batterydata/paper-abstracts huggingface dataset:
Monodispersed and uniform cubic LiMn2O4 with side length of 5.0 μm denoted as CB and spherical LiMn2O4 with different diameters (2.0, 3.5, 8.0 μm) denoted as SS, MS, BS respectively are prepared through a controllable precipitation of precursors MnCO3 and a followed melt-impregnation process. Studies show that the electrochemical performance of LiMn2O4 samples with spherical morphology are better than those of the cubic one. Moreover, the spherical LiMn2O4 (MS) with middle size (3.5 μm in diameter) has the best electrochemical performance among three spherical samples instead of the smallest spherical LiMn2O4. The determined apparent lithium ion diffusion coefficients of prepared samples decrease in the order of MS > SS > BS > CB and their values are in the range of 10−9.5–10−11.5 cm2 s−1 and 10−8.0–10−10.5 cm2 s−1 from PITT and CITT respectively. This trend matched well with the electrochemical performances of the four cathode materials. This observation can be addressed to the fact that the middle size spherical particles balance the contradictory of diffusion length in solid phase and particle agglomeration, which lead to perfect contacts with the conductive additive, considerable apparent Li-ion diffusion rate and the best performance of MS LiMn2O4.
Re-investigation of Li insertion into the layers of Li1+x V1−y M y S2 (M=Cr, Ni and y =0 and 0.1, x ≤0.8) reveals that the transformation of Li from octahedral to tetrahedral sites in Li1+x VS2 leads to a 1.0V stabilization V(III)/V(II) plateau at 0.1C rate. Substitution of 10mol% Ni for V to form Li1+x V0.9Ni0.1S2 increases the voltage on Li insertion by 0.1–0.2V compared to nominal LiVS2, but it leads to an overall decrease in the capacity. An irreversible capacity loss on the initial charge/discharge cycle is the result of formation of an SEI layer at and below 1V versus lithium. 10mol% substitution of Cr for V (i.e. Li1+x V0.9Cr0.1S2) has no effect on the voltage, but it increases the capacity fade as the discharge/charge cycles progress.
Water has a fatal influence on the performance of lithium ion batteries. In this work, Lithium hexafluoro phosphate(LiPF6)-ethylene carbonate (EC)/diethyl carbonate (DEC) and lithium bis(oxalato)borate (LiBOB)-tetramethylene sulfone (SL)/DEC are taken as examples to investigate the influences of water concentration for electrochemical window, acidity, impedance and cycling performance for lithium ion batteries by adjusting water concentrations in the electrolytes. Results show that LiBOB-based electrolyte has better water tolerance compared with LiPF6-based system, due to the formation of LiBOB·xH2O compounds by consuming the additive trace water. Besides, inductively coupled plasma test result shows that Mn ion dissolution in LiPF6 systems is extremely severe, which is mainly caused by the corrosive reaction between LiMn2O4 and by-product HF acid. And we believe that Mn ion dissolution and the following deposition should be responsible for failure work of LiPF6-based cells. But for LiBOB-based cells, stable SEI layers and good electrochemical performances have been obtained, benefitting from the synergistic effect between LiBOB salt and SL solvent. And the presence of high-resistance B(C2O4) (OH) and LiB(C2O4) (OH)2 products on surface of graphite electrode is the main reason for a small number of capacity fading.
ZnCo2O4 was synthesized through the rheological phase reaction method using zinc acetate dehydrate, cobalt (II) acetate tetrahydrate, and citric acid as raw materials. The precursors were heat-treated in a muffle furnace at 400°C or 500°C, respectively. The samples were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The electrochemical properties of the samples were investigated. The results show that ZnCo2O4 nanoparticles were synthesized successfully. The particles took on irregular quasi-spherical shapes, and the sizes of the particles were less than 100nm. The electrochemical properties showed that the ZnCo2O4 synthesized at 400°C featured better reversible capacity than that of ZnCo2O4 synthesized at 500°C, and its specific capacity was 801mAhg−1 after 100 cycles at a constant current of 100mAhg−1 in the voltage range of 0.01–3V. Hence, the ZnCo2O4 synthesized by this method could be a promising anode material for lithium ion battery application.
Sulfonated graphene (SG) prepared by anchoring the organic sulfonic acid on the surface of the graphene nanosheets was used as the unique dopant for the in situ chemical oxidative polymerization of pyrrole for the well-defined flake-shaped sulfonated graphene/polypyrrole (SG/PPy) composites. The structures of these composites with the different feeding ratio of SG had been characterized by TEM, SEM, FTIR, Raman and XRD techniques. The SG sheets were homogeneously coated on both surfaces with PPy. Themogravimetric analysis revealed a significantly enhanced thermal stability. The SG/PPy composite S-4 (50wt% SG) with the well-defined flake-shaped morphology exhibited the highest electrical conductivity of 50Scm−1, while the SG/PPy composite S-2 (30wt% SG) possessed the highest specific capacitance (261.0Fg−1) at the charge–discharge current density of 1Ag−1 in 1.0M H2SO4 electrolyte. About 87% of its original specific capacitance could be remained after 1000 cycles. The excellent capacitance behavior also was found in electrochemical impedance spectroscopy. It makes the SG/PPy composite a promising electrode material for high performance supercapacitors.
In order to satisfy the requirement of high energy density and long cyclability for lithium-ion batteries, Fe2+ self-doped hierarchical flower-like mesoporous Fe2O3 nanosheets with a high specific surface area of 120.57 m2 g−1 are prepared through ultrafast microwave assisted systhesis and post calcination. The obtained Fe2O3 exhibits a superior electrochemical performance on lithium storage (2000 mA h g-1 at 400 mA g-1 up to 300 cycles and 1750 mA h g−1 at 1 A g-1 even up to 1000 cycles) and excellent cycling stability, which are likely to be associated with the specific structure and increased electronic conductivity contributed from Fe2+ defects. These findings not only enormously improve the electrochemical property of Fe2O3 anode, but offer a new perspective for designing of distinctive nanomaterials for various energy devices.
Pines constitute a major tree crop, providing an array of products to several industrial sectors, but still holding significant new and unrealized potential worldwide. Among non-wood pine products resin is one of the best known and most exploited. Resin is a complex mixture of terpenes produced by specialized cells dedicated to tree defense. Terpenes from resin find various applications in industry, including chemicals, pharmaceuticals, agrochemicals, food additives, and bioenergy. More recent potential uses of resin products are biodegradable batteries and as components in the manufacturing of green plastics. Besides resin, other non-wood products from pines include needles, cones and bark, which can be used for landscaping, as well as plant cultivation substrates, biofuels and bioherbicides. Additional applications include medium-density fiberboard ingredients, metal biosorption composites, and production of nanofibrillated cellulose. The availability of industrial quantities of renewable non-wood biomass is a topic of significance due to the depletion of fossil-based raw materials and the respective environmental impact of their use. In this review, current and emerging applications of non-wood pine products are discussed, highlighting the importance of fully exploiting these forest resources in a sustainable fashion for maximum revenue generation.
Preliminary evidence suggests that the enteric microbiota may play a role in the expression of neurological symptoms in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Overlapping symptoms with the acute presentation of d-lactic acidosis has prompted the use of antibiotic treatment to target the overgrowth of species within the Streptococcus genus found in commensal enteric microbiota as a possible treatment for neurological symptoms in ME/CFS.
Manganese oxide/carbon (MnO x /C) composite powders showing high performance as lithium-ion battery anode are synthesized by a facile co-precipitation process followed by thermal calcination between 400 °C and 700 °C in N2, where the as-deposited MnO2 is reduced progressively to Mn3O4 and then to MnO. The role of conductive additive is investigated by adopting two carbon (C) materials of different dimensionalities, including carbon black (CB) nanoparticles and micron-sized graphitic flakes (GFs). For MnO x /CB composite, the cycling stability is remarkably enhanced with increasing calcination temperature, and this is due to increasing content of MnO, which exhibits superior redox reversibility than the oxides having higher Mn valences. Attempt to achieve single-phase MnO at higher temperature (700 °C), nevertheless, leads to deteriorated cycle performance because of the formation of large oxide particles having poor contact with CB. The use of the two-dimensional GFs creates the “balls-on-plate” oxide-C configuration. This configuration facilitates MnO formation at lower temperature and simultaneously enables retention of good oxide-C contact, leading to significantly enhanced cycling stability and rate performance. The MnO x /GF composites obtained by calcination at 500–600 °C show specific capacities of 550–600 mAh g−1-(oxide + C) with no capacity fading after 150 cycles.
A photo-rechargeable supercapacitor (photo-supercapacitor, or PSC) is studied using a N3-dye adsorbed TiO2 photoelectrode and PProDOT-Et2 poly(3,3-diethyl-3,4-dihydro-2H-thieno-[3,4-b][1,4]dioxepine) polymer films as supercapacitor materials for electron storage. The PSC device, comprising a dye-sensitized solar cell (DSSC) and a supercapacitor (SC), can store the photo-to-electric energy. The PProDOT-Et2 films are potentiostatically electropolymerized to form thick films (ca. 0.5mm) with a specific capacitance of ca. 6.5Fcm−2. A symmetrical (p/p) supercapacitor, with PProDOT-Et2 coated on both electrodes, is also characterized before fabricating the three-electrode PSC. The PSC is tested under light illumination of 100mWcm−2, and attaining a photocharged voltage of 0.75V and a discharged energy density of 21.3μWhcm−2.
Solid acid polymer electrolytes (SAPE) were synthesised using polyvinyl alcohol, potassium iodide and sulphuric acid in different molar ratios by solution cast technique. The temperature dependent nature of electrical conductivity and the impedance of the polymer electrolytes were determined along with the associated activation energy. The electrical conductivity at room temperature was found to be strongly depended on the amorphous nature of the polymers and H2SO4 concentration. The ac (100Hz to 10MHz) and dc conductivities of the polymer electrolytes with different H2SO4 concentrations were analyzed. A maximum dc conductivity of 1.05×10−3 Scm−1 has been achieved at ambient temperature for electrolytes containing 5M H2SO4. The frequency and temperature dependent dielectric and electrical modulus properties of the SAPE were studied. The charge transport in the present polymer electrolyte was obtained using Wagner's polarization technique, which demonstrated the charge transport to be mainly due to ions. Using these solid acid polymer electrolytes novel Zn/SAPE/MnO2 solid state batteries were fabricated and their discharge capacity was calculated. An open circuit voltage of 1.758V was obtained for 5M H2SO4 based Zn/SAPE/MnO2 battery.
The exposure of cells to ultraviolet B radiation (UVB) can induce the production of reactive oxygen species (ROS) which damage cellular components. Free radical scavengers and antioxidants can interfere with the production of ROS. We studied cytotoxicity, intracellular ROS levels, lipid peroxidation, antioxidant status and oxidative DNA damage in cultured human skin dermal fibroblast adult cells (HDFa) exposed to UVB in the presence of sesamol, a natural phenolic compound. The levels of cytotoxicity, intracellular ROS, lipid peroxidation, oxidative DNA damage and apoptotic morphological changes were significantly increased in UVB irradiated HDFa cells. We also observed that the activities of enzymatic antioxidants (superoxide dismutase, catalase and glutathione peroxidase) and the levels of non-enzymatic antioxidant status (GSH) were significantly decreased in UVB irradiated cells. On the other hand, sesamol pretreatment significantly decreased cytotoxicity, intracellular ROS, lipid peroxidation, oxidative DNA damage and apoptotic morphological changes in sesamol-pretreated and UVB-irradiated HDFa cells. We have also observed increased enzymatic and non-enzymatic antioxidants status in sesamol plus UVB-irradiated cells. Among the different doses tested, 80 μM of sesamol shows maximum protection for UVB-induced oxidative damage. In conclusion, UVB-induced ROS formation, cell fatality, lipid peroxidation, antioxidant depletion and oxidative DNA damage in HDFa cells is inhibited by sesamol, which, probably through its ROS scavenging activity.
With an objective of understanding the differences in the capacity retention behavior and cycle life of cathode consisting transition metal phosphate, Cr0.5Nb1.5(PO4)3, active material and the binder polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE), the role of these binders have been analyzed. An electrochemical analysis of the active material mixed with the binders PVDF or PTFE reveals that the PTFE cell experiences an additional discharge capacity of 93 mA h g−1 during the discharge cycle compared to the PVDF cell. The results of X-ray photoelectron spectroscopy studies of the PTFE mixed cathode reveals nearly the same intensity of F (1s) spectra for before and after discharge cycles suggests that the fluorine atom is not decomposed but permits high utilization of the reactant to be achieved in the cathode during discharge/charge cycles. A remarkable improvement in cell performance in terms of capacity and cycle life for PTFE suggests that the binder PTFE should be an attractive candidate in lithium batteries than that of PVDF.
Plug-in hybrid electric vehicle (PHEV) is one of the most promising products to solve the problem about air pollution and energy crisis. Considering the characteristics of urban bus route, maybe a fixed-control-parameter control strategy for PHEV cannot perfectly match the complicated variation of driving conditions, and as a result the ideal vehicle fuel economy would not be obtained. Therefore, it is of great significance to develop an adaptive real-time optimal energy management strategy for PHEV by taking the segment characteristics of driving cycles into consideration. In this study, a novel energy management strategy for Plug-in hybrid electric bus (PHEB) is proposed, which optimizes the equivalent factor (EF) of each segment in the driving cycle. The proposed strategy includes an offline part and an online part. In the offline part, the driving cycles are divided into segments according to the actual positions of bus stops, the EF of each segment is optimized by linear weight particle swarm optimization algorithm with different initial states of charge (SOC). The optimization results of EF are then converted into a 2-dimensional look up table, which can be used to make real-time adjustments to online control strategy. In the online part, the optimal instantaneous energy distribution is obtained in this hybrid powertrain. Finally, the proposed strategy is verified with simulation and hardware in the loop tests, and three kinds of commonly used control strategies are adopted for comparison. Results show when the initial SOC is 90%, the fuel economy with the proposed strategy can be improved by 15.93% compared with that of baseline strategy, and when the initial SOC is 60%, this value is 16.02%. The proposed strategy may provide theoretical support for control optimization of PHEV.
Manganese oxalate is a novel conversion anode material for lithium ion batteries, but its low conductivity limits its application. To overcome this drawback, we report MnC2O4 microtubes prepared via a rapid assembly process in a T-type microchannel reactor. The X-ray diffraction (XRD) patterns and scanning electron microscope (SEM) images confirm that MnC2O4·2H2O microtubes are monoclinic α phase with a C2/c space group; MnC2O4 microtubes have a Pmna orthorhombic structure. As-synthesized MnC2O4 microtubes exhibit a high reversible capacity of 925 mAh⋅g−1 after 100 cycles at 1 A ⋅g−1. Even at an ultra-high current density of 5 A⋅ g−1, the anode MnC2O4 microtubes deliver a constant discharge capacity of 721 mAh⋅g−1 with a capacity retention of 97% on the 100th cycle. The improved performance can be attributed to the unique microtube structure composed of MnC2O4 nanoparticles, leading to faster electrode kinetics.
LiNiPO4–LiCoPO4 solid solutions were investigated as potential cathodes for use in Li-ion batteries. Cyclic voltammetry and discharge curves reveal that the discharge capacity of the LiNiPO4–LiCoPO4 solid solutions is associated entirely with the Co3+/Co2+ redox couple at a potential of 4.7–4.8V. The effect of Ni is to reduce the length of the 4.7–4.8V plateau.
The existing plants for the recovery of exhausted alkaline zinc manganese dioxide batteries adopt an initial heat treatment and then a grinding. The last operation intermixtures the components of the batteries and consequently the successive recovery process proves to be rather complicate and needs a large scale plant. An initial dismantling and separation of the anodic, cathodic and packing components allow a successively easier recovery process and a small scale plant. This possibility has been assumed in this work and a simple recovery process has been proposed for the anodic material, consisting of an initial leaching step to separate and recover the unconverted metallic zinc and a successive step of cathodic deposition to recover the converted ionic zinc. A highly efficient zinc recovery has been obtained at the cathodic deposition step by adopting a heat treatment of the anodic material before its leaching process.
This study presents an original control algorithm for a hybrid energy system with a renewable energy source, namely, a polymer electrolyte membrane fuel cell (PEMFC) and a photovoltaic (PV) array. A single storage device, i.e., a supercapacitor (ultracapacitor) module, is in the proposed structure. The main weak point of fuel cells (FCs) is slow dynamics because the power slope is limited to prevent fuel starvation problems, improve performance and increase lifetime. The very fast power response and high specific power of a supercapacitor complements the slower power output of the main source to produce the compatibility and performance characteristics needed in a load. The energy in the system is balanced by d.c.-bus energy regulation (or indirect voltage regulation). A supercapacitor module functions by supplying energy to regulate the d.c.-bus energy. The fuel cell, as a slow dynamic source in this system, supplies energy to the supercapacitor module in order to keep it charged. The photovoltaic array assists the fuel cell during daytime. To verify the proposed principle, a hardware system is realized with analog circuits for the fuel cell, solar cell and supercapacitor current control loops, and with numerical calculation (dSPACE) for the energy control loops. Experimental results with small-scale devices, namely, a PEMFC (1200W, 46A) manufactured by the Ballard Power System Company, a photovoltaic array (800W, 31A) manufactured by the Ekarat Solar Company and a supercapacitor module (100F, 32V) manufactured by the Maxwell Technologies Company, illustrate the excellent energy-management scheme during load cycles.
Constructing hierarchical porous structures on the current collectors is an attractive strategy for improving the rate performance of the Li ion battery electrodes. However, preparing hierarchical porous structures normally requires hard or soft templates to create hollows or pores in different sizes. Rigorous preparation conditions are needed to control the size (especially nanosize) and size distribution of the pores obtained by conventional methods. Herein, we describe a template-free two-step synthesis process to prepare hierarchical porous Co3O4 films on Ni foam substrates. In this synthesis process, free-standing mesoporous precursor flakes are deposited on Ni foams by an electrochemical method. Subsequently, the meosporous precursor flake arrays are calcined to obtain hierarchical porous Co3O4 films. More strikingly, the size of the mesopores in the flakes can be adjusted by altering the calcination temperature. The structure and morphology of the samples are characterized by scanning electron microscopy, transmission electron microscopy and Brunauer–Emmett–Teller measurements. The relationship of the in-flake-pore size and the calcinations temperature is proposed here. Electrochemical tests have revealed that the hierarchical porous Co3O4 films demonstrate excellent rate performances (650mAhg−1 at 30C) as Li ion battery anodes due to the hierarchical porous structure, which endows fast ion transmission.
Oxygen reduction electrocatalysts based on the monoethanolmine complexes {[CoEtm]2(μ-Etm)4Ni(NO3)2} and {[CoEtm]2(μ-Etm)4Ni(NO3)2} + activated carbon AG-3 have been obtained by high-temperature synthesis. The nature of active centers on the synthesized electrocatalysts was described. Using potentiostatic and cyclic potentiodynamic voltammetry, the kinetic characteristics of catalysts in the oxygen electroreduction reaction were determined. Thermal decomposition of the thermally unstable complexes was described and character of the active centers formed was discussed. The optimal synthesis temperature of electrocatalysts is 600 °C in an inert atmosphere. The calculated exchange current densities for the oxygen electroreduction reaction at the catalysts in 1 M KOH at 20 °C was j0 = 1.01 × 10−3 A g−1–3.3 × 10−3 A g−1. The Tafel slopes of stationary polarization curves are 0.054–0.063 V for b1 and 0.106–0.125 V for b2. The prepared electrocatalysts can be recommended only for electrochemical systems with alkaline electrolyte.
Radio networks (RN) are distributed systems (ad hoc networks) consisting in n ≥ 2 radio stations. Assuming the number n unknown, two distinct models of RN without collision detection (no-CD) are addressed: the model with weak no-CD RN and the one with strong no-CD RN. We design and analyze two distributed leader election protocols, each one running in each of the above two (no-CD RN) models, respectively. Both randomized protocols are shown to elect a leader within O ( log ( n ) ) expected time, with no station being awake for more than O ( log log ( n ) ) time slots (such algorithms are said to be energy-efficient). Therefore, a new class of efficient algorithms is set up that match the Ω ( log ( n ) ) time lower-bound established by Kushilevitz and Mansour [E. Kushilevitz, Y. Mansour, An Ω ( D log ( N / D ) ) lower-bound for broadcast in radio networks, SIAM J. Comp. 27 (1998) 702–712).].