batterydata/paper-abstracts huggingface dataset:
A mechanically-stable non-aqueous proton-conducting gel polymer electrolyte that is based on methacrylate monomers, is considered here for application in solid-state type supercapacitors. An electrochemical cell using activated carbon as active materials and the new gel polymer electrolyte has been characterized at room temperature using cyclic voltammetry, galvanostatic charge–discharge cycle tests as well as impedance spectroscopy. The use of phosphoric acid ester (instead of phosphoric acid) as a proton donor has led to an increase of both the operation voltage window (up to 1.3 V) and the electrolyte ionic conductivity (on the level of an order of magnitude). The resulting double layer capacitance of the microporous activated carbon was found to be as high as 120 F g−1; even more important, the supercapacitor utilizing non-aqueous proton-conducting gel polymer electrolyte is well-behaved in the wide temperature range (namely, from −40 to 80 °C).
Porous graphitic carbons (PGC) are synthesized to be used in internal parallel hybrid devices. The hybrid devices are assembled with a LiFePO4 cathode, and an anode based on a mixture of PGC and Li4Ti5O12. Then the hybrid devices are characterized by galvanostatic charge/discharge, rate charge/discharge and cycle performance testing. The results show that PGC hybrid devices possess better performance than the commercial activated carbon hybrid device. Moreover, the internal parallel hybrid device with 25% PGC, denoted as T3P1F, exhibits an optimal performance with high energy density, high power density and stable cycling performance.
Rechargeable lithium-sulfur batteries are one of the most promising candidates for next-generation energy storage systems with high theoretical specific capacity and energy density, but there is some major challenge in the application of theirs. Among them, the main issue is the shuttle reaction caused by the dissolution of lithium polysulfides into the electrolyte. Recently, nitrogen-doped carbon materials are attracting attention as inhibitors for the shuttle reaction. However, according to our humble opinion, it is not easy to control the nitrogen doping configurations of nitrogen-doped carbon materials as wish. The nitrogen doping configurations of nitrogen-doped graphene are very similar to the structure of some organic compounds, especially metal-free phthalocyanine. From this, density functional theory calculations are performed for the bound configurations between lithium polysulfides and metal-free phthalocyanine to assess the availability of metal-free phthalocyanine as an inhibitor for the shuttle reaction. The results show that metal-free phthalocyanine has sufficient potential to be used as an anchoring material for lithium polysulfides.
Binary room-temperature complex electrolytes have been synthesized based on lithium perchlorate (LiClO4) and organic molecules with acylamino groups, including acetamide, ethyleneurea, 2-oxazolidinone (OZO), urea, methylurea (NMU) and 1,3-dimethylurea (DMU). Both LiClO4 and all organic molecules with acylamino groups are solid at room-temperature, but their mixtures at the proper molar ratio are liquid with a liquidus temperature about below 25°C characterized by differential scanning calorimetry (DSC). Infrared spectroscopic studies show that the organic molecules can coordinate with the Li+ cation and the ClO4 − anion via their polar groups (the CO and NH groups). Such strong interactions lead to the dissociation of LiClO4 and the breakage of the hydrogen bonds among the organic molecules, resulting in the formation of the complex systems. Electrochemical performances of the complex electrolytes are evaluated with ac impedance spectroscopy, cyclic voltammetry (CV), and in a test electric double layer capacitor (EDLC), respectively. The LiClO4–acetamide electrolyte at molar ratio 1:5.5 exhibits the highest ionic conductivity, 1.25×10−3 Scm−1 at 25°C and 11.5×10−3 Scm−1 at 80°C. The analysis for the CV behavior indicates that the electrochemical stability window of these electrolytes is above 3V. The results demonstrate that these complex systems are promising electrolyte candidates for supercapacitor and probably other electrochemical devices.
In this work, the prospects of available and new battery technologies for battery electric vehicles (BEVs) are examined. Five selected battery technologies are assessed on battery performance and cost in the short, medium and long term. Driving cycle simulations are carried out to assess the influence of the batteries on the energetic, environmental and economic performance of BEVs in the medium term. Well-to-wheel energy consumption and emissions of BEVs are lowest for lithium-ion batteries; 314–374 Wh km−1 and 76–90 gCO2eq km−1 (assuming 593 gCO2 kWh−1 for European electricity mix), compared to 450–760 Wh km−1 and 150–170 gCO2eq km−1 for petrol and diesel cars. The total driving costs are lowest for ZEBRA batteries (0.43–0.62 $ km−1). But, only if ZEBRA batteries attain a very low cost of 100 $ kWh−1 and driving ranges are below 200 km, BEVs become cost competitive to diesel cars. For all batteries, it remains a challenge to simultaneously meet requirements on specific energy, specific power, efficiency, cycle life, lifetime, safety and costs in the medium or even long term. Only lithium-ion batteries could possibly attain all conditions in the medium term. Batteries that do not contain lithium have best perspectives to attain low costs.
This work tries to study the problem of methanol crossover through the polymer electrolyte in direct methanol fuel cells (DMFCs) by developing new cathode electrocatalysts. For this purpose, a series of gas diffusion electrodes (GDEs) were prepared by using single-walled carbon nanotubes (SWCNTs) supported Pt–Pd (Pt–Pd/SWCNT) with different Pd contents at the fixed metal loading of 50 wt%, as bimetallic electrocatalysts, in the catalyst layer. Pt–Pd/SWCNT was prepared by depositing the Pt and Pd nanoparticles on a SWCNTs support. The elemental compositions of bimetallic catalysts were characterized by inductively coupled plasma atomic emission spectroscopy (ICP-AES) system. The performances of the GDEs in the methanol oxidation reaction (MOR) and in the oxygen reduction reaction with/without the effect of methanol oxidation reaction were investigated by means of electrochemical techniques: cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS). The results indicated that GDEs with Pt–Pd/SWCNT possess excellent electrocatalytic properties for oxygen reduction reaction in the presence of methanol, which can originate from the presence of Pd atoms and from the composition effect.
The interface resistance between Li x FePO4 and poly(ethylene oxide) (PEO)–Li(CF3SO2)2N (LiTFSI) was examined by AC impedance measurement of a Li x FePO4/PEO–LiTFSI/Li x FePO4 cell in the temperature range of 30–60°C. Four types of resistance, R0, R1, R2 and R3 were proposed according to analysis of the cell impedance using an equivalent circuit. The sum of R0 and R1 in the high frequency range is consistent with the resistance of the PEO electrolyte. R2 in the middle frequency range is related to lithium ion transport to an active point for charge transfer inside the composite electrode, and R3 in the low frequency range is considered to be the charge transfer resistance. The activation energy for R2 was affected by the thickness and composition of the electrode, whereas that for R3 was not.
The article presents a statistical model of mechanical degradation in the negative electrode of lithium ion batteries. During battery operation, nano-cracks nucleate and grow caused by the impact of diffusion-induced stress during Li-ion intercalation. Particle agglomeration is another mechanical effect that contributes to morphological changes. The presented model employs a population balance formalism to describe the propagation of the particle density distribution function in the electrode. A set of kinetic and transport equations accounts for structure-transforming processes at the level of individual particles. These processes alter the particle density distribution function, and cause changes in battery performance. A parametric study reveals the population of small particles and the width of the initial particle size distribution (PSD) as the main parameters that determine changes in electrochemical performance and capacity fade. The model is applied to experimental data in order to isolate and quantify the impact of various degradation mechanisms.
Due to the poor electric conductivity but the excellent catalytic ability for the oxygen reduction reaction (ORR), manganese dioxide in the α phase (denoted as α-MnO2) anchored onto carbon black powders (XC72) has been synthesized by the reflux method. The specific surface area and electric conductivity of the composites are generally enhanced by increasing the XC72 content while the high XC72 content will induce the formation of MnOOH which shows a worse ORR catalytic ability than α-MnO2. The ORR activity of such air cathodes have been optimized at the XC72/α-MnO2 ratio equal to 1 determined by the thermogravimetric analysis. By using this optimized cathode under the air atmosphere, the quasi-steady-state full-cell discharge voltages are equal to 1.353 and 1.178 V at 2 and 20 mA cm−2, respectively. Due to the usage of ambient air rather than pure oxygen, this Zn-air battery shows a modestly high discharge peak power density (67.51 mW cm−2) meanwhile the power density is equal to 47.22 mW cm−2 and the specific capacity is more than 750 mAh g−1 when this cell is operated at 1 V.
Obstructive sleep apnea hypopnea syndrome (OSAHS) is associated with neurocognitive impairment. We examined the role of the systemic inflammatory response, measured by high-sensitivity C-reactive protein (hsCRP) assay, and the effect of CPAP treatment on hsCRP and cognitive impairment in patients with OSAHS.
Poly(pyrrole-co-aniline) (PPyA) copolymer nanofibers were prepared by chemical oxidation method with cetyltrimethyl ammonium chloride (CTAC) as template, and the nano-sulfur/poly(pyrrole-co-aniline) (S/PPyA) composite material in lithium batteries was achieved via co-heating the mixture of PPyA and sublimed sulfur at 160°C for 24h. The component and structure of the materials were characterized by FTIR, Raman, XRD, and SEM. PPyA with nanofiber network structure was employed as a conductive matrix, adsorbing agent and firm reaction chamber for the sulfur cathode materials. The nano-dispersed composite exhibited a specific capacity up to 1285mAhg−1 in the initial cycle and remained 866mAhg−1 after 40 cycles.
The voltammetric behavior of the Ce(III)/(IV) half-cell reaction in various electrolytes containing 0.6M Ce was investigated on both pristine and metal-modified carbon paper (CP) electrodes at three different temperatures (25, 40 and 55°C) in order to find the most favorable electrochemical conditions. The pristine CP displayed robust electrochemical performance for up to 200 repetitive CV cycles while the Pt loaded electrode’s performance was stable for only 70 cycles, even though the latter exhibited a more reversible behavior, moving from a quasi-reversible to a reversible system (Dox. =4.0×10−6 cm2 s−1 and Dred. =2.5×10−6 cm2 s−1). The In and La metal modified electrodes did not show any improvement with regard to the kinetics or reversibility of the reaction. The addition of 1M H2SO4 to the base electrolyte enhanced the cerium reduction reaction by a factor of 3, (−7.2×10−3 Acm−2). The highest exchange current densities (jo ) were achieved at 40°C for the CP-Pt (1×10−3 Acm−2) attributable to the presence of the catalytic Pt. Elevated temperatures (40 and 55°C) improved D and ΔEp. while also the mass transport parameters a) dynamic viscosity (∼1.5mPa·s) and b) electrolytic conductivity (∼265mScm−1) of the Ce(III)/(IV) half-cell reaction. Overall, pristine CP and to a lesser extent CP-Pt demonstrated good stability with prolonged cycling and kinetics comparable with the ones of Pt and Pt based electrodes.
A gas–liquid interfacial synthesis approach has been developed to prepare SnO2/graphene nanocomposite. The as-prepared nanocomposite was characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, and Brunauer–Emmett–Teller measurements. Field emission scanning electron microscopy and transmission electron microscopy observation revealed the homogeneous distribution of SnO2 nanoparticles (2–6nm in size) on graphene matrix. The electrochemical performances were evaluated by using coin-type cells versus metallic lithium. The SnO2/graphene nanocomposite prepared by the gas–liquid interface reaction exhibits a high reversible specific capacity of 1304mAhg−1 at a current density of 100mAg−1 and excellent rate capability, even at a high current density of 1000mAg−1, the reversible capacity was still as high as 748mAhg−1. The electrochemical test results show that the SnO2/graphene nanocomposite prepared by the gas–liquid interfacial synthesis approach is a promising anode material for lithium-ion batteries.
This work, we are the first to discover the high-output current density of the triboelectric nanogenerator (TENG) using rice husks as a source material. The raw rice husks (RH) can be directly phase transited into the amorphous SiO2 (RHSiO2) structure with highly nanoporous fragments by the thermal annealing with additional acid hydrolysis process. The RHSiO2-TENG׳s configuration is designed by polytetrafluoroethene (PTFE) and RHSiO2 films, which are chemically and thermally more stable than the metallic film. The pore size around 20–40nm is widely distributed throughout the SiO2 fragments that possess rich Si–O–Si and OH stretching bonds with strong tendency of repulsing electron because the H atoms have an extremely low electron affinity, leading to the RHSiO2 film exhibits much lower electron affinity when compared with the commercial SiO2 nanoparticles. As a consequence, the area power density of the RHSiO 2 triboelectric nanogenerator (RHSiO2-TENG) reaches 0.84Wm−2 with a peak short-circuit current density of 5.7mAm−2. Such a short-circuit current density is almost among the highest reported value based on dielectric-to-dielectric mode triboelectric nanogenerators. Rice husk possess many advantageous traits such as their light weight, low cost, being environmentally friendly, high porosity, excellent robustness, exceptionally chemical and thermal stability for superior corrosion resistance, makes it a valuable material for industrial applications.
Worldwide forced displacement is increasing the demand in global health programming for health-related data collection methods that cut across broad ethnic and cultural differences. An interdisciplinary team leveraged consumer-based tablet technology to develop a novel survey application addressing barriers in literacy, numeracy, and respondent privacy in resettled refugee communities. The computer assisted personal interviewing (CAPI) innovation was piloted among 65 resettled refugees in Middle Tennessee, in the context of a survey of psychosocial wellbeing. Results showed the tablet-based CAPI application was an affordable, versatile survey method that increased accessibility without sacrificing respondent privacy.
Positive electrodes for Li-ion batteries based on Li[Li1/3–2x/3Ni x Mn2/3–x/3]O2 (0≤ x ≤0.5) compounds are of significant interest because of their ability to deliver reversible capacities exceeding 200mAhg−1. In this article we describe the examination of Li1.2Ni0.2Mn0.6O2 (x =0.2 in Li[Li1/3–2x/3Ni x Mn2/3–x/3]O2) samples by X-ray diffraction (XRD), high-resolution electron microscopy (HREM), scanning transmission electron microscopy (STEM), electron diffraction, X-ray energy dispersive spectroscopy (EDS), and electron energy loss spectroscopy (EELS). The studies were conducted on freshly prepared oxides, and on oxide electrodes that were electrochemically activated by cycling twice between 4.8 and 2.0V vs. Li+/Li. Rectangular and parallelogram shaped dot arrays with a spacing of 0.43nm observed in HREM and STEM images along the [ 1 0 1 ¯ 0 ] zone axis, as well as streaks at 1/3 n ( 1 1 2 ¯ 0 ) (n =integer) positions in corresponding electron diffraction patterns, indicated ordering of Li-ions in the transition-metal (TM) (0001) layers following several stacking sequences, bounded by stacking faults, along the c-axis. Chemical analysis by EDS and EELS showed that Mn, Ni and O were present in all portions of the samples examined; no evidence of elemental segregation was observed either within the grains or at grain boundaries. The Li ordering on TM planes was significantly weaker but still discernable upon electrochemical activation of the oxide samples.
Gas production and gas retention properties of doughs are pivotal to the manufacture of bread of good quality, but these properties are rarely measured directly in fermenting dough due to a paucity of suitable instrumentation. A digital image analysis-based method was used to measure the dynamic specific volume (DSV) of various chemically leavened dough systems. Sodium bicarbonate (1.4–4.2g per 100g of flour) in combination with equivalent neutralizing amounts of the leavening acidulants glucono-delta-lactone, potassium acid tartrate, adipic acid or sodium acid pyrophosphate consistently increased the specific volume of bread dough so that void fractions in the dough spanned between 5 and 67% at ordinary fermentation temperatures. The relationship between the specific volume of dough at the end of fermentation and the actual gas evolved (measured independently) was essentially linear and was characterized by a slope that provided a good index of the actual gas-trapping properties of dough. Therefore, the use of the DSV technique in conjunction with chemical leaveners offers the possibility of obtaining quantitative, real time information on the gassing capacity of the leavening system and the gas-holding capacity of the dough.
The Lithium–Sulfur battery is a promising high performance battery candidate for large-scale application on account of its high theoretical specific capacity. However, it has come up short on delivering long cycle life mainly due to the formation of soluble polysulfides, which results in the loss of active material during redox processes. In this study, we prepared three different graphene oxide based carbon hosts − graphene oxide (GO), thermally reduced GO (t-rGO) and dopamine-assisted chemically reduced GO (c-rGO) − and investigated their physical and electrochemical properties as a sulfur cathode. We found significant absorbance of polysulfides on the c-rGO host, which provided stable discharge capacity of 601mAhg−1 at 0.5C for up to 300 cycles. This stable cycling behavior is further identified by in-situ UV–vis spectroscopy and ex-situ X-ray photoelectron spectroscopy, confirming the minimization of polysulfide dissolution toward the electrolyte through the adsorption of polydopamine coating.
Mechanical chest compression (mCPR) offers advantages during transport under cardiopulmonary resuscitation. Little is known how devices of different design perform en-route. Aim of the study was to measure performance of mCPR devices of different construction-design during ground-based pre-hospital transport.
Graphene-based metal oxides are desirable as potential anode materials for lithium-ion batteries (LIBs) owing to their superior electrochemical properties. In this work, sandwich-structured graphene-metal oxide (ZnO, NiO) composites are facilely synthesized on a large scale through self-assembly of graphene oxide nanosheets and metal ammine complexes, and then thermal decomposition of the self-assembled products. ZnO or NiO nanoparticles with diameters of 5∼10nm are immobilized between the layers of graphene nanosheets, which may provide the space for accommodating the volume change of metal oxides during cycles, and highly improve the electronic conductivity of the composites. Accordingly, these sandwich-structured composites exhibit enhanced electrochemical performances compared to metal oxide particles or stacked graphene nanosheets. This facile synthesis method is very suitable for the large-scale production of three-dimensional graphene-based composites as high-performance anodes for LIBs.
In a previous study (Dronkers, 1996), stroke patients identified as having apraxia of speech (AOS), an articulatory disorder, were found to have damage to the left superior precentral gyrus of the insula (SPGI). The present study sought (1) to characterize the performance of patients with AOS on a classic motor speech evaluation, and (2) to examine whether severity of AOS was influenced by the extent of the lesion. Videotaped speech evaluations of stroke patients with and without AOS were reviewed by two speech–language pathologists and independently scored. Results indicated that patients with AOS made the most errors on tasks requiring the coordination of complex, but not simple, articulatory movements. Patients scored lowest on the repetition of multisyllabic words and sentences that required immediate shifting between place and manner of articulation and rapid coordination of the lips, tongue, velum, and larynx. Last, all patients with AOS had lesions in the SPGI, whereas patients without apraxia of speech did not. Additional involvement of neighboring brain areas was associated with more severe forms of both AOS as well as language deficits, such as aphasia.
Sodium ion battery (SIB) technology is a promising technology for energy storage systems. Due to the abundance of sodium in nature and lower cost, it can be a viable alternative to the current Lithium ion battery (LIB) technology. In this research article P2-type layered sodium ion transition metal oxide Na0.7Ni0.3Mn0.59Co0.1Cu0.01O2 cathode material was synthesized using a citric acid assisted sol-gel method. It provided a very good reversible discharge capacity and better capacity retention than the state-of-the- art SIB. XRD pattern confirmed the successful insertion of copper ions in the lattice structure of Na-Ni-Co-Mn layered oxide. This material exhibited a high reversible capacity of 150 mAh/gm vs Na+ as the counter electrode when discharged through the voltage window of 4–1.5 V. The lesser polarization loss during cycling of the proposed cathode material helped to retain 94% of its maximum discharge capacity even after 80 cycles.
The hard carbon is attractive for the Li ion battery because of its higher capacity than the theoretical value of 372Ahkg−1 based on the composition of stage 1 Li-intercalated graphite, LiC6. However, since the Li-doping reaction occurs at the potential of around 0V versus Li/Li+ reference electrode, it is often pointed out the possibility of Li metal deposition on the surface of anode. From the viewpoint of the safety, it may be a moot point. In the present study, 7Li NMR measurement was performed to estimate the degree of Li metal deposition on the surface of graphite and hard carbon anode. As a result, it is clarified that the Li metal deposition does not occur up to 110% over-discharge of the reversible capacity of hard carbon, whereas in the case of graphite anode, Li metal deposition occurred above 105% over-discharge of the capacity. From the 7Li NMR spectroscopy, the safety limit of hard carbon is rather superior to that of graphite.