batterydata/paper-abstracts huggingface dataset:
The operating temperature of sodium-sulfur battery cells is above 300°C for use in molten liquid state electrodes. In order to achieve this high operating temperature condition in a battery module composed of multiple cells, a thermal management system, such as an electric heater and insulation, is essential. The efficiency of the module is directly dependent upon the temperature uniformity inside the module and the heat dissipation from the casing. In the present study, a new numerical model for the thermal analysis of a sodium-sulfur battery module is suggested. The equivalent thermal properties of the cell are evaluated by detailed thermal analysis on the cell. The heat generation of the cell is modeled considering the electrochemical reaction process and the variation of the resistance of the battery. Using these equivalent thermal models of the cell, a zero dimensional lumped thermal model for examining the effects of insulation and heater operation is developed. Finally, the three-dimensional temperature distribution inside the battery module is predicted by solving the thermal energy conservation equation numerically. The distribution of temperature and the thermal energy efficiency of the battery module for various design variables, such as cell arrangement and heater operations, are summarized.
Regenerative anion exchange membranes fuel cells (AEMFCs) have been widely considered as energy conversion and storage devices due to their low cost and high-energy storage capacity, especially when integrated with renewable resources. However, the oxygen electrode reactions have long been one of the primary limiting factors of regenerative AEMFCs due to their sluggish kinetics and resulting high overpotentials. To date, nanoparticles of platinum-group metals (PGMs) have been primary applied as catalysts because they are widely believed to simultaneously lower the thermodynamic and kinetic barriers of the oxygen reduction and evolution reactions (ORR and OER), which occur at a single electrode in unitized regenerative fuel cells (URFCs). However, the high-cost and scarcity of PGMs have recently shifted more researchers’ attention to nanostructured transition metal oxide-based non-PGM catalysts as alternatives for regenerative AEMFCs. Based on a theoretical analysis of the ORR/OER mechanism, the rate limiting steps of this reversible reaction pair has differing catalytic requirements, which make it challenging to develop effective bifunctional electrocatalysts with single active sites. Therefore, this review focuses on the development of ORR/OER dual active site nanostructured catalysts using transition metals or metal oxides that have been developed in recent years. Experimental evidence is critically collected from the literature to provide the perspectives of morphology, valence, electronic structure, energy band, etc. The second part of this review summarizes different methods to synthesize hybrid structures with advanced carbon materials, which compensates for the poor electrical conductivity that most pure transition metal oxides lack. Different mechanisms for improved activity at hetero-atomic interfaces are compared and analyzed. Furthermore, reversible ORR/OER electrocatalyst durability requirements are discussed for industrial implementation of regenerative AEMFCs, and promising pathways for future catalyst design are proposed.
A LiCoO2 thin film with a crystalline structure and free of the cubic phase is obtained by adopting a two-step treatment with a combination of bias substrate during RF sputtering and a post-annealing treatment at moderate temperature of 500°C or 400°C. All-solid-state Li/LiPON/LiCoO2 lithium batteries are fabricated using such crystalline bias LiCoO2 thin films. The crack-free surface of the cathode thin film and the nanosized LiCoO2 particles ensure an efficient electrochemical behavior and high performance of the battery. The rate capability and the influence of the voltage range on the rechargeable capacity delivered by the battery are investigated as well as cycling properties. A high capacity close to 50μAhcm−2 μm−1 is demonstrated at 10μA.cm−2 with an excellent rate capability since 86% of this value is recovered at 30C without any further damage of the cathode thin film. An excellent cycling behavior of the biased film is demonstrated since after a capacity decay of 12% over the first 100 cycles, the specific capacity practically does not decline over 800 additional cycles at 0.4C rate. These results compare very well with the best all-solid-state Li microbatteries built with LiCoO2 heat-treated at 700°C or more. It exemplifies the relevance of using biased LiCoO2 thin films heat-treated at moderate temperature (400°C-500°C).
The kinetics of the electrochemical lithium insertion reaction in crystalline V2O5 thin films in liquid electrolyte has been investigated using ac impedance spectroscopy. The experimental data are obtained for sputtered films characterized by a common morphology corresponding to an arrangement of V2O5 platelets perpendicular to the substrate (h 00 or 110 preferred orientation). The results are discussed as a function of the Li content for 0< x <1 in Li x V2O5, the film thickness in the range of 0.6–3.6μm and temperature 15–55°C. The moderate evolution of the chemical diffusion coefficient D vs. the lithium content is related with the specific structural response of these pure thin film materials which exhibit a single phase behavior. A comparison of the kinetic parameters for different thickness values allows to indicate the same Li diffusion rate whatever the film thickness and the diffusion pathway does not correspond to the thickness but to the length of the edge (≈1μm) of V2O5 platelets. For the first time, an experimental evaluation of the activation energy for Li diffusion in crystalline V2O5 is obtained. A value of 0.98eV is found for a diffusion phenomenon along the b direction. This work demonstrates the excellent capacity–rate performance as well as the efficient and homogeneous behavior of these oriented films can be explained by their specific microstructure.
Rice (Oryza sativa L.) is sensitive to chilling particularly at early stages of seedling establishment. Two closely related genes (OsLti6a, OsLti6b), which are induced by low temperature during seedling emergence were isolated from a cold tolerant temperate japonica rice cultivar. These genes are closely related to the Arabidopsis rare cold-inducible (RCI2) and barley low-temperature-inducible (BLT101) genes. Based on direct biochemical and indirect physiological evidence and similarity with a conserved protein domain in the Cluster of Orthologous Groups (COG) database (e.g., yeast PMP3), the rice genes belong to a class of low-molecular-weight hydrophobic proteins involved in maintaining the integrity of the plasma membrane during cold, dehydration and salt stress conditions. Both genes exhibit a genotype-specific expression signature characterized by early and late stress-inducible expression in tolerant and intolerant genotypes, respectively. The differences in temporal expression profiles are consistent with cultivar differences in cold-induced membrane leakiness and seedling vigor. The presence of CRT/DRE promoter cis-elements is consistent with the synchronized expression of OsLti6 genes with the C-repeat binding factor/drought responsive element-binding protein (CBF/DREB) transcriptional activator. The present results indicate that the Oslti6 genes are part of a battery of cold stress defense-related genes regulated by a common switch.
A commercial sheet of paper based on natural cellulose fibers acting as permeable membrane with thin film metal cathode (Cu) and anode (Al) layers in each face was used to produce paper batteries that could be interconnected in series and rechargeable using water as electrolyte. Their electrical characteristics and the set of electrochemical reactions that support the experimental behavior observed are described in this paper. A series of integrated batteries able to supply a voltage of about 3V and a current ranging from 0.7μA to 25μA in cells with sizes of 1.2cm×3.0cm for a relative humidity in the range of 50–65% were produced in a single sheet of paper, and successfully applied to control the ON/OFF gate state of paper transistors.
This paper reports the synthesis of Co2SnO4@C core–shell nanostructures through a simple glucose hydrothermal and subsequent carbonization approach. The as-synthesized Co2SnO4@C core–shell nanostructures have been applied as anode materials for lithium-ion batteries, which exhibit improved cyclic performance compared to pure Co2SnO4 nanocrystals. The carbon matrix has good volume buffering effect and high electronic conductivity, which may be responsible for the improved cyclic performance.
Core-shell LiFePO4@C composites were synthesized successfully from FePO4/C precursor using the polyvinyl alcohol (PVA) as the reducing agent, followed by a chemical vapor deposition (CVD) assisted solid-state reaction in the presence of Li2CO3. Some physical and chemical properties of the products were characterized by X-ray powder diffraction (XRD), Raman, SEM, TEM techniques. The effect of morphology and electrochemical properties of the composites were thoroughly investigated. XRD patterns showed that LiFePO4 has an order olivine structure with space group of Pnma. TEM micrographs exhibited that the LiFePO4 particles encapsulated with 3-nm thick carbon shells. The powders were homogeneous with grain size of about 0.8μm. Compared with those synthesized by traditional organic carbon source mixed method, LiFePO4@C composite synthesized by CVD method exhibited better discharge capacity at initial 155.4 and 135.8mAhg−1 at 0.1C and 1C rate, respectively. It is revealed that the carbon layer coated on the surface of LiFePO4 and the amorphous carbon wrapping and connecting the particles enhanced the electronic conductivity and rate performances of the cathode materials.
Sweat test is the standard for cystic fibrosis (CF) diagnosis. Conductivity is an alternative method not yet approved, in spite of its good correlation with chloride concentration. The aim was to assess the capacity of sweat conductivity to discriminate between CF and non-CF subjects. Automated measurements of conductivity and chloride concentration were carried out on the same sweat samples from subjects with clinical suspicion of CF. Sweat samples from 3834 subjects, median age 1.8 years (range 1 month–54 years) were analysed, and those with chloride titration >60 mmol/l were considered as CF patients (n=294). Conductivity median values in CF and non-CF subjects were 111 mmol/l (82–148) and 36 mmol/l (12–89), respectively. The Spearman correlation between chloride titration and conductivity was r=0.60 (P<0.001). The receiver operating characteristics (ROC) curve showed very high agreement between two methods. The best conductivity cut-off value to diagnose CF was ≥90 mmol/l (sensitivity 99.7%, specificity 100%, positive and negative predictive values of 100% and 99.97%, respectively, and kappa=0.998). Likewise, the best conductivity cut-off value to exclude CF was <75 mmol/l. The sweat conductivity method showed good correlation with chloride titration, and accurately discriminated between subjects with and without CF. In accordance with this, CF diagnosis might be confirmed for conductivity values ≥90 mmol/l and excluded for <75 mmol/l. Values between 75 and 89 mmol/l should correspond to an equivocal range. However, more studies are needed to confirm the role of conductivity in definitive CF diagnosis.
In this study, a core-shell nanostructure Fe2O3 coated grass-like Mn3O4 supported on graphene has been designed and fabricated via a facile and convenient hydrothermal method and thermal treatment routes. The Fe2O3 coated Mn3O4 nanorods with diameter of 35–40 nm are convolved by flexible graphene, which form a three-dimensional conductive network. As an anode for lithium-ion batteries, the as-prepared composite delivers an initial discharge/charge capacity of 1939.2/1393.5 mAh g−1 with a promising coulombic efficiency of 71.9% and a reversible specific capacity of 795.4 mA g−1 after 400 cycles at a high current density, which exhibits an upward trend in the capacity after long-term cycling as well. Both of the cross-linked structure and the synergistic effect are contributed to the enhance lithium-storage performance and dynamic characteristic, which reveals that the electrode holds a great potential as an anode material for rechargeable Li-ion batteries.
Nanostructured high surface area lithium cobalt oxide (LCO-CBL) cathode materials with uniform particle sizes are prepared by template assisted sol-gel synthesis using metal precursors and urea as chelating agent in cherry blossom leaf templates followed by calcination of the prepared material at 800°C for 12hrs. Structural and morphological characterization using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), field emission transmission electron microscopy (FE-TEM) and Raman spectroscopy of LCO-CBL shows the presence of rhombohedral (layered) structures quite similar to the pristine LCO, synthesized by simple sol-gel method. BET surface area measurements of the prepared cathode material revealed that the surface area increased about 79.7% for LCO-CBL, when compared to pristine LCO. Electrochemical characterization of the prepared LCO-CBL delivered an initial discharge capacity of the 166mAhg−1 with the capacity retention of 81% in comparison to the pristine LCO that exhibit initial discharge capacity of 127mAhg−1 and capacity retention of less than 72%.
The enhancement of the surface area and ordering of mesopores is a key parameter to increase the specific capacitance of electrochemical capacitors (ECs). These parameters can improve the electrolyte accessibility to the active material in order to improve its charge storage. In this work, magnetron sputtering at glancing angle (GLAD) is used in order to enhance the porosity of CrN for use as electrode material in ECs. The GLAD technique consists on tilting the substrate according to the deposition flux allowing the formation of well-separated columns due to a ballistic shadowing effect. Four different tilts of 0°, 45°, 60° and 75° were explored. While the CrN films deposited at 0° or 75° do not show any capacitive behaviour, a high areal capacitance is obtained at 45° or 60° (35.4 mF cm−2 at a current density of 1.2 mA cm−2 in 0.5 M H2SO4 electrolyte) with a good cycling stability over 10,000 cycles. On chip interdigitated micro-supercapacitors (MSCs) were assembled with a maximum energy density of 2 μWh.cm−2 (15.3 mWh.cm−3) at a power density of 20 μW cm−2 (0.15 W cm−3). The GLAD strategy can be generalised to other materials deposited by physical vapour deposition techniques, for highly porous electrodes, with improved electrochemical energy storage properties.
Two different Li-rich nickel–cobalt–manganese-oxide (Li-rich NCM) active materials with the same nominal composition 0.5Li2MnO3:0.5Li(Ni1/3Co1/3Mn1/3)O2 but different pristine nano structure have been analyzed structurally and electrochemically in different cycling states. For structural characterization, transmission electron microscopy (TEM) and high resolution synchrotron powder diffraction (S-XRD) experiments were conducted. The changes in structure with increasing cycle number are correlated with characteristic features in the corresponding electrochemical dQ/dV-profiles that were obtained by galvanostatically cycling the two different active materials. The presented data demonstrates that structural changes upon cycling, e.g. LiMnO2 and spinel formation, strongly depend on the degree oxygen is involved in the reversible charge compensation for delithiation/lithiation. According to our data, firstly a twin-like environment with nanometer dimensions is formed within the R-3m matrix during the initial cycle, which then gradually transforms into a spinel-like structure with increasing cycle number. As another result, we can show that Li2MnO3 to LiMnO2 transformation is not directly dependent in the irreversible oxygen loss in the first cycle but more importantly on transition metal migration. A model is presented explaining the dependency of LiMnO2 and spinel formation on the ability of Li-rich active materials to include oxygen in the charge compensation process.
The driving force for the metallic lithium formation in solid electrolytes, such as the cubic Li7La3Zr2O12 (c-LLZO), is still puzzling, considering the large band gap of c-LLZO and the preference of Li being ionic in oxides. In this paper, density functional theory (DFT) calculations were performed to investigate the ability of the pore surfaces to trap excess electrons, which is essential to Li nucleation tendency. Two interlayer materials were also studied, tetragonal LLZO (t-LLZO) and Li2PO2N (atomic layer deposited LiPON). It was found that excess electrons would be trapped, either around the La atoms on the surface of c-LLZO or dispersed on the surface of t-LLZO. It is also thermodynamically favorable for the excess electrons on La3+ to reduce Li+. In contrast, the excess electrons were located underneath the surface in Li2PO2N, making it hard to reduce Li+. Thus the surfaces in c-LLZO provide a possible electron pathway for metallic Li formation, and the t-LLZO interlayer observed at the Li/c-LLZO interface would not stop Li dendrites due to its similar Li nucleation tendency as c-LLZO. Furthermore, we propose that an interlayer of Li2PO2N at the Li/c-LLZO interface would be efficient and defect tolerant to suppress Li dendrite formation.
Over 75% of the medical devices used in India are imported. Often, they are costly and maladapted to low-resource settings. We have prepared case studies of six firms in Bangalore that could contribute to solving this problem. They have developed (or are developing) innovative health care products and therefore are pioneers in the Indian health care sector, better known for its reverse engineering skills. We have sought to understand what enablers and barriers they encountered.
In the present paper, we report a novel MnO2 cathode material doped with nano Ag4Bi2O5. The results of characteristic structure indicate that Ag4Bi2O5 is evenly distributed in the MnO2 material and affects the original structure of MnO2. The electrochemical performances of the doped electrode in the alkaline electrolyte are measured by galvanostatic method and cyclic voltammetry tests. Results show that the doped electrode has excellent electrochemical properties and its discharge voltage is 50–100mV higher than that of the traditional MnO2 electrode. The doped electrode can offer a discharge specific capacity of 481mAhg−1 at 120mAg−1. The cycling life of the doped electrode reaches up to 115 cycles, which is 3.4 times longer than that of electrolytic MnO2 electrode at a high current density of 1000mAg−1. The effect of doping Ag4Bi2O5 is much better than that of doping Bi2O3 or Ag2O independently, which indicates that Ag4Bi2O5 shows more superior electrochemical performance with the assistance of both Ag and Bi cations.
A zinc–lead dioxide rechargeable cell with an electrolyte composition of 1.5moldm−3 Zn(II), 0.5moldm−3 Na(I) and 0.3moldm−3 sulfuric acid is proposed and tested. The experimental results show that the open circuit potential of the zinc–lead dioxide cell is as high as 2.4V (20% higher than conventional lead-acid cells and 56% higher than recent copper–lead dioxide cells), while the average coulombic and energy efficiencies are 90% and 70%, respectively, over 90 cycles at 20mAcm−2. Furthermore, it is shown that the measured specific energy of the zinc–lead dioxide cell in a stack configuration is about 30% larger than that of a commercial valve regulated lead acid cell at the same operating conditions.
This research examines the extent to which visual cues influence a person’s decision to burglarize. Participants in this study (n = 65) viewed ten houses through an eye tracking device and were asked whether or not they thought each house was vulnerable to burglary. The eye tracking device recorded where a person looked and for how long they looked (in milliseconds). Our findings showed that windows and doors were two of the most important visual stimuli. Results from our follow-up questionnaire revealed that stimuli such as fencing, beware of pet signs, cars in driveways, and alarm systems are also considered. There are a number of implications for future research and policy.
The performance of full cells featuring high-voltage LiNi0.4Mn1.6O4 cathode and graphite anode with carbonate-based electrolytes, ethylene carbonate (EC) -dimethyl carbonate (DMC) with conventional LiPF6 and non-conventional Li[(C2F5)3PF3] (LiFAP) lithium salts with and without SEI-forming additives 1-fluoro ethylene carbonate (F1EC) and succinic anhydride (SA) is investigated. The results evidence the beneficial impact of EC-DMC-1M LiFAP electrolyte (LF30), with respect to EC-DMC-1M LiPF6 electrolyte (LP30), also in presence of 1.6% F1EC-2% SA additives, on charge retention over cycling and on self-discharge of full cells. After the 25 cycles of the charge capability test, the charge retention reached values up to 70% with LF30 and 87% with LF30 and additives, and fully charged cells with LF30-additives delivered 53% of the stored charge after one week in OCV.
This paper introduces the “discrete-time realization algorithm” (DRA) as a method to find a reduced-order, discrete-time realization of an infinite-order distributed-parameter system such as a transcendental impedance function. In contrast to other methods, the DRA is a bounded-time deterministic method that produces globally optimal reduced-order models. In the DRA we use the sample and hold framework along with the inverse discrete Fourier transform to closely approximate the discrete-time impulse response. Next, the Ho–Kalman algorithm is used to produce a state-space realization from this discrete-time impulse response. Two examples are presented to demonstrate the DRA using low-order rational-polynomial transfer functions, where the DRA solution can be compared to known solutions. A third example demonstrates the DRA with a transcendental impedance function model of lithium diffusion in the solid phase of a lithium-ion battery, showing that a third-order discrete-time model can closely approximate this infinite-order model behavior.
There is large hysteresis between charge and discharge curves in lithium-rich layer-structured cathode material, Li1.2Ni0.13Mn0.54Co0.13O2. The mechanism for hysteresis was examined by X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS) measurement as a first step in solving this issue. XRD measurements clarified that there was hysteresis in the lattice parameter between charge and discharge processes. XAFS spectra indicated that transition metals were oxidized and reduced in the same potential region during charge and discharge processes. Oxygen was oxidized at higher potential than transition metals during charge process; however, the former was reduced at lower potential than the latter during discharge process. Therefore, large hysteresis of potential between charge and discharge processes in Li1.2Ni0.13Mn0.54Co0.13O2 was mainly related to the reaction which is compensated with redox of oxygen.