PANI-Coated VOx Nanobelts with Core-Shell Architecture for Flexible All-Solid-State Supercapacitor.

As a typical pseudocapacitor material, VOx possesses mixed valence states, making it an ideal electrode material for symmetric screen-printed supercapacitors. However, its high internal resistance and low energy density are the main hurdles to its widespread application. In this study, a two-dimensional PANI@VOx nanobelt with a core-shell architecture was constructed via a two-step route. This strategy involves the preparation of VOx using a solvothermal method, and a subsequent in situ polymerization process of the PANI. By virtue of the synergistic effect between the VOx core and the PANI shell, the optimal VOx@PANI has an enhanced conductivity of 0.7 ± 0.04 S/Ω, which can deliver a high specific capacitance of 347.5 F/g at 0.5 A/g, a decent cycling life of ~72.0%, and an outstanding Coulomb efficiency of ~100% after 5000 cycles at 5 A/g. Moreover, a flexible all-solid-state symmetric supercapacitor (VOx@PANI SSC) with an in-planar interdigitated structure was screen-printed and assembled on a nickel current collector; it yielded a remarkable areal energy density of 115.17 µWh/cm2 at an areal power density of 0.39 mW/cm2, and possessed outstanding flexibility and mechanical performance. Notably, a "Xiaomi" hygrothermograph (3.0 V) was powered easily by tandem SSCs with an operating voltage of 3.1 V. Therefore, this advanced pseudocapacitor material with core-shell architecture opens novel ideas for flexible symmetric supercapacitors in powering portable/wearable products.

Flexible High-Performance and Screen-Printed Symmetric Supercapacitor Using Hierarchical Rodlike V3O7 Inks.

The emergence of the Internet of things stimulates the pursuit of flexible and miniaturized supercapacitors. As an advanced technology, screen printing displays vigor and tremendous potential in fabricating supercapacitors, but the adoption of high-performance ink is a great challenge. Here, hierarchical V3O7 with rodlike texture was prepared via a facile template-solvothermal route; and the morphology, component, and valence bond information are characterized meticulously. Then, the screen-printed inks composed of V3O7, acetylene black, and PVDF are formulated, and the rheological behaviors are studied detailedly. Benefitting from the orderly aligned ink, the optimal screen-printed electrode can exhibit an excellent specific capacitance of 274.5 F/g at 0.3 A/g and capacitance retention of 81.9% after 5000 cycles. In addition, a flexible V3O7 symmetrical supercapacitor (SSC) is screen-printed and assembled on the Ag current collector, exhibiting a decent areal specific capacitance of 322.5 mF/cm2 at 0.5 mA/cm2, outstanding cycling stability of 90.8% even after 5000 cycles, satisfactory maximum energy density of 129.45 µWh/cm2 at a power density of 0.42 mW/cm2, and remarkable flexibility and durability. Furthermore, a single SSC enables the showing of an actual voltage of 1.70 V after charging, and no obvious self-discharge phenomenon is found, revealing the great applied value in supply power. Therefore, this work provides a facile and low-cost reference of screen-printed ink for large-scale fabrication of flexible supercapacitors.

Unusual Size Effect in Ion and Charge Transport in Micron-Sized Particulate Aluminum Anodes of Lithium-Ion Batteries.

Aluminum is a promising anode material for lithium-ion batteries owing to its high theoretical capacity, excellent conductivity, and natural abundance. An anomalous size effect was observed for micron-sized aluminum powder electrodes in this work. Experimental and theoretical investigations reveal that the insulating oxide surface layer is the underlying cause, which leads to poor electrical conductivity and limited capacity utilization when the particle is too small. Additionally, poor electrolyte wettability also accounts for the hindered reaction kinetics due to the weak polarity feature of the oxide layer. Surface grafting of polar amino groups was demonstrated to be an effective strategy to improve electrolyte wettability. The present work revealed the critical limitations and underlying mechanisms for the aluminum anode, which is crucial for its practical application. Our results are also valuable for other metallic anodes with similar issues.

The Continued Use of Social Commerce Platforms and Psychological Anxiety-The Roles of Influencers, Informational Incentives and FoMO.

Why does the continued use of social commerce platforms fail to promote consumer wellbeing? This study explores the roles of influencers, informational incentives and fear of missing out (FoMO) in the relationships between social commerce platform use and consumer mental health. Data were obtained through questionnaires, as well as constructing a research model. Statistical analysis and path analysis of the structural equation model were performed by the software IBM SPSS and AMOS, and the following results were obtained. (1) Influencer expertise and interactivity, informational incentives and FoMO have a significant impact on consumers' continued use of social commerce platforms. (2) Materialism has no significant effect on consumer social commerce platform use. (3) FoMO mediates the relationships between informational incentives and continued use of social commerce platforms. (4) Consumers' continuous use of social commerce platforms has a strong relationship with mental health. (5) Continued use of social commerce platforms can lead to intense social engagement, as well as more severe outcomes such as psychological anxiety and compulsive buying. The findings of the paper have important implications for the development of social business theory and management practice.

Neutrophil/lymphocyte ratio is helpful for predicting weaning failure: a prospective, observational cohort study.

BACKGROUND: To assess the usefulness of the neutrophil/lymphocyte ratio (NLR), a marker of inflammation and/or stress, for predicting weaning failure in patients receiving invasive mechanical ventilation (IMV), compared to levels of leukocytes and C-reactive protein (CRP). METHODS: This observational prospective cohort study was conducted from July 2013 to December 2016 in an intensive care unit in China, enrolling 269 consecutive patients receiving IMV. Patients underwent a spontaneous breathing trial (SBT) if they were ready to wean, and underwent extubation if they passed the SBT. The evaluated markers were measured immediately prior to SBT, and compared between weaning-failure and weaning-success patients. Receiver-operating characteristic (ROC) curve and logistic regression analyses were used to evaluate the ability of these markers to predict weaning failure. RESULTS: In all, 94 (34.9%) patients failed the weaning process (66 failed SBT and 28 presented with post-extubation respiratory distress). NLR was a better predictor of failure (area under the ROC curve, 0.69; 95% CI, 0.62-0.76) than leukocyte levels (0.60, 0.53-0.67) and CRP values (0.58, 0.51-0.65). NLR >11, leukocyte counts >10.5×109/L, and CRP >58 mg/L prior to weaning had the best combination of sensitivity (73%, 64%, and 63%, respectively), specificity (59%, 55%, and 63%), positive predictive value (49%, 43%, and 48%), negative predictive value (81%, 74%, and 76%), and diagnostic accuracy (64%, 58%, and 63%) for predicting weaning failure. However, only NLR >11 (odds ratio, 5.91; 95% CI, 3.08-11.33; P<0.001) was an independent predictor of weaning failure in the adjusted logistic regression model. CONCLUSIONS: NLR may be a useful marker for predicting weaning failure, and weaning at NLR >11 might be considered with caution. Further study with a larger sample size and with weaning outcome as a variable of concern is warranted. Trial registration: ClinicalTrials.gov identifier: NCT02981589.