batterydata/paper-abstracts huggingface dataset:
The charge transfer reaction is the fundamental reaction for rechargeable batteries. The energy landscape of this reaction depicts the equilibrium and kinetics of the electrochemical process. Typically, a Li-metal electrode is always covered by a thin layer of solid electrolyte interphase (SEI), forming a complex Li/SEI/electrolyte interface. In this paper, a new modeling framework was developed to predict the energy landscape of the lithiation/delithiation charge transfer reaction at a Li/Li2CO3/EC-electrolyte interface, with combined density functional theory (DFT) and tight-binding (DFTB) calculations. It was found that Li+ ions are much more energetically favorable to be dissolved in the electrolyte on a zero-charged Li-metal electrode, indicating that the SEI is a necessary kinetic barrier to prevent complete solvation of Li-metal into the electrolyte. During delithiation, Li+ ions would be stripped from the surface non-uniformly and form a large void on the Li-metal surface. During lithiation, it was demonstrated that the annihilation of Li+ ions and electrons occurs at the Li/SEI interface, for an idealized defect free SEI. Furthermore, at the experimentally defined zero voltage for Li+/Li0, the Li-metal surface is negatively charged (−0.62 ± 0.12 e nm−2) to maintain the electrochemical equilibrium. The electric field created by the negatively charged surface can reorient the electrolyte into an ordered structure, lower the Li+ ion desolvation energy barrier, and help the Li+ ion transport through the SEI. The charge transfer coefficient, α, in the Butler–Volmer equation was directly computed to be ∼0.22 from the simulated energy landscape, consistent with the experimental measurements. Thus, this model enables a bottom-up multiscale modeling approach for ion-transfer electrochemical reactions.
This work provides a method to help recover nickel, cobalt metals and some of their salts having market value from spent nickel-metal hydride batteries (SNiB). The methodology used benefits the solubility of the battery electrode materials in sulfuric or hydrochloric acids. The results obtained showed that sulfuric acid was slightly less powerful in leaching SNiB compared to HCl acid. Despite that, sulfuric acid was extremely applied on economic basis. The highest level of solubility attained 93.5% using 3N sulfuric acid at ⩽90°C for 3h. The addition of hydrogen peroxide to the reacting acid solution improved the level of solubility and enhanced the process in a shorter time. The maximum recovery of nickel and cobalt metals was 99.9% and 99.4%, respectively. Results were explained in the light of a model assuming that solubility was a first order reaction. It involved a multi-step sequence, the first step of which was the rate determining step of the overall solubility. Nickel salts such as hydroxide, chloride, hexamminenickel chloride, hexamminenickel nitrate, oxalate and nickel oleate were prepared. With cobalt, basic carbonate, chloride, nitrate, citrate, oleate and acetate salts were prepared from cobalt hydroxide Cost estimates showed that the prices of the end products were nearly 30% lower compared to the prices of the same chemicals prepared from primary resources.
The control of a direct methanol fuel cell (DMFC) operating under variable power conditions is important in the development of a commercially applicable device. Fuel cells are conventionally designed for a maximum power output. However variable load cycles can result in fuel cell operation under sub-optimal conditions. In this paper, a simple method of power management using a physical guard is presented. The guard can be used on the anode or cathode electrode, in the membraneless gap or in any combination. This design selectively deactivates specific active regions of the electrode assembly and enables the DMFC to operate at a constant voltage and current density at different absolute power conditions. The guard also serves to control excessive crossover during shutdown and low power operation.
The removal of metal ions from aqueous solutions by biosorption plays an important role in water pollution control. In this study, dried leaves and branches of poplar trees were studied for removing some toxic elements (cadmium, lead, and uranium) from aqueous solutions. The equilibrium experiments were systematically carried out in a batch process, covering various process parameters that include agitation time, adsorbent size and dosage, initial cadmium, lead and uranium concentration, and pH of the aqueous solution. Adsorption behavior was found to follow Freundlich and Langmuir isotherms. The results have shown that both dried leaves and branches can be effectively used for removing uranium, while only branches were found to remove lead and cadmium completely from the aqueous solution. The maximum biosorption capacity of leaves for uranium was found to be 2.3 mg g−1 and 1.7 mg g−1 and 2.1 mg g−1 for lead and cadmium on branches, respectively. In addition, the studied biomass materials were used in removing lead and cadmium from contaminated water and the method was found to be effective.
We tagged 12 adult Common Cuckoos (Cuculus canorus) with non-platform terminal transmitter (non-PTT) GPS-UHF telemetry at their breeding grounds in Hungary. One male and two female Cuckoos (one of them twice) were again observed in subsequent years, and GPS fixes documented their migration routes to and from Africa, as far south as Namibia. All four routes showed the species-typical clockwise loop migration. Although currently non-PPT GPS tracking with remotely downloadable data as an ornithological method is primarily suitable to map home ranges of birds, it could be a complement to PTT technology in migration research, especially for delivery of higher spatial accuracy.
Many studies have revealed the presence of compounds with genotoxic activity in drinking water by means of short-term mutagenicity tests. In this study, the influence of the different steps of surface water treatment on the mutagenicity of drinking water was evaluated. Four different types of samples were collected: raw lake water, water after pre-disinfection with chlorine dioxide, water after filtration on granular activated carbon, and tap water. Water extracts underwent a bacterial toxicity test (Microtox test) and different in vitro genotoxicity tests: a test with Salmonella typhimurium strains, a Saccharomyces cerevisiae test, the SOS Chromotest with Escherichia coli and the Mutatox test with Vibrio fischeri. The Microtox test revealed high toxicity in the treated water samples. The disinfection steps increased the toxicity: the Mutatox test confirmed these results and the Salmonella/microsome test at the highest doses showed toxicity that could conceal mutagenicity. The SOS Chromotest was positive in all treated water samples without metabolic activation. In the test with S. cerevisiae both toxicity and genotoxicity generally increased during the water treatment steps, especially in cells without induction of cytochrome P450.
ABSTRACT Overview The authors propose updated and revised nomenclature, definitions and classification for tooth surface lesions. Their objective is standardization, clarity and clinical utility for the dental practitioner. The article presents a schema of the pathodynamic mechanisms in the formation of tooth surface lesions—three basic physical and chemical mechanisms, their interactions and their dental manifestations. Conclusions and Clinical Implications The use of precise definitions will assist the practitioner in determining the etiology of various tooth surface lesions. Understanding the pathodynamic mechanisms and their many possible interactions, as set forth in the schema, will enable the practitioner to make an accurate differential diagnosis and to provide effective prevention and treatment. It also will assist dentists in communicating more effectively with their colleagues as well as with their patients. In addition, the schema helps identify areas in which future research is indicated.
The activating immunoreceptor NKG2D has seven known host ligands encoded by the MHC class I chain-related MIC and ULBP/RAET genes. Why there is such diversity of NKG2D ligands is not known but one hypothesis is that they are differentially expressed in different tissues in response to different stresses. To explore this, we compared expression patterns and promoters of NKG2D ligand genes. ULBP/RAET genes were transcribed independent of each other in a panel of cell lines. ULBP/RAET gene expression was upregulated on infection with human cytomegalovirus; however, a clinical strain, Toledo, induced expression more slowly than did a laboratory strain, AD169. ULBP4/RAET1E was not induced by infection with either strain. To investigate the mechanisms behind the similarities and differences in NKG2D ligand gene expression a comparative sequence analysis of NKG2D ligand gene putative promoter regions was conducted. Sequence alignments demonstrated that there was significant sequence diversity; however, one region of high similarity between most of the genes is evident. This region contains a number of potential transcription factor binding sites, including those involved in shock responses and sites for retinoic acid-induced factors. Promoters of some NKG2D ligand genes are polymorphic and several sequence alterations in these alleles abolished putative transcription factor binding.
Production technology for automotive lithium-ion battery (LIB) cells and packs has improved considerably in the past five years. However, the transfer of developments in materials, cell design and processes from lab scale to production scale remains a challenge due to the large number of consecutive process steps and the significant impact of material properties, electrode compositions and cell designs on processes. This requires an in-depth understanding of the individual production processes and their interactions, and pilot-scale investigations into process parameter selection and prototype cell production. Furthermore, emerging process concepts must be developed at lab and pilot scale that reduce production costs and improve cell performance. Here, we present an introductory summary of the state-of-the-art production technologies for automotive LIBs. We then discuss the key relationships between process, quality and performance, as well as explore the impact of materials and processes on scale and cost. Finally, future developments and innovations that aim to overcome the main challenges are presented.
Sodium iron hexacyanoferrate (Fe-HCF) is regarded as a potential cathode material for sodium-ion batteries (SIBs) due to its high specific capacity, low cost, facile synthesis and environmentally friendly. However, Fe-HCF always suffers from poor electronic conductivity, low crystallinity and side reactions with electrolyte, leading to poor rate performance, low coulombic efficiency and deterioration of cycling stability. Herein, we report a green and facile synthesis to encapsulate Fe-HCF microcubes with potassium nickel hexacyanoferrate (Ni-HCF). The core-shell Fe-HCF@Ni-HCF composite delivers a reversible capacity of 79.7 mAh g−1 at 200 mA g−1 after 800 cycles and a high coulombic efficiency of 99.3%. In addition, Fe-HCF@Ni-HCF exhibits excellent rate performance, retaining 60 mAh g−1 at 2000 mA g−1. The results show that Fe-HCF@Ni-HCF integrates the advantages of both Fe-HCF and Ni-HCF, making it electrochemically stable as cathode material for SIBs.
Results of molecular dynamics simulations of poly(ethyleneoxide) and poly(ethyleneoxide)–sodium iodide melts are presented. In particular we focus on the segmental motion of the polymer backbone. It is argued and verified that a unified atom model accounts adequately for the long time dynamics of the polymer segments in the pure PEO system. The mean square displacement of the segments displays a power law behaviour with respect to time 〈Δr 2(t))〉∼(Dt) α . The temperature dependence of the coefficient D can be described by a Vogel–Tamman–Fulcher (VTF) law at low temperatures. At higher temperatures Arrhenius behaviour is recovered. The self-intermediate scattering function F s(k, t) has been computed for the pure PEO-system and two PEO x –NaI systems with x=8.67 and x=27.8 respectively. The long time decay of F s(k, t) can be described accurately by a stretched exponent exp(−(t/τ k ) β k ), with a temperature and wavelength (k-) dependent relaxation time τ k . The exponent β k is independent of temperature and depends only weakly on k. The long wavelength behaviour of F s(k, t) can be explained in terms of the Gaussian approximation: F s(k, t)=exp(−k 2〈Δr 2(t))〉). This implies β k =α and τ k ∼k −(2/α) in the limit of vanishing wave-number k. Mode coupling models provide a suitable framework for the interpretation of F s(k, t). Addition of salt slows down segmental relaxation and stiffens the polymer backbone. Experimentally however the increase in relaxation time is much larger than in our simulations. We attribute the discrepancy to the neglect of manybody polarization effects in our force model.
The use of ionic liquid (IL) electrolytes promises to improve the energy density of electrochemical capacitors (ECs) by allowing for operation at higher voltages. Several studies have also shown that the pore size distribution of materials used to produce electrodes is an important factor in determining EC performance. In this research the capacitative, energy and power performance of ILs 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4), 1-ethyl-3-methylimidazolium dicyanamide (EMImN(CN)2), 1,2-dimethyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide (DMPImTFSI), and 1-butyl-3-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate (BMPyT(F5Et)PF3) were studied and compared with the commercially utilised organic electrolyte 1 M tetraethylammonium tetrafluoroborate solution in anhydrous propylene carbonate (Et4NBF4–PC 1 M). To assess the effect of pore size on IL performance, controlled porosity carbons were produced from phenolic resins activated in CO2. The carbon samples were characterised by nitrogen adsorption–desorption at 77 K and the relevant electrochemical behaviour was characterised by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy. The best capacitance performance was obtained for the activated carbon xerogel with average pore diameter 3.5 nm, whereas the optimum rate performance was obtained for the activated carbon xerogel with average pore diameter 6 nm. When combined in an EC with IL electrolyte EMImBF4 a specific capacitance of 210 F g−1 was obtained for activated carbon sample with average pore diameter 3.5 nm at an operating voltage of 3 V. The activated carbon sample with average pore diameter 6 nm allowed for maximum capacitance retention of approximately 70% at 64 mA cm−2.
5–10nm thin rod shaped LiMnPO4 nanoparticles are synthesized by an improved thermal decomposition method. The synthesis parameters such as the concentration of surfactants, reaction temperature and time, as well as the presence of a solvent play a critical role in the formation of spherical, thin or thick nanorods, and needle-shaped particles of LiMnPO4. A washing procedure to efficiently eliminate the surfactants attached to the surface of LiMnPO4 nanoparticles is presented, avoiding thermal treatment at high temperatures. A nanocomposite LiMnPO4 electrode provides a discharge capacity of 165mAh/g at 1/40C and 66mAh/g at 1C with only 10wt% of total carbon additive. The characteristics of as-synthesized and low amount of carbon coated LiMnPO4 are described as well as their electrochemical properties.
Abstract This chapter is intended to provide technical information about different items related to off-grid PV systems: from solutions (Pico PV, PV pump, residential, industrial and services), including PV hybrid systems (PV-diesel based on batteries), to analysis of the power converters implemented in those systems. In addition, other items are analysed, such as the design of stand-alone PV systems and their influence on application and user behaviour, measuring and assessing performance, case studies of stand-alone PV applications for rural electrification and international standardization related to off-grid PV systems.
Increased shade tolerance and a lower thermal optimum for photosynthesis may give silver beech a photosynthetic advantage over mountain beech in cloudy regions of New Zealand, and possibly the understory.
Dimethyl sulfite (DMS) is studied as an additive in lithium bis(oxalate)borate (LiBOB)/γ-Butyrolacton(GBL) electrolyte with LiCoO2 cathode and mesocarbon microbeads (MCMB) anode. Electrochemical performances of LiCoO2/DMS-electrolyte/Li and Li/DMS-electrolyte/MCMB half cells are studied by cyclic voltammetry, battery cycler, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Thermal behaviors of electrode–electrolyte coexisting systems are evaluated using a C80 micro-calorimeter. The electrochemical results show that the polarization of LiCoO2 is decreased and the capacity is improved with the addition of proper content of DMS. The XPS and SEM examination show that the presence of DMS decreases the decomposition of BOB anion and modifies the formation of SEI film on the surface of MCMB anode. The C80 micro-calorimeter analysis shows that the electrode materials with a LiBOB/GBL+proper DMS electrolyte begin to release heat at higher temperature and generate less heat than that with a common electrolyte. Therefore, using proper content (such as 20%) of DMS as an additive in LiBOB/GBL electrolyte is beneficial for the performance of Li-ion batteries.
The impact of elevated temperature charge–discharge cycling on thermal conductivity (K-value) of Lithium Ion Polymer (LIP) cells of various chemistries from three different manufacturers was investigated. These included high voltage (Graphite/LiCoO2:3.0–4.35 V), wide voltage (Si:C/LiCoO2:2.7–4.35 V) and conventional (Graphite/LiCoO2:3.0–4.2 V) chemistries. Investigation results show limited variability within the in-plane and through-plane K-values for the fresh cells with graphite-based anodes from all three suppliers. After 500 cycles at 45 °C, in-plane and through-plane K-values of the high voltage cells reduced less vs. those for the wide voltage cells. Such results suggest that high temperature cycling could have a greater impact on thermal properties of Si:C cells than on the LIP cells with graphite (Gr) anode cells we tested. This difference is due to the excess swelling of Si:C-anode based cells vs. Gr-anode cells during cycling, especially at elevated temperatures. Thermal modeling is used to evaluate the impact of K-value changes, due to cycles at 45 °C, on the cells internal heat propagation under internal short circuit condition that leads to localized meltdown of the separator.
The artificial sensory-substitution system can work like real human sensory tissue and participate in the perception of sensory-handicap patient. The power-supply unit is key factor for its wearable, low-cost and long-term application. Here, a new self-powered multi-perception electronic-skin has been presented as brain sensory receptor for sensory substitution of tactility, audition, olfaction, gustation and vision. The device directly outputs the triboelectric sensory signal into brain using human motion energy without external electricity power or battery, and actively involves in multi-perceptions. The sensing unit arrays act as both the power source and brain sensory receptor for tracking force trace, hearing words, smelling odor, tasting beverage and recognizing image. The mechanism can be attributed to the coupling of triboelectrification and surface effect. The device connecting to mouse brain at primary somatosensory barrel cortex can mimic the mouse perception and drive the mouse activities. This new approach can be applied to fabricating new self-powered sensory-substitution systems and multi-perception brain sensory receptor.
Mg0.5Ti2(PO4)3 having NASICON-lattice was prepared by sol–gel method and evaluated as a cathode material for magnesium cells. The crystalline phase could be successfully obtained after heating at 600°C. Electrochemical magnesium insertion from a propylene carbonate solution into this host was found possible and one Mg2+ ion could be accommodated per unit formula. However, the magnesium insertion process was under kinetic control of Mg2+ diffusion due to the low mobility of Mg2+ in this host.
Fish entrainment through turbine intakes is one of the major issues for operators of hydropower facilities because it causes injury and/or mortality and adversely affects population abundance. Entrainment reduction strategies have been developed based on the behavior of downstream migrating fishes, particularly diadromous species. However, knowledge of the behavior of migratory fishes has very limited application for reducing the entrainment of resident fishes, including several species that represent important recreational and aboriginal fishery resources in reservoirs. In this study, we used fine-scale acoustic telemetry and state-space modeling to investigate behavioral attributes associated with entrainment risk of resident adult bull trout (Salvelinus confluentus) in a large hydropower reservoir in British Columbia, Canada.
The development of high-performance cathode electrocatalysts in nonaqueous lithium-oxygen (Li–O2) battery is mainly restricted by high charge/discharge overpotentials. Based on first-principles calculations, we theoretically explore the application potential of BC3 and NC3 nanosheets as the suitable cathode electrocatalysts. By analyzing the stable adsorption configurations of LixO2y (x = 0–4, y = 0–2) intermediates on BC3/NC3, it is confirmed that oxygen reduction reaction (ORR) on BC3 follows four-electron pathway with (Li2O)2 as the discharge product, while for ORR on NC3, (Li2O2)2 is the discharge product following two-electron pathway. We then plot the corresponding free energy diagrams of charge/discharge processes and calculate the theoretical discharge and charge overpotentials ( η O R R and η O E R ) along the optimal reaction pathways. Our results show that both the η O R R and η O E R on BC3 are considerably low (0.21 V and 0.36 V), indicating that BC3 can serve as a high-performance cathode electrocatalyst. Meanwhile, the η O R R and η O E R on NC3 (0.37 V and 0.95 V) are comparable to previously reported materials following two-electron pathway (such as N-doped graphene), exhibiting practical values. Both the BC3 and NC3 nanosheets are stable enough for application in Li–O2 battery, and dimethyl sulfoxide (DMSO) isn't recommended as an organic electrolyte when BC3 works as the cathode catalyst.
Graphitized Carbon Nanofibers (GANFg) were dispersed with a certain amount of organic expander and used as additive for the negative plates of the Lead Acid Batteries (LABs). Due to the high aspect ratio of these fibers, they are thought to reach the percolation threshold inside the Negative Active Material (NAM) and create a conductive network which would improve the cycle life of the LABs working in Partial State of Charge (PSoC) conditions. These fibers were added at three concentrations (0.50, 0.20 and 0.10wt. %) and dispersed in a sodium lignosulfonate aqueous solution. Unformed negative plates of three mixtures were prepared, together with a NAM Control sample, and 2V/1Ah small lead acid cells were assembled for testing the electrical performance of the different mixtures (capacity, cold cranking ability, charge acceptance, negative polarization study, PSoC cycles and Cyclic Voltammetry (CV)). Continuous physicochemical analysis was carried out for the negative plates. As a result, Carbon Nanofibers were able to increase cell cycle life working in PSoC conditions and slightly improve the charge acceptance, but also raised the water loss. However, this gassing increase was lower for Carbon Nanofibers in comparison with other carbon materials used in flooded LABs.