Interfacial Zn ion capture and desolvation engineering for high-performance Zn metal anode

The uneven surface of planar zinc (Zn) metal anodes fundamentally reduces the electrochemical reversibility of aqueous Zn metal batteries due to dendritic growth. Herein, an interphase protection layer engineering is formed on the surface of the Zn metal anode through a solution-processed coating method. This interesting carbon layer, composed of carbon nanoparticles obtained from outer flame-derived candle soot (OFCS), exhibits excellent Zn ion capturing and storage capabilities, effectively reducing the accumulation of charge density on the Zn metal surface, providing a homogeneous Zn ion flux and inducing even Zn metal deposition. The OFCS@Zn can promote the desolvation of [Zn(H2O)6]2+ through strong interaction with Zn ions, mitigating corrosion and hydrogen evolution reactions. The multifunctional integration of the OFCS layer synergistically induces uniform Zn metal plating and inhibits side reactions. Consequently, in the OFCS @Zn | OFCS @Zn symmetric-cell tests, high-rate performance and deep charge/discharge capabilities are demonstrated. The OFCS@Zn anode-based pouch cell exhibits a high discharge capacity of 156.2 mAh g-1 and maintains a significant capacity retention rate of 95.4 % for 200 cycles at the current density of 1 A g-1, indicating its potential for enhanced battery stability and efficiency.