Nanohybrid engineering of the vertically confined marigold structure of rGO-VSe2 as an advanced cathode material for aqueous zinc-ion battery

Abstract

The development of Zinc-ion batteries (ZIBs) has been in focus for quite some time compelled by poor effectiveness and lower cycle stability, primarily due to slow ion diffusion kinetics and design deformity of cathode materials. Developing innovative cathode materials with high conductivity and stability may be an alternative means of solving these issues. Here, a basic one-step hydrothermal approach is used to synthesize marigold-like reduced graphene oxide (rGO) and VSe2 nanohybrids. The highly conductive rGO wraps VSe2 to suppress the electrostatic stacking of nanosheets, and at the same time serves as a template to form a marigold-like nanohybrid structure. Moreover, the diffusion path of electrolyte ions is reduced and the strongly conductive graphene provides a 3D highway for electron transfer with improved reaction kinetics. The rGO- VSe2 nanohybrid was used as a cathode for ZIBs, which exhibited a good reversible potential of 221.5mAhg−1 at 0.5 A g−1, and has excellent conversion efficiency with good cycling stability (~91.6% retention after 150 cycles). These empowering developments provide a better way to explore high-capacity, high-performance electrode materials.