High-performance 3D biphasic NH4V3O8/Zn3(OH)2V2O7·2H2O synthesized by rapid chemical precipitation as cathodes for Zn-ion batteries

Abstract

Vanadate with layered structures and large open frameworks has been extensively explored as cathodes materials for aqueous Zn-ion batteries (ZIBs), and superior Zn-ion storage performance have been achieved. The biphasic vanadate materials are investigated to be conducive for further performance improvement. However, the lack of rapid and scalable synthesis strategies poses stiff challenges for the wider industrial economy of vanadate. Herein, the 3D biphasic NH4V3O8/Zn3(OH)2V2O7·2H2O (NVO/ZVO) were obtained via rapid microwave irradiation assisted chemical precipitation. The prepared electrode by NVO/ZVO with multiple nanoflower-structures presents a high specific capacity (332 mAh g−1 at 0.1 A g−1), together with exceedingly good energy density (281 Wh kg−1) and power density (94 W kg−1). Moreover, it can maintain a specific capacity of 92 % (132 mAh g−1) after 1000 cycles at a high current density of 10 A g−1. The high electrochemical performance of the cathode can be ascribed to the energy storage mechanism of dual-ion intercalation. This work provides key insights into the rapid synthesis of high-performance biphasic vanadate cathode materials for advanced ZIBs.

Keywords

• Aqueous Zn-ion batteries
• Biphasic vanadate
• Rapid chemical precipitation synthesis
• 3D skeleton structure