Pre‐Intercalation of TMA Cations in MoS₂ Interlayers for Fast and Stable Zinc Ion Storage

Abstract

Applications of aqueous zinc ion batteries (ZIBs) for grid‐scale energy storage are hindered by the lacking of stable cathodes with large capacity and fast redox kinetics. Herein, the intercalation of tetramethylammonium (TMA+) cations is reported into MoS2 interlayers to expand its spacing from 0.63 to 1.06 nm. The pre‐intercalation of TMA+ induces phase transition of MoS2 from 2H to 1T phase, contributing to an enhanced conductivity and better wettability. Besides, The calculation from density functional theory indicates that those TMA+ can effectively shield the interactions between Zn2+ and MoS2 layers. Consequently, two orders magnitude high Zn2+ ions diffusion coefficient and 11 times enhancement in specific capacity (212.4 vs 18.9 mAh g‒1 at 0.1 A g‒1) are achieved. The electrochemical investigations reveal both Zn2+ and H+ can be reversibly co‐inserted into the MoS2‐TMA electrode. Moreover, the steady habitat of TMA+ between MoS2 interlayers affords the MoS2‐TMA with remarkable cycling stability (90.1% capacity retention after 2000 cycles at 5.0 A g‒1). These performances are superior to most of the recent zinc ion batteries assembled with MoS2 or VS2‐based cathodes. This work offers a new avenue to tuning the structure of MoS2 for aqueous ZIBs.

Highly Reversible and Dendrite-Free Zinc Anodes Enabled by PEDOT Nanowire Interfacial Layers for Aqueous Zinc-Ion Batteries

“…Aqueous zinc-ion batteries (ZIBs) are considered as one of the promising electrochemical energy storage systems because of the high theoretical capacity of metal Zn (820 mAh g –1 or 5855 mAh cm –3 ), relatively low redox potential (−0.76 V vs SHE), natural abundance of zinc, and good operational safety. − However, the cycling stability of ZIBS strongly depends on the properties of zinc anodes, which are facing a series of formidable issues including uncontrollable Zn dendrites, chemical corrosion from irreversible consumption of Zn metal, and hydrogen evolution induced by aqueous electrolytes. − These issues lower the reversibility of the zinc anode and hinder future applications of ZIBs in grid-scale energy storage.…”