Self-assembled polysilane artificial solid electrolyte interphase layer towards highly reversible zinc electrochemistry

Abstract

Commercial applications of aqueous Zn batteries primarily encounter challenges related to surface corrosion and dendrite formation. In this study, a hydrophobic polysilane layer functionalized with −CF3 groups (CF3-PSiOX) is tailored for Zn anode through a two-step process involving self-assembly and condensation. The CF3-PSiOX layer functions as a protective barrier, effectively isolating water and inhibiting corrosion. Moreover, the primary interactions between −CF3 and Zn2+ guides the diffusion and deposition processes of Zn2+ while optimizing the de-solvation process, ultimately resulting in dendrite inhibition. Hence, cells with CF3-PSiOX layer boasts a high Coulombic efficiency (∼99.8 % after 1500 cycles), a long lifespan (over 2400 h), and optimized capacity retention (73.3 % over 1000 cycles). The self-assembled polysilane layer with customizable groups offers a novel approach for tuning the interface properties of Zn anodes and establishes a general principle for interface adjustment applicable to alternative metallic electrodes.