<i>In Situ</i> Molecular Engineering Strategy to Construct Hierarchical MoS₂ Double-Layer Nanotubes for Ultralong Lifespan "Rocking-Chair" Aqueous Zinc-Ion Batteries.

Abstract

Rechargeable aqueous zinc ion batteries (AZIBs) have gained considerable attention owing to their low cost and high safety, but dendrite growth, low plating/stripping efficiency, surface passivation, and self-erosion of the Zn metal anode are hindering their application. Herein, a one-step <i>in situ</i> molecular engineering strategy for the simultaneous construction of hierarchical MoS₂ double-layer nanotubes (MoS₂-DLTs) with expanded layer-spacing, oxygen doping, structural defects, and an abundant 1T-phase is proposed, which are designed as an intercalation-type anode for "rocking-chair" AZIBs, avoiding the Zn anode issues and therefore displaying a long cycling life. Benefiting from the structural optimization and molecular engineering, the Zn²⁺ diffusion efficiency and interface reaction kinetics of MoS₂-DLTs are enhanced. When coupled with a homemade ZnMn₂O₄ cathode, the assembled MoS₂-DLTs//ZnMn₂O₄ full battery exhibited impressive cycling stability with a capacity retention of 86.6% over 10 000 cycles under 1 A g^-1_anode, outperforming most of the reported "rocking-chair" AZIBs. The Zn²⁺/H⁺ cointercalation mechanism of MoS₂-DLTs is investigated by synchrotron <i>in situ</i> powder X-ray diffraction and multiple <i>ex situ</i> characterizations. This research demonstrates the feasibility of MoS₂ for Zn-storage anodes that can be used to construct reliable aqueous full batteries.