Luo Yi, Wei Licheng, Geng Hongbo, Zhang Yufei, Yang Yang, Li Cheng Chao
School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China.
ACS Appl Mater Interfaces. 2020 Mar 11;12(10):11753-11760. doi: 10.1021/acsami.0c00057. Epub 2020 Feb 28.
Vanadium oxides have been considered as promising cathode candidates for zinc-ion batteries (ZIBs) because of their high theoretical specific capacity. However, the poor rate performance and the unsatisfactory cycle life resulting from the sluggish electrode kinetics seriously impede their practical implementation. Herein, we report the rational design of amorphous Fe-V-O bimetallic oxides with tunable compositions as cathodes for aqueous ZIBs. The bimetallic Fe-V-O oxides show improved composition-dependent Zn storage performance and superior structural integrity during cycling. The enhanced electrode kinetics is attributed to the superior electronic conductivity of Fe-V-O oxides than pristine VO owing to the introduction of the Fe element and an amorphous crystalline structure, which can provide reduced diffusion paths and more free volume for Zn insertion. As a result, the as-prepared Fe-V-O exhibits outstanding rate capability and impressive cycling stability. Particularly, a stable reversible capacity of 70 mA h g can be still maintained after 2500 cycles at 5 A g, corresponding to the high capacity retention of 95%.
由于具有较高的理论比容量，钒氧化物被认为是锌离子电池（ZIBs）很有前景的阴极候选材料。然而，电极动力学迟缓导致的倍率性能差和循环寿命不理想严重阻碍了它们的实际应用。在此，我们报道了具有可调组成的非晶态铁 - 钒 - 氧双金属氧化物作为水系锌离子电池阴极的合理设计。双金属铁 - 钒 - 氧氧化物在循环过程中表现出改善的与组成相关的锌存储性能和优异的结构完整性。电极动力学的增强归因于铁 - 钒 - 氧氧化物比原始VO具有更高的电子导电性，这是由于引入了铁元素以及非晶态晶体结构，该结构可以为锌插入提供缩短的扩散路径和更多的自由体积。结果，所制备的铁 - 钒 - 氧表现出出色的倍率性能和令人印象深刻的循环稳定性。特别是，在5 A g下经过2500次循环后，仍可保持70 mA h g的稳定可逆容量，对应95％的高容量保持率。
