batterydata/paper-abstracts huggingface dataset:
Silicon has a high theoretical capacity, still limits its application on Si-based anodes due to the problems of low electric conductivity, large volume change, continuous formation of unstable solid electrolyte interphase layer, and easy fracture during lithiation and delithiation process. Despite various carbon coating approaches are developed to fabricate carbon coated silicon core-shell and yolk-shell nanocomposites with improved electrochemical performance, the challenges including poor long-term cyclability, low Si mass ratio, and scalability remains. To overcome these challenges, we design an interfacial microporous carbon coating strategy on silicon nanoparticles to form homogeneous coaxial core-shell nanostructures. This synthesis sol-gel approach is simple, easy to scale up, and direct growth phenolic resins on the surface with uniform and controllable thickness. Additionally, the fabricated carbon layers form the microporous structures and phenolic resin frameworks, thus enabling the fast lithium ion transport and formation of stable solid electrolyte interphase film. By finely controlling the thickness of this phenolic resin-based carbon of 10nm, excellent protection of silicon nanoparticles as well as high electrochemical performance are achieved, delivering a high capacity of 1006mAhg−1 and Coulombic efficiency of >99.5% after 500 times at a current density of 500mAg−1.
This paper deals with the problem of estimating the state of charge (SOC) of lithium-ion batteries. Based on the analysis of the impedance spectra obtained by electrochemical impedance spectroscopy (EIS), a simplified battery impedance model is derived with the constant phase element (CPE). To interpret the impedance model, a fractional order calculus (FOC) method is introduced to model the CPE in the impedance model. A new identification method is proposed to identify the impedance model, considering both accuracy and simplicity. The fractional Kalman filter is introduced to estimate the SOC of the lithium-ion battery based on the impedance model. Finally, a battery test bench is established, and the proposed method is verified by a scaled down system on the urban dynamometer driving schedule (UDDS) drive cycle test.
Highly flexible and bendable free-standing polypyrrole-para (toluene sulfonic acid) (PPy-pTS) films were prepared using the electropolymerization method. The films are soft, lightweight, mechanically robust, and highly electrically conductive. The films display a cauliflower-like structure consisting of micron-scale spherical grains, which are related to dopant intercalation in the polymeric chains. The electrochemical behaviour of the free-standing films was examined as cathode against lithium counter electrode. Electrochemical tests demonstrated that the PPy-pTS film with 30min deposition time exhibited higher discharge capacity (85mAhg−1) beyond 80 cycles than the PPy-pTS films with 1h deposition time (76mAhg−1) and 2h deposition time (55mAhg−1) at 0.1mAcm−2 over a potential range of 2.5–4.3V. The free-standing films can be used as electrode materials to satisfy the new market demand for flexible and bendable polymer batteries.
Background Children undergoing heart transplantation who have preformed anti-human leucocyte antigen (HLA) panel reactive antibodies (PRA) or positive retrospective crossmatch (XM) may be at increased risk for rejection and graft failure. We assessed outcomes of transplant recipients with either positive PRA before transplant or positive retrospective XM. Methods A review of 148 heart transplant patients between 1990 and 2006 was undertaken, identifying transplants in patients with pre-transplant PRA > 1% and/or a positive XM. Demographic information and detailed post-transplant outcomes including episodes of rejection, infection, and graft failure were recorded. Results There were 11 PRA positive (PRA+) transplants, 135 PRA negative (PRA−) transplants, and no PRA data on 2. There were 14 XM+ transplants, 115 XM− transplants, and no XM data on 19. Kaplan-Meier graft survival was better in XM− than XM+ patients (p < 0.015), but not different between PRA+ and PRA− Groups. Timing of first rejection and number of rejection episodes were not different between XM+ and XM− Groups or between PRA+ and PRA− Groups. Infections were not different between PRA or XM Groups. Four patients were PRA+/XM− (all PRA, 1%–10%), 7 were PRA−/XM+, and 7 were PRA+/XM+ (6 of 7 PRA >10%). Conclusions Pediatric heart transplant patients whose retrospective XM is positive are at significantly increased risk for graft failure. Elevated pre-transplant PRA may not predict increased risk of graft failure, although markedly positive PRA (>10%) predicts a positive retrospective XM. Improved treatment for pediatric transplant patients with a positive retrospective XM is needed.
Currently, we are experiencing a technological shift, which is expected to change the way we program and interact with the world. Cloud computing and mobile computing are two prominent research areas that have already had such an impact. The Internet of Things (IoT), which is concerned with building a network of Internet-enabled devices to promote a smart environment, is another promising area of research. Numerous emerging computing paradigms related to those areas of research and/or their intersections have come into play. These include Mobile Cloud Computing (MCC), cloudlet computing, mobile clouds, mobile IoT computing, IoT cloud computing, fog computing, Mobile Edge Computing (MEC), edge computing, the Web of Things (WoT), the Semantic WoT (SWoT), the Wisdom WoT (W2T), opportunistic sensing, participatory sensing, mobile crowdsensing, and mobile crowdsourcing. Unfortunately, those paradigms suffer from the lack of standard definitions, and so we frequently encounter a single term referring to various paradigms or several terms referring to a single paradigm. Accordingly, this paper attempts to disambiguate those paradigms and explain how and where they fit in the above three areas of research and/or their intersections before it becomes a serious problem. They are tracked back to their inception as much as possible. This is in addition to discussing research directions in each area. The paper also introduces technologies related to the IoT such as ubiquitous and pervasive computing, the Internet of Nano Things (IoNT), and the Internet of Underwater Things (IoUT).
Zinc-ion batteries are considered as potential large-scale renewable energy storage devices due to low redox potential, low cost, large capacity, high electric conductivity, nontoxicity and easy processing of zinc metal. However, the development of cathode materials for zinc-ion batteries to date has been mainly limited to tunnel manganese oxides and Prussian blue analogues. Here we have firstly developed NASICON structured Na3V2(PO4)3 as cathode material for Zn-ion batteries. To compensate the low conductivity, graphene-like carbon wrapped Na3V2(PO4)3 nanoparticles are fabricated. With Na3V2(PO4)3/C as cathode, Zn metal as both counter and reference electrodes, and 0.5molL−1 Zn(CH3COO)2 solution as electrolyte, the aqueous Zn-ion battery delivers a reversible capacity of 97mAhg−1 at 0.5C and retains 74% capacity after 100 cycles. Meanwhile, the battery can be charged and discharged at high rate up to 10C. The cyclic voltammogram analysis shows that the Zn-ion storage in Na3V2(PO4)3 is a diffusion-controlled kinetic process. A mechanism of Zn ion occupancy variation during cycling is proposed. Our results provide an example for understanding and designing the intercalation process of divalent metal ions in NASICON structured cathode for new type rechargeable divalent metal ion batteries.
In this study, 1-methyl-1-butylpiperidinium bis(trifluoromethanesulfonyl)-imide (PP14TFSI)-sulfolane/lithium difluoro(oxalato)borate (LiDFOB) based electrolytes with inherent thermal stability and low flammability are investigated as promising alternatives of conventional LiPF6/carbonate electrolyte in high voltage Li/Li1.15(Ni0.36Mn0.64)0.85O2 cells at elevated temperatures. The safe and stable electrolyte candidates are selected by optimizing relative composition and represent high oxidative stability (higher than 5.2 V vs Li/Li+) above 55 °C. The Li/Li1.15(Ni0.36Mn0.64)0.85O2 cells with E60 electrolyte achieved 172.5 and 238.8 mAh g−1 after 50 cycles between 2.0 and 4.6 V at 0.5C at 55 and 70 °C. Moreover, the Li/Li1.15(Ni0.36Mn0.64)0.85O2 cell with E60 electrolyte obtains a superior discharge capacity of 97.9 mAh g−1 at high rate of 3C at 70 °C. At extremely high temperature of 85 °C, the cell with E60 electrolyte delivers 218.7 mAh g−1 after 50 cycles at 1C. The excellent cycling performance in high voltage Li/Li1.15(Ni0.36Mn0.64)0.85O2 cells at elevated temperatures is attributed to the intrinsic oxidative stability and the compact and stable cathode-electrolyte interface (CEI) film derived from E60 electrolyte. We believe it a promising candidate that can be safely used for high voltage Li-rich cells at elevated temperature.
In this work, highly porous Sn–C (HPSC) composite was synthesized by a simple carbothermal reduction method followed by a subsequent removal of template. The crystalline structure and morphology of the as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In the HPSC composite, sphere-like tin particles with a wide size distribution (100–300nm) were dispersed in porous carbon matrix and the Sn/C weight ratio is about 50/45. The electrochemical properties of the HPSC composite as an advanced anode material for high performance lithium-ion batteries were investigated by the galvanostatic method and cyclic voltammetry. The HPSC composite delivers a high specific capacity and good cycle performance with 535mAhg−1 even after 60 cycles. Moreover, the HPSC composite also exhibit excellent rate performance. The possible reasons why the composite has such an outstanding electrochemical performance are discussed also.
The lithium–oxygen (Li–O2) battery is one of the most promising technologies for energy storage due to its extremely high-energy density. However, the design still faces many challenges for practical use including the decomposition of cathodes, which are typically composed of carbon-based materials. In this study, a carbon-free and two-dimensional cathode structure based on silicene is first proposed for Li–O2 batteries using density functional theory calculations. In contrast to graphene, oxygen reduction reactions (ORR) and oxygen evolution reactions (OER) can occur on the pristine form of silicene without any defect sites. In addition, it was found that reactions on silicene strongly correlate with strong adsorptions of the ORR intermediates, which are caused not only by ionic bonding between the oxygen atoms in the ORR intermediates and silicene but also by the structural stabilization of silicene. Theoretical observations demonstrate the great potential of silicene as a carbon-free cathode structure for Li–O2 batteries and provide further insights for designing a new cathode material architecture based on two-dimensional structured materials.
The analysis of Li-ion secondary cells under outstanding conditions, as overcharge and high temperatures, is important to determine thermal abuse characteristics of electroactive materials and precise risk assessments on Li-ion cells. In this work, the thermal runaway behavior of LiCoO2 and LiMn2O4 cathode materials were compared at different state of charges (SOCs), including overcharge, by carrying out accelerating rate calorimetry (ARC) measurements using 18650 Li-ion cells. Onset temperatures of self-heating reactions and thermal runaway behavior were identified, and by using these onset points thermal mapping plots were made. We were able to identify non-self-heating, self-heating and thermal runaway regions as a function of state of charge and temperature. The cell using LiMn2O4 cathode material was found to be more thermally stable than the cell using LiCoO2. In parallel with the ARC measurements, the electrochemical behavior of the cells was monitored by measuring the OCV and internal resistance of the cells. The electrochemical behavior of the cells showed a slightly dependency on SOC.
Reliable and low cost energy storage technologies are required in order to store electrical energy on a large scale, as the power generated from intermittent renewable resources is continuously growing. Redox flow batteries are considered as a promising technology to lead a balanced solution for the future low emissions power sector challenges. The effect of temperature, charge/discharge current and state of charge on the performance of an iron-vanadium flow battery has been investigated in this study. VCl3 and FeCl2 in HCl(aq) electrolytes have been used for the anolyte and catholyte respectively, while graphite felt has been used for the electrodes. The results reveal an optimum operating temperature of ∼47°C and an optimum charging current of 50mAcm−2 when the battery is in a state of charge between 20 and 80%. The calculated voltage and coulombic efficiencies were estimated to be ∼85%. Under a mean linear flow velocity of ∼40cms−1, it has been found that the process is controlled by the sluggish kinetics of the V2+/V3+ half-reaction. The kinetic constant has been calculated equal to 0.8·10−5 cms−1 at 30°C and 4.5·10−5 cms−1 at 47°C, resulting in an activation energy of ∼110kJmol−1. A model based on the exchange current density values and the state of charge, has been used to calculate the charge transfer coefficient. The latter was found to decrease with respect to temperature from 0.63 at 30°C to 0.13 at 52°C.
Enthusiasm for the Circular Economy (CE) is widespread and overwhelming. However, confusion around its meaning and purpose still pervades the scientific debate. Our study has two objectives. The first one is to increase the theoretical clarity and the scientific relevance of this debate. An important step forward in this direction is the idea of economy’s circularity, which we introduce following a critical re-visitation of CE’s notion. The second objective is to study the environmental effects of circularity. Our notion of economy’s circularity is theoretically rooted in the materials-energy balance model, and points to the presence of circular matter and energy flows in the economy. A major strength of this definition is the conceptual separation of circularity (as an economy’s feature) from the strategies (e.g. recovery, remanufacturing, reusing…) for its implementation. On one hand, this separation prompts the construction of a coherent framework, which helps shed light on the entire debate. On the other hand, it paves the way towards a novel methodology for studying any type of circularity effect. Circularity effects are indeed the effects of circularity strategies. Since strategies are constantly evolving, this approach delivers an immediate result. Circularity effects are unavoidably ambiguous. With reference to the effects on the environment, we provide evidence for this ambiguity by accurately selecting and reviewing studies on various circularity strategies. In a policy perspective, our findings seriously challenge the idea of implementing circularity for the sake of circularity. Indeed, using circularity as an environmental policy may prove quite a daunting task.
This paper presents a model of innovation, knowledge brokering, that explains how some organizations are able to routinely innovate by recombining their past knowledge in new ways. While existing theories of organizational learning and innovation are useful, the links between them are crucial for understanding how existing knowledge becomes the raw materials from which individuals in organizations construct innovative solutions. This model develops these links by grounding processes of learning and innovation in the larger social context within which they occur. Using a microsociological perspective, this article draws together research spanning levels of analysis to explain innovation as the dissembling and reassembling of extant ideas, artifacts, and people. Previous research has suggested that firms spanning multiple domains may innovate by moving ideas from where they are known to where they are not, in the process creating new combinations of existing ideas. This paper more fully develops this process by linking the cognitive, social, and structural activities it comprises. Knowledge brokering involves exploiting the preconditions for innovation that reside within the larger social structure by bridging multiple domains, learning about the resources within those domains, linking that knowledge to new situations, and finally building new networks around the innovations that emerge from the process. This article also considers the origins of knowledge brokers as firms committed to this innovation strategy, the structural and cultural supports for the knowledge brokering process, and several obstacles to the process that these firms experience. Finally, I discuss the implications of this model for further research on innovation and learning, and the implications for other organizations seeking to establish their own capabilities for brokering knowledge.
The thermal energy storage (TES) system using phase change materials (PCMs) has been studied since past three decades. PCMs are widely used in heat storage applications due to their high storage density, as well as the wide range of melting and solidifying temperatures. Nevertheless, the main disadvantage of PCMs, especially salt hydrates, is their corrosive behavior with container materials. PCMs are normally encapsulated in containers, hence the compatibility of the container materials with PCM plays an important role. As such, this paper summarizes the investigations made on the corrosion behavior of PCM in various applications, besides suggesting ways to reduce (or rectify) the effect for long term successful energy storage. Moreover, PCM-storage material interaction in the latent heat TES system is important as the issue of corrosion affects the life of the container, as well as the performance of TES. The compatibility of the most commonly used PCMs with several major container materials was reviewed and it was revealed that stainless steel has emerged as the most compatible storage container material among others. On the other hand, aluminum was found to be corrosive when it is used with salt hydrates. Nonetheless, some contradictory articles are reported that several salt hydrates demonstrated compatibility with container materials. Corrosion causes thinning of cross sectional area of materials, making it brittle thus leading to an easy collapse. This situation is even more critical mainly in large scale concentrating solar thermal power plants. Hence, with the fact that there are currently large scale power plants employing TES under operation and under construction; issues pertaining to PCM-storage material compatibility should be properly and accurately addressed. Therefore, more research work is recommended in the area of finding new eutectics and less corrosive container material(s).
In the present study, we have reported a simple, facile and robust method for the controlled growth of polypyrrole microtubes (PPy MTs) on pencil graphite electrodes (PGE) via potentiostatic deposition without using any templates or structure-directing agents. The crucial role of the supporting electrolytes in dictating the formation of microtubules is analyzed and their nucleation – growth mechanism has been studied using the well-known Scharifker - Hills and Palomer – Pardove models. These microtubules modified pencil graphite electrodes exhibit a satisfactory supercapacitor behavior which has been demonstrated using voltammetric, charge-discharge and impedance studies. It has been observed that, the tubular-like geometry of PPy is more preferable for supercapacitor behavior than other morphology of PPy in the present context. Moreover, the influences of temperature on the specific capacitance and cycle stability have also been investigated. The effect of supporting electrolytes on the supercapacitive behavior of PPy MTs modified PGE have also been analyzed and a significant enhancement in the specific capacitance value with improved rate capability is observed in acidic medium than that of neutral medium. The profound increase in the magnitude of the specific capacitance of the bare pencil graphite electrodes upon modification with PPy MTs has been ascribed to its enhanced surface roughness, fractal dimension and porosity.
High-density Li4Ti5O12 powders comprising spherical particles are prepared by spray pyrolysis from a solution containing dimethylacetamide (drying control chemical additive) and citric acid and ethylene glycol (organic additives). The prepared powders have high discharge capacities and good cycle properties. The optimum concentration of dimethylacetamide is 0.5M. The addition of dimethylacetamide to the polymeric spray solutions containing citric acid and ethylene glycol helps in the effective control of the morphology of the Li4Ti5O12 powders. At a constant current density of 0.17mAg−1, the initial discharge capacities of the powders obtained from the spray solution with and without the organic additives are 171 and 167mAhg−1, respectively.
Breast cancer is identified as the highest cause of death in women suffering from cancer. Early diagnosis is the key to increase the survival of breast cancer victims. Molecular diagnosis using biomarkers have advanced much in the recent years. The cost involved in such diagnosis is not affordable for most of the population. The concept being investigated here is to realize a simple diagnosis system for screening cancer by way of a blood test utilizing a miRNA based biomarker with a complementary molecular beacon probe. A microfluidic platform was designed and attached with a fluorescence reader, which is portable and cost effective. Experiments were performed with 51 blood samples of which 30 were healthy and 21 were positive for breast cancer, collected against institutional human ethical clearance, IHEC 16/180–7–9-2016. miRNA 21 was chosen as the biomarker because it is overexpressed 4-fold in the serum of breast cancer patients. This work involved design of an experiment to prove the concept of miRNA over expression followed by detection of miRNA 21 using the microfluidic platform attached with a fluorescence reader and validation of the results using quantitative Real Time Polymerase Chain Reaction (qRT-PCR). The results obtained from the microfluidic device concurred with qRT-PCR results. The device is suitable for point-of-care application in a mass-screening programme. The study also has revealed that the stage of the cancer could be indicated by this test, which will be further useful for deciding a therapeutic regime.