Tuning the Kinetics of Zinc-Ion Insertion/Extraction in V2O5 by In Situ Polyaniline Intercalation Enables Improved Aqueous Zinc-Ion Storage Performance
Tuning the Kinetics of Zinc-Ion Insertion/Extraction in V2O5 by In Situ Polyaniline Intercalation Enables Improved Aqueous Zinc-Ion Storage Performance
复制标题
通过原位聚苯胺插层调节 V2O5 中锌离子插入/脱出的动力学，可提高水相锌离子存储性能
DOI：
10.1002/adma.202001113
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发表时间：
2020-05-20
影响因子：
29.4
通讯作者：
Li, Cheng Chao
中科院分区：
文献类型：
--
作者：
Liu, Sucheng;Zhu, He;Li, Cheng Chao
可充电锌离子电池（ZIB）正在成为锂离子电池的一种有前途的替代品。然而，开发的阴极遭受缓慢的Zn 2+扩散动力学，导致差的倍率性能和不足的循环寿命。在此，在原位聚苯胺（PANI）插层策略开发，以促进Zn 2+的（脱）插在V2 O 5的动力学。以这种方式，可以在V-O层之间交替地构造显著增大的层间距离（13.90埃），从而为容易的Zn 2+扩散提供加速通道。重要的是，Zn 2+和主体O2-之间的静电相互作用，这是阻碍Zn 2+扩散动力学的另一个关键因素，可以被PANI独特的π共轭结构有效地阻断。结果表明，PANI插层的V2 O 5在Zn 2+的重复插入和提取过程中表现出稳定和高度可逆的电化学反应，原位同步辐射X射线衍射和拉曼光谱研究证实了这一点。进一步的第一性原理计算清楚地揭示了一个显着降低的结合能之间的Zn 2+和主机O2-，这解释了有利的动力学聚苯胺插层V2 O 5。结果表明，PANI插层V2 O 5电极的电化学性能得到了显著提高，在20 A g（-1）的电流密度下，其高倍率放电容量为197.1 mAh g（-1），2000次循环的容量保持率为97.6%。
Rechargeable zinc-ion batteries (ZIBs) are emerging as a promising alternative for Li-ion batteries. However, the developed cathodes suffer from sluggish Zn2+ diffusion kinetics, leading to poor rate capability and inadequate cycle life. Herein, an in situ polyaniline (PANI) intercalation strategy is developed to facilitate the Zn2+ (de)intercalation kinetics in V2O5. In this way, a remarkably enlarged interlayer distance (13.90 angstrom) can be constructed alternatively between the V-O layers, offering expediting channels for facile Zn2+ diffusion. Importantly, the electrostatic interactions between the Zn2+ and the host O2-, which is another key factor in hindering the Zn2+ diffusion kinetics, can be effectively blocked by the unique pi-conjugated structure of PANI. As a result, the PANI-intercalated V2O5 exhibits a stable and highly reversible electrochemical reaction during repetitive Zn2+ insertion and extraction, as demonstrated by in situ synchrotron X-ray diffraction and Raman studies. Further first-principles calculations clearly reveal a remarkably lowered binding energy between Zn2+ and host O2-, which explains the favorable kinetics in PANI-intercalated V2O5. Benefitting from the above, the overall electrochemical performance of PANI-intercalated V2O5 electrode is remarkable improved, exhibiting excellent high rate capability of 197.1 mAh g(-1) at current density of 20 A g(-1) with capacity retention of 97.6% over 2000 cycles.