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Mechanistic Origin of the High Performance of Yolk@Shell Bi2S3@N-Doped Carbon Nanowire Electrodes
摘要： High-performance lithium-ion batteries are commonly built with the heterogeneous composite electrodes that combine multiple active components for serving various electrochemical and structural functions. Engineering these heterogeneous composite electrodes toward drastically improved battery performance is hinged on a fundamental understanding of the mechanisms of multiple active components and their synergy or tradeoff effects. Herein, we report a rational design, fabrication, and understanding of yolk@shell Bi2S3@N-doped mesoporous carbon (C) composite anode, consisting of a Bi2S3 nanowire (NW) core within a hollow space surrounded by a thin shell of N-doped mesoporous C. This composite anode exhibits desirable rate performance and long cycle stability (700 cycles, 501 mAhg-1 at 1.0 Ag-1, 85% capacity retention). By in-situ transmission electron microscopy (TEM), X-ray diffraction, and NMR experiments and computational modeling, we elucidate the dominant mechanisms of the phase transformation, structural evolution, and lithiation kinetics of the Bi2S3@C NW anode. Our combined in-situ TEM experiments and finite-element simulations reveal that the hollow space between the Bi2S3-NW core and carbon shell can effectively accommodate the lithiation-induced expansion of Bi2S3-NWs without cracking C shells. This work demonstrates an effective strategy of engineering the yolk@shell-architectured anodes and also sheds light onto harnessing the complex multistep reactions in metal sulfides to enable high-performance lithium-ion batteries.
关键词： multiple computational modeling,lithiation mechanism,in-situ experiments,yolk@shell composite anode,lithium-ion battery
更新于2025-09-23 15:21:01
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In situ forming of ternary metal fluoride thin films with excellent Li storage performance by pulsed laser deposition
摘要： In the field of lithium ion battery, conversion-based metal fluoride cathodes are attractive for their excellent theoretical capacity and high voltage. However, the utilization of binary metal fluorides is severely hindered by irreversibility and large voltage hysteresis. The introduction of ternary metal fluorides, like AgCuF3 and CuxFe1-xF2, brings hope to address these shortcomings. To better understand the basic mechanism of conversion reaction in ternary metal fluoride cathodes, the Cu–Fe–F (CFF) thin films were successfully grown in situ by pulsed laser deposition in this work. The physico-chemical properties and electrochemical performance were discussed. Such a CFF solid solution phase presented great cycle stability (82% capacity remains after 100 cycles at current density of 285 mA g?1) and higher energy efficiency (71.8%), which can be attributed to the reversible structural rearrangement after the delithiation process disclosed by ex situ XPS, high-resolution TEM, and selected-area electron diffraction.
关键词： Thin film,Ternary metal fluoride,Lithium ion battery,Pulsed laser deposition
更新于2025-09-23 15:19:57
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Surfactant assisted sonochemical synthesis of zinc tungstate nanoparticles: Anode for Li-ion battery and photocatalytic activities
摘要： Herein, we report a simple, economic and low-cost surfactant assisted sonochemical synthesis of ZnWO4 nanoparticles. The structural and morphological features of nanoparticles were characterized by X-ray di?raction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV-visible spectroscopy, photoluminescence (PL) spectroscopy and transmission electron microscopy. ZnWO4 had been proven to be one of the most promising electrodes for energy storage and found that the discharge capacity was of 173 mA h g?1 even after 20 cycles at 0.1C rate. In addition to this, good photocatalytic degradation e?ciency (98.6% in 120 minutes) was also achieved through Rhodamine B as a model of pollutant system.
关键词： photocatalytic activities,Rhodamine B,sonochemical synthesis,Li-ion battery,ZnWO4 nanoparticles
更新于2025-09-23 15:19:57
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Topochemical Path in High Lithiation of MoS <sub/>2</sub>
摘要： Lithiation of MoS2/RGO (reduced graphite oxide) electrodes repeatedly reached experimental capacities larger than 1000 mA·g–1, corresponding to at least 6 lithium equivalents per gram of MoS2. At our best knowledge, a convincing explanation is still missing in literature. In most cases, phase separation into Li2S and elemental Mo was assumed to occur. However, this can only explain capacities up to 669 mA·g–1, corresponding to an exchange of four Li. Formation of LiMo alloys could resolve the problem but the Li/Mo system does not contain any binary phases. If signs for Li2S formation were found, indeed experimental capacities were below 700 mAh·g–1. Here we present a topochemical mechanism, which sustains multiple charge/discharge cycles at 1000 mAh·g–1, corresponding to an exchange of at least 6 Li per formula unit MoS2. This topochemical reaction route prevents decomposition into binary phases and thus avoids segregation of the components of MoS2. Throughout the whole lithiation/delithiation process, distinct layers of Mo are preserved but extended or shrunk by slight movements and reshuffling of sulfur and lithium atoms. On addition of 6 Li per formula unit to MoS2, all central sulfur atoms are hosted in mutual Mo–S layers such that formal S2– and Mo2– anions appear coordinated by lithium cations. Indeed, similar structures are known in the field of Zintl phases. Our first-principles crystal structure prediction study describes this topological path through conversion reactions during the lithiation/delithiation processes. All optimized phases along the topological path exhibit a distinct Mo layering giving rise to a series of dominant scattering into pseudo 001 reflections perpendicular to these Mo planes. The mechanism we present here explains why such high capacities can be reached reversibly for MoS2/RGO nano composites.
关键词： topological path,Crystal structure prediction,Total energy calculations,MoS2,Li-Mo-S ternary phases,Li-ion battery,Lithium
更新于2025-09-23 15:19:57
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Properties of Nitrogen/Silicon Doped Vertically Oriented Graphene Produced by ICP CVD Roll-to-Roll Technology
摘要： Simultaneous mass production of high quality vertically oriented graphene nanostructures and doping them by using an inductively coupled plasma chemical vapor deposition (ICP CVD) is a technological problem because little is understood about their growth mechanism over enlarged surfaces. We introduce a new method that combines the ICP CVD with roll-to-roll technology to enable the in-situ preparation of vertically oriented graphene by using propane as a precursor gas and nitrogen or silicon as dopants. This new technology enables preparation of vertically oriented graphene with distinct morphology and composition on a moving copper foil substrate at a lower cost. The technological parameters such as deposition time (1–30 min), gas partial pressure, composition of the gas mixture (propane, argon, nitrogen or silane), heating treatment (1–60 min) and temperature (350–500 ?C) were varied to reveal the nanostructure growth, the evolution of its morphology and heteroatom’s intercalation by nitrogen or silicon. Unique nanostructures were examined by FE-SEM microscopy, Raman spectroscopy and energy dispersive X-Ray scattering techniques. The undoped and nitrogen- or silicon-doped nanostructures can be prepared with the full area coverage of the copper substrate on industrially manufactured surface defects. Longer deposition time (30 min, 450 ?C) causes carbon amorphization and an increased fraction of sp3-hybridized carbon, leading to enlargement of vertically oriented carbonaceous nanostructures and growth of pillars.
关键词： vertically oriented graphene (VOG),Li-ion battery,roll-to-roll technology,inductively coupled plasma chemical vapor deposition (ICP CVD),supercapacitor
更新于2025-09-19 17:15:36
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Graphite lithiation and capacity fade monitoring of lithium ion batteries using optical fibers
摘要： Increasing the e?ciency and safety of battery management systems may require internal monitoring of lithium ion batteries. In this work, we present an analysis of the interaction between ?ber-optic evanescent wave sensors (FOEWS) and graphite particles within a lithium ion battery over multiple cycles. Through slow charging and long rest periods, the FOEWS signal has shown sensitivity to lithium concentration at the surface of graphite particles by demonstrating a response to the slow di?usion of lithium ions within graphite particles during rest periods (i.e. relaxation of the electrode). The slope of the FOEWS signal during a full charge is found to exhibit three distinct peaks that occur within lithiated graphite's stage transitions zones IV, III and II. Deviation from the observed three peak trend correlates with signi?cant battery capacity fade and thus indicate the sensors ability to detect capacity fade in real-time. During experiments, signi?cant deviations in the slope during charging occurred at about ~5% SOC and minor disturbances to the slope were observed at ~80% SOC, which supports limiting the depth of charge and discharge to avoid accelerated capacity fade. These results deepen our understanding of the FOEWS's interaction with lithium ion batteries and supports the development of algorithms that optimize the control and monitoring of graphite lithiation with the aim of achieving safer operation as well as maximizing capacity and battery life.
关键词： Optical ?ber sensor,Lithium ion battery,State of charge,Graphite,Capacity fade,Signal analysis
更新于2025-09-19 17:13:59
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[IEEE 2018 2nd IEEE International Conference on Power Electronics, Intelligent Control and Energy Systems (ICPEICES) - Delhi, India (2018.10.22-2018.10.24)] 2018 2nd IEEE International Conference on Power Electronics, Intelligent Control and Energy Systems (ICPEICES) - Design & Implementation of Solar Fed Intensity Controlled Streetlight
摘要： SPV based LED Streetlight has advantages over other conventional lighting systems as no power conversion is needed. LED work on DC and energy optimization is possible by controlling the duty cycle of the LED driver. The components of Solar Fed LED Street lighting system are SPV array, MPPT, dc-dc converter and battery unit. In this paper, the intensity of solar fed Street light is controlled from traffic hours to non-traffic hours which results in saving the electricity consumption. A hybrid street light model is also designed and developed. The simulation studies are performed in Matlab-Simulink environment.
关键词： DC-DC converter,AC/DC module,PV array,LED array,MPPT,Li-ion battery
更新于2025-09-16 10:30:52
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Economic and environmental assessment of reusing electric vehicle lithium-ion batteries for load leveling in the residential, industrial and photovoltaic power plants sectors
摘要： Reaching 70–80% of primary capacity, lithium-ion batteries must be replaced in electric vehicles. However, they could be reused in other applications such as energy storage stations. In this paper, an economic evaluation of reusage of lithium-ion packs for load leveling in the residential, industrial and photovoltaic power plants sectors have been investigated from subscriber and government aspects. Several repurposed electric vehicle battery packs have been taking into account for different tariffs and scenarios. It is found that utilization of battery can reduce electricity bill for residential consumers by 14.25% based on the current electricity market and 39.75% if the fine of the peak time consumption is tripled. However, the current subsidy rate in the electricity tariffs is the main barrier in terms of the payback period for homeowners. Moreover, it is found that decrease in the battery prices by 2035 as the only factor will not justify usage of repurposed battery in residential sector, furthermore, tariffs must also be regulated. Sensitivity analysis declared that a 20% reduction in the price of battery in residential sector, affects the internal rate of return by 164%. Meanwhile, increasing in the on-peak tariff can fluctuate it by 44%. Reusing electric vehicle batteries could be more profitable in the industrial sector due to the realistic tariff. In addition to the operation cost, government saving is analyzed from the initial cost aspect. Results illustrated that utilization of repurposed battery packs can reduce construction costs of new on-peak thermal power plants by 72.5% and 82% in the residential and industrial sectors, respectively. Finally, the effect of using repurposed lithium-ion battery packs on the emission rates of greenhouse gases and other air pollutants are surveyed. The reused batteries can be employed to achieve sustainable development.
关键词： Load leveling,Secondary use,Lithium-ion battery,Environmental analysis,Electric vehicle,Economic analysis
更新于2025-09-16 10:30:52
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Improving the Reliability of Photovoltaic and Wind Power Storage Systems Using Least Squares Support Vector Machine Optimized by Improved Chicken Swarm Algorithm
摘要： In photovoltaic and wind power storage systems, the reliability of the battery directly affects the overall reliability of the energy storage system. Failed batteries can seriously affect the stable operation of energy storage systems. This paper aims to improve the reliability of the storage systems by accurately predicting battery life and identifying failing batteries in time. The current prediction models mainly use artificial neural networks, Gaussian process regression and hybrid models. Although these models can achieve high prediction accuracy, the computational cost is high due to model complexity. Least squares support vector machine (LSSVM) is a computationally efficient alternative. Hence, this study combines the improved chicken swarm optimization algorithm (ICSO) and LSSVM into a hybrid ICSO-LSSVM model for the reliability of photovoltaic and wind power storage systems. The following are the contributions of this work. First, the optimal penalty parameter and kernel width are determined. Second, the chicken swarm optimization algorithm (CSO) is improved by introducing chaotic search behavior in the hen and an adaptive learning factor in the chicks. The performance of the ICSO algorithm is shown to be better than CSO using standard test problems. Third, the prediction accuracy of the three models is compared. For NMC1 battery, the predicted relative error of ICSO-LSSVM is 0.94%; for NMC2 battery, the relative error of ICSO-LSSVM is 1%. These findings show that the proposed model is suitable for predicting the failure of batteries in energy storage systems, which can improve preventive and predictive maintenance of such systems.
关键词： chaotic search,least squares support vector machine,chicken swarm optimization algorithm,storage system,sustainable lithium-ion battery
更新于2025-09-16 10:30:52
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In-depth study of annealed porous silicon: Understand the morphological properties effect on negative LiB electrode performance
摘要： Silicon (Si) used as negative electrode in a Li-ion battery (LIB) is highly attractive for its high energy density, safe cycling, and nontoxicity. However its alloying mechanism with Li induces material pulverization, which leads to a rapid capacity fade. In this work, annealing post treatment was used in order to tune the morphological properties of porous silicon. Playing on annealing temperature, the morphological modification induces electrochemical behavior changes in LIB. The porosification is an interesting way to accommodate the volume expansion occurring during the alloying process. Increase of the annealing temperature leads to porous Si pores and walls reorganization, which has a positive impact on battery performance likely due to a higher wettability of the Si electrode with electrolyte. 700 °C appeared to be the optimized annealing temperature.
关键词： Negative electrode,Morphological properties,Li-ion battery,Annealing,Silicon,Electrochemical behavior,Porous silicon
更新于2025-09-16 10:30:52