batterydata/paper-abstracts huggingface dataset:
Three-dimensional hybrid structure with Ni3S2 nanorod arrays as core material and NiCo hydroxide nanosheets as shell material is fabricated directly on flexible Ni foam. This hierarchical hybrid structure without any additives and binders behaves good electrochemical properties including a high specific capacitance of 1833.7Fg−1 (5.13Fcm−2) at a current density of 1Ag−1, good rate capability with 88.27% capacitance retention at a current density of 20Ag−1 and great cyclic stability. Moreover, an asymmetric supercapacitor (ASC) based on NiCo hydroxide@Ni3S2 hybrid structure on Ni foam as positive electrode and activated carbon as negative electrode is successfully assembled to further evaluate the electrochemical properties of the hybrid structure in a full-cell configuration. The ASC device also performs excellent electrochemical properties including a large potential window of 0–1.8V, a high specific capacitance of 215.8Fg−1 at a current density of 1Ag−1 and long-term cycling performance. In the meantime, the ASC device also delivers a high energy density of 92.8Whkg−1 at a power density of 1.0KWkg−1. These results suggest that 3D NiCo hydroxide@Ni3S2 hybrid structure has promising potential for use in high-performance supercapacitor.
Composites of spherical FePO4 and three-dimensional porous graphene (FP/3DG) were prepared through hydrothermal method, then the high-performed composites of three-dimensional graphene and LiFePO4 cathode materials (LFP/3DG/C) were prepared with the FP/3DG precursor by carbothermic reduction. Researches on the structure, morphology and electrochemical performance of the materials were carried out by XRD, SEM, Raman, EIS, CV and charge-discharge tests. The results show that the LFP/3DG/C composites exhibit excellent rate and cycling capabilities. At the current density of 0.2C, the first charge/discharge specific capacities were 167.2mAh/g and 165.1mAh/g, respectively, and the capacities remained 99.3% after 50 cycles; The discharge capacity was 144.7mAh/g and the capacity remains 99.6% after 100 cycles at 1C rate, while the discharge capacity was 91.3mAh/g at 10C rate. Compared with LFP/C materials, the LFP/3DG/C composites showed obvious improvement in rate capability and cycling stability.
Accurately predicting battery lifetime is difficult, and a prediction often cannot be made unless a battery has already degraded significantly. Here the authors report a machine-learning method to predict battery life before the onset of capacity degradation with high accuracy.
We describe a novel synchronous surface tailoring to form thin and uniform carbon coating layers and simultaneously induce an in-situ phase transition from a layered to spinel-like phase on the surfaces of Li-rich layered oxide (LLOs) particles by the thermal decomposition of 2,3-dihydroxynaphthalene (DN). The Li2MnO3 component in pristine LLO is not affected during carbon coating, but the coordination numbers of the Co ions and the CoO bonds in the LiTMO2 phase are diminished during carbon coating, implying that the formation of a spinel-like phase in LLO after carbon coating begins at the LiTMO2 with little variation in the Li2MnO3. As a result, the optimized DN (0.2 wt%)-coated LLO cathode material shows superb electrochemical properties owing to the formation of uniform carbon coating layers and the layered-to spinel-phase transition on the surfaces of the LLO particles, which improves the surface stability, electronic conductivity, and Li-ion kinetics in the LLO.
Since, at the health system level, there is little research into the possible interrelationships among the various indicators of health, healthcare performance, non-medical determinants of health, and community and health system characteristics, we conducted this study to explore such interrelationships using the Canadian Health Indicators Framework.
Recently, lithium-ion batteries have become widespread as a source of power or energy for everything from portable electronics to electric vehicles. As a result, the consumption of lithium is rapidly increasing, accompanied by an increase in its price. This study reports the synthesis of a regenerable sodium-based lithium silicate solid sorbent that uses less lithium than Li4SiO4 solid sorbents. The regenerable sodium-based lithium silicate solid sorbent was prepared by mixing LiOH with a sodium silicate solution in a 2:1 M ratio, which steadily maintained its CO2 capture capacity during multiple cycles. In addition to Li4SiO4 present in the developed solid sorbent, we attribute CO2 sorption and regeneration to a new structure, namely Li3NaSiO4. Notably, the LONS2 solid sorbent exhibits a faster CO2 sorption rate than that of the Li4SiO4 sorbent. Moreover, the LONS2 solid sorbent containing both Li3NaSiO4 and Li4SiO4 phases has potential for CO2 capture at high temperature.
Multi-walled carbon nanotubes (MWNT) are evaluated as a conducting agent in a high-density cathode for a Li-ion cell. Cathodes of LiCoO2 with a density of up to 4.0gcm−3 are fabricated using alternate conducting agents of MWNT and conventional carbon black (Super P). An electrode containing MWNT (MWNT-cathode) is superior to one containing Super P (Super P-cathode) in terms of both high-rate (1C) performance and cycle-life. Results from ac impedance and scanning electron microscopy (SEM) studies indicate that the improved performance of the former electrode is due largely to the resilience of the MWNT aggregates that form conductive bridges between particles of the active material. These resilient bridges maintain intimate contacts between the particles even when the composite expands on cycling. By contrast, similar but rigid bridges of carbon black in the Super P-cathode are broken on cycling. Overall, it is found that MWNT is a good candidate conducting agent to replace Super P and other carbon blacks and hence develop a high-energy Li-ion cell.
One of the current challenges for application of PEM fuel cell is to find corrosion resistant, electrically conductive, light weight, cost competitive bipolar plate material. Low temperature carburization (LTC) of stainless steels is a novel, patented process by Swagelok Company. This paper addresses the corrosion resistance characteristics of LTC SS 316 for polymer electrolyte membrane fuel cell (PEMFC) bipolar plate applications. Corrosion properties of this material were studied using potentiodynamic and potentiostatic tests in simulated (1M H2SO4 +2ppm HF, 0.5M H2SO4, pH: 4.0, and 5% HCl+5% Na2SO4) PEMFC conditions. LTC SS 316 showed excellent corrosion resistance in these conditions compared to SS 316. The mechanism of anodic dissolution and general corrosion of LTC SS 316 was observed to be similar to SS 316 however the extent of LTC SS 316 corrosion was less. LTC SS 316 showed corrosion currents well below 16μAcm−2 in anodic and cathodic atmospheres under potentiostatic conditions. The potentiostatic current rapidly falls to ∼4.0 and ∼1.5μAcm−2 under anodic and cathodic conditions, respectively. LTC SS 316 was observed to form a thinner oxide layer as compared to SS 316 after 24h of potentiostatic testing. Moreover LTC SS 316 lowered the interfacial contact resistance by approximately 24% as compared to SS 316 after corrosion testing. Hence this study clearly states the performance advantage of using LTC SS 316 as bipolar plate material as compared to conventional materials.
In this work, novel nano/micro structure nitrates are reported for sodium storage for the first time. By using a facile solution route, carbon black (CB) and carbon nanotube (CNT) are introduced to incorporate with copper nitrate hydrate (Cu(NO3)2·2.5H2O) to form Cu(NO3)2·2.5H2O/CB and Cu(NO3)2·2.5H2O/CNT composites for high capacity sodium storage, respectively. Morphological and structural investigations show that CB or CNT coating does not obviously change the particle size and phase composition of Cu(NO3)2·2.5H2O, while, the electrochemical performance of Cu(NO3)2·2.5H2O is significantly improved by introducing CB or CNT as a conductive network. Moreover, carbon matrix can also provide a buffer for suppressing particle pulverization during sodiation/desodiation process. Especially for CNT, it builds a three-dimensional conductive network for active particles. As a result, Cu(NO3)2·2.5H2O/CNT exhibits higher reversible specific capacity and better cycling stability than bare Cu(NO3)2·2.5H2O and Cu(NO3)2·2.5H2O/CB. After 30cycles, Cu(NO3)2·2.5H2O/CNT can deliver a reversible charge capacity of 140.7mAhg−1 at a current density of 50mAg−1. This result demonstrates that CNT reinforced Cu(NO3)2·2.5H2O composite could be a probable anode material for sodium-ion batteries. Besides, the probable sodium storage mechanism in Cu(NO3)2·2.5H2O is also proposed by using various ex-situ analytical methods.
Sn/C composites with sub-10-nm-scale tin nanoparticles uniformly dispersed in a carbon matrices are believed to be excellent anode materials for high energy and power density lithium-ion batteries. However, it is difficult to incorporate high-capacity, active Sn into the carbon structures due to the hydrophobic nature of the carbon surface. Surfactants and/or templates are always required for uniform dispersion of active Sn, inevitably increasing the production cost and degrading the electronic conductivity. In this work, we reported a facile and scalable electrospinning technology to synthesize Sn quantum dots finely embedded in N-doped carbon nanofibers. The composite electrode exhibited a high reversible capacity of 887mAhg−1 at a current density of 0.1Ag−1 after 200 cycles, about 75% retention of the initial capacity. Moreover, it showed good rate capability even when cycled at 0.2Ag−1 about 685mAhg−1 after 500 cycles and 508mAhg−1 at 0.4Ag−1 after 200 cycles. The exceptional performance is supposed to benefit from the high electric conductivity of N-doped porous carbon nanofiber structures, which not only provides fast and versatile transport pathways for the electrolyte ions and electrons, but also simultaneously solves the major problems of pulverization, loss of electrical contact, and particle aggregation of Sn anode. Moreover, the short diffusion path for both electrons and ions provided by the ultrasmall Sn particles further improved the rate performance.
The entire structure and principle of a pendulum wave energy converter (WEC) are introduced, and the designs of the dual-medium pressuriser and the dual-stroke hydraulic system are emphasised. The entire system and the one-stroke system are modelled and simulated to verify the feasibility of the dual-medium pressuriser and the dual-stroke hydraulic system. The experimental data acquired from the semi-physical test rig are analysed and validate the energy transmission strategy described in this paper.
Nickel cathodes have been found to become deactivated under long-term polarization in the H2 evolution region during alkaline water electrolysis. The cause of deactivation was examined using steady state polarization and measurement of hydrogen permeation through nickel foil in 8 mol/l KOH at 70°C and 100 mA/cm2. The long-term (over 50 h) permeation behaviour was explained by formation and growth of a nickel hydride phase. The rise in hydrogen overpotential was ascribed to an increase of the hydrogen surface coverage on the newly formed hydride. The effect of an electrolyte additive (a vanadium salt) on the hydrogen overpotential and permeation rate was also investigated. Upon addition of dissolved V2O5, the permeation rate was found to increase quickly and then slowly decrease to a steady value close to that measured for hydride-free nickel. Meanwhile, the hydrogen overpotential was observed to recover back to nearly its initial value for fresh nickel. The exhibited behaviour was attributed to decomposition of the hydride phase, after deposition of a vanadium-bearing compound. The prolonged contact between Ni and V was proposed as the main reason for hydride decomposition. The addition of more vanadium had no further result on the hydrogen overpotential.
Calcium-ion batteries (CIBs) have been attracting attention as next-generation secondary batteries. On the other hand, there are many problems to be studied such as the choice of electrolytes and electrode materials. In this study, we investigate the influence of the presence of water in electrolyte on the Ca2+ insertion/extraction properties of α-V2O5. Electrochemical tests showed that the overvoltage gradually decreases as the amount of water increases. Structural and elemental analyses suggested co-insertion of H+ in the water containing electrolyte and although the co-insertion amount of H+ differs depending on the amount of water, there is not much change in overvoltage reduction. So, the influence of H+ co-insertion on electrochemical properties is considered to be small. Bulk structure analysis of the electrolyte suggested that hydration to Ca2+ and dissociation of the contact ion pair of Ca2+ and anion progressed with increasing the amount of water in the electrolyte. From the above, it was revealed that the presence of water in electrolyte caused a large change in its structure, which has an important effect such as a reduction of overvoltage on electrochemical properties.
A new electrochemical procedure for the electrocatalytic carboxylation of aromatic ketones with carbon dioxide in ionic liquid, 1-butyl-3-methylimidazolium tetrafluoborate (BMIMBF4), to α-hydroxycarboxylic acid methyl ester was investigated for the first time. The electrochemical behavior of acetophenone in BMIMBF4 was studied by cyclic voltammetry with a reduction peak at −1.9V (vs. Ag). The electrolyses experiments were carried out in an undivided cell under mild conditions without any toxic solvents, catalysts and supporting electrolytes, followed by addition of an alkylating agent, affording the α-hydroxycarboxylic acid methyl ester in a moderate yield (62%). The results showed that the yields were strongly affected by various factors: temperature, current density, charge passed, electrode material and substrate concentration. Moreover, the ionic liquid was successfully recycled for this reaction.
A novel alcohol fuel cell is constructed by using Fe3+ as the oxidation agent instead of the conventional O2. Various alcohols as the fuels are tested, including methanol, ethanol, n-propanol and iso-propanol. In this fuel cell, the anode catalysts tested are PdSn/β-cd-CNT, PdSn/CNT, Pd/β-cd-CNT, Pd/CNT and Pd/β-cd-C, prepared by using multi-walled carbon nanotube (CNT) and carbon powder (C), as well as β-cyclodexdrin (β-cd) modified CNT (β-cd-CNT) and β-cd modified C (β-cd-C), as the substrates to immobilize PdSn and Pd nanoparticles in glycol solvent. The as-synthesized PdSn/β-cd-CNT catalyst presents significantly higher electroactivity for alcohol oxidation than the conventional Pd/C catalyst. Fe3+ reduction reaction is carried out on the cathode made of carbon powder. The anolyte (alcohols in 1 mol L−1 NaOH) and catholyte (Fe3+ in 0.5 mol L−1 NaCl) are separated with a Nafion 117 membrane. Open circuit voltage (OCV) of the cell with the anode PdSn/β-cd-CNT is 1.14–1.22 V, depending upon the used alcohol. The maximum power densities with methanol, ethanol, n-propanol and iso-propanol fuels are 15.2, 16.1, 19.9 and 12.2 mW cm−2, respectively.
From the perspective of mobile users, the most considerable experiences are service delay and battery lifetime, both of which are closely related to the user state transition mechanism adopted in most mobile wireless systems. In this paper, the user state transition mechanism with more than simple two states (active/idle or on/off states) is modeled through Markov chain. Then, its performance is numerically analyzed with respect to the energy consumption and the activation delay by considering the bursty traffic attributes of mobile web services. As a result, we derive the energy–delay tradeoff curves, which show an achievable performance bound of the user state transition mechanism. The derived energy–delay tradeoff curve provides a guideline for network operators to suitably apply the user state transition mechanism so as to minimize the energy consumption of a mobile node while guaranteeing the delay requirement of the service.
LiMnPO4 has attracted massive interests due to its appropriate redox potential and higher theoretical energy density. Here, we present a strategy to transform common LiMnPO4 into dispersive, hierarchical, nanorod-like structure by vacuum immersion using anodic aluminum oxide templates. Owing to the unique hierarchical configuration, the resultant carbon-LiMnPO4 nanorods having high percentage exposed (010) facets, uniform carbon coating and large specific surface area, are very effective to keep the advantages as a fast charge/discharge lithium ion battery cathode. As a consequence, the high reversibility capacity of up to 156.8 mAh g−1 at 0.05 C and 91.7 mAh g−1 at 10 C is achieved. Meanwhile, it still retains 98.2% and 97.5% of the initial capacity after 100 cycles at 0.2 C and 1 C discharge rate, respectively, revealing an excellent cycling stability. This synthesis strategy provides a new design idea for preparing advanced electrode materials for lithium ion batteries.
One-dimensional porous materials have been regarded as a desirable material platform for designing advanced Li-ion batteries, supplying great advantages of 1D Li+ and electron transport pathways, large contact area between the electrode and electrolyte, and the buffer zone for accommodating the mechanical stress caused by repeated Li insertion/extraction. Herein, porous ZnMn2O4 nanowires were synthesized through a hydrothermal reaction and followed by a calcination process. The structure analyses indicated that the porous ZnMn2O4 nanowieres assembled by many tiny nanoparticles. As expected, the sample showed excellent electrochemical properties in term of high specific capacity, long cyclic stability and good rate capability. Porous ZnMn2O4 nanowires maintained a high reversible capacity of 869.5mAhg−1 at the current density of 500mAg−1 after 100 cycles. Even at high current of 4Ag−1, it still delivered a specific capacity of 345.4mAhg−1, which is closed to the theoretical capacity of graphite (372mAhg−1). These results imply the promising potential of the porous ZnMn2O4 nanowires in advanced LIBs.
Active façade systems incorporating solar thermal collectors currently offer very promising energetic solutions. From among the available systems, a simple solution is the unglazed heat collector for potential integration in low-temperature applications. However, when adopting system definitions, the modification of some design parameters and their impact has to be fully understood. In this study, the case of an unglazed collector integrated into a sandwich panel is assessed and a specific analysis is performed for a proper assessment of the influence of key design parameters. Based on that case study of the real built system, a CFD model is developed and validated and a parametric assessment is then performed, by altering the configurations of both the panel and the hydraulic circuit. In this way, the potential of each measure to harness solar energy can be evaluated and each parameter with its different level of impact can be highlighted, to identify those of higher relevance. A characterization of the real solution completes the study, by providing the efficiency curves and the total energy collected during the experimental campaign. The maximum estimate of the efficiency of a 6 m2 façade was within a range between 0.47 and 0.34 and the heat loss factor was between 4.8 and 7.5. The case study exercises reveal the real energy efficiency and solar production patterns. There was also an opportunity to consider significant improvements to increase the output of the active façade. The main conclusions concerned the different criteria that improved the definition of the system and greater comprehension of alternative designs that may be integrated in the underlying concept.
We tested the utility of acoustic tri-axial acceleration transmitters in combination with ethogram and respirometry studies to quantify the activity patterns and field metabolic rates of free-swimming bonefish (Albula vulpes) in the coastal waters of Eleuthera, The Bahamas. Bonefish were found to exhibit relatively low activity levels in the field with no evidence of diel patterns or inter-sexual variation. Low activity levels reported by the accelerometers reflected low swimming speeds and intermittent swimming behaviours (i.e., swim-then-drift) that maximized energy efficiency. Such behaviours were also observed when conducting ethograms on bonefish held in a large field mesocosm. Laboratory derived standard metabolic rates and maximum metabolic rates during recovery from exercise were combined with acceleration transmitter calibrations to determine that individual bonefish typically operate at between 40 and 60% of their estimated metabolic scope in the field. However, occasionally acceleration values in the field were indicative of high intensity bursting activity that exhausted the majority of their estimated metabolic scope (0.7% of all field observations exceed 90% of estimated metabolic scope). Data gathered in this study provide a critical starting point for the development of a bioenergetics model for bonefish which will ultimately lend clues into how fish make a living in tropical tidal flats environments. Given that this paper is one of the first to use transmitters rather than archival loggers to collect data on tri-axial acceleration on fish, we also discuss the opportunities and limitations of using this new technology for marine fisheries research.
Carbon is an economy and effective material for improving the electron conductivity of Li4Ti5O12, coating carbon on Li4Ti5O12 is commonly through the means of calcinating the mixture of titanium, lithium and organic compounds in an inert atmosphere, which needs a careful control to avoid the reduction of Ti4+ in Li4Ti5O12 by the in-situ formed carbon. In this work, a facile way is applied to fabricate carbon on Li4Ti5O12 by using filter paper to absorb the solution containing Ti(OC4H9)4 and LiAC with a calcination at 700 °C in air. The formation of carbon on Li4Ti5O12 mainly related with the swelling property of the crystalliferous region in cellulose fiber. TEM image shows Li4Ti5O12 particles have the average diameter about 100 nm, which are coated by a thin layer of carbon with the thickness around 5 nm, and Li4Ti5O12 particles connect with each other by carbon, forming porous fiber, which facilitates the transfer of electron and Li+. In comparison with Li4Ti5O12 synthesized by sol-gel method, Li4Ti5O12/C present superior rate capability with the discharge capacity of about 165 mAh g−1 at 0.2 C and 141 mAh g−1 at 20 C.