batterydata/paper-abstracts huggingface dataset:
Electrochemical storage of energy is a necessary asset for the integration of intermittent renewable energy sources such as wind and solar power into a complete energy scenario. Redox flow batteries (RFBs) are the only type of battery in which the energy content and the power output can be scaled independently, offering flexibility for applications such as load levelling. However, the prevailing technology, the all Vanadium system, comprises low energy and low power densities. In this study we investigate two polyoxometalates (POMs), [SiW12O40]4− and [PV14O42]9−, as nano-sized electron shuttles. We show that these POMs exhibit fast redox kinetics (electron transfer constant k0 ≈ 10−2 cm s−1 for [SiW12O40]4−), thereby enabling high power densities; in addition, they feature multi-electron transfer, realizing a high capacity per molecule; they do not cross cation exchange membranes, eliminating self-discharge through the separator; and they are chemically and electrochemically stable as shown by in situ NMR. In flow battery studies the theoretical capacity (10.7 A h L−1) could be achieved under operating conditions. The cell was cycled for 14 days with current densities in the range of 30 to 60 mA cm−2 (155 cycles). The Coulombic efficiency was 94% during cycling. Very small losses occurred due to residual oxygen in the system. The voltage efficiency (∼65% at 30 mA cm−2) was mainly affected by ohmic rather than kinetic losses. Pathways for further improvement are discussed.
Publisher Summary This chapter provides the background for renewable energy sources and describes their occurrence, devices for using them, and the role of renewable energy in current and future energy systems, depending on social values and the economic rules used to judge the viability of competing solutions. It discusses the status of renewable energy development in the context of current political focus. Several economists have addressed whether it is cheaper to let the impacts of global warming happen and then try to reduce the consequences than to avoid the impacts. Arguments for the marginal cost advantage of adaptation as compared to abstract reference to mitigation appear even more suspect when one considers the energy efficiency measures not implemented. Several studies have shown that energy demands could be reduced by about a factor of four by efficiency measures fully available and costing less than the energy they displace, rendering exactly the same energy service to the user. The intermittency of several renewable energy flows makes it imperative to include features in systems relying on renewable energy inputs that can ensure supply–demand matching in time and place. This brings into focus bulk storage development, as well as means for transmission to and from such devices, and between load locations and supply locations, especially when the closest ones may be unavailable.
This study investigates the effect of 50-kW (about 2C) direct current fast charging on a full-size battery electric vehicle's battery pack in comparison to a pack exclusively charged at 3.3 kW, which is the common alternating current Level 2 charging power level. Comparable scaled charging protocols are also independently applied to individual cells at three different temperatures, 20 °C, 30 °C, and 40 °C, to perform a comparative analysis with the packs. Dominant cell-level aging modes were identified through incremental capacity analysis and compared with full packs to gain a clear understanding of additional key factors that affect pack aging. While the cell-level study showed a minor impact on performance due to direct current fast charging, the packs showed a significantly higher rate of capacity fade under similar charging protocols. This indicates that pack-level aging cannot be directly extrapolated from cell evaluation. Delayed fast charging, completing shortly before discharge, was found to have less of an impact on battery degradation than conventional alternating current Level 2 charging.
The efficiency of cooling plates for electric vehicle batteries can be improved by optimizing the geometry of internal fluid channels. In practical operation, a cooling plate is exposed to a range of operating conditions dictated by the battery, environment, and driving behaviour. To formulate an efficient cooling plate design process, the optimum design sensitivity with respect to each boundary condition is desired. This determines which operating conditions must be represented in the design process, and therefore the complexity of designing for multiple operating conditions. The objective of this study is to determine the influence of different operating conditions on the optimum cooling plate design. Three important performance measures were considered: temperature uniformity, mean temperature, and pressure drop. It was found that of these three, temperature uniformity was most sensitive to the operating conditions, especially with respect to the distribution of the input heat flux, and also to the coolant flow rate. An additional focus of the study was the distribution of heat generated by the battery cell: while it is easier to assume that heat is generated uniformly, by using an accurate distribution for design optimization, this study found that cooling plate performance could be significantly improved.
Charging a commercial lithium-ion battery intercalates lithium into the graphite-based anode, creating various lithium carbide structures. Despite their economic importance, these structures and the dynamics of their charging-discharging transitions are not well-understood. We have videoed single microcrystals of high-quality, natural graphite undergoing multiple lithiation-delithation cycles. Because the equilibrium lithium-carbide compounds corresponding to full, half, and one-third charge are gold, red, and blue respectively, video observations give direct insight into both the macromolecular structures and the kinematics of charging and discharging. We find that the transport during the first lithiation is slow and orderly, and follows the core-shell or shrinking annuli model with phase boundaries moving at constant velocities (i.e. non-diffusively). Subsequent lithiations are markedly different, showing transport that is both faster and disorderly, which indicates that the initially pristine graphite is irreversibly and considerably altered during the first cycle. In all cases deintercalation is not the time-reverse of intercalation. These findings both illustrate how lithium enters nearly defect-free host material, and highlight the differences between the idealized case and an actual, cycling graphite anode.
The 0.3Li2MnO3·0.7Li[Mn0.60Ni0.25Co0.15]O1.975F0.025 cathode materials were synthesized by using a co-precipitation process in a Couette-Taylor reactor. Fluorine was substituted to facilitate the movement of lithium ions by forming more compact SEI layer and reduce the dissolution of transition metals, and lower internal impedance with charging/discharging cycling. In order to chemically remove the Li2O, the 0.3Li2MnO3·0.7Li [Mn0.60Ni0.25Co0.15]O1.975F0.025 composites was preconditioned by a HNO3 solution. The acid-treated 0.3Li2MnO3·0.7Li[Mn0.60Ni0.25Co0.15]O1.975F0.025 was showed the low initial irreversible capacity and the higher discharge capacity. The acid-treated and fluorine-substituted materials delivered the low initial discharge capacities, but it gradually increased during cycles.
Na-birnessite-type MnO2 (Na-OL-1) nanoplates and sodium manganese dioxide nanobelts with a 2×4 tunnel (Na-OMS-5) were synthesized by a hydrothermal method via one-pot oxidation reaction at 120 and 200°C, respectively. The microstructure, morphology, and thermal stability of the MnO2 products were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, simultaneous thermogravimetric-mass spectrometry, and N2 adsorption–desorption measurements. Their electrochemical performance was investigated in order to understand the sodium ions intercalation−deintercalation processes in the lamellar or tunnel structure of MnO2. Na-OL-1 nanoplates exhibited a specific capacitance of 308 F g−1 at a current density of 0.2 A g−1, which is much higher than that of Na-OMS-5 nanobelts (141 F g−1). Moreover, the Na-OL-1 nanoplates showed a good rate capability and electrochemical stability, suggesting that it is a promising electrode material for supercapacitors.
A new hyperbranched multi-arm star polymer with hyperbranched polystyrene (HBPS) as core and polymethyl methacrylate-block-poly(ethylene glycol) methyl ether methacrylate(PMMA-b-PPEGMA) as arms was firstly synthesized by atom transfer radical polymerization. The obtained hyperbranched multi-arm star polymer (HBPS-(PMMA-b-PPEGMA)x) exhibited good thermal stability with a thermal decomposition temperature of 372°C. The transparent, free-standing, flexible polymer electrolyte film of the blending of HBPS-(PMMA-b-PPEGMA)x and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) was successfully fabricated by a solution casting method. The ionic conductivity of the hyperbranched star polymer electrolyte with a molar ratio of [EO]/[Li] of 30 could reach 8.3×10−5 Scm−1 at 30°C (with the content of PPEGMA of 83.7%), and 2.0×10−4 Scm−1 at 80°C (with the content of PPEGMA of 51.6%). The effect of the concentration of lithium salts on ionic conductivity was also investigated. The obtained all-solid-state polymer electrolyte possessed a wide electrochemical stability window of 4.7V (vs. Li+/Li), and a lithium-ion transference number (tLi + ) up to 0.31. The interfacial impedance of the fabricated Li│polymer electrolyte│Li symmetric cell based on hyperbranched star multi-arm polymer electrolyte exhibited good interfacial compatibility between all-solid-state polymer electrolyte and electrodes. The excellent properties of the hyperbranched star polymer electrolyte made it attractive as solid-state polymer electrolyte for lithium-ion batteries.
Allocentric and egocentric memory was investigated in patients with Huntington's disease (HD) and matched controls. Patients with HD and age- and education-matched healthy normal controls (NC) were administered two visuospatial recognition memory tasks, one assessing memory for hand positions (egocentric) and the other assessing memory for spatial locations (allocentric). HD patients showed normal primacy and recency effects, but their overall performance was impaired relative to controls on both tasks. Correlation analyses indicated that HD patients' performance on the Hand Position Memory task, but not the Spatial Location Memory task, was associated with global cognitive status (Mattis Dementia Rating Scale) and disease severity (Shoulson and Fahn Rating Scale), and HD patients' performances on the two tasks were not associated. Results provide preliminary support for the role of the caudate nucleus in both allocentric and egocentric spatial memory.
In this study, a new class of contenders for high-voltage and high-capacity positive electrode materials with the composition Na x Li0.7−x Ni1−y MnyO2 (0.03 < x ≤ 0.25, 0.5 ≤ y ≤ 0.8) was synthesized by thermal treatment; these positive electrode materials synthesized by Na+/Li+ exchange using P3Na0.7Ni1−y Mn y O2 (0.5 ≤ y ≤ 0.8) as the precursor exhibited a mixture of layered and spinel structures. The (dis)charge voltage-capacity curve of materials with these compositions significantly varied according to the residual Na and Mn content. Notably, HT-Na x Li0.7−x Ni1−y Mn y O2 (x = 0.093, y = 0.67) exhibited a maximum discharge capacity of 261 mA h g−1 at an average voltage of 3.36 V at 25 °C (between 2.0 and 4.8 V), which translates to an energy density of 943 W h kg−1. The obtained electrochemical performance is rationalized by the phase fractions of layered and spinel structures, which is triggered by the residual Na and Mn content in Na x Li0.7−x Ni1−y Mn y O2.
Urban freight vehicles significantly impact the urban environment due mainly to traffic congestion, reduction in road capacity and pollutant emissions. Introducing low emission vehicles is one of the major measures foreseen in alleviating negative externalities. In this context, city logistics may represent a market niche for the deployment of electric vehicles. This paper introduces a methodology based on the Systems of Innovation approach to examine the process by which electric vehicles may be introduced in city logistics. The proposed methodology considers the complex interactions between actors and institutions and proposes a Systems' of Innovation Framework, which combines in a matrix the actors, the mechanisms and market conditions providing an instrument by which to qualitatively assess the current status and estimate future requirements and pre-conditions for innovation uptake. Applied to the case of electric vehicles in city logistics, the proposed framework is used to examine “who” should act, “how to act”, “what to act upon” and “when” to intervene. Findings indicate the need to transfer leadership from central authorities to municipal authorities in order to move from the initiation stage to the implementation stage. The importance of strong networks between innovation actors and respective building of capacities is considered of importance.
The electrochemical, X-ray diffraction, thermal, rheological and spectroscopic studies have been carried out to examine the effect of nanosized TiO2 addition in different concentration to polymethylmethacrylate (PMMA) based gel polymer electrolytes (GPE). This work demonstrates that with optimum concentration of TiO2 loadings in GPE, the ionic conductivity enhances with negligible effect on other electrochemical properties. The obtained ionic conductivity value is >10−3 Scm−1. An increase in viscosity by an order of magnitude is obtained which also restricts the flow property of GPE. The addition of TiO2 retains the amorphicity of the GPE while the T g increases. Enhanced mechanical stability of these composite polymer electrolytes (CPEs) with solid-like behavior is evident from their appearance. The activation energy has been calculated by fitting the conductivity profile in VTF equation, which decreases on the addition of fillers. FTIR characterization also confirms the interaction of filler with CO of PMMA. The capabilities and properties exhibited by these CPEs will be of immense interest for electrochemists to use them in solid-state devices.
Pharmacological evidence associates type I dopamine receptors, including subtypes D1 and D5, with learning and memory. Analyses using genetic approaches have determined the relative contribution of dopamine receptor D1 (D1R) in cognitive tasks. However, the lack of drugs that can discriminate between D1R and D5R has made the pharmacological distinction between the two receptors difficult. Here, we aimed to determine the role of D5R in learning and memory. In this study we tested D5R knockout mice and wild-type littermates in a battery of behavioral tests, including memory, attention, locomotion, anxiety and motivational evaluations. Our results show that genetic deficiency of D5R significantly impairs performance in the Morris water maze paradigm, object location and object recognition memory, indicating a relevant role for D5R in spatial memory and recognition memory. Moreover, the lack of D5R resulted in decreased exploration and locomotion. In contrast, D5R deficiency had no impact on working memory, anxiety and depressive-like behavior, measured using the spontaneous alternation, open-field, tail suspension test, and forced swimming test. Electrophysiological analyses performed on hippocampal slices showed impairment in long-term-potentiation in mice lacking D5R. Further analyses at the molecular level showed that genetic deficiency of D5R results in a strong and selective reduction in the expression of the NMDA receptor subunit NR2B in the hippocampus. These findings demonstrate the relevant contribution of D5R in memory and suggest a functional interaction of D5R with hippocampal glutamatergic pathways.
The specific capacity and cycling stability of lithium sulfur batteries have been investigated with respect to the chemical composition and fabrication process of the sulfur electrode. Three different kinds of electrode compositions (containing Nafion, polyacrylonitrile/carboxymethylcellulose, and Teflon, respectively, as binder materials) have been tested. For the electrodes containing Nafion as the binder material, an additional Nafion coating has been deposited on top of the electrodes to enhance the sulfur retention and to suppress the polysulfide shuttle. Both SEM images before cycling and post mortem are presented in order to shed light on the influence of the composition of the electrode on its electrochemical performance. Good cycling performance can be attained based on relatively simple and therefore cost-effective electrode setups and production methods.
We report on a 1-year continuous precipitation sampling record from an alpine site and a rural site in the Urumqi River Valley, East Tien Shan, China. The 128 samples, collected from April 2003 to February 2004, at two sites were analyzed for the major inorganic ions, pH, electrical conductivity and insoluble microparticles. The precipitation was typically alkaline with a volume-weighted mean pH of 6.99 and 7.27 at the alpine site and the rural site, respectively. Ca2+ was the dominant cation, and SO4 2− was the dominant anion. The precipitation chemistry in this region was mainly controlled by regional Asian dust storms, local dust and anthropogenic activities. The relative impact of anthropogenic activities, specifically uncontrolled coal combustion, was larger at the rural site compared to the alpine monitoring site.
This paper reviews carbon-based nanostructured materials as electrodes in electrochemical capacitors and distinguishes the carbon-based electrode materials according to their primary applications. They are broadly discussed and categorized into three groups based on their specified energy storage device applications: (1) industrial and stationary applications, (2) automotive and transportation applications, and (3) portable and personal electronics applications. Different carbon-based nanostructured electrodes were discussed from different perspectives, such as energy density, power density, reliability, safety, and cost. The basic principles, characteristics, various performance, and features of the supercapacitors to meet the requirements of different applications were analyzed. The future trend of electrochemical capacitors was discussed.
Lithium ion batteries are commonly employed in hybrid electric vehicles and achieving high energy density in the battery has been among the most critical issues in the automotive industry. Since thermal management is very important in the automotive batteries with layout limitation, a design strategy for effective cooling should be carefully opted. Particularly, a forced air cooling has been considered as a practical option in the automotive industry. In this article, a specific design of air-cooled battery system is theoretically investigated and numerically modelled to satisfy the required thermal specifications. Since a typical battery system in hybrid electric vehicles consists of the stacked multiple battery cells, cooling performance is determined mainly by the uniform distribution of air flow in the coolant passage which dissipates heat generated from the battery cells. It is demonstrated that the required cooling performance can be achieved by employing the tapered manifold and pressure relief ventilation even without changing the layout/design of the existing battery system. Furthermore, a theoretical analysis is performed as a design guideline to enhance the cooling performance.
High quality graphene sheets were prepared from graphite powder through oxidation followed by rapid thermal expansion in nitrogen atmosphere. The preparation process was systematically investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and Brunauer–Emmett–Teller (BET) measurements. The morphology and structure of graphene sheets were characterized by scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HRTEM). The electrochemical performances were evaluated in coin-type cells versus metallic lithium. It is found that the graphene sheets possess a curled morphology consisting of a thin wrinkled paper-like structure, fewer layers (∼4 layers) and large specific surface area (492.5m2 g−1). The first reversible specific capacity of the prepared graphene sheets was as high as 1264mAhg−1 at a current density of 100mAg−1. Even at a high current density of 500mAg−1, the reversible specific capacity remained at 718mAhg−1. After 40 cycles, the reversible capacity was still kept at 848mAhg−1 at the current density of 100mAg−1. These results indicate that the prepared high quality graphene sheets possess excellent electrochemical performances for lithium storage.
The correct power supply for telecommunications relay stations, especially in areas where there is no electricity, is a handicap for operators to expand their clientele. It is on this sensitive topic that is taken this article. The photovoltaic solar energy appears as the most attractive solution: 1. To answer the energetic requires of a telecommunications base station. 2. To satisfy the needs of isolated uses, as is the case on many areas in our country. In this work, we study the best approach to transfer all the useful power from the photovoltaic generator to a telecommunications relay station (BTS or BSC). Knowing that the current–voltage characteristic of the generator (which depends on the illumination and temperature conditions), there is an operating point where the flowed power is on its maximum, the optimization consist of being permanently fixed on this point by acting automatically on the load made by the generator. This load adaptation is effected using a static converter including losses should be as low as possible, which can besides ensure a shaping function of the output rate (continuous–continuous conversion with voltage modification). We chose to use maximum power point MPPT research technology, based on different MPPT algorithms, controlled by a pulse-width modulation (PWM) signal. Modeling on Matlab/Simulink of the system different parts is proposed.
Objective Central cholinergic circuits of human brain can be tested non-invasively by coupling peripheral nerve stimulation with transcranial magnetic stimulation of motor cortex. This test, named short latency afferent inhibition (SAI) has been shown in healthy subjects to be sensitive to the blockage of muscarinic acetylcholine receptors and it is impaired in Alzheimer disease (AD) patients, a cholinergic form of dementia, while it is normal in non-cholinergic forms of dementia such as fronto-temporal dementia. The objective of present study was to evaluate central cholinergic circuits in patients with Vascular Dementia (VaD). Methods We evaluated SAI in a group of patients with VaD and compared the data with those from a group of AD patients and a control group of age-matched healthy individuals. Results Mean SAI was normal in VaD patients while it was significantly reduced in AD patients. The analysis of individual data showed abnormal SAI in 75% of AD and in only 25% of VaD. Conclusions SAI is normal in most of VaD patients in contrast with AD patients. This test might be used for the functional evaluation of central cholinergic circuits in VaD patients. Significance SAI testing may represent a useful additional tool for the evaluation of patients with VaD however, further studies are required in order to evaluate whether this method can be used for the differential diagnosis between pure VaD and different forms of dementia.