4 research outputs found

    Silver vanadium bronze, beta-Ag0.33V2O5: crystal-water-free high-capacity cathode material for rechargeable Ca-ion batteries

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    Calcium-ion batteries (CIBs) are getting increasing attention as post-lithium-ion batteries owing to their theoretical and potential advantages in terms of energy density and cost-effectiveness. However, most of the reported cathode materials suffer from low capacity or cyclability in dried nonaqueous electrolytes. So far, all of the materials with high capacity (>100 mA h g−1) contain crystal water, which was considered to be crucial to the structural stability, enabling facile Ca diffusion. Here, we report β-Ag0.33V2O5as a high-capacity cathode material for CIBs without crystal water. After the initial activation process, the material exhibited a capacity of 179 mA h g−1at approximately 2.8 V (vs.Ca2+/Ca) in the ninth cycle and showed a modest cycling performance. The capacity is the highest among the Ca cathode materials without crystal water reported to date. We revealed that the activation process was caused by a replacement reaction between the silver and calcium ions. This material demonstrates that crystal water is not an essential component of CIB electrode materials for a high capacity, stimulating the ongoing research for developing higher-performance materials. © The Royal Society of Chemistry 2021.FALS

    Reversible Calcium-Ion Insertion in NASICON-Type NaV2(PO4)3

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    The recent discovery of reversible plating and alloying of calcium has invoked considerable interest in calcium-based rechargeable batteries toward overcoming the limitations of conventional Li-ion batteries. However, only a few cathode materials have been tested thus far, and these exhibit low energy-storage capability and poor cyclability. Herein, the highly reversible Ca-intercalation capability of NASICON-type NaV2(PO4)3 makes it a potential cathode material for nonaqueous Ca-ion batteries, with high capacity and voltage and good cyclability (90 mA h g-1 and ∼3.4 V at 11.7 mA g-1 and 75 °C; 70 mA h g-1 and ∼3.2 V at 5.85 mA g-1 and 25 °C). Although this work shows only the capability of the cathode, not a full-cell performance, it does demonstrate experimentally that a poly-oxyanionic material can provide an outstanding host structure for Ca diffusion at room temperature with high energy-storage capability. © 2020 American Chemical Society.1

    Association between Smoking Behavior Patterns and Glycated Hemoglobin Levels in a General Population

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    This study investigated the association of smoking behaviors, including dual smoking (smoking both cigarettes and e-cigarettes), cigarettes smoking, and previous smoking, with glycated hemoglobin (HbA1c) levels. National Health and Nutrition Examination Survey (KNHANES) data from 2014–2016 was used. Associations between smoking behavior patterns and HbA1c levels were analyzed via multiple regression. Among 8809 participants, individuals who were dual smokers and cigarettes smokers had significantly higher HbA1c levels than non-smokers (dual: β = 0.1116, p = 0.0012, single: β = 0.0752, p = 0.0022). This relationship strengthened in subgroups of men (dual: β = 0.1290, p = 0.0013, single: β = 0.1020, p = 0.0014, ex: β = 0.0654, p = 0.0308), physically inactive subjects (dual: β = 0.1527, p = 0.0053, single: β = 0.0876, p = 0.0197), and overweight (dual: β = 0.1425, p = 0.0133) and obese individuals (dual: β = 0.1694, p = 0.0061, single: β = 0.1035, p = 0.0217). This study suggests that smoking behaviors are likely to increase the risk of HbA1c level in a general population. The health effects of dual smoking remain uncertain and should be addressed in the future
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