batterydata/paper-abstracts huggingface dataset:
N,N′-4,4′-diphenylmethane-bismaleimide (BMI) is attempted to enhance the high-voltage performance for lithium-ion batteries. When 0.1% (m/v) BMI is added into the control electrolyte, the high-voltage cycling performance of LiCoO2/Li cells is improved evidently while charging the cell up to 4.5V rather than the conventional 4.2V. Analysis of scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) demonstrate that an interface film forms on the cathode surface from BMI in electrolyte. AC impedance spectra and charge/discharge test were tested after incubation of the charged cell at 60°C. Linear sweep voltammetry (LSV) is used to test the electrochemical stability window of the electrolyte with BMI addition. The results demonstrate that the improvement of high-voltage performance is attributed to the surface film on cathode. In addition, the BMI addition does not cause damage in conventional performance with 4.2V electrochemical window. The BMI-containing electrolyte provides high-voltage cycling performance with 4.5V electrochemical window, making LiCoO2 battery a simple and promising system for applications with high energy density.
In view of the high theoretical specific capacity of 946 mAh/g, Sb2S3 anode materials have been considered as competitive candidates for high performance lithium ion batteries (LIBs). However, pure Sb2S3 usually suffers from inferior cyclicity because of the extremely large volume expansion upon Li+ uptake and release processes when applied as electrode in LIBs. Combining Sb2S3 with carbonaceous materials would reduce the volume change effect and thus maintains high capacity and substantially improves the cycling performance. Herein, ultrafine Sb2S3 nanoparticles embedded in mesoporous hollow carbon spheres (MHCS) are successfully prepared based on a facile hydrothermal method using MHCS as the microreactor for lithium ion storage, which delivers a desirable specific capacity of 745.3 mAh/g at a current density of 100 mA/g after 160 cycles, and displays prominent rating capability. The outstanding electrochemical performance is due to the mesoporous and unique hollow feature of MHCS, which not only facilitates the electron transfer and Li+ diffusion, but also confines the growth of Sb2S3.
Lithium nickelate is an attractive positive electrode material for lithium ion batteries because of its large capacity at ambient temperatures. However, highly delithiated LiNiO2 (e.g. Li0.2NiO2) shows undesirable exothermal heat at 200°C. We found another issue of LiNiO2 in this study, namely poor reversibility at 40°C. To overcome these disadvantages, we introduced cobalt, manganese, and titanium as partial substituents for nickel. Cobalt substitution was effective in improving the reversibility at 40°C. The exothermal decomposition of the delithiated compounds was suppressed by using manganese and titanium as substituents. We found doubly substituted nickelate LiNi0.8Co0.1Ti0.1O2 to be the most promising in terms of large capacity (190 mA h g−1), enhanced high-temperature performance, and improved thermal stability.
Electropolymerization by cyclic voltammetry and chronoamperometry of N-ethylcarbazole (ETCZ) and 3,4-ethylenedioxythiophene (EDOT) was carried out in water–methanol (v/v: 1/3 0.01 M sodium dodecylsulfate (SDS) and 1.25 M perchloric acid on platinum button electrodes. Methanol improves the ethylcarbazole solubility and allows a well defined polymer growth on the working electrode. The SDS makes easier the ETCZ and EDOT electropolymerization. Indeed, the presence of micelles decreases the monomer oxidation potential and induces an acceleration of the polymerization. ETCZ and EDOT have similar monomer oxidation potentials in this medium. Moreover their polymers show a better stability than the polymers obtained without surfactants. Therefore, electropolymerization mixtures of these monomers was carried out with different ratios (v/v, 70/30, 50/50 and 30/70) in order to prepare copolymers and the resulting products were characterized by electrochemistry, IR and UV–visible spectroscopy and SEM.
There has been minimal evidence examining the differences in submaximal aerobic power between children with and without probable developmental coordination disorder (pDCD). This is important as most activities of daily living are performed at submaximal levels. The aim of this study was to examine the oxygen cost of work (VO2) performed during an incremental exercise protocol on a cycle ergometer. Subjects with pDCD (n =63) were matched for age and gender to 63 typically developing controls (12–13 years of age) using a nested case–control design. Motor coordination was assessed using the Movement Assessment Battery for Children. Children with pDCD had significantly lower VO2 peak values relative to controls (35.0 vs. 42.9ml/kg/min, p <0.0001). At the submaximal level, mixed effects modeling demonstrated that, after controlling for relative body fat, and VO2 peak, children with pDCD had consistently greater oxygen cost (VO2 ml/kg/min) compared to controls at any given exercise intensity (p =0.0006). A significant interaction between pDCD and workload indicated that the difference in VO2 at higher workloads is greater than that at lower workloads (p =0.0004). Children with pDCD utilize more oxygen to sustain the same submaximal workload. The implication of these findings is that children with pDCD may experience earlier fatigue than well coordinated individuals when engaging in physical activity.
The vast majority of power/energy generation in our global economy is based on the chemical element carbon, specifically fossil carbon (coal) and hydrocarbon (oil and gas) fuels. Such an economy is not sustainable in the medium- to long-term for two fundamental reasons; first, there exists only a finite amount of fossil fuel, and, second, the carbon dioxide released during the combustion of fossil fuels induces anthropogenic climate change with costly and potentially disastrous consequences. Current energy technologies cannot support both a reduction in carbon dioxide emissions and an ever-expanding global economy. It is now recognized that hydrogen may be one of the leading contenders as a potential solution for a sustainable alternative to fossil fuels, especially for transport and for heat and power generation and energy storage. However, any transition from a carbon-based (fossil fuel) energy system to a hydrogen-based economy involves significant scientific, technological and socio-economic barriers. Our aim is to illustrate the “hydrogen nexus” as a possible connection or link from today's carbon economy to a sustainable energy future centred on hydrogen.
Here a simple design which could be developed for flat redox microbattery array with tunable output power is introduced. The fabrication of a V3+/Fe3+ redox microbattery using the gold compact disk (CD) as the electrode material and employing drilling technique to fabricate band electrodes is reported. The as-fabricated V3+/Fe3+ redox microbattery shows very attractive performance such as rechargeability, very high power and current density, low cost and simplicity of fabrication. Also microbattery arrays could be stacked very easily to achieve proper voltage, current and output power. Polarization and power curves and charge–discharge cycles are obtained to characterize as-fabricated microbatteries.
The problem of minimizing the overall travel time, considering the one spent at charging stations, with the aim to improve the cruising range for Electric Vehicles (EVs) in road networks, is examined in this paper. Since the battery capacity of EVs is limited, it is inevitable for them to stop at charging stations. As they are lacking and the recharging process is time-consuming, an efficient route planning is essential. This paper extends a previously presented approach, i.e., EVRC (Electric Vehicle Route Planning with Recharging). In detail, the solution presented in this work considers a set of factors into account simultaneously and introduces a functional approach that estimates time-optimal routes for road networks with realistic models of charging stops. The key features include the efficient computation of the recharging station’s locations, the battery charging amount under a partial charging scheme, the nonlinear charging functions, and the service time duration at recharging stations. The experimental results highlight that the proposed approach outperforms other similar methods in facing the same problem. The extensive experimental evaluations show that refusing partial charging and neglecting nonlinear charging, as well as servicing time, may generate some infeasible or too costly solutions.
The present work is a numerical study of the transmission properties of a multilayer structure operating at the telecom wavelengths 1.55 and 1.53 μm. The transmission peak is obtained by the periodic alternation of two layers of porous silicon (PS) of different porosities (85 and 75%), separated by a graphene layer. The modification of the graphene Fermi energy (EF) allows the adjustment of the transmission peak wavelength. Fixing Fermi energy to EF = 0.47 eV and EF = 1.525 eV allows to set the working wavelength to 1.55 and 1.53 μm, respectively. Under the variation of the temperature and of the degree of oxidation of the PS, the transmission properties of the structure are altered. We shows that the adjustment of EF makes it possible to correct the shifts in the working frequency induced by these two parameters. The simulation results show that the variation of EF can compensate the variation of the temperature on the interval 293–73 K as well as the variation of the oxidation of the PS up to 10%.
Capacity loss modeling is required for accurate and reliable lifetime evaluation of lithium-ion batteries. The current capacity loss model parameters cannot be identified online. To address this problem, this paper has developed a capacity loss model based on the aging mechanisms of solid electrolyte interface layer growth and active material loss. Experimental results show that capacity loss due to solid electrolyte interface growth is independent of state of charge ranges during cycling, whereas capacity loss due to active material loss depends on the state of charge ranges. A comprehensive aging model is thus developed, combined with the recursive least squares method to identify the model parameters in realtime. In our case studies, the estimation errors of the capacity loss model are within 1% under different state of charge ranges. To avoid the modeling error caused by cell characteristic inconsistencies, model parameters are further updated adaptively based on online data for predicting the accurate lifetime of the specific cell.
We reported the synthesis of large-area manganese oxide nanorods (MONRAs) on carbon fabric and their implementation as flexible supercapacitors. Electrochemical measurements demonstrated that MONRAs exhibited a high capacitance (678Fg−1 at a current density of 0.3Ag−1) with high flexibility and excellent cycle performance (less than 3% capacitance loss after 10,000 cycles). Furthermore, the fabricated solid-state devices based on these MONRAs electrodes exhibited good electrochemical performance and could power a red LED well for about 5min after charging at 0.5mAcm−2 for 30s, with an energy utilization efficiency of about 80%. These findings show that MONRAs are a kind of very promising electrode material for flexible supercapacitors.
Fast capacity degradation is a significant drawback hindering La–Mg–Ni-based alloys from wide application as anode electrode materials of nickel metal hydride batteries. Herein, the effect of Pr element on the phase structure and cycling stability of La0.8−x PrxMg0.2Ni3.4Al0.1 (x =0, 0.1, 0.2 and 0.3) alloys is investigated. All the alloys contain (La,Mg)2Ni7 and (La,Mg)5Ni19 main phases as well as LaNi5 minor phase. It is found that Pr tends to form [AB5] subunits more than [A2B4] subunits, thus increasing the content of (La,Mg)5Ni19 phase with higher [AB5]/[A2B4] ratio in sacrifice of (La,Mg)2Ni7 phase. The increased (La,Mg)5Ni19 phase network with good structural stability increases the anti-pulverization and anti-amorphization resistance of the alloys. After 100 charge/discharge cycles, part of the superlattice phases in La0.6Mg0.2Ni3.4Al0.1 alloy decomposes into amorphous phase and LaNi5 phase, leading to the decrease in superlattce phase abundance; while little amorphization is observed for La0.6Pr0.2Mg0.2Ni3.4Al0.1 alloy and its phase contents remain almost unchanged. Correspondingly La0.6Pr0.2Mg0.2Ni3.4Al0.1 alloy electrode has a slighter oxidation degree after 100 cycles in alkaline electrolyte and exhibits good electrochemical cycling stability with a discharge capacity of 340mAhg−1 and a cycling stability of 90.7% at the 100th cycle.
Chemical delithiated LixCoO2 (x=1, 0.7, 0.66 and 0.57) has been synthesized by using a strong oxidant, NaS2O8. The structure investigations indicate that all the samples remain with hexagonal cells, which have expansion of c axis during Li extraction. Transmission electron microscopy (TEM) observations revealed the presence of superstructures arising from intercalated Li-ordering corresponding to first-principle calculations. The measurements of the physical properties are also influenced by Li concentration.
Throughout recent years the implementation of nanocarbons into dye-sensitized solar cells (DSSC) has resulted in important breakthroughs. The most relevant of them in this context are (i) the enhancement of charge transport and charge collection in nanocarbon-doped electrodes, (ii) the introduction of nanocarbon interlayers that simultaneously reduce the charge recombination and increase the charge collection efficiency, (iii) the use of nanocarbon-based, iodine-free, solid-state electrolytes featuring excellent diffusion coefficients and catalytic efficiencies, (iv) the use of novel nanocarbon-based hybrid dyes, and (v) the use of nanocarbons towards platinum-free counter electrodes. The first four aforementioned aspects are thoroughly described in this review.
Aqueous alkaline metal-air batteries represent promising energy storage devices when supplied with atmospheric air. However, under this condition, the air electrode shows a very short life time (i.e. 50 h of operation in 5 M LiOH at −10 mA cm−2), mainly due to the precipitation of carbonates inside the electrode porosity. The air electrode can then be protected by an anion exchange membrane on the electrolyte side. In this paper, we demonstrate that the efficiency of this protective membrane depends on the assembly method on the electrode. When a modified poly(epichlorohydrin) (PECH) network is synthesized directly on the electrode, the polymer seeps inside the electrode porosity, and a suitable interface inducing negligible additional polarization in comparison with classical pressure-assembled membranes is obtained. This protected electrode shows improved stability of up to 160 h of operation in 5 M LiOH. This performance is improved to 350 h by adjusting the conductivity and the ionic exchange capacity. Finally, the interest of interpenetrating polymer network (IPN) architecture compared to a single network is confirmed. Indeed, an electrode protected with a PECH/poly(2-hydroxyethyl methacrylate) (PHEMA) IPN is stable for 650 h in 5 M LiOH. In addition, degradation process becomes reversible since the assembly can be regenerated, which is not possible for the bare electrode.
The burden of non-communicable chronic diseases, such as hypertension and diabetes, increases in sub-Saharan Africa. However, the majority of the rural population does still not have access to adequate care. The objective of this study is to examine the effectiveness of integrating care for hypertension and type 2 diabetes by task shifting to non-physician clinician (NPC) facilities in eight rural health districts in Cameroon.
Environmentally friendly and flexible piezoelectric nanogenerators (PENGs) have attracted considerable interest for use in autonomous micro-/nano-systems, wearable electronics, and implantable biomedical devices. Herein, a flexible, lead-free, solution-processable and efficient PENG is demonstrated, based on a highly piezoelectric nanocomposite thin film of barium titanate nanoparticles (BT NPs) embedded into a highly crystalline polyvinylidene fluoride–trifluoroethylene (P(VDF–TrFE)) polymer for charge storage. The nanocomposite PENG (nc-PENG) with high loading of BT NPs up to 40wt% in the nanocomposite can produce output voltage as high as 9.8V and output power density of 13.5µW/cm2 under cyclic bending, comparable to the output of conventional inorganic polycrystalline lead zirconate titanate PENGs. The high performance of these nc-PENGs is primarily attributed to the very high effective piezoelectricity of the highly crystalline P(VDF-TrFE), strengthened by the BT NPs. The nc-PENG was also demonstrated to harvest biomechanical energy from simple body movements and store the generated electricity during mechanical and biomechanical motions in a rechargeable microbattery.
Herein, we reveal the critical role of CrCl3 and the mechanism for the synthesis of magnesium chloride complex (MaCC), an advanced conditioning-free electrolyte for rechargeable magnesium batteries. This involves a catalytic dissolution of Mg metal by nanoscale bimetallic galvanic couples in an ethereal solution: At the initial stage, nanoscale amorphous Cr-rich ‘islands’ form on Mg surface, creating numerous Cr-Mg galvanic couples. These Cr-rich islands act as local cathodic sites due to partial electron transfer from Mg metal substrate. Furthermore, the first-principles calculation shows that Al prefers to bind at Cr-rich regions rather than Mg. These trigger a heterogeneous catalysis for the selective deposition of Al on Cr-rich islands and a dramatic increase in the dissolution rate of Mg metal on the neighboring region. This leads to an ultrahigh Mg2+-to-Al3+ concentration ratio in the resultant solution, a key property of the conditioning-free electrolyte. This study is potentially applicable to many other fields like metal-air batteries and corrosion protection of metals, where a subtle manipulation of passive layer is required.
Attempts to understand the causes of cognitive impairment in obstructive sleep apnea (OSA) are complicated by the overlap among clinical and demographic factors that may impact cognition. The goal of the current study was to isolate the contribution of hypoxemia to cognitive impairment in OSA.
Humanitarian organizations are increasingly incorporating sustainable energy practices into programming. Policies that are clear and coherent need to be put in place so that the private sector can be progressively engaged and energy services can be scaled-up.
Here we construct a novel sodium dual-ion battery (Na-DIB) with a conventional alkyl/alkylene carbonate electrolyte by using reduced-graphene-oxide-coated Na2Ti3O7 (NTO@G) as the anode and coronene, a polycyclic aromatic hydrocarbon (PAH), as the cathode. The coronene//NTO@G configuration delivers a specific energy of 77Whkg−1, based on the total active mass in both electrodes, and excellent cycling stability with 80% capacity retention after 5000 cycles. In addition, this device can work well in a wide range of temperatures from −20 to 40°C. The results demonstrate a proof-of-concept Na-DIB that avoids the challenges of conventional dual-graphite DIBs by utilizing non-graphite intercalation anode and cathode, and a carbonate-based electrolyte without any additives.
Benzodiazepines have a broad spectrum of clinical applications including sedation, anti-anxiety, and anticonvulsive therapy. At the cellular level, benzodiazepines are allosteric modulators of GABAA receptors; they increase the efficacy of inhibition in neuronal networks by prolonging the duration of inhibitory postsynaptic potentials. This mechanism of action predicts that benzodiazepines reduce the frequency of inhibition-driven network oscillations, consistent with observations from human and animal EEG. However, most of existing data are restricted to frequency bands below ∼30 Hz. Recent data suggest that faster cortical network rhythms are critically involved in several behavioral and cognitive tasks. We therefore analyzed diazepam effects on a large range of cortical network oscillations in freely moving mice, including theta (4–12 Hz), gamma (40–100 Hz) and fast gamma (120–160 Hz) oscillations. We also investigated diazepam effects over the coupling between theta phase and the amplitude fast oscillations. We report that diazepam causes a global slowing of oscillatory activity in all frequency domains. Oscillation power was changed differently for each frequency domain, with characteristic differences between active wakefulness, slow-wave sleep and REM sleep. Cross-frequency coupling strength, in contrast, was mostly unaffected by diazepam. Such state- and frequency-dependent actions of benzodiazepines on cortical network oscillations may be relevant for their specific cognitive effects. They also underline the strong interaction between local network oscillations and global brain states.
As lithium-ion batteries (LIBs) find application in new fields, the specific capacity of single LIBs must be enhanced, and the backward-cell problem in battery modules must be solved. Here, Mn3O4 and carbon nanofragment (Mn3O4/CNF) composites are synthesized and shown to have higher capacities than commercial graphite (theoretical capacity of approximately 372mAh·g−1) and hierarchical voltage plateaus. Nanosized Mn3O4 particles are introduced into the CNFs to simultaneously increase the specific capacity and prevent the corresponding LIB modules from over-discharging. The Mn2+-modified CNFs are spray-dried and calcined to form Mn3O4/CNF composites with 1.62%, 3.21%, and 6.74% Mn, which exhibit enhanced reversible specific capacities of 486.1, 609.3, and 539.0mAh·g−1, respectively, at 0.1C after 100 cycles. Furthermore, the additional voltage plateau at 1.2V due to Mn3O4 can help prevent the corresponding LIB modules from over-discharging and metallic lithium deposition on the anode.
Cathode materials prepared by a co-precipitation are 0.3Li2MnO3·0.7LiMn1−x Ni y Co0.1O2 (0.2≤ x ≤0.4) cathode materials with a layered-spinel structure. In the voltage range of 2.0–4.6V, the cathodes show more than one redox reaction peak during its cyclic voltammogram. The Li/0.3Li2MnO3·0.7LiMn1−x Ni y Co0.1O2 (x =0.3, y =0.2) cell shows the initial discharge capacity of about 200mAhg−1. However, when x =0.2 and y =0.1, the cell exhibits a rapid decrease in discharge capacity and poor cycle life.
We consider the problem of optimal energy allocation and lifetime maximization in heterogeneous wireless sensor networks. We construct a probabilistic model for heterogeneous wireless sensor networks where sensors can have different sensing range, different transmission range, different energy consumption for data sensing, and different energy consumption for data transmission, and the stream of data sensed and transmitted from a sensor and the stream of data relayed by a sensor to a base station are all treated as Poisson streams. We derive the probability distribution and the expectation of the number of data transmissions during the lifetime of each sensor and the probability distribution and the expectation of the lifetime of each sensor. In all these analysis, energy consumption of data sensing and data transmission and data relay are all taken into consideration. We develop an algorithm to find an optimal initial energy allocation to the sensors such that the network lifetime in the sense of the identical expected sensor lifetime is maximized. We show how to deal with a large amount of energy budget that may cause excessive computational time by developing accurate closed form approximate expressions of sensor lifetime and network lifetime and optimal initial energy allocation. We derive the expected number of working sensors at any time. Based on such results, we can find the latest time such that the expected number of sensors that are still functioning up to that time is above certain threshold.