Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education, School of Materials Science and Engineering, Beihang University, 100191, Beijing, China.
School of Material and Chemical Engineering, Zhengzhou University of Light Industry, 450002, Zhengzhou, China.
Adv Mater. 2018 Jun;30(26):e1800762. doi: 10.1002/adma.201800762. Epub 2018 May 15.
Although rechargeable aqueous zinc-ion batteries have attracted extensive interest due to their environmental friendliness and low cost, they still lack suitable cathodes with high rate capabilities, which are hampered by the intense charge repulsion of bivalent Zn . Here, a novel intercalation pseudocapacitance behavior and ultrafast kinetics of Zn into the unique tunnels of VO (B) nanofibers in aqueous electrolyte are demonstrated via in situ X-ray diffraction and various electrochemical measurements. Because VO (B) nanofibers possess unique tunnel transport pathways with big sizes (0.82 and 0.5 nm along the b- and c-axes) and little structural change on Zn intercalation, the limitation from solid-state diffusion in the vanadium dioxide electrode is eliminated. Thus, VO (B) nanofibers exhibit a high reversible capacity of 357 mAh g , excellent rate capability (171 mAh g at 300 C), and high energy and power densities as applied for zinc-ion storage.
尽管可充电水系锌离子电池因其环保和低成本而受到广泛关注，但它们仍然缺乏具有高倍率性能的合适阴极，这受到二价 Zn 强烈的电荷排斥的阻碍。在这里，通过原位 X 射线衍射和各种电化学测量，证明了在水溶液电解质中，独特的 VO(B)纳米纤维中的插层赝电容行为和 Zn 的超快动力学。由于 VO(B)纳米纤维具有独特的隧道传输途径，其大小较大（沿 b-和 c-轴分别为 0.82 和 0.5nm），并且在 Zn 嵌入过程中结构变化较小，因此消除了二氧化钒电极中固态扩散的限制。因此，VO(B)纳米纤维表现出高可逆容量 357mAh g-1，优异的倍率性能（在 300C 时为 171mAh g-1），以及作为锌离子存储应用的高能量和功率密度。
