Direct Growth of a Polymer Film to Induce Horizontal Orientation of Zn 4 (OH) 6 SO 4 · x H 2 O for Stable Zn Metal Batteries.

The loose and randomly oriented byproduct (i.e., Zn 4 (OH) 6 SO 4 · x H 2 O, ZHS) in situ formed on the zinc (Zn) surface is recognized to be the primary cause for dendritic Zn growth and side reactions. Switching the detrimental passivation film into a dense and kinetically favorable solid electrolyte interphase (SEI) is a straightforward strategy to tackle these issues faced by Zn metal anodes but remains largely unexplored. Herein, a new polymer film directly grown on Zn metal through room-temperature plasma-enhanced chemical vapor deposition is proposed to induce the lateral growth of ZHS nanosheets and decrease the Zn 2+ desolvation barrier, thereby forming a beneficial composite SEI for suppressing Zn dendrite growth and surface corrosion. As a result of the joint effect, we realize an impressively stable cycling behavior in symmetric cell over 3400 h at 2 mA cm -2 . Moreover, full cells also demonstrate prolonged lifespans. This work opens a new avenue for stabilizing Zn metal batteries by turning detrimental ZHS into a favorable interlayer.