K ₂V ₆O ₁₆·2.7H ₂O nanorod cathode: an advanced intercalation system for high energy aqueous rechargeable Zn-ion batteries

Abstract

Layered K ₂V ₆O ₁₆·2.7H ₂O nanorod cathode, utilized for aqueous rechargeable Zn-ion batteries, displays high reversible capacities, exceptional rate capabilities and long cycle-span of 700 (altering three different current densities) and 500 (~82% capacity retention at 6 A g ⁻¹) cycles.

Abstract

1D nanorods of the layered material K ₂V ₆O ₁₆·2.7H ₂O (KVO) are implemented for the first time as cathode materials in secondary aqueous rechargeable Zn-ion batteries (ARZIBs) and exhibit excellent electrochemical Zn storage properties. This cathode material delivers a reversible capacity of 296 mA h g ⁻¹ over 100 cycles. At current densities of 1000, 3000, and 5000 mA g ⁻¹ for 700 cycles, the electrode displays reversible capacities of 223, 177, and 138 mA h g ⁻¹, for approximately 170, 300, and 230 cycles, respectively. In addition to these properties, it withstands over 500 cycles at an applied current density of 6000 mA g ⁻¹ with nearly 82% capacity retention. The battery offers a specific energy of 128 Wh kg ⁻¹ at a specific power of 5760 W kg ⁻¹, revealing the advantages of the material in an eco-friendly atmosphere.