Aqueous rechargeable Zn ion batteries (ARZIBs) are investigated as a capable alternative battery technology for a large-scale energy storage system. Exploring and understanding the Zn ions storage mechanism is a significant method to adjust the Zn ion storage behavior of electrode materials. Herein, we demonstrate a phase transition of the (NH₄)₂V₄O₉ cathode material at the voltage of above 1.3 V. After the initial Zn²⁺ insertion/extraction process, bilayer V₂O₅·nH₂O is observed and the interlayer spacing is enlarged, boosting the electrochemical performance of the electrode. The cathode materials show an enhanced capacity of 508 mAh g⁻¹ at 100 mA g⁻¹ and stable cycling performance (259 mAh g⁻¹ after 1000 cycles at 10 A g⁻¹, with 98.2% capacity retention). Moreover, the (NH₄)₂V₄O₉ nanosheets exhibited a remarkable specific energy density of 373.2 Wh kg⁻¹ at a power density of 74.6 W kg⁻¹, suggesting its potential application for the high-performance ARZIBs.

水性可再充电锌离子电池（ARZIBs）被研究为大型能量存储系统的有效替代电池技术。探索和理解Zn离子的存储机理是调节电极材料Zn离子存储行为的重要方法。本文中，我们展示了（NH ₄）₂ V ₄ O ₉正极材料在高于1.3 V的电压下的相变。在最初的Zn ²⁺插入/萃取过程之后，双层V ₂ O ₅ · n H ₂观察到O，并且层间间隔增大，从而增强了电极的电化学性能。阴极材料显示的508毫安克的增强的容量^-1 在100mA克^-1和稳定的循环性能（259毫安克^-1 1000次循环在10 A G之后^-1，以98.2％的容量保持率）。此外，（NH ₄）_2个V ₄ ø ₉纳米片表现出373.2瓦公斤的一个显着的比能量密度^-1 在74.6公斤w ^的功率密度^-1，表明其为高性能ARZIBs潜在的应用。