batterydata/paper-abstracts huggingface dataset:
Negative electrodes containing SiO x were investigated as alternative negative electrodes to carbon for Li-ion batteries. The results obtained on the effect of binders and carbon additives on the electrochemical performance (i.e., reversible capacity, coulombic efficiency, charge–discharge rate capability) of the SiO x –graphite electrode and SiO x electrode are presented. SEM analysis that utilizes facilities for in situ and ex situ studies were applied to better understand the performance and cycle life of the SiO x -based electrodes. The SEM analysis clearly showed that the SiO x particles expand and contract during charge–discharge cycling, and that some of the particles undergo mechanical degradation during this process. The SiO x –graphite electrode with polyimide binder exhibited a stable capacity of 600mAhg−1 during high-rate charge–discharge from C/4 to 1C. These results suggest that the use of a flexible binder like polyimide and reasonably small SiO x particles (nano-particles) facilitates improved cycle life and higher rate capability.
The ionic conductivity of the Li2O–B2O3–SiO2 glass system was studied for potential application as a thin film electrolyte and compared with that of the Li2O–B2O3–P2O5 glass system. Among oxide glasses, these glass electrolytes are believed to be the most suitable for a thin film electrolyte due to the stable amorphous glass, its inertness to moisture and the ease of fabrication. The effect of spinodal decomposition on the ionic conductivity in the Li2O–B2O3–SiO2 glass system was also discussed. The ionic conductivity of phase-separated glass is dependent on the microstructure of the highly conductive phase. The structural analysis of the glass electrolyte was performed with various chemical compositions and the correlation to the ionic conductivity is discussed. The maximum conductivity of the Li2O–B2O3–SiO2 glass system is 2.4×10−8 Scm−1, which is lower than that of the Li2O–B2O3–P2O5 glass system by almost one order of magnitude. However, despite low conductivity, the Li2O–B2O3–SiO2 glass system is still believed to be a strong candidate for a thin film electrolyte since its glass formability and chemical stability are excellent compared to other glass electrolyte systems.
This paper proposes an integrated wind-photovoltaic-battery hybrid system that features a simple power management strategy, requires a lower number of power-electronic converters, and eliminates the need for dump loads. Thus, it is expected to offer a lower cost and higher efficiency, and to enable easier integration with distribution networks, as compared with a set of three stand-alone system. The power management strategy of the proposed hybrid system enables (1) rapid control of the wind and photovoltaic (PV) power outputs for tightly regulating the battery current, (2) off-grid operation with black-start capability, (3) grid-connected operation, and (4) safe transition from the grid-connected mode to the off-grid mode, and vice versa, without a need for communications with the host grid. Further, the proposed hybrid system is expected to have plug-and-play and power sharing capabilities and, therefore, suited for multi-generator remote electrification systems. The effectiveness of the proposed hybrid system is demonstrated through time-domain simulation studies in the PSCAD/EMTDC software environment.
Porous Co3O4 nanostructures with morphologies including hierarchical nanoflowers and hyperbranched nano bundles have been successfully synthesized by a controlled hydrothermal method and subsequent calcinations at higher temperature. Microscopic characterizations have been performed to confirm that mesoporous Co3O4 nanostructures are built-up by numerous nanoparticles with random attachment. The specific surface area and pore size of the nanoflowers have been found ∼51.2m2 g−1 and 12.6nm respectively. The nanoflowers as an anode materials for lithium-ion batteries (LIBs) demonstrate the higher initial discharge capacity of 1849mAhg−1 with a Columbic efficiency 64.7% at a rate of 50mAhg−1 between 0.01 and 3.0V. In addition, a significantly enhanced reversible capacity ∼980mAhg−1 is retained after 30 cycles. More interestingly, excellent high rate capabilities (∼ 960mAhg−1 at 250mAg−1 and ∼875mAhg−1 at 500mAg−1) are observed for porous flower-like structure. The improved electrochemical performance is attributed to the large specific surface area and porous nature of the flower-like Co3O4 structure which is more convenient and accessible for electrolyte diffusion and intercalation of Li+ ions into the active phases. Therefore, this structure can be considered to be an attractive candidate as an anode material for LIBs.
The Li2Fe1−x Ni x P2O7/C (x = 0.00, 0.02, 0.04, 0.06, 0.08, 0.10) composites were successfully synthesized for the first time by a conventional solid state route. The solid state reaction mechanism, crystal structure, morphology, and electrochemical performance of the samples are characterized in detail. The XRD results show that Ni2+ is incorporated in the lattice of Li2FeP2O7 and the monoclinic structure does not change after doping. Among all the samples, the Li2Fe0.98Ni0.02P2O7/C composite delivers the highest discharge capacity of 110.2 mAh g−1 at 0.025C, and possesses a capacity retention ratio of 90.1% after 100 cycles at 0.05C, demonstrating the best rate performance and cycle stability in the potential range of 2.0–4.5 V. Electrochemical impedance spectroscopy (EIS) results reveal that the Li2Fe0.98Ni0.02P2O7/C sample has a lower charge transfer resistance and a higher Li-ion diffusion coefficient compared to other samples. The results indicate Ni2+-doping in Li2FeP2O7/C can effectively enhance the electrochemical performance of this monoclinic compound, especially at a high charge/discharge rate.
Chronic fatigue is an underdiagnosed condition in children, particularly those with neuromuscular illnesses. The mechanism and treatment of chronic fatigue in this special population may differ from those of the adult population. More research is necessary to fully understand and best address the role of this problem in children with special health care needs.
In order to actually compensate “an irreversible capacity (i.e., an active lithium loss) ˮ usually observed at the 1st charging/discharging cycle of lithium ion batteries (LIBs), e.g., caused by a solid-electrolyte interphase (SEI) formation, a so-called pre-lithiation was applied to the graphite anodes of the laminated cell composed of three graphite anodes and three LFP (lithium iron phosphate) cathodes which were through-holed with the hole diameter of 20, 100 or 200 μm like the squares of a “Go-board”. The pre-lithiation was carried out (keeping an appropriate pre-lithiation charge amount) firstly by directly contacting the anodes with Li metal, which was previously introduced in the cell, to intercalate Li+ ions to them and then conducting the capacity balancing among the Li+-intercalated anodes by contacting them for a various period of time. It was found that in the cell composed of the through-holed anodes and cathodes with a given hole diameter the irreversible capacity can be significantly reduced by appropriately choosing the pre-lithiation charge amount and the capacity balancing time. Typically, in the anodes (the hole diameter: 20 μm) with the total capacity of 35 mAh, when the pre-lithiation charge amount was 3 mAh and the capacity balancing time was 12 h, no irreversible capacity could be observed actually, i.e., the 1st charge capacity was close to 100% and the expected stable charge/discharge capacities were obtained with the capacity retention of almost 100% in the continuous charge/discharge cycle. The results obtained demonstrate that the pre-lithiation of LIBs can be significantly improved using through-holed anodes and cathodes.
Metal oxides, such as SnO2, Fe2O3, CoO, Co3O4, NiO, CuO and MnO2 etc., are promising anode materials for lithium-ion batteries due to their high capacity and safety characteristics. However, the commercial utility of metal oxide anodes has been hindered to date by their poor cycling performance. Recent study shows that metal oxides with hollow nano/microstructures exhibit fascinating performance as anode materials for Li ion batteries. In this review, we first describe the current commonly used synthetic methods to create metal oxide hollow structures, and for each method, we also comment on its advantages and shortages compared with other methods. According to some typical examples and the following theoretical analysis, we show the promising use of hollow metal oxides as anode materials for lithium-ion batteries. Finally, the challenges and future developments of metal oxide hollow structures are further discussed.
Polymer electrolytes formed from high molecular weight poly(ethylene oxide) with dissolved LiN(CF3SO2)2 salt were obtained by casting from solution. The compositions ranging from 16:1 to 8:1 EO:Li molar ratio were studied by the X-ray diffraction and by impedance spectroscopy simultaneously with polarizing microscope observation. Crystallization processes and the resulting morphology of electrolytes were investigated in the temperature range from 85 to −20°C in various cooling and heating cycles. For all compositions, coexistence of crystalline phases of pure PEO and PEO6:LiTFSI complex was found. The results indicate that phase segregation plays a key role in the crystallization process. The amorphous phase acts like a reservoir of salt, which can be injected or drained by crystallizing spherulites of a defined composition. This interaction between pure PEO and PEO6:LiTFSI complex explains why effective crystallization process leading to a large decrease of conductivity can take place even in compositions close to the eutectic system. In such a system the concentration of salt in remaining amorphous phase can be very different from the initial composition of electrolyte. The ionic conductivity strongly depends on morphology of the electrolyte, which indicates a possibility of achieving high conductivity in the presence of the crystalline phases.
A novel vulcanized polymeric cathode (S@h-P) is prepared by an inexpensive, simple heat treatment of polyaniline with sulfur particles for lithium–sulfur batteries. Conventional lithium–sulfur batteries easily dissolve free polysulfides, which causes a long-term stability issue; therefore, modified separators and polysulfide absorbents are necessary. In this work, sulfur atoms form covalent bonds with aromatic rings of the polyaniline backbone, and so no free polysulfides from the novel cathode exist, as confirmed by XRD and DSC. From CV analysis, the S@h-P only exhibits lower-order polysulfide on the polymer backbone, which affects the charge-discharge profile during the cell test. S@h-P exhibits a satisfactory cyclic stability of 88% capacity retention after 200 cycles, and it offers the excellent rate performance of 55% capacity preservation at the current density of 10 A g−1 compared to 0.1 A g−1. Most interestingly, this polymeric cathode can function in a carbonated system, whereas conventional lithium–sulfur batteries can not. Accordingly, the novel S@h-P cathode can be employed to fabricate ultra-stable and high-performance lithium–sulfur batteries for practical application.
Li1+x (Ni0.37Mn0.63)1−x O2 (x =0.123, 0.111, 0.086, 0.070, 0.031) cathode materials were synthesized via coprecipitation of carbonates and the samples with long lifespan for lithium ion batteries were obtained through adjusting the content of lithium. Their crystal structure and electrochemical performance were characterized by means of powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), inductive coupled plasma (ICP), galvanostatic charge/discharge test and electrochemical impedance spectrum (EIS). The XRD data show that the materials can be indexed as a single α-NaFeO2 phase except the sample with x =0.031. The FESEM results indicate that the primary particles size increase with an increase of x value and the secondary particles retain the spherical morphology. The as-prepared sample with x=0.086 delivers the largest discharge capacity of 232.1mAhg−1 and a high initial efficiency of 81.8% at 0.2C in the potential range of 2.5–4.7V. Moreover, the better cycle performances are obtained for samples with x =0.123 and 0.111, and the capacity retentions are up to 89 and 81% of the first discharge capacity at 0.5C after 500 cycles, respectively.
Applied in a battery with a silicon-oxide (SiO) anode, a non-flammable triethyl-phosphate (TEP)-based electrolyte with fluoroethylene carbonate (FEC) improved the safety and energy density of the battery. This TEP:FEC-based battery demonstrated almost the same performance, namely, capacity retention of 78% after 250 cycles, as that of a flammable electrolyte such as an ethylene carbonate (EC)/diethyle carbonate (DEC)-mixed electrolyte (79%). Moreover, this non-flammable electrolyte significantly enhanced the safety of the battery. This improved performance and safety is attributed to the disappearance of the exothermic peak around 120–160 °C derived from the reaction between the electrolyte and charged anode. Accordingly, this non-flammable (TEP)-based electrolyte can enhance the safety of lithium-ion batteries.
As described in Materials World (July 2009), an online, noncontact, digital imaging technique to calculate local strain during electric resistance welding (ERW) metal pipe forming has been developed at the University of Alberta, Canada. Researchers hope to produce pipes with uniform properties by understanding the strain history around the circumference and correlating it to mechanical properties. “Reverse plastic deformation can result in reduction in yield strength (softening—due to the Bauschinger effect) at discrete locations around the circumference,” explains Barry Wiskel of the University of Alberta. “By understanding the relation between mill setup and ‘softening,’ corrective action can be taken.”
Thermically treated graphene oxides (TT-GOs) are synthesized at different temperatures, 100°C, 150°C, 200°C and 300°C in a reducing environment (20% H2/He) and investigated as electrode materials for vanadium redox flow battery (VRFB) applications. The treated graphene oxide-based electrodes are prepared by the wet impregnation method using carbon felt (CF) as support. The main aim is to achieve a suitable distribution of the dispersed graphene oxides on the CF surface in order to investigate the electrocatalytic activity for the VO2+/VO2 + and V2+/V3+ redox reactions in the perspective of a feasible large area electrodes scale-up for battery configuration of practical interest. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) are carried out in a three electrode half-cell to characterize the electrochemical properties of the TT-GO-based electrodes. Physico-chemical characterizations are carried out to corroborate the electrochemical results. The TT-GO sample treated at 100°C (TT-GO-100) shows the highest electrocatalytic activity in terms of peak to peak separation (ΔE =0.03V) and current density intensity (∼0.24Acm−2 at 30mV/s) both toward the VO2+/VO2 + and V2+/V3+ redox reactions. This result is correlated to the presence of hydroxyl (OH) and carboxyl (COOH) species that act as active sites. A valid candidate is individuated as effective anode and cathode electrode in the perspective of electrodes scale-up for battery configuration of practical interest.
In the present work, carbon composite of two dimensional porous thin carbon nanosheets hybrized with 3D freestanding hierarchical carbon foam (2D-CNs/3D-CF) was successfully fabricated for the first time via a facile impregnation and high temperature annealing strategy. The structure characterizations confirmed that 2D carbon nanosheets with a thickness of ∼8 nm and a plentiful pore channels were successfully assembled on the surface of 3D carbon foam skeleton. With such ultralight, flexible and porous 2D/3D hybrid carbon nanocomposite as active electrode material, a large specific surface area can be available and rapid electron transfer and ionic transport are facilitated. The electrochemical measurements demonstrated that the 2D-CNs/3D-CF-based supercapacitor presents an excellent specific capacitance of 364 F g−1 at 1 A g−1 and even a high specific capacitance of 321.86 F g−1 can be achieved at 10 A g−1 in 6.0 M KOH aqueous solution. Taking a comparison with the previously reported capacitor materials, the as-prepared hybrid carbon exhibited higher capacitance properties. Furthermore, the 2D/3D carbon-based supercapacitor exhibited an energy density of 47.30 Wh kg−1 at a power density of 0.84 kW kg−1 and the energy density can still retain 23.90 Wh kg−1 even when power density runs up to 80.11 kW kg−1 at a relatively high current density of 200 A g−1, demonstrating the superior capacitor performance and extremely high power density and energy density. Such novel carbon nanostructure with 3D freestanding hierarchical carbon foam hybrized with 2D porous carbon nanosheets may have promising application in energy storage devices.
The main objective of this work was to assess the cytotoxic activity of Au/Pt/ZnO nanoparticles synthesized using Arctium lappa extract against leukemia. The Au/Pt/ZnO nanoparticles obtained as a result of biological synthesis were characterized by UV-Vis, Scanning (SEM) and Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and Atomic Force Microscopy (AFM). The applied methods showed that the size of nanoparticles ranged from 10 to 40 nm. This work also assessed the cytotoxicity of Au/Pt/ZnO nanoparticles by means of MTT assay, and analyzed apoptosis as well as the influence of the cultivation time and concentration of Au/Pt/ZnO nanoparticles on the percentage of dead cells. The studies showed that the percentage of dead leukemia cells increased with the cultivation time and concentration of Au/Pt/ZnO nanoparticles. There was observed an increase in the percentage of cells in the G2/M phase, which suggests the stoppage of G2/M leading to cell death. The cytotoxicity of Au/Pt/ZnO nanoparticles determined by means of the MTT test indicated that the viability of leukemia cells practically disappeared when the concentration of the tested nanoparticles was 10 mol.
A facile approach to the surface reduced graphene oxide (rGO) modification of micro-nano structured vanadium oxides composites are developed as cathode materials of lithium ions batteries (LIBs) and supercapacitors (SCPs) for the first time. The as-prepared V2O5–rGO and VO2–rGO composites exhibit remarkably enhanced cycling performance when being used as cathode materials in LIBs and SCPs, respectively. The uniform coating of graphene around the surface of vanadium oxides ensures good close electrical contact, therefore higher specific capacity and enhanced cycling performance than pure VO2 and V2O5 electrodes. Meanwhile, the cycling performance enhancement and capacity decay mechanism are presented, which is not only important to design electrode materials in LIBs and SCPs, but also extendable to the design and fabrication of other functional materials for energy storage and transfer systems.
The paper discloses the influence of the temperature and electrolyte saturation of the active block (positive and negative plates and AGM separator) on the rate and efficiency of the oxygen cycle (OC) in valve-regulated lead-acid batteries (VRLAB). Applying steady-state cyclic linear sweep voltammetry and measuring the gas flow leaving the cell, the rate and efficiency of OC were measured at constant temperature and electrolyte saturation as a function of the negative plate potential. The obtained results show that at constant potential of the negative plate the rate of the OC depends slightly on temperature. However, the efficiency of the OC strongly depends on the temperature—the higher the temperature, the lower the OC efficiency. The experimental results for the influence of the electrolyte saturation on the rate and efficiency of the oxygen cycle show that the saturation is the main rate- and efficiency-limiting factor. Combining the gas diffusion approach, porosimetric analysis of the NAM and AGM separator and the recently proposed model of the reactions that take place during the operation of OC, the mechanism of the influence of the electrolyte saturation on the rate and efficiency of the oxygen cycle was elucidated. It was shown that the optimal saturation value is about 93%.
The risk factors of high repetition, high force exertions, and awkward postures have been recognized as increasing the risk of cumulative trauma disorders of the upper extremities in certain jobs and tasks. Measurement of the reactive forces associated with hand tool use, an important component of an ergonomic evaluation, can be difficult in the field. The forces associated with powered hand tools have been measured at the object being worked upon, but few instances of direct instrumentation of non-powered hand tools have been reported. A system for field measurement of manual tasks is presented. System configuration and performance characteristics are detailed as well as the development rationale, system capabilities and limitations.
A triboelectric nanogenerator (TENG) offers improved output power for enhanced performance and throughput at a low cost as a type of practical energy harvester. In this work, a novel method which enhances the output power with the aid of a nano-to-micro morphology and which reduces the fabrication cost via the simple process of the glass transition of a polystyrene (PS) substrate is introduced. The glass transition of the PS quickly produces the nano-to-micro morphology within 1min with only a heating process in an air environment. The pristine PS substrate was crumpled in a uniaxial or biaxial direction when heated to a temperature of 170°C. Thus, the throughput is notably increased without the use of complicated fabrication processes or high-level equipment. The power enhancement effects of the proposed TENG were characterized. Under the optimized condition, the fabricated nanogenerator showed a fourfold increase in both the open-circuit voltage and short-circuit current due to the fourfold enhancement of the surface charge density arising from the crumpled structure compared to a control device without a nano-to-micro structure on the PS substrate. In this case, 160 serially connected light-emitting diodes (LEDs) were successfully illuminated with the optimized device, which was 2cm by 2cm in size.
Most reactive mobile ad hoc network (MANET) routing protocols such as AODV and DSR do not perform search for new routes until the network topology changes. But, low node mobility does not affect the MANET connectivity and the same routes may be used for a long time. This may cause concentration of traffic on few mobile stations (MSs), which results in congestion and hence longer end-to-end delay. In addition, continuous use of MSs may cause their battery power to get exhausted rapidly. Expiration of MS energy causes disruption of connections traversing through the MSs and could generate many simultaneous new routing requests. Therefore, we propose a load balancing approach called Simple Load Balancing Approach (SLBA), which can be transparently added to any current reactive routing protocol such as AODV and DSR. SLBA minimizes the traffic concentration by allowing each MS to drop RREQ or to give up packet forwarding depending on its own traffic load. Meanwhile, MSs may deliberately give up forwarding packets to save their own energy. For encouraging MSs to volunteer in forwarding packets, we introduce a reward scheme for packet forwarding, named Protocol-Independent Fairness Algorithm (PIFA). We compare the performance of AODV and DSR with and without SLBA and PIFA. Simulation results indicate that SLBA can distribute traffic very well and improve the MANET performance. PIFA is also observed to prevent MANET partitioning and any performance degradation due to selfish nodes.