batterydata/paper-abstracts huggingface dataset:
A facile synthesis of vanadium oxide with reduced graphene oxide (rGO) is developed and used as cathode material for lithium ion batteries. VO2(B) nanorods and VO2(B)-rGO composite were prepared by a hydrothermal method using NaVO3 precursor and sodium oxalate as a reducing agent. The monoclinic phase and nanorod like morphology of synthesized materials were confirmed by XRD, SEM, and TEM respectively. The electrochemical properties of samples were investigated at 1.5–4.0 V, and 0.1 C rate, and the VO2(B) nanorods exhibit reversible capacity of about 159 mAh g−1, whereas VO2(B)-rGO exhibits 274 mAh g−1. The reasonable discharge capacities were obtained at high rates. The enhanced performance in electrical energy storage system reveals the effectiveness of rGO in the composite, as it enhances the conductive electron pathway to overcome the intrinsic limits of single phase VO2(B).
In the present study, an experimental evaluation of photovoltaic DC refrigerator with and without loading is carried out under different conditions. The experimental setup consists of photovoltaic (PV) panel, 12 V battery, charge controller and 158 L DC refrigerator. The refrigerator run with a 12 V DC compressor and incorporated with an AC/DC converter as a backup source. The temperature inside the refrigerator is adjusted through a thermostat. The effects of the variations of thermostat setting on the performance of the refrigerator were investigated. The daily ampere hour (Ah) generated from the photovoltaic panel is compared with daily ampere hour (Ah) consumed by the refrigerator for different configurations. Experimental results show that the refrigerator consumed less ampere hour (Ah) when the thermostat at lower position. However, it was found that the maximum consumption is recorded when the thermostat at higher position. More detailed test were conducted for the operation of the refrigerator without photovoltaic panel (battery only) and with AC/DC converter. The power consumption of the refrigerator with different loadings were also recorded and compared with power consumption without loading condition. It was observed that the thermostat setting position has a great effect on the energy consumption of the refrigerator.
A high-rate sulfur/carbon cathode is prepared by using high conductive hierarchical porous carbon-carbon fiber weave-structured (HPC-CF) materials as carbon host to disperse sulfur. Sulfur is infiltrated into porous carbon with meso/micropores by using an improved vapor-melting adsorption method, which aims to enhance sulfur dispersion and interaction with carbon host. Meanwhile, carbon fiber with weaved structure can connect the dispersed micron S/HPC particles on the current collector. As a result, a highly conductive network around the sulfur particles finally forms in the sulfur/carbon cathode. Results show that improved vapour-melting method can efficiently enhance the sulfur dispersion and interaction with carbon host. Electrochemical measurements show that both of the rate capacity and cycle stability of the sulfur/carbon cathode are significantly improved. It delivers a very high initial discharge capacity of 1692.9 mAh g−1 at 0.1C, and maintains 1030 mAh g−1 after 130 cycles at 0.5C. Furthermore, the weave-structured HPC-CF carbon materials increases the conductivity effectively, which enhances the rate performance of the prepared S/HPC-CF cathode. It shows 670.8 mAh g−1 at the first cycle and remains 520 mAh g−1 after 200 cycles at 6.0C with an average coulombic efficiency of 97.8%. The excellent cycle and rate performance of the prepared Sv-m/HPC-CF can be attributed to the high cathode conductivity, high sulfur utilization and strong interaction between sulfur and the HPC-CF materials.
In this paper, a particle swarm optimization (PSO)-based power dispatch algorithm is proposed to deal with the energy management problem of the hybrid generation system (HGS). For conventional PSO method, the search space is only defined by inequality constraints. However, as for power dispatch problems, it is vital to maintain power balance, which can be represented as an equality constraint. To address this issue, a roulette wheel re-distribution mechanism is proposed. With this re-distribution mechanism, unbalanced power can be reallocated to more superior element and the searching diversity can be preserved. In addition, the effect of depth of discharge on the life cycle of the battery bank is also taken into account by developing a penalty mechanism. The proposed method is then applied to a HGS consisting of photovoltaic array, wind turbine, microturbine, battery banks, utility grid and residential load. To validate the effectiveness and correctness of the proposed method, simulation results for a whole day will also be provided. Comparing with three other power dispatching methods, the proposed method can achieve the lowest accumulated cost.
Carbon nanotube/graphene oxide (CNT/GO) hybrid electrodes were synthesized via layer-by-layer (LBL) self-assembly. Transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and scanning electron microscopy (SEM) were carried out to characterize their microstructures, while Raman and Fourier transform infrared (FTIR) spectroscopy were used to investigate surface characteristics of the as-prepared samples. A 4-point probe was used to measure the electrical conductivities of the samples. Electrochemical properties of the CNT/GO hybrid electrodes were measured by cyclic voltammetry (CV), charge–discharge tests and electrochemical impedance spectroscopy (EIS). It was found that LBL self-assembled technique could directly synthesize CNT/GO hybrid materials on copper foils without any additives and the energy stored in these hybrid electrodes could be controlled by the electrode thickness. The electrode with a thickness of only 917.0nm delivered a reversible capacity of 0.265mAhcm−2 at a current density of 0.01mAcm−2. Even at a higher current density of 0.4mAcm−2, it still exhibited a reversible capacity of 0.030mAhcm−2. These CNT/GO hybrid electrodes with thicknesses of less than one micron might be promising candidates for energy storage in micro devices.
An innovative route to obtain Ni/NiO core-shell foam-based anodes for lithium-ion batteries is presented. Commercial Ni foams are conformally coated with NiO by ionic liquid-based electrodeposition. The electrochemical behavior of the resulting Ni/NiO electrodes in half coin cells with lithium counter electrode is investigated. The results are qualitatively correlated to the microstructural properties, including effects of the thermal annealing at 500°C, of the NiO shell. The formation a NiO sub-layer by the thermal oxidation of the Ni foam seems to play a crucial role in the enhanced performance of the annealed Ni/NiO anodes, which exhibit a reversible discharge capacity around 0.8 mAh/cm2. Furthermore, the Ni/NiO core-shell foam-based anodes are evaluated in full coin Li-ion cells with high voltage LiMn0.8Fe0.2PO4 cathode. Promising cyclability is reached in NiO-LMFP coin cells under cycling at 0.4C.
Most electrochemical measurements and characterizations rely on a three-electrode system to obtain useful information. Nevertheless, useful information can still be obtained with a two-electrode system when electrochemical measurements done with a three-electrode system become difficult or impossible. For example, cyclic voltammetry performing on an electrochromic device (ECD) at low scanning rates was proposed as a means to determine the limits of the safe operating voltage. In this study, voltammograms in a typical two-electrode cell is simulated digitally. It was found from the numerical simulation that the voltammograms of the cell could provide ‘fingerprints’ of an ECD. These fingerprints agree well with our earlier experimental observation that the cell characteristics are governed by the electrode with a lower charge capacity. To illustrate the validity of the simulation, complementary electrochromic system comprising the tungsten oxide–polyaniline pair will be discussed. Useful criteria for cell design are also presented.
In this paper, MnO2·xH2O/carbon aerogel (CRF) composite electrode materials were prepared by a chemical co-precipitation method. The structure and morphology of MnO2·xH2O/CRF were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that carbon aerogel was an amorphous material with a pearly network structure, the MnO2·xH2O powders possessed, a nanoscaled structure, and thus the MnO2·xH2O/CRF composite materials were nano-sized particles with a relatively high specific surface area. Electrochemical performance of the composite electrodes with different ratio's was studied by cyclic voltammetry and galvanostatic charge/discharge measurements. The results indicated that MnO2·xH2O/CRF composite electrodes had good electrochemical performance, high reversibility and high charge–discharge properties. Moreover, when the loading amount of MnO2·xH2O was 60%, the composite material has a high specific capacitance of 226.3Fg−1, while the capacitance of carbon aerogel electrode alone was 112Fg−1. Besides, MnO2·xH2O/CRF composite supercapacitors showed a stable cycle life in the potential range of 0–1.0V and retained 90% of initial capacitance over 400 cycles.
A novel ionic liquid gel electrolyte was successfully prepared and used in dye-sensitized solar cells. The ionic liquid gel was formed via the self-assembly of a low molecular weight gelator in ionic liquid. The properties of the ionic liquid gel were measured by POM, gel-to-sol phase transition temperature, cyclic voltammogram. All the ionic liquid gels appeared as soft solid at room temperature and become liquid at a high temperature. The ionic liquid gel showed a room temperature conductivity of 2.9mScm−1. The DSSC with ionic liquid gel electrolyte not only showed a photoconversion efficiency of 3.63%, but also exhibited a better long-term stability than the DSSC with the liquid electrolyte at the same conditions. Since the ionic liquid gel electrolyte is solvent-free, highly conductive and electrochemically compatible, it is possible to use this type electrolyte for development of practical DSSCs.
The technological development and economic of scale for solar photovoltaic (PV), batteries and combined heat and power (CHP) have led to the technical potential for a mass-scale transition to off-grid home electricity production for a significant number of utility customers. However, economic projections on complex hybrid systems utilizing these three technologies is challenging and no comprehensive method is available for guiding decision makers. This paper provides a new method of quantifying the economic viability of off-grid PV+battery+CHP systems by calculating the levelized cost of electricity (LCOE) of the technology to be compared to centralized grid electricity. The analysis is inherently conservative as it does not include the additional value of the heat form the CHP unit. A case study for residential electricity and thermal demand in an extreme worst case environment (Houghton, Michigan) is provided to demonstrate the methodology. The results of this case study show that with reasonable economic assumptions and current costs, PV+battery+CHP systems already provide a potential source of profit for some consumers to leave the grid. A sensitivity analysis for LCOE of such a hybrid system was then carried out on the capital cost of the three energy sub-systems, capacity factor of PV and CHP, efficiency of the CHP, natural gas rates, and fuel consumption of the CHP. The results of the sensitivity provide decision makers with clear guides to the LCOE of distributed generation with off-grid PV+battery+CHP systems and offer support to preliminary analysis that indicated a potential increase in grid defection in the U.S. in the near future.
Carbon nanofiber (CNF) supported cobalt oxide composites as high-capacity anode materials were prepared through a facile, effective method for potential use in rechargeable lithium-ion batteries. The effects of the calcining temperature on the crystallinity, grain size, specific surface area of Co3O4 and phase transformation from Co3O4 to CoO were studied in detail. Both the specific surface area and CNF content in CNF–cobalt oxide composites strongly affect the electrochemical performance of these series composites. The CNF–Co3O4 composite with 24.3% CNF pyrolyzed at 500°C in Ar shows an excellent cycling performance, retaining a specific capacity of 881mAhg−1 beyond 100 cycles. Homogeneous deposition and distribution of nanosized Co3O4 particles on the surface of CNF can stabilize the electronic and ionic conductivity as well as the morphology of Co3O4 phase, which may be the main reason for the markedly improved electrochemical performance.
Two iso-structural end members of the family of orthosilicates, i.e. Li2MSiO4 (M=Mn and Fe) and their solid solutions, were prepared and electrochemically characterized for potential use in Li-ion batteries. Due to the low specific conductivity (∼5×10−16 Scm−1 for Li2MnSiO4 and ∼6×10−14 Scm−1 for Li2FeSiO4 at room temperature), small particles in an intimate contact with a conducting phase (i.e. carbon) are needed. Li2MSiO4/C composites (M=Mn and/or Fe) prepared by the Pechini synthesis generally leads to 30–50nm large particles embedded in a carbon matrix. The amount of carbon in the composite is close to 10wt.% for the Li2FeSiO4/C composite and slightly more than 5wt.% for the Li2MnSiO4/C composite. In situ XRD experiment confirms a structural collapse of Li2MnSiO4 and the observed structural stability is completely different for Li2FeSiO4, which undergoes a fully reversible two-phase transition. Solid solutions between Li2MnSiO4 and Li2FeSiO4 in principle lead to higher capacities (>1e− per transition metal is feasible). For a long-term operation the cut-off voltage should be properly chosen. Electrochemical characterisation and in situ XRD experiments suggest the use of cut-off voltage close to 4.2V.
Whether or not alternative fuel vehicles (AFVs) will finally find a place in the global mass-market or even will dominate the vehicle segment will depend on several success factors: reduction of customer anxiety, fast recharging, better charging infrastructure, environmental justice policies and some others. Current technological advances in battery electric vehicles and hydrogen fuelled electric vehicles could represent a hopefully option in the near future. Nevertheless, and until electric/hydrogen technological barriers are not torn down, both power architecture do not have an opportunity to be fully introduced in the vehicle market. In this paper, the authors present a powertrain architecture concept based in current fossil fuel extender range, but changing it to a hydrogen fuel cell stack system that works as range extender. The objective is to probe how optimization techniques, by the inclusion of genetic algorithms, could be a crucial help when planning the fuel consumption/selection. The paper ambition is to highlight the possibilities of this powertrain and its appropriated management to allow hydrogen become an energy carrier feasible today in the automotive world.
With the pressing demand of climate change mitigation, the rapid technological development and market adoption of battery electric vehicles are imperative. However, the diverse consumption attitudes and their interactions, which are rarely considered, can significantly affect the adoption potential of battery electric vehicles. On the basis of three years of global positioning system data of 1.6 million people, we estimated the travel and adoption demands of battery electric vehicles in Japan considering diverse consumption attitudes. Under the current construction conditions for public charging systems and charging technologies, the adoption potential of battery electric vehicles may not be as promising as previously expected, and the government still faces great pressure to respond to the market share target. Given the current level of battery technology, technical and policy improvements such as fast charging, reducing the production cost, perfecting the public charging infrastructure, and increasing purchasing subsidies were found to be more effective than improving the battery capacity at increasing the adoption potential of battery electric vehicles.
Ni0.5TiOPO4 oxyphosphate exhibits good electrochemical properties as an anode material in lithium ion batteries but suffers from its low conductivity. We present here the electrochemical performances of the synthesized Ni0.5TiOPO4/carbon composite by using sucrose as the carbon source. X-ray diffraction study confirms that this phosphate crystallizes in the monoclinic system (S.G. P21/c). The use of the Ni0.5TiOPO4/C composite in lithium batteries shows enhanced electrochemical performances compared with the uncoated material. Capacities up to 200mAhg−1 could be reached during cycling of this electrode. Furthermore, an acceptable rate capability was obtained with very low capacity fading even at 0.5C rate. Nevertheless, a considerable irreversible capacity was evidenced during the first discharge. In situ synchrotron X-ray radiation was utilized to study the structural change during the first discharge in order to evidence the origin of this irreversible capacity. Lithium insertion during the first discharge induces an amorphization of the crystal structure of the parent material accompanied by an irreversible formation of a new phase.
The operation of vanadium redox flow batteries requires reliable in situ state of charge (SOC) monitoring. In this study, two SOC estimation approaches for the negative half cell are investigated. First, in situ open circuit potential measurements are combined with Coulomb counting in a one-step calibration of SOC and Nernst potential which doesn't need additional reference SOCs. In-sample and out-of-sample SOCs are estimated and analyzed, estimation errors ≤ 0.04 are obtained. In the second approach, temperature corrected in situ electrolyte density measurements are used for the first time in vanadium redox flow batteries for SOC estimation. In-sample and out-of-sample SOC estimation errors ≤ 0.04 demonstrate the feasibility of this approach. Both methods allow recalibration during battery operation. The actual capacity obtained from SOC calibration can be used in a state of health model.
We present a vanadium redox flow battery with a tubular cell design which shall lead to a reduction of cell manufacturing costs and the realization of cell stacks with reduced shunt current losses. Charge/discharge cycling and polarization curve measurements are performed to characterize the single test cell performance. A maximum current density of 70 mAcm−2 and power density of 142 Wl−1 (per cell volume) is achieved and Ohmic overpotential is identified as the dominant portion of the total cell overpotential. Cycling displays Coulomb efficiencies of ≈95% and energy efficiencies of ≈55%. During 113 h of operation a stable Ohmic cell resistance is observed.
TiO2-reduced graphene oxide (rGO) nanocomposite (TiO2-rGO) is fabricated by microwave-assisted forced hydrolysis and examined as prospective electrode for energy storage applications, especially in Li-ion battery (LIB) and Li-ion capacitor (LIC). First, the uniformly distributed nanoscopic TiO2 particulates (∼3 nm) over rGO nanosheets is evaluated as anode in half-cell assembly to ascertain the Li-insertion behavior and found that ∼0.68 mol Li (∼227 mAh g−1) is reversible. Then, “rocking-chair” type LIB is fabricated with spinel LiMn2O4 cathode, and the LiMn2O4/TiO2-rGO assembly exhibits high capacity (∼120 mAh g−1 at 0.1 C rate), good rate capability (∼53 mAh g−1 at 1 C rate), and excellent cycleability (∼90% initial reversible capacity after 1000 cycle) as well. Similarly, the LIC is also constructed with activated carbon cathode, and such configuration delivered a maximum energy density of ∼50 Wh kg−1 with ∼82% retention after 4000 cycles. The synergistic effect of both rGO and anatase nanoparticles provides excellent energy efficiency and battery performance in different kind of Li-ion based energy storage devices.
A novel electrode material for sodium-ion batteries (NIBs), Na3V2(PO4)3 with a rhombohedral, Na+ superionic conductor (NASICON)-type structure, was synthesised via a solid-state carbon-thermal reduction reaction assisted by mechanochemical activation. Electron microscopy analysis showed that the synthesised Na3V2(PO4)3 particles had an average size of 300 nm, being coated with a uniform layer of carbon 3 nm in thickness. As a cathode material, Na3V2(PO4)3/C exhibited an initial specific discharge capacity of 98.17 mAh g−1 at 0.1C for potentials ranging from 2.5 to 3.8 V. This was owing to the V3+/V4+ redox couple, which corresponded to the two-phase transition between Na3V2(PO4)3 and NaV2(PO4)3. The cathode lost 4.92% of its discharge specific capacity after 50 cycles. As an anode material, Na3V2(PO4)3/C exhibited an initial specific discharge capacity of 63.2 mAh g−1 at 0.1C for potentials ranging from 1.0 to 2.5 V. This was owing to the V2+/V3+ redox couple, which corresponded to the two-phase transition between Na3V2(PO4)3 and Na4V2(PO4)3. The anode lost approximately 5.41% of its discharge specific capacity after 50 cycles. The three-dimensional channel structure of NaV2(PO4)3 and the changes induced in its lattice parameters during the charge/discharge processes were simulated on the basis of density functional theory.
Metal sulphide electrocatalyst is considered as one of the most promising low-cost candidates for oxygen evolution reaction (OER). In this work, we report a novel free-standing Cu2S branch array via a facile TiO2-induced electrodeposition-sulfurization method. Interestingly, cross-linked Cu2S nanoflake branch is strongly anchored on the TiO2 backbone forming high-quality Cu2S/TiO2/Cu2S core-branch arrays. The branch formation mechanism is also proposed. As compared to the pure Cu2S nanowire arrays, the as-prepared Cu2S/TiO2/Cu2S core-branch arrays show much better alkaline OER performance with lower overpotential (284 mV at 10 mA cm−2) and smaller Tafel slope (72 dec−1) as well as enhanced long-term durability mainly due to larger exposed area and more active electrocatalytic sites. Our work provides a new way for construction of advanced metal sulphide electrocatalysts for electrochemical energy conversion.
To enhance the electrochemical performance of SiO, a simple electroless plating and ultrasonication method is used to prepare SiO/Cu/expanded graphite(EG) composite. Electrochemical results show that the electrode has a reversible specific capacity of 836 mAh/g and the capacity retention ratio is 90.2% in the 100th cycle at 200 mA/g current density (25 °C). Moreover, real time stress measurements quantitatively show that EG effectively suppresses stress development in the electrodes, which results in good cycling performance.
In the present work, various LiFePO4/carbon composites were prepared through a facile solvothermal route followed by heat treatment. These as-prepared LiFePO4/carbon composites, including LiFePO4/acetylene black (95:5wt.%), LiFePO4/carbon nanotube (95:5wt.%) and LiFePO4/graphene (95:5wt.%), were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Their electrochemical performances were also investigated and compared in detail. The achieved results indicate that both particle-size and electrochemical performance of LiFePO4 much depend on the carbon supporter. When acetylene black and carbon nanotube were used as carbon supporter, the prepared LiFePO4 particles were agglomerate together to form large-size second particles which cannot well connect with carbon supporter. In the LiFePO4/graphene composite, ∼50nm LiFePO4 particles uniformly loaded on the two-dimensional carbon supporter, and thus display much better rate ability. This result suggests that graphene should be a promising carbon supporter for LiFePO4.