Synthesis and Electrochemical Performance of the Orthorhombic V 2 O 5 · n H 2 O Nanorods as Cathodes for Aqueous Zinc Batteries.

Aqueous zinc-ion batteries offer the greatest promise as an alternative technology for low-cost and high-safety energy storage. However, the development of high-performance cathode materials and their compatibility with aqueous electrolytes are major obstacles to their practical applications. Herein, we report the synthesis of orthorhombic V 2 O 5 · n H 2 O nanorods as cathodes for aqueous zinc batteries. As a result, the electrode delivers a reversible capacity as high as 320 mAh g -1 at 1.0 A g -1 and long-term cycling stability in a wide window of 0.2 to 1.8 V using a mild ZnSO 4 aqueous electrolyte. The superior performance can be attributed to the improved stability of materials, inhibited electrolyte decomposition and facilitated charge transfer kinetics of such materials for aqueous zinc storage. Furthermore, a full cell using microsized Zn powder as an anode within capacity-balancing design exhibits high capacity and stable cycling performance, proving the feasibility of these materials for practical application.