batterydata/paper-abstracts huggingface dataset:
A new ionic liquid–polymer electrolyte was successfully tested in the planar amperometric solid-state sensor sensitive towards nitrogen dioxide. The electrolyte consists of 1-butyl-3-methylimidazolium hexafluorophosphate (BMIPF6) and poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) in the ratio 57:43mol.% and exhibits ionic conductivity 1.6×10−4 Scm−1 at 20°C, high electrochemical stability (over 4V on gold or glassy carbon) and thermal stability (over 230°C). The analyte, gaseous nitrogen dioxide in air, was determined using the electrochemical reduction at −900mV vs. Pt/air on gold minigrid indicating electrode with Pt/air as a reference electrode. The sensor response is linear in the NO2 concentration range 0.3–1.1ppm and is reproducible and long-term stable.
The mechanical integrity of the separator is critical to the reliable operation of a battery. Due to its minimal thickness, compression experiments with a single/a few layers of separator are difficult to perform. In this work, a capacitance based displacement set-up has been developed for the measurement of the through thickness direction (TTD) compression stress-strain behavior of the separator and the investigation of its interaction with the electrode. The experiments were performed for a stack of two layers of Celgard 2400 separator, NMC cathode, and separator/NMC cathode/separator stack in both dry and wet (i.e. submersed in dimethyl carbonate DMC) conditions. The experimental results reveal that the separator compression modulus can be significantly affected by the presence of DMC. The iso-stress based rule of mixtures was used to compute the compressive stress-strain curve for the stack from that of the separator and NMC layer. The computed curve agreed with the experimental curve reasonably well up to about 0.16 strain but deviated significantly to a softer response at higher strains. The results suggest that, in the stack, the TTD compressive deformation of the separator is influenced by the NMC cathode.
In recent years, issues concerning the future of multiethnic Sweden and particularly the situation in multiethnic suburbs have become a salient feature in Swedish politics. One important actor in recent years’ debates about the challenges facing multiethnic Sweden is the Swedish Liberal Party. Since the general election of 2002, the party has gained both publicity and electoral support by focusing on issues of integration of migrants and urban segregation in terms of assimilation and intensified demands targeted at the migrant others. In this article, the party’s developments in the early 2000s in the areas of integration and urban policy are analyzed within the framework of two general processes in contemporary politics: the politics of racialization and the medialization of politics. The party’s interventions in the area of integration and urban policy are built on an intimate as well as complex interplay between racialization and medialization. The agenda articulated by the party, further, has several similarities with the agenda of “authoritarian populist” movements throughout Europe.
Researchers have studied for decades workplace stress and burnout to identify their relationship to health and wellness. This research has focused on stress levels in people, as well as on environmental and personal factors that contribute to experiencing stress or burnout. In addition to the burnout measurement questionnaires (MBI-GS), Leiter and Maslach designed a model to evaluate the areas of work environment that relate to this construct (Areas of Worklife Scale-AWLS).
Thin-film electrodes were prepared by spraying aqueous suspensions of soaked leady oxide over both sides of lead sheets previously heated at 150°C. Uniform coatings of controlled thickness were obtained under optimum deposition conditions. The coatings, which retained their homogeneity after the electrochemical formation, were found to consist of small grains of β-PbO2 that tended to coalesce into micron-size units. The best electrochemical response was obtained from coatings of reduced thickness (20–40μm). Cells were found to retain a discharge capacity in excess of 100Ah/kg after extensive cycling. Also, electrodes exhibited excellent electrochemical performance at different discharge rates. However, if the coating was too thick, the paste was easily sulfated and the cell capacity faded after the first few cycles.
Thermal stability of cathode materials, including LiCoO2, LiNiO2, LiMn2O4, V2O5, V6O13, and Li x MnO2 in contact with poly(ethylene oxide) (PEO) based solid polymer electrolyte was systemically investigated by means of thermal analysis in combination with X-ray diffraction technique (XRD). The differential scanning calorimetry (DSC) analysis showed significant exothermic reaction of both LiNiO2 and LiCoO2 in contact with the polymer electrolyte. LiMn2O4 was less reactive compared with LiNiO2 and LiCoO2. V2O5, V6O13, and Li x MnO2 were also found less reactive, especially in their discharge states. The XRD results indicated that the thermal decomposition products of the cathode material were the low valance metal oxides, suggesting the exothermic reaction was an oxidation reaction of the polymer electrolyte with active material. The decomposition temperature is somehow dependent on the potential of the cathode active materials. Cyclic voltammetry reveals that PEO based solid polymer electrolyte is stable up to 5.0V versus Li/Li+ at a blocking electrode, whereas it decomposes at ca 3.8V when contacted with a carbon composite electrode.
Caterpillar-like spinel LiNi0.5Mn1.5O4 (LNMO) sub-micron structures with Fd3m space group were synthesised by polymer assisted sol-gel/electrospinning and post heat treatments in air atmosphere. The novel caterpillar structures were composed of 60–100nm sized well sintered and interconnected nano grains as observed by FESEM and TEM studies. The presence of Fd3m structure in the LNMO caterpillars were confirmed using X-Ray Diffraction and Raman spectroscopy studies. The Cyclic Voltammetry and Galvanostatic charge-discharge studies revealed the presence of substantial amount of Mn3+ in LNMO caterpillars. The LNMO caterpillar structures have exhibited high rate capability and excellent capacity retention (118mAh/g at 1C rate) after 100 cycles of charge discharge, when compared with P4332 LNMO sol heated powders (82mAh/g at 1C rate) synthesised in the absence of polymer. The EIS studies revealed low charge transfer resistances in LNMO caterpillars (4 times lower) in comparison to LNMO sol heated powders. The prepared LNMO caterpillar like structures with considerable Mn3+ concentration can be considered as a high performance cathode material for Lithium ion batteries.
A solution-chemistry approach was developed to prepare carbon-coated Li3V2(PO4)3 nanoparticles embedded in a micrometer-sized carbon matrix. The material was obtained by a facile one-pot synthesis involving a protic ionic liquid as a soft template and carbon source. To the best of our knowledge, the rate performance of electrodes based on this material is among the highest reported so far for Li3V2(PO4)3 due to the favorable nanoarchitecture combined with high electronic conductivity of the material. The capacity of the electrode only smoothly declines with increasing current density and reaches a value of about 100mAhg−1 at 100C when cycled between 3.0–4.3V vs. Li/Li+. Furthermore, excellent capacity retention of 70% after 10,000 cycles at 50C is demonstrated.
Flexible electronics with features of simple, low-cost, lightweight, recyclable, easily operable, and disposable are particularly desirable. Herein, a flexible fully-integrated self-powered system on paper was demonstrated by incorporating addressable paper circuit switch into potential-tunable foldable power paper. In which the electrode material as well as conducting interconnections, p-toluenesulfonic acid (p-TSA) doped polypyrrole embedded in-between the cellulose fibers (p-TSA-PPy/cellulose) were obtained by combining in-situ chemical oxidative polymerization with paper microfluidic technique. In such unique integrated configuration, the utilization of p-TSA-PPy/cellulose network not only dramatically enhanced the horizontal electrical conductivity, but also conquered the issue of vertical electroconductivity, allowing for the top-channel-bottom conductive interconnections. As a proof-of-concept, an all-paper microfluidic analytical platform that integrated paper-based electrochemiluminescence strategy and proposed power paper was constructed with comparable performance. This work greatly improves the understandings of all-paper-based self-powered systems, and presents the significant potential applications of paper-based flexible electronics.
The State of Charge (SOC) estimation is important since it has a crucial role in the operation of Electrical Vehicle (EV) power battery. This paper built an Equivalent Circuit Model (ECM) of the LiMn2O4 power battery, and vast characteristics experiments were undertaken to make the model identification and thus the battery SOC estimation was realized. The SOC estimation was based on the Strong Tracking Sigma Point Kalman Filter (STSPKF) algorithm. The comparison of experimental and simulated results indicates that the STSPKF algorithm performs well in estimating the battery SOC, which has the advantages of tracking the variables in real-time and adjusting the error covariance by taking the Strong Tracking Factor (STF) into account. The results also show that the STSPKF algorithm estimated the SOC more accurately than the Extended Kalman Filter (EKF) algorithm.
Novel light-driven and electro-driven polyethylene glycol (PEG)/two-dimensional MXene composite (PEG@MXene) with enhanced thermal conductivity and electrical conductivity as form-stable phase change material (FSPCM) is first obtained via the simple vacuum impregnation by employing MXene as the supporting skeleton as well as thermally conductive and electrically conductive filler and PEG as the phase change working substance. Fourier transform infrared spectroscopy (FT-IR) indicates that no chemical reaction occurred between PEG and MXene during adsorption process, but X-ray diffraction (XRD) results show the crystalline regions of PEG was decreased by the incorporation of MXene. The differential scanning calorimetry (DSC), polarizing microscope (POM), as well as XRD results demonstrate that the MXene nanosheets act as heterogeneous crystal nuclei and promote the crystallization of PEG. The melting and freezing latent heats of PEG@MXene are as high as 131.2 and 129.5 J/g, respectively, the relative enthalpy efficiency is 80.3%, and the thermal conductivity and electrical conductivity are 2.052 W/mK and 10.41 S/m, respectively. The obtained PEG@MXene has excellent light-to-thermal conversion, electro-to-thermal conversion and thermal energy storage performance. All these results demonstrate that the obtained PEG@MXene will have a great potential application for thermal energy storage.
This paper presents tests to characterize the mechanical resistance of the multilayers set which forms an all-solid-state lithium-ion micro battery. The system under investigation consists in five layers that were deposited successively onto a crystalline silicon substrate (100): Ti, TiOS, LiPON, aSi, Ti. The layer thicknesses are between 65 nm (amorphous silicon layer aSi) and 1400 nm (LiPON, TiOS). First, simple water immersion experiments allow internal stress to be put into evidence in the two external layers (aSi and Ti), basically a strong compressive stress in the aSi layer (at least −0.8 GPa). Afterwards, well-controlled 4-point bending tests lead to delamination of the weakest parts of the multilayer, which are the TiOS-LiPON and LiPON-aSi interfaces. The TiOS-LiPON interface is the weakest, with an adhesion energy around 2.5 J/m2. The TiOS layer exhibits a rather low cohesion energy, scarcely higher than 2.5 J/m2. The brittle character of LiPON clearly appears. By using samples of another kind (-Ti-TiOS-Ti on Si), local adhesion flaws are identified between the TiOS and underlying Ti layer. In our experiment, these local adhesion flaws lead to characteristic phenomena (formation of comet-shaped scales), which are explained in the framework of a simple mechanical model.
In this study, graphene/Co3O4 composites are prepared through a simple process under mild hydrothermal conditions. Sodium carbonate (Na2CO3) can produce many OH− and CO3 2− ions after dissolution and hydrolysis in a water–isopropanol system, thereby making it applicable as both depositing agent and reducing agent in the synthesis of graphene/Co2(OH)2CO3 composites. Remarkably, the galvanosta charge–discharge test shows that the specific capacitance value of the as-obtained composites reaches a high value of 443Fg−1 at a high current density of 5Ag−1, which is significantly improved in relation to Co3O4, and the capacitance retains 54% of capacitance at 60Ag−1. The fact that the specific capacitance remains 97.1% after 1000 continuous charge–discharge cycles at 10Ag−1 indicates that the as-prepared material has an excellent cycle life. The effect of the feeding ratios between Co3O4 and graphite oxide on the electrochemical performance has also been studied.
The effects of compressive force and the addition of conductive fillers on ultracapacitor electrode performance measurements were studied. We have shown that the force exerted by typical battery coin cell components is inadequate, resulting in erroneous measurements of electrode performance. We further demonstrated that with modest modifications, coin cell measurements can equal those of specialized test fixtures and of packaged cells.
The feasibility of an alkaline S2O4 2−/air-fuel cell was evaluated at room temperature, using a cell with an anion exchange membrane and a platinum oxygen reduction reaction catalyst. The tests performed were open circuit voltage analysis, linear sweep voltammetry, discharge analysis and electrochemical impedance spectroscopy (EIS) with registration of anode half-cell potential. With 0.85 M Na2S2O4 in 2 M KOH, the cell achieved a maximum power density of 2 mW cm−2, and the open circuit cell voltage was about 0.9 V. In a potentiostatic discharging at 0.2 V cell voltage, an energy efficiency of 12.3% was achieved at an energy density of 8.6 Wh L−1. The low power density was mainly due to the low reaction kinetics of dithionite oxidation at graphite electrodes. The low energy efficiency was mainly caused by a low cathode potential, which probably resulted from mixed potential formation and the low anode kinetics.
Caloric restriction (CR) has been shown to retard immunosenescence and to extend median and maximum life span in rodent species. Longitudinal effects of CR on the canine immune system are presented in this report. A group of 48 Labrador Retrievers, divided at weaning into weight- and sex-matched pairs, were maintained on a diet restriction protocol from age 8 weeks until death. Each restricted dog received 75% of the total food consumed by its control-fed pair mate. Immune parameters were monitored from 4 to 13 years. CR retarded age-related declines in both lymphoproliferative responses and absolute numbers of lymphocytes and the T, CD4, and CD8-cell subsets. In females, CR attenuated the age-related increase in T-cell percentages and marginally retarded the age-related increase in memory cell percentages. Age-related changes in B-cell percentages and numbers were augmented by CR. No direct effect of CR on phagocytic activity of PMN, antibody production or NK cell activity, was observed. Lower lymphoproliferative responses, lower numbers of lymphocytes, T, CD4 and CD8 cells, lower CD8 percentages and higher B-cell percentages were all found to be significantly associated with a decreased likelihood of survival in these dogs.
The primary systems framework has been used to relate behavioural performance across many different language activities to the status of core underpinning domain-general cognitive systems. This study provided the first quantitative investigation of this account at both behavioural and neural levels in a group of patients with chronic post-stroke aphasia. Principal components analysis was used to distil orthogonal measures of phonological and semantic processing, which were then related to reading performance and the underlying lesion distributions using voxel-based correlational methodology. Concrete word reading involved both a ventral semantic pathway, and inferior and anterior aspects of the dorsal phonological pathway. Abstract word reading overlapped with the ventral semantic pathway but also drew more extensively on the superior and posterior aspects of the dorsal phonological pathway. Nonword reading was related to phonological processing along the dorsal pathway and was also supported by a more superior set of regions previously associated with speech motor output. The use of continuous measures of behavioural performance and neural integrity allowed us to elucidate for the first time both the lesion and behavioural correlates for the semantic and phonological components of the primary systems hypothesis and to extend these by identifying the importance of an additional dorsal speech motor output system. These results provide a target for future neuroanatomically constrained computational models of reading.
The description of the transport mechanisms in operating Li ion battery cells is of key importance for a correct evaluation of their performance and for their optimization. In this work, we revise the Fickian approach for the description of the lithium transport in intercalation-type active materials. We adopt the Maxwell-Cattaneo-Vernotte (MCV) theory to capture the impact of lithium transport inertia on the electrochemical response of graphitic materials, taken here as an application example. We formalize this theory by means of an analytical mathematical expression which allows extracting the values of the lithium diffusion coefficient D MCV and the inertia characteristic time τ from potentiostatic intermittent titration technique (PITT) experiments. The implications of adopting the MCV theory in single particle models to calculate transient current response during the graphite lithiation are discussed (i) on the basis of the fitting of the calculations with in house PITT results and, (ii) by comparing the estimated diffusion coefficients with the ones resulting from the fitting using the classical Fickian approach.
A passive thermal management system is evaluated for high-power Li-ion packs under stressful or abusive conditions, and compared with a purely air-cooling mode under normal and abuse conditions. A compact and properly designed passive thermal management system utilizing phase change material (PCM) provides faster heat dissipation than active cooling during high pulse power discharges while preserving sufficiently uniform cell temperature to ensure the desirable cycle life for the pack. This study investigates how passive cooling with PCM contributes to preventing the propagation of thermal runaway in a single cell or adjacent cells due to a cell catastrophic failure. Its effectiveness is compared with that of active cooling by forced air flow or natural convection using the same compact module and pack configuration corresponding to the PCM matrix technology. The effects of nickel tabs and spacing between the cells were also studied.
Polyethylene separator is irradiated by gamma ray to investigate the effect on electrochemical and thermal properties of polyethylene separators. Applied irradiation dose was 50, 100, 150 and 200kGy. It is observed that the melt integrity temperature is increased as the higher dose of irradiation is applied. In case of non-irradiated PE separator, shut-down temperature is about 133°C and melt integrity temperature is 146°C. On the other hand, the separator with irradiation dose of 200kGy, shut-down temperature is about 136°C and melt integrity temperature is about 166°C. Thermal shrinkage test is performed at 150 and 120°C for 1h each. It is observed that the irradiated separator has better thermal shrinkage resistance than the non-irradiated one because of the cross-link of polyethylene formed by gamma ray irradiation. Therefore, it can be concluded that the cross-link of polyethylene formed by gamma ray irradiation is strongly effective against thermal shrinkage. The electrochemical test is performed at high rate using the irradiated separator and the non-irradiated one to investigate any trade-off. The high rate discharge characteristic of the irradiated separator is better than that of the non-irradiated one. FTIR spectral analysis of the irradiated and non-irradiated separators is performed and ionic conductivity was measured to understand the reason.
This review article summarizes recent and increasing efforts in the development of novel Li ion cell anode nanomaterials based on the coupling of C with Si. The rationale behind such efforts is based on the fact that the Si–C coupling realizes a favourable combination of the two materials properties, such as the high lithiation capacity of Si and the mechanical and conductive properties of C, making Si/C hybrid nanomaterials the ideal candidates for innovative and improved Li-ion anodes. Together with an overview of the methodologies proposed in the last decade for material preparation, a discussion on relationship between organization at the nanoscale of the hybrid Si/C systems and battery performances is given. An emerging indication is that the enhancement of the batteries efficiency in terms of mass capacity, energy density and cycling stability, resides in the ability to arrange Si/C bi-component nanostructures in pre-defined architectures. Starting from the results obtained so far, this paper aims to indicate some emerging directions and to inspire promising routes to optimize fabrication of Si/C nanomaterials and engineering of Li-ion anodes structures. The use of Si/C hybrid nanostructures could represents a viable and effective solution to the foreseen limits of present lithium ion technology.
The mining trade involves many complicated and interrelated variables—its complex environment, abundant machinery and a plethora of other contributors to accidents. In both developed and developing countries, mining accidents have caused many casualties. However, a universal risk assessment method for mining accidents is has not yet been implemented. Among risk assessment methods, the bow-tie has been used in different industry processes and systems and has proven effective. In this paper, the bow-tie model is utilized to investigate the relationship among mining accident risks, safety measures and possible consequences. The paper illustrates the hazards of mining accidents using US mine accident data. It also shows how the consequences of mine accidents are summarized by laws and regulations of different countries. This paper also introduces a series safety measures from Chinese safety standards and how the safety measures prevent and mitigate risks. At the end of the paper, a case of mine water inrush is applied using the bow-tie approach. The results show that the method is effective for analyzing mine safety.