Homogeneous Zn2+ flux and rapid ion-transport kinetics for highly reversible Zn anodes based on Fluorapatite aerogels interfacial engineering

Abstract

The low invertibility of Zn-based electrodes actuated with corrosion, surface passivation as well as dendrite growth seriously limits the commercial usability of Zn-based batteries. In this study, the above-mentioned issues have been addressed using fluorapatite aerogel (FA) interfacial engineering, which has been proposed for the development of a high-performance ion-transport modulator that offers the ability to concurrently promote ion-transport kinetics and regulate uniform Zn2+ flux. The FA layer with an ordered mesoporous structure was employed as an ion-sieve to achieve homogenous deposition of Zn and acceleration of the Zn2+ flux. This strategy proved quite useful in suppressing the growth of dendrites as well as enhancing corrosion resistance. Importantly, the aerogel with the lightweight feature interlayer contains abundant ion-transport channels that facilitate the Zn2+ ion-transport kinetics. Also, a Zn/Zn cell was constructed using the FA-modified separator that displayed stable stripping and plating operation (exceeding 1000 h for a current density (Id) equal to 1 mA cm−2), attaining a Coulombic efficiency value as high as 99.8 % at Id = 1 mA cm−2 following 100 cycles. Additionally, the prepared Zn||MnO2 battery exhibited outstanding long cyclic stability while maintaining a large capacity of 154.9 mA h g−1 following 1000 cycles at 1 A g−1. This article thus presents a viable strategy for the mass production of separators functionalized using aerogel for the realization of ultra-stable Zn metal batteries.