Self-Zincophilic Dual Protection Host of 3D ZnO/Zn⊂CF to Enhance Zn Anode Cyclability.

Abstract

Zn dendrite growth and side reactions restrict the practical use of Zn anode. Herein, the design of a novel 3D hierarchical structure is demonstrated with self-zincophilic dual-protection constructed by ZnO and Zn nanoparticles immobilized on carbon fibers (ZnO/Zn⊂CF) as a versatile host on the Zn surface. The unique 3D frameworks with abundant zinc nucleation storage sites can alleviate the structural stress during the plating/stripping process and overpower Zn dendrite growth by moderating Zn2+ flux. Moreover, given the dual protection design, it can reduce the contact area between active zinc and electrolyte, inhibiting hydrogen evolution reactions. Importantly, density functional theory calculations and experimental results confirm that the introduced O atoms in ZnO/Zn⊂CF enhance the interaction between Zn2+ and the host and reduce Zn nucleation overpotential. As expected, the ZnO/Zn⊂CF-Zn electrode exhibits stable Zn plating/stripping with low polarization for 4200h at 0.2mAcm-2 and 0.2 mAhcm-2 . Furthermore, the symmetrical cell displays a significantly long cycling life of over 1800h, even at 30mAcm-2 . The fabricated full cells also show impressive cycling performance when coupled with V2 O3 cathodes.