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

Abstract

Metallic interface engineering is a promising strategy to stabilize Zn anode via promoting Zn2+ uniform deposition. However, strong interactions between the coating and Zn2+ and sluggish transport of Zn2+ 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 Zn2+ and reduces anodic polarization. The alternating positively and negatively charged surface as a build-in driving force can expedite and homogenize Zn2+ 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(H2O)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 ZnxV2O5·nH2O (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.

Engineering a Ni–Al Brucite-Based Interface Layer with Regulated Zn2+ Flux for Highly Reversible Zn Metal Anodes

“…As shown in Figure d, NA- X @Zn exhibits a smaller R ct than bare Zn, revealing the improvement of charge-transfer kinetics due to the high Zn 2+ conductivity. Particularly, the use of NA-2 enables symmetric cells to achieve the lowest R ct of 175.5 Ω (14 times smaller than bare Zn), suggesting the enhanced Zn 2+ kinetics due to the hydrophilic and zincophilic inorganic layer. , …”

“…Particularly, the use of NA-2 enables symmetric cells to achieve the lowest R ct of 175.5 Ω (14 times smaller than bare Zn), suggesting the enhanced Zn 2+ kinetics due to the hydrophilic and zincophilic inorganic layer. 20,25 The impact of the NA-X LDH protective layer on the reversibility of Zn plating/stripping is further investigated by a symmetric cell. Typically, long-term cycling at low current densities imposes higher demands on the interfacial stability of Zn anodes.…”

“…Though lots of efforts have been devoted, the current performance of the Zn anode is still unsatisfactory, especially under severe current density operation . Besides, some protective layers usually impede the diffusion of Zn 2+ , inevitably leading to an increase in internal impedance . Therefore, developing a Zn 2+ flux-regulated artificial interfacial layer that keeps intimate contact with the Zn surface to regularize the plating/stripping behavior remains a tough challenge.…”

Trace Amounts of Triple-Functional Additives Enable Reversible Aqueous Zinc-Ion Batteries from a Comprehensive Perspective

“…For instance, cationic additives such as TBA + , Li + , and Sc 3+ were introduced into electrolytes, in which cations preferentially adsorbed on the Zn anode surface, providing a shielding effect to homogenize electric field and suppress dendrite growth [ 20 – 22 ]. Building an artificial solid electrolyte interphase (SEI) has been considered as another effective remedy to alleviate side reactions [ 23 – 27 ]. For example, various SEIs including COFs, poly(vinyl butyral), and zinc silicate have been coated on Zn anode surface to block the direct chemical or electrochemical reactions between Zn anode and electrolyte [ 28 – 30 ].…”

Periodically Alternating Electric Field Layers Induces the Preferential Growth of Zn (002) Plane for Ultralow Overpotential Zinc‐Ion Batteries

“…Chao et al developed an amphiphilic charge silk fibroin (SF) coating. [8] The negative charge of the surface accelerates Zn 2+ transport and homogenizes ion flux. Meanwhile, the positive charge can accelerate the de-solvation of [Zn(H 2 O) 6 ] 2+ and provide nucleation sites for uniform Zn 2+ deposition.…”