batterydata/paper-abstracts huggingface dataset:
The main challenge for the lithium/sulfur battery is the significant capacity decay over cycling, as the result of the diffusion of lithium polysulfide and volume/morphology changes of sulfur electrode. Porous graphene monoliths have been widely used to alleviate these problems with its confined frameworks of porous structures and strong mechanical property; however, bulk graphene materials were normally loosely packed, leading to the low utilization efficiency of pores and unsatisfactory frustration in suppressing polysulfide dissolution/shuttle owing to their large and highly open pores. Herein, we report the dense integration of sulfur and graphene (S-G) gel through the soft approach to prepare a compact sulfur cathode with dense but porous structure. The compact S-G structures could better increase the bonding between sulfur and graphene, immobilize sulfur and restrain the polysulfide diffusion within the more closed pores than loose counterpart, and thus achieve improved volumetric discharge capacities, high rate and long-term cycling performance.
A biomolecule-assisted hydrothermal process is developed to synthesize cobalt sulfide (CoS), in which l-cysteine is used as the sulfide source and directing molecule. By controlling the synthesis conditions, CoS nanospheres and nanowires can be assembled. The as-synthesized samples are characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) are used to study the effects of microstructure and morphology of the samples on their capacitance and conductivity. A specific capacitance, as high as 508Fg−1, is achieved for CoS nanowires. This is very competitive with the best supercapacitor material, RuO2 (720–760Fg−1), but its cost is remarkably lower than RuO2. Thus the nanowires are a promising material for low-cost, high-performance supercapacitors. This method could provide a universal green chemistry approach to synthesize other metal sulfides.
We present the “vanadium solid-salt battery” (VSSB), which has high energy density, is low cost, is easily recycled, operates at ambient temperature, and has no requirement for special solvents. The VSSB contains two types of vanadium solid salts that are supported on carbon felts with a minimal amount of hydrosulfuric acid added to moisten the ion-exchange membrane. The optimized VSSB shows a cell potential of 1.34V, excellent reproducibility for charging and discharging for nearly 100cycles, a high energy efficiency (87%) and a high energy density (77Whkg−1 at 5mAcm−2 using the carbon felt XF208). The energy density is enhanced by 250–350% compared with conventional vanadium redox-flow batteries.
In this rising field of portable electronics, all solid state thin film supercapacitors (ASSTFSs) have received tremendous courtesies due to their flexibility and high safety, which are considered as competitive candidates for energy power sources in flexible electronics. In present investigation, we demonstrate the first successful application of pseudocapacitive RuO2 in ASSTFS, exhibiting high capacitance, remarkable high-rate capability and long-term cycling stability. Nanocrystalline RuO2 thin films are developed on mesh like stainless steel substrate by facile chemical bath deposition (CBD) method at three different deposition temperatures. ASSTFSs were fabricated by simple process using two slightly separated RuO2 thin films well solidified in the H2SO4–polyvinyl alcohol gel electrolyte. Electrochemical studies of ASSTFS device was characterized by cyclic voltammetry, charge–discharge and impedance techniques. The highest specific capacitance of 234, 203 and 167Fg−1 for three RuO2 nanostructures was obtained. Further the device shows good stability after 1000 cycles. The non-ideal behavior of the supercapacitor was analyzed by impedance analysis. Additionally, the all-solid-state nature combined with superior electrochemical performance makes RuO2-based device an excellent candidate for power sources in portable electronics.
Implementation intention formation, which involves identifying triggers and linking them with coping strategies, has proven effective at reducing alcohol consumption in general populations. For the first time, the present study tested the ability of implementation intentions to reduce alcohol consumption among heavy drinkers and to explore potential neuropsychological mechanisms. At baseline, participants were randomized to form implementation intentions or to an active control group. There was a 5.7 unit (1 unit = 10 ml or 8 g ethanol) per week reduction ([95%CI 0.15, 11.19], p = 0.048) in alcohol consumption at 1 month follow-up among participants who formed implementation intentions, which was significantly more than controls F(1, 91) = 3.95, p = 0.048, a medium effect size (d = 0.47, Cohen, 1992). No significant differences in performance on the neuropsychological tasks were found between groups. The present study demonstrates for the first time that implementation intentions reduce alcohol consumption among heavy drinkers.
Interface engineering is one of the key strategies to modify the intrinsic electronic structures of catalysts and consequently improve the electrochemical activity of the oxygen reduction reaction (ORR) in the cathodes of the energy conversion devices such as fuel cells and metal-air batteries. Herein, we proposed the mixed-phase mullite (AxSm1−xMn2O5-δ, x = 0–0.5, A=Ca, Sr, Ba), prepared by facile one-step co-precipitation method, to catalyze the oxygen reduction reaction (ORR). The X-ray diffraction (XRD) spectra show that each mixture includes three phases, i.e., mullite SmMn2O5, O-deficient perovskite AMnO3-δ and MnOx. Atomic bonding interfaces are formed between SmMn2O5 and AMnO3-δ, based on the observations of the high resolution transmission electron microscopy (HRTEM). Among these different mixed-phase samples, we find that BaxSm1−xMn2O5-δ/C exhibits the best ORR catalytic activity with the half-wave potential ~ 0.79 V (vs. RHE) and the highest stability over 20,000 s. This performance can be ascribed to the largest charge transfer from BaMnO2.83 to SmMn2O5. Subsequently, partial Mn4+ in mullite SmMn2O5 phase are reduced to active sites Mn3+ to achieve the e g unit occupancy in the interfacial depletion region. In comparison with the reactions over pure-phase mullite SmMn2O5, these transferred electrons are involved into ORR and thus accelerate the proceeding. Our work thus provides insights into designing heterogeneous compound catalysts via interfacing engineering in the applications of the electrochemical oxygen reactions.
We describe the case of a patient with right hemisphere damage and left unilateral neglect. The patient was asked to draw from memory common objects, either with or without visual feedback. In the conditions without visual feedback the patient was either blindfolded or he made “invisible” drawings using a pen with the cap on, the drawings being recorded with carbon paper underneath. Results showed more neglect without than with visual feedback, contrary to previously published cases. This patient's pattern of performance may result from the contribution of a deficit of spatial working memory. Alternatively or in addition, the patient, who was undergoing cognitive rehabilitation for neglect, may have found easier to compensate for his neglect with visual feedback, which allowed him to visually explore the left part of his drawings.
We report an original setup using carbon nanotube matrices as supercapacitors where redox enzymes serve for continuous charging of the capacitors. High currents can be delivered under short pulse discharges. This supercapacitor/biofuel cell hybrid system remains stable for at least 40000 pulses of 2 mW.
The evolution of lithium-containing species on the surface of grains of 500nm LiFePO4 and 100nm carbon-coated LiFePO4 materials during the aging process in LiPF6 electrolyte has been followed using coupled 7Li MAS NMR, EIS (Electrochemical Impedance Spectroscopy) and XPS for materials synthesized with and without carbon coating. LiFePO4 undergoes surface reactivity upon immersion in classical LiPF6 electrolyte, although its open circuit voltage (∼3.2V) lies in the thermodynamical stability voltage range. The evolution of the NMR signal shows that the reaction of formation of the interphase is very slow as no evidence of passivation could be found even after 1 month of contact with the electrolyte. 7Li MAS NMR combined with XPS indicates that carbon coating has a strong protective role towards formation of surface species on the material and hinders iron dissolution at elevated temperature. Coupled NMR, EIS and XPS experiments showed that the surface of the material grains is not covered by an homogenous layer. Increasing the storage temperature from 25°C to 55°C promotes the formation of organic species on the surface, most probably covering inorganic species such as LiF, Li x PF y and LiPO y F z . No evidence of the formation of a resistive film is deduced from the evolution of EIS measurements. The interphase growth can accelerate the degradation of the electrochemical performance, leading to a loss of electrical contact within the electrode.
Due to the lack of highly efficient and low-cost oxygen reduction reaction/oxygen evolution reaction (ORR/OER) catalyst and alkaline anion exchange membrane (AEM), advanced rechargeable zinc-air batteries are largely hindered in many applications from wearable electronics to electric vehicles. Herein, a hybrid of porous Co3O4 anchoring on MnO2, then interpenetrating with CNTs (Co3O4/MnO2-CNTs) is synthesized via facile hydrothermal process, and an AEM (CS/EMImC-Co-EP/GO) employing semi-interpenetrating network structure is fabricated with a simple solution-casting method. The porous nanoparticles and chrysalis-like hybrid as well as strong bi-metallic coupling effect build highways and buffer zones for reactant and electrons transfer for ORR/OER. In addition, due to the competition of bottom Co atoms, the density functional theory (DFT) proves that the neighbor Mn sites (Mn1 and Mn2) of the MnO2(110) surface are evidently activated, which prompts the catalytic activity of hybrids by making the Mn1, Mn2 3d density of states move forward lower energy entirely. As a result, Co3O4/MnO2-CNTs exhibit superior ORR/OER activities with the low potential difference (ΔE) of 0.85 V and impressive performances in rechargeable aqueous zinc-air batteries (power density: 534 mW cm−2). Moreover, combining AEM integrated into rechargeable flexible all-solid-state zinc-air batteries and stack, the enhancement natures of wearable devices are achieved even under different bending angles benefiting from high hydroxyl anion conductivity and remarkable flexibility of AEM semi-interpenetrating network, which accelerates ion transport by the synergy of hopping and vehicle mechanisms. Furthermore, the flexible all-solid-state zinc-air batteries show excellent tolerance toxicity of CO2.
Reduced-order physics-based models of lithium-ion cells provide the opportunity for a battery-management system to define battery-pack operational limits in terms of cell internal electrochemical processes in order to mitigate degradation and to avoid failure modes. For these physics-based models to be relevant over the lifetime of the battery pack, they must somehow adjust to describe the internal processes accurately at every stage of battery life. Two possible approaches to do so suggest themselves. First, an algorithm might somehow adapt the parameter values of the model during operation to match presently observed current–voltage behaviors; but, this must be done very carefully to avoid making the model unstable or physically nonmeaningful. Alternately, a set of models could be pre-computed at different feasible aging points and the model from this set that most closely predicts presently observed current–voltage dynamics could be selected from the set. This second approach guarantees stable and physically meaningful models since all models in the pre-computed set meet these criteria. We propose such an approach here. To do so, we first present a method for calculating a priori the changes to cell parameter values that will be produced by aging due to side reactions and/or material loss. These aged parameter values are utilized to produce reduced-order physics-based models at different stages of cell life. The reduced-order models are then used within a nonlinear interacting multiple-model Kalman filter to select the pre-computed model whose voltage predictions most resembles present measured voltage, so providing an estimate of the aged parameter values of a cell via the parameter values of this model. The selected model may then be used for state-of-charge estimation, state-of-power estimation, state-of-energy estimation, and other model-based battery-management tasks.
Cobalt sulfide-carbon composite powders were prepared by sulfidation of precursor powders obtained by spray drying. The precursor powders were composed of large particles with dimensions of several tens of micrometers and a hollow morphology with a thin-walled structure. The XRD pattern of the powders sulfidated at 200°C showed Co9S8 as the main phase and CoS as the minor phase. However, the XRD patterns of the powders sulfidated at 300 and 400°C showed CoS as the main phase and Co9S8, Co3S4, and CoS2 as the minor phases. The primary particle sizes of the powders sulfidated at 200, 300, and 400°C were 80, 190, and 230nm, respectively. Ultrafine cobalt sulfide crystals, a few nanometers in size, were uniformly distributed across the cobalt sulfide-carbon composite sheet. Dot-mapping images revealed that the carbon component was uniformly distributed throughout the composite powder. The optimum sulfidation temperature to obtain the composite powders with superior electrochemical properties was 300°C. The initial discharge and charge capacities of the composite powders sulfidated at 300°C at a current density of 1000mAg−1 were 1089 and 878mA h g−1, respectively. The discharge capacity of the composite powders sulfidated at 300°C became stable at around 790mA h g−1 for up to 70 cycles.
A biodegradable low-cost energy storage material has been obtained by using a self-assembly nanocomposite gelatin and graphene flakes. The blends with various ratio of graphene and gelatin have been prepared and characterized by Raman spectroscopy, cyclevoltammetry measurements, chronopotentiometry measurements and impedance spectroscopy. The ability of the biopolymer to bind the water–glycerol molecules and the graphene flakes leads to an improvement of the dielectric properties with a value of the surface capacitance of about 3 orders higher (10mFcm−2) than that measured for the device based on activated carbon. An electrical oxidation at the anode contact has been observed by applying to the device a higher bias voltage. The modified active material exhibits an enhancement of the cycle stability with a further increase of the surface capacitance (100mFcm−2) and of the respective specific capacitance up to a value of about 380Fg−1.
Poly(acrylonitrile-co-butyl acrylate) (P(AN-co-BuA))/poly(vinyl chloride) (PVC) blend-based gel polymer electrolyte (BGPE) was prepared for lithium-ion batteries. The P(AN-co-BuA)/PVC BGPE consists of an electrolyte-rich phase, which is mainly composed of P(AN-co-BuA) and liquid electrolyte, acting as a conducting channel and a PVC-rich phase that provides mechanical strength. The dual phase was just simply developed by the difference of miscibility properties in solvent, PC, between P(AN-co-BuA) and PVC. The mechanical strength of this new blend electrolyte was found to be much higher, with a fracture stress as high as 29MPa in dry membrane and 21MPa in gel state, than that of a previously reported P(AN-co-BuA)-based gel polymer electrolyte. The blended gel polymer electrolyte showed ionic conductivity of higher than 1.5×10−3 Scm−1 and electrochemical stability up to at least 4.8V. The results showed that the as-prepared gel polymer electrolytes were promising materials for lithium-ion batteries.
Dissolved polysulfides, formed during Li-S battery operation, freely migrate and react with both the Li anode and the sulfur cathode. These soluble polysulfides shuttle between the anode and cathode – the so-called shuttle effect – resulting in an infinite recharge process and poor Columbic efficiency. In this study, water present as an additive in the Li-S battery electrolyte is found to reduce the shuttle effect in Li-S batteries. Batteries where water content was below 50 ppm exhibited a substantial shuttle effect and low charge capacity. Alternatively, addition of 250 ppm water led to stable charge/discharge behavior with high Coulombic efficiency. XPS results show that H2O addition results in the formation of solid electrolyte interphase (SEI) film with more LiOH on Li anode which protects the Li anode from the polysulfides. Batteries cycled without water result in a SEI film with more Li2CO3 likely formed by direct contact between the Li metal and the solvent. Intermediate quantities of H2O in the electrolyte result in high cycle efficiency for the first few cycles which then rapidly decays. This suggests that H2O is consumed during battery cycling, likely by interaction with freshly exposed Li metal formed during Li deposition.
The intercalation of Li+ and ClO4 − ions in polypropylene–graphite composite electrodes in different single solvents and 1:1 binary solvent mixtures is studied by means of cyclic voltammetry and scanning electron microscopy. The intercalation/de-intercalation efficiency as a potential dual-intercalation battery electrode for cationic intercalation (positive electrode) is found to be generally lower than that for anionic intercalation in most of the solvents. 1:1 solvent mixtures do not enhance intercalation/de-intercalation efficiency significantly beyond the values found in a single solvent. The mixed-solvent system leads, however, to less co-solvent intercalation and graphite exfoliation, and hence better cycle-life as a potential battery electrode.
Being inherently safe and chemically compatible with the electrolyte, titanium oxide-based materials, including both Li-titanites and various TiO2 polymorphs, are considered alternatives to carbonaceous anodes in Li-ion batteries. Given the commercial success of the spinel lithium titanites, TiO2 polymorphs, in particular in nanostructured forms, have been fabricated and investigated for the applications. Nanostructuring leads to increased reaction areas, shortened Li+ diffusion and potentially enhanced solubility/capacity. Integration with an electron-conductive second phase into the TiO2-based nanostructures eases the electron transport, resulting in further improved lithium electrochemical activity and the overall electrochemical performance. This paper reviews structural characteristics and Li-electrochemical reactivity, along with synthetic approaches, of nanostructures and nano-composites based on lithium titanites and TiO2 polymorphs that include rutile, anatase, bronze and brookite.
A micro-porous polymer electrolyte based on PVA was obtained from PVA–PVC based polymer blend film by a novel preferential polymer dissolution technique. The ionic conductivity of micro-porous polymer electrolyte increases with increase in the removal of PVC content. Finally, the effect of variation of lithium salt concentration is studied for micro-porous polymer electrolyte of high ionic conductivity composition. The ionic conductivity of the micro-porous polymer electrolyte is measured in the temperature range of 301–351K. It is observed that a 2M LiClO4 solution of micro-porous polymer electrolyte has high ionic conductivity of 1.5055×10−3 Scm−1 at ambient temperature. Complexation and surface morphology of the micro-porous polymer electrolytes are studied by X-ray diffraction and SEM analysis. TG/DTA analysis informs that the micro-porous polymer electrolyte is thermally stable upto 277.9°C. Chronoamperommetry and linear sweep voltammetry studies were made to find out lithium transference number and stability of micro-porous polymer electrolyte membrane, respectively. Cyclic voltammetry study was performed for carbon/micro-porous polymer electrolyte/LiMn2O4 cell to reveal the compatibility and electrochemical stability between electrode materials.
Ruthenium/carbon composite materials are prepared by impregnating ruthenium(III) acetylacetonate into a mesoporous carbon (average pore diameter=12mn, pore volume=3.6cm3 g−1) and then heat treatment at 320°C for 2h under an argon atmosphere. The metallic ruthenium nanoparticles are converted to pseudo-capacitive hydrous ruthenium oxide by electrochemical oxidation at 0.75V (versus SCE) for 2h in 2.0M H2SO4. The specific capacitance of the composite electrodes, which is the sum of the double-layer capacitance of mesoporous carbon and the pseudo-capacitance of hydrous ruthenium oxide, reaches 243Fg−1 with heavy loading. As the loading is increased, however, the degree of ruthenium utilization for a pseudo-capacitor becomes poorer, presumably due to a limited conversion to the hydrous oxide form. The rate capability of composite electrodes also decreases with increase in ruthenium loading, due to an increase in both the equivalent series resistance (ESR) and the overall capacitance value. The ESR enlargement is caused mainly an increase in the electrolyte resistance within pores which, in turn, results from a pore narrowing with ruthenium loading Hindered ionic motion in narrowed pores can explain this feature. An increase in the RC time constant with ruthenium loading is further verified by ac impedance measurements.
The 2016–2018National Invasive Species Council (NISC) Management Plan and Executive Order 13751 call for US federal agencies to foster technology development and application to address invasive species and their impacts. This paper complements and draws on an Innovation Summit, review of advanced biotechnologies applicable to invasive species management, and a survey of federal agencies that respond to these high-level directives. We provide an assessment of federal government capacities for the early detection of and rapid response to invasive species (EDRR) through advances in technology application; examples of emerging technologies for the detection, identification, reporting, and response to invasive species; and guidance for fostering further advancements in applicable technologies. Throughout the paper, we provide examples of how federal agencies are applying technologies to improve programmatic effectiveness and cost-efficiencies. We also highlight the outstanding technology-related needs identified by federal agencies to overcome barriers to enacting EDRR. Examples include improvements in research facility infrastructure, data mobilization across a wide range of invasive species parameters (from genetic to landscape scales), promotion of and support for filling key gaps in technological capacity (e.g., portable, field-ready devices with automated capacities), and greater investments in technology prizes and challenge competitions.