analyses further reveal high structure integrity of the porous TiO2 urchins during the electrochemical lithiation, leading to enhanced lithium storage stability. Moreover, we detected that some anatase nanocrystals evolved into electrochemically inactive Li1TiO2 dots (∼10nm in size) during long-term electrochemical cycling. Our findings provide more insights for better understanding of the structure evolution and capacity decay mechanism in porous TiO2 nanostructures.
Transition metal Ni- and Co-based oxides are potential candidates to replace expensive and scarce noble metal-based oxygen evolution reaction (OER) catalysts such as IrO2 and RuO2, which are required for efficient hydrogen production from solar water splitting and rechargeable energy storage technologies. So far, layered NiFe double hydroxide represents the best OER activity among all Ni- and Co-based oxides. Here, we report new layered Na1−xNiyFe1−yO2 double oxide OER catalysts exhibiting activity and stability surpassing those of noble metal OER catalysts including IrO2 and RuO2, and a layered NiFe double hydroxide OER catalyst. The superior catalytic properties can be ascribed to the layered structure as well as the enhanced covalency of Ni and Fe. Powered by a lead halide perovskite solar cell with a power conversion efficiency of 14.69%, a two-electrode solar water-splitting device combining a Na0.08Ni0.9Fe0.1O2 OER catalyst with a NiP hydrogen evolution reaction catalyst delivers a solar-to-hydrogen conversion efficiency of 11.22%. Our design and fabrication strategies offer insights for developing highly active electrocatalysts for water splitting and metal–air batteries.
Almost all technical development efforts in both the developed and the developing nations depend on electrical energy. However, the sources of conventional means of electricity generation are fast depleting. Consequently, most industrialised nations have research on solar energy as a way to avert impending energy crisis. This paper presents the investments in energy generation in Nigeria. The efforts made in solar energy research and utilization are highlighted. The financial investments by the Nigerian government to the development of electrical power industry between 1990 and 1994 are presented and discussed. A case is made for a systematic and coordinated financial investments in solar energy research and adaptation to complement power generation from conventional sources.