batterydata/paper-abstracts huggingface dataset:
Pt-based bimetallic alloys have attracted intensive interests as highly efficient and stable heterogeneous catalysts for fuel cell applications, and searching flexible free-standing nanomembranes has been on the research focus because of their promising applications in catalysis, nanoelectronics, batteries, and sensing. Herein, a flexible free-standing paper composed of FePt alloy nanoparticles on nitrogen-doped paper (FePt–NG paper) has been developed as integrated electrode towards electrocatalytic oxidation of formic acid. It is found that, N doping is beneficial for the well dispersion of FePt nanoparticles on NG paper. The synergistic effect between Fe and Pt, as well as N doping effect simultaneously assures the improved catalytic activity of FePt–NG paper, making it the promising flexible electrode for application in fuel cell system. Moreover, the synthesis strategy could be used for the construction of other free-standing electrode towards catalysis, sensing, and battery applications.
Transcutaneous electric acupoint stimulation (TEAS) avoids the use of needles, and instead delivers a mild electric current at traditional acupoints. This technique has been used for treating heroin addiction, but has not been systematically tested for other drugs of abuse. This study aims to investigate the effects of TEAS on drug addiction.
In this work, we perform a comprehensive study of five phenomena of LiNi1-2xCoxMnxO2 (NCM) (x = 0–1/3) cathodes at the end of charge (phase reaction, crack propagation, Li-Ni exchange, phase transition, and oxygen evolution), using first-principle calculations within the DFT + U framework. Based on our results, we have located the obstacles toward unity efficiency and revealed that the degradation strongly depends on the Ni concentration and the depth of charge. The threshold capacities for degradation of LiyNi1-2xCoxMnxO2 are 130–140 mA·hg−1 (y < 0.5) for 1/4 ≤ x = 1/3 (33.33–50% of Ni), and 200–210 mA·hg−1 (y < 0.25) for 0 ≤ x = 1/4 (50–100% of Ni), respectively. For 1/4 ≤ x = 1/3, our results show that the origin of the degradation is the oxidation of O2−, which is the result of the pining of O-p and Ni-d bands at the valence band edge. For 0 ≤ x = 1/4, lattice distortion and Li-Ni exchange are the mechanisms responsible for the degradation of the cathode material, leading to severe structural instabilities in the Ni-rich region (x = 0.1). Our findings will help to rationally design NCM cathode materials with high-energy density, also providing possible solution mechanisms to the degradation factors, such as doping, coating or novel nanostructures, like core-shell or concentration gradient cathodes.
A novel conducting polymer of polynaphthidine, poly(NAP), was synthesized electrochemically by direct anodic oxidation of naphthidine in aqueous media. The yield of the electropolymerization reaction depends on the temperature and pH of the solution. It was possible to differentiate two working regions: I (for pH<0.5 and all temperatures) where the film yield tends to zero and II (for approximately 2.0<pH<2.8 and temperatures >15°C) where the film production is maximum. Therefore, the naphthidine electrooxidation mechanism was studied under experimental conditions of region I by cyclic (CV) and square wave voltammetries (SWV) as well as by controlled potential electrolysis. The experimental conditions of region II were chosen to obtain the poly(NAP). The electrochemical response of the film was investigated in pH 1 HClO4 +0.1M NaClO4 electrolyte solution by CV and SWV. A plot of I p,n/f vs. f from SW voltammograms showed the so-called “quasi-reversible maximum”. Formal potential, formal rate constant and anodic transfer coefficient for the surface redox process were also evaluated from the SWV. The poly(NAP) is insoluble in common organic solvents and shows electrochromic behaviour. Its probable structure was determined by FTIR spectroscopy.
This work reports the results of a systematic study on the effect of Co as substituent for Ni on several physical and electrochemical properties of LaNi4.7−x Sn0.3Co x metal hydride alloys, where 0≤x≤0.7. These included the unit cell lattice parameters measured using X-ray diffraction (XRD) and the electronic properties obtained using X-ray absorption spectroscopy (XAS). In general, the presence of cobalt in the alloys causes a decrease on the hydrogen equilibrium pressure and on the rate of capacity decay, and an increase in the cycle life and on the alloy activation time. A negligible effect of Co is observed in the maximum charge storage capacity and on the catalytic activity with respect to the hydrogen oxidation reaction (HOR).
Optimal investment in battery energy storage systems, taking into account degradation, sizing and control, is crucial for the deployment of battery storage, of which providing frequency control is one of the major applications. In this paper, we present a holistic, data-driven framework to determine the optimal investment, size and controller of a battery storage system providing frequency control. We optimised the controller towards minimum degradation and electricity costs over its lifetime, while ensuring the delivery of frequency control services compliant with regulatory requirements. We adopted a detailed battery model, considering the dynamics and degradation when exposed to actual frequency data. Further, we used a stochastic optimisation objective while constraining the probability on unavailability to deliver the frequency control service. Through a thorough analysis, we were able to decrease the amount of data needed and thereby decrease the execution time while keeping the approximation error within limits. Using the proposed framework, we performed a techno-economic analysis of a battery providing 1 MW capacity in the German primary frequency control market. Results showed that a battery rated at 1.6 MW, 1.6 MWh has the highest net present value, yet this configuration is only profitable if costs are low enough or in case future frequency control prices do not decline too much. It transpires that calendar ageing drives battery degradation, whereas cycle ageing has less impact.
A facile solvothermal way to immobilize nanocrystalline LiMn2O4 on the surface of graphene nanosheets is developed to improve the functionality of lithium manganate as lithium intercalation electrode. A solvothermal treatment for the colloidal mixture of graphene oxide (GO) nanosheets and LiMn2O4 nanocrystals gives rise not only to the reduction of GO to reduced graphene oxide (RGO) but also to the immobilization of lithium manganate nanoparticles on the surface of RGO nanosheets. According to powder X-ray diffraction and electron microscopic analyses, the crystal structure and morphology of spinel lithium manganate remain intact upon the composite formation with the RGO nanosheets. The application of larger aldehyde molecule as a reductant leads to the increase of crystallinity and the lowering of Mn oxidation state for the pristine LiMn2O4 and its nanocomposite with the RGO nanosheets. The present LiMn2O4–RGO nanocomposites display promising cathode performances for lithium rechargeable batteries, which are much superior to those of the pristine LiMn2O4 nanocrystals. The observed enhancement of electrode performance upon the composite formation with the RGO nanosheets is attributable both to the improvement of the surface ion transport of nanocrystalline lithium manganate and to the increase of electrical conductivity. The present experimental findings demonstrate that the solvothermal treatment with RGO nanosheets provides an effective way of improving the electrochemical activity of nanocrystalline lithium metal oxides.
High lithium ion conducting 70Li2S·(30− x)P2S5·xP2S3 (mol%) glasses and glass–ceramics were prepared by the mechanical milling method. Glasses were obtained in the composition range of 0≦ x ≦10. The substitution of P2S3 for P2S5 promoted the formation of the P2S6 4− units in the glasses. The conductivity of the glass increased with an increase in P2S3 contents up to 5mol% and the glass with 5mol% of P2S3 showed the conductivity of 1×10−4 Scm−1 at room temperature. In the case of glass–ceramics, the conductivity increased with an increase in P2S3 contents up to 1mol%, and the superionic conducting Li7P3S11 crystal was precipitated in the glass–ceramic. The glass–ceramic with 1mol% of P2S3 showed the highest conductivity of 3.9×10−3 Scm−1 at room temperature.
In this paper, we report a modeling methodology on the transient behaviors of a lithium-ion battery (LIB) during dynamic cycling. To account for the short time effects of current pulses and rest periods, the nonfaradaic component of the current density transferred through the separator between the positive and negative electrodes is included based on the lumped double-layer capacitance. Two-dimensional modeling is performed to predict the transient behaviors of an LIB cell during dynamic cycling. To validate the modeling approach presented in this work, modeling results for the variations in cell voltage and two-dimensional temperature distribution of the LIB cell as a function of time are compared with the experimental data for constant-current discharge and charge cycles and the Heavy Duty Urban Dynamometer Driving Schedule cycles. The transient behaviors obtained from the modeling agree well with the experimental measurements.
The interfacial capacitance of large area, single layer graphene was directly measured with electrolyte accessing both sides of the graphene sheet. PMMA and photoresist patterns were used as supports to suspend the CVD grown graphene in electrolyte during electrochemical testing. Both one and two sides of single layer graphene films were measured and compared. The results show that the area normalized charge that can be stored simultaneously on both sides is significantly lower than could be stored on just one side of single layer graphene, consistent with charge storage having a quantum capacitance component. These measurements are also consistent with the specific capacitance of graphene materials as previously measured in supercapacitor cells and provide a basis for the further understanding and development of graphene based materials for electrical energy storage.
Considering inherent large structural deterioration of conversion-type anode materials during repeated sodiation/desodiation process, the ingenious integration of both nanostructure engineering and chemical hybridization is highly desirable and challenging. Here, ultrafine CoS nanoparticles embedded in porous carbon nanorods (denoted as 7-CoS/C) were facilely fabricated via simultaneous in-situ carbonization and sulfidation of Co-metal organic frameworks (Co-MOF) and have been applied as anode materials for sodium-ion batteries (SIBs). Benefiting from the advantageous embedding architecture between the nanoparticles and porous nanorods, the 7-CoS/C delivers long-term cycling stability (542mAhg−1 after 2000 cycles with a capacity retention of 91.4% at 1Ag−1) and excellent rate performance (discharge capacities of 510mAhg−1 at 5Ag−1 and 356mAhg−1 even at 40Ag−1), which is proved to be characterized of partial pseudocapacitive behaviors during the sodiation/desodiation process. In addition, Na3V2(PO4)3/7-CoS/C full cell with excessive amount of Na3V2(PO4)3 has been assembled and exhibits a capacity of 352mAhg−1 at 0.5Ag−1. This meaningful approach can be extended to build embedded porous structure of other hybrid composites for next-generation energy-storage technology.
To address the corrosion and dendrite issues of lithium metal anodes, a protective layer was ex-situ constructed by P4S10 modification. It was determined by X-ray photoelectron spectroscopy and Raman spectra that the main constituents of the protective layer were P4S10, Li3PS4 and other Li x P y S z type derivatives. The protective layer was proved to be effective to stabilize the interphase of lithium metal. With the modified Li anodes, symmetric cells could deliver stable Li plating/stripping for 16000 h; Li–S batteries exhibited a specific capacity of 520 mA h g−1 after 200 cycles at 1000 mA g−1 with average Coulombic efficiency of 97.9%. Therefore, introducing Li x P y S z based layer to protect Li anode provides a new strategy for the improvement of Li metal batteries.
MnFe2O4/reduced graphene oxide nanocomposite (MnFe2O4/rGO) has been synthesized via a green reduction-coprecipitation method for the first time, which involved in situ reduction of GO in presence of Fe2+ and the ensuing coprecipitation of Fe3+ and Mn2+ onto the surface of rGO. The resultant MnFe2O4/rGO was then employed as the precursor to fabricate LiMn1/3Fe2/3PO4/reduced graphene oxide/carbon composite (LiMn1/3Fe2/3PO4/rGO/C) cathode material for Li-ion batteries. The composite consists of homogeneous Mn-Fe distributed LiMn1/3Fe2/3PO4 with its primary particles (∼200nm) covered and connected by both pyrolytic carbon and rGO sheets, which could prevent the aggregation of the particles as well as construct an interconnected conductive network for rapid transmission of electrons during charging and discharging process. The fabricated LiMn1/3Fe2/3PO4/rGO/C can deliver a discharge capacity of 94.8mAhg−1 even at the high rate of 20C, and shows a capacity decay rate of only 6.25% after 900 long-term charge-discharge cycles. Moreover, the proposed synthesis strategy can also be applied to prepare other graphene-decorated multi-component cathode/anode materials for the Li-ion batteries.
Understanding the degradation mechanism of Lithium-ion batteries (LIBs) is critical in developing high-performance LIBs, and the investigation of their electrical conductivity evolution during cycling can lead to a better understanding of the degradation mechanism of the cathode materials for Li-ion batteries (LIBs). Here, we studied the evolution of the electrical conductivity of LiNi0.8Co0.15Al0.05O2 (NCA) particles for LIB cathodes using scanning spreading resistance microscopy (SSRM). After 300 charge/discharge cycles, stepwise-increasing resistance distributions toward the centers of the secondary particles are observed. These distributions correspond to the degenerated granular structures of the secondary particles caused by the formation of microcracks. In addition, the correlation between the electrical conductivity and microstructure of the NCA cathode is established to explain the observed decay of the NCA discharge capacity. Our findings can provide an insight into the debatable degradation mechanism of LIB cathode materials such as NCA and NMC (LiNixMnyCozO2, x + y + z = 1).
Herein, a new nanocomposite was synthesized via in-situ growth of Fe3O4 nanoparticles on MXene Ti3C2 multilayer to improve the electrochemical performance of anodes by integrating the merits of transition metal oxide and Ti3C2, where further surface modification of Fe3O4@Ti3C2 nanocomposites by carbon coating was introduced here. The nanocomposites exhibited excellent electrochemical performance in Li-ion storage when used as the anode materials, which benefited from the combination of the high capacity of magnetite and favorable electrical conductivity of Ti3C2. The optimized Fe3O4@Ti3C2-2.5 (a mass ratio of 1.1) showed a high reversible capacity of 342.9 mAh·g−1 at 1C, which exceeded the theoretical capacity of bare Ti3C2 monolayer (320 mAh·g−1), and an impressive rate reversibility. TEM presented that the carbon layers were homogeneously coated on the surface of nanocomposites with a thickness of approximately 1 nm. The electrochemical measurement showed that C-coated Fe3O4@Ti3C2-2.5 presented enhanced cycling performance (382.9 mAh·g−1 at 1C and 236.7 mAh·g−1 at 5C) and cycling stability. This work presents a promising route for preparation of transition metal oxides@MXene nanocomposites as well as further surface modification for advanced Li-ion storage.
Rejects from selective collection are municipal solid waste (MSW) not used for recycling and are, therefore, destined for the landfill in Brazil. Knowledge of the composition and generation of this waste is important for strategically planning public policies that minimize its generation and its negative environmental impacts. However, this portion of MSW is not very well known. Therefore, the aim of this study was to analyze the rejects from the sorting process of the selective waste collection in the municipality of Blumenau, in the State of Santa Catarina, southern Brazil. The studied rejects came from the largest cooperative in the city, and its composition was sorted into 17 categories of 101 samples over the course of one year, with a total of 3893 kg of analyzed rejects. The waste collected by the selective collection of the municipality was evaluated monthly to determine which part of this quantity became rejects and to determine the composition and seasonality of these rejects. The study found that 30.5% of the waste sorted by the cooperative was rejected. Among these rejects, the presence of materials that could be marketed by the cooperative was verified. Hazardous and/or legally prohibited waste were also identified, as were organics, construction and demolition waste, health care waste, electronics, textiles, footwear, batteries, and bulbs. Seasonal analysis indicated a concerning constant generation of health care waste. Aside from that, there was an increase in the generation of waste from electrical and electronic equipment (EEE) during the Christmas period, when a large part of the population discards their EEE. This information is important for the enforcement of the MSW management structure as well as for educational campaigns aimed at the correct separation of waste that should be sent for selective collection.
The K2FeO4/TiB2 battery has a significant advantage of battery capacity due to their multi-electron discharge reaction both of the cathode K2FeO4 (3e−) and the anode TiB2 (6e−). However, the more positive reduction potential of TiB2 anode results in a lower discharge voltage plateau of K2FeO4/TiB2 battery, compared with the K2FeO4/Zn battery. The simple modification of Fe(VI) cathode with CuO additive was used to improve the cathode reduction kinetics and decrease the polarization potential in the discharge process. Another electrocatalysis media RuO2 with excellent electric conductivity is used as additive in K2FeO4 cathode to demonstrate which effect is more important for the discharge voltage plateau, electrocatalysis or electron conductivity of additives. The results show that the 5% CuO additive modified K2FeO4/TiB2 battery exhibits an enhanced discharge voltage plateau (1.5V) and a higher cathode specific capacity (327mAh/g). The advanced discharge voltage plateau can be due to the electrocatalysis of additives on the electrochemical reduction kinetics of Fe(VI) cathode in the whole discharge process, rather than the good electronic conductivity of additives.
The implementation of mobile health (mHealth) projects in low- and middle-income countries raises high and well-documented expectations among development agencies, policymakers and researchers. By contrast, the expectations of direct and indirect mHealth users are not often examined. In preparation for a proposed intervention in the Nouna Health District, in rural Burkina Faso, this study investigates the expected benefits, challenges and limitations associated with mHealth, approaching these expectations as a form of situated knowledge, inseparable from local conditions, practices and experiences.
In this paper, a novel method to generate electrical energy by converting available mechanical energy from pressure fluctuations of the cerebrospinal fluid within lateral ventricles of the brain is presented. The generated electrical power can be supplied to the neural implants and either eliminate their battery need or extend the battery lifespan. A diaphragm type harvester comprised of piezoelectric material is utilized to convert the pressure fluctuations to electrical energy. The pressure fluctuations cause the diaphragm to bend, and the strained piezoelectric materials generate electricity. In the framework of this study, an energy harvesting structure having a diameter of 2.5 mm was designed and fabricated using microfabrication techniques. A 1:1 model of lateral ventricles was 3D–printed from raw MRI images to characterize the harvester. Experimental results show that a maximum power of 0.62 nW can be generated from the harvester under similar physical conditions in lateral ventricles which corresponds to energy density of 12.6 nW/cm2. Considering the available area within the lateral ventricles and the size of harvesters that can be built using microfabrication techniques it is possible to amplify to power up to 26 nW. As such, the idea of generating electrical energy by making use of pressure fluctuations within brain is demonstrated in this work via the 3D–printed model system.
This paper presents a life-cycle analysis for a new concept in solar thermal power generation. BRRIMS denotes Brayton-cycle, re-heated, recuperated, integrated, modular and storage-equipped. This concept envisages collection temperatures of around 250 °C, thermal storage in pebble beds, thermal-electric conversion in a piston–cylinder engine and air as the heat transfer fluid and working gas of the engine. The analysis applies to the manufacturing phase of the overall power plant and separately to the pebble bed thermal storage component. Three sustainability metrics are included – life-cycle greenhouse gas emissions, cumulative energy demand and energy payback time. On these metrics, the BRRIMS concept has broadly similar results to a conventional parabolic trough plant with molten salt thermal storage.
In this article an economic and environmental study is carried out on PV solar energy installations connected to the Spanish electrical grid system. The study has been performed on installations situated in the city of Zaragoza (with an irradiation value approximately equal to the average value for Spain). Initially, an economical study is performed, proposing different scenarios where different values of interest rate and energy tariffs are considered. The following parameters are used to determine the profitability of a PV installation: the Net Present Value and the Pay-Back Period. Furthermore, the environmental benefits of PV systems connected to the grid have been evaluated. This has been accomplished using the Life Cycle Analysis theory of the systems, calculating the recuperation time of the invested energy, the contamination or emissions avoided and the externality costs. Finally the possible effects of the application of the Kyoto Protocol have been studied.
Battery inconsistency are exacerbated by the resistance of inter-cell connecting plate (RICP) and the input impedance of battery voltage monitoring system (IIBVMS), both of which cannot be eliminated in a battery pack. Experiments show that the inconsistency distribution and SOC deviation in a battery pack is restricted by RICP and IIBVMS. In this paper, a “parallel-series” battery pack model is proposed and validated. The effects of RICP and IIBVMS on SOC deviation are analyzed. Results indicate that RICP causes unevenly current flowing through each in-parallel battery cell, and so the battery cell directly connected to the battery module posts presents the lowest SOC. In order to restrict SOC deviation to an acceptable level, the equivalent relation of the battery inconsistency caused by RICP to the inherent inconsistency is discussed. The reasonable matching RICP is then presented. IIBVMS causes different current leakage in each voltage sampling line. The closer the battery module connects to the positive terminal of a battery pack, the higher leakage current is. The different leakage current in each voltage sampling line exacerbates battery inconsistency and causes different initial SOC for each battery module. The relationship among the leakage current, the input impedance and the number of in-series battery modules are discussed. And an improved schematic diagram of battery module voltage sampling is further presented to lower the leakage current and to solve the sampling time delay caused by the multi-switch.