Constructing advanced vanadium oxide cathode materials for aqueous zinc-ion batteries via the micro-nano morphology regulation strategies

High-safety and low-cost aqueous zinc ion batteries (ZIBs) have gained much attention for the electrochemical energy storage system. However, ZIBs still face severe challenges in achieving long-cycle performance and excellent rate performance, which are limited by poor material stability and conductivity by cathode materials. Herein, a novel layered hydrated vanadates composite material embedded in highly conductive reduced graphene oxide (rGO) scaffolds is prepared by diversified synthesis strategies of micro-nano morphology regulation. With the assistance of different amounts of sodium dodecyl sulfate (SDS), the morphologies are transformed from nano polyhedrons to nanoribbons, and a possible formation mechanism is correspondingly proposed. Furthermore, the unique structure and morphology, together with consequent rapid Zn2+ transport dynamics and structural stability are significant to the superior energy storage performance. As expected, the CoVO-150 provides a high reversible specific capacity of 230.3 mAh g−1 at 5 A g−1, while it provides remarkable capacity retention of 82.1 % at 20 A g−1 after 2000 cycles. This article provides an effective strategy for the development and optimization of novel cathode materials for a high-performance zinc ion energy storage system.