batterydata/paper-abstracts huggingface dataset:
We present a mobility resilient deterministic broadcast algorithm with worst-case time complexity of O ( n log n ) for ad hoc networks where the nodes possess collision detection capabilities; n is the total number of nodes in the network. The algorithm is based on a breadth-first traversal of the network and allows multiple simultaneous transmissions by the nodes. The idea of this broadcast algorithm is then extended to develop a mobility resilient deterministic gossiping algorithm having O ( D n log n ) worst-case run time ( D is the diameter of the network graph), which is an improvement over the existing algorithms. Simulation results show that on an average, the time for completing the broadcast or gossiping is significantly lower than the theoretical worst-case time requirement.
Most non-aqueous lithium-air batteries reported in the literature are limited to operating with pure oxygen. To practically operate the battery in ambient air, understanding how the battery’s performance varies with humidity of moist air is essential. Here we study the effects of moist air on the cycling performance through operating a non-aqueous lithium-air battery with a stable anode and a nano-structured RuO2/NiO cathode at various relative humidities. Results show that in the dry air, the discharge and charge terminal voltages are around 2.51 and 4.12V, respectively, but change to 2.79 and 3.87V when the relative humidity reaches 84%. The energy efficiencies corresponding to the dry air and the relative humidity of 84% are 66.2% and 73.8%, respectively. The improved performance is found to be mainly due to the increased fraction of LiOH among the discharge products at high relative humidities. The discharge voltage for the formation of LiOH is higher than that for the formation of Li2O2, while the charge voltage for the decomposition of LiOH is lower than that for the decomposition of Li2O2. The results suggest that to enable a non-aqueous lithium-air battery to operate in moist air, in addition to protecting the lithium anode from water, designing a cathode with electrocatalytic activities for the decomposition of both Li2O2 and LiOH is required.
This work addresses the issue of radiation chemical synthesis of MnO2 nanoparticles and also illustrates the ease of formation of nanorods and sheets by adroit manipulation of experimental conditions. The radiation chemical yield (G-value) for reduction of Mn (VII) by the hydrated electron was found to be 0.27μmolJ−1 and 0.17μmolJ−1 respectively, when tert. butanol and isopropanol were used as scavengers in nitrogen-saturated solutions. The colloids formed upon irradiation of air-saturated solution and N2-purged solution with tert. butanol as scavenger were found to be most stable. Irradiation of air-saturated solution containing 4×10−4 MKMnO4 at a dose of 1692Gy resulted in the formation of nanorods of the dimension 100–150nm and nanospheres in the range 10–20nm. Irradiation of N2-purged solution containing tert. butanol as scavenger for OH-produced reticulated structure of nanorods with length varying from 50 to 100nm at a dose of 1692Gy. Elemental analysis was performed using scanning electron microscope on MnO2 formed by reduction and oxidation and the purity was found to be 98% of elemental Mn content.
Functional materials, especially those that largely differ from known materials, are not easily discoverable because both human experts and supervised machine learning need prior knowledge and datasets. An autonomous system can evaluate various properties a priori, and thereby explore unknown extrapolation spaces in high-throughput simulations. However, high-throughput evaluations of molecular dynamics simulations are unrealistically demanding. Here, we show an autonomous search system for organic molecules implemented by a reinforcement learning algorithm, and apply it to molecular dynamics simulations of viscosity. The evaluation is dramatically accelerated (by three orders of magnitude) using a femto-second stress-tensor correlation, which underlies the glass-transition model. We experimentally examine one of 55,000 lubricant oil molecules found by the system. This study indicates that merging simulations and physical models can open a path for simulation-driven approaches to materials informatics.
A combined method for the simultaneous measurement of the clamping pressure distribution and endplates deformation in polymer electrolyte fuel cells (PEFC) is presented. The proposed approach, which allows overcoming some important limitations associated with the use of conventional pre-scaled pressure films, is used to investigate the correlation between the actual pressure distribution on the membrane electrode assembly (MEA), the endplate out-of-plane deformation and the applied clamping torque, for two single fuel cells assembled with either copper or aluminium/copper endplates. Results proved that, in point-load design PEFCs, both pressure magnitude and distribution are affected by endplates deformation and thickness mismatching between the sealing gasket and the MEA. Moreover, while the average pressure on the MEA displays a slight increase (+25%) as the clamping torque is raised from 5 to 10Nm, it increases monotonically on the sealing gasket, with local peaks that exceed the saturation level of the sensor array (20.7MPa). A dimensionless uniformity index has been introduced to assess the uniformity of the pressure distribution, allowing an easy comparison of different fuel cell assembly configurations. The proposed methodology might assist the design of next-generation fuel cells or could be used as a powerful validation tool for detailed finite element models. It can also be applied to study other kind of fuel cells and batteries as well.
Direct estimation of battery performance is a major challenge as ageing process is a complex phenomenon not directly measurable. In this work a new methodology is provided to estimate global battery performances under real-life electric vehicle use. Such performances are estimated through battery signals patterns extraction. These signals patterns are used to identify physical degradation behavior of batteries. The analysis framework is composed of patterns extraction, clustering algorithms, summarizing data representation in the feature space of cluster distances and classification algorithms. This methodology is then applied on datasets, acquired from batteries used on electric vehicles, without controlled environmental conditions. The classification algorithm accuracy is studied on the obtained real data. The results suggest that battery signals patterns analysis provides an innovative technique for online estimation of the battery performance level. A detection of dysfunctions caused by ageing is also made, only based on battery signals pattern extracted during real vehicle accelerations.
The reversibility of zinc anode in alkaline medium was enhanced by electrostatic deposition of a conducting polymer (polypyrrole). Electropolymerization of pyrrole onto zinc in aqueous medium using an organic acid as dopant is feasible and preferred as zinc is less corrosive in this medium. The structure of the polymer film was analyzed by FT-IR spectroscopy and scanning electron microscopy. The effect of the polypyrrole deposit on the zinc electrode was studied by cyclic voltammetry and charge–discharge cycling.
For the first time, the effect of the nanowires diameter in terms of size and distribution on electrochemical properties of SiNWs grown by VLS was investigated. The diameter size was tuned by using three different gold catalyst film thicknesses. The crucial influence of this parameter is evidenced through comparison of the charge–discharge behavior and a study of the rate capability for the three samples. The rechargeable capacity as well as the rate capability is shown to be the best when the smallest diameters (<65nm) are used compared to larger one (<210nm and <490nm). High capacity values of 3500mAhg−1 are obtained for the smallest diameters at C/5 rate but still 2500, 1500 and 500mAhg−1 are recovered at C, 2.5C and 5C. An excellent cycle life over 50 cycles is achieved at 1.3C with a capacity of 2500mAhg−1. This shows that by tailoring the diameter size and distribution, SiNWs can provide high power density anodes in lithium ion batteries.
Despite tremendous progress in the development of LiS batteries, their performance at the full-cell level is not as competitive as state-of-the-art Li-ion batteries. Here the authors report a full-cell architecture making use of a hybrid intercalation-conversion cathode, enabling both high volumetric and gravimetric energy densities.
Electrical energy storage could play an important role in decarbonizing the electricity sector by offering a new, carbon-free source of operational flexibility, improving the utilization of generation assets, and facilitating the integration of variable renewable energy sources. Yet, the future cost of energy storage technologies is uncertain, and the value that they can bring to the system depends on multiple factors. Moreover, the marginal value of storage diminishes as more energy storage capacity is deployed. To explore the potential value of energy storage in deep decarbonization of the electricity sector, we assess the impact of increasing levels of energy storage capacity on both power system operations and investments in generation capacity using a generation capacity expansion model with detailed unit commitment constraints. In a case study of a system with load and renewable resource characteristics from the U.S. state of Texas, we find that energy storage delivers value by increasing the cost-effective penetration of renewable energy, reducing total investments in nuclear power and gas-fired peaking units, and improving the utilization of all installed capacity. However, we find that the value delivered by energy storage with a 2-hour storage capacity only exceeds current technology costs under strict emissions limits, implying that substantial cost reductions in battery storage are needed to justify large-scale deployment. In contrast, storage resources with a 10-hour storage capacity deliver value consistent with the current cost of pumped hydroelectric storage. In general, while energy storage appears essential to enable decarbonization strategies dependent on very high shares of wind and solar energy, storage is not a requisite if a diverse mix of flexible, low-carbon power sources is employed, including flexible nuclear power.
Mechanisms for ion transport, diffusion and intercalation/deintercalation processes in batteries during charging and discharging are described by governing equations that consist of partial differential equations and nonlinear functions. Solving these equations numerically is computational intensive, particularly when the number of cells connected in series and parallel for high power or energy increases, whereas tolerance of errors should be kept under specified limits. Reduction of the computational time is required not only for enabling simulation of the behavior of packs, but also for development of a model capable of running in real time environments, so that new advanced estimation methods for state of charge (SOC) and state of health (SOH) can be developed. In our previous research work, a reduced order model (ROM) was developed using different techniques including polymoninal approximation and residue grouping, which represents the physical behaviors of a battery. However, computational time has not been optimized. In this paper, methods to reduce the computational time are analyzed and employed to reduce the computational time while considering the accuracy. Apart from retaining the residue grouping method for the ion concentration in electrolyte and linearization of the Butler–Volmer equation, the Padé approximation is introduced to simplify the calculation of ion concentration in electrode particles governed by the Fick’s second law. Meanwhile, discretized governing equations for potentials in electrodes and electrolytes are reduced by employing proper orthogonal decomposition (POD). In addition, expressions of the equilibrium potentials for anodes and cathodes are fitted to different order polynomials. The reduced equations are coupled to construct a single cell model for a large format lithium polymer battery that is validated against experimental data. The results show that the ROM proposed can reduce the computational time at least to one-tenth of the models developed previously, while overall accuracies can be maintained.
The cycling efficiencies and cycling performance of a lithium metal anode in a vinylene carbonate (VC)-containing electrolyte were evaluated using Li/Ni and LiCoO2/Li coin type cells. The cycling efficiencies of deposited lithium on a nickel substrate in an EC + DMC (1:1) electrolyte containing LiPF6, LiBF4, LiN(SO2CF3)2 (LiTFSI), or LiN(SO2C2F5) (LiBETI) at 25 and 50°C were improved by presence of VC. However, the lithium cycling efficiencies at low temperature (0°C) decreased by adding VC to the EC+DMC (1:1) electrolyte. The deposited lithium at low temperature exhibited a dendritic morphology and a thicker surface film. The lithium ion conductivity of the VC derived surface film was lower than that of the VC-free surface film at low temperature. Therefore, we concluded that the cycling efficiency decreased with decreasing temperature. On the other hand, the cell containing VC additive has excellent performance at elevated temperature. The deposited lithium at 50°C in the VC-containing electrolyte exhibited a particulate morphology and formed a thinner surface film. The VC derived surface film, which consists of polymeric species, suppressed the deleterious reaction between the deposited lithium and the electrolyte.
Hybrid power systems based on renewable energy sources, especially photovoltaic and wind energy are an effective option to solve the power-supply problem for remote and isolated areas far from the grids. This paper presents a study and design of a complete hybrid system for providing the electrical loads in a family house in Palestine according to their energy requirements. A computer program is developed to achieve this and to determine the specifications of the whole system components. It uses the data of wind and solar radiation measurements of the selected rural zone and all the required information about the electrical loads. Also, the hybrid systems minimizing, simultaneously, the total cost throughout the useful life of the installation, pollutant emissions (CO2) and dump load are taken into consideration. It is found that providing electricity to a family house in a rural zone using hybrid systems is very beneficial and competitive with the other types of conventional energy sources, especially considering the decreasing prices of these systems and their increasing efficiencies and reliability. They have also the advantage of maintaining a clean environment.
Electrochemical performance of a graphite electrode for lithium ion batteries are easily improved by sodium ion dissolved in an electrolyte solution as reported recently by our group. On the contrary, when potassium ions were added by dissolving 0.2moldm−3 KPF6 into a 1moldm−3 LiPF6 ethylene carbonate–diethyl carbonate (1:1, v/v) electrolyte solution prior to charge–discharge cycle, an electrochemical performance of a graphite electrode was deteriorated compared to that tested in an additive free electrolyte; larger irreversible capacity at the first cycle and worse retention of discharge capacities on successive cyclings. During the first charge in a potassium additive system, ex situ XRD observation of graphite electrodes revealed that lithium intercalation hardly proceeded in the lower potential region less than 0.1V versus Li though lithium ions were intercalated at >0.1V. Electroreduction of potassium ions on the electrode occurred instead of lithium intercalation into graphite in the lower potential region. Furthermore, the electrode surface morphology observed by electron microscopes after charge–discharge tests got less uniform in the potassium added electrolyte.
The antinociceptive response of mice to the amino acid l-arginine (l-ARG) has been attributed to either an opioid mechanism or a non-opioid but nitric oxide (NO)-dependent mechanism. Earlier it was reported that the mechanism of nitrous oxide-induced antinociception involved opioid components and was also dependent on brain NO. This study was designed to determine whether the antinociceptive effects of l-ARG and the NO donor 3-morpholinosydnoimine (SIN-1) might be mediated by brain mechanisms similar to those that are responsible for nitrous oxide (N2O) antinociception. l-ARG and SIN-1 were administered to mice intracerebroventricularly (i.c.v.), and antinociception was assessed using the acetic acid abdominal constriction test. Both l-ARG and SIN-1 caused dose-related antinociceptive effects that were blocked by naloxone and norbinaltorphimine. The antinociceptive effects of both SIN-1 and l-ARG were also blocked to a greater extent by i.c.v. administration of a rabbit antiserum against rat dynorphin 1–13 than an antiserum against methionine-enkephalin, suggesting that the SIN-1 and l-ARG effects may be related to stimulated release of dynorphin. The antinociceptive effect of l-ARG was antagonized by an inhibitor of neuoronal NO synthase enzyme, indicating that l-ARG had to be converted to NO for its antinociceptive action. These findings indicate that the mechanisms of antinociceptive action of l-ARG and SIN-1 are both mediated by dynorphin and dependent on NO.
In recent work [J. Morales, J. Santos-Peña, Electrochem. Commun. 9 (2007) 2116], we prepared nanosized α-LiFeO2 with increased electrochemical activity in lithium cells relative to various lithium ferrite polymorphs. In this work, we studied the previous electrodes in different charge states in order to obtain a more accurate picture of the phenomena occurring during cycling. Ex situ X-ray photoelectron spectroscopy (XPS) measurements confirmed the oxidation/reduction of iron atoms during the charge/discharge process. The electrochemical impedance spectroscopy results suggested that the electrolyte is not oxidised during the first charge, but rather than a solid electrolyte interface is formed after one cycle. Also, thermal tests revealed that Fe(IV) present in the electrodes reacted with the electrolyte to form oxidised carbon species. Finally, α-LiFeO2 was tested as a positive electrode material in a lithium battery under different regimes. Stabilised capacities up to 150mAhg−1 were obtained under a C/4 regime. This lithium ferrite is therefore an attractive alternative to LiCoO2.
This paper presents the results of an experimental study of a PV/diesel hybrid system without storage. Experimental results show that the sizing of a PV/diesel hybrid system by taking into account the solar radiation and the load/demand profile of a typical area may lead the diesel generator to operate near its optimal point (70–80% of its nominal power). The present paper shows that for a reliability of a PV/diesel hybrid system, the rated power of the diesel generator should be equal to the peak load. By the way, it has been verified through this study that the functioning of a PV/diesel hybrid system is efficient for higher load and higher solar radiation.
Electric vehicles enable clean and efficient transportation, however concerns about range anxiety and battery degradation hinder EV adoption. The common definition for battery end-of-life is when 70–80% of original energy capacity remains, however little analysis is available to support this retirement threshold. By applying detailed physics-based models of EVs with data on how drivers use their cars, we show that EV batteries continue to meet daily travel needs of drivers well beyond capacity fade of 80% remaining energy storage capacity. Further, we show that EV batteries with substantial energy capacity fade continue to provide sufficient buffer charge for unexpected trips with long distances. We show that enabling charging in more locations, even if only with 120 V wall outlets, prolongs useful life of EV batteries. Battery power fade is also examined and we show EVs meet performance requirements even down to 30% remaining power capacity. Our findings show that defining battery retirement at 70–80% remaining capacity is inaccurate. Battery retirement should instead be governed by when batteries no longer satisfy daily travel needs of a driver. Using this alternative retirement metric, we present results on the fraction of EV batteries that may be retired with different levels of energy capacity fade.
Layered lithium-rich Oxides (LLROs) suffer from serious capacity fading during the cycling especially when the size is in sub-micron or nanoscale. Here we report the polyacrylonitrile (PAN) as a binder to maintain the capacity of LLROs sized ∼200 nm, the combined PAN with polyvinylidene fluoride (PVDF) achieve excellent cycle and rate performance as the composite binder taking advantages from both PAN and PVDF. The capacity retention of PAN-PVDF electrode after 40 cycles is 89.6%, comparing to the 77.5% of PVDF electrode and 85.1% of PAN electrode. The SEM images pronouncedly illustrates that PAN-PVDF as composite binder holds the active material on the laminates firmly, resulting few cracks and voids. The electrochemical impedance spectra indicate that averting those voids and cracks lead to lower resistance. The composite binder has played a significant role in improving the cycling and rate performance of LLROs.
In mobile devices there exist several in-built sensor units and sources which provide data for context reasoning. More context sources can be attached via wireless network connections. Usually, the mobile devices and the context sources are battery powered and their computational and space resources are limited. This sets special requirements for the context recognition algorithms. In this paper, several classification and automatic feature selection algorithms are compared in the context recognition domain. The main goal of this study is to investigate how much advantage can be achieved by using sophisticated and complex classification methods compared with a simple method that can easily be implemented in mobile devices. The main result is that even a simple linear classification algorithm can achieve a reasonably good accuracy if the features calculated from raw data are selected in a suitable way. Usually context recognition algorithms are fitted to a particular problem instance in an off-line manner and modifying methods for on-line learning is difficult or impossible. An on-line version of the Minimum-distance classifier is presented in this paper and it is justified that it leads to considerably higher classification accuracies compared with the static off-line version of the algorithm. Moreover, we report superior performance for the Minimum-distance classifier compared to other classifiers from the view point of computational load and power consumption of a smart phone.