batterydata/paper-abstracts huggingface dataset:
Rational electrode architectural design, favorable electrode composition, and versatile synthesis approach play a significant role in developing advanced electrodes for high-performance supercapacitor. In this work, we report a facile approach for fabricating 1D hierarchical CuO@Co x Ni 1−x (OH)2 nanowire arrays grown on 3D highly conductive copper foam. The optimized CuO@Co0.2Ni0.8(OH)2 electrode delivers an ultrahigh specific capacity of 374.7 mAh g−1 at 2 A g−1 with exceptional rate capability (301.7 mAh g−1 at 50 A g−1) and remarkable cycling stability (95.9% after 10 000 cycles at 50 A g−1). A flexible asymmetric solid-state supercapacitor (ASC) is fabricated using the optimized CuO@Co0.2Ni0.8(OH)2 as the positive electrode, activated carbon-coated nickel foam as the negative electrode, and polyvinyl alcohol/KOH gel as electrolyte. The flexible ASC operating with a potential window of 0–1.6 V delivers an energy density of 46.5 Wh kg−1 with a power density of 526.9 W kg−1. The ASC also exhibits excellent cycling stability with a capacity retention of 84.3% after 10 000 cycles at a current density of 7 A g−1.
A new method for the simultaneous measurement of the effective ionic conductivity and effective electronic conductivity in a porous sheet consisting of an electronic conductor and an ionic conductor (electrolyte) is proposed. In this method, two potentiostats and a voltage source are used, and these instruments are connected to the sample via two terminals made of the electronic conductor and two terminals made of the ionic conductor. The underlying principle of this technique does not include any assumption about charge-transfer resistance at the ionic conductor/electronic conductor interface, since the measurement is designed to let the potential difference at the interface be the OCP value at each point throughout the sample. The validity of this method was confirmed by measuring a pseudo-catalyst layer for a proton-exchange membrane fuel cell (PEMFC). The results revealed that the effective ionic and electronic conductivity depends on the relative humidity.
Electrochemical double layer capacitors (EDLCs) are inherently high power devices when compared to rechargeable batteries. While capacitance and energy storage ability are mainly increased by optimizing the electrode active material or the electrolyte, the power capability could be improved by including conductive additives in the electrode formulations. This publication deals with the use of four different carbon additives – two carbon blacks and two graphites – in standard activated carbon based EDLC electrodes. The investigations include: (i) physical characterization of carbon powder mixtures such as surface area, press density, and electrical resistivity measurements, and (ii), electrochemical characterization via impedance spectroscopy and cyclic voltammetry of full cells made with electrodes containing 5 wt.% of carbon additive and compared to cells made with pure activated carbon electrodes in organic electrolyte. Improved cell performance was observed in both impedance and cyclic voltammetry responses. The results are discussed considering the main characteristics of the different carbon additives, and important considerations about electrode structure and processability are drawn.
Certain grinding operations need a specially shaped wheel for regular surface texture (RST) generation. In such cases, wheel nominal active surface is reproduced on the ground surface in a special way. The simple version of the method consists in grinding with the wheel having helical grooves which are deeper than the grinding depth. Pattern regularity depends in longer time on wheel wear. The grinding force is thus one of the most important process indicators. A simulation model of grinding process, assuming random arrangement of abrasive grains was developed and is presented in this paper. The model was verified by grinding force measurements. These measurements showed specific features that were different from those characteristic of conventional grinding. Explanations of the untypical effects observed at force–time series signals for the three basic types of surface patterns are provided.
The rechargeable Li-air battery has a key role to play for future renewable energy and electric vehicle industries due to its high energy density. However, it suffers from cycling fading and low rate capability, mainly caused by the problem of cathode. Here we create a nanoporous three-dimensional gas diffusion electrode to replace a conventional composite electrode, prolonging battery cycle life over 200 cycles with higher rate capabilities and high capacities. Electrochemical and spectroscopic characterisations indicate the mechanism for the improvement.
Electrochromic (EC) devices are capable of reversibly changing optical properties upon charge injection and extraction driven by an externally applied voltage. A nanogenerator (NG) is a device that converts mechanical energy into electricity. This paper demonstrates a self-powered EC device driven by an NG. An average visible optical modulation (ΔTvis) as large as 15.3% was obtained, with electrochromic response time (ERT) and coloration efficiency (CE) of 10 seconds and 58.7 cm2 C−1, respectively. Such a performance is comparable to an EC when powered by a hardwired DC power. This study indicates that the self-powered electrochromic system can be a candidate for monochrome displays or electronic billboards.
Nano-size (≤100nm) TiP2O7 is prepared by the urea assisted combustion synthesis, at 450 and 900°C. The compound is characterized by powder X-ray diffraction, Rietveld refinement, high resolution transmission electron microscopy and surface area methods. Lithium cycling properties by way of galvanostatic cycling and cyclic voltammetry (CV) showed a reversible and stable capacity of 60 (±3)mAhg−1 (0.5mole of Li) up to 100 cycles, when cycled at 15mAg−1 between 2–3.4V vs. Li. Non-aqueous hybrid supercapacitor, TiP2O7 (as anode) and activated carbon (AC) (as cathode) has been studied by galvanostatic cycling and CV in the range, 0–3 V at 31mAg−1 and exhibited a specific discharge capacitance of 29 (±1)Fg−1stable in the range, 100–500 cycles. The Ragone plot shows a deliverable maximum of 13Whkg−1 and 371Wkg−1 energy and power density, respectively.
ABSTRACT This paper describes a method for the preparation of composite cathodes for lithium ion-batteries by using poly vinyl acetate (PVAc) as a binder. PVAc is a non-fluorinated water dispersible polymer commonly used in a large number of industrial applications. The main advantages for using of this polymer are related to its low cost and negligible toxicity. Furthermore, since the PVAc is water processable, its use allows to replace the organic solvent, employed to dissolve the fluorinated polymer normally used as a binder in lithium battery technology, with water. In such a way it is possible to decrease the hazardousness of the preparation process as well as the production costs of the electrodes. In the paper the preparation, characterization and electrochemical performance of a LiFePO4 electrode based on PVAc as the binder is described. Furthermore, to assess the effect of the PVAc binder on the electrode properties, its performance is compared to that of a conventional electrode employing PVdF-HFP as a binder.
In this article, we will focus on the development of electrical energy storage systems, their working principle, and their fascinating history. Since the early days of electricity, people have tried various methods to store electricity. One of the earliest devices was the Leyden jar which is a simple electrostatic capacitor that could store less than a micro Joule of energy. The battery has been the most popular in storing electricity as it has higher energy density. In this article, we will describe and compare the working of various kinds of batteries and capacitors. We will review the recent technological breakthrough in electrical energy storage devices.
Lithium-ion batteries are expected to serve as a key technology for large-scale energy storage systems (ESSs), which will help satisfy recent increasing demands for renewable energy utilization. Besides their promising electrochemical performance, the low self-discharge rate (<5% of the stored capacity over 1 month) of lithium-ion batteries is one of their most significant advantages for ESSs. Herein, contrary to conventional belief, we report that the self-discharge of LIBs can be abnormally accelerated when the battery has been exposed even to a routine short-term thermal exposure. We demonstrate that this thermal ‘history’ in addition to the temperature itself is memorized in the battery and accelerates the self-discharge rate. The series of characterizations performed in our work reveal that the electrolyte salt acts as a strong oxidizing agent by vigorously damaging the surface of the cathode, producing an internal ‘parasitic’ lithium source that continuously supplies lithium for the self-discharge. Although it is widely known that battery operation at elevated temperature generally induces faster degradation of capacity over multiple cycles, the key finding here is that not only the operation temperature but also the ‘thermal history’ of the battery should be carefully considered because this history remains and continues to affect the self-discharge rate afterwards. The self-discharge of LIBs has remained largely neglected; however, our findings suggest that close attention must be paid to the self-discharge of LIBs applied to large-scale ESSs, which, unlike mobile electronic devices, will be exposed to various outdoor temperature conditions.
A portable system for power generation based on hydrogen and a single proton exchange membrane fuel cell (PEMFC) has been built and operated. The fuel cell is fed in the anode with hydrogen stored in a metal hydrides cartridge, and in the cathode with oxygen from quiescent ambient air (‘air breathing’). The control electronics of the system performs DC–DC conversion from the low voltage (0.5–0.8V) and high current output (200–300mAcm−2) of the single fuel cell, up to 3.3V to power an electronic application. System components assist fuel cell operation, including an electronic valve for anode purging, a fan in front of the open cathode, two supercapacitors for auxiliary power requirements, four LED lights, and a display screen. The influence of the system components on fuel cell behaviour is analyzed. The cathode fan and anodic purging help excess water removal from the electrodes leading to steadier cell response at the expense of extra power consumption. The power system is able to provide above 1W DC electricity to an external application during 20h using 1g of H2. An application consisting of a propeller able to display a luminous message is chosen to test system. It is shown that one single air breathing PEM fuel cell powered with hydrogen may provide high energy density and autonomy for portable applications.
Information and communication technology (ICT), characterized by continual innovation and rapid technological change, is having a tremendous impact on society. Research and development in ICT are being conducted throughout the technology sector, and fundamental research is being carried out in many university departments of electronics, computer science, and engineering. This paper deals with frontiers of research and trends in selected areas of ICT, including computer hardware, microelectronics, and semiconductor devices and materials—areas that are leading the innovations in ICT. It briefly describes emerging technological developments, and concludes with advances in software engineering.
Nowadays, renewable energy plays a vital role in the sustainable development of a society. In China, renewable energy power has developed rapidly since the implementation of Renewable Energy Act. Through a series of specific incentive measures, especially subsidy policies, China׳s renewable energy power has made great achievements both in technology and application. Based on the state-of-the-art of renewable energy power, this paper comprehensively analyzed the costs and benefits of renewable energy power subsidy in China. The analysis results show the cost of renewable energy power subsidy was 0.248CNY/kWh between 2006 and April 2011, which was distributed among different renewable energy power types (including wind power, biomass power, and solar PV power) or categories (including electricity price, accessing-grid projects, and public independent renewable energy power system). On the other hand, the renewable energy power subsidy also brings benefits to different aspects of the society. Specifically, the environmental benefit amounted to 17.88 billion CNY, and the benefits of guaranteeing energy security, advancing technology innovation and promoting economic development were also noteworthy.
In this paper, we present an integrated device in which an UV detector and a supercapacitor are built on the same vertical-aligned silicon nanowire (SiNW) array electrode. It is found that the embedded supercapacitor is of an impressive capacitance density of 13.6Fcm−3 and able to power the detector for more than 10h with a single charge in less than 100s. The fast and stable UV light responsivity of the detector has been demonstrated during the whole working period. This low cost high performance device has proved a type of promising applications in which a sensor is seamlessly integrated with a power source for its functions.
Li-ion battery performance degrades with aging and usage, and the degradation highly depends on how the cell is operated. As such, models used for system design and optimization should ideally capture the impact of those effects, and battery management system should take degradation into consideration and control cell operation carefully. Physics-based electrochemical models have shown the capability of predicting cell performance and degradation, but are computationally time consuming, often precluding its use in control-oriented design/optimization. Based on the constitutive laws which are widely adopted in the electrochemical models, a control-oriented reduced-order degradation model for a commercial LiNiMnCoO2/graphite cell is derived to improve computational efficiency without sacrificing model fidelity. Three primary degradation mechanisms that occur in a typical Li-ion cell are captured: 1) Solid Electrolyte Interface (SEI) layer growth, 2) SEI layer fracture and re-healing, and 3) Active Material loss. The extensive validation against a wide range of experimental data illustrates the ability of the model to accurately predict the capacity loss.
The objective of this paper is to address the issue of the production cost of second generation biofuels via the thermo-chemical route. The last decade has seen a large number of technical–economic studies of second generation biofuels. As there is a large variation in the announced production costs of second generation biofuels in the literature, this paper clarifies some of the reasons for these variations and helps obtain a clearer picture. This paper presents simulations for two pathways and comparative production pathways previously published in the literature in the years between 2000 and 2011. It also includes a critical comparison and analysis of previously published studies. This paper does not include studies where the production is boosted with a hydrogen injection to improve the carbon yield. The only optimisation included is the recycle of tail gas. It is shown that the fuel can be produced on a large scale at prices of around 1.0–1.4 € per l. Large uncertainties remain however with regard to the precision of the economic predictions, the technology choices, the investment cost estimation and even the financial models to calculate the production costs. The benefit of a tail gas recycle is also examined; its benefit largely depends on the selling price of the produced electricity.
Ametek Edax has introduced the OIM Matrix software package, which brings dynamic diffraction-based electron backscatter diffraction (EBSD) pattern simulations and dictionary indexing capabilities to the EBSD market. The OIM Matrix package allows users to simulate EBSD patterns based on the physics of dynamical diffraction of electrons. This approach more accurately describes the behavior of the electron interactions within a sample and produces more realistic pattern simulations compared with traditional kinematic-diffraction-based approaches. These simulated patterns can then be more easily and accurately compared with experimentally collected EBSD patterns.
Undoped SnO2 thin films have been deposited on amorphous glass substrates with different precursor solution volume (10, 15, 20 and 25 ml) using simple and cost-effective nebulized spray pyrolysis technique. The influence of precursor solution on structural, optical, photoluminescence and electrical properties had been studied. The X-ray diffraction spectra prove the polycrystalline nature of SnO2 with tetragonal structure. All the films show a preferred growth orientation along (110) diffraction plane. The average transmittance of SnO2 thin films varied between 82 and 75% in the visible as well as IR region. The band gap energy decreases from 3.74 to 3.64 eV corresponding to direct transitions with the precursor solution volume had increased from 10 to 20 ml and then increased as 3.72 eV for 25 ml. SEM pictures demonstrated polyhedrons like grains. EDX confirmed the existence of Sn and O elements in all the prepared SnO2 thin films. Photoluminescence spectra at room temperature revealed that the four emission bands in all the samples such as sharp dominant peak at 361 nm with shoulder peak at 377 nm (UV region), a broad and low intensity peak at 492 nm (blue region) and 519 nm (green region). The electrical parameters were examined by Hall effect measurements, which demonstrated that the film prepared at 20 ml precursor solution volume possess minimum resistivity 2.76 × 10−3 Ω-cm with activation energy 0.10 eV and maximum figure of merit 1.54 × 10−2 (Ω/sq)−1.
Three-dimensional compressible flow simulations were conducted to develop a Hyperloop pod. The novelty is the usage of Gamma transition model, in which the transition from laminar to turbulent flow can be predicted. First, a mesh dependency study was undertaken, showing second-order convergence with respect to the mesh refinement. Second, an aerodynamic analysis for two designs, short and optimized, was conducted with the traveling speed 125 m/s at the system pressure 0.15 bar. The concept of the short model was to delay the transition to decrease the frictional drag; meanwhile that of the optimized design was to minimize the pressure drag by decreasing the frontal area and introduce the transition more toward the front of the pod. The computed results show that the transition of the short model occurred more on the rear side due to the pod shape, which resulted in 8% smaller frictional drag coefficient than that for the optimized model. The pressure drag for the optimized design was 24% smaller than that for the short design, half of which is due to the decrease in the frontal area, and the other half is due to the smoothed rear-end shape. The total drag for the optimized model was 14% smaller than that for the short model. Finally, the influence of the system pressure was investigated. As the system pressure and the Reynolds number increase, the frictional drag coefficient increases, and the transition point moves toward the front, which are the typical phenomena observed in the transition regime.
This paper describes a facile, single-step hydrothermal method to prepare ruthenium sulfide/thermally reduced graphene oxide (RuS2/TRGO) nanocomposites. In this synthesis procedure, aqueous solutions of RuCl3, l-cysteine, and graphene oxide are employed as the metal, sulfur, and graphene sources, respectively. The chemical structures and morphologies of the nanocomposites are characterized by X-ray diffraction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. Cyclic voltammetry, galvanostatic charge-discharge cycling, and electrochemical impedance spectroscopy are used to examine their electrochemical performances. The RuS2 nanoparticles (∼10 nm) uniformly disperse on the surfaces of the TRGO layers to form the RuS2/TRGO composite, which adequately inhibits aggregation of the RuS2 to fully exploit its impressive electrochemical activity and capacitance as a pseudocapacitive electrode material. The combination of the TRGO interconnected conductive networks and uniformly anchored RuS2 generates a specific capacitance of 193 F g−1 at a 5 mV s−1 scan rate, 150 F g−1 at a 0.5 A g−1 current density, good rate capability (57.3% retention at 6.25 A g−1), and reasonable cycle stability (90% retention of capacitance over 2000 cycles at a current density of 0.75 A g−1). Further, the RuS2/TRGO-30 composite electrode achieves energy densities of 20.84 and 6.11 Wh kg−1 at power densities of 250 and 3666.7 W kg−1, respectively. The RuS2/TRGO composites are promising for high-level energy storage applications because of their superior electrochemical activities.
Big data have become an important asset due to its immense power hidden in analytics. Every organization is inundated with colossal amount of data generated with high speed, requiring high-performance resources for storage and processing, special skills and technologies to get value out of it. Sources of big data may be either internal or external to organization, and big data may reside in structured, semi-structured or unstructured form. Artificial intelligence, Internet of Things, and social media are contributing to the growth of big data. Analytics is the use of statistics, maths, and machine learning to derive meaningful insights from data to make timely decisions and enable data-driven organization of the future. This paper sheds light upon big data, taxonomy of data, and hierarchical journey of data from its original form to the high level understanding in terms of wisdom. The paper also focuses on key characteristics of big data and challenges of handling big data. In addition, big data storage systems have also been briefly covered to get the idea on how storage systems help to accommodate the requirements of big data. This paper scrupulously articulates the eras of evolution of analytics varying from descriptive, predictive and prescriptive analytics. Process models used for inferring information from data have been compared and their applicability for analyzing big data has also been sought. Finally, recent developments carried in the domain of big data and analytics are compared based on the state-of-the-art approaches.
Lithium-ion is increasingly the technology of choice for battery-powered systems. Current cell performance monitoring, which relies on measurements of full cell voltage and sporadic surface temperature, does not provide a reliable information on the true internal battery state. Here, we address this issue by transforming off the shelf cells into smart systems by embedding flexible distributed sensors for long-term in-situ and operando thermodynamic data collection. Our approach, which enables the monitoring of the true battery state, does not impact its performance. In particular, our results show that this unprecedented methodology can be used to optimise the performance and map the safety limits of lithium-ion cells. We find that the cell core temperature is consistently and significantly higher than the surface temperature, and reveal a breach of safety limits during a rapid discharge test. We also demonstrate an application of a current considerably higher than the manufacturers’ specification, enabling a significant decrease in charging time, without compromising the cell’s thermal stability. Consequently, this work on cell instrumentation methodology has the potential to facilitate significant advances in battery technology.