batterydata/paper-abstracts huggingface dataset:
In this paper, a novel silica sol conductor SiO2(Li+) was synthesized from tetraethylorthosilicate (TEOS) and γ-(2,3-epoxypropoxy) propyltrimethoxysilane via sol–gel hydrolysis followed by neutralized with lithium hydroxide. The prepared SiO2(Li+) were incorporated into poly(vinylidene fluoride) (PVdF) by standard solution-casting technique coupled with phase inversion process to fabricate a composite microporous membrane. Then the resultant composite microporous gel polymer electrolyte (CMGPE) was obtained by simply immersing the dried composite microporous membrane into liquid electrolyte and being gelled. The physicochemical properties of the CMGPEs were characterized by FTIR, DSC, XRD, TG, stress–strain response and electrochemical measurements. They exhibit a higher porosity and a higher electrolyte uptake with a proper addition of SiO2(Li+), while, the degree of crystallization of composite microporous membranes decrease with it. In addition, the ionic conductivity of CMGPEs can also be enhanced by vast amount of Li+ ions on the added SiO2(Li+). When the content of SiO2(Li+) was 5wt%, ionic conductivity of the CMGPEs reached to 10−3 Scm−1 order of magnitudeat at room temperature and its electrochemical stability window was 5.2V. A proper content of SiO2(Li+) in PVdF-based membrane makes it a potential candidate for application as polymer electrolyte in devices.
Nanoporous hard carbon microspheres (NHCSs) were prepared by combination of microemulsion and polymerization methods and using phenolic resin (resol) as precursor and ethanol and ethylene glycol (EG) as solvent and soft template, respectively, followed by carbonization process. Using different amounts of EG resulted in NHCSs with different crystalline structure, surface area and pore volumes, and Li ion storage capacity, as evidenced by physical and electrochemical measurements. Higher and lower polymerization rates were also tested on the starting resol solution with composition which led to the NHCS with the highest surface area and Li ion storage capacity. The sample polymerized at higher rate had the highest surface area and pore volume, as well as the best Li ion storage performance in terms of capacity and rate capability. for all of the NHCSs, the specific surface area and Li ion storage capacity were well correlated, and a good correlation was observed between total pore volume and rate capability. Furthermore, acceptable correlations were found between Li ion storage capacity and either surface area or microstructure of the NHCSs.
Ni-rich layered oxides are regarded as the promising candidate for high energy density lithium-ion batteries owing to the high specific capacity. However, Ni-rich layered oxides suffer a rapid capacity fade, which is related to the undesirable structure evolution during cycling. Herein, an in-situ surface modification strategy by using Al2O3 nanofibers as electrolyte additive is adopted to enhance the crystallographic, morphological, component, and electrochemical stability of LiNi0.88Co0.09Al0.03O2 during cycling at both the particle and electrode level. The coating layer can be in-situ formed on the cathode surface after injecting the functional electrolyte into the cell. The integrated spherical morphology of secondary particles on the modified cathode is maintained during cycling without harmful microcracks. In the meantime, the coating layer protects the cathode from HF corrosion during cycling, which can reduce the dissolution of transition-metal ions and insure relatively uniform spatial distribution of the constituents across the cathode as detected by laser-induced breakdown spectroscopy (LIBS). Consequently, the modified cathode shows the improved stability with the high initial capacity of 198.1 mAh g−1 and good capacity retention after 800 cycles at room temperature. Moreover, the modified cathode also exhibits promising performance at higher operating temperature (55 °C) or higher charge potential (4.6 V).
We present a complete testing environment for the parallel performance characterization of biofuel cells. Besides rapid-assembly electrode fixtures and an aseptic electrochemical reactor, it comprises a 24-channel electrical testing system that bridges the gap between simple load resistors and costly multi-channel potentiostats. The computer-controlled testing system features active current control to enable the forced operation of half-cell electrodes, whereas galvanic isolation between individual channels ensures interference-free operation of multiple fuel cells immersed in a common testing solution. Implemented into the control software is an automated procedure for the step-wise recording of polarization curves. This way, performance overestimation due to a too fast increase in load current can be circumvented. As an applicational example, three abiotically catalyzed glucose fuel cells are characterized simultaneously in a common testing solution. Complete disclosure of the electrical system (incl. printed circuit board layout, control software, and circuit diagrams) in the online supplementary material accompanying this paper allows researchers to replicate our setup in their lab and can serve as inspiration for the design of similar systems adapted to specific requirements.
Aspect-based sentiment classification aims to predict the sentiment polarity of specific aspects appeared in a sentence. Nowadays, most current methods mainly focus on the semantic information by exploiting traditional attention mechanisms combined with recurrent neural networks to capture the interaction between the contexts and the targets. However, these models did not consider the importance of the relevant syntactical constraints. In this paper, we propose to employ a novel gated graph convolutional networks on the dependency tree to encode syntactical information, and we design a Syntax-aware Context Dynamic Weighted layer to guide our model to pay more attention to the local syntax-aware context. Moreover, Multi-head Attention is utilized for capturing both semantic information and interactive information between semantics and syntax. We conducted experiments on five datasets and the results demonstrate the effectiveness of the proposed model.
In this work, deoxyribonucleic acid (DNA)-wrapped multi-walled carbon nanotubes (MWCNTs), denoted as CNT@DNA, were successfully assembled through a facile sonication treatment. By using the as-obtained CNT@DNA as template, a NiCo2O4-CNT@DNA composite with anchored NiCo2O4 nanoparticles was fabricated by coating via in situ precipitation. The nanostructures of the as-synthesized samples were examined via powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) techniques. Subsequently, the NiCo2O4-CNT@DNA and NiCo2O4-CNT (prepared without DNA) samples were used as cathode materials to fabricate supercapacitors with high capacitive performance. The results of electrochemical tests show that the NiCo2O4-CNT@DNA electrode exhibits a high specific capacitance of 760.0 F/g at 5 mV/s, which is higher than that of the NiCo2O4-CNT electrode. The NiCo2O4-CNT@DNA electrode displays a capacitance retention of 96.2% after 5000 cycles at the current density of 5 A/g. Moreover, a NiCo2O4-CNT@DNA//activated carbon (AC) asymmetric supercapacitor, prepared using NiCo2O4-CNT@DNA and activated carbon as the positive and negative electrodes, respectively, shows a specific capacitance of 223.7 F/g and a maximum energy density of 69.7 Wh/kg at a power density of 373.9 W/kg. The NiCo2O4-CNT@DNA//AC asymmetric supercapacitors, integrated in series, powered 5 mm red, yellow, and green light-emitting diodes (LEDs). The above results demonstrate that the novel NiCo2O4-CNT@DNA composites can be promising candidates as electrode materials for high-performance supercapacitors in future applications.
The modeling of Lithium-ion batteries usually utilizes discrete-time system identification methods to estimate parameters of discrete models. However, in real applications, there is a fundamental limitation of the discrete-time methods in dealing with sensitivity when the system is stiff and the storage resolutions are limited. To overcome this problem, this paper adopts direct continuous-time system identification methods to estimate the parameters of equivalent circuit models for Lithium-ion batteries. Compared with discrete-time system identification methods, the continuous-time system identification methods provide more accurate estimates to both fast and slow dynamics in battery systems and are less sensitive to disturbances. A case of a 2nd-order equivalent circuit model is studied which shows that the continuous-time estimates are more robust to high sampling rates, measurement noises and rounding errors. In addition, the estimation by the conventional continuous-time least squares method is further improved in the case of noisy output measurement by introducing the instrumental variable method. Simulation and experiment results validate the analysis and demonstrate the advantages of the continuous-time system identification methods in battery applications.
Lead electrodeposited carbon foam (LCF), whose substrate was made from pitch by a template method, was investigated as possible positive current collectors for lead acid batteries. Scanning electron microscopy, cyclic voltammetry, and galvanostatic charge–discharge tests were employed to characterize the effect of the proposed collector on the structure and electrochemical properties of the positive active material (PAM). The LCF with uniform and dense lead coating shows the similar electrochemical characteristics to metallic lead in the voltage range where the positive electrodes of lead acid batteries operate. The LCF and lead slices were used as the positive current collectors to equip lead acid batteries, respectively. Comparative charge–discharge tests show that a battery equipped with a LCF collector exhibits higher PAM utilization efficiency and longer cycle life, for LCF can provide large specific surface area which is beneficial to electrochemical reactions and PAM adhesion. In addition, a light lead acid battery with a LCF positive current collector and a carbon foam negative current collector was made and tested for the first time. It deserves systematic industrial study in the future.
The development and utilization of biomass materials for high-performance energy storage electrode materials that meet the urgent need for green and sustainable development strategies are required. In this study, we developed a simple thermal treatment method for the formation of porous carbon (PC) from loofah sponge. An asymmetric supercapacitor was then assembled depending on the loofah sponge-derived PC@MnO2 and N-doped PC, providing high energy and power density than MnO2. The working voltage of the designed asymmetric device could reach 1.8V and exhibited excellent performance such as a high capacitance of 78.2Fg−1 at a current density of 1Ag−1 in 1.0M Na2SO4 aqueous electrolyte, a relatively high energy density of 34.7Whkg−1 and power density 26.8kWkg−1. In addition, the device exhibited good electrochemical stability, with approximately 91.2% retention of initial specific capacitance after 2000cycles. The asymmetric supercapacitor represents an exciting direction for enhancing the electrochemical performance of supercapacitors and designing next-generation high-performance energy storage devices.
In this paper, we leverage a 10-wave election panel to examine the relative and dynamic effects of voter evaluations of Bush, Palin, Biden, McCain, and Obama in the 2008 presidential election. We show that the effects of these political figures on vote choice evolves through the campaign, with the predictive effects of President Bush declining after the nominees are known, and the effects of the candidates (and Palin), increasing towards Election Day. In evaluating the relative effects of these political figures on individual-level changes in vote choice during the fall campaign, we also find that evaluations of the candidates and Sarah Palin dwarf that of President Bush. Our results suggest a Bayesian model of voter decision making in which retrospective evaluations of the previous administration might provide a starting point for assessing the candidates, but prospective evaluations based on information learned during the campaign helps voters to update their candidate preference. Finally, we estimate the “Palin effect,” based on individual-level changes in favorability towards the vice-presidential nominee, and conclude that her campaign performance cost McCain just under 2% of the final vote share.
We present CARE, a context-aware tool for nurses in nursing homes. The system utilises a sensors infrastructure to quantify the behaviour and wellbeing (e.g., activity, mood, social and nurse interactions) of elderly residents. The sensor data is offloaded, processed and analysed in the cloud, to generate daily and long-term summaries of residents’ health. These insights are then presented to nurses via an Android tablet application. We aim to create a tool that can assist nurses and increase their awareness to residents’ needs. We deployed CARE in a local nursing home for two months and evaluated the system through a post-hoc exploratory analysis and interviews with the nurses. The results indicate that CARE can reveal essential insights on the wellbeing of elderly residents and improve the care service. In the discussion, we reflect on our understanding and potential impact of future integrated technology in elderly care environments.
Al-doped β-Ni(OH)2 nanosheets are prepared by a simple hydrothermal process onto nickel foam by using a mixed aqueous solution of nickel nitrate, aluminum nitrate and ammonia. Their structure and surface morphology are studied by using X-ray diffraction analysis, energy-dispersive X-ray spectroscopy and scanning electron microscopy. The SEM images show changes in the microstructure of β-Ni(OH)2 by the addition of Al. The XRD results show that the α-phase Ni(OH)2 appeared by the addition of Al. The effects of Al content on the electrochemical behaviors of β-Ni(OH)2 are investigated by cyclic voltammetrys, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results show a drastic improvement in the capacitive characteristics of β-Ni(OH)2 with a specific capacitance increase from 941.7 to 2122.6 F g−1 by the addition of just 3.4 mol% Al. This work suggests that the as-prepared Al0.034Ni0.966LDH electrode has a promising future as higher charging/discharging rate materials for pseudo-supercapacitors.
Novel binary electrolytes based on ionic liquid (N-butyl-methyl piperidinium bis(trifluoro-methylsulfonyl)imide, PP14-TFSI) and sulfone (tetramethylene sulfone, TMS) have been prepared and examined for use in lithium-ion batteries. The addition of sulfone is expected to improve the lithium salts solvability, ionic conductivity and electrode compatibility of the ionic liquid greatly. More importantly, the addition of sulfone is not expected to deteriorate the peculiar properties of the ionic liquid, such as the wide electrochemical window and non-flammability. Experimental results have shown that the reversible discharge capacities of the Li/LiFePO4 half-cell, which contains a 0.5 M LiTFSI/(60%) PP14-TFSI/(40%) TMS mixed electrolyte at a current density of 0.05 C and 1 C, can reach up to 160 and 150 mAh g−1, respectively, which are much higher than the discharge capacity achieved using the pure ionic liquid electrolyte under the same conditions. Furthermore, lithium difluoro(oxalato)borate (LiDFOB) has been found to have positive effects on the battery performance of the mixed electrolytes. The 0.5 M LiDFOB/(60%) PP14-TFSI/(40%) TMS mixed electrolyte exhibits better compatibility with the Li1.2Ni0.2Mn0.6O2 cathode than conventional electrolytes, where an initial discharge capacity of 255 mAh g−1 is obtained and a stable capacity of above 230 mAh g−1 is retained after 30 cycles.
Efficient control of electrified powertrains requires accurate estimation of the power capability of the battery for the next few seconds into the future. When implemented in a vehicle, the power estimation is part of a control loop that may contain several networked controllers which introduces time delays that may jeopardize stability. In this article, we present and evaluate an adaptive power estimation method that robustly can handle uncertain health status and time delays. A theoretical analysis shows that stability of the closed loop system can be lost if the resistance of the model is under-estimated. Stability can, however, be restored by filtering the estimated power at the expense of slightly reduced bandwidth of the signal. The adaptive algorithm is experimentally validated in lab tests using an aged lithium-ion cell subject to a high power load profile in temperatures from −20 to +25 °C. The upper voltage limit was set to 4.15 V and the lower voltage limit to 2.6 V, where significant non-linearities are occurring and the validity of the model is limited. After an initial transient when the model parameters are adapted, the prediction accuracy is within ± 2 % of the actually available power.
Desiccant material has been used in drying applications because of its low energy consumption, among other advantages. Desiccant material can produce hot and dry air that is beneficial for the drying process. The advantages of using desiccant material in a drying system include continuous drying even during off-sunshine hours, increased drying rate due to hot and dry air, more uniform drying, and increased product quality especially for heat-sensitive products. Some problems in desiccant system such as pressure drop in solid desiccant, carry over of liquid desiccant by air stream and low moisture adsorption capacity may be improved by optimization of the design of desiccant system. Numerous researchers have studied the low cost and low regeneration temperature of desiccant material, and the optimization of desiccant application to produce more competitive energy. The use of heat to regenerate desiccant material in a drying system has limitations in energy saving. However the use of low energy or free available energy such as solar energy and waste heat from industrial processes for regeneration of desiccant material will make the system more cost-effective. This paper presents several works on the regenerative method of the desiccant system and its application in the drying system for both solid and liquid desiccant materials.
Safinamide is a monoamine-oxidase-B inhibitor with peculiar features. At the dose of 100 mg/day, safinamide stimulates dopaminergic transmission and reduces glutamatergic transmission. Here, we investigated the effects of safinamide 100 mg on executive functions at the end of levodopa dose in fluctuating Parkinson’s disease (PD) patients. Thirty-two fluctuating PD patients were submitted at baseline (V1) to the UPDRS-III, the Frontal Assessment Battery (FAB) and the Stroop-Word-Color-Test (SWCT) at the end of levodopa dose. Safinamide was then added to the original therapy. After 12 weeks of treatment, patients underwent the final visit (V2), including the UPDRS-III, the FAB and the SWCT with the same daily time schedule as V1. Treatment with safinamide was associated with significant increases of the total FAB score, SWCT-interference time score and UPDRS-III score. Within FAB subdomains, add-on with safinamide significantly increased motor programming and increased mental flexibility and inhibitory control scores. The results of this exploratory study show that add-on with safinamide improves executive functions at the end of levodopa dose in fluctuating PD patients. In particular, attention and inhibition of cognitive interference were significantly ameliorated by add-on with safinamide, suggesting increased modulatory performances of prefrontal cortical pathways. If confirmed by future research on larger cohorts and under controlled conditions, the present results may represent the basis for a novel indication for the use of safinamide in fluctuating PD patients.
Insulated polymer host and lithium salt need to be separately dissolved into organic solvents prior to assembly of lithium batteries, implying a large usage of organic solvents and the consequent disadvantages of poor thermal stability, flammability, and explosibility of the end products. Herein, a new generation of thermotropic ionic liquid crystalline lithium salt (LiBIB) with potential bilayer fast ion-conductive tunnels, having functionalities of both lithium salt and polymer host or electrolyte, is successfully synthesized. Molecular structure, thermal stability, ionic conductivity, electrochemical stability, and ion-conductive mechanism of the LiBIB are extensively assessed. The obtained LiBIB shows typical behaviors of both ionic liquid and liquid crystal. Melt point at 43 °C, much lower than that of traditional lithium salts like LiClO4 and LiPF6, and clear point of the LiBIB at 83 °C are both detected. Solid LiBIB salt shows better ionic conductivity (3 × 10−3 S cm−1) and electrochemical stability at room temperature in comparison with those of traditional lithium salts. Time-resolved and perturbation-correlation moving window 2D-COR FTIR results indicate that the high ionic conductivity of the LiBIB is mainly originated from the formation of fast ion-conductive tunnels, implying a promising application in solvent-free Li-ion batteries.
Triboelectric nanogenerators (TENGs) typically have very low outputs in terms of root-mean-square (RMS) values as the outputs are in the form of short duration pulses. In order to overcome this limitation, here we introduce multi-phase rotation-type TENGs (MP-TENGs). The rotator of the MP-TENGs consists of alternating components of PTFE and mono cast nylon, whereas the stator consists of PTFE with multiple back electrodes. Each electrode produces an output of the same frequency and amplitude, but of different regularly shifted phases. Consequently, the outputs from all the electrodes are full-wave rectified and superimposed, and the total output of the MP-TENGs is almost constant direct current (DC), unlike typical TENGs, with much higher RMS values. A 5-phase TENG has produced 380 V, 3.6 mA m−2, and 4.9 W m−2, and the current crest factor is dramatically decreased to 1.26. Finally, due to the almost constant DC output, the MP-TENGs successfully operate electronic devices and charge a battery.
Polyaniline (PANI) is electrochemically synthesized using agar gel as a template (Agar-PANI). The material characteristics and electrochemical behavior of the Agar-PANIs are compared with those of polyaniline synthesized by means of conventional methods (C-PANI). The electrochemical synthesis is monitored using the cyclic potential sweep (CPS) technique. The dependency of the total deposition charge on the number of cycles can be satisfactorily explained with a CPS parameter, n, and is consistent with scanning electron micrographs. The electrical conductivity and the bulk density of the Agar-PANI samples are 1.5Scm−1 and 1.53gcm−3, which are three orders and four times larger than those of the C-PANI samples, respectively. On the other hand, C-PANI and Agar-PANI have similar crystallinity. The capacitances of the Agar-PANIs are 200–500Fcm−3 at 5mHz and these electrodes would be adequate for high energy density devices. The accommodation of glutamate is 1.5×10−3 molcm−3 for the Agar-PANI, which is two orders of magnitude larger than when a polypyrrole electrode is used.