batterydata/paper-abstracts huggingface dataset:
Transition metal phosphides are promising anode materials for lithium ion batteries because of their abundant natural resources and high theoretical capacities. In this study, the electrochemical properties of LiFeP as an anode material for lithium ion battery were investigated for the first time. LiFeP powders were successfully synthesized by a conventional two-step solid-state reaction method. The results of X-ray powder diffraction and selected area electron diffraction revealed that the layered plate-like LiFeP was stacked by the (001) crystal plane. As an electrode material, LiFeP delivered a superior reversible capacity of 507 mA h g−1 at a high current density of 300 mA g−1 after 300 cycles and excellent rate performance. After cycling, the layered structure can be well maintained, which would be greatly beneficial to the electrochemical performance of LiFeP. The reason for the increase in capacity was also investigated and can be attributed to the high number of conversion reactions of LiFeP and the generation of elemental P during cycling.
In this work, Na2Li2Ti6O14 and its Li-site substitution Na2Li1.9M0.1Ti6O14 (Mn+ = Na+, Mg2+, Cr3+, Ti4+, V5+) samples are synthesized by a simple solid state reaction route and evaluated as anode materials for lithium-ion batteries. Their crystal structures and ion doping behaviors are described and verified by Rietveld refinement. Electrochemical results exhibit that Na+, Mg2+ and Cr3+ dopings can effectively improve the lithium storage capability of Na2Li2Ti6O14. Especially for Na2Li1.9Cr0.1Ti6O14, it shows the best cycling and rate properties among all the as-prepared samples, with a cycling reversible capacity of 262.2 mAh g−1 at 100 mA g−1 and a rate charge capacity of 233.3 mAh g−1 at 700 mA g−1. The enhanced electrochemical properties are contributed to the reduced particle size, decreased charge transfer resistance and improved ionic diffusion coefficient of Na2Li2Ti6O14 via Cr3+ doping. Furthermore, the zero-strain characteristic should also be responsible for the outstanding lithium storage capability of Na2Li1.9Cr0.1Ti6O14. Besides, in-situ X-ray diffraction also reveals that Na2Li1.9Cr0.1Ti6O14 has high structural stability and reversibility during charge–discharge process. Therefore, Na2Li1.9Cr0.1Ti6O14 may be a probable high performance anode material for lithium-ion batteries.
High-rate cathode materials for Li-ion batteries require fast Li transport kinetics, which typically rely on topotactic Li intercalation/de-intercalation because it minimally disrupts Li transport pathways. In contrast to this conventional view, here we demonstrate that the rate capability in a Li-rich cation-disordered rocksalt cathode can be significantly improved when the topotactic reaction is replaced by a non-topotactic reaction. The fast non-topotactic lithiation reaction is enabled by facile and reversible transition metal octahedral-to-tetrahedral migration, which improves rather than impedes Li transport. Using this concept, we show that high-rate performance can be achieved in Mn- and Ni-based cation-disordered rocksalt materials when some of the transition metal content can reversibly switch between octahedral and tetrahedral sites. This study provides a new perspective on the design of high-performance cathode materials by demonstrating how the interplay between Li and transition metal migration in materials can be conducive to fast non-topotactic Li intercalation/de-intercalations.
There is some uncertainty concerning the role of iron deposits on the surface of nickel electrodes with respect to electrode activity during alkaline water electrolysis. Iron deposits variously have been reported to enhance nickel electrode activity by providing additional surface area from electrolytic deposition of solution phase iron species or to depassivate nickel electrodes via a surface interaction effect. In this study, nickel electrodes were sputtered with a smooth iron layer to determine the effect of metallic iron on the electrode surface without significantly changing the electrode surface area. A permeation cell with 8mol/L KOH at 70°C was used to follow nickel electrode potentials during hydrogen evolution while the permeation current was used to detect changes in the electrode structure. Short term measurements reveal no difference in behavior of coated and non-coated electrodes. Longer term results showed that a metallic iron coating on nickel electrodes prevented deactivation of the electrodes. The deactivation effect was associated with an increased hydrogen flux through the electrodes indicative of an elevated hydrogen concentration at the electrode surface. This high surface concentration is concluded to be the result of nickel hydride phase formation at the surface of the nickel electrodes. The iron coating prevents this surface phase from forming and hence prevents deactivation of the electrode.
Experimental models of Alzheimer’s disease (AD) are critical to gaining a better understanding of pathogenesis and to assess the potential of novel therapeutic approaches. The most commonly used experimental animal models are transgenic mice that overexpress human genes associated with familial AD (FAD) that result in the formation of amyloid plaques. However, AD is defined by the presence and interplay of both amyloid plaques and neurofibrillary tangle pathology. The track record of success in AD clinical trials thus far has been very poor. In part, this high failure rate has been related to the premature translation of highly successful results in animal models that mirror only limited aspects of AD pathology to humans. A greater understanding of the strengths and weakness of each of the various models and the use of more than one model to evaluate potential therapies would help enhance the success of therapy translation from preclinical studies to patients. In this review, we summarize the pathological features and limitations of the major experimental models of AD, including transgenic mice, transgenic rats, various physiological models of sporadic AD and in vitro human cell culture models.
The aim of this study was to assess the specific relation between 3- to 6-year-olds’ performance on a task measuring executive function (EF), the Dimensional Change Card Sort task (DCCS), and different developmental attainments in their theory of mind (ToM) by employing a battery of scaled ToM tasks that were comparable in task format and task demands. In addition, individual differences on the temperamental dimensions emotionality, activity, sociability, and shyness were assessed by parental rating. The main findings show that children’s (N =195) performance on the DCCS related to their overall performance on the ToM scale but that this relation was specific to those ToM tasks that tap children’s understanding of epistemic states such as knowledge access, diverse beliefs, and false beliefs regarding content and location. The relation between children’s EF and overall ToM performance remained significant after controlling for age, sentence comprehension, child temperament, and parental education. Individual differences in child activity showed consistent negative relation to EF and ToM abilities. The findings point to a differential involvement of the various EF components in reasoning about different mental concepts.
Five primary classes of drugs bear specific application to the LVAD population: (i) drugs that provide haemodynamic support; (ii) antimicrobials; (iii) anticoagulants and antiplatelets; (iv) agents that promote myocardial recovery; and (v) miscellaneous other medications. Drugs that provide haemodynamic support are subdivided into inotropes, vasopressors and pulmonary vasodilators. Some combination of these medications is usually administered within the perioperative period in order to maintain stable patient haemodynamics and assure proper LVAD function. Antimicrobials are of paramount importance in the pre-, intra- and postoperative periods to minimise the risk of infection, an unfortunately common complication of LVAD therapy that can have potentially morbid consequences. Anticoagulants and antiplatelet medications are necessary for certain types of LVADs and serve to curb the incidence of device thrombus formation and associated embolic phenomena. Pharmacotherapeutic agents that facilitate myocardial recovery are being investigated as adjuncts to LVAD support so that bridge to recovery can become a realistic outcome for a growing number of LVAD patients. The miscellaneous class of medications used with LVADs includes those that minimise the risk of bleeding in select patients and those that enhance proper vitamin and nutrient status in the postoperative period, the attainment of which may serve vital to a successful recovery.
The reaction mechanism of a high capacity lithium- and manganese-rich metal oxide, 0.4Li2MnO3–0.6LiMn0.5Ni0.5O2, has been investigated at the atomic level. High-resolution synchrotron X-ray powder diffraction (HRPD) and X-ray absorption spectroscopy (XAS) were used, respectively, to evaluate the electrochemical charge and discharge reactions in terms of local and bulk structural changes, and variations in the oxidation states of the transition metal ions. Ni K-edge XAS data indicate the participation of nickel in reversible redox reactions, whereas Mn K-edge absorption spectra show that the manganese ions do not participate in the electrochemical reactions. Rietveld refinements of the oxygen occupancy during charge and discharge provide evidence of reversible oxygen release and re-accommodation by the host structure; this unique oxygen participation is likely the main reason for the anomalously high capacity of these electrodes. The HRPD data also show that during the early cycles, characteristic peaks of the Li2MnO3 component disappear when charged to 4.7V, but reappear on discharge to 2.5V, consistent with a reversible lithium and oxygen extraction process. The results provide new insights into the charge compensation mechanisms that occur when high capacity, lithium- and manganese-rich electrode materials are electrochemically cycled – a topic that is currently being hotly debated in the literature.
Recent studies have asserted that self-reported learning gains (SRLG) are valid measures of learning, because gains in specific content areas vary across academic disciplines as theoretically predicted. In contrast, other studies find no relationship between actual and self-reported gains in learning, calling into question the validity of SRLG. I reconcile these two divergent sets of literature by proposing a theory of college student survey response that relies on the belief-sampling model of attitude formation. This theoretical approach demonstrates how students can easily construct answers to SRLG questions that will result in theoretically consistent differences in gains across academic majors, while at the same time lacking the cognitive ability to accurately report their actual learning gains. Four predictions from the theory are tested, using data from the 2006–2009 Wabash National Study. Contrary to previous research, I find little evidence as to the construct and criterion validity of SRLG questions.
Computational and experimental work directed at exploring the electrochemical properties of tetrahedrally coordinated Mn in the +5 oxidation state is presented. Specific capacities of nearly 700mAhg−1 are predicted for the redox processes of Li x MnO4 complexes based on two two-phase reactions. One is topotactic extraction of Li from Li3MnO4 to form LiMnO4 and the second is topotactic insertion of Li into Li3MnO4 to form Li5MnO4. In the experiments, it is found that the redox behavior of Li3MnO4 is complicated by disproportionation of Mn5+ in solution to form Mn4+ and Mn7+ and by other irreversible processes; although an initial capacity of about 275mAhg−1 in lithium cells was achieved. Strategies based on structural considerations to improve the electrochemical properties of MnO4 n− complexes are given.
Resource-limited tropical countries are home to numerous infectious pathogens of both human and zoonotic origin. A capability for early detection to allow rapid outbreak containment and prevent spread to non-endemic regions is severely impaired by inadequate diagnostic laboratory capacity, the absence of a “cold chain” and the lack of highly trained personnel. Building up detection capacity in these countries by direct replication of the systems existing in developed countries is not a feasible approach and instead requires “leapfrogging” to the deployment of the newest diagnostic systems that do not have the infrastructure requirements of systems used in developed countries.
Dendrite formation is one of the most pressing issues in current battery research. Lithium based batteries are prone to forming short-circuit causing dendrites, while magnesium based batteries are not. Recently it was proposed that the tendency towards dendrite growth is related to the height of the self-diffusion barrier with high barriers leading to rough surface growth which that subsequently cause dendrite formation, which was supported by density functional theory calculations for Li, Na and Mg [J. Chem. Phys., 2014, 141, 174710]. We now extend this computational study to zinc and aluminum which are also used as battery anode materials, and we additionally consider diffusion barriers that are relevant for three-dimensional growth such as barriers for diffusion across steps. Our results indicate, in agreement with experimental observations, that Li dendrite growth is an inherent property of the metal, whereas Zn dendrite growth results from the loss of metallic properties in conventional Zn powder electrodes.
The structure, lithium ion conductivity and reaction suppression against lithium of the novel xLaAlO3–(1− x)La0.57Li0.30TiO3 oxides (0≤ x ≤1) with a perovskite related structure (ABO3) are studied by using X-ray diffraction, ac impedance and digital multimeter. The results show that owing to the geometric environment, consisting of La3+, Li+ and vacancy at A-sites, the conductivities from x =0 to 20mol% are maintained in the range of 10−4 Scm−1, and decrease to 8.92×10−9 Scm−1 with 30–40mol% LaAlO3 addition. When the value of x is larger than 50mol%, the corresponding oxides no longer have the characteristic of ionic conduction. A stable solid electrolyte is also observed to alleviate the reaction significantly when the incorporated LaAlO3 content is 40mol%.
A novel LiFePO4/C composite with 3D carbon network was prepared using Cetyltrimethyl Ammonium Bromid (CTAB) and starch as carbon sources via a facile method. The 3D carbon network structure was composed of a full and uniform carbon coating and a continuous carbon film framework. Good conductive paths enhancing electrons transfer efficiency and porous structure facilitating diffusion of lithium ions have been constructed by the 3D conductive network structure, which contributes the high ionic and electrical conductivities. As a result, the LiFePO4/C composite possesses an excellent electrochemical performance especially the high-rate cyclic performance. It delivers a capacity of 95mAhg−1 at current density of 3.4Ag−1 (20C). After 1200 cycles, the discharge capacity of 74mAhg−1 can still be obtained, almost reaching a retention of 80%, which is higher than the best cyclic performance in previous investigations.
We successfully prepared a highly porous graphene on carbon cloth (PG/CC) via an electrophoretic deposition process. With this process, in order to obtain high porous graphene on carbon cloth, fine-size graphene should be used. When large-size graphene was used, carbon cloth was only covered by graphene (G/CC) without porous surface. PG/CC was used as electrodes for Flexible All-Solid-State Supercapacitors (FASSSs). The porous structure of PG/CC electrode significantly increased the surface area of graphene and thus the specific capacitance (79.19Fg−1 for PG/CC and 32.35Fg−1 for G/CC). The macroscopic porous morphology of carbon cloth as the electrode matrix enhanced the integration between electrode and electrolyte, which is favorable for the ion diffusion and electron transport. The excellent mechanical stability and flexibility of PG/CC ensures the device with good flexibility. The resultant PG/CC based FASSSs showed high specific capacitance, good cycling stability, and enhanced energy density and power density.
The longitudinal course of primary cognitive dysfunction seen in schizophrenia has yet to be fully clarified. Whereas some studies in chronic patients have revealed a progressive decline in cognitive abilities, those studies with first-episode patients have indicated that initial cognitive deficits might remain stable over time. The aim of this study was to examine the longitudinal course of cognitive functioning in patients with a first episode of schizophrenia. 112 patients with a first episode of schizophrenia-spectrum disorders and 22 healthy controls completed clinical and cognitive evaluations at baseline and again after 1 year. An extensive neuropsychological battery that comprised seven cognitive domains was used. Patients and controls improved their cognitive performance in virtually all the cognitive domains after one year. However, patients continued to show marked cognitive deficits after one year, unlike healthy volunteers. The longitudinal cognitive changes were similar in patients and controls in all domains except Verbal Memory (F = 11.67; df = 1; P = 0.001). The increase in cognitive scores found during early phases of the illness seems to be associated to practice-related changes and would not reflect a real cognitive enhancement but rather stability of deficit. Patients' deficits remained stable over time in all cognitive domains except Verbal Memory, in which less performance improvement was found. Further investigations are warranted to discern the variability in patterns of specific cognitive deficits over time.
Continuous force measurement can provide valuable insight to the efficacy of limb loading regimes during fracture rehabilitation. Currently there is no load monitoring device that is capable of more than 1 h of continuous recording. To enable continuous underfoot load monitoring a piezoresistive pressure sensor was encapsulated in a non-compressible silicone gel. This basic approach to signal transduction was implemented in three continuous underfoot load sensor designs. Design I constrained the gel in a rigid urethane housing. Design II constrained the gel in a silicone elastomer bladder. Design III utilized a hybrid approach by constraining the gel with a rigid upperplate inside of an elastomeric bladder. All three designs were subjected to bench and human testing. Design I outperformed the other two designs showing high linearity (correlation coefficient of 1), low static drift (<1%) and low dynamic drift (<3%) and captured the largest percentage of weight during human testing (35%). The sensor was designed, tested and shown to be durable and accurate for a 2 week window of time. This sensor has the low cost and high performance required for large scale clinical tests to correlate limb loading and fracture healing rates.
The effect of mechanical CPR is diversely described in the literature. Different mechanical CPR devices are available. The corpuls cpr is a new generation of piston-driven devices and was launched in 2015. The COMPRESS-trial analyzes quality of chest compression and CPR-related injuries in cases of mechanical CPR by the corpuls cpr and manual CPR.
LaCrO3 was prepared by glycine combustion method and investigated as negative electrode for Ni/MH batteries. The structures of the as-calcined powder and the 20th charge–discharge cycle sample were characterized by XRD. The electrochemical experimental results demonstrated that the LaCrO3 electrode showed excellent electrochemical reversibility and considerably high charge–discharge capacity at various temperatures. Except for the charge–discharge cycle at 298K, the discharge capacities of LaCrO3 electrode keep steady at 107.1mAhg−1and 285mAhg−1 at 313K and 333K after 5 cycles, respectively.
Polymer alloy technique is very powerful tool to tune the ionic conductivity and mechanical strength of polymer electrolyte. A semi-interpenetrating polymer network (semi-IPN) polymer alloy electrolyte, composed of non-cross-linkable siloxane-based polymer and cross-linked 3D network polymer, was prepared. Such polymer alloy electrolyte has quite high ionic conductivity (more than 10−4 Scm−1 at 25 °C and 10−5 Scm−1 at −10 °C) and mechanical strength as a separator film with a wide electrochemical stability window. A lithium metal/semi-IPN polymer alloy solid state electrolyte/LiCoO2 cell demonstrated promising cycle performance with room temperature operation of the energy density of 300Wh/L and better rate performance than conventional PEO based lithium polymer battery ever reported.
Solid-state lithium batteries (SSLBs) are promising next-generation energy storage devices due to their potential for high energy density and improved safety. The properties and physical parameters of the solid-state electrolyte (SSE), as a critical component of the battery, have a significant effect on the electrochemical performance and energy density. In recent years, thick SSEs have been widely used in SSLBs but present several drawbacks in terms of increased internal resistance, additional inactive material content, low practical energy densities, and higher battery manufacturing costs. Reducing the thickness of SSEs and developing high-performance thin SSE-based SSLBs are essential for the commercialization of SSLBs. In this review, we comprehensively summarize the fabrication methods of thin SSEs, their rational design, and their manufacturing processes and applications in different SSLB systems. Moreover, advanced characterization techniques for understanding the Li+ transport kinetics and structural evolution of SSEs at the interface are introduced. Additionally, the gravimetric/volumetric energy densities for various SSLB pouch cells with SSEs less than 100 μm thick are evaluated. Lastly, other cell design parameters are tuned to achieve gravimetric/volumetric energy densities over 300 W h kg−1/500 W h L−1, and the future directions of thin SSEs in SSLBs are speculated upon.
The present and future energy demands of burgeoning global population require an energy currency that can be obtained from clean and renewable resources. In this context, hydrogen as the future energy currency is widely considered as the solution to the energy crisis. Efficient electrocatalysis of hydrogen evolution reaction by inexpensive, highly active, abundant, environmental friendly and stable electrocatalyst is vital for the low-cost production of hydrogen. Carbon as the hydrogen evolution reaction catalyst support is explored since the initial period of the United States space program. The importance of carbon as the support material is understood by the fact that hydrogen evolution reaction electrocatalysis demands not only efficient electron transfer at its surface but also effective electron transport within the electrocatalyst. The hydrogen evolution reaction electrocatalysts presented in this review specifically have two components: 1) hydrogen evolution reaction active component and 2) carbon or carbon-based support for the active component. However, when carbon supports are coupled with the hydrogen evolution reaction active materials, the activity of these materials is enhanced significantly. The contribution of carbon support in the enhancement of the catalytic activity is discussed and highlighted by comparing the electrochemical parameters of supported and unsupported electrocatalysts where available.