Stabilizing Zinc Anodes via MoS2/Biomass-Derived Carbon Composite toward High-Performance Aqueous Zinc-Ion Batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) have garnered extensive attention owing to their advantages of low cost, high safety, and environmental friendliness. However, the zinc anode suffers from several critical issues during charge–discharge cycles, such as zinc dendrite growth, electrolyte corrosion, and hydrogen evolution side reactions, which drastically degrade the Coulombic efficiency and cycle life of the batteries. Biomass-derived carbon (BC) materials are particularly attractive because of their abundance, low cost, and diverse functional groups. In this study, a composite coating material (MoS2/BC) is synthesized via a hydrothermal method and applied to the surface of zinc anodes for the AZIBs. The MoS2 nanoflowers assembled from two-dimensional (2D) nanosheets and anchored on flaky BC can significantly expand the interfacial area and enhance the reaction activity. Furthermore, the stacking of multilayered MoS2 nanosheets can effectively improve the mechanical strength of the material, maintain the structural stability of the coating during cycling, and prevent battery failure caused by the peeling off of the coating during long-term charge–discharge cycles. Additionally, the interlayer spacing of MoS2 nanosheets can induce the intercalation of hydrated Zn2+ ions, thus promoting uniform deposition of zinc. The corresponding symmetric cell achieves stable cycling for 2600 h at a current density of 1 mA cm–2 and an areal capacity of 0.15 mAh cm–2. When assembled into a full cell, it maintains a capacity retention rate of 71.0% after 2400 cycles at a high current density of 3 A g–1 with a relatively high initial discharge capacity.