In-situ tuning the NH4+ extraction in (NH4)2V4O9 nanosheets towards high performance aqueous zinc ion batteries

• Published in: Journal of power sources Vol. 492; p. 229629
• Main Authors: Cui, Fuhan, Hu, Fang, Yu, Xin, Guan, Chao, Song, Guihong, Zhu, Kai
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30.04.2021
• Subjects: (NH4)2V4O9; Aqueous zinc-ion batteries; Electrochemical performance; Nanosheets; (NH4)2V4O9; Nanosheets; Electrochemical performance; Aqueous zinc-ion batteries
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2021.229629

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. •The (NH4)2V4O9 nanosheets was synthesized by a facile hydrothermal method.•(NH4)2V4O9 showed a high capacity of 508 mAh g−1 at 100 mA g−1.•The phase transfer from (NH4)2V4O9 to V2O5·nH2O was observed.•Electrochemical phase transition process enhanced the Zn ion storage behavior.•The high ratio of capacitive contribution promised capable rate ability.