batterydata/paper-abstracts huggingface dataset:
Sol–gel encapsulated glucose oxidase (GOx) enzyme electrodes based on carbon film resistors with chemically deposited copper hexacyanoferrate (CuHCF) or poly(neutral red) (PNR), made by electrochemical polymerisation, as redox mediator have been developed and characterised using cyclic voltammetry, electrochemical impedance spectroscopy and atomic force microscopy. The sol–gel was prepared using three different trioxysilanes: 3-aminopropyl-triethoxysilane (APTOS), 3-glycidoxypropyl-trimethoxysilane (GOPMOS) and methyltrimethoxysilane (MTMOS), without alcohol addition, and alcohol formed during the hydrolysis of the precursor compounds was removed. The best sensitivity, ∼60nAmM−1, for glucose and limit of detection (2–40μM, depending on the sol–gel precursor) were obtained when PNR was used as a mediator, but the linear range (50–600μM) was two to four times lower than that at CuHCF mediated biosensors, using an operating potential of +0.05 V at CuHCF or −0.25V versus saturated calomel electrode (SCE) at PNR mediated electrodes. The stability of the sensor depended on the sol–gel morphology and was 2 months testing the biosensor every day, while the storability was at least 4 months in the case of GOPMOS, the sensors being kept in buffer at +4°C.
In order to improve high-rate performance of lithium iron phosphate (LiFePO4, LFP) cathodes, the LFP and activated carbon (AC) layers were coated on one side and the other side, respectively, of an aluminum (Al) current collector (producing the LFP/AC cathode), and then through-holes with the average diameter of 22.8 μm and opening rate (R opening) of 0.64% were formed in the LFP/AC cathode (producing the through-holed LFP/AC cathode). The cell fabricated with one through-holed LFP/AC cathode and two lithium (Li) metal anodes exhibited a significantly improved high-rate performance in the C-rate region of 50–100 C. The through-holed LFP/AC cathode was found to be superior in high-rate performance to a through-holed LFP/LFP cathode, where the LFP layers were coated on the both sides of an Al current collector, and a LFP/AC cathode having no through-holes. From the results obtained, it was found that, in a high-rate discharging process, AC layer is at first discharged because of its higher high-rate performance than the LFP layer and then energy (electrons) is (are) transferred by the difference in the electrode potential between the AC and LFP layers from the charged LFP layer to the discharged AC layer with the transfer of Li+ ions via through-holes from the AC layer to the LFP layer (i.e., the AC layer is charged again) and a series of such processes are repeated. Forming through-holes in the LFP/AC cathode results in an improvement in its charging/discharging capacity and high-rate performance.
Electrochemical supercapacitive properties of polyaniline (PANI)/cobalt hydroxide (Co(OH)2)–nickel hydroxide (Ni(OH)2) nanocomposite (NC) electrode materials, synthesized potentiostatically via a electrochemical deposition method, are explored and compared with PANI and Co(OH)2–Ni(OH)2 electrode materials. From the surface analysis, an amorphous PANI, NCs and Co(OH)2–Ni(OH)2 are entirely different from one another. The PANI surface demonstrates nanofibrous morphology, NCs exhibits nanofiber-platelet morphology and Co(OH)2–Ni(OH)2 endows platelet-type surface morphology. The electrochemical properties of the PANI, NCs and Co(OH)2–Ni(OH)2 electrode materials are obtained from the cyclic-voltammetry and galvanostatic charge-discharge measurements. The specific capacitances of PANI, NCs and Co(OH)2–Ni(OH)2 measured at a sweep rate of 10 mV/s in a 1.0 M NaOH electrolyte are found to be 0.59, 50.0–74.1 and 312.5 F/g, respectively. The retention values of PANI, NCs and Co(OH)2–Ni(OH)2 obtained at the same scan rate for 1000 cycles are 25.8, 70.5–57 and 42.4%, respectively. This work clearly illustrates the reasons for a weak electrochemical performance of PANI and its composites with Co(OH)2–Ni(OH)2 in alkaline electrolyte over Co(OH)2–Ni(OH)2 electrode material.
The Fiji solar home system (SHS) program provides electricity, primarily for lighting, for remote households located in rural areas where supplying electricity via the grid is not feasible. The program is implemented by the Department of Energy (DoEF) and although initially designed on the RESCO model, the program as currently implemented is based on a partial RESCO approach as the government rather than a service company has full responsibility for program delivery. Donor-supplied capital is used for the initial equipment purchase and installation costs and all equipment and components supplied and installed under the program are owned by the government. A survey of both SHS users and those involved in the program design, planning and implementation was undertaken in order to obtain a better understanding on the Fijian SHS program, the approach used, the delivery method, the policy framework within which it is implemented and the overall the effectiveness of the program. This, in turn, helps to understand how SHS programs being implemented elsewhere can be improved. The main survey finding was that the effectiveness of the implementation of the Fijian SHS program is seen by many stakeholders to suffer from a lack of well developed planning and policy support. This manifests itself in a lack of support infrastructure and in a weak monitoring and maintenance program, which in turn give rise to significant technical problems. Many stakeholders consider there to be significant capacity for increasing the effectiveness of the program by the development of a more comprehensive and robust monitoring system, the provision of quality post-installation services, and the use of higher quality components. A number of measures that could be adopted to improve the effectiveness of the program at little or no cost are suggested.
Copper and cobalt (Cu–Co) are strategic metals for the Democratic Republic of Congo (DRC), and nearly 20% of the country's GDP is supported by their exports. At present, the country classifies itself as the leading copper producer in Africa with an output in the region of a million tonnes and possesses nearly 60% of the world's reserves of Co; a metal exclusively exported in the form of salts or semi-finished products. Concentrators play a very important role in the growth of Cu–Co metal production, which is needed in order to meet rapidly growing global demand and to increase government revenues through mining royalties. This article reviews the major process flow sheets and reagent suites in practice at concentrators operated in the DRC for the beneficiation of Cu–Co values from various ore types. The comprehensive compilation of pertinent laboratory and industrial data is intended to provide practising specialists, metallurgists, and academics conducting research on Congolese Cu–Co ores with a single well-detailed reference source. Emphasis is placed on froth flotation as the major technique for the beneficiation of Cu–Co minerals.
The thermal stability of a fully delithiated cathode, coupled with an inorganic salt, organic solvents, and electrolyte, was evaluated with differential scanning calorimetry (DSC) to address the safety issue of lithium-ion batteries. The DSC experiments revealed that vinylene carbonate (VC)-based systems exhibit decreased thermal stability compared to other coexisting systems. The DSC analysis of the cathode and electrolyte in the presence of VC, employed as additives, confirmed the reduction in thermal stability. Our results suggested that VC additives, which have been recently employed to enhance the electrochemical performance in anodes, negatively affect the thermal properties and safety characteristics of the cathode in lithium-ion batteries.
We studied the photoresponse of a membrane electrode of stoichiometric LiCoO2 used in lithium ion batteries. The electrode LiCoO2 in contact with dimethyl carbonate, propylene carbonate and LiClO4 presents the behavior of a p-semiconductor/electrolyte junction. The deinsertion of lithium of the LiCoO2 suppresses the photoresponse at 3.9 V versus the lithium potential. The reappearance of the photoresponse after re-intercalation suggests that the alterations in the electronic structure of the Li x CoO2 electrode probed by the photoelectrochemical experiments during deinsertion are reversible until x=0.5. The direct band gap energy of the LiCoO2 stoichiometry is 2.5 eV before and after lithium reinsertion. The experiments showed also that a small photo-intercalation current is observed in this cathodic material.
Estimates of pre-morbid IQ are widely used to measure the trajectory of cognitive function and decline in people with schizophrenia. This study examined the usefulness of two indices of decline to identify cognitive subtypes in first episode psychosis, and to determine the specificity of non-IQ neuropsychological impairments in this population. Neuropsychological data were collected from 118 first episode psychosis patients and compared to 118 epidemiologically matched controls. The National Adult Reading Test (NART) and the Information subtest of the WAIS-III were compared as indicators of crystallised intelligence or ‘pre-morbid IQ’. Measurement of NART minus current full scale IQ (FSIQ) (where 10 points discrepancy is the decline criterion) did not reveal a large group of individuals with ‘deteriorating’ IQ patterns. Using the Information subtest and the same decline criteria, a ‘deteriorating’ patient group emerged (36%) but was matched by a larger ‘deteriorating’ control group (45%). The ‘deteriorating’ patient group performed at a low IQ level for tasks that loaded highly on performance ability but a relatively high level for tasks measuring verbal skills. Verbal memory discriminated patients from controls better than IQ. Compared to controls, patients showed large selective impairments of verbal episodic memory (effect size, d=1.4) These data suggest that in first episode populations, caution should be exercised in inferring deterioration of IQ from discrepancies between reading-based and other IQ tests. Rather, sub-groups of patients and controls do show greater verbal aptitude in comparison to performance skills. Memory is generally impaired in first episode patients regardless of IQ.
Vanadium redox flow batteries (VRFBs) have been highlighted for use in energy storage systems. In spite of the many studies on the redox reaction of vanadium ions, the mechanisms for positive and negative electrode reaction are under debate. In this work, we conduct an impedance analysis for positive and negative symmetric cells with untreated and heat-treated carbon felt (CF) electrodes to identify the reaction mechanisms. The negative electrode reaction (V2+/V3+) is highly dependent on the heat treatment and reaction temperature, which is a feature of an inner-sphere mechanism, whereas the positive electrode reaction (VO2 +/VO2+) reaction is rather insensitive to the heat treatment and reaction temperature, suggesting an outer-sphere mechanism. An atomistic molecular dynamics simulation suggests that the different mechanisms are quite feasible considering the difference in the structure of the hydration shell for the vanadium ions. The deeper understanding of the reaction mechanism and its influence on cell performance will be helpful to advance VRFBs.
A comparative study of various electrode binders for graphite electrodes was conducted in a carbonate-based electrolyte with a high content of propylene carbonate (PC) as a means to evaluate anode degradation in presence of different binders. Because of its direct contact with the active material, a binder can be interpreted as an interfacial layer and as a local part of the electrolyte, the properties of which greatly depend on the interaction with the liquid electrolyte. In this work we demonstrate how a carefully chosen binder can create a specific surface environment that can protect graphite from exfoliation when the binder exhibits poor solubility in the electrolyte solvent and good surface adhesion to the active material. The exceptional stability of graphite electrodes containing poly(acrylic acid) sodium salt (PAA-Na) and carboxymethyl cellulose sodium salt (CMC-Na), respectively, in a PC-rich electrolyte is explained through the understanding of binder swelling and functionality. Interfacial resistances and electrochemical stability were investigated with impedance spectroscopy and galvanostatic cycling. Electrode morphologies and distributions of material were analysed with SEM and EDX. Evidence is presented that the surface selectivity increases with concentration of functional groups and polymer flexibility. Therefore only the less selective, stiff polymer with less functional groups, CMC-Na, provides sufficient protection at low binder contents.
Highly saline produced water was released from multiple sources during oil field operations from 1913 to 1973 at the USGS research Site A on Skiatook Lake in northeastern Oklahoma. Two pits, designed to hold produced water and oil, were major sources for release of these fluids at the site. Produced water spills from these and other features moved downslope following topography and downdip by percolating through permeable eolian sand and colluvium, underlying permeable sandstone, and, to a lesser extent, through shales and mudstones. Saline water penetrated progressively deeper units as it moved through the gently dipping bedrock to the north and NW. A large eroded salt scar north of the pits coincides with underlying fine-grained rocks that have retained substantial concentrations of salt, causing slow revegetation. Where not eroded, thick eolian sand or permeable sandstone bedrock is near the surface, and vegetation has been little affected or has reestablished itself after the introduced salt was flushed by precipitation. The extent of salt-contaminated bedrock extends well beyond existing surface salt scars. These results indicate that one of the legacies of surface salt spills can be a volume of subsurface salinization larger than the visible surface disturbance.
The commercialized LIBs employing graphite as anodes currently suffer a series of problems from the safety, theoretical capacity (372 mAh g−1) and rate capability. Herein, self-assembly mesoporous Zn ferrite (ZnFe2O4) microsphere embedded into carbon network has been synthesized by a facile method in the presence of citric acid. The Zn ferrites as an anode material with novel structure demonstrate superior electrochemical performance, with enhanced specific reversible capacity (∼1100 mAh g−1 at the specific current of 0.05 A g−1 after 100 cycles), excellent rate capability (more than 500 mAh g−1 even at the specific current of 1.1 A g−1) and good cycleability with little fading (∼97.6% after 100 cycles). The excellent cycling performance is associated with the loose Zn ferrite microsphere with numerous mesopores embedded into the carbon network, which can accommodate the severe mechanism strains and provides good electrical contact and conductivity. The superior electrochemical performance may facilitate ZnFe2O4 to be a promising alternative anode in lithium ion battery.
The effects of an Li-Al layer on the modified-Li anode based on solid state batteries are studied. The structure, surface morphology, and cyclic stability of the modified-Li anode are examined by X-ray diffraction spectroscopy, scanning electron microscopy, and electrochemical tests. Results show that interphase layer can prevent Li from reacting with Li1.5Al0.5Ge1.5(PO4)3 and displays a much better cycling stability compared with the bare-Li anode used in symmetric cells. The assembled solid state batteries with modified-Li anode and LiMn0.8Fe0.2PO4 cathode can deliver an initial discharge capacity of 153 mAh g−1 with good cyclic stability and rate performance at 50 °C. The reason for this is that the Li-Al alloy interphase layer can prevent localised Li enrichment, then suppress lithium dendrite growth, and the Li-Al layer on the anode possesses good stability in the presence of Li1.5Al0.5Ge1.5(PO4)3 powder and better interphase contact results between the anode and solid electrolyte in solid state batteries.
The effect of bath temperature on the electrochemical properties of electrolytic manganese dioxide (EMD) was studied. EMD was produced by anodic deposition from acidic aqueous solution of manganese sulfate at different bath temperatures in the range of 60–120°C. At temperatures above the boiling point of water, the electrolysis was carried out in an autoclave. The EMD produced at 120°C was of gamma type, identified by X-ray diffraction (XRD). Furthermore, the materials produced at 115 and 120°C were quality-controlled by cycling a sample as cathode mix in small size RAM-cells and by scanning electron microscopy. The results indicated an increase in cyclic charge/discharge performance and an improvement of crystallization conditions of EMD produced at elevated temperature when compared to data of commercially available γ-MnO2.
A low-cost hierarchical porous carbon (HPC) derived from pomegranate residues has been prepared via facile carbonization (at 600 °C, 700 °C and 800 °C) and activation, and applied as a sulfur host for lithium‑sulfur batteries. The rich protein in pomegranate residues provides nitrogen sources for the N-doped HPC. The influence of carbonization temperatures on the microstructure and performance of HPC has been investigated. In comparison to the HPC-700 and HPC-800, the HPC-600 sample has the highest BET surface area of 2064.32 m2 g−1 and pore volume of 1.12 cm3 g−1. When tested in LiS batteries, the as-prepared HPC/S-600 cathode with loading sulfur content of 71.54 wt% shows a high initial discharge capacity of 1010 mAh g−1 at 0.1C，and the reversible capacity retains 550 mAh g−1 after 500 cycles. The high cycling stability of HPC/S electrode is attributed to the synergistic effect of hierarchical porous structure and N-doping, which can provide strong physical and chemical confinement to sulfur and the soluble lithium polysulphides.
CO2 capture and conversion to fuels using renewable energy is being promoted as a climate change mitigation measure that reduces fossil fuel use by effectively recycling carbon. We examine this claim, first for a typical CO2 capture and utilization (CCU) system producing methanol (MeOH), and then for a generalized system producing fuels from fossil carbon. The MeOH analysis shows CCU to be an inferior mitigation option compared to a system with CCS producing the same fuel without CO2 utilization. CCU also is far more costly. The generalized analysis further reveals that the mitigation potential of CCU for fuels production is limited to 50% of the original emissions of the reference system without CCU. We further highlight that the main challenge to CCU cost reduction is not the CO2-to-fuel conversion step but the production of required carbon-free electricity at very low cost.
Comparisons between a LiPF6·PEO20 polymer electrolyte and a 1.5M LiPF6 liquid electrolyte in a 3D-microbattery of coated interdigitated current collector pillars is presented here, using Finite Element Analysis (FEA). Ionic transport in the electrolyte is modeled by the Nernst–Planck equation and electrode potentials by Ohm's law. Simulations were carried out in steady state. The height of the electrode pillars and the distance between them were systematically varied in the simulations to evaluate the effects on ionic transport in terms of concentration, concentration gradient and the minimum concentration in the electrolyte. The studies showed that the polarization in the electrolyte can be decreased by increasing the electrode pillar length, while increasing electrode distances led to a nonuniformity of the electrochemical activity. Indications of an optimum pillar length were also observed. Comparisons of the electrolytes showed that the polymer electrolyte was able to deliver a more uniform electrochemical activity for these cell designs, but not able to sustain as high currents as the liquid electrolytes. At the current density used (10A/m2), concentration polarization in the polymer electrolyte led to concentration deviations from the mean value of up to 60%.
“Dual-graphite” cells use graphite as intercalation host at both electrodes, where the energy storage mechanism is based on the intercalation of lithium ions into the negative and the intercalation of electrolyte anions into the positive electrode. In this contribution, the electrochemical intercalation of bis(trifluoromethanesulfonyl)imide (TFSI) anions from an ionic liquid-based electrolyte (Pyr14TFSI) into graphite was studied using ex situ and in situ X-ray diffraction. We prove that the TFSI intercalated graphite exists in a series of staged phases. As for this electrode material the discharge capacity can be strongly influenced by the cut-off potential and temperature, the stage transitions and compositions of the TFSI intercalated graphite were determined in dependency of different temperatures and cut-off potentials. From the experimental data, the periodic repeat distance of the graphite intercalation compound, the TFSI gallery height and the maximum stoichiometries of C n + TFSI− at these different conditions are calculated and discussed.
In smart home system (SHS), various IoT sensors are widely used for monitoring and security purposes. In order to detect fires, heat, potential disasters in early stage, and ensure the safety of electricity, real-time online condition monitoring of indoor power line is necessary. However, these monitoring sensors depend on batteries, either replaceable or rechargeable, which are less economical, have limited life time, are environmentally hazardous, and complex to replace. Herein, we present an indoor power line based magnetic field energy harvester (IPLEH), as a sustainable and maintenance free power supply for self-powered wireless monitoring sensors in smart home applications. The proposed IPLEH harvests energy from the magnetic field induced by a current carrying conductor without electrically contacting the conductor, that are easily available in indoor power line system. The IPLEH device consists of ferrite split-core which can be easily installed on the existing power lines without cutting or disturbing the power supply. The experiment results show that the proposed IPLEH can deliver an average power density of 14.67 mWcm−3 (average power of 105.24 mW under the optimum load resistance of 230 Ω). In addition, different sensors applications such as temperature, humidity, human motion, and plant health, which are driven by the IPLEH, are successfully demonstrated. The wide applicability of the IPLEH and the experimental results are promising for the development of sustainable energy harvesters, that can be practically implemented in self-powered wireless monitoring systems for residential, commercial and industrial buildings.
Oxidative stress and neuroinflammation are considered the major central events in the process of Parkinson’s disease (PD). Nrf2 is a key regulator of endogenous defense systems. New finds have contacted activation of Nrf2 signaling with anti-inflammatory activities. Therefore, the outstanding inhibition of neuroinflammation or potent Nrf2 signaling activation holds a promising strategy for PD treatment. Icariin (ICA), a natural compound derived from Herba Epimedii, presents a number of pharmacological properties, including anti-oxidation, anti-aging and anti-inflammatory actions. Recent studies have confirmed ICA exerted neuroprotection against neurodegenerative disorders. However, the underlying mechanisms were not fully elucidated.