batterydata/paper-abstracts huggingface dataset:
A high-efficiency (14.3%) solar cell using silicon nanopencils (SiNPs) was achieved by controlling surface carrier recombination and nanostructure morphology. Radial p-n junction nanopencils have several advantageous features that derive from their asymmetric structure, which enables excellent broad-band absorption and light trapping. The surface carrier recombination problem caused by plasma etching was solved using a chemical polish etching (CPE) method. The control of CPE treatment and SiNP morphology can reduce the surface recombination and increases the effective junction area. And bulk recombination was minimized by reducing the wafer thickness. These techniques have the potential to achieve low-cost and high-efficiency photovoltaic cells.
The first bottom-up electrochemical approach for the preparation of viologen (1,1′-didodecyl-4,4′-bipyridinium salt) nano/microsized wires and tubes are described. This approach involves film formation of the viologen using the micellar disruption method followed by transformation of the film into the nano/microstructures using a potential sweep technique. The hexagonal cross-section of the wires and tubes has a 400nm–30μm width and >1mm length. The formation mechanism of the nano/microstructures was discussed on the basis of the X-ray photoelectron spectroscopic analyses, FT-IR spectra, scanning electron microscopic observation, UV–vis spectra, and cyclic voltammograms before and after the transformation.
Use of adiabatic calorimetry to characterise thermal runaway of Li-ion cells is a crucial technique in battery safety testing. Various states of charge (SoC) of Li-ion cells were investigated to ascertain their thermal runaway features using a Vent Sizing Package 2 (VSP2) adiabatic calorimeter. To evaluate the thermal runaway characteristics, the temperature-pressure-time trajectories of commercial cylindrical cells were tested, and it was found that cells at a SoC of greater than 50% were subject to thermal explosion at elevated temperatures. Calorimetry data from various 18650 Li-ion cells with different SoC were used to calculate the thermal explosion energies and chemical kinetics; furthermore, a novel self-heating model based on a pseudo-zero-order reaction that follows the Arrhenius equation was found to be applicable for studying the exothermic reaction of a charged cell.
This paper explores and proposes a structure–conductivity correlation in the PEO:LiBF4–MgO composite electrolyte system. The proposed correlation is derived from interpretations of DSC and conductivity measurements. Thermal cycling in the 0–100°C range yields an amorphous polymer structure believed to be beneficial for enhanced conductivity. The proposed roles of MgO are to depress the PEO melting temperature and retard the kinetics of its crystallization. A resistivity relaxation or conductivity enhancement below the melting temperature of PEO (68°C) occurs, which appears to be a characteristic of these electrolytes and related to an interaction of dipoles associated with polymer chains and MgO. A higher concentration (≃30%) of MgO leads to its segregation and reduction in conductivity resulting from crystallization of PEO.
Research on sodium based electrolytes and batteries have received the researcher’s attention as it may fulfill the energy storage needs, especially the grid level requirements where cost is as important as the performance. The present paper reports experimental investigations on carbonate free Na-ion conducting gel polymer electrolytes prepared by entrapment of sodium triflate salt in ionic liquid into poly (vinylidinefluoride-co-hexafluoropropyline) polymer matrix. This electrolyte system is subjected to X-ray diffraction and differential scanning calorimetry to probe changes in structural and thermal properties. The electrochemical impedance spectroscopy technique is employed to determine the bulk resistance and ionic conductivity of the polymer gel electrolyte system. In order to investigate the temperature dependent dielectric behavior of electrolyte system, real part of the permittivity and dielectric loss are discussed as a function of frequency. The open circuit voltage and discharge capacity is recorded to determine the initial voltage obtainable and discharge profile for the prototype sodium-sulfur cell. The investigations reveal that ionic liquid based electrolytes appear to be valid candidates to replace the unstable and flammable conventional carbonate for their use in fabricating electrolytes for future sodium-sulfur batteries.
The oxidative polymerization of aniline was investigated using H2O2 as an oxidant and metallic gold as a catalyst. In the form of colloidal nanoparticles, gold produces the conductive polyaniline only in a low yield, whereas when supported on carbon and titania, it improves the polymerisation reaction. For an Au/TiO2 catalyst, a synergistic effect between the metal and the support has been demonstrated that allows the production of polyaniline at high yield (70%). Morphological aspects, derived by TEM and SEM techniques, allow identification of the polymeric material in form of nanospheres 45–600 nm in diameter.
In this work, 1, 3, 5-Pentanetricarbonitrile (PTN) is adopted as a novel electrolyte additive to improve the electrochemical characteristics of LiCoO2 cathode operating under high charging cut-off voltage. PTN additive generates an extremely stable CEI film with abundant of CN bond and higher content of LixPOyFz/LixPFy on the LiCoO2 cathode surface, which is beneficial to inhibit the continuous decomposition of electrolyte and decrease the interfacial impedance. With electrolyte containing 0.5 wt.% PTN, the LiCoO2 cathode shows an initial capacity of 180.1 mAh g−1 with a columbic efficiency of 94.0%, and achieves a capacity retention of 90.7% for 300 cycles at 3.0–4.45 V. It makes the mass specific energy density of LCO cathode increases from 564.7 Wh kg−1 to 728.7 Wh kg−1, which leads to nearly 30% of the additional energy.
A new thermodynamic model is developed based on the extended perturbed hard sphere chain (PHSC) model and melting point depression theory to describe the phase behaviors of copolymer electrolyte/salt systems. The phase behaviors of poly(ethylene oxide-block-propylene oxide)/LiCF3SO3 systems are investigated by thermo-optical analysis (TOA) technique. Quantitative descriptions according to the proposed model are in good agreement with experimental data. The obtained results show that monomer ratio and sequence type of copolymers play a great role in determining eutectic points of the given systems.
We report the influence of synthesis techniques on the structural and electrochemical behavior of cobalt-free, low-cost and eco-friendly layered type Li1+x (Mn0.4Ni0.4Fe0.2)1−x O2 (0< x <0.4) cathodes for Li-ion batteries. Layered phase, Li1+x (Mn0.4Ni0.4Fe0.2)1−x O2 (0< x <0.4) was prepared by sol–gel, co-precipitation, acetate precipitation and mixed hydroxide method and by subsequent sintering at 700°C under oxygen flow. X-ray diffraction experiments revealed the presence of α-NaFeO2 type structure with R 3 ¯ m space group in the prepared materials. Among the layered phase compounds, material prepared by mixed hydroxide method delivered maximum reversible capacity of 207mAhg−1 at current density of 0.1mAcm−2 between 2 and 4.5V vs. Li with excellent capacity retention characteristics as well. In addition, influence of “x” on electrochemical properties of Li1+x (Mn0.4Ni0.4Fe0.2)1−x O2 (0< x <0.4) were also investigated and such samples were prepared by mixed hydroxide route.
A Mobile Wireless Sensor Network (MWSN) is composed of mobile sensor nodes, whereby the life time of a sensor is specified by the life time of its battery. MWSN is used to measure a mobile object parameters then transmit the sensed data to center station called Sink Node (SN). Routing of the sensed data is a challenging issue since several parameters and restrictions should be managed carefully in MWSN. Although the sensor's power (e.g., sensor's battery level) is a critical issue, managing data transmission time is also a considerable subject especially for real time applications. Several routing protocols had been proposed for MWSN, however, each protocol considers a single type of awareness (such as; long life, delay time, total energy…). While some protocols consider the sensor's energy to maximize the network lifetime, others aim to find the shortest path to reach the destination. In this paper, a multi-aware query driven (MAQD) routing protocol will be proposed for MWSN based on a neuro-fuzzy inference system. MAQD considers four types of awareness; the long life of the sensor, delay time of data transmission, total cost of the network, and the shortest transmission path. Hence, based on the selected type of awareness, a fuzzy inference system selects the proper path for routing data. MAQD is a query driven protocol, accordingly, SN can collect data from some/all sensors by employing a request (REQ) message in which the awareness type is specified. MAQD is simulated and tested using OPNET 14.5 and compared with the latest MWSN routing protocols. Simulation results have shown that MAQD outperforms the selected competitors routing protocols (LEACH, ERTLD, RACE, SPIN, EAR2, DCBM, and Rumor routing) as it introduces the best data delivery with the minimum routing overheads in terms of time penalties and power consumed.
This paper explores the combination of a sodium–nickel chloride (ZEBRA) battery and an intermediate temperature solid oxide fuel cell (IT-SOFC) to form a hybrid power system that is intended for automotive applications. A range of vehicle types, drive cycles and fuels are investigated and compared in terms of their suitability for the pairing of this particular fuel cell and battery technology. In order to avoid the problem of stop–start cycles and load transients on the SOFC, a nominally ‘always-on’ strategy is investigated for the fuel cell. Sizing of the system is performed for each vehicle/drive cycle by adopting the minimum fuel cell power and battery energy in order to preserve charge neutrality over a 24h period, while accommodating the requisite vehicle performance characteristics. Weight and volume estimates are reported for the hybrid system and opportunities for efficiency improvement brought about by synergistic operation of the fuel cell and the battery are discussed.
Powdery Mn3O4 and Mn2O3 electrodes with carbon and binding polymer were electrochemically stimulated and activated by successive potential cycles in a mild aqueous electrolyte containing alkali sulfate. The activation of the manganese oxides is affected by the electrode material, milling treatment, potential region, and electrolyte solution. It is found that the ball-milled Mn3O4 electrode demonstrated the highest specific capacitance, 190Fg−1, in 1moldm−3 Na2SO4 aqueous solution due to the phase transition from Mn3O4 to electrochemically active birnessite, Na y MnO2·nH2O. The increase in capacitance originated from the formation of birnessite possessing highly porous morphology. The nano-structured birnessite demonstrated long cycle life of about 2000 cycles with acceptable capacitance retention of 190–160Fg−1. The birnessite was applied as positive electrode of the asymmetric electrochemical capacitor with activated carbon negative electrode in the mild aqueous solution.
Structural and stoichiometric alterations in cathode materials with high intercalation voltages have been a bottleneck for next generation lithium ion batteries. Moreover, structure damage with the slightest of temperature elevation is predominant in known cathode systems. Monoclinic Li3V2(PO4)3 (LVP) with high intercalation voltage (>4.0 V) is a potential high-power cathode for lithium ion batteries owing to extraordinary stability of the phosphate anion framework. However, severe vanadium dissolution and lattice re-arrangement remains the biggest nuisance. Modification of electron conduction pathways by doping LVP lattice with Cr3+ is studied here and the efficacy of Cr3+ to stabilize the structure is understood. Vacant d-orbital sites in Cr3+ promote de-localization of electrons suppressing disproportionation and hence vanadium dissolution resulting in improved electrochemical performance for robust cycling conditions. Significant enhancement in specific capacity retention (from 26% to 84%) and improved cycle life of 400 high power cycles was observed on doping suggesting excellent performance of the cathode at high temperature (60 °C) environments.
Porous zinc electrodes are elaborated, assembled in Zn/Ni 3–4 Ah prismatic batteries and monitored upon charge/discharge cycling (150 cycles at C/3 rate followed by 150 cycles at 1C rate). Migration of zinc within the thickness of the zinc electrodes is revealed by X-Ray radiography, scanning electron microscopy, and X-EDS elemental cartography. Electrodes using either zinc oxide plus calcium hydroxide or directly calcium zincate as active material show similar behavior: neither dendrite formation nor morphological shape changes are observed after 300 charge/discharge cycles. Upon cycling, zinc accumulates at the core of the porous electrode, in the vicinity of the primary current collector and not at the surface, therefore avoiding any risk of dendrite formation. This suggest that the electrode operation is controlled by a core-shell mechanism, with a core of active zinc in the vicinity of the primary current collector, trapped in an electrode shell which is created by the outer portion of the electrode (active material, conductive additives, binder …). However, changing from C/3 to 1C rate after 150 cycles significantly improves the capacity of batteries using calcium zincate; this is correlated to its initial atomic homogeneity associated with higher porosity and an optimal electronic percolation.
Solar technologies can contribute to reaching the binding climate target of the Nordic countries. The application of two solar assisted solutions has been assessed for an office building located in Finland. The first one is a solar assisted absorption heat pump, which uses solar collectors and district heating as the main heating source. The other solution is a photovoltaic (PV) driven air source heat pump. The solar assisted absorption heat pump is able to upgrade the low temperature (5–10 °C) solar thermal energy into useful heat for building heating supply (renewable energy share of the heating season is about 19%), demonstrating that solar thermal energy can effectively contribute to supplying heat to buildings also in Northern European countries. The solar assisted absorption heat pump shows higher renewable energy share than the PV driven heat pump when comparing system solutions with the same area of installed solar technologies. However, the cost analysis shows that the electrically driven system is more economical viable. In a 15-year timescale, the cost of the electrically driven system is almost half of the thermally driven system. Therefore, costs of this solution have to considerably decrease to make solar assisted absorption heat pump competitive in Northern Europe.
A search for high-efficiency electrode materials is crucial for the application of Li-ion batteries (LIBs). Using density functional theory (DFT), we assess the Mn2C sheet, a new MXene, as a suitable electrode material. Our studies show that Li atoms can bind strongly to the Mn2C sheet, with low adsorption energy of −1.93eV. A pristine Mn2C sheet exhibits metallic characteristic, offering an intrinsic advantage for the transportation of electrons in material. A very low energy barrier of 0.05eV is predicted, showing that Li ion can easily and freely migrate on the Mn2C sheet. In addition, with the increase of Li content, adsorption energy varies minimally within a range of energy that spans only 0.27eV, showing that lithiation to a high content is feasible. Furthermore, we found that, because of the bilayer adsorptions on both sides of the Mn2C sheet, the theoretical capacity of the Mn2C sheet is 879mAhg−1, which is greater than that of most two-dimentional (2D) electrode materials. All these results reveal a new promising MXene material for LIBs. We also studied the effects of oxidation and fluorination on the electrochemical properties of the Mn2C sheet and found that oxidation and fluorination will fade the electrochemical properties of the Mn2C sheet in general.
Overcharge protection is not only critical for preventing the thermal runaway of lithium-ion batteries during operation, but also important for automatic capacity balancing during battery manufacturing and repair. A redox shuttle is an electrolyte additive that can be used as intrinsic overcharge protection mechanism to enhance the safety characteristics of lithium-ion batteries. The advances on stable redox shuttles are briefly reviewed. Fundamental studies for designing stable redox shuttles are also discussed.
NMR spectroscopy continues to evolve, with publications in 2008 providing an eclectic collection of applications, advances and incremental improvements. This article covers rapid acquisition methods, DNP, force-microscopy, SQUID, traditional solids and liquids, solid-state, and computational aspects of NMR spectroscopy. I am indebted to the great and the good whose work has been reported here, all credit is theirs; errors, omissions and blame are all mine.
The Adolescent Brain Cognitive Development (ABCD) study is poised to be the largest single-cohort long-term longitudinal study of neurodevelopment and child health in the United States. Baseline data on N = 4521 children aged 9–10 were released for public access on November 2, 2018. In this paper we performed principal component analyses of the neurocognitive assessments administered to the baseline sample. The neurocognitive battery included seven measures from the NIH Toolbox as well as five other tasks. We implemented a Bayesian Probabilistic Principal Components Analysis (BPPCA) model that incorporated nesting of subjects within families and within data collection sites. We extracted varimax-rotated component scores from a three-component model and associated these scores with parent-rated Child Behavior Checklist (CBCL) internalizing, externalizing, and stress reactivity. We found evidence for three broad components that encompass general cognitive ability, executive function, and learning/memory. These were significantly associated with CBCL scores in a differential manner but with small effect sizes. These findings set the stage for longitudinal analysis of neurocognitive and psychopathological data from the ABCD cohort as they age into the period of maximal adolescent risk-taking.
Li(Li1/3Ti5/3)O4 or (Li4Ti5O12) (LTO) grains are prepared via electrospinning a solution containing lithium acetate, titanium tetra(IV)-isopropoxide, polyvinyl acetate and acetic acid in N,N-dimethyl-formamide, followed by a subsequent sintering process. The structures and morphology were characterized by X-ray diffraction, scanning and transmission microscopy. Coin-type cells were assembled to test the electrochemical performance was evaluated using galvanostatic cycling at room temperature, in the cycling range, 1.0–2.8V. The Li-cycling results showed characteristic discharge-charge plateaus at 1.55 and 1.8V vs. Li/Li+, respectively. Electrospun LTO showed a reversible capacity of 165(±3)mAhg−1 at the end of 10th cycle at a current rate of 0.2C. The later studies on rate capacities and cycling performance of LTO grains demonstrate good rate performance and long term cycling stability. Galvanostatic Intermittent Titration Technique (GITT) and Electrochemical Impedance Spectroscopy (EIS) studied were carried out at end of 381st and 382nd cycle to understand the electrode kinetics.
Objective This study investigated the effectiveness of an ERP-compatible Digit Span Backward (ERP-DB) task to determine working memory abilities in healthy participants. Methods Participants were administered both the standard digit span backward and ERP-DB tasks. The ERP-DB task was divided into two sections, consisting of 2, 4, 6 and 8 (Group 1) and 3, 5, and 7 (Group 2) set sizes. A set of digits was aurally presented, followed by a second set that either corresponded to the reverse order of the first set (correct condition) or had one digit in the sequence replaced by an incorrect digit (incorrect condition). Results Two posterior positive components were found to distinguish the two conditions; an earlier positive component (P200/P300) was elicited in the correct condition, whereas a comparatively robust and prolonged positive slow wave (PSW) was elicited in the incorrect condition. Furthermore, the PSW and the difference in PSW amplitude between incorrect and correct conditions (dPSW) dissipated as working memory load increased and were related to working memory capacity. Conclusions The PSW, dPSW and P200/P300 components were found to be associated with working memory abilities and may have the potential to act as neurophysiological markers for the assessment of working memory capacity. Significance This research lends support for the utility of the ERP-DB task as a means of assessing working memory abilities, which may have implications for testing patients with expressive communication impairments.
Semitransparent flexible polymer solar cells were manufactured in a full roll-to-roll process under ambient conditions. After encapsulation a silver based circuit was printed onto the back side of the polymer solar cell module followed by sheeting and application of discrete components and vias. The discrete components were white light LEDs, a blocking diode, a lithium ion battery, vias and button contacts in two adjacent corners. The completed lamp has outside dimensions of 22.5 × 30.5 cm, a weight of 50 g and a very flat outline. The battery and components were the thickest elements and measured < 1 mm. A hole with a ring was punched in one corner to enable mechanical fixation or tying. The lamp has two states. In the charging state it has a completely flat outline and will charge the battery when illuminated from either side while the front side illumination is preferable. When used as a lamp two adjacent corners are joined via button contacts whereby the device can stand on a horizontal surface and the circuit is closed such that the battery discharges through the LEDs that illuminate the surface in front of the lamp. Several different lamps were prepared using the same solar cell and circuitry while varying the amount of white LEDs employed and by variation of the number of batteries and the individual battery capacity. The lamp prototype was developed through two early prototypes and the final and serially produced prototype was subjected to field tests in Zambia. Some of the lamps were recovered and the experiences gained with the prototype are presented allowing for further development that takes systemic factors such as the immediate response and spontaneous handling of the lamp by someone with no prior knowledge of the lamp or its workings.
Li2FeSiO4/C composites doped by vanadium at Fe/Si sites have been investigated as cathode materials for lithium ion batteries. Effects of vanadium substitution at different sites on the structure of Li2FeSiO4/C are examined by X-ray diffraction, X-photoelectron spectroscopy and scanning electron microscopy. XPS results show that the oxidation state of vanadium doped at Fe sites is +3, whereas is +5 when doped at Si sites. Electrochemical measurements show that the Li2FeSi0.9V0.1O4/C sample exhibits the best electrochemical performance with initial discharge capacity of 159mAhg−1 and excellent cyclability with capacity of 145mAhg−1 at 30th cycle, which can be ascribed to larger cell volume and higher lithium ion diffusion coefficient, however, the initial discharge of the Li2Fe0.9V0.1SiO4/C sample is only 90% of the undoped Li2FeSiO4, which can be attributed to the loss of Fe content.