Simultaneous Construction of Hydrophobic Environment and Optimized Ion Channels in V 2 O 5 for Zinc Ion Batteries

ABSTRACT Vanadium‐based oxides are commonly used as cathode materials for aqueous zinc ion batteries (AZIBs), offering the advantages of open crystalline structure and high theoretical capacity. However, vanadium‐based oxides are limited in further application development by poor structural stability and uncontrollable dissolution. Here, the hexamethylenediammonium (HMA 2+ ) preintercalated V 2 O 5 cathode (HVOH) is constructed to enhance the comprehensive performance of AZIBs. In terms of active material stability, the lamellar structure is stabilized with the existence of interlayer pillar HMA 2+ , and the cathodic hydrophobicity is enhanced by long alkyl chains to inhibit vanadium dissolution and water‐related side reactions. Besides, the interlayer spacing (13 Å) is widened, and new active sites are introduced due to the preintercalated HMA 2+ , realizing higher capacity performance. Specifically, the insertion of ions into the low‐voltage area is significantly increased. The electrostatic interaction between the V 2 O 5 layer and Zn 2+ is weakened thanks to the positive electrical properties of HMA 2+ . Thus, accelerated diffusion rates and electrochemical kinetics are obtained. As a result, the assembled Zn||Zn(CF 3 SO 3 ) 2 ||HVOH cell obtains a high specific capacity of 431.7 mAh g −1 at 0.2 A g −1 and achieves an improved cycling performance at 10 A g −1 (137.5 mAh g −1 after 3000 cycles). This strategy provides a perspective for the optimization of layered vanadium oxides by organic cationic preintercalation.