batterydata/paper-abstracts huggingface dataset:
The reaction evolution and kinetics of the LiFePO4 positive electrode material is dependent on the synthesis method and cycling conditions. In operando neutron powder diffraction is used investigate the structure-electrochemistry relationship of the electrode materials in a Valence Technology Inc. 18650 Energy cell (IFR18650EC) containing a graphite negative electrode and a Mg-doped LiFePO4 (Li(MgFe)PO4) positive electrode. Two cells were studied at ambient (298 K) and elevated (323 K) temperature, and higher temperatures were found to improve reaction kinetics and hence capacity. Rietveld refinement of structural models against the diffraction data revealed information about the nucleation of the lithiated and delithiated phases in the Li(MgFe)PO4 positive electrode material as a function of each cell's state of charge. Polarisation was indicated by a shift in the potential at which the lithiated and delithiated (MgFe)PO4 phases nucleate during cycling, the extent of which was found to be linearly proportional to the applied current. This work provides new evidence for polarisation of the positive electrode material in a Li-ion battery system.
Silver terephthalate (Ag2TP) with the theoretical specific capacity of 141mAhg−1 was intentionally employed as the organic anode in Li-ion and Na-ion batteries respectively, aiming to in-situ generate the conductive metallic particles from the easily-reducible Ag+ cations. Meanwhile, the conveniently-synthesized Ag2TP solids inherently exhibited nanosized objects without any post treatment. Based on these advantages, the Ag2TP anode in Li-ion battery could exhibit discharge capacity of average 149mAhg−1 at 1C for 500 cycles, maintaining as high as 113mAhg−1 at the 500th cycle; while the Ag2TP anode in Na-ion battery still displayed similar value of average 133mAhg−1 at 1C for 100 cycles. These results could represent the new advancement among the organic electrodes of terephthalate salts.
By replacing traditional liquid organic electrolyte with solid-state electrolyte, the solid-state lithium batteries powerfully come back to the energy storage field due to their eminent safety and energy density. In recent years, a variety of solid-state lithium batteries based on excellent solid-state electrolytes are developed. However, the performance degradation of solid-state lithium batteries during cycling and storing is still a serious challenge for practical application. Therefore, this review summarizes the research progress of solid-state lithium batteries from the perspectives of failure phenomena and failure mechanisms. Additionally, the development of methodologies on studying the failure mechanisms of solid-state lithium batteries is also reviewed. Moreover, some perspectives on the remaining questions for understanding the failure behaviors and achieving long cycle life, high safety and high energy density solid-state lithium batteries are presented. This review will help researchers to recognize the status of solid-state lithium batteries objectively and attract much more research interest in conquering the failure issues of solid-state lithium batteries.
The rate constants for the self-discharge of the cathode material nickel(III) oxyhydroxide (NiOOH) in an alkaline medium are determined using a galvanostatic titration technique. By examination of a number of common graphite materials used in battery cathodes it is found that both the type and the amount of graphite present in the electrode influence the self-discharge rate. Two competing self-discharge phenomena exist, namely, reaction of NiOOH with surface active sites on the graphite, as well as the graphite catalyzing oxygen evolution. Their respective contributions to the overall self-discharge are evaluated.
An accelerated method was used to determine the effect of temperature, end-of-charge voltage and the type of storage condition over the performance pouch lithium-ion cells. The cells were studied for 4.0V and 4.2V end-of-charge voltages (EOCV) both at 5°C and 35°C. The irreversible capacity loss of the cell was analyzed every month using a capacity measurement protocol. The results indicated that higher temperature and voltage accelerates the degradation of the cells. The open circuit voltage (OCV) decay of the cells stored under open circuit conditions was also analyzed. The reasons for the irreversible capacity loss, energy loss, OCV decay and the increase in the internal resistance of the cell are discussed in detail. The most detrimental storage condition and the most mild storage condition are identified and discussed in detail.
An ODYSSEY autonomous underwater vehicle (AUV) was deployed in Massachusetts and Cape Cod Bays in September 1998 to collect chlorophyll fluorescence, optical backscattering (880nm), and physical data. It sampled the region mainly in a sawtooth pattern with horizontal resolution between ∼120m at the middle of the water column and with vertical resolution of 0.1m. The data were used to quantify various features in both physical and bio-optical properties in the Bays. In particular, an upwelling front with enhanced chlorophyll fluorescence was found off the coast of Race Point. Chlorophyll patches with along-track spatial scales less than 3.6km were found southeast of Plymouth and southwest of Race Point. Southeast of Plymouth, strong sediment re-suspension was also evident. In the early fall, the water column was characterized by three layers: warm and fresh surface water; cold and salty bottom water; and a transition (pycnocline) layer with sharp vertical temperature and salinity gradients. A relatively thin chlorophyll maximum layer was evident in the strong pycnocline. This work represents one of the first successful applications of AUVs for interdisciplinary coastal research. Our results demonstrate that AUVs can provide high-quality, concurrent measurements of physical and bio-optical properties in a very effective manner. Some future uses of AUVs are suggested.
A methacrylate based gel polymer electrolyte (GPE) was prepared and electrochemically investigated. The polymer was synthesized as a statistical co-polymer of oligo(ethylene glycol) methyl ether methacrylate (OEGMA) and benzyl methacrylate (BnMA) by free radical polymerization. The ethylene glycol side chain of OEGMA should be able to interact with the liquid electrolyte, thus keeping it inside the GPE, whereas BnMA was used to enhance the mechanical stability of the GPE. Such a polymer was able to retain liquid electrolyte up to 400% of its own weight, while the mechanical stability of the GPE was still high enough to be used as separator in lithium-ion batteries. The GPE displayed a conductivity of 1.8 mS cm−1 at 25 °C and an electrochemical stability window comparable to that of a standard liquid electrolyte. When used in lithium-ion batteries, such a GPE allowed a performance comparable to that obtained using conventional liquid electrolytes. Therefore the reported electrolyte was identified as a promising candidate as electrolyte for lithium-ion batteries.
Orthorhombic LiMnO2 cathodes suffer severe capacity fading due to accelerated manganese dissolution at elevated temperatures. Fluorine-modified LiMnO2 cathodes prepared by a solid-state reaction show less cation mixing and a well-defined crystallinity with a larger grain/powder morphology. The cathodes exhibit improved capacity retention and rate capability at the elevated temperature (55°C) compared with undoped counterparts.
A new hybrid nanostructure of porous cobalt monoxide nanowire @ ultrathin nickel hydroxidenitrate nanoflake is directly synthesized on a 3D nickel foam by a facile two-step hydrothermal route, which demonstrates a specific capacitance of ∼798.3 F g−1 at the current density of ∼1.67 A g−1 and good rate performance when used as electrode material for supercapacitors. The capacitance loss is less than 5% after 2000 charge–discharge cycles.
Recently, context-aware applications, which provide customized services using personalized contextual information, have gained much attention. However, core IT technologies for realizing context-aware services are not sufficient to support the actual development of context-aware applications. Especially, it is very hard to find studies on context-aware data modeling that can provide different responses even for the same information according to users’ situation. In practice, most context-aware services are managing contextual information in the phase of application development in a rather ad-hoc way. Unfortunately, this approach has an obvious limitation of expansibility when the amount of rapidly increasing contextual information is considered. In this paper, we first define the concept of contextual dependency among data objects. Second, we provide a context-aware data modeling methodology for modeling contextual information into the Entity-Relationship Diagram (ERD, for short) based on contextual dependency. Finally, we design a simple scenario for context-aware services, construct an ERD from the scenario based on the discovered design rules, and implement a prototype of the service.
This article elaborates a techno-economic approach that aims to optimize the conversion and energy storage unit chain of the first quick charge plug-in ferry. The choice of supercapacitors is motivated and then compared to other energy storage units for different kind of ferry exploitation. Several models were developed to be coupled with a global techno-economic model considering an exploitation strategy. In the last part, a typical application illustrates the cost reduction compared to the standard sizing approach.
This paper investigates how the aging of lithium-ion batteries is influenced by the superimposition of an AC waveform on a discharge current. Based on the results of two experiments on LiCoO2 cells, the root mean square (RMS) value of the discharge current is determined to be a significant aging factor, while evidence does not support the importance of either the DC current value, waveform shape or frequency for battery aging. The practical significance of this result lies in the recognition of the importance of passive filtering or other means to reduce the AC component of the battery pack discharge current. Furthermore, a quantitative analysis is provided to numerically determine the aging effect of the RMS current factor. Such quantitative results can provide valuable guidelines for designing features such as battery pack filters using DC bus capacitors. The design of experiments and associated analyses presented in the paper can also be adopted for the investigation of other battery aging factors of interest.
It is essential to boost the catalytic activity and cycling stability of the electrode for the ultra-long-term operation of vanadium flow battery (VFB). Herein, we report a novel hierarchical electrode by coating carbon spheres on the graphite felt (CS/GF) employing silicon dioxide nanospheres as templates and phenol formaldehyde resin as carbon sources. CS/GF possess larger surface areas and more defects than the thermally activated graphite felt, leading to better wettability and more active sites. As a result, the electrochemical activity and kinetic reversibility of the CS/GF electrode toward the VO2 +/VO2+ and V3+/V2+ redox couples are promoted. Meanwhile, the novel carbon layer-confined structure ensures the superior durability of the CS/GF electrode during the ultra-long-term cycling test. The VFB assembled with CS/GF electrode exhibits outstanding rate performance at current densities of 50–300 mA cm−2 as well as excellent stability over 5000 charge-discharge cycles at a high current density of 150 mA cm−2. The facile method in this work provides a new idea for developing efficient and durable VFB electrodes.
The redox efficiency of iron has been improved by increasing the distribution of iron on the carbon surface with Fe2O3-loaded carbon materials. The Fe2O3-loaded carbon material was prepared by loading Fe2O3 on carbon by a chemical method. Fe(NO3)3 was impregnated on carbon with different weight ratios of iron-to-carbon in an aqueous solution, and the mixture was dried and then calcined for 1h at 400°C in flowing Ar. The effect of various carbons on the physical and electrochemical properties of Fe2O3-loaded carbon electrodes was investigated with the use of X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) along with X-ray energy-dispersive spectroscopy (EDS), cyclic voltammetry (CV) and galvanostatic cycling performance. Transmission electron microscopy coupled with X-ray diffraction measurements revealed that small Fe2O3 particles were distributed on the carbon surface. Natural graphite and several nano-carbon materials such as acetylene black and tubular carbon nanofibers (tubular CNF) exhibited improved characteristics, such as enhanced capacity and higher redox currents for the Fe2O3-loaded carbon electrode. SEM and EDS results suggest that Fe2O3-loaded nano-carbon electrodes, due to the large surface area of the nano-carbon, have more Fe2O3 dispersed than on Fe2O3-coated graphite electrodes.
This paper considers the scaling principles associated with the power and energy density of batteries and generators as applied to mobile robots and similarly-sized vehicles. We seek to identify, based on present technology, the size range at which a generator inclusive of a direct current electric motor, gearbox, and internal combustion engine can be effectively used to replace modern batteries. Models were derived to scale each component of the generator as a function of power, mass, efficiency, and speed. For a given power, energy, or mass requirement, these models illustrate that generators based on conventional technology are ill-suited for smaller robots. The results indicate that there is an intermediate robot size above which a hybrid generator/battery architecture is desirable. Using these scaling principles with modest extensions of existing battery technologies, it is also possible to infer the near-future performance of robot power technology and thus illustrate whether the generator-versus-battery tradeoff will shift toward or away from a hybrid robot topology for smaller vehicle systems.
Hybrid DC power sources which consist of fuel cells, photovoltaic and lithium-ion batteries provide clean, high efficiency power supply. This hybrid DC power sources can be used in many applications. In this work, a model-based fault detection methodology for this hybrid DC power sources is presented. Firstly, the dynamic models of fuel cells, photovoltaic and lithium-ion batteries are built. The state space model of hybrid DC power sources is obtained by linearizing these dynamic models in operation points. Based on this state space model the fault detection methodology is proposed. Simulation results show that model-based fault detection methodology can find the fault on line, improve the generation time and avoid permanent damage to the equipment.
In this contribution, we report for the first time a novel potassium ion-based dual-graphite battery concept (K-DGB), applying graphite as the electrode material for both the anode and cathode. The presented dual-graphite cell utilizes a potassium ion containing, ionic liquid (IL)-based electrolyte, synergetically combining the extraordinary properties of potassium, graphite and ILs in terms of cost effectiveness, sustainability and safety. The IL electrolyte shows a very stable cycling performance in combination with the graphite anode at a so far not reported reversible capacity of ≈230 mA h g−1. A highly reversible capacity of >42 mA h g−1 (with respect to the graphite cathode) even at a current of 250 mA g−1, and a Coulombic efficiency (CE) exceeding 99% in a potential range from 3.4 V to 5.0 V vs. K/K+ represent the corner pillars of this innovative battery technology. The very promising electrochemical performance is further emphasized by a capacity retention of 95% after 1500 cycles. Furthermore, the electrochemical formation of a stage-1 potassium graphite intercalation compound (K-GIC) from an IL electrolyte, resulting in a stoichiometry of KC8 is presented in this work for the first time. The presented results shed new light on an alternative energy storage technology, especially in view of stationary (“grid”) energy storage by employing environmentally friendly, abundant and recyclable materials.
This article evaluates the methods to characterise the behaviour of lithium ion cells of several chemistries and a nickel metal hydride cell for automotive applications like (plug-in) hybrid vehicles and battery electric vehicles. Although existing characterisation test methods are used, it was also indicated to combine test methods in order to speed up the test time and to create an improved comparability of the test results. Also, the existing capacity tests ignore that cells can be charged at several current rates. However, this is of interest for, e.g. fast charging and regenerative braking. Tests for high power and high energy application have been integrated in the enhanced method. The article explains the rationale to ameliorate the test methods. The test plan should make it possible to make an initial division in a group of cells purchased from several suppliers.
Summary The hearing aid is extremely important to the deaf. A small number have difficulty in retaining the device because the ear is prominent or cup-shaped. This report describes 11 children whose ear shape was modified to improve hearing aid retention and one adult in whom an over set back ear was released to allow fitment of a postaural device. In eight of the 11 children treated, conservative measures such as double-sided tape and retention bands (Huggies™) had been tried previously without success. The creation of an antihelical fold in a misshapen ear lacking such a fold provides a reinforcing strut which is useful to support a hearing aid. In patients whose ear had been excessively tethered by previous surgery, projection was restored by inserting a cartilage block behind the ear. In one child with ears tethered by previous surgery, costal cartilage was used not only to release both ears, but also to reconstruct a new helical rim on one side. Surgery enabled a normal postaural hearing aid to be worn in 17 of the 19 ears treated. The two failures deserve special mention. In one patient with a unilateral deformity and severe mental retardation, the dressings were pulled off immediately after surgery. In another patient with a bilateral problem, the appearance and hearing aid retention was improved, but there was not enough room in the postauricular sulcus on one side for the battery component to fit comfortably and an in-the-ear device is now used on that side. Pinnaplasty is a helpful strategy to improve hearing aid retention. Care must be taken not to overdo the set back so that enough room is left to retain the hearing device.
This work describes the evolution of α-Fe2O3 nanowires during the conversion reaction associated with lithium intercalation. An electrical resistive heating method synthesizes single crystal hematite (α-Fe2O3) nanowires. Transmission electron microscopy characterizes this anode material at various stages of lithiation and delithiation. The process initiates through the reduction of α-Fe2O3 to nanocrystalline Fe3O4. Further lithiation converts all of the iron oxide to nanocrystalline BCC Fe. During delithiation, the reactions proceed via conversion of Fe0 to Fe2O3. However, a nanocrystalline structure replaces the initial single crystalline α-Fe2O3 after the first circle. This polycrystalline nanowire structure persists for over 30 cycles.
The effect of metal sulfides in the cathode on Na/S battery performance was investigated. Battery capacity was heavily decreased by doping with FeS2, CoS2 and Cr2S3, and little influenced by doping with NiS2 and Al2S3. A FeS2 3.0wt.% doped cell exhibited a 65% resistance rise and a 65% capacity loss during cycling. Such a degradation causing by the metal sulfides was mainly attributable to a low charge acceptability of the cathode and closely related to the cathode structure.
The electrochemical and charge/discharge behaviors of cobalt oxide prepared by the calcination of cobalt hydroxide were studied by the cyclic voltammetry (CV) and galvanostatical charge/discharge methods. The cyclic voltammograms of cobalt oxide containing 20% carbon black were correlated well with the results in the charge/discharge behaviors of Li/CoO batteries. A cathodic peak with potential of 0.5V (versus Li/Li+) in the first cycle of CV corresponded to the plateau with voltage of 1.0–0.8V in the first discharge cycle of Li/CoO battery was deduced to be the reduction and decomposition of CoO particle to be the nano-sized Co and Li2O. Both of the cathodic peak and the discharge plateau voltages were shifted to higher values in the following cycles due to the reduction of CoO particle from micro to nano-size.
The electrochemical intercalation of lithium has been studied by cyclic voltammetry experiments at single wall carbon nanotubes (SWCNTs) chemically attached at Pt electrodes with 4-aminothiophenol (4ATP). Cyclic voltammetric studies of Li+ at SWCNT/4ATP/Pt electrodes were done evaluate the reversibility of Li intercalation. High-resolution X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, and reflection–absorption infrared spectroscopy were done to characterize the structural changes of SWCNTs/4-ATP/Pt electrodes upon electrochemical lithium intercalation. The reversible energy capacity obtained from charge/discharge studies showed a change from 538mAh/g at the first charge/discharge cycle to 703mAh/g, at the fifth cycle. The calculated Li storage capacity for SWCNTs/4-ATP/Pt electrodes almost doubled the theoretical capacity for Li intercalation in graphite electrodes.
Two kinds of composite, based on poly(ethylene oxide) (PEO) and a mineral saponite, were prepared and their thermal behavior, phase composition, microstructure and electrical properties were investigated. The results showed that PEO easily intercalates to the interlayer of saponite, replaces the interlayer water molecules, and acts as medium for lithium ions conduction. PEO-intercalated saponite exhibited conductivity as high as 4.1×10−3 Scm−1, a lithium ion transference number of 0.99 at 25°C and conductivity activation energy of 0.14eV. Appropriate amounts of intercalated PEO in the interlayer of saponite is important to an ideal ionic conductivity. The PEO-intercalated saponite is thermally stable below 350°C. In addition, a PEO-based composite with lithium saponite as filler showed a homogeneous morphology and combined properties of individual PEO and saponite. The PEO-intercalated saponite could be considered as a good candidate as filler for lithium conductive polymer electrolyte.
A hard carbon (HC) prepared from phenolic resins is investigated as a potential electrode material for power Li-ion batteries and hybrid supercapacitors. The electrochemical test results indicate that the HC is capable of delivering a capacity of 526 mAh g−1 (about 40% greater than graphite) with an initial coulombic efficiency of 80%. The constructed Li(Ni1/3Co1/3Mn1/3)O2/HC full cells shows superior power capabilities, retaining 90% of reversible capacity at a discharge rate as high as 30 C. That is equivalent to a specific energy of 98 Wh kg−1 at a power of 3000 W kg−1. When combined with an activated carbon (AC), the constructed AC/HC hybrid capacitor exhibits a specific capacitance of 21.5 F g−1 or energy density of 22.6 Wh kg−1 (considering the weight of all components of the full cell) at a current of 100 mA g−1. At a power of 480 W kg−1, it delivers an energy density of 20.8 Wh kg−1, which is twice that of a conventional AC/AC supercapacitor. The feature of high energy and power capabilities makes HC materials promising candidates as electrodes for energy storage and conversion application.