Construction of Moisture-Stable Lithium Diffusion-Controlling Layer toward High Performance Dendrite-Free Lithium Anode

Spatially random lithium nucleation and sluggish lithium diffusion across the electrode/electrolyte interface lead to uncontrollable lithium deposition and the growth of lithium dendrite on metallic lithium surface, causing severe safety problems. Herein, a functional rapid-ion-diffusion alloy layer on the metallic lithium surface (RIDAL-Li) is designed through a simple chemical reduction reaction. Such a layer efficiently reduces energy barriers for lithium transport and thus significantly homogenizes the lithium atom flux for lateral deposition, which are confirmed by electrochemical tests, theoretical simulations, and spectroscopic analysis. Furthermore, the as-prepared RIDAL layer also displays a much higher corrosion resistance to moisture and oxygen. As a result, in ether-based and carbonate-based electrolytes, the pretreated RIDAL-Li anode can achieve a long stripping/plating lifespan of 900 h and a high Coulombic efficiency of 99% without dendrite growth. Even after being exposed to the ambient environment with relative humidity of 51% for 60 min, the RIDAL-Li can survive for stripping/plating 400 h and exhibit a low overpotential of 18 mV, displaying the superiority for ambient atmosphere battery assembly. Matched with LiFePO4 or sulfur cathode, the full cells exhibit remarkably improved stability and capacity retention, showing its suitability for applications in lithium metal batteries.

Automated summary

The functional rapid-ion-diffusion alloy layer designed in this study efficiently reduces energy barriers for lithium transport and homogenizes the lithium atom flux, improving the safety and stability of lithium metal batteries.