batterydata/paper-abstracts huggingface dataset:
LiCoO2 is commercially available cathode electrode materials of lithium-ion batteries. In an attempt to improve the performance of lithium batteries with enhanced safety, LiCo1−x Mg x O2 was synthesized by the solid-state reaction method. The crystal structure was analyzed by X-ray diffraction and Rietveld refinement. LiCo1−x Mg x O2 give a single phase of a layered structure with the space group R-3m of hexagonal systems for x ≤0.11. A second phase of MgO was observed in LiCo1−x Mg x O2 for x ≥0.13. The calculated cation–anion distances and angles from the Rietveld refinement were changed with Mg content in samples. With the increase in Mg content in LiCo1−x Mg x O2, distances between CoO2 slabs were increased. The electrical conductivities of sintered samples were measured at room temperature by the Van der Pauw method. The electrical conductivities of LiCo1−x Mg x O2 increased with Mg content. On the basis of the Hall effect analysis, the increase in electrical conductivities with Mg content is believed due to the increased carrier concentrations, while the carrier mobility was almost invariant with the Mg content. The electrochemical performance of LiCo1−x Mg x O2 was evaluated by coin cell test.
In this work, spent Li-ion batteries were used to form cobalt and copper multilayers by electrodeposition. The effects of pH on the nucleation and growth mechanism, morphology and crystalline structure were studied. The instantaneous nucleation mechanism occurs at pH 2.7 and progresses at pH 5.4 for cobalt electrodeposition on platinum, vitreous carbon and aluminum. Copper can be electrodeposited on cobalt by an instantaneous mechanism at pH 2.7 and progressively at pH 5.4. Using scanning electron microscopy, we verified a more porous electrodeposit at pH 5.4 than at pH 2.7. X-ray diffractograms showed the peaks of Cu2O, CuO and the Co and Cu cubic centered face structures for both pH values at a charge density of 2.00 and 10.0Ccm−2. The electric circuit obtained by electrochemical impedance spectroscopy for Co–Cu multilayer growth at both pH 2.7 and 5.4 with a charge density equal to 2.0 and 10.0Ccm−2 on Al has the form R s(R p QL). The presence of the constant phase element (Q) is attributed to the irregularity of the Co–Cu multilayer electrodeposits, and the inductive element (L) is associated with cobalt dissolution in acidic solution.
Many efforts are being done to commercialize silicon (Si) as a high energy application anode for Li-ion batteries. However, still improvements are required at various levels from structural modification to fabrication process to commercialize Si as single anode material. In the present study, we report high improvement in the electrochemical performance of Si by shielding its surface with nano TiO2 particles. A layer of TiO2 nano particles is deposited on the surface of carbon coated nano Si by hydrothermal process to prevent the volume expansion during charge-discharge process. The sample is designated as Si/C-TiO2. The composite shows discharge capacity of 781 mAh g-1 after 200 cycles which was much higher than the capacity of pristine Si (23 mAh g-1) and carbon coated Si (Si/C) (215 mAh g-1) after 200 cycles. The Si/C-TiO2 composite has also shown higher capacity at all current rates from 100 mA g-1 to 2 A g-1 and a stable cycle life upto 200 cycles. The work also provides the morphological and structural studies of electrodes after charge-discharge cycles conducted by field emission scanning electron microscopy, X-ray diffraction and X-ray photon spectroscopy techniques.
Manganese dioxide nanofibers with length ranged from 0.1 to 1μm and a diameter of about 2–4nm were prepared by a chemical precipitation method. Composite electrodes for electrochemical supercapacitors were fabricated by impregnation of slurries of the manganese dioxide nanofibers and multiwalled carbon nanotubes (MWCNTs) into porous nickel foam current collectors. In the composite electrodes, MWCNT formed a secondary conductivity network within the nickel foam cells. Obtained composite electrodes, containing 0–20wt.% MWCNT with total mass loading of 40mgcm−2, showed a capacitive behavior in the 0.1–0.5M Na2SO4 solutions. The highest specific capacitance (SC) of 155Fg−1 was obtained at a scan rate of 2mVs−1 in the 0.5M Na2SO4 solutions. The SC increased with increasing MWCNT content in the composite materials and increasing Na2SO4 concentration in the solutions and decreased with increasing scan rate.
Tremella-like NiO@Co3O4@MnO2 particles of core-double-shelled structure were synthesized by a three-step hydrothermal route and thermal treatment. The hierarchical layered porous structure of the particles has a BET surface area of 179.2 m2 g−1. Galvanostatic cycling in 6.0 M KOH aqueous solution produced capacitance over an ideal cathode potential cycling range. At a high current density of 2 A g−1, NiO@Co3O4@MnO2 has a high specific capacitance of 792.5 F g−1 with > 90% capacity retention over 1000 cycles, and a high rate capability of 68.9% of its initial capacitance was also maintained over a 0.2–4 A g−1 current density increase. We conclude that NiO@Co3O4@MnO2 offers a promising high rate, high specific capacitance cathode material for alkaline supercapacitors, which owes both to its porous architecture and its synergistic mixed oxide core-shell-shell composition.
This paper presents a fuzzy CBR (case-based reasoning) technique for generating new product ideas from a product database for enhancing the functions of a given product (called the baseline product). In the database, a product is modeled by a 100-attribute vector, 87 of which are used to model the use-scenario and 13 are used to describe the manufacturing/recycling features. Based on the use-scenario attributes and their relative weights – determined by a fuzzy AHP technique, a fuzzy CBR retrieving mechanism is developed to retrieve product-ideas that tend to enhance the functions of the baseline product. Based on the manufacturing/recycling features, a fuzzy CBR mechanism is developed to screen the retrieved product ideas in order to obtain a higher ratio of valuable product ideas. Experiments indicate that the retrieving-and-filtering mechanism outperforms the prior retrieving-only mechanism in terms of generating a higher ratio of valuable product ideas.
Publisher Summary This chapter makes a comparison of rerefining and combustion routes in terms of saved petroleum equivalent tons. Both routes are used depending on whether financial support is available either for collection or for elimination. Upon examination of the methods of energy recovery, it appears that in terms of saved petrol equivalent tons, the advantages of the two routes of energy recovery, viz. regeneration and combustion, are not so clear. A closer analysis of the situation is made, taking into account the manufacturing energy cost of new oil in the combustion route and of the regenerated oil by the rerefining route; the comparison must be based on a complete statement of account. It is clear from an economic evaluation that the success of the described processes in the chapter is inextricably linked to the price of crude oil.
What do citizens think democracy is and what factors contribute to its meaning? Previous works on the public understanding of democracy have shown that, overall, citizens see democracy in “minimal” terms. However, advanced democracies are complex and encompass several elements other than elections and freedoms. This article uses the European Social Survey module “Europeans’ understandings and evaluations of democracy” and multilevel item response theory models to build a measure of the meaning of democracy in terms of multiple attributes and to account for individual- and country-level variation. The findings show that the meaning of democracy can be seen as a continuum, and that middle-aged educated men who are interested in politics, have extreme ideological positions, and are engaged in civic organizations include more elements in their idea of democracy, and that the cross-country variation in the meaning of democracy mostly depends on democratic performance.
Metal sulfides were considered as a promising anode material for sodium-ion batteries (SIBs). However, volume expansion during charging/discharging is an issue. One dimensional nanofibers are considered here to alleviate the change in stress of the anode's structure. Here we incorporated the nanofibers and WS2 nanosheets which used (DODA)3PW12O40 as the precursor. The precursor was prepared by an ion-exchange method, and then used to fabricate the anode material (denoted as DODA-WS2) via electrospinning. Use of surfactant dimethyldistearylammonium bromide (DODA·Br) disperses the WS2 nanosheets in the nanofibers. Carbonization and decomposition of DODA ligands provides porosity that accommodates volume expansion. The resulting structure of the anode material delivers high capacities of 363 and 318 mAh g−1 with 96% and 91% rate capacity retention after 400 cycles at 200 and 500 mA g−1, respectively. Also, improved rate capabilities (395 and 91 mAh g−1 at 50 and 10000 mA g−1, respectively) and good cycling stability (226.5 mAh g−1 after 800 cycles at 1000 mA g−1). These unique results are ascribed to the well-dispersed WS2 cross-linked nanofiber framework and its conductive network. This structure facilitates the transportation of electrons and Na+ and relieve the stress due to expansion. DODA-WS2 has a high potential for use as anode materials in SIBs.
The influence of Ce addition on the phase constitution, microstructure, hydrogen absorption/desorption properties and battery performances of newly developed rare earth (RE)-Mg-Ni hydrogen-absorbing superlattice alloys for negative electrode materials in Ni-metal hydride (MH) batteries were investigated. The partial substitution of RE (La and Nd) with Ce results in a higher discharge performance and a lower cycle life in the battery. The Ce addition greatly affects the phase constitution, which is mainly characterized by increased formation of the AB2 phase (A = RE or Mg and B = Ni or Al). The existence of the AB2 phase is found to accelerate alloy pulverization and oxidation when the alloys are used as negative electrode materials in Ni-MH model cells. The accelerated pulverization and oxidation are considered to be responsible for the observed higher discharge performance and lower cycle life in the batteries, respectively.
Lithium-ion batteries have been used in many applications owing to their high energy density and rechargeability. It is very important to monitor the internal physical parameters of the lithium-ion battery for safe and efficient usage, because this can help estimate the state of the battery, develop battery aging models, and schedule optimal operation of batteries. Parameter optimization methods using an accurate electrochemical battery model are much less expensive than direct parameter measurement methods, such as post-mortem methods. Thus, many model-based parameter optimization methods have been developed so far. However, most of these methods are random search methods that are based on heuristic rules, which leads to data-inefficient parameter identification. This means that they require many time-consuming battery model simulation runs to identify optimal parameters. Herein, a novel learning-based method is proposed for data-efficient parameter identification of lithium-ion batteries. A deep Bayesian neural network is used to efficiently identify optimal parameters. The simulations and experimental data validation show that the proposed method requires much fewer battery model simulation runs to identify optimal parameters than existing methods such as genetic algorithms, particle swarm optimization, and the Levenberg-Marquardt algorithm. The parameter estimation error of the proposed method is about 10 times lower than that of the second-best algorithm.
Background The brain-derived neurotrophic factor (BDNF) gene is involved in mechanisms of synaptic plasticity in the adult brain. It has been demonstrated that BDNF also plays a significant role in shaping externally induced human brain plasticity. Plasticity induced in the human motor cortex by intermittent theta-burst stimulation (iTBS) was impaired in individuals expressing the Val66Met polymorphism. Methods To explore whether this polymorphism is also important for other neuroplasticity-inducing tools in humans with modes of action differing from that of iTBS, namely, transcranial direct current (tDCS) and random noise stimulation (tRNS), we retrospectively analyzed the data of 64 subjects studied in our laboratory with regard to BDNF genotype. Results Fifteen subjects with the Val66Met allele, 46 subjects with the Val66Val allele, and 3 Met66Met carriers were identified. The response of the Val66Met allele carriers to stimulation differed in two protocols compared with the response of Val66Val individuals. For iTBS (15 subjects, 5 heterozygotes), plasticity could be only induced in the Val66Val allele carriers. However, for facilitatory tDCS (24 subjects, 10 heterozygotes), as well as for inhibitory tDCS, (19 subjects, 8 heterozygotes), carriers of the Val66Met allele displayed enhanced plasticity, whereas for transcranial random noise stimulation (29 subjects, 8 heterozygotes), the difference between groups was not so pronounced. Conclusions BDNF polymorphism has a definite impact on plasticity in humans, which might differ according to the mechanism of plasticity induction. This impact of BDNF on plasticity should be taken into account for future studies, as well as having wider ranging implications for the treatment of neuropsychiatric disorders with transcranial stimulation tools, as it may predetermine their efficacy for the treatment of disease and rehabilitation.
The drying process is a crucial step in electrode manufacture that may lead to spatial inhomogeneities in the distribution of the electrode components resulting in impaired cell performance. Binder migration during the drying process, and the ensuing poor binder coverage in certain regions of the electrode, can lead to capacity fade and mechanical failure (e.g. electrode delamination from the current collector). A mathematical model of electrode drying is presented which tracks the evolution of the binder distribution, and is applicable in the relatively high drying rates encountered in industrial electrode manufacture. The model predicts that constant low drying rates lead to a favourable homogeneous binder profiles, whereas constant high drying rates are unfavourable and result in accumulation of binder near the evaporation surface and depletion near the current collector. These results show strong qualitative agreement with experimental observations and provide a cogent explanation for why fast drying conditions result in poorly performing electrodes. Finally, a scheme is detailed for optimisation of a time-varying drying procedure that allows for short drying times whilst simultaneously ensuring a close to homogeneous binder distribution throughout the electrode.
Established safety of lithium ion batteries is key for the vast diversity of applications. The influence of aging on the thermal stability of individual cell components and complete cells is of particular interest. Commercial 18650-type lithium ion batteries based on LiNi0.5Co0.2Mn0.3O2/C are investigated after cycling at different temperatures. The variations in the electrochemical performance are mainly attributed to aging effects on the anode side considering the formation of an effective solid-electrolyte interphase (SEI) during cycling at 45 °C and a thick decomposition layer on the anode surface at 20 °C. The thermal stability of the anodes is investigated including the analysis of the evolving gases which confirmed the severe degradation of the electrolyte and active material during cycling at 20 °C. In addition, the presence of metallic lithium deposits could strongly affect the thermal stability. Thermal safety tests using quasi-adiabatic conditions show variations in the cells response to elevated temperatures according to the state-of-charge, i.e. a reduced reactivity in the discharged state. Furthermore, it is revealed that the onset of exothermic reactions correlates with the thermal stability of the SEI, while the thermal runaway is mainly attributed to the decomposition of the cathode and the subsequent reactions with the electrolyte.
In this work, an overview of the interconnections between membrane technology and renewable energy sources (biomass, salinity gradient power, wind, solar) is given. Regarding biomass, membrane processes such as membrane reactors and bio-reactors, membrane contactors, membrane distillation in the logic of process intensification strategy may be opportunely integrated in the production processes of green fuels. Their advantages such as reduction of the separation load and stage number, improved yields and selectivities compared to conventional processes imply low direct energy consumption, lower footprint area occupied by the processes plants. Moreover, the possibility of integration these advanced membrane processes with other traditional membrane operations such as microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), reverse osmosis (RO), pervaporation (PV) allows the reduction of indirect energy consumption through the recycling and reuse of raw materials and secondary materials minimizing the formation of wastes. Both Pressure Retarded Osmosis (PRO) and Reversed Electro Dialysis (RED), the only two technologies for which salinity gradient power-based demonstration projects are running, use membranes. In this article, key points and challenges to be faced for both PRO and RED are reported. On the other side, membrane desalination plants, are more often considered excellent locations to install wind and solar power generators. Most advanced research in the field is focused on solar assisted membrane distillation (MD). In the logic of fully "sustainable desalination", highly innovative technologies such as Microbial desalination cells (MDCs) could be integrated as pre-treatment stage in membrane desalination plants in remote, arid regions.
Measurements obtained during real-world activity by wearable motion sensors may contribute more naturalistic accounts of clinically meaningful changes in impairment, activity, and participation during neurologic rehabilitation, but obstacles persist. Here we review the basics of wearable sensors, the use of existing systems for neurological and rehabilitation applications and their limitations, and strategies for future use.
Previous research on the diffusion of solar PV in Africa has mainly focused on solar home systems (SHS) in individual countries and thus overlooked developments in other PV market segments that have recently emerged. In contrast this paper adopts a regional perspective by reviewing developments in supportive policies, donor programs and diffusion status in all PV market segments in Kenya, Tanzania and Uganda, as well as identifying the key factors put forward in the literature to explain differences in the diffusion of SHS in these three countries. The paper finds two emerging trends: (i) a movement from donor and government-based support to market-driven diffusion of solar PV; and (ii) a transition from small-scale, off-grid systems towards mini-grids and large-scale, grid-connected solar power plants. The paper points out three generic factors that have contributed to encouraging SHS diffusion in all three countries: (i) the decline in world market prices for PV modules; (ii) the prolonged support from international donors; and (iii) conducive framework conditions provided by national governments. The paper also identifies five key factors that have been elaborated in the literature to explain the higher level of SHS diffusion in Kenya compared to Tanzania and Uganda: (i) a growing middle-class; (ii) geographical conditions; (iii) local sub-component suppliers; (iv) local champions; and (v) business culture. Finally, the paper discusses the lack of attention in the literature given to analysing the amount, nature and timing of donor and government support across countries, processes of learning and upgrading in local PV industries and the interaction between the different explanatory factors.
Highly soluble iodide/triiodide (I−/I3−) couples are one of the most promising redox-active species for high-energy-density electrochemical energy storage applications. However, to ensure high reversibility, only two-thirds of the iodide capacity is accessed and one-third of the iodide ions act as a complexing agent to stabilize the iodine (I2), forming I3− (I2I−). Here, we exploit bromide ions (Br−) as a complexing agent to stabilize the iodine, forming iodine–bromide ions (I2Br−), which frees up iodide ions and increases the capacity. Applying this strategy, we demonstrate a novel zinc/iodine–bromide battery to achieve an energy density of 101 W h Lposolyte+negolyte−1 (or 202 W h Lposolyte−1), which is the highest energy density achieved for aqueous flow batteries to date. This strategy can be further generalized to nonaqueous iodide-based batteries (i.e. lithium/polyiodide battery), offering new opportunities to improve high-energy iodide-based energy storage technologies.
Water electrolysis is a core technology in the conversion of renewable energy to hydrogen, which is useful for energy storage and transportation. Alkaline water electrolysis (AWE) is one of the most suitable technologies because of its low cost and applicability to large-scale production of hydrogen; however, the AWE system exhibits electrode degradation under fluctuating electricity from renewable energy such as solar and wind energies. In this study, we demonstrate the use of a hybrid cobalt nanosheet (Co-ns), comprising brucite-type cobalt hydroxide modified with the tripodal ligand tris(hydroxymethyl)aminomethane, to form a highly stable self-repairing catalyst layer on a nickel anode under cycled potential. The Co-ns is functionalized by organic modification as a self-repairing catalyst with high catalytic activity, high dispersibility in an alkaline electrolyte, and protection of the nickel anode from corrosion. The Co-ns supplied from the alkaline electrolyte forms a catalyst layer via the anodic reaction on the surface of the nickel anode. This catalyst layer is detached under cycled potential simulating the fluctuating electricity of renewable energy; however, it is repaired by the constant current electrolysis simulating the steady state operation of AWE. The reaction between the Co-ns and nickel anode strengthens the connection between the catalyst layer and substrate. Furthermore, the Co-ns is less influential to the activity of a commercial cathode, indicating applicability to the conventional AWE system without changing the manifold structure. Consequently, the specially designed Co-ns catalyst shows great potential as a novel self-repairing function in an AWE system, which will enable stable operation under fluctuating electricity from renewable energy.
For this study, Fe-substituted Li2MnO3 (Li1+x(Fe0.25Mn0.75)1-xO2, 0 < x < 1/3) was prepared using coprecipitation–calcination. The change in the cation distribution was examined after charge–discharge using a monoclinic Li2MnO3 unit cell (C2/m). At the initial Li-extraction, Fe ion moved to the tetrahedral 8j site. At the end of charging, transition metals moved from 4g and 2b sites in (Mn, Fe)Li layer to 2c and 4h sites in the Li-layer via 4i and 8j sites. The cation random distribution was maintained after the end of discharging. The stability of layered rock-salt phase after cycle testing depended on the mode of charging; although the positive electrode decomposed to a mixture of layered rock-salt and spinel phases by typical galvanostatic charging, the positive electrode remained a single phase with a layered rock-salt structure by application of stepwise charging. Careful control of the charging mode at the initial cycle is important for Fe-substituted Li2MnO3 positive electrode material.