Glucose intercalation-induced 1T-G-MoS2 hybrids for high-performance rechargeable aqueous zinc-ion batteries

Abstract

Owing to 1T phase MoS₂ (1T-MoS₂) possessing higher electron conductivity than 2H phase MoS₂ (2H-MoS₂), 1T-MoS₂ is considered as a more promising electrode material for aqueous zinc-ion batteries (AZIBs). Herein, a glucose intercalation-assisted induction strategy is employed to prepare stable 1T-rich MoS₂ hybrids (1T-G-MoS₂) for boosting zinc storage performance. The glucose is intercalated into MoS₂ through a one-step facile hydrothermal method, which expands the interlayer spacing and improves the hydrophilicity, facilitating reversible insertion/extraction kinetics of Zn²⁺ ions. Density functional theory (DFT) calculations indicate that the intercalated glucose can donate electrons to the Mo atoms, triggering reorganization of the Mo 4d orbitals and inducing phase transformation of MoS₂ from 2H to 1T phase, thereby increasing the electron conductivity of MoS₂ and promoting electron transfer. The enhanced electron and ion transfer as well as the more exposed active sites accelerate the reaction kinetics, leading to an improved electrochemical performance for AZIBs. The obtained 1T-G-MoS₂ electrode exhibits a high discharge capacity of 192.62 mA h g⁻¹ at 0.1 A g⁻¹ and superior rate performance. Moreover, the enlarged interlayer spacing alleviates changes in the volume of 1T-G-MoS₂ during the discharging/charging processes, giving it excellent cycling stability. The capacity retention can still reach 71.98% even after 500 cycles at 1 A g⁻¹. This work deeply investigates the MoS₂ phase transformation mechanism and its effect on the reaction kinetics, providing a promising solution for high-performance MoS₂-based AZIBs.