Dynamically assembled bionic ion pumps interface towards high-rate and cycling stable zinc metal batteries

Abstract

The application of Zn metal anode in aqueous zinc metal batteries (AZMBs) is limited by unstable interface, which induced notorious dendrite growth and corrosion. In this report, a bionic ion pumps interface for Zn metal anode is proposed and constructed by dynamically assembling acetylated protein (α-HPace) (Zn@BIPI/α-HPace). The α-HPace with abundant amide bonds is preferentially assembled on the fresh Zn metal surface as interface, due to its strong recognition of Zn2+. It is demonstrated by TOF-SIMS that the organic -CONH- and inorganic ZnF2/ZnS are the uniformly dispersed section of interface film, played as Zn2+ transport sites and dense barrier layer respectively. Thus, the bionic ion pumps interface is not only beneficial to rapid transport of Zn2+ but also effective to prevent aqueous electrolyte erosion. More importantly, the Zn@BIPI/α-HPace anode achieves uniform deposition with absolute predominant orientation of 91% (100) planes. As improved results, the symmetric cell with Zn@BIPI/α-HPace electrode achieves a long cycle life of over 6000 h, and the full cell with Zn@BIPI/α-HPace anode and NaV3O8-1.5H2O cathode exhibits a high-capacity retention of ~92% after 5000 cycles at 5 A g-1. This study of achieving bionic ion-pump interface engineering provides a novel approach to facilitate the practical application of AZMBs.