VOC Bonding of Heterointerface Boosting Kinetics of Free‐Standing Na₅V₁₂O₃₂ Cathode for Ultralong Lifespan Sodium‐Ion Batteries

Abstract The flexible free‐standing cathodes with high energy density have been challenging toward wearable sodium‐ion batteries (SIBs). Herein, Na 5 V 12 O 32 nanobelts (NVO‐NBs)‐based heterostructure is fabricated with boosting the sodium‐ion kinetic characteristics to address the challenges. In the heterostructure, the controllable VOC bonds are generated at the interface originating from the chemical conversion of functional groups of the reduced graphene oxides (rGOs) with VO bonding of NVO through interfacial electronic interactions. The interfacial synergistic between the brilliant bonding properties and the inherent formation of a stress field at the heterointerface motivated by work function difference can reduce the Na + diffusion barrier, facilitate charge transfer, hence accelerates reaction kinetics and electron/ion transport, as well as modifying the electronic structure to realize a cherished adsorption energy of Na + . Therefore, the optimized NVO‐NBs‐based heterostructure exhibits exceptional rate capability (213 mAh g −1 at 0.2 C with 100 mAh g −1 at 10 C) and ultralong cycling stability (95.4%, 3000 cycles at 5 C). This work demonstrates that the controllable heterostructure interface with abundant chemical bonds is an effective approach to exploit potential cathodes for rechargeable batteries.