Improved rate and cycling capability of V2O5@MoS2 nanocomposites as an advanced cathode material for rechargeable aqueous zinc-ion batteries

Abstract

Owing to the benefits of higher energy density, reliable safety, and eco-friendliness, rechargeable aqueous zinc (Zn)-ion batteries (RAZIBs) are employed in energy storage applications. Nevertheless, the enhancement of potential cathodes is hindered by low reversibility and sluggish Zn-ion diffusion kinetics, causing deficient rate capability and modest cycling performance. Vanadic anhydride (V2O5) provides a potential in RAZIBs from its layered structure and superior capacity. Herein, molybdenum disulfide (MoS2) was combined into the V2O5 to form V2O5@MoS2 nanocomposites (NCs) via a simple hydrothermal method. The V2O5@MoS2 NCs enable Zn ions to migrate effectively between layers and stabilize volume changes during the insertion/extraction process. Moreover, the presence of MoS2 as a mediator in the framework produces additional defects, which leads to an enhanced storage area for Zn ions. The optimized V2O5@MoS2–2 NCs exhibited a cycling capacity of 230.74 mA h g−1 at 0.5 A g−1, superior rate performance (73.59 mA h g−1 at 30 A g−1), and excellent long-term cycling stability (108.16 mA h g−1 at 10 A g−1 over 6000 cycles), surpassing those of V2O5@MoS2–1, V2O5@MoS2–3, V2O5, and MoS2 counterparts. Such fascinating properties reveal that the proposed composite materials as a progressive cathode for RAZIBs.