Morphology-Dependent Electrochemical Performance of Zinc Hexacyanoferrate Cathode for Zinc-Ion Battery.
Morphology-Dependent Electrochemical Performance of Zinc Hexacyanoferrate Cathode for Zinc-Ion Battery.
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锌离子电池用六氰基铁酸锌正极的形貌相关电化学性能
DOI：
10.1038/srep18263
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发表时间：
2015-12-16
影响因子：
4.6
通讯作者：
Liu Z
中科院分区：
文献类型：
--
作者：
Zhang L;Chen L;Zhou X;Liu Z
六氰合铁酸锌（ZnHCF）是一种二晶型（立方或菱面体）普鲁士蓝类似物，可被一价和二价离子嵌入，是一种很有前途的可充水溶液金属离子电池正极材料。在室温下得到了立方八面体、截顶八面体和八面体三种多面体ZnHCF颗粒。在70 °C进一步脱水，ZnHCF晶体由立方相转变为菱方相，但脱水后的ZnHCF晶体仍保持立方相的多面体形状。然后研究了菱面体结构多面体ZnHCF（RZnHCF）的形貌和晶面对其电化学性能的影响。与截顶八面体或八面体形状的RZnHCF颗粒相比，立方八面体形状的RZnHCF颗粒具有最好的倍率性能和循环稳定性。此外，在电化学循环过程中的立方八面体RZnHCF颗粒的结构已被监测与situX射线衍射证明可逆的锌离子嵌入机制。
Zinc hexacyanoferrate (ZnHCF) which is a dimorphic (cubic or rhombohedral) Prussian blue analogue and can be intercalated by both monovalent and divalent ions,is a promising cathode material for rechargeable aqueous metal-ion batteries.In this paper, a simple co-precipitation method is developed to tune the particle morphology of ZnHCF by adjusting the dropping speed at room temperature. Three polyhedral ZnHCF particles, with cubooctahedral, truncated octahedral or octahedral shapes, are obtained at room temperature. Structural transformation from cubic phase of as-prepared ZnHCF to rhombohedral phase is observed by further dehydration of the sample at 70 °C, whereas the dehydrated ZnHCF crystals still hold the identical polyhedral shape as that of the cubic phase particles. Then the influence of shape and facets on electrochemical performance is studied for polyhedral ZnHCF with rhombohedral structure (RZnHCF). RZnHCF sample with cubooctahedral shape possesses the best rate capability and cyclic stability comparing with RZnHCF particles having truncated octahedral or octahedral shapes. Furthermore, the structure of cuboctahedron RZnHCF particles during electrochemical cycling has been monitored withex situX-ray diffraction to demonstrate the reversible zinc-ion intercalation mechanism.