batterydata/paper-abstracts huggingface dataset:
Three electrodes—E1 (0.18mgPtcm−2), E2 (0.38mgPtcm−2), E3 (0.4mgPtcm−2 without a gas-diffusion layer)—are fabricated and compared with a commercial product (E-TEK). The performance of the electrodes increases with increase in Pt loading in the catalyst layer. The performance of the E2 electrode is superior to that of E1, E-TEK or E3. Elimination of the diffusion layer between the carbon-cloth substrate and the catalyst layer affects the performance of electrode E3 in particular. The power density shows a similar pattern to current density. The difference in performance between E2 and E-TEK electrodes may be due to the difference in the method of fabrication. Increase in exchange current density results in an increase in efficiency. The curves for E1, E2 and E-TEK electrodes appear to stabilize at constant efficiency, which indicates maximum efficiency at a lower exchange current density, compared with the E2 electrode, which does not approach a steady efficiency even at an exchange current density of 1mAcm−2. This means that the E2 electrode has greater efficiency than E1, E3 or E-TEK electrodes. Voltage and irreversibility curves for the four electrodes meet at different voltage operational limits; namely, 0.48, 0.55, 0.46 and 0.42V at 1.2, 0.85, 0.4 and 0.3mAcm−2, for E-TEK, E2, E1 and E3 electrodes, respectively. Hence, while these electrodes can be operated conveniently, the E2 electrode with a 0.38mgPtcm−2 loading can be operated at optimum conditions of 0.55V and 0.85mAcm−2.
Solar air conditioning system directly driven by stand-alone solar PV is studied. The air conditioning system will suffer from loss of power if the solar PV power generation is not high enough. It requires a proper system design to match the power consumption of air conditioning system with a proper PV size. Six solar air conditioners with different sizes of PV panel and air conditioners were built and tested outdoors to experimentally investigate the running probabilities of air conditioning at various solar irradiations. It is shown that the instantaneous operation probability (OPB) and the runtime fraction (R F ) of the air conditioner are mainly affected by the design parameter r pL (ratio of maximum PV power to load power). The measured OPB is found to be greater than 0.98 at instantaneous solar irradiation I T > 600 W m−2 if r pL > 1.71. R F approaches 1.0 (the air conditioner is run in 100% with solar power) at daily-total solar radiation higher than 13 MJ m−2 day−1, if r pL > 3.
Graphitic materials cannot be applied for the negative electrode of sodium-ion battery because the reversible capacities of graphite are anomalously small. To promote electrochemical sodium-ion intercalation into graphitic materials, the interfacial sodium-ion transfer reaction at the interface between graphitized carbon nanosphere (GCNS) electrode and organic electrolyte solutions was investigated. The interfacial lithium-ion transfer reaction was also evaluated for the comparison to the sodium-ion transfer. From the cyclic voltammograms, both lithium-ion and sodium-ion can reversibly intercalate into/from GCNS in all of the electrolytes used here. In the Nyquist plots, the semi-circles at the high frequency region derived from the Solid Electrolyte Interphase (SEI) resistance and the semi-circles at the middle frequency region owing to the charge-transfer resistance appeared. The activation energies of both lithium-ion and sodium-ion transfer resistances were measured. The values of activation energies of the interfacial lithium-ion transfer suggested that the interfacial lithium-ion transfer was influenced by the interaction between lithium-ion and solvents, anions or SEI. The activation energies of the interfacial sodium-ion transfer were larger than the expected values of interfacial sodium-ion transfer based on the week Lewis acidity of sodium-ion. In addition, the activation energies of interfacial sodium-ion transfer in dilute FEC-based electrolytes were smaller than those in concentrated electrolytes. The activation energies of the interfacial lithium/sodium-ion transfer of CNS-1100 in FEC-based electrolyte solutions were almost the same as those of CNS-2900, indicating that the mechanism of interfacial charge-transfer reaction seemed to be the same for highly graphitized materials and low-graphitized materials each other.
In this study, stoichiometric Cu2S with monoclinic crystal structure with space group P21/c was prepared via spray pyrolysis with followed heat treatment. Its electrochemical properties were investigated after coating on a carbon fiber paper (CFP) current collector and cycling at various cut-off voltages. The reversible stable capacity of about 330mAhg−1 (98% of its theoretical capacity) exhibited by the cell for 20 cycles at 0.1C and slightly dropped to 311mAhg−1 after 50 cycles. At higher 1C rate, a discharge capacity of 280mAhg−1 was retained for 100 cycles with approximately 100% Coulombic efficiency between 1.0-3.0V. While the gradual capacity decrease is observed with the increase of the discharge cut-off voltage to avoid solid electrolyte interface (SEI) formation during the 1st discharge. The cells showed capacities of 307 and 280mAhg−1 after the 5th cycle at 0.1C when cycled between 1.1-3.0V and 1.2-3.0V, respectively, due to the lowered lithium ion diffusion. Ex situ XRD analysis of the recovered electrodes after cycling with near theoretical capacity allowed discussing the actual reaction mechanism of stoichiometric Cu2S with Li+.
This work reports high-performance supercapattery and lithium-ion storage using nanostructured spinel cobalt oxide (Co3O4) generated by modified facile sol-gel process. The formation of spinel Co3O4 was confirmed by materials characterization techniques. Electrochemical studies of the Co3O4 in KOH revealed excellent redox features. The supercapattery device in the form of CR-2032 coin cell consisting of the Co3O4 as positive electrode and reduced graphene-oxide as negative electrode delivered high energy density of 40 Wh kg−1 at power density of 742 W kg−1. In addition, the half-cell in the form of CR-2032 coin cell having the Co3O4 as anode and lithium metal as counter electrode exhibited stabilized lithium storage capacity of 620 mA h g−1 with high Coloumbic efficiency. Glowing of a commercial LED for more than 15 min using the fabricated supercapattery was demonstrated. The nanofeatures of the sol-gel derived Co3O4 led to such excellent charge storage and lithium storage performances.
The lead sulfate crystals formed on the surface of the negative electrodes of lead-acid batteries during discharge gradually grow in size as a result of recrystallization processes. The big PbSO4 crystals have low solubility and are involved but very slightly in the charge process, thus causing progressive sulfation of the negative electrodes on cycling. In order to reduce or suppress this sulfation, the processes of PbSO4 recrystallization should be inhibited. It has been established that, besides lignosulfonates, some organic substances, too, may be used as additives to the negative active material to effectively inhibit the growth of lead sulfate crystals during battery discharge. The research results discussed in the present paper indicate that the aromatic ester compound of carboxylic acid, Benzyl benzoate (C6H5CH2O2CC6H5), has such inhibiting properties. Lead-acid test cells with negative plates containing Benzyl benzoate (BB) have improved cycle life performance, the beneficial effect of the BB additive to NAM being most pronounced at a loading level of 0.3%. Cells with BB added to the electrolyte have also been tested. In this case, the additive exhibits its inhibiting effect on the processes of PbSO4 crystal growth most strongly when added to the electrolyte at concentration levels of 0.3% or 0.5%.
The aim of this paper is to study the long-run cointegrating relationship of TFP in a panel of five large European economies, namely France, Germany, Italy, Spain, and UK. We test whether TFP is determined by the so-called “capital misallocation effects, scale effects, and labor market effects”. By considering aggregate data, over the period 1983–2017, we employ dynamic panel cointegration techniques to identify the long-run component of TFP. We get two main results. First, the interest rate, the real compensation and the real exchange rate have a positive impact on TFP. Then, the incidence of temporary employment (a proxy of labor market flexibility) has a negative effect on TFP. Moreover, for robustness, we run a panel VECM to check for causalities among the variables. Notably, this further excercise confirms the existence of a strong and positive long-run relationship between TFP and prices. We conclude that coordinated policies on the issue of interest rate, exchange rate, labour cost and regulation, may allow to reassemble the productivity slowdown puzzle and strengthen the European economic structure.
A flexible electrode of nickel diselenide/carbon fiber cloth (NiSe2/CFC) is fabricated at room temperature by a simple and efficient electrodeposition method. Owing to NiSe2 character of nanostructure and high conductivity, the as-synthesized electrodes possess perfect pseudocapacitive property with high specific capacitance and excellent rate capability. In three-electrode system, the electrode specific capacitance of the NiSe2/CFC electrode varies from 1058 F g–1 to 996.3 F g–1 at 2 A g–1 to 10 A g–1 respectively, which shows great rate capability. Moreover, the NiSe2 electrode is assembled with an active carbon (AC) electrode to form an asymmetric supercapacitor with an extended potential window of 1.6 V. The asymmetric supercapacitor possesses an excellent energy density 32.7 Wh kg–1 with a power density 800 W kg–1 at the current density of 1 A g–1. The nanosheet array on carbon fiber cloth with high flexibility, specific capacitance and rate capacitance render the NiSe2 to be regarded as the promising material for the high performance superconductor.
A simple, single step and environmentally friendly process is developed for the synthesis of anion exchange membrane (AEM) by simultaneous polymerization and quaternization, unlike the conventional membrane synthesis which consists of separate polymerization and quaternization step. The membrane synthesis is carried out by dissolving polyvinyl chloride (PVC) in cyclohexanone along with 4-vinyl pyridine (4VP) and 1,4-dibromobutane (DBB) in the presence of thermal initiator benzoyl peroxide, followed by film casting to get thin and flexible AEMs. The membrane properties such as ion exchange capacity, ionic conductivity and swelling behaviour are tuned by varying the degree of crosslinking. These AEMs exhibit low vanadium permeability, while retaining good dimensional and chemical stability in an electrolyte solution, making them appropriate candidates for non-aqueous vanadium acetylacetonate redox flow battery (VRFB) applications. The optimized membrane displays ion exchange capacity and ionic conductivity of 2.0 mequiv g−1 and 0.105 mS cm−1, respectively, whereas the efficiency of 91.7%, 95.7% and 87.7% for coulombic, voltage and energy parameter in non-aqueous VRFB, respectively. This study reveals that the non-aqueous VRFB performance is greatly influenced by membrane properties; therefore the optimal control over the membrane properties is advantageous for the improved performance.
Objective To study the biomechanical mechanism of head injuries beaten with sticks, which is common in the battery or assaultive cases. Methods In this study, the Hybrid-III anthropomorphic test device and finite element model (FEM) of the total human model for safety (THUMS) head were used to determine the biomechanical response of head while being beaten with different sticks. Total eight Hybrid-III tests and four finite element simulations were conducted. The contact force, resultant acceleration of head center of gravity, intracranial pressure and von Mises stress were calculated to determine the different biomechanical behavior of head with beaten by different sticks. Results In Hybrid-III tests, the stick in each group demonstrated the similar kinematic behavior under the same loading condition. The peak values of the resultant acceleration for thick iron stick group, thin iron stick group, thick wooden stick group and thin wooden stick group were 203.4 g, 221.1 g, 170.5 g and 122.2 g respectively. In finite element simulations, positive intracranial pressure was initially observed in the frontal comparing with negative intracranial pressure in the contra-coup site. Subsequently the intracranial pressure in the coup site was decreasing toward negative value while the contra-coup intracranial pressure increasing toward positive values. Conclusions The results illustrated that the stiffer and larger the stick was, the higher the von Mises stress, contact force and intracranial pressure were. We believed that the results in the Hybrid-III tests and THUMS head simulations for brain injury beaten with sticks could be reliable and useful for better understanding the injury mechanism.
Understanding the nature of interactions between nanomaterials, such as commercially ubiquitous hematite (α-Fe2O3) nanorhombohedra (N-Rhomb) and biological systems is of critical importance for gaining insight into the practical applicability of nanomaterials. Microglia represent the first line of defense in the central nervous system (CNS) during severe injury or disease such as Parkinson's and Alzheimer's disease as illustrative examples. Hence, to analyze the potential cytotoxic effect of N-Rhomb exposure in the presence of microglia, we have synthesized Rhodamine B (RhB)-labeled α-Fe2O3 N-Rhomb, with lengths of 47 ± 10 nm and widths of 35 ± 8 nm. Internalization of RhB-labeled α-Fe2O3 N-Rhomb by microglia in the mouse brain was observed, and a dose-dependent increase in the cellular iron content as probed by cellular fluorescence was detected in cultured microglia after nanoparticle exposure. The cells maintained clear functional viability, exhibiting little to no cytotoxic effects after 24 and 48 hours at acceptable, physiological concentrations. Importantly, the nanoparticle exposure did not induce microglial cells to produce either tumor necrosis factor alpha (TNFα) or interleukin 1-beta (IL1β), two pro-inflammatory cytokines, nor did exposure stimulate the production of nitrites and reactive oxygen species (ROS), which are common indicators for the onset of inflammation. Finally, we propose that under the conditions of our experiments, i.e. in the presence of RhB labeled-α-Fe2O3 N-Rhomb maintaining concentrations of up to 100 μg mL−1 after 48 hours of incubation, the in vitro and in vivo internalization of RhB-labeled α-Fe2O3 N-Rhomb are likely to be clathrin-dependent, which represents a conventional mechanistic uptake route for most cells. Given the crucial role that microglia play in many neurological disorders, understanding the potential cytotoxic effects of these nanostructures is of fundamental importance if they are to be used in a therapeutic setting.
Today, lithium-ion battery technology is quite mature and dominates in the portable electronics market. However, for many applications, its long-term cycling and storage behaviour needs to be improved. Especially for the stationary energy storage, the lifetime is an important and critical issue which directly enters into cost calculations. Here we show that mechanical damage as a result of the electrochemical cycling can build up and lead to severe degradation. The material under investigation is LiMn1.95Al0.05O4 which fractures upon extended cycling. SEM images of the same locations are made before and after cycling to study crack formation and growth. Crack growth is observed both during lithiation and delithiation. Larger particles are more susceptible to cracking than smaller ones. The number of cracks increases with the number of cycles and the damage exhibits a characteristic shape. Both can be explained by coupled electrochemical-mechanical fatigue. This damage mechanism is inherent to the observed material and is quite likely also present in other materials. It can be suppressed by limiting the particle size in the electrodes.
Nanoscale science and nanotechnology have been demonstrated to have great potential in providing novel and improved solutions to many grand challenges facing agriculture and society today and in the future. This review highlights some of the most promising and important nanotechnology applications in agriculture; and recommends several strategies for advancing the best scientific and technological knowledge presently being examined. In addition, implications for human and environmental health, and technical, financial and capacity-related challenges as they relate to developing countries are identified. Finally, some suggested mechanisms for partnerships and collaborations are also identified and suggested.
Recent advances in micro- and nano-electromechanical systems (MEMS/NEMS) technology have led to a niche industry of diverse small-scale devices that include microsensors, micromachines and drug-delivery systems. For these devices, there is an urgent need to develop Micro Lithium Ion Batteries (MLIBs) with dimensions on the scale 1–10 mm3 enabling on-board power delivery. Unfortunately, power limitations are inherent in planar 2D cells and only the advent of 3D designs and microarchitectures will lead to a real breakthrough in the microbattery technology. During the last few years, many efforts to optimise MLIBs were discussed in literature, both in the planar and 3D configurations. This review highlights the importance of 3D microarchitectured electrodes to fabricate batteries that can be device-integrated with exceptionally high specific power density coupled with exquisite miniaturisation. A wide literature overview is provided and recent advances in manufacturing routes to 3D-MLIBs comprising materials synthesis, device formulation, device testing are herein discussed. The advent of simple, economic and easily scalable fabrication processes such as 3D printing will have a decisive role in the growing field of micropower sources and microdevices.
The coexistence state of two phases (Li4Ti5O12 and lithiated Li7Ti5O12) in spinel lithium titanium oxide (LTO; Li4Ti5O12) is examined using scanning transmission electron microscopy with electron energy-loss spectroscopy (STEM–EELS). A single crystalline LTO specimen is prepared from a TiO2 wafer and is then partially lithiated. STEM–EELS spectrum imaging of the lithiated specimen reveals that the two phases exist separately inside the specimen with phase boundaries, and no apparent misfit strains or misorientations are detected. The phase interface appears to be preferentially formed parallel to the (100) plane owing to preferential Li diffusion along the <011> and equivalent directions in the LTO crystal. The observed two-phase morphology can be explained by the fact that relative to solid solutions, the Li7Ti5O12 phase can accommodate inserted Li atoms with negligible lattice distortions or volume changes in the common Ti–O bond framework.
This paper is focused on the design and the implementation of a hybrid PV-wind power system with batteries. It aims to emulate the behavior of a hybrid power system in order to face load consumption variations. Final system includes relevant contributions such as quality of emulator (a large number of parameters are considered); capacity to study various impacts simultaneously, a fast dynamic and a set of experimental tests that have been achieved and validated with a test bench. Moreover, a relevant supervision strategy based on currents control and batteries State Of Charge (SOC) estimation has been successfully performed despite simplicity of converter controls.
This paper presents a systematic review for the most commonly used lumped-parameter equivalent circuit model structures in lithium-ion battery energy storage applications. These models include the Combined model, Rint model, two hysteresis models, Randles' model, a modified Randles' model and two resistor-capacitor (RC) network models with and without hysteresis included. Two variations of the lithium-ion cell chemistry, namely the lithium-ion iron phosphate (LiFePO4) and lithium nickel-manganese-cobalt oxide (LiNMC) are used for testing purposes. The model parameters and states are recursively estimated using a nonlinear system identification technique based on the dual Extended Kalman Filter (dual-EKF) algorithm. The dynamic performance of the model structures are verified using the results obtained from a self-designed pulsed-current test and an electric vehicle (EV) drive cycle based on the New European Drive Cycle (NEDC) profile over a range of operating temperatures. Analysis on the ten model structures are conducted with respect to state-of-charge (SOC) and state-of-power (SOP) estimation with erroneous initial conditions. Comparatively, both RC model structures provide the best dynamic performance, with an outstanding SOC estimation accuracy. For those cell chemistries with large inherent hysteresis levels (e.g. LiFePO4), the RC model with only one time constant is combined with a dynamic hysteresis model to further enhance the performance of the SOC estimator.
The performance of a primary Mg-air cell was evaluated at room temperature using a 72mol% ethylene glycol/trihexyl(tetradecyl)phosphonium chloride ([P6,6,6,14][Cl]) ionic liquid (IL) electrolyte. The cell was cycling in ambient air as well as in the presence of pure oxygen, and interestingly the cell presented much higher discharge capacity in air than in oxygen, which was attributed to the effect of water in the ambient air. When operated in ambient air, the cell showed promising discharge behaviour with a maximum rate of 0.2mAcm−2 and a discharge capacity of around 4.8mAhcm−2. When operated at a low rate 0.0075mAcm−2, the cell lasted for over 260h, 10 days, at a potential above 1.3V. Thus, the main focus of this study is the analysis of the mechanism of discharge capacity loss in this electrolyte, which revealed that, both the polarization due to the presence of a resistive Mg interphase on the anode surface and, concentration polarization due to the quick accumulation of Mg2+ ions in the IL based electrolyte are responsible. In-depth surface characterization suggested the discharge products accumulated on the Mg surface with a proposed formula [P6,6,6,14]·Cl·Mg(OH)2·9[Mg(OCH2CH2OH)Cl]·40H2O most likely had a highly-crosslinked chemical structure, which were responsible for the limited ionic conductivity of the Mg interphase.
Thermal design and management are important for lithium-ion batteries (LIBs) to prevent thermal runaway under normal and abnormal conditions such as overcharge and short circuit. A sound understanding of the heat generation behaviors of LIBs is needed for their thermal design and management. Since battery characteristics such as capacity and power capability degrade with time and the number of cycles, one can infer that the amount of heat generated by LIBs may also be changed by this degradation. Calorimetry is an effective method of studying the heat generation mechanisms of LIBs. In this study, we apply calorimetry to characterize the heat generation behavior of LIBs during charging and discharging after degradation due to long-time storage. At low rates of charging and discharging, such as 0.1C, significant differences dependent on the degree of degradation are not observed. On the contrary, more degraded batteries exhibit greater heat generation related to overvoltage increase at high rates of charging and discharging, such as 1 C. The solution resistance increase is particularly striking in an LIB stored at 50 °C. The chief cause of this increase may be leakage of electrolyte solution, resulting in greater heat generation at high rates of charging and discharging.