Construction of zinc metal-Tin sulfide polarized interface for stable Zn metal batteries

Aqueous Zn metal batteries have become competitive electrochemical energy storage systems owing to their material abundance, low cost, high capacity, and nontoxicity. Nevertheless, the notorious Zn dendrites and poor anode reversibility caused by the insulating by-products and "dead Zn" are still formidable challenges for their practical application. Herein, an SnS-based layer coated on the Zn anode is reported to tackle these problems. The semiconducting SnS with a higher work function can drive the electrons from the Zn anode, which constructs a polarized interface between the SnS layer and Zn. The semiconducting importance of the coating layer is verified through theoretical simulations, which can migrate the polarization layer from the electrode surface to a well-protected spot beneath the coating layer. This polarization interface is effective in homogenizing the Zn2+ flux and repelling the anions from electrochemical corrosion. Compared with the bare Zn, the SnS-coated Zn anode exhibits a notable 14.7-fold enhancement in plating/stripping lifetime (over 3000 ​h), high reversibility (with CE of 99.74%), and superior stability in full cells when paired with vanadium- and manganese-based cathodes.