batterydata/paper-abstracts huggingface dataset:
This study investigated the effects of silica (SiO2) additive in the positive electrode on the high-rate discharge performance of sealed lead-acid cells. X-ray diffraction studies reveal that the plate's chemical composition and crystal morphology is independent of the SiO2 additive in the positive electrodes. Cells with SiO2 additive in the positive plates decrease the active material, causing a lower initial capacity. However, the plates with SiO2 additive exhibit a smaller pore size, which has a good mechanical strength and retains the electrolyte in the pore during high-rate discharge causing a lower capacity loss per cycle and a higher average capacity per cycle. Apparently, the SiO2 additive has the beneficial effect of decreasing the capacity loss during the high-rate discharge cycles. Moreover, the discharge capacity loss rate does not correlate with the amount of SiO2 additives. Adding more SiO2 additives to the positive electrode decreases the active material appreciably causing a lower average capacity. The optimal amount of SiO2 additive is about 3wt%. The phase composition of the positive electrodes at different locations was determined after the cells completed the high-rate cycle test. The results reveal that the higher utilization of electrode plates at high-rate discharge occurred through the terminal and diagonal areas.
The sizing optimization of a Stand-Alone Photovoltaic system (SAPV) is a very complex issue. Therefore, a compromise solution must be made between having an acceptable energy and economic cost for the consumer, and a relatively correct energy supply quality. The Gross Energy Requirement (GER) of an SAPV system corresponds to the primary energy total amount required for the production, the maintenance and the recycling of this system. Reducing the GER is thus, an effective way to promote the development of SAPV systems. Therefore, the load profile management, in order to get closer to the ideal “solar” consumer, allows the downsizing of the system. In this paper, a methodology for studying the impact of load profiles on GER is proposed. Two different modifications parameters have been considered theoretically on idealized load and production profiles: the load shifting which seems simpler to implement in the reality, and the amplitude modulation. Furthermore, the NSGA-II genetic algorithm has been used to confirm theoretical outcomes and to optimize SAPV system sizing for three realistic load profiles, with the aim of quantifying the GER reduction, by minimizing the storage capacity (taking into account the replacements due to cycling) which is one of the weak points of such a system, and by PV panels downsizing.
Hydrogen energy storage has been considered as a key enabler for exploring novel materials with unique structures and properties, however, inadequate storage capacity, and instability leading to low performances. Metal organic compounds contain a core transition metal ion in accordance to their organic environment, allowing localized and enhanced hydrogen storage. Here, we show a superior hydrogen storage system, with around 1850 mAh/g discharge capacity and around 74% charge-discharge efficiency, performing rectangular nanocuboids beta copper phthalocyanine (β-CuPc). Primarily, β-CuPc has been synthesized in ethylene glycol (EG) via stepwise thermal treatments up to ∼185 °C with demonstrating its morphological and structural properties. Interestingly, unique surface morphology of as-synthesized β-CuPc (with about 163 nm width and 47 nm height) comes to our preliminary expectations as a relevant host for hydrogen sorption. Our work can expand into the classes of materials that can be used efficiently in hydrogen storage technology, and also opening a new channel to the wide range of mobile applications, either in academia or industries.
The booming developments in portable and wearable electronics promote the design of flexible energy storage systems. Flexible supercapacitors and batteries as promising energy storage devices have attracted tremendous attention. As the key component of both supercapacitors and batteries, electrode materials with excellent flexibility should be considered to match with highly flexible energy storage devices. Owing to large surface area, good thermal and chemical stability, high conductivity and mechanical flexibility, graphene-based materials have been widely employed to serve as promising electrodes of flexible energy storage devices. Considerable efforts have been devoted to the fabrication of flexible graphene-based electrodes through a variety of strategies. Moreover, different configurations of energy storage devices based on these active materials are designed. This review highlights flexible graphene-based two-dimensional film and one-dimensional fiber supercapacitors and various batteries including lithium-ion, lithium–sulfur and other batteries. The challenges and promising perspectives of the graphene-based materials for flexible energy storage devices are also discussed.
Lithium cobalt silicate Li2CoSiO4 is a promising but very challenging high energy cathode material for lithium-ion battery. This work presents a systematic study of synthesis-structure-performance of Li2CoSiO4, in which carbon coating and P doping are incorporated in nano-particles synthesized by hydrothermal reactions and the collaboration among different mechanisms of modification results in controlled synthesis of polymorphs and advanced electrochemical performance. The carbon coated Li2CoSiO4 sample exhibits improved electrochemical performance with a reversible capacity of 112 mAh g−1 at room temperature. Furthermore, 10% P substituted Si in Li2CoSiO4/C demonstrates a single form in polymorphs with much higher discharge capacity of 144 mAh g−1. The analysis of cyclic voltammograms and ex situ XRD indicates Li2CoSiO4 bears electrochemical characters of stable structure and high discharge voltage plateau during cycling. First-principles calculations on P-doping Li2CoSiO4 models find the P-doping site to be a repulsively positive center that suppresses the asymmetrical stress of Li+ and Peierls distortion in the delithiated structures, therefore promoting the deintercalation in the electrochemical performance.
A graphene loading heterogeneous hydrated forms iron based fluoride (abbreviated as FeF3·xH2O/G) nanocomposite is successfully designed and synthesized for the first time by a sol–gel method. It found that the FeF3·xH2O nanoparticles distribute randomly on the surface of the graphene, stacking together to form a nanocomposite with high specific surface and abundant mesporous structure. The FeF3·xH2O was consisted of FeF3·3H2O and FeF2.5·0.5H2O with pyrochlore phase structure and FeF3·0.33H2O with hexagonal-tungsten-bronze-type structure (HTB). The FeF3·xH2O/G was used as cathode materials of rechargeable lithium/sodium batteries, respectively. It has been found that it can deliver a large reversible capacity exceeding 200 mAh g−1 and excellent cyclic performance with a residual capacity of 183 mAh g−1 after 100 cycles at 0.2C and 149 mAh g−1 after 200 cycles at 1C, especially, an outstanding rate performance exceeding 130 mAh g−1 at 5C in the voltage range of 1.5–4.5 V for Li-ion batteries. Moreover, when FeF3·xH2O/G is used as cathode material of Na-ion batteries, it exhibits also a high reversible capacity of 101 mAh g−1 after 30 cycles in the voltage range of 1.0–4.0 V at 0.1C. Therefore, FeF3·xH2O/G will a promising cathode material for high-performance lithium/sodium ion batteries.
Polyvinylpyrrolidone (PVP) is presented as a “greener” alternative to commonly used supercapacitor binders, namely polyvinylidenedifluoride (PVDF) or polytetrafluoroethylene (PTFE). The key advantages of using PVP are that it is non-toxic and soluble in ethanol and it can be used to spray coat or drain cast activated carbon (AC) electrodes directly on a current collector such as aluminum foil – in contrast to PTFE that requires rolling or PVDF that requires toxic N-methylpyrrolidone (NMP). The electrodes with the best mechanical stability incorporated 3.5 mass% of 1.300.000 g mol−1 PVP. Compared to PTFE or PVDF, the resulting pore volume was significantly higher and the specific surface area significantly larger when using PVP (normalized to the amount of AC). A good electrochemical performance was observed in organic electrolytes for AC–PVP electrodes: 112 or 97 F g−1 at 0.1 A g−1 in 1 M TEA–BF4 in propylene carbonate or acetonitrile, respectively. The performance stability was comparable to PTFE-bound electrodes when adjusting the maximum cell voltage to 2.5 V while preserving the manufacturing features of PVDF–AC films. (Electro)chemical stability is shown by electrochemical testing and infrared vibrational spectroscopy for propylene carbonate and acetonitrile.
A Sm2O3 decorated carbon aerogel (CA-Sm) was successfully synthesized through a sol-gel from resorcinol, phloroglucinol (P), formaldehyde and catalyst of oxalic acid and doping compound with Sm2O3 strategies. The small amount of active reactant phloroglucinol promotes synthesis of carbon aerogel (CA) and formation of uniform and porous carbon spheres. The CA-Sm composites present an interlinked porous structure and high specific surface area. The CA-Sm with sulfur loading (CA/S-Sm) from the composite via molten sulfur technique exhibits an enhanced performance with long-term cycling stability and high rate capacity. In particular, the cathode of CA/S-Sm-2 with Sm/C molar ratio of 2/400 achieved a high initial discharge capacity of 1347 and 976mAhg−1 at 0.2C and 2C, respectively. And the cathode exhibited a nice long-term cycling stability with a high initial discharge capacity of 1175mAhg−1 and maintained 861mAhg−1 after 300 cycles at 0.5C. The excellent electrochemical performance of the battery is attributed to interrelated nanospheres, porous carbon structure, large specific surface area of Sm2O3-doped CA composites and improved electronic and ionic transport at the cathode.
Three different morphology controlled copper oxide materials (porous microspheres, flower-like, and thorn-like CuO) were prepared by facile and environmentally friendly processes, which were further investigated for their electrochemical properties and performance at lithium-ion battery anodes. CuO microspheres were prepared by simply solution chemistry, whereas flower-like and thorn-like CuO structures were prepared hydrothermally, with the structural transformations arising due to selection of chloride or sulfate counter ions in the precursor salts, respectively. After a 400°C heat treatment in air, the morphology controlled materials demonstrated excellent phase purity as indicated by X-ray diffraction (XRD), and we propose a growth mechanism for the various materials based on systematic investigation of the structure and properties of the intermediate species. The electrochemical and lithium-ion battery performance employing the shape controlled CuO materials was investigated, allowing for elucidation of the synthesis–structure–performance correlations of CuO-based anodes. The performance of lithium-ion batteries was found to be highly dependent on the CuO morphology. The CuO microspheres exhibit a superior electrochemical performance to the other two CuO samples in terms of cycle capacity and rate performance, indicating a viable strategy to prepare next-generation lithium-ion battery systems with improved storage capacities.
Theoretical calculations are compared with well-controlled experiments conducted on a high-surface area, small diameter lithiated-carbon electrodes. The electrodes are shown to yield very high current densities and exhibit little interfacial kinetics resistance or intercalate diffusion resistance. The mathematical treatment describes quantitatively a wide range of electrochemical experiments. The application of the model to the experimental data is facilitated by the use of a reference electrode. Initial cycling behavior of the high-surface-area electrode is elucidated, including clarification of the first-cycle coulombic inefficiency. Nitrogen absorbtion and scanning electron micrographs are utilized to ascertain the microstructural characteristics that distinguish the active electrode material. An asymptotic analysis is used to indicate when diffusion resistance within host particles is negligible; this fact simplifies model calculations and contributes to our overall understanding of insertion processes associated with host particles of very small dimensions.
A new flexible gel polymer electrolytes (GPE) with interpenetrating cross-linked network is fabricated by blending long-chain polyacrylonitrile (PAN) polymer matrix and short-chain triethylene glycol diacetate-2-propenoic acid butyl ester (TEGDA-BA) framework, with the purpose of enhancing the mechanical stability of the GPE frameworks via synergistic effects of the linear polymers and crosslinked monomers. The as fabricated frameworks enable the liquid electrolytes to be firmly entrapped in the polymeric matrices, which significantly improves the mechanical bendability and interface stability of the resultant GPE. The GPE with 5 wt% PAN exhibits high ionic conductivity up to 5.9 × 10−3 S cm−1 at 25 °C with a stable electrochemical window observed (>5.0 V vs. Li/Li+). The Li|GPE|LiFePO4 half cells demonstrate remarkably stable capacity retention and rate ability during cycling tests. As expected, the LiFePO4|GPE|Li4Ti5O12 full cells also exhibit discharge capacity of 125.2 mAh g−1 coupled with high columbic efficiency greater than 98% after 100 cycles. The excellent mechanical flexibility and charge/discharge performance suggest that the GPE holds great application potential in flexible LIBs.
Spherical carbon-coated natural graphite (SCCNG) is a promising anode material for lithium-ion batteries, but the smooth surface of graphite spheres is difficult to wet with an aqueous binder solution, and lacks electrical contacts. As a result, the cycle performance of such a graphite anode material is not satisfactory. An effective method has been introduced to tightly connect adjacent SCCNG particles by a highly conductive binder, viz. acetylene black bridges. The effect of the conductive bridges on the cyclability of SCCNG electrode has been investigated.
The development of green and clean synthetic techniques to overcome energy requirements have motivated the researchers for the utilization of sustainable biomass. Driven by this desire we choose rice as starting materials source. After the explosion effect, the precursor is converted into puffed rice with a honeycomb-like structures composed of thin sheets. These honeycomb-like macrostructures, effectively prevent the cross-linking tendency towards the adjacent nanosheets during activation process. Furthermore, tuneable micro/mesoporous structures with ultrahigh specific surface areas (SBET) are successfully designed by KOH activation. The highest SBET of 3326 m2 g−1 with optimized proportion of small-mesopores is achieved at 850 °C. The rice-derived porous N-doped carbon nanosheets (NCS-850) are used as the active electrode materials for supercapacitors. It exhibites high specific capacitance specifically of 218 F g−1 at 80 A g−1 in 6 M KOH and a high-energy density of 104 Wh kg−1 (53 Wh L−1) in the ionic liquid electrolytes. These are the highest values among the reported biomass-derived carbon materials for the best of our knowledge. The present work demonstrates that the combination of “puffing effect” and common chemical activation can turn natural products such as rice into functional products with prospective applications in high-performance energy storage devices.
Research on flood disasters in the past decade has impacted outcomes such as spirituality and social support. A number of studies have shown that flood also changes the vicitms’ belief about themselves and meaning of life. The purpose of this paper is to explore the relationship between spiritual and social support. The paper is based on a quantitative approach by conducting a survey on 764 flood victims. A questionnaire battery including a translated Malaysian version of spirituality and a Modified version of social support were administered to households in flood affected areas. All analysis were carried out using Statistical Package For The Social Science (SPSS Version 21). The study found that there was significant relationship between spirituality and social support (r=202**, family, r=286**,friends, r=210** and significant others, r=.448**) in flood victims. In sum, this study provide theoretical contributions to spirituality and social support research. The study of the role of spirituality and social support in fostering resilience in flood survivors may advance the understanding of human adaptation and coping to flood trauma.
Birnessites containing K+ and Na+ in the interlayer have been prepared by a sol–gel method using glucose and polyvinyl alcohol as reducing agents. The samples have been characterised by elemental chemical analysis, powder X-ray diffraction, thermal analysis (differential and thermogravimetric), FT-IR spectroscopy and specific surface area and texture assessment by nitrogen adsorption at −196°C. The solids obtained are more crystalline than those prepared by oxidation with H2O2 in a basic medium. The samples are thermally stable and evolution upon calcination at high temperature depends on the precise nature of the interlayer cation. So, calcination at 600°C of a K-birnessite leads to formation of cryptomelane (2×2 tunnel structure), while the Na analogue leads to formation of mixed Mn–Na oxides with different tunnel structures. Ion exchange of interlayer cations takes place topotactically at room temperature; Li+ enters easily in the interlayer, while the entrance of Mg2+ is more difficult, probably because of its high stability in the hydrated form; increasing of the temperature and contacting time during ion exchange does not improve very largely the process.
Overcharge is one of the most severe safety problems for the large-scale application of lithium-ion batteries, and in-depth understanding of battery overcharge failure mechanism is required to guide the safety design of battery systems. In this paper, the overcharge performance of a commercial pouch lithium-ion battery with Li y (NiCoMn)1/3O2-Li y Mn2O4 composite cathode and graphite anode is evaluated under various test conditions, considering the effects of charging current, restraining plate and heat dissipation. Charging current is found to have only minor influences on battery overcharge behaviors, whereas the battery overcharged with pressure relief design (restraining plate and cuts on pouches) and good heat dissipation shows significantly improved overcharge performance and can endure larger amount of overcharge capacity and higher temperature before thermal runaway. Characterizations on cathode and anode materials at different overcharge states are carried out to identify the side reactions inside the battery. The overcharged cathode suffers from electrolyte decomposition, transition metal dissolution and phase transition, but still exhibits no obvious exothermic behaviors before thermal runaway occurs. Severe lithium plating happens on the anode, and would accelerate the overcharge-induced thermal runaway process. Further analysis on the onset temperature of thermal runaway helps to reveal the overcharge-induced thermal runaway mechanism of lithium-ion batteries. The result shows that rupture of the pouch and separator melting are the two key factors for the initiation of thermal runaway during overcharge process.
A versatile synthetic approach is demonstrated to fabricate vanadium pentoxide hierarchical structures with three-dimensional electron carriers as anode materials for lithium-ion battery. Such unique structures are favorable for providing easy access of electrolyte to the electrode during lithiation-delithiation process and also shortening the pathway of the ion and electron transport, which guarantee excellent electrochemical performance. As a consequence, high specific capacities of 960 mAh g−1 at 200 mA g−1 and 738 mAh g−1 at 500 mA g−1 after 300 cycles are achieved without obvious decay. More remarkably, it is essential to rebuild a new recycling process owing to the massive waste produced by dealing with spent lithium-ion battery. Therefore, an energy-saving and environment-friendly process is introduced to recycle the used V2O5 batteries. Through a facile annealing process, LiV3O8 is obtained and reused as sustainable anode materials for the first time. The recycled product LiV3O8 delivers excellent electrochemical performance, e.g., a high capacity of 542 mAh g−1 at 200 mA g−1 and the coulombic efficiency of over 99% after 600 cycles. This finding not only promotes the development of vanadium oxides for lithium-ion battery, but also sheds light on searching potential protocol for metal ion battery recycling.
This paper presents an algebraic method for parameter identification of Thevenin's equivalent circuit models for batteries under non-zero initial condition. In traditional methods, it was assumed that all capacitor voltages have zero initial conditions at the beginning of each charging/discharging test. This would require a long rest time between two tests, leading to very lengthy tests for a charging/discharging cycle. In this paper, we propose an algebraic method which can extract the circuit parameters together with initial conditions. This would theoretically reduce the rest time to 0 and substantially accelerate the testing cycles.
Iron oxide materials are attractive anode materials for lithium–ion batteries for their high capacity and low cost compared with graphite and most of other transition metal oxides. Porous carbon-free α-Fe2O3 films with two types of pore size distribution were prepared by electrostatic spray deposition, and they were characterized by X-ray diffraction, scanning electron microscopy and X-ray absorption near-edge spectroscopy. The 200°C-deposited thin film exhibits a high reversible capacity of up to 1080mAhg−1, while the initial capacity loss is at a remarkable low level (19.8%). Besides, the energy efficiency and energy specific average potential (E av) of the Fe2O3 films during charge/discharge process were also investigated. The results indicate that the porous α-Fe2O3 films have significantly higher energy density than Li4Ti5O12 while it has a similar E av of about 1.5V. Due to the porous structure that can buffer the volume changes during lithium intercalation/de-intercalation, the films exhibit stable cycling performance. As a potential anode material for high performance lithium–ion batteries that can be applied on electric vehicle and energy storage, rate capability and electrochemical performance under high-low temperatures were also investigated.
An electrochemical model for lithium polymer cells was developed and a parameter set for the model was measured using a series of laboratory experiments. Examples are supplied to demonstrate the capabilities of the electrochemical model to obtain the concentration, current, and potential distributions in lithium polymer cells under complex cycling protocols. The modeling results are used to identify processes that limit cell performance and for optimizing cell design. Extension of the electrochemical model to examine two-dimensional studies is also described.
Lead dioxide has electrical conductivity that is comparable to that of some of the metals. As a result like copper and nickel, lead dioxide can be deposited on non-conducting materials like polymers and ceramics using spontaneous and low cost deposition technique such as electroless deposition. This paper deals with development of conductive modacrylic fibers by coating them with lead dioxide via electroless deposition. The fibers so obtained will be used as additive in the lead-acid battery to improve its life and specific energy.