Vanadium acid zinc induced by electrochemical self-optimization of oxygen-defect-rich vanadium trioxide with dual-types of carbon hybridization for accelerating zinc storage dynamics

Rechargeable aqueous zinc ion batteries (ZIBs) are considered as the promiseful device for ultrafast and ultrastable charge storage owing to the cost-efficient, non-flammability, and impressive theoretical specific capacity of zinc metal anodes. However, it suffers from either low energy/power density or inferior cycling stability owing to the lack of suitable cathode materials, especially the prospective cathode candidates with satisfactory capacity and remarkable cycling stability. Herein, we design an oxygen-defect-rich vanadium trioxide with dual-types of carbon hybridization (CNPs/H-V2O3-m/CSs), and an electrochemical self-optimization strategy is utilized to unlock the activity of initial CNPs/H-V2O3-m/CSs cathode. Meanwhile, the investigations of electrochemical self-optimization and reaction mechanism reveal that the CNPs/H-V2O3-m/CSs is transformed into an active CNPs/H-ZnxV2O5-z⋅nH2O/CSs with highly reversible structure during optimization process. As a result, electrochemical self-optimized cathode manifests admirable Zn2+ storage performance with ultrahigh reversible capacities of 567 and 338 mAh g−1 at 0.5 and 16 A g−1 and an exceptional cyclability of 174 mAh g−1 even at 10 A g−1 after 1000 cycles is achieved. Furthermore, the flexible quasi-solid-state batteries are constructed by substituting the traditional aqueous electrolyte with quasi-solid-state gel electrolyte, which exhibited strong bending durability and effectively solved the problem of electrolyte leakage. With these merits, this study is considered as critical step in the development ZIBs and portable/wearable electronics.