batterydata/paper-abstracts huggingface dataset:
The main challenge of using TiO2 as anode for sodium-ion batteries (SIBs) is its inherent low electrical conductivity, which leads to its unsatisfied capacity, short cycle life and low initial Coulombic efficiency. Herein, we report that synergistically doped anatase TiO2 nanotubes with Ni and N via a simple sol-gel process, subsequent alkali-thermal reaction, and final thermal treatment in NH3 can optimize the relationship among the phase structure, electrical conductivity and sodium-ion diffusion kinetic performance of anatase TiO2 to enhance its sodium-ion storage and transport performances. The resultant Ni and N co-doped anatase TiO2 nanotubes (Ni-N/TNTs) exhibit a high charge capacity of 303mAhg−1 after 500 cycles at a current density of 50mAg−1 with an initial Coulombic efficiency of 65% and even at a high current density of 5Ag−1, a capacity of 143mAhg−1 is maintained after 8000 cycles with a capacity retention of ≥100%. The bandgap estimation, phase structure evolution, and electrochemical impedance spectroscopy analysis combined with the electrochemical test results indicate that the significantly improved sodium-ion storage and transport performances of Ni-N/TNTs should be mainly ascribed to the increased electrical conductivity, stable phase structure during the electrochemical processes, lower charge transfer resistance, and enhanced sodium-ion diffusion coefficient after Ni and N co-doping. The high capacity, improved Coulombic efficiency, excellent rate performance and long cycle life enable Ni-N/TNTs to be an applicable anode material for SIBs.
The primary mobility for persons with spinal cord injury (SCI) is seated. This article addresses ways to maximize the SCI patient’s functional mobility with proper prescription of seating. Critical components of seating are defined and goals for seating are identified. A format for a postural evaluation as a foundation for seating intervention is included. An overview of equipment for seating highlights unique features and components.
In this paper, Magneli phase Ti4O7 was successfully synthesized using a TiO2 reduction method, and characterized using X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The electrode coated with this Ti4O7 material showed activities for both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). For the ORR, several parameters, including overall electron transfer number, kinetic constants, electron transfer coefficient, and percentage H2O2 production, were obtained using the rotating ring-disk electrode (RRDE) technique and the Koutecky–Levich theory. The overall electron transfer number was found to be between 2.3 and 2.9 in 1, 4, and 6M KOH electrolytes, suggesting that the ORR process on the Ti4O7 electrode was a mixed process of 2- and 4-electron transfer pathways. Electrochemical durability tests, carried out in highly concentrated KOH electrolyte, confirmed that this Ti4O7 is a stable electrode material, suggesting that it should be a feasible candidate for the air-cathodes of zinc-air batteries. To understand the stability of this material, Raman and XPS spectra were also collected for the Ti4O7 samples before and after the stability tests. The results and analysis revealed that a thin layer of TiO2 formed on the Ti4O7 surface, which may have prevented further oxidation into the bulk of the Ti4O7 electrode.
This study reports iron phosphide (FeP) nanorod arrays on Ti substrates (FeP NRs/Ti) as anode for full sodium-ion batteries. The FeP nanorod arrays electrodes exhibit a high-rate capability of 414.7 mAh g−1 at 100 mA g−1 in the semi-battery tests (sodium foil as the counterpart) and 196.2 mAh g−1 at 2000 mA g−1. The high reversible capacity can be ascribed to an augmented sodium-ion diffusion coefficient (∼10−12 cm2 s−1) originated from the nanorod arrays. Besides, the binder-free and highly oriented- 1D FeP electrode helped to alleviate the volume change during (dis)charging processes thereby ensuring a long cycling life (207.7 mAh g−1 over 1000 cycles at 500 mA g−1). Electrochemical and ex-situ studies confirmed the significant contribution of pseudocapacitance to the highly electrochemical performance of FeP nanorod arrays. Most importantly, the sodium-ion full battery based on FeP NRs/Ti as anode and Na3V2(PO4)3 as cathode materials showed stable cycling performance over 200 cycles at a current rate of 1 C (1 C = 100 mA g−1, voltage range of 2.0–3.6 V), simultaneously possessing a high energy density of 185 Wh kg−1 at the power density of 200 W kg−1. We further successfully demonstrated an energy pack by combining four CH3NH3PbI3-xClx-based perovskite solar cells in series and a Na3V2(PO4)3-FeP NRs/Ti full sodium-ion battery, achieving a photoelectric conversion and storage efficiency of 5.2% under 1 sun light illumination.
Memory complaints are common among older adults with epilepsy (OAE), though discrepancy between subjective complaints and objective performance often exists. This study examined how accurately OAE and their informants reported on the participant's cognitive difficulties by comparing ratings of everyday cognition to objective performance. Thirty-seven OAE and 27 older adult controls completed a brief battery of neuropsychological tests, the Beck Depression Inventory, and the Cognitive Difficulties Scale (CDS). Each participant had an informant who completed the CDS. Older adults with epilepsy performed worse than controls on cognitive testing and reported more subjective cognitive complaints. Neither participant- nor informant-reported cognitive complaints were related to performance on any of the neuropsychological tests for either the group with epilepsy or control group, but both were related to greater depressive symptoms. Results suggest that subjective report of cognitive problems by both OAE and their informants may not reliably reflect the extent to which these problems exist.
An electrochemical quartz crystal microbalance study of platinum phthalocyanine thin films in aqueous media is presented. It has been shown that these films exhibit significant mass changes upon electrochemical cycling. These mass changes have been shown to be controlled by the ingress and egress of solvated anions during oxidation and reduction of the film, respectively. The mass changes within the film are shown to tend to steady state after a prolonged period of cycling. Chrono-amperometric studies have additionally shown that the movement of cations also has a role in the electrochemistry and mass transport within these films, but generally these events occur on a shorter timescale than those involving the solvated anions, and are hidden during most potential cycling studies.
Advanced thermal systems designed and fabricated through paraffinic phase change materials have emerged quite fast until recently. However, most of the prior works have reviewed the fabrication strategies to tailor the poor thermal characteristics of paraffin waxes, as well as compiled the application-oriented studies related to thermal/cold storage, thermal management of batteries, photovoltaics, buildings, and so forth. In the present review, the advanced thermal systems, manipulated through multifunctional inherent traits of paraffin waxes, have been reviewed and systematically categorized into thermo-management, thermo-mechanical, thermo-responsive and thermo-chemical systems. In addition, guided by the previously reported results for paraffinic thermal composites, it is hereby recommended to urgently promote the synergistic tradeoff between thermal conductivity improvement and latent heat reduction so as to avoid the thermo-physical bottlenecks and the design challenges in the future. Additional attempts include proposals of an ideal phase change diagram, serving as a guide to understand the phase change theory henceforth, and a categorical flow chart of thermal reinforcements leading to fundamental principles to fabricate an ideal thermal composite. In all, the effort is mainly dedicated to bridge the gap between broad fields where paraffin waxes have been, directly or indirectly, deployed. Therefore, fundamental terminologies are necessarily defined and tabulated to establish a closer-outlook for the experts of far-reaching fields.
Using GPS data logged for a representative sample of individual vehicles in private use, we assess the viability of plug-in hybrid electric vehicles (PHEVs) in Sweden for a wide range of techno-economic conditions. We determine requirements for PHEVs with the aid of a simple parameterization used to analyze the GPS data covering number of trips, driving distance per trip, and parking times, logged for 30days or longer, for 432 conventional Swedish cars. Good opportunities for charging and regular distances traveled between rechargings increase the potential for battery-powered driving and, along with a high annual mileage, enhance the viability of the PHEV. Therefore, commuters are likely to be the first drivers for whom the PHEV will be cost-effective. Making charging infrastructure available at work places would enhance the opportunity for this group of early adopters, as we show that charging while at work is comparable at the initial stage to halving the marginal battery costs for the average commuter.
Boron-doped diamond (BDD) electrodes have been modified by hydrous iridium oxide (IrO x ) electrodeposition, and depending on the deposition conditions, either highly dispersed iridium oxide nanoparticles or continuous oxide films were obtained. The electrochemical characteristics of IrO x on BDD compare well with those obtained on other substrate materials. The proposed method allows excellent control of the deposited amount, and high reproducibility of the electrochemical performance. Electrodes obtained by the deposition of a very low amount of IrO x (ca. 2 nmol cm−2) on the diamond surface exhibited an excellent analytical performance for hydrogen peroxide amperometric detection, that compares favorably with those obtained by using other substrate materials. Furthermore, these electrodes enabled H2O2 detection in neutral media, which is an advantage compared to sensors obtained by iridium oxide deposition on other substrates. The detection limit for H2O2 was ca. 10 times lower than that of commercially available platinum bulk electrodes. By proper selection of the diamond substrate structure, continuous IrO x layers of different thickness were formed. The IrO x /BDD electrodes have also exhibited excellent pH-sensing properties in a wide pH range, and high stability of the potentiometric response. These studies indicated that, by proper selection of the diamond substrate structure, robust IrO x layers could be prepared for use as H2O2 detection and pH sensors.
Objective We clinically tested a quantitative EEG method to localize abnormal variations in benzodiazepine-induced fast rhythms to localize focal epileptogenic lesions, assuming altered quality/quantity of GABA receptors in the lesions. Methods During a 64-channel-EEG (sampled at 1kHz) recording benzodiazepines were administered to five patients with localization related epilepsy associated with an MRI visible focal lesion. We determined the post-injection dominant spectral modulation using Gabor wavelets and analysed the symmetry of spatial distribution. This was compared to the localization of the lesion on the MRI scan. Results The principal component was found in the beta/gamma band. In all patients one region of decreased change was associated with the lesional hemisphere, and overlapped with the site of the lesion in four. Three patients underwent surgery: interictal corticographic findings concurred with the area of decreased benzodiazepine response. Conclusions This simple method localized abnormal function associated with epileptogenic lesions. Further methodological validation is now justified. Final clinical validation must be done in MRI-negative cases as well. Significance This research may lead to techniques for non-invasive easy localization of epileptogenic tissue that is not visible on a structural MRI scan.
The delegates to COP21 in Paris, in conjunction with nationally formulated commitments and pledges, resolved that countries should take actions to “hold the increase in global temperature to well below 2 °C above pre-industrial levels” and to achieve “a balance between anthropogenic emissions by sources and removal by sinks of greenhouse gases in the second half of this century”. This resolution for action suggests a step towards a global carbon emissions-control regime which, due to regional variabilities and remaining uncertainties as to the exact effects of atmospheric CO2 concentrations, must be considered within the purview of risk management. In this Opinion, four topics are discussed that intertwine science, technology, legal, and policy issues critical to the implementation of any global carbon emissions-control regime: (i) What to regulate and at what levels; (ii) Regulating short-term versus long-term emissions; (iii) Validation of compliance in a regulated global emissions regime; and, (iv) Legal aspects of geoengineering.
Poly (methyl methacrylate) (PMMA)-Reduced Graphene Oxide (rGO) (PrGO) composite films were fabricated by solvent evaporation technique and exposed to gamma radiation at different dosages viz. 25 kGy, 50 kGy and 100 kGy. The XRD analysis revealed the phases of PMMA and rGO and further confirmed the semi-crystalline nature of PMMA. The irradiation also decreased the peak intensities of the functional groups of PMMA and rGO. At 50 kGy irradiation, lamellar structures were formed on the surface of the films (50 kGy) due to the thermal fluctuations whereas, at higher dosage (100 kGy), pores were formed. The surface roughness and contact angle were enhanced on 50 kGy sample. The drug impregnated PrGO50 and PrGO100 samples showed sustained and burst release of drug respectively and in addition exhibited a better zone of inhibition against E. coli bacteria. All the samples were hemocompatible in nature. Fibroblast proliferation was enhanced with no cytotoxic effect on 50 kGy samples. Hence, the gamma irradiated samples could be an excellent candidate for biosensing and biomedical applications.
New plasticized polymer electrolytes were synthesized based on poly ethylene oxide (PEO), Poly (N,N-dimethylamino-ethyl-methacrylate) (PDMAEMA), LiN(CF3SO2)2 (LITFSI) as the salt and tetraethylene glycol dimethyl ether(tetraglyme) and EC + PC as plasticizers. The preparation and characterization of the polymer electrolytes were investigated as a function of temperature and various concentrations of LITFSI. Impedance spectroscopy and differential scanning calorimeter (DSC) were used to characterize the effects of various temperature, lithium salt concentration and two plasticizers on conductivity. The complex of PDMAEMA/PEO/LiTFSI/tetraglyme (S2) exhibits higher conductivity (4.74 × 10−4 Scm−1at 25°C) than PDMAEMA/PEO/LiTFSI/EC + PC (S1).
Reports on VAD device malfunction (DMF) focus primarily on the pump itself and fail to account for issues with the controller, power supply and other peripheral components. This single center experience with pulsatile (PU) and rotary (ROT) VAD's strives to identify the weakest links in total VAD reliability. DMF's were prospectively collected on all VAD's implanted between 01/2001 to 10/2010 and included: Thoratec PVAD (100 pts=16,383 pt-days), Thoratec Heartmate II (HMII)(73pts=19,934 pt-days), Ventrassist (22 pts=4,096 pt-days) and Heartware (17 pts=1,734 pt-days). DMF's were categorized as to primary pump failure (PF), Controller failure (CONTR), or DMF's due to peripheral component failure (PERPH). 80% of the Heartware, 78% of the Ventrassist and 60 % of the HMII pts had no DMF's while only 40% of the PVAD's did. Due to a more robust observation period, further results are focused on the HM II and PVAD pts. Cumulative DMF's by category are expressed as events/100 pt-days.Device MalfunctionsHMIIPVADCOMPONENT6 MO1 YEAR2 YEARS6 MO1 YEAR2 YEARSPUMP0.010.020.020.040.040.04Controller0.050.080.110.670.730.76Peripherals0.240.310.460.560.660.69Total0.290.420.591.261.411.48Cumulative Events/100 Pt-Days PF is rare but stable over two years for either VAD. CONTR DMF's increase slowly over two years but are 5 to 10 times higher for the PU VAD. CONTR and PERPH DMF's each account for about 50% of DMF's in PU VAD's. PERPH DMF's are the most common issue in ROT VAD's accounting for 82% of DMF's at 6 months and 78% at 2 years. Primary PF is a rare event for both rotary and PU VAD's. CONTR DMF's occur more frequently than PF in either VAD, but are 5 to 10 time more frequent in the PU devices. The most common DMF's in ROT VAD's are due to PERPH components such as drivelines, driveline connectors, batteries and other external components. This implies that more stringent pre-clinical reliability testing of peripheral components is warranted.
An integrated pyrolysis and chemical vapor deposition using CaCrO4 as a precursor were applied to convert mixed plastics into a nanocomposite comprising CaCr2O4 and carbon nanoplatelets (CaCr2O4/CNPs). During pyrolysis, plastics were decomposed into oil and non-condensable gas. While reacting with the precursor, non-condensable pyrolysis gas containing hydrocarbons and H2 played a dual role: (1) provided carbon for nanoplatelets growth and (2) facilitated reduction of Cr(VI) to Cr(III). Cyclic voltammetry demonstrated the synergistic effect of CaCr2O4 and CNPs on the heterogeneous electron transfer rate. The nanocomposite showed good performance as an electrocatalyst for oxygen reduction reaction increasing current density and reducing overpotential to −0.27 V vs Ag/Ag/KCl (sat.) at 0.06 mA cm−2. Furthermore, the nanocomposite exhibited a specific electrochemical capacitance as high as 60 F g−1 at 2 A g−1 and 67% stability over 3000 cycles, demonstrating the capability of electrode for fast charge/discharge, long cycling life and high reversibility.
With the advent of flexible electronics, flexible lithium-ion batteries have attracted great attention as a promising power source in the emerging field of flexible and wearable electronic devices such as roll-up displays, touch screens, conformable active radio-frequency identification tags, wearable sensors and implantable medical devices. In this review, we summarize the recent research progress of flexible lithium-ion batteries, with special emphasis on electrode material selectivity and battery structural design. We begin with a brief introduction of flexible lithium-ion batteries and the current development of flexible solid-state electrolytes for applications in this field. This is followed by a detailed overview of the recent progress on flexible electrode materials based on carbon nanotubes, graphene, carbon cloth, conductive paper (cellulose), textiles and some other low-dimensional nanostructured materials. Then recently proposed prototypes of flexible cable/wire type, transparent and stretchable lithium-ion batteries are highlighted. The latest advances in the exploration of other flexible battery systems such as lithium–sulfur, Zn–C (MnO2) and sodium-ion batteries, as well as related electrode materials are included. Finally, the prospects and challenges toward the practical uses of flexible lithium-ion batteries in electronic devices are discussed.
Nanocrystalline TiFe alloys with different morphology and microstructure were synthesized by mechanical alloying from the elemental powders with varied milling time. The particle morphology distinctly changes from globular to slaty between the 10th and 15th h of milling and then becomes spherical again after 30 h. The average particle size decreases continuously with milling time from about 50 μm (10 h milling) to 1–2 μm for the 30 h milled sample. X-ray diffraction analysis showed that after 15 h of milling alloying has already started. The initial mixture of metal powders transformed into amorphous or fine nanocrystalline material after 20 h. Further milling did not change the microstructure noticeably, i.e. it remaied nanocrystalline with some amount of amorphous fraction. Nanocrystalline Fe was also present in the end product. DTA analysis displayed exothermic effects due to crystallization reactions, revealing that the end product also contains the amorphous phase.
Water management is a significant challenge in portable polymer electrolyte membrane (PEM) fuel cells and particularly in proton exchange membrane (PEM) fuel cells with air-breathing cathodes. Liquid water condensation and accumulation at the cathode surface is unavoidable in a passive design operated over a wide range of ambient and load conditions. Excessive flooding or dry out of the open cathode can lead to a dramatic reduction of fuel cell power. We report a water management design based on a hydrophilic and electrically conductive wick. A prototype air-breathing fuel cell with the proposed water management design successfully operated under severe flooding conditions, ambient temperature 10°C and relative humidity of 80%, for up to 6h with no observable cathode flooding or loss of performance.
Nanowire K0.19MnO2·0.2H2O is prepared by a hydrothermal method. It presents better electrochemical behavior than K0.45MnO2·0.3H2O from the solid-state method. The capacitance of nanowire K0.19MnO2·0.2H2O (148 F g−1) is much higher than that of K0.45MnO2·0.3H2O (132 F g−1). It presents excellent cycling performance even when the oxygen in the aqueous electrolyte is not removed, and there is no evident capacitance fading after 2500 cycles. The supercapacitor based on activated carbon and nanowire K0.19MnO2·0.2H2O delivers an energy density 41.3 Wh kg−1 (based on the total mass of the active electrode materials) at a power density of 156.8Wkg−1, higher than that based on activated carbon and K0.45MnO2·0.3H2O, 28.4W h kg−1 at a power density of 115.1Wkg−1. In combination with our former work, it suggests that both the nano structure and the surface area are important to the capacitance of KxMnO2 especially the latter.
A critical bottleneck in the development of aqueous electrochemical energy storage systems is the lack of viable complete cell designs. We report a metal-free, bipolar pouch cell designed with carbon black/polyethylene composite film (CBPE) current collectors as a practical cell architecture. The light-weight, corrosion-resistant CBPE provides stable operation in a variety of aqueous electrolytes over a ∼2.5 V potential range. Because CBPE is heat-sealable, it serves simultaneously as both the pouch cell packaging and seal in addition to its use as a current collector. Although this non-metallic composite has a low electrical conductivity relative to metal foils, current travels only a short distance in the through-plane direction of the current collector in the bipolar cell configuration. This shorter path length lowers the effective electrical resistance, making the design suitable for high-power applications. We test the cell architecture using an aqueous ZnBr2 battery chemistry and incorporate tetrabutylammonium cations to improve the intrinsic low Coulombic efficiency and fast self-discharge of non-flow ZnBr2 cells. These devices demonstrate a cell-level energy density of 50 W h L−1 at a 10C rate (0.5 kW L−1), with less than 1% capacity loss over 500 cycles. A large-area (>6 cm2) 4-cell stack is built to illustrate that the pouch cells are scalable to practical dimensions and stackable without sacrificing performance. The device operates in the range of 6–7 V and has an internal self-balancing mechanism that prevents any individual cell in the stack from overcharging. The results thus demonstrate both a conceptually new cell architecture that is broadly applicable to many aqueous electrolyte chemistries and a specific high-performance example thereof.