batterydata/paper-abstracts huggingface dataset:
Widespread adoption of smart IoT devices is accelerating research for new techniques to make IoT applications secure, scalable, energy-efficient, and capable of working in mission-critical use cases, which require an ability to function offline. In this context, the novel combination of distributed ledger technology (DLT) and distributed intelligence (DI) is seen as a practical route towards the decentralisation of IoT architectures. This paper surveys DI techniques in IoT and commences by briefly explaining the need for DI, by proposing a comprehensive taxonomy of DI in IoT. This taxonomy is then used to review existing techniques and to investigate current challenges that require careful attention and consideration. Based on the taxonomy, IoT DI techniques can be classified into five categories based on the factors that support distributed functionality and data acquisition: cloud-computing, mist-computing, distributed-ledger-technology, service-oriented-computing and hybrid. Existing techniques are compared and categorized mainly based on related challenges, and the level of intelligence supported. We evaluate more than thirty current research efforts in this area. We define many significant functionalities that should be supported by DI frameworks and solutions. Our work assists system architects and developers to select the correct low-level communication techniques in an integrated IoT-to-DLT-to-cloud system architecture. The benefits and shortcomings of different DI approaches are presented, which will inspire future work into automatic hybridization and adaptation of DI mechanisms. Finally, open research issues for distributed intelligence in IoT are discussed.
Unattended Wireless Sensor Networks (UWSNs) operate in autonomous or disconnected mode: sensed data is collected periodically by an itinerant sink. Between successive sink visits, sensor-collected data is subject to some unique vulnerabilities. In particular, while the network is unattended, a mobile adversary (capable of subverting up to a fraction of sensors at a time) can migrate between compromised sets of sensors and inject fraudulent data. In this paper, we provide two collaborative authentication techniques that allow an UWSN to maintain integrity and authenticity of sensor data–in the presence of a mobile adversary–until the next sink visit. Proposed schemes use simple, standard, and inexpensive symmetric cryptographic primitives, coupled with key evolution and few message exchanges. We study their security and effectiveness, both analytically and via simulations. We also assess their robustness and show how to achieve the desired trade-off between performance and security.
The electrochemical behavior of SiO negative electrodes for lithium ion batteries is thermodynamically and experimentally investigated. The analysis of the reaction pathway and the calculation of the reaction potentials during the Li insertion/extraction reactions are carried out by the construction of the ternary phase diagram for the Li–Si–O system. In the initial reaction of Li insertion, metallic Si and lithium silicates are formed above 0.37 V vs. Li/Li+ as a conversion reaction of the SiO negative electrode. Further Li insertion produces Li–Si alloys as reversible reaction phases. The decomposition of the Li4SiO4 phase begins before the formation of the Li–Si alloy is completed. The measured electrode behavior of the SiO negative electrode basically agrees with the thermodynamic calculations, especially at a low reaction rate; deviations can be ascribed to kinetic factors and electrode resistance. The values of over 1898 mA h g−1 and 71.0% were obtained for the discharge capacity and the coulombic efficiency, respectively. Furthermore, the overvoltage for an amorphous SiO electrode was smaller than that for a disproportionated SiO electrode into Si and SiO2 phases.
Energy storage is increasingly seen as a valuable asset for electricity grids composed of high fractions of intermittent sources, such as wind power or, in developing economies, unreliable generation and transmission services. However, the potential of batteries to meet the stringent cost and durability requirements for grid applications is largely unquantified. We investigate electrochemical systems capable of economically storing energy for hours and present an analysis of the relationships among technological performance characteristics, component cost factors, and system price for established and conceptual aqueous and nonaqueous batteries. We identified potential advantages of nonaqueous flow batteries over those based on aqueous electrolytes; however, new challenging constraints burden the nonaqueous approach, including the solubility of the active material in the electrolyte. Requirements in harmony with economically effective energy storage are derived for aqueous and nonaqueous systems. The attributes of flow batteries are compared to those of aqueous and nonaqueous enclosed and hybrid (semi-flow) batteries. Flow batteries are a promising technology for reaching these challenging energy storage targets owing to their independent power and energy scaling, reliance on facile and reversible reactants, and potentially simpler manufacture as compared to established enclosed batteries such as lead–acid or lithium-ion.
A carbonaceous thin film electrode was prepared by plasma-assisted chemical vapor deposition, and lithium-ion transfer at the interface between the resultant thin film electrode and the electrolyte was studied by AC impedance spectroscopy. On the Nyquist plots, semi-circles assigned as charge (Li+ ion) transfer resistance were observed in the intermediate frequency region. The charge-transfer resistance was dependent on electrode potential. The activation energy for lithium-ion transfer through interface between the electrode and the electrolyte was evaluated, and the value was very large. Hence, it is concluded that a high-energy barrier of activation exists at the interface between the electrode and the electrolyte.
Meratrim is a blend of two plant extracts obtained from Sphaeranthus indicus flower heads and Garcinia mangostana fruit rinds. Previous studies have demonstrated that Meratrim is effective for weight management in obese individuals. The objective of this study was to assess the efficacy and tolerability of Meratrim in managing body weight in healthy overweight subjects.
The interfacial layer formed between a lithium-ion conducting solid electrolyte, Li7La3Zr2O12 (LLZ), and LiCoO2 during thin film deposition was characterized using a combination of microscopy and electrochemical measurement techniques. Cyclic voltammetry confirmed that lithium extraction occurs across the interface on the first cycle, although the nonsymmetrical redox peaks indicate poor electrochemical performance. Using analytical transmission electron microscopy, the reaction layer (∼50nm) was analyzed. Energy dispersive X-ray spectroscopy revealed that the concentrations of some of the elements (Co, La, and Zr) varied gradually across the layer. Nano-beam electron diffraction of this layer revealed that the layer contained neither LiCoO2 nor LLZ, but some spots corresponded to the crystal structure of La2CoO4. It was also demonstrated that reaction phases due to mutual diffusion are easily formed between LLZ and LiCoO2 at the interface. The reaction layer formed during high temperature processing is likely one of the major reasons for the poor lithium insertion/extraction at LLZ/LiCoO2 interfaces.
The electrochemical performance of lithium–sulfur batteries with LiClO4 DOL/DME as electrolyte was investigated. Impedance and SEM analysis indicated that too high content of DME(Dimethoxy ethane) in electrolyte could raise the interfacial resistance of battery due to the impermeable layer formed on the surface of the sulfur cathode, which led to bad cycle performance, while the increase of DOL(1,3-dioxolane) could change those phenomena. The optimal composition of electrolyte was DME:DOL = 2:1 (v/v). With this electrolyte, the lithium–sulfur battery obtained a high initial discharge capacity of 1,200 mA h g−1 and still remained 800 mA h g−1 after 20 cycles.
A mesoporous MoSe2/C composite is synthesized through a nano-casting technique along with heat treatment. Nano-silica particles are used as templates to create mesopores. Homogeneously dispersed Molybdenum and selenium particles in the starch substrate are reacted with each other to formed MoSe2 nanosheets when subjected to heat-treatment. Meanwhile, the starch is carbonized into carbon. The mesoporous MoSe2/C composite is investigated as an anode material for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). It presents good storage capacity for both lithium ions and sodium ions. Under the current density of 200 mA g−1, the mesoporous MoSe2/C composite exhibits reversible capacity of 618 mA h g−1 for LIBs and 360 mA h g−1 for SIBs after 300 cycles. The superior electrochemical performance could be ascribed to the mesoporous structure of MoSe2/C composite which provides sufficient space for accommodating huge volumetric expansion and the charge product, selenium.
Solid state electrolytes are of great importance in electrochemical devices such as lithium ion batteries and dye sensitized solar cells as they are safer and eliminate the need for extensive sealing issues. Polyethylene oxide (PEO) is a known solid electrolyte for Li ion batteries; however, its mechanical strength starts deteriorating at higher temperatures. In this work we have used electrospinning technique to form PEO nano-fiber mats with a novel cellulosic reinforcement material named GELPEO. The reinforced fiber mats show a two-fold increase in the tensile strength and up to five times increase in the Young's modulus. Thermal behavior studies revealed that the electrolyte is stable at temperatures above 200 °C and thus can be safely used in Li batteries. Scanning electron microscope (SEM) images showed formation of thinner fibers with the addition of GELPEO in PEO. Ionic conductivity of the order of 10−4 S/cm is achieved for both PEO and PEO/GELPEO samples at 100 °C.
Lithium loss resulting from positive electrode deterioration and lithium accumulation within the solid electrolyte interphase (SEI) at the negative electrode leads to charge capacity loss in lithium-ion batteries (LIBs). We present a novel method to quantify origins of capacity loss resulting from positive electrode degradation and lithium immobilization within the SEI by comparative lithium depth profiles using Lithium Nuclear Reaction Analysis (Li-NRA). Li(Ni0.4Mn0.4Co0.2)O2/artificial graphite (NMC442/AG) pouch cells were cycled with electrolytes containing 1M LiPF6 in either 1:1 ethylene carbonate (EC)/dimethyl carbonate (DMC) or DMC with 3% vinylene carbonate (VC) SEI former. Lithium accumulated rapidly within the SEI in cells containing EC as compared to cells containing VC. Lithium loss from the positive electrode occurred at a linear rate, after formation, which was independent of electrolyte composition tested. The technique and methods provide quantitative insight into the impact of materials on capacity loss.
Nuclear medicine procedures are part of the evaluation armamentarium used in patients with suspected or confirmed infection. The strength of functional imaging modalities rests on their being non-invasive tests that provide pathophysiological information early in the course of disease. Their limitations, related to a somewhat low specificity of radiotracers and image resolution, have largely been overcome over the last 15 years following the introduction of the hybrid SPECT/CT technology. SPECT/CT is redefining the diagnostic workup of patients with suspected or known infectious and inflammatory processes involving the musculoskeletal system as well as those with infectious and inflammatory disease located in various soft-tissue sites. Furthermore, it has been shown that in addition to improving diagnostic accuracy (by adding specificity to the inherent high sensitivity of single-photon emission tomography), SPECT/CT leads to changes in the subsequent clinical management of patients. The main indications for SPECT/CT in infection, as well as updated literature data on this topic, are presented in the following review.
LiBH4-based complex hydrides have attracted much attention as solid electrolytes that are highly compatible with Li metal anode, because of their reducing character and deformable nature. However, the compatibility of LiBH4-based complex hydrides following the formation of a stable interface with Li metal has not yet been fully verified. In this study, electrochemical and mechanical stabilities of LiBH4 and Li4(BH4)3I complex hydride solid electrolytes against Li metal were investigated. Li plating/stripping test performed for 100 cycles and cyclic voltammetry indicated their favorable electrochemical stabilities. Scanning electron microscopy and fast charge–discharge tests revealed the formation of a mechanically tight and durable interface between these solid electrolytes and the Li metal anode. To demonstrate the adequacy of the LiBH4-based complex hydride solid electrolyte for all-solid-state batteries with Li metal anode, an all-solid-state Li–S battery with a Li4(BH4)3I solid electrolyte was assembled and electrochemically tested. The battery showed reversible discharge and charge abilities. This study provides useful insights into a strategy that can be applied to develop complex hydride solid electrolytes.
ABSTRACT In this paper we report a novel architecture of three-dimension (3D) carbon framework to encapsulate tetrahedron ZnO nanocrystals that serves as an anode material for lithium-ion batteries (LIBs). The ZnO@C composites are prepared via a simple internal-reflux method combined with subsequent calcination in argon. The amorphous carbon is formed on the surface of the ZnO crystals by in situ carbonization of the surfactant, which leads to a strong connection between the carbon framework and the active materials and guarantees faster charge transfer on the electrode. The ZnO crystal calcined at 500°C (ZnO@C-5) possesses regular tetrahedron shape with a side length of 150-200nm and all of them are uniformly anchored among the network of amorphous carbon. The developed ZnO@C structures not only improve the electronic conductivity of the electrode, but they also offer a larger volume expansion of ZnO during cycling. As a result, the ZnO@C-5 demonstrates a higher reversible capacity, ultralong cycle life and better rate capability than that of the ZnO@C-7 and pure ZnO crystals. After 300 cycles, the ZnO@C-5 demonstrates a high capacity of 518mAhg−1 at a current density of 110.7mAg−1. Moreover, this simple approach prepared the 3D composites architecture could shed light on the design and synthesis of other transition metal oxides for energy storage.
Concussion, or mild traumatic brain injury, incidence rates have reached epidemic levels and impaired postural control is a cardinal symptom. The purpose of this review is to provide an overview of the linear and non-linear assessments of post-concussion postural control. The current acute evaluation for concussion utilizes the subjective balance error scoring system (BESS) to assess postural control. While the sensitivity of the overall test battery is high, the sensitivity of the BESS is unacceptably low and, with repeat administration, is unable to accurately identify recovery. Sophisticated measures of postural control, utilizing traditional linear assessments, have identified impairments in postural control well beyond BESS recovery. Both assessments of quiet stance and gait have identified lingering impairments for at least 1 month post-concussion. Recently, the application of non-linear metrics to concussion recovery have begun to receive limited attention with the most commonly utilized metric being approximate entropy (ApEn). ApEn, most commonly in the medial-lateral plane, has successfully identified impaired postural control in the acute post-concussion timeframe even when linear assessments of instrumented measures are equivalent to healthy pre-injury values; unfortunately these studies have not gone beyond the acute phase of recovery. One study has identified lingering deficits in postural control, utilizing Shannon and Renyi entropy metrics, which persist at least through clinical recovery and return to participation. Finally, limited evidence from two studies suggest that individuals with a previous history of a single concussion, even months or years prior, may display altered ApEn metrics. Overall, non-linear metrics provide a fertile area for future study to further the understanding of postural control impairments acutely post-concussion and address the current challenge of sensitive identification of recovery.
Graphene oxide (GO) based glassy carbon (GC) electrode has been prepared. Firstly, p-nitrophenyl (NP) modified GC (NP/GC) electrode was prepared via the electrochemical reduction of its tetraflouroborate diazonium salt. After the formation of NP/GC electrode, the negative potential was applied to NP/GC electrode to reduce the nitro groups to amine. p-Aminophenyl (AP) modified GC (AP/GC) electrode was immersed into a graphene oxide solution containing 1-ethyl-3(3-(dimethlyamino)propyl)-carbodiimide. Hence, we constructed GO terminated AP modified GC (GO/AP/GC) electrode. NP/GC, AP/GC and GO/AP/GC electrodes were characterized sequentially using cyclic voltammetry (CV) in the presence of 1.0mM of potassium ferricyanide in 0.1M KCl. In addition, GO and GO/AP/GC surfaces were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The GO/AP/GC electrode was used for the analysis of Cd(II) and Cu(II) ions by adsorptive stripping voltammetry. The linearity range and the detection limit of Cd(II) and Cu(II) ions were 1.0×10−11–5.0×10−10 M and 3.3×10−12 M (S/N=3), respectively.
This work applies in situ Auger electron spectroscopy and X-ray photoelectron spectroscopy to the study of surface redox on LiNi1/3Mn1/3Co1/3O2 during charging and overcharging. We observe that all three transition metals are surface redox active, and that oxygen oxidation occurs for voltages above ≈4.2 V O2 loss above ≈4.7 V, mediated by carbon redox, leads to partial reduction of the transition metals at the surface during overcharging.
Recently, different and unexpected electrochemical behaviours have been demonstrated for M x Sb electrodes (M = Li, Na) in Li/Na ion batteries. Despite a similar thermodynamic stability of the hexagonal and cubic polymorphs of Li3Sb, mostly cubic Li3Sb is observed at the end of discharge. In contrast, mostly the hexagonal Na3Sb polymorph is observed when cycling the Na/Sb, in agreement with its higher thermodynamic stability compared to the cubic polymorph. This polymorph selectivity is here investigated by means of simple thermodynamic and electrostatic considerations using first-principles Density Functional Theory (DFT) calculations. We show that the Na-based polymorphs are more ionic than their Li-based homologues, despite less ionic Na/Sb interactions. We establish a direct correlation between the relative compactness and stability of the M3Sb polymorphs to rationalize the preference of the hexagonal structure type for the most ionic compounds of the M3Sb series (M = Li, Na, K, Rb, Cs). The M−Sb interactions are further linked to the different electrochemical behaviours of the M x Sb electrodes through Madelung constant calculations. This method is based on the knowledge of only one given M x Sb composition and thus allows rationalizing the different intermediate compositions achieved through electrochemical cycling. To validate our method, we finally provide the first-principles computed phase stability diagrams which further reveal two new phases for both Li–Sb and Na–Sb systems.
The success of a brand extension depends largely on the similarity between the brand and its extension product. Recent psychological and neuroscientific evidence supports a dual-process model that distinguishes taxonomic feature-based similarity from thematic relation-based similarity. In addition to providing a parsimonious organizational framework for prior brand extension research, this dual-process model also provides novel predictions about the processing and evaluation of taxonomic brand extensions (e.g., Budweiser cola) and thematic brand extensions (e.g., Budweiser chips). Results indicate that taxonomic and thematic similarities independently contribute to branding professionals' and lay consumers' evaluations of real and hypothetical brand extensions (Studies 1A and 1B). Counter-intuitively, thematic brand extensions are processed more rapidly (Study 2), judged more novel, and evaluated more positively than taxonomic extensions (Study 3). When induced to consider the commonalities between the brand and the extension product, however, taxonomic extensions are judged more novel and evaluated more positively (Study 3). Implications for brand extension and marketing more generally are discussed.
Lithium-ion cells can unintentionally be exposed to temperatures outside manufacturers recommended limits without triggering a full thermal runaway event. The question addressed in this paper is: Are these cells still safe to use? In this study, externally applied compression has been employed to prevent lithium ion battery failure during such events. Commercially available cells with Nickel Cobalt Manganese (NCM) cathodes were exposed to temperatures at 80°C, 90°C and 100°C for 10h, and electrochemically characterised before and after heating. The electrode stack structures were also examined using x-ray computed tomography (CT), and post-mortems were conducted to examine the electrode stack structure and surface changes. The results show that compression reduces capacity loss by −0.07%, 4.95% and 13.10% respectively, measured immediately after the thermal testing. The uncompressed cells at 80°C showed no swelling, whilst 90°C and 100°C showed significant swelling. The X-ray CT showed that the uncompressed cell at 100°C suffered de-lamination at multiple locations after test, and precipitations were found on the electrode surface. The post-mortem results indicates the compressed cell at 100°C was kept tightly packed, and the electrode surface was uniform. The conclusion is that externally applied compression reduces delamination due to gas generation during high temperature excursions.
Chlorination roasting was used to extract lithium as lithium chloride from β-spodumene. The roasting was carried out in a fixed bed reactor using calcium chloride as chlorinating agent. The mineral was mixed with CaCl2 on a molar ratio of 1:2. Reaction temperature and time were investigated. The reactants and roasted materials were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD) and atomic absorption spectrophotometry (AAS). The mineral starts to react with CaCl2 at around 700°C. The optimal conditions of lithium extraction were found to be 900°C and 120min of chlorination roasting, under which it is attained a conversion degree of 90.2%. The characterization results indicate that the major phases present in the chlorinating roasting residue are CaAl2Si2O8, SiO2, and CaSiO3.