batterydata/paper-abstracts huggingface dataset:
A method for modelling the thermal behaviour of a lithium-ion battery (LIB) during charge is presented. The effect of charge conditions on the thermal behaviour is examined by means of the finite element method. A comparison of the experimental charge curves with the modelling results validates the two-dimensional modelling of the potential and current density distribution on the electrodes of an LIB as a function of charge time during constant-current charge followed by constant-voltage charge. The heat generation rates as a function of the charge time and the position on the electrodes are calculated to predict the temperature distributions of the LIB based on the modelling results for potential and current density distributions. The temperature distributions obtained from the modelling are in good agreement with the experimental measurements.
Micro-short circuit (MSC) of a lithium-ion battery cell is a potential safety hazard for battery packs. How to identify the cell with MSC in the latent phase before a thermal runaway becomes a difficult problem to solve. We propose a diagnosis method to detect the MSC according to the remaining charging capacity (RCC) variations between cells. When the charging cell voltage curve (CCVC) of the first fully charged cell is regarded as the benchmark, the RCC of each cell can be obtained by the CCVC transformation based on the uniform CCVC hypothesis. The accuracy of the RCC estimation method is validated under constant current and constant power charging experiments. The leakage current of the MSC cell can be obtained by the increase of the RCC after each charge, and it can be converted into the MSC resistance. We set up the battery pack system model with the MSC fault in Simulink® to verify the effectiveness of the method when the battery pack is charged up to different charge cutoff voltages. Through a series of experiments with external resistors, the adaptability of the MSC diagnosis method is further validated for the aged cell, multi-stage charging, and constant power charging.
Over the past 50 years, significant advances have been made in the development of total artificial hearts (TAH). These advances have most recently led to a clinical trial of a unique, transcutaneously powered TAH.
Purpose To elucidate the influence of motion and posture of head on the newly developed ultraminiature cordless bruxism measurement system (BMS), we examined masseteric electromyographic (EMG) data of BMS during turning-over movements in bed in comparison with those of a conventional polygraph system (PG). Methods Twelve healthy subjects lay on their back and then turned to the right (right turn, 90°) and then to the left (left turn, 180°). Maximum amplitudes and root mean square (RMS) values of EMG data were calculated during the phase of turning movements. The data were high-pass filtered at 10Hz, 30Hz, 50Hz, and 100Hz. Results Artifact signals were visibly observed in PG measurement for all subjects and in BMS measurement for three subjects. Maximum amplitudes during right turn measured by BMS were significantly smaller than those measured by PG, while there was no significant difference during left turn. During right turn, RMS values high-pass filtered at 10Hz obtained by BMS were significantly smaller than those obtained by PG, while there was no significant difference between the data obtained by the two devices at the other cut-off frequencies. During left turn, there was no significant difference between RMS values obtained by the two devices. Conclusions Although BMS data were slightly affected by motion and posture of head during simulated sleep-turning, it was suggested that motion artifact of signals during BMS measurements is equivalent to or less than that during PG measurements, and BMS is thought to be suitable to measure sleep bruxism.
The electrochemical reactivity of Li3N with transition metals (M=Mn, Fe, Co, Ni) is examined by discharge/charge, cyclic voltammetry, X-ray diffraction and X-ray photoelectron spectroscopy measurements. An attempt is made to understand this reversible electrochemical reaction of transition metals with Li3N from the chemical reactions point of view. Density functional theoretical calculation results suggest that a stable complex MNLi3 could be formed by the insertion of transition metal in Li3N with exothermic as an intermediate, subsequent the decomposition process of these insertion compounds should make a main contribution to release Li.
A series of carbon supported PtAu electrocatalysts has been prepared. The performance of the samples in the methanol oxidation reaction and in the oxygen reduction reaction has been investigated by means of electrochemical techniques. The combined process, oxygen reduction reaction in the presence of methanol, has also been studied by electrochemical methods and in a single-cell. Irrespective of the performance of the samples in the oxygen reduction reaction, the ones displaying poor activity in the methanol oxidation reaction are the optimum cathode electrocatalysts for direct methanol fuel cell applications. The role of Au was found to be dependent on the actual nature of the catalyst. When alloyed, the role of Au on the methanol oxidation reaction is negligible. This is the first time that Au is being proposed as a component of methanol resistant cathode electrocatalysts.
Palladium nanoparticles modified with the hexadecyl-2-hydroxyethyl-dimethylammonium dihydrogen phosphate (HHDMA) ligand have been stabilised within the microchannels of a metallic monolith coated with a high-surface area γ-alumina layer. The stainless steel skeleton of the monolith was 3D printed by stereolithography. The washcoating protocol has been optimised in order to maximise the γ-alumina loading without blocking the microchannels. A battery of techniques has been applied to characterise the properties and three-dimensional organisation of the phases within the monolithic reactor from the macro- to the nanoscale including N2 sorption, X-ray diffraction, thermogravimetric analysis, nuclear magnetic resonance and infrared spectroscopies, X-ray tomography, and optical or electron microscopies. Evaluation of the catalyst performance in the flow hydrogenation of acetylenic compounds of different size and functionality demonstrates the high efficiency and stability of the structured catalyst. Particularly, the monolithic reactor retains the intrinsic selective character of the hybrid palladium nanoparticles, even at high temperatures and pressures (T > 343 K and P > 5 bar). This is attributed to the improved isothermicity of the catalyst bed, deriving from the high thermal conductivity of the metallic skeleton of the monolith. Overall, the work provides a general route to prepare monolithic reactors based on Pd-HHDMA nanoparticles, bridging the gap between hybrid nanomaterial and reactor engineering.
High-performance Fe3O4 polyhedrons as alkaline secondary battery anode materials have successfully been synthesized using a facile co-precipitation method with a subsequent annealing treatment at 700°C for 1h. The physical and electrochemical properties of the Fe3O4 samples annealed at different temperatures are investigated. It has been discovered that the annealing temperature plays a vital role in improving the physical and electrochemical performances of the Fe3O4 materials. The results also indicate that the Fe3O4 sample annealed at 700°C performs better (faster activation rate, higher specific discharge capacity, better high-rate ability and cycle stability) than the samples annealed at other temperatures. The specific discharge capacity of the 700°C-annealed Fe3O4 reaches 604.2mAh g-1 at a current density of 120mA g-1 with a charging efficiency of 83.9%. Moreover, discharge capacities of 587.6, 539.5 and 500.1 mAh g-1 are achieved at 240, 600 and 1200mA g-1, respectively, exhibiting remarkable high-rate discharge capability. This performance improvement may be attributable to better reaction reversibility, lower charge transfer impedance and better inhibiting effect on hydrogen evolution reaction of the material. We believe that this Fe3O4 polyhedron is a promising candidate as the anode material for high-performance alkaline secondary batteries.
The (SnOx-Sn)@few layered graphene ((SnOx-Sn)@FLG) composite has been synthesized by oxygen plasma-assisted milling. Owing to the synergistic effect of rapid plasma heating and ball mill grinding, SnOx (1 ≤ x ≤ 2) nanoparticles generated from the reaction of Sn with oxygen are tightly wrapped by FLG nanosheets which are simultaneously exfoliated from expanded graphite, forming secondary micro granules. Inside the granules, the small size of the SnOx nanoparticles enables the fast kinetics for Na+ transfer. The in-situ formed FLG and residual Sn nanoparticles improve the electrical conductivity of the composite, meanwhile alleviate the aggregation of SnOx nanoparticles and relieve the volume change during the cycling, which is beneficial for the cyclic stability for the Na+ storage. As an anode material for sodium-ion batteries, the (SnOx-Sn)@FLG composite exhibits a high reversible capacity of 448 mAh g−1 at a current density of 100 mA g−1 in the first cycle, with 82.6% capacity retention after 250 cycles. Even when the current density increases to 1000 mA g−1, this composite retains 316.5 mAh g−1 after 250 cycles. With superior Na+ storage stability, the (SnOx-Sn)@FLG composite can be a promising anode material for high performance sodium-ion batteries.
In this report, three-dimensional hierarchically structured aerogels constructed with ultrathin layered MoS2/graphene nanosheets (3DMG) synthesized with a facile one-pot hydrothermal method, are employed as anodes for lithium-ion batteries (LIBs) without conductive additives, polymer binders or metal current-collectors. Due to the integration of three-dimensional porous structure and ultrathin layered MoS2/graphene, the 3DMG aerogel anode exhibits a high reversible capacity and an excellent high-rate capability. In addition, the 3DMG aerogels anode maintains a capacity of ∼870mAhg−1 at 1Ag−1 after 200 cycles, demonstrating superior long-cycle performances of 3DMG aerogels at a high current density. The reported 3DMG aerogels have promising application potentials in highly-efficient lightweight LIBs.
A physics-based equivalent circuit model (ECM) is derived by applying finite volume method to a pseudo-two-dimensional (P2D) model of lithium-ion (Li-ion) batteries. Only standard passive components are used to construct the equivalent circuit, which reflects the fact that a Li-ion battery is an energy storage device. Voltages across and currents through the circuit elements in the ECM are identified with the respective internal electrochemical processes in the battery, thus allowing the parametric values of circuit elements to be expressed as functions of the Li-ion concentrations and temperature. Variations in the parametric values across the thickness of the battery leads to a distributed-parameter ECM amenable for wide range of applications. Furthermore, in contrast to existing reduced-order models of Li-ion battery which are described by differential algebraic equations, the ECM is governed by ordinary different equations wherein all the circuit components are expressed as explicit functions of the state and input variables. Hence, the developed model allows solution to be found directly using matrix algebra, resulting in rapid simulation study suitable for the development of computationally-efficient real-time battery control algorithm. Results of simulation based on the developed distributed-parameter ECM show close agreement with those obtained from a partial differential equation based P2D model under wide range of applied current rate, but at a much reduced computational burden.
In this study, we prepared a kind of composite solid polymer electrolyte (CSPE) based on montmorillonite (MMT) nano-clay fillers, lithium-bis(trifluoromethanelsulfonyl) (LiTFSI), polyvinylidenedifluoride (PVDF) and polyvinyl alcohol (PVA) copolymer by the casting method. Effect of the montmorillonite on ionic conductivity and electrochemical properties of the polymer electrolyte was demonstrated. The result CSPE obtained a higher ionic conductivity up to 4.31×10−4 Scm−1 at room temperature when 4.0wt% MMT was contained, and the maximum lithium ions transference number of 0.40 was achieved. Electrochemical performance of the polymer solid electrolyte was evaluated in Li/polymer electrolyte/LiFePO4 coin cell. Good performance with low capacity fading on charge–discharge cycling was achieved, indicating the potential application of the as-prepared CSPE in lithium ion batteries.
An unconventional high temperature fuel cell system, the liquid tin anode solid oxide fuel cell (LTA-SOFC), is discussed. A thermodynamic analysis of a solid oxide fuel cell with a liquid metal anode is developed. Pertinent thermochemical and thermophysical properties of liquid tin in particular are detailed. An experimental setup for analysis of LTA-SOFC anode kinetics is described, and data for a planar cell under hydrogen indicated an effective oxygen diffusion coefficient of 5.3×10−5 cm2 s−1 at 800°C and 8.9×10−5 cm2 s−1 at 900°C. This value is similar to previously reported literature values for liquid tin. The oxygen conductivity through the tin, calculated from measured diffusion coefficients and theoretical oxygen solubility limits, is found to be on the same order of that of yttria-stabilized zirconia (YSZ), a traditional SOFC electrolyte material. As such, the ohmic loss due to oxygen transport through the tin layer must be considered in practical system cell design since the tin layer will usually be at least as thick as the electrolyte.
Various compositions of silver-based quaternary superionic conducting (SIC) [AgI–Ag2O–(SeO2+P2O5)(SSP)] glasses were prepared by melt quenching technique. The X-ray diffraction (XRD) and conductivity studies were carried out to identify the amorphous nature and to select high ionic conducting composition of the SSP system for the fabrication of batteries. Solid-state primary batteries were fabricated using the 66.67%AgI–23.07%Ag2O–10.26%(0.3SeO2+0.7P2O5) (66SSP37) glass with different cathode materials [I:C, (I+C):SE and {(I+C)+SE}:TAAI, where I is Iodine, C is graphite, SE is solid electrolyte (SSP glass) and TAAI is tetraalkyl (methyl and butyl) ammoniumiodide]. The open circuit voltage (OCV), polarization and discharge characteristics were measured to estimate the lifetime of the batteries made up of SSP glass.
Resumen Objetivo Aportar nuevos valores de referencia de la Short Physical Performance Battery (SPPB) para personas de 70 y más años, en atención primaria de salud (APS), y analizar su asociación con variables demográficas, de función física, estado de salud y clínicas. Diseño Entrevistas y observaciones basales de un estudio longitudinal sobre función física y resultados adversos de salud. Emplazamiento 5 centros de atención primaria de las provincias de Alicante y Valencia. Participantes 593 personas de 70 y más años. Mediciones principales La SPPB se aplicó mediante observación directa y el resto de variables mediante entrevista. Se calcularon valores de referencia según sexo y 3 grupos de edad (70-75, 76-80, > 80 años) y se examinó la validez de la batería mediante estadísticos de asociación con variables demográficas, clínicas y de funcionamiento. Resultados Los valores de referencia indicaron peor desempeño en las mujeres y progresivamente peor desempeño a través de los 3 grupos de edad. La batería SPPB se asoció significativamente (p<0,01) con la edad, sexo, número de fármacos consumidos, morbilidad, índice de masa corporal, dependencia en actividades básicas de la vida diaria (ABVD), dependencia en actividades instrumentales de la vida diaria (AIVD) por motivos de salud, Physical Functioning Scale (PF-10), depresión y percepción de salud. Conclusiones Se aportan valores de referencia de la batería completa SPPB por edad y sexo, basadas en las puntuaciones categóricas, para personas de 70 y más años en atención primaria. La batería mostró además su validez como medida objetiva de funcionamiento físico. Estos resultados pueden favorecer la valoración rápida y válida del estado funcional de las personas mayores en atención primaria.
In vanadium redox flow batteries, an accumulated imbalance of the states-of-charge between the two half-cell electrolytes caused by vanadium ion crossover and gassing side reactions can result in only one half-cell achieving 100% state-of-charge, which is referred to as capacity loss that needs to be corrected online. In order to implement rebalancing control, online states-of-charge have to be monitored. In this paper, the electrolyte viscosity and its use for online state-of-charge monitoring design are investigated. The study firstly measures the viscosities of both V2+/V3+ and VO2+/VO2 + redox couples in sulfuric acid as the negative and positive half-cell electrolytes at different states-of-charge and temperatures, followed by establishing an empirical neural network model that correlates the state-of-charge to viscosity and temperature. To overcome the limitation in online viscosity measurements, Darcy’s law describing the flow of a fluid through a porous medium is further introduced to link the electrolyte viscosity to the pressure drop across a porous medium where the electrolyte solutions flow through. Together with the neural network model, the state-of-charge can be eventually represented as a function of pressure, temperature and flow rate that are readily measurable online, and accordingly an online state-of-charge monitoring design is developed, which could be readily integrated into the online battery control system for automated electrolyte rebalance. Experimental validation is performed on a 15-cell stack system and the results demonstrate the feasibility of the proposed method.
The effect of incorporating varying amounts (in the range 2.5–10vol%) of toluene additive in 1M LiCF3SO3 in tetra(ethylene glycol) dimethyl ether (TEGDME) liquid electrolyte on the electrochemical performance of Li/S cell at room temperature was studied. Cyclic voltammetry measurements showed the same active voltage range for the electrolytes with and without toluene, consisting of an oxidation peak at 2.5V and a pair of reduction peaks at 2.35 and 1.9V. Electrolytes with toluene have higher redox currents resulting from increased ion mobility and ionic conductivity. Toluene addition enhanced initial discharge capacity; a maximum of 750mAhg−1 (45% of the theoretical specific capacity of sulfur) was obtained with 5% of toluene, which was 1.8 times that of the cell without toluene. The electrolyte with 5% toluene exhibited a stable cycle performance with the highest discharge capacity and charge–discharge efficiency. AC impedance analyses of Li/S cells with the electrolytes showed that toluene addition resulted in a lower initial interfacial resistance and a fast stabilization of electrode/electrolyte interfaces in the cell. Addition of toluene in low amounts is thus an effective means to enhance the electrochemical performance of 1M LiCF3SO3 in TEGDME electrolyte in Li/S cells at room temperature.
Thermoelectrochemistry involves the study or application of temperature-dependant parameters in an electrochemical system. Thermoelectrochemistry can be exploited in non-isothermal cells to form thermogalvanic cells (or thermocells) to convert a temperature gradient into a useful electrical current. However, heat can also transfer and reduce the temperature gradient, while spillage is a potential issue for liquid electrolytes. For this reason, we have investigated aqueous thermocells containing potassium ferricyanide and potassium ferrocyanide (0.1MK3[Fe(CN)6]/0.1MK4[Fe(CN)6]) as a gelled electrolyte. Fumed silica and gelatine were not found to be sufficient gelling agents, whereas agar agar (agarose) and beads of poly(sodium acrylate) were found to form effective gelled electrolytes; the latter gel was also self-healing. Thermocells were prepared using commercial CR2032 battery casings, and surface treatments and preparations of the stainless steel electrodes evaluated for their electrocatalytic effects and influence on long-term current output. Emphasis was placed upon body heat harvesting, and preliminary heat transfer modelling through the CR2032 systems also performed. Ultimately, the gelled electrolytes were found to result in more stable power output and effectively frustrate heat transfer through the cells, relative to the un-gelled (liquid) electrolytes. These results will inform the development of both more efficient electrolytes and housings for thermocells.
Li3MnO4, a Mn5+-containing phase, is a promising cathode material for Li-ion batteries due to its very high theoretical capacity of 698Ah/kg. However, the possibility to exploit only part of the theoretical capacity and its rapid capacity fading prevents the use in Li-ion batteries. An ex-situ post mortem analysis combining XRD, SEM, XPS and Raman measurements revealed that lithium extraction or insertion gives rise to amorphization of the structure with conversion to a more stable amorphous MnO2 phase, already after the first cycle. Formation of solid electrolyte interface on the surface of the particles during discharge and its dissolution during charge was also demonstrated. In conclusion, a model for the degradation mechanism of Li3MnO4 in Li-ion batteries was proposed.
There is growing interest in ionic liquid based electrolytes for Na metal and Na-ion batteries. Here we compare three quite distinct bis(fluorosulfonyl)imide (FSI) anion based ionic liquids with small alkyl phosphonium (trimethyl isobutyl phosphonium, methyl tri-isobutyl: P111i4, P1i4i4i4) or alkoxy ammonium counter cations (N-ethyl-2-(2-methoxyethoxy)-N,N-bis(2-(2-methoxyethoxy)ethyl)ethan-1-ammonium bis(fluorosulfonyl)imide: N2(2O2O1)3) mixed at near 1:1 mol ratio with NaFSI. The conductivities of these electrolytes range from 4.4 mScm−1 for the smallest P111i4FSI:NaFSI system to 0.3 mScm−1 for the N2(2O2O1)3FSI:NaFSI mixture at 50 °C. This difference in conductivity is interestingly not reflected in the cyclic voltammetry for Na/Na+ where the maximum peak current density of 10 mAcm−2 is surprisingly high for the poorly conductive N2(20201)3FSI:NaFSI solution (e.g. 17 mAcm−2 for P111i4FSI:NaFSI). The overpotentials observed for Na symmetric cell cycling show very little differences after initial stabilising/conditioning for the three electrolytes being 50 mV for P111i4FSI:NaFSI and 100 mV for the others (at 0.1 mA cm−2). Also the Na+ transport number is similar for the three electrolytes ranging from 0.33 to 0.37. Full cells were prepared with layered transition metal oxide cathodes: O3-Na2/3(Fe2/3Mn1/3)O2), P2-Na2/3(Fe2/3Mn1/3)O2 and P2-Na2/3(Mn0.8Fe0.1Ti0.1)O2. While for the O3/P2-Na2/3(Fe2/3Mn1/3)O2 structures the device performance is consistent with the electrolyte properties, with the P2-Na2/3(Mn0.8Fe0.1Ti0.1)O2 cathode the N2(2O2O1)3FSI:NaFSI electrolyte cycling extremely well. The P111i4FSI and N2(2O2O1)3FSI yield almost equivalent specific capacities of approximately 180 and 160 mAhg−1 respectively at C/10 rate.
Lithium-ion batteries have been actively researched in recent years due to it being one of the most promising energy storage systems. Herein, we report a novel approach where germanium nanowires (Ge NW) are grown in gold-seeded porous carbon via the solution–liquid–solid mechanism, and the corresponding improvement observed in terms of the specific capacity of this porous carbon–germanium nanowires (PC–Ge NW) composite anode. At a current density of 160mAg−1 and voltage window of 0.001–1.5V, a specific capacity of 789mAhg−1 during the 50th cycle for PC–Ge NW is achieved as compared to 624mAhg−1 during the 50th cycle for pure Ge NW. Even though the content of the Ge is only 53.5 weight percent in the PC–Ge NW composite, it yields a better stability and higher specific capacity, indicating a synergistic effect between porous carbon and Ge nanowires. There is also potential cost savings since the use of a lower amount of Ge can bring about good cycling properties.