Additive‐Free Ultrastable Hydrated Vanadium Oxide Sol/Carbon Nanotube Ink for Durable and High‐Power Aqueous Zinc‐Ion Battery

Abstract Aqueous zinc‐ion batteries (ZIBs) based on near‐neutral electrolytes represent a promising large‐scale energy storage solution for a deeper and broader penetration of clean renewable energy. The preparation of electrode paste is vital for the normal performance and stability of ZIBs. Herein, the authors report an additive‐free V 2 O 5 ·1.6H 2 O ( h ‐V 2 O 5 )/carbon nanotube (CNT) hybrid ink to prepare large‐scale free‐standing h ‐V 2 O 5 /CNT film for high‐rate and durable ZIBs. The as‐prepared h ‐V 2 O 5 /CNT film exhibits a high specific capacity of 446.4 mA h g −1 (volumetric capacity of 839.2 mA h cm −3 ) at 0.2 A g −1 when used as cathode for ZIBs. It retains considerable capacities of 202.3 and 139.0 mA h g −1 even at high current densities of 20 and 50 A g− 1 , respectively, exhibiting ultrahigh rate capability. The assembled cell also displays outstanding long‐term cycling stability with a remarkable capacity of 309.7 mA h g −1 even after 3500 cycles at 10 A g −1 . More importantly, this h ‐V 2 O 5 sol can serve as a general “surfactant” to disperse a variety of nanomaterials in water. This work proposes a facile strategy to prepare additive‐free paste for conductive electrode, which holds great potential for a broad range of applications.