Artificial solid-electrolyte interface facilitating uniform Zn deposition by promoting chemical adsorption

Abstract

Zn-air batteries are promising energy storage and conversion systems to replace the conventional lithium-based ones. However, their applications have been greatly hindered by the formation of Zn dendrites and ZnO passivation layer on the Zn anodes. Herein, we report the fabrication of an artificial protective layer comprised of N-doped threedi-mensional hollow porous multi-nanochannel carbon fiber with well-dispersed TiO2 nanoparticles (HMCNF). The incorporated TiO2 nanoparticles and N dopants improve the ion flux distribution and promote the surface adsorption, facilitating the interfacial pseudocapacitive behaviors during Zn deposition. The hierarchical architecture also induces homogenous electric field distribution at the anode/electrolyte interface. Accordingly, the deposition behavior of Zn is regulated, giving rise to enhanced utilization and rechargeability of Zn. When integrated in alkaline Zn-air batteries, the HMCNF-coated Zn anodes exhibit improved electrochemical performances relative to those with the bare Zn anodes, demonstrating a versatile strategy to boost energy storage of metal anodes through optimizing surface adsorption properties.