Interface Reversible Electric Field Regulated by Amphoteric Charged Protein-Based Coating Toward High-Rate and Robust Zn Anode

Metallic interface engineering is a promising strategy to stabilize Zn anode via promoting Zn(2+) uniform deposition. However, strong interactions between the coating and Zn(2+) and sluggish transport of Zn(2+) lead to high anodic polarization. Here, we present a bio-inspired silk fibroin (SF) coating with amphoteric charges to construct an interface reversible electric field, which manipulates the transfer kinetics of Zn(2+) and reduces anodic polarization. The alternating positively and negatively charged surface as a build-in driving force can expedite and homogenize Zn(2+) flux via the interplay between the charged coating and adsorbed ions, endowing the Zn-SF anode with low polarization voltage and stable plating/stripping. Experimental analyses with theoretical calculations suggest that SF can facilitate the desolvation of [Zn(H(2)O)(6)](2+) and provide nucleation sites for uniform deposition. Consequently, the Zn-SF anode delivers a high-rate performance with low voltage polarization (83 mV at 20 mA cm(−2)) and excellent stability (1500 h at 1 mA cm(−2); 500 h at 10 mA cm(−2)), realizing exceptional cumulative capacity of 2.5 Ah cm(−2). The full cell coupled with Zn(x)V(2)O(5)·nH(2)O (ZnVO) cathode achieves specific energy of ~ 270.5/150.6 Wh kg(−1) (at 0.5/10 A g(−1)) with ~ 99.8% Coulombic efficiency and retains ~ 80.3% (at 5.0 A g(−1)) after 3000 cycles. [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40820-022-00969-4.