Cui Rukun, Gu Jianmin, Wang Ning, Wang Yiran, Huang Xiaoyan, Zhang Senlin, Lu Li, Wang Desong
State Key Laboratory of Metastable Materials Science and Technology (MMST), Hebei Key Laboratory of Applied Chemistry, Yanshan University, Qinhuangdao, 066004, P. R. China.
Department of Mechanical Engineering, National University of Singapore, Singapore, 117576, Singapore.
Small. 2024 Feb;20(7):e2307849. doi: 10.1002/smll.202307849. Epub 2023 Oct 8.
Although the layered vanadium oxide-based materials have been considered to be one of the candidates for aqueous Zn-ion batteries (AZIBs), it still faces inevitable challenges of unsatisfactory capacities and sluggish kinetics because of strong electrostatic interactions between Zn-ions and structure lattice. This work addresses the strategy of pre-inserting guest materials to vanadium oxide cathode using different intercalants. To achieve this goal, the small organic dye molecules, methyl orange (MO), and methylene blue (MB) are proposed as the intercalants for vanadium oxygen hydrate (VOH). It has been demonstrated that use of these intercalants can facilitate reaction kinetics between Zn and VOH, leading to an improvement of specific capacity (293 mAh g at 0.3 A g for MO-VOH and 311 mAh g for MB-VOH) compared to VOH, a large enhancement of excellent energy density (237.1 Wh kg for MO-VOH, 232.3 Wh kg for MB-VOH), and a prolong lifespan operation at 3 A g . The mechanism studies suggest that the weakened electrostatic interactions between the Zn-ions and V-O lattice after intercalating organic molecules contribute to boosting the electrochemical performance of AZIBs unveiled by charge density difference and binding energy.
尽管层状钒氧化物基材料被认为是水系锌离子电池（AZIBs）的候选材料之一，但由于锌离子与结构晶格之间存在强烈的静电相互作用，它仍然面临着容量不理想和动力学迟缓等不可避免的挑战。这项工作提出了使用不同插层剂将客体材料预插入钒氧化物阴极的策略。为实现这一目标，提出了小有机染料分子甲基橙（MO）和亚甲基蓝（MB）作为水合钒氧化物（VOH）的插层剂。结果表明，使用这些插层剂可以促进锌与VOH之间的反应动力学，与VOH相比，比容量有所提高（MO-VOH在0.3 A g时为293 mAh g，MB-VOH为311 mAh g），能量密度大幅提高（MO-VOH为237.1 Wh kg，MB-VOH为232.3 Wh kg），并在3 A g下延长使用寿命。机理研究表明，插入有机分子后锌离子与V-O晶格之间静电相互作用的减弱有助于提高AZIBs的电化学性能，这一点由电荷密度差和结合能揭示。
