batterydata/paper-abstracts huggingface dataset:
Through-plane potential and overpotential distributions in a vanadium redox flow battery (VRFB) is investigated in-situ using saturated Ag/AgCl reference electrodes attached to each side of the membrane with edge-type configuration. Combined with electrochemical impedance spectroscopy (EIS), this operando approach enables detailed quantification of the voltage losses contributed from the individual VRFB cell components with the magnitudes of ohmic and charge transfer losses at practical charge-discharge conditions. It is found that the overpotentials for vanadium redox reactions on graphite felt electrodes at the positive and negative half-cells are one order magnitude larger than the voltage loss through the typical cation-exchange membrane (Nafion®117) for charging-discharging at current densities from 50 to 120 mA cm−2. Within the overall half-cell overpotentials, the ohmic voltage loss accounts for about 40%. The analysis reveals that the voltage loss by the anode charge transfer reaction is about three folds larger than that by the cathode reaction, suggesting that sluggish V2+/V3+ redox kinetics in the negative half-cell is the major factor limiting the overall VRFB cell performance. This operando methodology is effective for the in-depth analysis of VRFB performance in practical conditions as well as the development of high-performance cell components and efficient total cell design by a collective and quantitative approach.
The spherical Li[Ni1/3Co1/3Mn1/3]O2 powders with appropriate porosity, small particle size and good particle size distribution were successfully prepared by a slurry spray drying method. The Li[Ni1/3Co1/3Mn1/3]O2 powders were characterized by XRD, SEM, ICP, BET, EIS and galvanostatic charge/discharge testing. The material calcined at 950°C had the best electrochemical performance. Its initial discharge capacity was 188.9mAhg−1 at the discharge rate of 0.2C (32mAg−1), and retained 91.4% of the capacity on going from 0.2 to 4C rate. From the EIS result, it was found that the favorable electrochemical performance of the Li[Ni1/3Co1/3Mn1/3]O2 cathode material was primarily attributed to the particular morphology formed by the spray drying process which was favorable for the charge transfer during the deintercalation and intercalation cycling.
This paper presents the development of a dynamic model of an electric vehicle with motors in all four wheels. The detailed model, is been developed in ADAMS® platform. It has 14 degrees of freedom and in it are included all elements of the actual vehicle such as coil springs, telescopic shock absorbers and pneumatic wheels. The model has been validated experimentally in the actual vehicle, showing the goodness of fit. This dynamic simulator will serve as a test bed for improving vehicle and driver pretesting traction and stability.
This paper reports an in situ XRD study on the multisubstituted intermetallic compound MmNi3.85Mn0.27Al0.37Co0.38 during an electrochemical charge–discharge reaction. Structural data are available through the evolution of the lattice parameters as electrochemical hydrogen absorption desorption proceeds within 0<x≤4.3 H per formula unit and a satisfactory agreement is obtained with ex situ neutron diffraction data previously reported for the parent compound LaNi3.55Mn0.4Al0.3Co0.75. Preliminary results show the existence during discharge of a less expanded β′ phase compared with the fully charged β phase.
Co3O4-based materials are regarded as superior electrode candidates in various energy storage devices due to their high theoretical capacity. Unfortunately, the poor electronic conductivity and huge volume expansion hamper their widespread applications. Therefore, nano-processing and introducing conductive matrix can view as the necessary methods to make Co3O4-based materials better for an advanced supercapacitor electrode. Herein, a dual-template nanocasting technique is proposed to design the ultrafine Co3O4 grains highly-dispersed on the reduced oxide graphene nanosheets (Co3O4/rGO-C), in which cetyltrimethyl ammonium bromide and silicate species are hired as the ideal soft and hard template, respectively. Co3O4 grains with size <10 nm can expose more active sites and thus exert more redox activities to enhance the capacitive performance. In additional, ∼4 nm moderate pores are obtained in Co3O4/rGO-C after the hard template removing, which provides more diffusion channels for ion/electron rapid transport and also effectively alleviates the volume expansion on cycling. Consequently, the Co3O4/rGO-C electrode exhibits a remarkable specific capacitance (709.1 F g−1 at 1 A g−1) and long-term endurance (91.2% after 6000 cycles). Furthermore, an assembled solid-state asymmetric device of Co3O4/rGO-C||rGO delivers a super-high energy-density of 48.2 Wh kg−1 at 750.5 W kg−1. The high energy-density assists two devices in lightning a red light-emitting diode for 340 s. These results evidence the nanocasting strategy as an efficient method to achieve the advanced electrode materials for energy storage devices.
Nanosized Prussian Blue, K0.88Fe2.04(CN)6·yH2O, prepared in aqueous solution at room temperature, is shown to be active as anode for lithium ion batteries after mild dehydration. It exhibits reversible capacities of up to 400 mAh g−1 at 8.75 mA g−1 and 150 mAh g−1 at 1750 mA g−1, with relatively low hysteresis and long cycle life in the low voltage range 0.005–1.6 V vs lithium. Ex-situ XRD, FTIR as well as SEM and TEM studies on pristine and cycled electrodes suggest that the reversible insertion of about ∼5 Li+/f.u. is associated with a displacement (or conversion) reaction on the Prussian Blue structure along with the reduction of all iron atoms, reported for the first time in this kind of systems. The products of re-oxidation do not recover the crystal structure of Prussian Blue.
NASICON-structured Li1.5Al0.5Ge1.5(PO4)3 glass-ceramic is successfully fabricated through melt-quench with post-crystallization. The influence of crystallization temperature on structure and ionic conductivity is studied using X-ray diffraction, nuclear magnetic resonance and impedance analysis, revealing that the Li ion mobility is closely related with crystallization temperature that in turn affects the bulk conductivity. Scanning electron microscopy reveals a progress of transformation from an amorphous phase to a crystalline, and grain growth during the annealing. It is shown that crystallization temperature plays an important role in controlling the ionic conductivity. The highest conductivity of 2.25 × 10−3 S cm−1 with an activation energy of 0.29 eV at room temperature has been obtained for the glass-ceramic specimen crystallized at 825 °C for 8 h.
Hepatocellular carcinoma is a very common neoplastic disease in countries where hepatitis viruses B and/or C are prevalent. Small hepatocellular carcinoma lesions detected by ultrasonography at an early stage are often hyperechoic because they are composed of well-differentiated cancer cells that are rich in triglyceride droplets. The triglyceride content of hepatocytes depends in part on the rate of lipogenesis. Key lipogenic enzymes, such as fatty acid synthase, are co-ordinately regulated at the transcriptional level. We therefore examined the mRNA expression of lipogenic enzymes in human hepatocellular carcinoma samples from 10 patients who had undergone surgical resection. All of the samples exhibited marked elevation of expression of mRNA for lipogenic enzymes, such as fatty acid synthase, acetyl-CoA carboxylase and ATP citrate lyase, compared with surrounding non-cancerous liver tissue. In contrast, the changes in mRNA expression of SREBP-1, a transcription factor that regulates a battery of lipogenic enzymes, did not show a consistent trend. In some cases where SREBP-1 was elevated, the main contributing isoform was SREBP-1c rather than SREBP-1a. Thus, lipogenic enzymes are markedly induced in hepatocellular carcinomas, and in some cases SREBP-1c is involved in this activation.
Computer modelling research has undermined the view that double dissociations in behaviour are sufficient to infer separability in the cognitive mechanisms underlying those behaviours. However, all these models employ multi-modal representational schemes, where functional specialisation of processing emerges from the training process. Targeted lesioning of different regions of functional specialisation leads to varied but predictable deficits in model performance. We argue that multi-modal representational schemes are not a necessary condition for the observation of double dissociations in an information processing system that shares resources across multiple tasks. Using a uni-modal representational system, we demonstrate that double dissociations may also result from stochastic processes. Lesioning experiments on a single-route, uni-modal connectionist model of regular and irregular noun and verb morphology confirm and extend earlier work demonstrating that selective impairment across tasks can result from damage to a distributed information processing system. A systematic investigation of the degree to which performance deteriorates across different inflectional classes reveals that simple and double dissociations can occur in this single-route, uni-modal model. An important prediction of the model is that double dissociations between regular and irregular inflection, resulting from stochastic processes should be extremely rare. However, they are particularly likely to occur when the researcher uses test batteries consisting of a small number of items. Given that cognitive neuropsychologists rarely provide details about the distribution of performance in a disordered population, it is concluded that a stochastic interpretation of double dissociations may have wider applicability than is normally supposed.
The U.S. electrical grid, the largest and most complex man-made system in the world, is highly vulnerable to three types of external threats: 1) natural disasters, 2) intentional physical attacks, and 3) cyber-attacks. The technical community has recommended hardening the grid to make it more resilient to attack by using distributed generation and microgrids. Solar photovoltaic (PV) systems are an ideal distributed generation technology to provide power for such microgrids. However, both the deployment velocity and the policy of how to implement such technical solutions have been given far less attention than would be normally considered adequate for a national security risk. To address this threat, this paper reviews the technical and economic viability of utilizing defense contracting for the beginning of a national transition to distributed generation in the U.S. First, the technical scale of electrical demand and the solar PV system necessary is analyzed in detail to meet the first level of strategic importance: the U.S. military. The results found that about 17GW of PV would be needed to fortify the U.S. military domestically. The current domestic geographic deployment of microgrid installations in the critical U.S. defense infrastructure were reviewed and compared to historical grid failures and existing and planned PV installations to mitigate that risk. The results showed a minimal number of military bases have introduced solar PV systems, leaving large parts of the Department of Defense electrical infrastructure vulnerable to attack. To rectify this situation, the technical skills of the top 20 U.S. defense contractors is reviewed and analyzed for a potential contracting transition to grid fortification. Overall the results indicate that a fortified U.S. military grid made up of PV-powered microgrids is technically feasible, within current contractors skill sets and economically viable. Policy recommendations are made to accelerate U.S. military grid fortification.
In this work, CuS/graphene (CuS-G) composite is synthesized via one-pot microwave irradiation method under ambient conditions. As anode material for lithium ion batteries, the CuS-G composite delivers a significantly enhanced reversible capacity and charge/discharge cycle stability compared with pristine CuS. A capacity of 348mAhg−1 can be maintained after 1000 cycles at the current density of 2.0Ag−1. Electrochemical impedance spectroscopy (EIS) along with cyclic voltammetry (CV) and galvanostatic intermittent titration technique (GITT) measurements indicate that the incorporation of graphene sheets reduces the contact resistance and enhances lithium ion transfer rate during the electrochemical lithium insertion/extraction remarkably. Thus, as-prepared CuS spheres can be a promising anode material for high performance lithium ion batteries.
Despite their relatively high capacity, layered lithium transition metal oxides suffer from crystal and interfacial structural instability under aggressive electrochemical and thermal driving forces, leading to rapid performance degradation and severe safety concerns. Here we report a transformative approach using an oxidative chemical vapour deposition technique to build a protective conductive polymer (poly(3,4-ethylenedioxythiophene)) skin on layered oxide cathode materials. The ultraconformal poly(3,4-ethylenedioxythiophene) skin facilitates the transport of lithium ions and electrons, significantly suppresses the undesired layered to spinel/rock-salt phase transformation and the associated oxygen loss, mitigates intergranular and intragranular mechanical cracking, and effectively stabilizes the cathode–electrolyte interface. This approach remarkably enhances the capacity and thermal stability under high-voltage operation. Building a protective skin at both secondary and primary particle levels of layered oxides offers a promising design strategy for Ni-rich cathodes towards high-energy, long-life and safe lithium-ion batteries.
Li metal was electrodeposited galvanostatically on aLi metal substrate in propylene carbonate (PC) containing 0.5 M lithium perchlorate (LiClO4). The concentration profile of Li+ ion developed with electrodeposition was measured in situ by holographic interferometry. The interference fringe shift at a higher current density indicates that the mass transfer rate of Li+ ion along a vertical cathode is primarily governed by natural convection induced by Li metal electrodeposition. This transient natural convection is reasonably described by the boundary layer theory. However, no interference fringe shift was observed in the initial stage of electrodeposition at a lower current density. The incubation period until the interference fringes start to shift was considerably prolonged as the applied current density was decreased. The charge consumed during the incubation period varied from 7 to 30 mC cm−2. This phenomenon was attributed to the diffusion of residual H2O in the PC electrolyte.
In this paper, we report on the preparation of bare and Mg-doped Li(MgxCo1-x)O2 (x=0, 0.03, 0.05) phases by a molten salt method and their electrochemical properties. They were prepared at 800°C for 6h in air. Rietveld refined X-Ray Diffraction data of bare (x=0) and Mg-doped (x=0.03, 0.05) compounds show a well-ordered hexagonal layer-type structure (a ∼ 2.81Å, c ∼ 14.05Å). Scanning Electron Microscopy (SEM) show hexagonal type morphology at 800°C. Powder density was close to 5.02 gcm−3, which compares well with the theoretical value. Electrochemical properties were studied in the voltage range of 2.5-4.3V vs. Li using Cyclic Voltammetry (CV) and galvanostatic cycling. CV studies on bare and Mg-doped LiCoO2 show main cathodic and anodic redox peaks at ∼ 3.9V and ∼ 4.0V, respectively. Galvanostatic cycling of Li(MgxCo1-x)O2 (x=0, 0.03, 0.05) showed reversible capacity values at the 60th cycle to be: 147 (±3) mAh g−1 (x=0), 127 (±3) mAh g−1 (x=0.03), and 131 (±3) mAh g−1 (x=0.05) cycled at a current density of 30mAg−1. Capacity retention is also favourable at 98.5%.
We report heat capacity, thermogravimetry and thermal diffusivity data for carbonized mesophase pitch coated LiFePO4 (LFP) cathodes. The results are compared with the thermophysical properties of a conventional LFP-based electrode having a poly (vinylene) difluoride (PVDF) binder and conductive carbon diluents. The measured heat capacity of LFP as a function of temperature is in good agreement with model calculations based on first-principles methods. Thermal diffusivity data indicate that the mesophase pitch coated LFP compositions have a factor of two higher thermal diffusivity than the conventional electrode composition, suggesting that the coatings improve heat transfer. In the presence of an electrolyte mixture (1.2 M lithium hexa-fluorophosphate), differential scanning calorimetry (DSC) analysis of the LFP–pitch composite and LFP–PVDF–carbon composites showed similar onset temperature and heat evolution.
Scenarios that limit global warming to 1.5 °C describe major transformations in energy supply and ever-rising energy demand. Here, we provide a contrasting perspective by developing a narrative of future change based on observable trends that results in low energy demand. We describe and quantify changes in activity levels and energy intensity in the global North and global South for all major energy services. We project that global final energy demand by 2050 reduces to 245 EJ, around 40% lower than today, despite rises in population, income and activity. Using an integrated assessment modelling framework, we show how changes in the quantity and type of energy services drive structural change in intermediate and upstream supply sectors (energy and land use). Down-sizing the global energy system dramatically improves the feasibility of a low-carbon supply-side transformation. Our scenario meets the 1.5 °C climate target as well as many sustainable development goals, without relying on negative emission technologies.
The inevitable depletion of non-renewable fossil fuels and serious environmental pollution promote the wide application of renewable energies. Most of the renewable energy sources, such as solar and wind power, suffer from uncontrollable as well as complicated situations (Yang et al., 2011) [1]. Electrochemical energy storage technologies are crucial to solve these problems, as they can efficiently store electricity in chemicals and release it according to the users’ demands (Yang et al., 2011; He et al., 2006)[1,2]. Moreover, energy and environmental challenges have stimulated great interest to replace gasoline engine powered vehicles by plug-in hybrid vehicles (PHEV) and electric vehicles (EVs). Therefore, it is vital to improve the performance of energy storage systems, which depends on the development of key materials for the various batteries and new energy storage strategies. Researchers from Chinese Academy of Science (CAS) have dedicated to the researches of energy storage systems for decades and made significant process. We will introduce the progress on energy storage systems of CAS in recent two years, which covers the key materials of Lithium ion battery (LIB), Lithium-oxygen (Li-O2) battery, Lithium-sulfur (Li-S) battery, Lithium ion capacitor, Sodium ion battery, and Flow battery.
The study of chaotic systems is one of the vital and novel areas of physics. Chaotic systems can be built in the laboratory with electronic components, and one such circuit was proposed by Leon O. Chua. Here, we demonstrate how to simulate Chua’s circuit with LTspice software and obtain different dynamical patterns by changing the resistance parameter in the circuit. All the essential characteristics of a chaotic system are observed in the LTspice simulations of Chua’s circuit in an easy, inexpensive manner, and this greatly helps students explore this new and exciting area of physics.
The influence of the operation conditions temperature and state of charge (SOC) on the performance of a commercial high-power lithium-ion cell is investigated by electrochemical impedance spectroscopy. Based on the results of several preliminary tests, measurements were run covering the complete range of automotive applications. The cell impedance is presented and analyzed. A strong nonlinear temperature correlation is shown for all frequency ranges. Although the ohmic resistance is nearly unaffected by variation in SOC, the mass transport impedance reduces from 100% to 60% SOC and increases significantly again for lower SOCs.
One dimensional porous binary metal oxides exert much more attention for electrochemical energy conversion and storage applications. Herein, we report a simple process for the synthesis of one dimensional mesoporous rod-like NiCo2O4 structure (NCO NRs) grown on reduced graphene oxide sheets (RG/NCO NCs). This noble metal free RG/NCO NCs composite manifested as the dual-functional electrode material for the electrochemical oxygen evolution reaction (OER) and supercapacitor applications. The RG/NCO NCs shows significant OER performance with prosperous reaction kinetics with a smaller Tafel slope of 35 mV dec−1. It requires only 313 mV overpotential to deliver 10 mA cm−2 current density, showing superior OER activity compared to some of the state-of-art electrocatalysts under similar electrochemical conditions. Moreover, the RG/NCO NCs showed enhanced energy storage efficacy in terms of higher specific capacitance (1315 F g−1), long-term operational durability, higher specific energy and power output. The porous structure, higher specific surface area and better electrochemical conductivity of the RG/NCO NCs make it a suitable material for both the energy conversion and storage application. Additionally, to validate the supercapacitor performance, a prototype device in coin cell configuration has been designed and successfully tested to power a LED.
Potassium nickel hexacyanoferrate KNi[Fe(CN)6] (NiHCF) was synthesized by a simple co-precipitation method and investigated as a cathode material for lithium-ion batteries. The X-ray diffraction and transmission electron microscopy studies revealed the formation of pure phase of agglomerated NiHCF nanoparticles of about 20–50nm in size. The material exhibited stable cycling performance as a cathode in a lithium half-cell within a wide range of current densities, and a working potential around 3.3V vs. Li+/Li. The lithium ion diffusion coefficient in this system was determined to be in a range of 10−9 to 10−8 cm2 s−1, which is within the values for the cathode materials for lithium-ion batteries with high rate capability. Considering promising electrochemical performance and attractive lithium-ion diffusion properties of this material along with its economical benefits and simplified preparation, NiHCF could be considered as a very promising cathode for large scale lithium-ion batteries.