Jiang Weikang, Zhu Kaiyue, Xie Weili, Ma Manxia, Li Weijian, Yang Weishen
Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China.
State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
Small. 2025 Jun;21(25):e2502723. doi: 10.1002/smll.202502723. Epub 2025 May 2.
Vanadium-based cathodes have attracted extensive attention in aqueous zinc-ion batteries (AZIBs) because of their high theoretical capacity. However, the development of high-performance vanadium-based cathodes and the establishment of effective design principles remain major challenges, hindering the progress of AZIBs technology. In this study, the critical role of structural building blocks ([VO] tetrahedra, [VO] square pyramids, and [VO] octahedra) is unveiled in vanadium-based oxides, demonstrating their distinct contributions to both capacity and stability. Among these, [VO] octahedra stand out for their superior capacity and stability, making vanadium oxides with [VO] octahedra promising candidates for AZIBs cathodes. Furthermore, it is shown that the presence of oxygen vacancies undermines the stability of [VO] building blocks by increasing the exposure of the vanadium sites. Based on these findings, amorphous vanadium oxide (ZVO-O-free), composed of oxygen vacancy-free [VO] octahedra arranged in short-range-ordered chains, is synthesized, maximizing the utilization of highly active vanadium sites. The ZVO-O-free cathode achieves a specific capacity of up to 483 mAh g at 0.3 A g, with a capacity retention of 94% after 150 cycles. These findings provide valuable insights for the rational design of vanadium-based oxides at the atomic and framework levels, paving the way for the practical development of AZIBs.
钒基阴极由于其高理论容量，在水系锌离子电池（AZIBs）中引起了广泛关注。然而，高性能钒基阴极的开发以及有效设计原则的建立仍然是主要挑战，阻碍了AZIBs技术的进步。在本研究中，揭示了结构单元（[VO]四面体、[VO]正方棱锥和[VO]八面体）在钒基氧化物中的关键作用，证明了它们对容量和稳定性的不同贡献。其中，[VO]八面体因其卓越的容量和稳定性脱颖而出，使含有[VO]八面体的钒氧化物成为AZIBs阴极的有前景的候选材料。此外，研究表明氧空位的存在通过增加钒位点的暴露破坏了[VO]结构单元的稳定性。基于这些发现，合成了由短程有序链排列的无氧空位的[VO]八面体组成的非晶态钒氧化物（ZVO-O-free），最大限度地利用了高活性钒位点。ZVO-O-free阴极在0.3 A g下实现了高达483 mAh g的比容量，在150次循环后容量保持率为94%。这些发现为在原子和框架水平上合理设计钒基氧化物提供了有价值的见解，为AZIBs的实际开发铺平了道路。
