Wu Jian, Liang Hanhao, Li Jiaming, Yang Zhanhong, Cai Jingbo
Hunan Province Key Laboratory of Chemical Power Source, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China; Innovation Base of Energy and Chemical Materials for Graduate Students Training, Central South University, Changsha 410083, China.
Hunan Province Key Laboratory of Chemical Power Source, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China; Innovation Base of Energy and Chemical Materials for Graduate Students Training, Central South University, Changsha 410083, China.
J Colloid Interface Sci. 2024 Jan 15;654(Pt A):46-55. doi: 10.1016/j.jcis.2023.09.177. Epub 2023 Oct 10.
Rechargeable aqueous zinc ion batteries (RAZIBs) are of interest for energy storage in smart grids. However, slow Zn diffusion kinetics, insufficient active sites, and poor intrinsic conductivity are always challenging to exploit the huge potential of the batteries. Here, we prepare VO-VN nano-heterojunction composites with sea urchin-like morphology as the cathode for AZIBs. The electrode achieves high capacities (e.g., 0.1 A g, 532.6 mAh g), good rate and cycle performance (263.4 mAh g at 5 A g current density with 90.8% capacity retention). Detailed structural analyses suggest that the VO-VN composite is composed of different crystal planes of VO and VN, which form an efficient heterogeneous interfacial network in the bulk electrode, accounting for its good electrochemical properties. Theoretical calculations reveal that compared with VO, VN and physically mixed VO/VN, the VO-VN heterostructure exhibits good cation adsorption and electrode conductivity, thereby accelerating the charge carrier mobility and electrochemical activity of the electrode. Moreover, ex-situ characterization techniques are utilized to investigate the zinc storage mechanism in detail, providing new ideas for the development of AZIBs cathode materials through the construction of heterojunction structures.
可充电水系锌离子电池（RAZIBs）在智能电网储能方面具有吸引力。然而，缓慢的锌扩散动力学、活性位点不足以及本征电导率差一直是挖掘该电池巨大潜力的挑战。在此，我们制备了具有海胆状形貌的VO-VN纳米异质结复合材料作为水系锌离子电池的正极。该电极实现了高容量（例如，0.1 A g时为532.6 mAh g）、良好的倍率性能和循环性能（在5 A g电流密度下为263.4 mAh g，容量保持率为90.8%）。详细的结构分析表明，VO-VN复合材料由VO和VN的不同晶面组成，它们在块状电极中形成了高效的异质界面网络，这解释了其良好的电化学性能。理论计算表明，与VO、VN和物理混合的VO/VN相比，VO-VN异质结构表现出良好的阳离子吸附和电极电导率，从而加速了电极的电荷载流子迁移率和电化学活性。此外，利用非原位表征技术详细研究了锌存储机制，为通过构建异质结结构开发水系锌离子电池正极材料提供了新思路。
