batterydata/paper-abstracts huggingface dataset:
The lithium/sulfur (Li/S) battery is a promising electrochemical system that has a high theoretical capacity of 1675mAhg−1. However, the system suffers from several drawbacks: poor active material conductivity, active material dissolution, and use of the highly reactive lithium metal electrode. In this study, we investigated the electrolyte effects on electrochemical performances of the Li/S cell, by acting on the solvent composition. As conventional carbonate-based electrolytes turned out to be unusable in Li/S cells, alternative ether solvents had to be considered. Different kinds of solvent structures were investigated by changing the ether/alkyl moieties ratio to vary the lithium polysulfide solubility. This allowed to point out the importance of the solvent solvation ability on the discharge capacity. As the end of discharge is linked to the positive electrode passivation, an electrolyte having high solvation ability reduces the polysulfide precipitation and delays the positive electrode passivation.
Although tomato seeds (an industrial by-product) are known to contain several bioactive compounds, studies describing their health effects are limited. Previously, we evidenced that aqueous extract of tomato seeds (TSE) markedly attenuated rotenone (ROT)-induced oxidative stress and neurotoxicity in Drosophila system. This study investigated the neuroprotective effect of TSE in a chronic ROT model of neurotoxicity in mice. Initially, we assessed the potential of oral supplements of TSE to modulate the levels of endogenous markers of oxidative stress in brain regions of mice. Subsequently, employing a co-exposure paradigm, the propensity of TSE (100 mg/kg bw, 3 weeks) to attenuate ROT-induced behavioral phenotype (gait abnormalities, anxiety-like state), oxidative dysfunctions and neurotoxicity was examined. We found that mice provided with TSE supplements exhibited progressive improvement in gait pattern and exploratory behavior. TSE markedly offset ROT-induced oxidative impairments, restored reduced glutathione levels, antioxidant defenses (superoxide dismutase, glutathione peroxidase) and protein carbonyls content in brain regions. Specifically, TSE effectively diminished ROT induced elevation in the activity levels of acetylcholinesterase and restored the dopamine levels in striatum. Interestingly, in mitochondria, TSE was able to restore the activity of mitochondrial complexes and redox state. Collectively, our findings in the chronic ROT model demonstrate the ability of TSE to alleviate behavioral phenotype, oxidative stress, mitochondrial dysfunction and neurotoxicity. Further studies in dopaminergic cell models are necessary to understand the precise molecular mechanism/s by which tomato seed bioactives offer significant neuroprotection.
Structural instability due to intercalation-induced stresses in electrode materials is one of the key degradation mechanisms of Li-ion batteries. Fragmentation of material degrades structural integrity and electrical resistance, and also accelerates harmful side reactions. In situ experiments are the appropriate approach for investigating the actual time-dependent nature of the behavior changes of an electrode material while it is charged and discharged. In the current work, a unique in situ electrochemical atomic force microscopy (ECAFM) measurement is made on samples of cylindrical shape, which are micro-machined by focused ion beam (FIB) microscopy. This pre-defined geometry allows the exclusion of secondary, non-active materials from the electrochemically active material as well as the removal of any vagueness owing from the irregular geometry of particles. The experimental results are also used to validate a proposed coupled electrochemical and mechanical model for determining the stress–strain state of active electrode material during electrochemical cycling. The results produced using this model correlate strongly with the experimental data. The combined results reveal the key effects of the geometry, kinetics, and mechanics of electrode materials on the stress–strain state, which acts as a barometer of the structural stability of a material.
We report the electrochemical synthesis of iron phosphide films used as anodes of lithium secondary batteries. The phosphorus content in the film was increased to a level almost equal to that of Fe (corresponding to a FeP y composition with 0.85< y <0.91) through the selective electrochemical dissolution of Fe and Fe-rich phase from the electroplated film. The as-deposited film exhibited a dense structure characterised by numerous submicron-sized nodules in contact with each other, and maintained its overall mechanical integrity even after the selective dissolution. The as-deposited and the selectively etched films with high P content were tested as anodes of lithium secondary batteries. The performance of the selectively etched films far exceeded that of the as-prepared films. In particular, a 500-nm-thick film maintained a reversible discharge capacity greater than 420mAhg−1 after 30 cycles. No specific physical damage was observed in the film after the cycling tests.
Na-rich NaxFeFe(CN)6 (NFF) in terms of low cost and high theoretical capacity has been considered to be a potential cathode material for aqueous sodium ion batteries (SIBs). However, low sodium content, poor Columbic efficiency (CE) and rapid capacity degradation impede their practical application. Herein, the effect of low-level Ni doping in NFF as cathode materials in 1 M NaNO3 electrolyte has been investigated, which were synthesized via a citrate-assisted co-precipitation route. NFF substituted with 23% Ni2+ exhibited the best electrochemical behaviors, which delivers a discharge capacity of 105.9 mAh g−1 at 200 mA g−1 and 73.1% capacity retention over 1000 cycles with an average CE of 99.8% at 1000 mA g−1. A reversible capacity of 55.5 mAh g−1 can be obtained even at a high current density of 2000 mA g−1. The Ni substitution strategy was evidenced to be a scalable method to prepare promising cathode materials with excellent cycling stability for high-performance aqueous SIBs.
Technology shifts are lethal to many manufacturing companies. Previous research indicates that this is not purely a problem of technological innovation, but is also closely related to the inertia of business models and business model innovation. This paper inquires into the dynamics of this intersection between technology and business models. Anchored in a case study in the automotive industry, it reveals how a potential technology shift constitutes a business model dilemma for firms leading in the existing technology. The paper illustrates why technology shifts are so difficult to master and contributes to theory by suggesting that managing technology shifts does not require either technology or service innovation in order to create a viable business model, but instead a compound of both. Furthermore, the paper applies a business model perspective to illustrate the explanatory power of analyzing the challenges of technology shifts faced by incumbent firms.
A carbon-coated nanocrystalline LiFePO4 cathode material was synthesized by pyrolysis of polyacrylate precursor containing Li+, Fe3+ and PO4 −. The powder X-ray diffraction (XRD) and high-resolution TEM micrographs revealed that the LiFePO4/C composite as prepared has a core-shell structure with pure olivine LiFePO4 crystallites as cores and intimate carbon coating as a shell layer. Between the composite particulates, there exists a carbon matrix binding the nanocrystallites together into micrometer particles. The electrochemical measurements demonstrated that the LiFePO4/C composite with an appropriate carbon content can deliver a very high discharge capacity of 157mAhg−1 (>92% of the theoretical capacity of LiFePO4) with 95% of its initial capacity after 30 cycles. Since this preparation method uses less costly materials and operates in mild synthetic conditions, it may provide a feasible way for industrial production of the LiFePO4/C cathode materials for the lithium-ion batteries.
Constant current and pulsed current electrodeposition of aluminium nano-rods, for use as three-dimensional (3D) Li-ion micro-battery current collectors, have been studied using an ionic liquid electrolyte (1-ethyl-3-methylimidazolium chloride/aluminium chloride) and a template consisting of a commercial alumina membrane. It is shown that the homogeneity of the height of the rods can be improved significantly by inclusion of a short (i.e. 50ms) potential pulse prior to the controlled current deposition step. The latter potential step increased the number of aluminium nuclei on the aluminium substrate and the best results were obtained for a potential of −0.9V vs. Al/Al3+. The obtained nanostructured surfaces, which were characterized using electron microscopy and X-ray diffraction, consisted of parallel aligned aluminium nano-rods homogeneously distributed over the entire surface of the substrate. A narrower height distribution for the rods was obtained using a pulsed galvanostatic approach then when using a constant current, most likely due to the less favourable diffusion conditions in the latter case. The results also indicate that depletion and iR drop effects within the nano-pores result in a more homogeneous height distribution. It is concluded that the height distribution of the nano-rods is controlled by a combination of the nucleation probability in each pore at the start of the experiment, and the homogeneity of the diameters of the pores within the commercial alumina membranes employed as the electrodeposition template.
Electrochemical models of lithium-ion batteries have been increasingly considered for online state of health estimation. These models can more accurately predict cell performance than traditional circuit models and can better relate physical degradation mechanisms to changes in model parameters. However, examples of state of health estimation algorithms that are validated with experimental data are scarce in the literature, particularly for cells with a composite electrode. The individual electrode active materials in a composite electrode may degrade at different rates and according to different physical mechanisms, and online estimation of this degradation facilitates more robust knowledge of how battery performance changes over its life. In this paper we use a reduced-order electrochemical model for a composite LiMn2O4-LiNi1/3Mn1/3 Co1/3O2 (LMO-NMC) electrode cell for online estimation of active material loss. Experimental data collected from composite electrode half cells that were aged under constant current cycling are used in an extended Kalman filter to estimate model parameters associated with loss of each active material. The capacity loss predicted by the online estimates agrees well with the measured capacity loss. Additionally, a differential capacity analysis demonstrates that active materials lose capacity at a similar rate, the same conclusion obtained from the online estimation algorithm.
An Ag2O/Ag electrode was prepared through the electrochemical oxidation of sterling silver. This electrode was used as a cathodic electron acceptor in a microbial fuel cell (MFC). The Ag2O/Ag electrode was characterized by scanning electron microscopy, X-ray powder diffraction and linear sweep voltammetry. The maximum voltage output of the MFC with the Ag2O/Ag cathode was maintained at between 0.47 and 0.5 V in 100 cycles, indicating the good regenerative capacity of the Ag2O/Ag electrode. The overpotential loss for silver oxide was 0.021–0.006 V, and the maximum power output, open circuit potential and short circuit current of the MFC were 1.796 W m−3, 0.559 V and 9.3375 A m−3, respectively. The energy required for electrochemical reoxidation ranged from 40% to 55% of the energy produced by the MFC. Results indicated that the Ag2O/Ag electrode could be used as a cathodic electron acceptor in MFCs with excellent stability.
Lithium-ion battery performance is affected by cut surface quality during the electrodes' cutting process. Currently, die cutting and rotary knife slitting have been used to cut prismatic and cylindrical electrodes, respectively. Both techniques, which require expensive tooling that wear out over time, result in process instability and poor cut quality. These will cause an internal short circuit and significant heat generation in the cells. Laser cutting, proved and widely utilized in the industry, can solve the abovementioned problems by improving cut surface quality due to many advantages, such as no tool wear, high energy concentration, fast processing speed, very narrow Heat Affected Zone, applicability to nearly all materials, and flexibility of laser power. Investigating underlying physical phenomena with numerical analysis provides significant advantages to fully utilize the remote laser cutting of electrodes for lithium-ion batteries. In this paper, a mathematical model of three-dimensional self-consistent remote laser cutting is presented for anode (graphite-coated copper) of lithium-ion batteries. Computational and experimental results, obtained by using laser power of 450 W and scanning speed of 5 m s−1, show a two-step melt pool geometry and copper composition increase on the material interface.
Fuel cell hybrid vehicles offer a high-efficiency and low-emission substitute for their internal combustion engine counterparts. The hybridization significantly improves the fuel economy of the vehicle; however, exploiting the hybridization requires a well-designed power management strategy that optimally shares the power demand between the power sources. This paper deals with the optimization of power management strategy of a fuel cell/battery hybrid vehicle, both off-line and in real-time. A new formulation of the optimization problem for the real-time strategy is presented. The new approach allows the optimization of the controller over a set of driving cycles at once, which improves the robustness of the designed strategy. The real-time optimization is applied to two forms of real-time controllers: a PI controller based on Pontryagin's Minimum Principle with three parameters and a fuzzy controller with ten parameters. The results show that the PI controller can outperform the fuzzy controller, even though it has fewer parameters. The real-time controllers are designed by simulation and then validated by experiment.
Spatially-confined electrochemical reactions are firstly realized in a highly dense nanocomposite anode for high performance lithium ion batteries. The spatially-confined lithiation–delithiation effectively avoids inter-cluster migration and perfectly retains full structural integrity. Large reversible capacity, high rate capability and superior cycling stability are achieved simultaneously. This spatially-confined lithiation–delithiation offers novel insight to enhance cycling performance of high capacity anode materials.
During bioleaching of Cobalt from waste lithium-ion batteries, the biooxidation activity of acidophilic bacteria is inhibited by a high concentration of Co ion in the liquid phase. However, the mechanism for Co2+ toxicity to acidophilic bacteria has not been fully elucidated. In this study, the effects of Co2+ concentration on the biooxidation activity for Fe2+, intracellular reactive oxygen species (ROS) level and antioxidant defense systems in a mixed-culture of acidophilic bacteria (MCAB) were investigated. The results showed that the biooxidation activity of the MCAB was inhibited by Co2+. Furthermore, it was indicated that the intracellular ROS contents of the MCAB under conditions of 0.4 M and 0.6 M Co2+ were 2.60 and 3.34 times higher than that under the condition of 0 M Co2+. The increase in intracellular malondialdehyde content indicated that the oxidative damage was induced by Co2+. Moreover, the antioxidant systems in MCAB were affected by Co2+. It was observed that the Co2+ exposure increased the catalase and glutathione peroxidase activities while reducing the superoxide dismutase activity and the intracellular glutathione (GSH) content. It was found that an exogenous GSH supplementation eliminated excess intracellular ROS and improved the biooxidation activity of the MCAB.
A flexible three-dimensional carbon cloth/carbon fibers/NiCo2O4 composite electrode is prepared via a two step method: first growth carbon fibers on flexible carbon cloth; second coating NiCo2O4 on the carbon cloth/carbon fibers composite. The carbon cloth guarantees the flexibility of electrodes. The three-dimensional carbon cloth/carbon fibers conductive network enhances the ionic transportation property and offer high conductivity. The ultrathin and porous NiCo2O4 nanosheet layers contribute high faradic capacity. The hierarchically porous electrode structure further facilitates to shorten the electrolyte diffusion path. When used as electrodes for electrochemical capacitor, the composite electrode exhibits superior energy storage performances with high specific capacitance of 1221Fg−1 at 1Ag−1, outstanding cycle stability (81% capacitance retention after 3000 cycles) and excellent flexibility. To further investigate the performances of the carbon cloth/carbon fibers/NiCo2O4 composite electrode, we assemble an all-solid-state symmetric electrochemical capacitors device using identical carbon cloth/carbon fibers/NiCo2O4 composite as electrodes. The assembled device delivers a high energy density of 27.2Whkg−1 at a power density of 1.46kWkg−1 and outstanding cycling stability with 91% capacitance retention after 2000 cycles. The combination of excellent flexibility and outstanding energy storage performance of the device will help to pave the way to wearable electronics and devices.
Electrochemical capacitors, based on the double-layer capacitance of high specific-area C materials, are attracting major fundamental and technological interest as highly reversible, electrical charge-storage and delivery devices, capable of being operated at high power-densities. A variety of applications have been described in the literature, e.g. for cold-start vehicle assist, in hybrid load-leveling configurations with batteries, fuel-cells, as well as directly with internal combustion engines. Additionally, high capacitance C electrodes have been usefully employed as anodes coupled with battery-type cathodes, e.g. Pb/PbO2, in so-called “asymmetric” capacitor cells. On account of these perceived various applications, requirements for performance evaluation must be developed in systematic and complementary ways. In the present paper, we examine experimentally the following test procedures as exemplified by application to an high specific-area (ca. 2500m2 g−1) woven C-cloth capacitor electrode material: (i) evaluation of the specific capacitances as a function of charge/discharge rates employing cyclic-voltammetry and dc charging curves; (ii) as in (i), examination of reversibility and energy-efficiency as a function of electrolyte (H2SO4) concentration, i.e. conductivity; (iii) interpretation of effects in (i) and (ii) in terms of distributed resistance and capacitance in the porous C matrix according to the de Levie model; (iv) interpretation of data obtained in (i) in terms of Ragone plots which, for capacitor devices, require special treatment owing to the fundamental dependence of electrode- (or device) potential on state of discharge; (v) interpretation of self-discharge (SD) kinetics in terms of porous-electrode structure. Performance data for the C-electrode are given for capacitative charging up to high “C-rates”, extension of operational voltage windows and for SD behaviour.
High pressure–high temperature (HP/HT) methods are utilized to introduce structural modifications in the layered lithium transition metal oxides LiCoO2 and Li[NixLi1/3−2x/3Mn2/3−x/3]O2 where x = 0.25 and 0.5. The electrochemical property to structure relationship is investigated combining computational and experimental methods. Both methods agree that the substitution of transition metal ions with Li ions in the layered structure affects the compressibility of the materials. We have identified that following high pressure and high temperature treatment up to 8.0 GPa, LiCoO2 did not show drastic structural changes, and accordingly the electrochemical properties of the high pressure treated LiCoO2 remain almost identical to the pristine sample. The high pressure treatment of LiNi0.5Mn0.5O2 (x = 0.5) caused structural modifications that decreased the layered characteristics of the material inhibiting its electrochemical lithium intercalation. For Li[Li1/6Ni1/4Mn7/12]O2 more drastic structural modifications are observed following high pressure treatment, including the formation of a second layered phase with increased Li/Ni mixing and a contracted c/a lattice parameter ratio. The post-treated Li[Li1/6Ni1/4Mn7/12]O2 samples display a good electrochemical response, with clear differences compared to the pristine material in the 4.5 voltage region. Pristine and post-treated Li[Li1/6Ni1/4Mn7/12]O2 deliver capacities upon cycling near 200 mA h g−1, even though additional structural modifications are observed in the post-treated material following electrochemical cycling. The results presented underline the flexibility of the structure of Li[Li1/6Ni1/4Mn7/12]O2; a material able to undergo large structural variations without significant negative impacts on the electrochemical performance as seen in LiNi0.5Mn0.5O2. In that sense, the Li excess materials are superior to LiNi0.5Mn0.5O2, whose electrochemical characteristics are very sensitive to structural modifications.
Knotwood or bark extracts prepared from 30 species of hard and soft wood trees as well as selected pure compounds (lignans, stilbenes and flavonoids) were assayed for their antimicrobial activity against a battery of both gram positive and negative bacteria, yeasts, and filamentous fungi (Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Lactobacillus plantarum, Escherichia coli, Salmonella infantis, Pseudomonas fluorescens, Candida albicans, Saccharomyces cerevisiae, Aspergillus fumigatus and Penicillium brevicompactum). By far the most consistent antibacterial and antifungal properties were associated with extracts of Pinus species. These extracts showed also cytotoxicity against a mouse hepatoma cell line. Both antimicrobial and cytotoxic properties correlated with the stilbene content of the extracts. Purified stilbenes showed the most consistent antimicrobial and cytotoxic activities, while purified lignans had marginal effects, only. The results suggest that stilbenes account both for the antimicrobial and cytotoxic properties of Pinus knotwood extracts.
In this work, cobalt from spent cellular telephone Li-ion batteries was recovered by electrochemical techniques. According to X-ray diffraction results, the composition of the positive electrode is LiCoO2, Co3O4, C, and Al. The largest charge efficiency found was 96.90% at pH 5.40, potential applied of −1.00V and a charge density of 10.0°Ccm−2. The charge efficiency in the electrochemical recycling of cobalt decreases with the decrease in pH. The energy dispersive X-ray analysis (EDX) measurements of the electrodeposits showed that the surface is constituted of 100% cobalt. Scanning electron microscopy (SEM) showed a three-dimensional nucleus growth. The application of nucleation models to the initial stages of electrodeposit growth shows that at pH 5.40 electrodeposition happens with progressive nucleation. With the decrease in pH to 2.70, nucleation becomes instantaneous.