Yao Xincheng, Khanam Zeba, Li Chenglin, Koroma Malcolm, Ouyang Ting, Hu Yu-Wen, Shen Ke, Balogun M-Sadeeq
College of Materials Science and Engineering, Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy, Hunan University, Changsha, 410082, P. R. China.
National Engineering Research Center for High Efficiency Grinding, State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China.
Small. 2024 Jul;20(30):e2312036. doi: 10.1002/smll.202312036. Epub 2024 Feb 23.
Vanadium-based materials, due to their diverse valence states and open-framework lattice, are promising cathodes for aqueous zinc ion batteries (AZIBs), but encounters the major challenges of in situ electrochemical activation process, potent polarity of the aqueous electrolyte and periodic expansion/contraction for efficient Zn storage. Herein, architecting vanadium nitride (VN) nanosheets over titanium-based hollow nanoarrays skeletal host (denoted VNTONC) can simultaneously modulate address those challenges by creating multiple interfaces and maintaining the (1 1 1) phase of VN, which optimizes the Zn storage and the stability of VN. Benefiting from the modulated crystalline thermodynamics during the electrochemical activation of VN, two outcomes are achieved; I) the cathode transforms into a nanocrystalline structure with increased active sites and higher conductivity and; II) a significant portion of the (1 1 1) crystal facets is retained in the process leading to the additional Zn storage capacity. As a result, the as-prepared VNTONC electrode demonstrates remarkable discharge capacities of 802.5 and 331.8 mAh g @ 0.5 and 6.0 A g, respectively, due to the enhanced kinetics as validated by theoretical calculations. The assembled VNTONC||Zn flexible ZIB demonstrates excellent Zn storage properties up to 405.6 mAh g, and remarkable robustness against extreme operating conditions.
钒基材料因其多样的价态和开放框架晶格，有望成为水系锌离子电池（AZIBs）的正极材料，但面临原位电化学活化过程、水系电解质强极性以及有效储存锌时的周期性膨胀/收缩等主要挑战。在此，在钛基中空纳米阵列骨架基体上构建氮化钒（VN）纳米片（记为VNTONC），可以通过创建多个界面并维持VN的（1 1 1）相来同时应对这些挑战，从而优化锌储存和VN的稳定性。受益于VN电化学活化过程中调制的晶体热力学，实现了两个结果：I）正极转变为具有更多活性位点和更高导电性的纳米晶体结构；II）在该过程中保留了相当一部分（1 1 1）晶面，从而带来额外的锌储存容量。结果，所制备的VNTONC电极在0.5和6.0 A g下分别表现出802.5和331.8 mAh g的显著放电容量，理论计算验证了其动力学增强。组装的VNTONC||Zn柔性水系锌离子电池表现出高达405.6 mAh g的优异锌储存性能，以及对极端工作条件的显著鲁棒性。
