batterydata/paper-abstracts huggingface dataset:
One dimensional (1D) nanomaterials, which show tremendous potential in constructing high performance energy storage device, have gained considerable research interests. However the electrochemical reaction mechanism is still elusive. The most challenging issue in energy storage is developing insightful operando probes for the electrochemical processes. Notably, the in situ characterization of 1D nanomaterials is crucial to investigate the structural changes and uncover the intrinsic reasons for the capacity fading. Therefore numerous in situ characterization methods have been developed, such as in situ electron microscopy, X-ray detection techniques, spectroscopic techniques, nuclear magnetic resonance techniques, etc. Recent developments on in situ characterization technologies are summarized in this review. Different energy storage devices are involved, including Li-ion batteries, Na-ion batteries, supercapacitors, Li–air batteries and Li–S batteries. A new type of energy storage device, single nanowire device, has been also emphasized in this article. The reported highlights and developments are further discussed in details according to their reaction mechanisms. Through in situ characterization, no completely reversible volume expansion and phase transformation were observed during the lithiation and delithiation process. More structural/morphological damage and different electrochemical mechanisms were caused by the replace of lithium ions with sodium ions. The electron/hole doping of electric double layer capacitive materials and oxidation state of pseudocapacitive materials were focused. The growth and decomposition process of Li2O2 and polysulfide were also observed. The optimization mechanisms, including coating and doping of high conductivity materials, were proved to increase the electric/ion conductivity and reduce the cracks. The above mentioned results indicated that 1D nanomaterials with continuous ion/electron channels and short diffusion distance for electrolyte ions showed superior structural stability. Finally, the challenges and perspectives of the in situ characterization of 1D nanomaterials during electrochemical processes are emphasized as the conclusion.
Layered transition metal oxides are considered to be promising candidates as cathode materials for sodium-ion batteries. Herein, a facile solid-state reaction is developed to synthesize hexagons plate-like Na0.67Ni0.25Mn0.75O2+δ (denoted as P2-NNM) material with habit plane formed. The structure of this layered oxide is characterized by XRD, HR-TEM and SAED. The layered material delivers a high reversible capacity of 91.8 mAh g−1 at 0.2 C with a capacity retention of 94.4 % after 280 cycles, superior rate capability and long cycle life (84.2 % capacity retention after 1000 cycle). Ni2+ is an active ion and Ni doping alleviates the Jahn-Teller distortion, and Mn3+/Mn4+ coexist as Mn4+ is desired from the stability perspective. Particularly, CV and XPS results confirm these results. Moreover, the electrode exhibits a quasi-solid-solution reaction during the sodium extraction and insertion. This contribution demonstrates that P2-NNM is a promising cathode electrode for rechargeable long-life sodium-ion batteries.
The quantities of e-waste are expected to increase sharply in Chile. The purpose of this paper is to provide a quantitative data basis on generated e-waste quantities. A material flow analysis was carried out assessing the generation of e-waste from computer equipment (desktop and laptop PCs as well as CRT and LCD-monitors). Import and sales data were collected from the Chilean Customs database as well as from publications by the International Data Corporation. A survey was conducted to determine consumers’ choices with respect to storage, re-use and disposal of computer equipment. The generation of e-waste was assessed in a baseline as well as upper and lower scenarios until 2020. The results for the baseline scenario show that about 10,000 and 20,000tons of computer waste may be generated in the years 2010 and 2020, respectively. The cumulative e-waste generation will be four to five times higher in the upcoming decade (2010–2019) than during the current decade (2000–2009). By 2020, the shares of LCD-monitors and laptops will increase more rapidly replacing other e-waste including the CRT-monitors. The model also shows the principal flows of computer equipment from production and sale to recycling and disposal. The re-use of computer equipment plays an important role in Chile. An appropriate recycling scheme will have to be introduced to provide adequate solutions for the growing rate of e-waste generation.
Many lithium-ion batteries have electrodes made of multiple types of active materials in order to take advantage of each active material. According to the types and blending ratios of constituting active materials, there can be numerous combinations of blended-electrodes, resulting in different performance characteristics. This paper introduces how to numerically model lithium-ion batteries with blended-electrodes, and predict their performance. Further, this paper demonstrates how to apply the developed model to designing new batteries. First, we propose an equilibrium model which can predict equilibrium characteristics of a blended-electrode. Second, a physics-based lithium-ion cell model with blended-electrodes is proposed. Developed model is validated with experimental data and shows good agreements.
In this study, the application of neutron powder diffraction on studying the time-resolved structural evolution of a cell comprised with LiNi0.5Mn1.5O4 cathode and Li4Ti5O12 anode during charge–discharge cycling is demonstrated. As expected, the lattices of the LiNi0.5Mn1.5O4 cathode and the Li4Ti5O12 anode in the cell are found to simultaneously contract during charging and expand during discharging. It is found that for the LiNi0.5Mn1.5O4 cathode a solid-solution reaction is associated with the lattice change and the Ni2+/Ni3+ redox couple between 3.06 and 3.16 V (vs. Li4Ti5O12), and a two-phase reaction between Li x Ni0.5Mn1.5O4 and Ni0.25Mn0.75O2 is corresponding to the Ni3+/Ni4+ redox couple at voltage higher than 3.22 V (vs. Li4Ti5O12) without a corresponding change in lattice. The oxidation states of the metals in the electrodes are determined by tracking the associated change in the oxygen position. In addition, the Ti oxidation state is correlated to the intensity of the Li4Ti5O12 222 reflection at the anode, and the determined oxidation state of the Ni is correlated to the lithium occupancy within the cathode. Furthermore, the small volume changes of the cathode and the anode upon cycling suggest that the cell chemistry is favorable for practical applications.
A number of iodide-based electrolytes (LiCl–LiI, LiI–KI, LiCl–LiBr–LiI, LiCl–LiI–KI and LiF–LiCl–LiI) were considered to be used in thermal batteries. Ionic conductivity of multi-cation and all-lithium electrolytes were evaluated. They were compared to the classical electrolytes (LiCl–KCl, LiF–LiBr–KBr and LiF–LiCl–LiBr) used in thermal battery applications. Measurements were realised by electrochemical impedance spectroscopy (E.I.S.). It was shown that some all-lithium iodide-based electrolytes exhibit interesting ionic conductivities and are suitable as electrolytes in thermal batteries. It was pointed out that activation energy E a was close to 11 kJ mol−1 for multi-cation electrolytes, whereas it was equal to 7 kJ mol−1 for all-lithium electrolytes.
Activated carbon modified by Radio Frequency (RF) plasma at different power levels, times and volume flow rates of oxygen was prepared for activated carbon electrodes. Electrochemical characterization of different activated carbon electrodes was carried out using cyclic voltammetry (CV) with different electrolytes at a concentration of 0.1 M. A maximum capacitance of 38.9 F g−1 was obtained in a 0.1 M H2SO4 solution for the activated carbon (precursor material: coconut shell made in Japan) with plasma treatment conditions: power = 300 W, time = 3 min, and volume flow rates of oxygen = 45 sccm (standard cubic centimeter per minute). In addition, specific surface areas/pore-size distributions, functional groups, and surface morphologies of activated carbon with/without plasma treatment were examined by gas adsorption meter, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM), respectively.
US-based PolyFuel Inc, a specialist in fuel cell technology, particularly engineered membranes, has developed the first functional version of its prototype power supply for notebook-class computers. It can provide continuous non-stop run-times using small cartridges of methanol fuel that can be swapped by the user while the computer continues to run.
Mutations in postsynaptic scaffolding genes contribute to autism, thus suggesting a role in pathological processes in neurodevelopment. Recently, two de novo mutations in SHANK3 were described in schizophrenia patients. In most cases, abnormal SHANK3 genotype was also accompanied by cognitive disruptions. The present study queries whether common SHANK variants may also contribute to neuropsychological dysfunctions in schizophrenia. We genotyped five common coding or promoter variants located in SHANK1, SHANK2 and SHANK3. A comprehensive test battery was used to assess neuropsychological functions in 199 schizophrenia patients and 206 healthy control subjects. In addition, an independent sample of 77 subjects at risk for psychosis was analyzed for replication of significant findings. We found the T allele of the SHANK1 promoter variant rs3810280 to lead to significantly impaired auditory working memory as assessed with digit span (12.5 ± 3.6 vs. 14.8 ± 4.1, P < .001) in schizophrenia cases, applying strict Bonferroni correction for multiple testing. This finding was replicated for forward digit span in the at-risk sample (7.1 ± 2.0 vs. 8.3 ± 2.0, P = .044). Previously, altered memory functions and reduced dendritic spines and postsynaptic density of excitatory synapses were reported in SHANK1 knock-out mice. Moreover, the atypical neuroleptic clozapine was found to increase SHANK1 density in rats. Our findings suggest a role of SHANK1 in working memory deficits in schizophrenia, which may arise from neurodevelopmental changes to prefrontal cortical areas.
The present work demonstrates that lithium ions can be stepwise substituted by protons from spinel Li4Ti5O12 crystalline particles though simple ion-exchange in aqueous HCl solution with the aid of heat treatment. This enables us to continuously tune the Li-to-Ti stoichiometric ratios from 0.80 to 0.59, 0.41, 0.21, 0.15, and 0.09, thus transforming Li4Ti5O12 to Li4−xTi5O12 nanocrystals. The resulting nanocrystals maintain the spinel crystal structure when x becomes smaller than 3. Among as-prepared the Li4−xTi5O12 crystalline particles, Li1Ti5O12 shows the highest capacity of 193 mAh g−1 at 1C and 148 mAh g−1 at 20C, lower current impedance (47 Ω), significantly improved rate capability and fairly long cycle life. This excellent electrochemical performance makes spinel Li4−xTi5O12 particles as a promising anode candidate for lithium ion batteries superior.
This paper describes a new and economic route for the formation of three dimensional (3D) microstructured battery electrodes using our “in house” developed dip–spin coating technique for depositing layers of active material onto reticulated vitreous carbon (RVC) substrates. These coatings are optimized composite materials containing carbon black and polymer binder to facilitate good electronic and ionic conductivities through the electrode. The application process begins by immersing the substrate in an ink followed by rapid spinning to provide a uniform coating with a well controlled mass loading. The performance of the electrodes was investigated in lithium ion cells as a function of the composition of the inks used and the number of dip–spin coating cycles. Optimization of the ink composition, dip and spin parameters has improved the electrochemical performances of the electrodes to give state of the art footprint area specific capacities (>1000 μA h cm−2) and high rate capabilities (nearly 50% degree of discharge at 25 C) in lithium half cells. This represents the first stage in the development of a full 3D microbattery system. Initial results have also shown the versatility of this approach in depositing other electrode materials by forming uniform layers of both TiO2 and LiMn2O4.
A device for solar energy storage and release based on a reversible chemical reaction is demonstrated. A highly soluble derivative of a (fulvalene)diruthenium (FvRu2) system is synthesized, capable of storing solar energy (110 J g−1) in the form of chemical bonds and then releasing it “on demand”, when excited thermally or catalytically. A microfluidic device is designed and constructed for both the photo-harvesting and the heat-utilization steps, allowing for the recycling of material.
An eco-efficient approach bases on a mechano-chemical liquid-phase activation technique is developed for synthesizing LiMnPO4/C composites. The fine sized [Mn3(PO4)2·xH2O + Li3PO4] precursors with uniform particle size distribution are prepared, and characterized by XRD and scanning electron microscope (SEM). The in—situ carbon coated LiMnPO4 composites are synthesized by one-step solid state reaction. The prepared LiMnPO4/C nano-composites show a comparable rate capability with discharge specific capacity of 136.4 mAh g−1 at 0.05 C-rate and 118 mAh g−1 at 1 C-rate at room temperature. The results indicate that LiMnPO4/C composites synthesize from this environmental friendly route shows a promising electrochemical activity as cathode material for lithium ion batteries.
The partitioning of ecosystem respiration (ER) into plant respiration (PR), aboveground-part respiration (AGR), root respiration (RR), and microbial respiration (MR) components is crucial for understanding the responses of carbon cycling in terrestrial ecosystems to climate change. Here, we present the ER–PB/AGB regression method, which is a modification of the SR–BGB method (PB, plant biomass; AGB, aboveground biomass; SR, soil respiration; BGB, belowground biomass) and is based on the assumption of a linear relationship between biomass and respiration rate for the partitioning of ER into PR, AGR, RR, and MR. Diurnal measurements of CO2 flux and biomass analysis were conducted in three Kobresia (Kobresia pygmaea, Kobresia humilis, and Kobresia tibetica) meadows on the Qinghai-Tibetan Plateau. We found significant linear relationships between ER and PB/AGB in the three meadows. However, the relationships between measured SR and BGB were either not significant or lower than those between ER and PB/AGB. The relative contributions of respiration components (AGR, RR, MR) to ER decreased consistently in the order AGR>MR>RR in the three Kobresia meadows. The contributions of RR and MR to SR calculated by the proposed ER–PB/AGB method differed widely among the three meadows and were consistently higher (RR) and lower (MR) than those by the SR–BGB method in all three meadows. Compared with the SR–BGB technique, our ER–PB/AGB regression method proved capable of determining more accurately the temporal changes in a larger number of respiration components.
The effect and mechanism of Zn(II) on improving the performances of lead-acid cell with electrochemical active carbon (EAC) in negative mass is investigated. The hydrogen evolution of the cell is significantly reduced due to the deposition of Zn on carbon surface and the increased porosity of negative mass. Zn(II) additives can also improve the low-temperature and high-rate capacities of the cell with EAC in negative mass, which ascribes to the formation of Zn on lead and carbon surface that constructs a conductive bridge among the active mass. Under the co-contribution of EAC and Zn(II), the partial-state-of-charge cycle life is greatly prolonged. EAC optimizes the NAM structure and porosity to enhance the charge acceptance and retard the lead sulfate accumulation. Zn(II) additive reduces the hydrogen evolution during charge process and improves the electric conductivity of the negative electrode. The cell with 0.6 wt% EAC and 0.006 wt% ZnO in negative mass exhibits 90% reversible capacity of the initial capacity after 2100 cycles. In contrast, the cell with 0.6 wt% EAC exhibits 84% reversible capacity after 2100 cycles and the control cell with no EAC and Zn(II) exhibits less than 80% reversible capacity after 1350 cycles.
Electroactive materials with high electrochemical activity, good rate capability and excellent cycling stability are urgently needed for hybrid supercapacitors, but achieving those performances at the same time is still a big challenge. Here, α phase nickel−cobalt−manganese hydroxide (NiCoMn−OH) with a flower-like structure is synthesized and used as the battery materials for hybrid supercapacitor. The NiCoMn−OH exhibits strong synergetic electrochemistry between the transition metals, which contributes better charge storage performances. The NiCoMn−OH shows a specific capacity of 757 C g−1 at 1 A g−1 and retains 369 C g−1 at very high specific current of 50 A g−1, which are both much higher than the corresponding bimetal and nomometal hydroxides. Therefore, both high electrochemical activity and rate capability have been achieved. The α phase NiCoMn−OH also exhibits a long-term cycling stability because the specific role of Co, maintaining 100% of the specific capacity after 1200 cycles. The hybrid supercapacitor based on NiCoMn−OH also shows high specific capacity of 219 C g−1 at 1 A g−1, high rate performance of 53% capacity retention when the specific current increases 25 times and ultralong cycling stability of 83% capacity retention after 12,000 cycles.
Schizophrenia is a severe psychiatric illness with widespread impairments of cognitive functioning; however, a certain percentage of subjects are known to perform in the normal range on neuropsychological measures. While the cognitive profiles of these individuals have been examined, there has been relatively little attention to the neuroanatomical characteristics of this important subgroup. The aims of this study were to statistically identify schizophrenia subjects with relatively normal cognition, examine their neuroanatomical characteristics relative to their more impaired counterparts using cortical thickness mapping, and to investigate relationships between these characteristics and demographic variables to better understand the nature of cognitive heterogeneity in schizophrenia. Clinical, neuropsychological, and MRI data were collected from schizophrenia (n=79) and healthy subjects (n=65). A series of clustering algorithms on neuropsychological scores was examined, and a 2-cluster solution that separated subjects into neuropsychologically near-normal (NPNN) and neuropsychologically impaired (NPI) groups was determined most appropriate. Surface-based cortical thickness mapping was utilized to examine differences in thinning among schizophrenia subtypes compared with the healthy participants. A widespread cortical thinning pattern characteristic of schizophrenia emerged in the NPI group, while NPNN subjects demonstrated very limited thinning relative to healthy comparison subjects. Analysis of illness duration indicated minimal effects on subtype classification and cortical thickness results. Findings suggest a strong link between cognitive impairment and cortical thinning in schizophrenia, where subjects with near-normal cognitive abilities also demonstrate near-normal cortical thickness patterns. While generally supportive of distinct etiological processes for cognitive subtypes, results provide direction for further examination of additional neuroanatomical differences.
In this paper, a genetic algorithm is developed in which each individual is represented not by a string but by a matrix: in this way the entire population is represented by a 3-D matrix. Such a representation is particularly useful for solving optimization problems with many discrete variables: such as, for example, the optimal allocation and sizing of distributed generation systems or the optimal compensation in a distribution system through the installation, in a prefixed number of nodes, of batteries of fixed or modulated capacitors, having different sizes. In these cases, the unknowns of the optimization process are the nodes where the apparatus can be installed and their rated sizes to be chosen in a discrete set of values. The adopted representation allows setting up a group of new operators whose application implies a strong increase of the search space size and consequently the number of algorithm parameters increases as well. The primary objective of this paper is that of evaluating the algorithm’s performance and, with this aim, it has been applied to the problem of the compensation of electrical distribution networks.
A uniform Co3O4 layer is coated on nickel-rich cathode material LiNi0.6Co0.2Mn0.2O2 via a facile polyvinyl pyrrolidone (PVP)-assisted wet coating process. The 1wt.% Co3O4-coated LiNi0.6Co0.2Mn0.2O2 shows improved electrochemical performance, especially the cycling stability, at high cut-off voltage of 4.6V. Its highly continuous and compact coating layer is confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The improved performance can be attributed to Co3O4 coating layer which acts as HF scavenger and protects LiNi0.6Co0.2Mn0.2O2 core from electrolyte attack. Cyclic voltammetry (CV) results indicate that the coated sample exhibits lower polarization and higher reversibility of electrode reaction. The storage property of LiNi0.6Co0.2Mn0.2O2 is also ameliorated by Co3O4 coating. After storing in air for three months, the initial discharge capacities of pristine and 1wt.% Co3O4-coated LiNi0.6Co0.2Mn0.2O2 decrease from 206.4mAhg−1 and 209.5mAhg−1 at 0.1C (18mAg−1) to 177.8mAhg−1 and 198.6mAhg−1, respectively. Electrochemical impedance spectroscopy (EIS) results reveal that the charge transfer resistance of coated sample after storage is much smaller than that of stored pristine sample. The improved storage property also benefits from Co3O4 coating layer which can prevent the formation of electrochemical inactive Li2CO3/LiOH impurities.
Objective: The aim of this article was to provide a survey of the clinical development of pharmacotherapy for Alzheimer's disease (AD). Methods: A search of PubMed to identify pertinent English-language literature was conducted using the terms Alzheimer's disease AND clinical trials (2003–2008), dementia AND prevention AND clinical trials (2003–2008), and the chemical names of all compounds mentioned in articles on new drugs for AD published since 2005. www.ClinicalTrials.gov was searched for relevant trials. Abstracts of the 2008 International Conference on Alzheimer's Disease (ICAD) were reviewed for relevance, as were pharmaceutical company and AD advocacy Web sites. Articles selected for review were primary reports of data from preclinical studies and clinical trials. Results: A large number of drugs with differing targets and mechanisms of action are under development for the treatment of AD. Phase III trials of Ginkgo biloba, NSAIDs, phenserine, statins, tarenflurbil, tramiprosate, and xaliproden have been completed, none of them demonstrating adequate efficacy. Encouraging results from completed Phase II trials of dimebon, huperzine A, intravenous immunoglobulin, and methylthioninium chloride were reported at ICAD 2008. Nineteen compounds are currently in Phase II trials, and 3 compounds (AN1792, lecozotan SR, and SGS742) failed at this stage of development. Conclusions: Despite disappointing results from recently completed Phase III trials of several novel compounds, the extent and breadth of activity at all phases of clinical development suggest that new pharmacotherapeutic options for the treatment of AD will become available within the next decade.