Engineering a High-Strength and Superior-Electrolyte-Wettability Silk Fibroin-Based Gel Interface Achieving Dendrite-Free Zn Anode.

Zn metal anode is confronted with notorious Zn dendrite growth caused by inhomogeneous Zn deposition, rampant dendrite growth, and serious interface side reactions, which significantly hinder their large-scale implication. Interface modification engineering is a powerful strategy to improve the Zn metal anode by regulating Zn deposition behavior, suppressing dendrite formation, and protecting the anode from electrolyte corrosion. Herein, we have designed a high-strength and superior-electrolyte-wettability composite gel protective layer based on silk fibroin (SF) and ionic liquids (ILs) on the Zn anode surface by a straightforward spin-coating strategy. The Zn ion transport kinetics and mechanical properties were further improved by following the incubation process to construct a more well-ordered β-sheet structure. Consequently, the incubated composite gel coating serves as a command station, guiding the Zn ion's preferential growth along the (002) plane, resulting in a smooth and uniform deposition morphology. Driven by these improvements, the zinc anode modified with this composite gel exhibits a remarkably long-term cycling lifespan up to 2200 h at 2 mA cm, while also displaying superior rate capability. This study represents a landmark achievement in the realm of electrochemical science, delineating a clear pathway toward the realization of a highly reversible and enduring Zn anode.