batterydata/paper-abstracts huggingface dataset:
As modern energy storage needs become more demanding, the manufacturing of lithium-ion batteries (LIBs) represents a sizable area of growth of the technology. Specifically, wet processing of electrodes has matured such that it is a commonly employed industrial technique. Despite its widespread acceptance, wet processing of electrodes faces a number of problems, including expensive and dangerous solvent recovery, cut-off waste, coating inconsistencies, and microstructural defects due to the solvent drying process. This review considers each of these issues and discusses which electrode slurry properties should be considered when optimizing wet slurry fabrication. Simultaneously, methods to replace traditional wet processing of electrodes are being extensively researched. Some of these novel electrode manufacturing techniques prioritize solvent minimization, while others emphasize boosting energy and power density by thickening the electrode and, subsequently, creating an organized pore structure to permit faster ion diffusion. This review contemplates the advantages and disadvantages of each of these approaches and provides a comprehensive outlook on the future of electrode manufacturing.
Bilayered nanofilm electrodes made of polypyrrole (Ppy) and poly-2,5-dimercapto-1,3,4-thiadiazole (poly-DMcT) are produced by electrochemical means onto a carbon-fiber substrate, with the goal of preventing the loss of the electroactive mass of the disulfide and improving the electrode stability during the charge/discharge cycling process. Lightweight and high surface area composites are obtained by potentiostatically depositing a nanometric layer of Ppy onto a carbon fiber piece already supporting a layer of a potentiodynamically obtained poly(DMcT) film. The growth charge/mass ratio for the bilayered polymeric electrode is optimized, leading to a high electrochemical performance cathode with a stable specific capacity of ∼320mAhg−1 after 100 cycles.
Ethyl-(2,2,2-trifluoroethyl) carbonate (ETFEC) is investigated as a solvent component in high-voltage electrolytes for LiNi0.5Mn1.5O4 (LNMO). Our results show that the self-discharge behavior and the high temperature cycle performance can be significantly improved by the addition of 10% ETFEC into the normal carbonate electrolytes, e.g., the capacity retention improved from 65.3% to 77.1% after 200 cycles at 60 °C. The main reason can be ascribed to the high stability of ETFEC which prevents large oxidation of the electrolyte on the cathode surface. In addition, we also explore the feasibility of electrolytes using single fluoriated-solvents with and without additives. Our results show that the cycle performance of LNMO material can be greatly improved in 1 M LiPF6 + pure ETFEC-solvent system with 2 wt% ethylene carbonate (EC) or ethylene sulfate (DTD). The capacity retention of the LNMO materials is 93% after 300 cycles, even better than that of carbonate-based electrolytes. It is shown that the additives are oxidized on the surface of LNMO particles and contribute to the formation of cathode/electrolyte interphase (CEI) films. This composite CEI film plays a crucial role in suppressing the serious decomposition of the electrolyte at high voltage.
Durability issues in fuel cells, due to chemical and mechanical degradation, are potential impediments in their commercialization. Hydrogen leak development across degraded fuel cell membranes is deemed a lifetime-limiting failure mode and potential safety issue that requires thorough characterization for devising effective mitigation strategies. The scope and depth of failure analysis has, however, been limited by the 2D nature of conventional imaging. In the present work, X-ray computed tomography is introduced as a novel, non-destructive technique for 3D failure analysis. Its capability to acquire true 3D images of membrane damage is demonstrated for the very first time. This approach has enabled unique and in-depth analysis resulting in novel findings regarding the membrane degradation mechanism; these are: significant, exclusive membrane fracture development independent of catalyst layers, localized thinning at crack sites, and demonstration of the critical impact of cracks on fuel cell durability. Evidence of crack initiation within the membrane is demonstrated, and a possible new failure mode different from typical mechanical crack development is identified. X-ray computed tomography is hereby established as a breakthrough approach for comprehensive 3D characterization and reliable failure analysis of fuel cell membranes, and could readily be extended to electrolyzers and flow batteries having similar structure.
During the discharge process of lithium-sulfur batteries, the nucleation and growth of Li2S precipitates result in a non-uniform Li2S particle size distribution, significantly affecting the charging process. However, a uniform Li2S distribution at the initial state of the charging process of the batteries is assumed in the models reported in the literature, leading to an unrealistic simulation of the charging process. To address this issue, we propose a one-dimensional transient mathematical model, which incorporates the size-dependent Li2S dissolution and redox mediation reaction between dissolved polysulfides and Li2S particles into the charging process. Simulation results show that the dissolution rate of large Li2S particles is suppressed at a lower potential due to the small specific surface area, while the smaller Li2S particles are electrochemically oxidized into dissolved polysulfides first, which further act as the redox mediators to promote the oxidation of larger Li2S particles. Capturing these effects enables an excellent agreement between the predicted and measured charging voltage profiles. Moreover, the effects of particle sizes and redox mediation reaction rates are studied. It is revealed that the optimal amount of smaller-sized Li2S particles and suitable redox mediation reaction rate allow for a lower charging over-potential. Furthermore, it is shown that the effect of redox mediation rates on the dissolution of Li2S large particles exerts a significant influence on the charging process.
Catalysts for oxygen reduction reaction (ORR) are crucial in fuel cells. Developing metal-free catalyst with high activity at low-cost and high-volume production remains a great challenge. Here, we report a novel type of nitrogen-doped nanoporous carbon nanosheets derived from a conveniently available and accessible plant, Typha orientalis. The nanosheets have high surface area (the highest surface area can be 898 m2 g−1), abundant micropores and high content of nitrogen (highest content of 9.1 at.%). The typical product exhibits an unexpected, surprisingly high ORR activity. In alkaline media, it exhibits similar catalytic activity but superior tolerance to methanol as compared to commercial 20% Pt/C. In acidic media as well, it shows excellent catalytic ability, stability and tolerance to methanol. This low-cost, simple and readily scalable approach provides a straightforward route to synthesize excellent electrocatalysts directly from biomass, which may find broad applications in the fields of supercapacitors, sensors, and gas uptake.
Single crystalline Na2V6O16·2.36H2O nanowires are synthesized by a facile hydrothermal method as a new cathode material for Li-ion battery. The nanowires show a diameter of 60–100nm and a length of up to 5μm. Appropriate thermal treatment could effectively improve the cycling performance, although the discharge capacity is sacrificed to some extent. Na2V6O16·0.86H2O after heat treatment under 300°C delivers an initial specific discharge capacity of 235.2mAhg−1 at 30mAg−1, with a capacity retention of 91.1% after 30 cycles. Long cycling test is demonstrated by the retention of 90.4% and 94.4% at 150 and 300mAg−1, respectively, after 80 cycles. Good rate capability is also achieved for this material. It is proposed that the improved cycling stability of the electrode after thermal treatment is mainly attributed to the removal of a part of crystal water, accompanied with certain structural arrangement.
Li–S batteries are a low-cost and high-energy storage system but their full potential is yet to be realized. This Review surveys recent advances in understanding polysulfide chemistry at the positive electrode and the electrolyte and discusses approaches towards long-life and high-loading batteries.
Electrochemical experiments that intend to characterise the state of charge (SOC) of lead–acid battery positive plates are presented. These experiments are designed for potential battery plate production quality control and in situ monitoring of battery condition. A small size probe, consisting of a counter and a reference electrode encased in a glass body ending to a fine aperture tip and pressed onto the specimen, was used to apply cathodic galvanostatic pulses on positive plate battery samples. Although this probe arrangement is similar to that of a coulometric thickness gauge, the porous nature of the battery plate results eventually in full discharge of the entire specimen. However, during the initial stages of specimen discharge using the contact probe, a potential arrest was observed for fully charged and partially discharged samples and it was attributed to the time needed for the thickness of a PbSO4 film formed during discharge and the corresponding resistance under the probe’s tip to reach a critical value for the discharge to spread to the rest of the sample. The duration of this potential arrest was found to be related to the positive plate’s SOC indicating the possibility of using the technique in positive plate quality control or in situ monitoring.
LiNi0.8Co0.2O2 as the cathode material for a lithium ion battery was prepared by two different methods, sol–gel method and the solid-state reaction process. The samples were characterized and tested by means of XRD, SEM, particle size analysis, BET, and electrochemical methods. The results of XRD show that both the LiNi0.8Co0.2O2 samples prepared by two different methods are isostructural with α-NaFeO2 with a space group R-3m. The results of electrochemical studies show that the sample prepared by the solid-state reaction process is superior to that by the sol–gel method in electrochemical performance.
Understanding the origins of high overpotentials required for Li2O2 oxidation in Li–O2 batteries is critical for developing practical devices with improved round-trip efficiency. While a number of studies have reported different Li2O2 morphologies formed during discharge, the influence of the morphology and structure of Li2O2 on the oxygen evolution reaction (OER) kinetics and pathways is not known. Here, we show that two characteristic Li2O2 morphologies are formed in carbon nanotube (CNT) electrodes in a 1,2-dimethoxyethane (DME) electrolyte: discs/toroids (50–200 nm) at low rates/overpotentials (10 mA gC−1 or E > 2.7 V vs. Li), or small particles (<20 nm) at higher rates/overpotentials. Upon galvanostatic charging, small particles exhibit a sloping profile with low overpotential (<4 V) while discs exhibit a two-stage process involving an initially sloping region followed by a voltage plateau. Potentiostatic intermittent titration technique (PITT) measurements reveal that charging in the sloping region corresponds to solid solution-like delithiation, whereas the voltage plateau (E = 3.4 V vs. Li) corresponds to two-phase oxidation. The marked differences in charging profiles are attributed to differences in surface structure, as supported by X-ray absorption near edge structure (XANES) data showing that oxygen anions on disc surfaces have LiO2-like electronic features while those on the particle surfaces are more bulk Li2O2-like with modified electronic structure compared to commercial Li2O2. Such an integrated structural, chemical, and morphological approach to understanding the OER kinetics provides new insights into the desirable discharge product structure for charging at lower overpotentials.
A polymer blend of a partially-branched phenyl-substituted polysilane, (Ph2Si)0.85(PhSi)0.15, and polystyrene (1:1 by weight) has been prepared to produce silicon oxycarbide (Si–O–C) composite materials through pyrolysis in the temperature range 700–1200 °C under an argon atmosphere. According to elemental analysis results, carbon is a major constituent in a series of Si–O–C composite materials obtained in this study. Completely amorphous features were observed for the composite materials obtained between 700 and 1100 °C, while a clearly discernible crystalline evolution of silicon carbide (SiC) phases was found in a glass network of the composite material obtained at 1200 °C. This paper also deals with electrochemical lithiation and delithiation for the series of Si–O–C composite materials. The first delithiation capacities of these composite materials were highly dependent on pyrolysis temperatures. The composite material obtained at 700 °C had the maximum delithiation capacity of ca. 800 mA h g−1, while the composite material obtained at 1200 °C showed the minimum delithiation capacity of ca. 330 mA h g−1. The crystalline evolution of SiC phases is thought to cause such a drastic decrease in delithiation capacity at 1200 °C.
Leukocytes containing opioid peptides locally control inflammatory pain. In the early phase of complete Freund’s adjuvant (CFA)-induced hind paw inflammation, formyl peptides (derived e.g. from Mycobacterium butyricum) trigger the release of opioid peptides from neutrophils contributing to tonic basal antinociception. In the later phase we hypothesized that toll-like-receptor-(TLR)-4 activation of monocytes/macrophages triggers opioid peptide release and thereby stimulates peripheral opioid-dependent antinociception.
In this study, a gel of graphene oxide (GO) and carbon nanorods obtained from the GO gel were synthesized via a modified Hummer’s method and a force-driven reflux process respectively. Scanning electron microscopy (SEM) was used to analyse the morphology of the as-synthesized materials showing gelatinous and nanorods structures for the graphene oxide and carbon materials respectively. X-ray diffraction (XRD) suggests that the synthesized materials have a hexagonal crystal structure and an increased interlayer spacing due to the interlaced molecules of oxygen-containing functional groups. X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDX) analysis were employed to confirm the presence of carbon and oxygen functionalities in the synthesized materials. Electrodes fabricated from both materials prove a limit specific capacitance of 436.5Fg−1 and 719.5Fg−1 corresponding to specific capacities of 48.5mAhg−1 and 80.8mAhg−1 at a current density of 0.5Ag−1 in a three electrode system with 6M KOH electrolyte for both the graphene oxide gel and carbon nanorods respectively. The materials show good cycle stability after 3000 cycling at a current density of 5Ag−1, which implies a great promise as electrodes for supercapacitor applications.
Li1+x Ni1/6Co1/6Mn4/6O2.25+x/2 (0.1≤ x ≤0.7) cathode materials have been synthesized by a simple carbonate co-precipitation method. The effects of the lithium content on the structure, physical property, and electrochemical performance of the samples have been investigated. As the increase of lithium content, the Li1+x Ni1/6Co1/6Mn4/6O2.25+x/2 evolves from a mixture of hexagonal R−3m, monoclinic C2/m, and spinel Fd−3m structure to a mixture of hexagonal and monoclinic structure, accompanied with less cation mixing between Li+ and Ni2+. The increase of x value also affects the size of the primary particles and the roughness of the secondary particles. The Li1+x Ni1/6Co1/6Mn4/6O2.25+x/2 with appropriate lithium content, e.g., x =0.3, thereby small particle size, high pellet density, and low cation mixing, brings on the largest discharge capacity, which is more than 288mAhg−1 in the voltage range of 2.0–4.8V at 25mAg−1, and the lowest irreversible capacity loss of 47mAhg−1 among these cathode materials.
Motor vehicles represent one of the widely owned assets in the US. A vehicle’s ownership cost includes fixed expenses to purchase and own the vehicle and variable costs to use and operate the vehicle. Policymakers, analysts and consumers are interested in understanding the total ownership costs of various vehicle types and technologies so as to understand their relative consumer preference and valuation. Plug-in hybrid electric vehicles are an advanced technology vehicle that is presently in limited production, but whose relative cost of ownership is not well-defined. A few studies have attempted to calculate the costs and benefits of PHEVs but none consider the cost and benefits of PHEVs at a level of detail comparable to what has been performed for other vehicle technologies. In order to understand the costs and benefits of PHEVs purchase and use, this study constructs a comprehensive ownership cost model. The model is then used to analyze different PHEV designs within four vehicle classes. This study then performs a sensitivity analysis to understand the sensitivity of total ownership cost and payback period to model parameters and the modeled components of ownership costs. Results show that a more comprehensive PHEV ownership cost model has a lower net cost of ownership than studies to date, resulting in a shorter payback period and higher consumer preference.
Formation of 3BS paste. Depending on the phase and chemical compositions of the cured paste the formation process can be divided in two stages: - first stage: PbO and basic lead sulfates are oxidized to α-PbO2; the plate potential is low; - second stage: PbSO4 is oxidized to β-PbO2; the plate potential under load is high.
Lithium metal thin films are deposited via an easy electrochemical route using standard carbonate based electrolyte with LiPF6 salt. Deposited films exhibit self-aligned nanorods structure without any dendritic growth. The electrochemical performance of such lithium electrodes is evaluated in coin cell configuration versus silicon thin films and no obvious difference in behavior is observed between electrodeposited lithium thin films and bulk lithium metal foils. The process is then used to manufacture all-solid-state thin film battery stacks composed of a silicon cathode, LiPON as solid electrolyte, copper as conductive layer for the electrodeposition process and electrodeposited lithium as anode material. Finally, the electrochemical performance (cycle life, specific capacity and curve shape) is close to those obtained with standard evaporated lithium. This new lithium film deposition technique is suitable for 3D textured or high roughness substrates and limited to electronic conductive surfaces. In the end, this enables a direct patterning of the lithium anode layer. Therefore, considering that all other microbattery materials can be structured by photolithography, the Li electrodeposition could avoid using shadow masking technique during the all-solid state microbatteries manufacturing process.
Physician-manned emergency medical teams supplement other emergency medical services in some countries. These teams are often selectively deployed to patients who are considered likely to require critical care treatment in the pre-hospital phase. The evidence base for guidelines for pre-hospital triage and immediate medical care is often poor. We used a recognised consensus methodology to define key priority areas for research within the subfield of physician-provided pre-hospital critical care.
Highly ordered and crystalline mesoporous In2O3 was synthesized using KIT-6 as the template and exhibited better electrochemical performance than its bulk counterpart. Moreover, it is interesting to note that the mesoporous In2O3 with small particle size showed enhanced performance compared to that with large particle size. However, the reversible capacity of mesoporous In2O3 still decreased remarkably, possibly owing to the collapse of mesopores during lithiation and delithiation processes. Therefore, these mesoporous In2O3 particles were further wrapped by graphene nanosheets through a stepwise heterocoagulation method. The graphene encapsulation may enhance the electrical conductivity of the overall electrode, avoid the aggregation of In2O3 particles and even stabilize the mesostructure of In2O3 during cycles, which is beneficial to improving the electrochemical properties of mesoporous In2O3 particles.
The oxygen reduction reaction has been studied on gas diffusion electrodes made with various activated carbon materials and on the edge/basal orientations of pyrolitic graphite. A MnO2 catalyst was loaded on all carbon surfaces. The MnO2 catalyst demonstrated significant catalytic activity for the oxygen reduction reaction. The specific catalytic activity was found to relate to the concentration of the edge orientation of carbon materials loaded with MnO2 catalyst. The higher the percentage of edge orientations, the higher the specific catalytic activity would be. MnO2 may not participate in the reduction of O2, but catalyze the disproportionation of HO2 −.
While perovskite solar cells have skyrocketed in recent years to power conversion efficiencies competitive with those of silicon and thin-film photovoltaics, the lagging behind stability stands in the way of commercialisation. In this review, we discuss the reasons and factors that induce the degradation in photovoltaic performance of perovskite solar cells, and furthermore, we summarise the most promising strategies to enhance the lifespan. We show that each component of the device, including the charge selective contacts, perovskite layer, and electrodes, can be engineered to reduce the influence of heat, UV light, oxygen, moisture and their synergetic effect on the operating lifetime of devices. We conclude that inorganic contacts and inorganic perovskite compositions are the most promising direction toward stable perovskite solar cells.
The exploration of cathode materials with high capacity and power, fast charge/discharge rate, long lifespan and broad temperature adaptability is a challenge for the practical application of lithium ion batteries. Here, submicro-sheet Li3V2(PO4)3/C (LVP/C) cathode materials have been successfully synthesized via a simple and universal phase-change method. This designed melting process increases the crystallinity and decreases the Li+ diffusion distance, which effectively enhances the cycling stability and rate performances of the LVP/C cathode materials. The LVP/C cathode materials exhibit high discharge specific capacity of 130 mAh g−1 in the first cycle. The capacity retention is almost 100% after 100 cycles. In addition, at 10 C, more than 80% of initial discharge capacity is retained after 800 cycles, indicating excellent cycle performance at high rate. Moreover, the synthesized LVP/C materials perform excellent low-temperature properties. At −20 °C, the specific capacity can reach 105 mAh g−1 at 0.5 C. This study provides a novel template-free synthesis method for nano/micro materials.
Objective To investigate the relationship between perception of comfort and electrolyte concentration and applied voltage during transcranial direct current stimulation (tDCS). Methods NaCl solutions (15, 140 and 220mM NaCl) or deionised water were used as electrolytes to dampen tDCS sponge electrodes. Subjects (14, 7M, 20–60years of age) rated comfort on an 11-point scale during 2min of tDCS (1mA). Results Overall participants rated tDCS as comfortable. Perception of comfort was negatively correlated with NaCl concentration (Spearman’s ρ =−0.88; p <0.05), and a logarithmic relationship was found between applied voltage and ionic strength of electrolytes (Pearson’s r =−0.635; p <0.01). There was no relationship between applied voltage and perception of comfort. Conclusions The application of NaCl solutions between 15 and 140mM to sponge electrodes is more likely to be perceived as comfortable during tDCS. Significance The reporting of solution concentration and ratings of perception would be useful adjuncts to tDCS studies.