A nano interlayer spacing and rich defect 1T-MoS 2 as cathode for superior performance aqueous zinc-ion batteries

Abstract

A simple hydrothermal method is used to synthesize molybdenum disulfide with nano-level interlayer spacing, which effectively improves the zinc storage performance as a cathode electrode in aqueous zinc-ion batteries. Aqueous Zn-ion batteries (ZIBs) are considered very promising alternatives to lithium-ion batteries. However, the low reversibility and slow diffusion of zinc ions in the positive electrode limit their commercial applications. Herein, we successfully prepared the metallic 1T phase of MoS 2 (1T-MoS 2 ) with a nano interlayer spacing of 1.025 nm through a simple one-step hydrothermal method, and used it as a cathode in ZIBs. By adjusting the hydrothermal temperature, the crystallinity and Zn 2+ storage capacity of MoS 2 as a cathode for ZIBs are effectively improved. MoS 2 had the most favorable structure when the hydrothermal temperature was 200 °C, such as larger layer spacing and more lattice distortion. When employed as a cathode, 200-MoS 2 exhibited a considerable specific capacity of 125 mA h g −1 at the current density of 2 A g −1 and high capacity retention of 100% after 500 cycles. This strategy provides a new option for improving the performance of the layered structure as an aqueous zinc ion battery.