Zwitterionic Bifunctional Layer for Reversible Zn Anode

A Zn metal anode suffers from severe dendrite issues and passivebyproducts, which restrict the practical application of Zn-ion batteries. Herein, abifunctional poly zwitterionic ionic liquid (PZIL) is designed as a new ion-migrationlayer to suppress Zn dendrites and side reactions. On one hand, the zwitterionicfunctional groups on the PZIL layer guide the Zn ion distribution to regulate thedeposition behavior of Zn. On the other hand, the tight bond between zwitterionicgroups and water molecules can build an H2O-poor interface on the surface of the Znanode to avoid side reactions. Based on the above two functions, a symmetrical cell withthe PZIL-layer-modified Zn exhibits a stable plating/stripping performance (2600 h at 1mA cm-2) with low reversible deposition potential (similar to 50 mV). The concept of azwitterionic bifunctional layer will open up a new avenue for reversible anodes for Zn-ion batteries as well as other batterysystems.

Automated summary

A bifunctional poly zwitterionic ionic liquid (PZIL) is designed as a new ion-migration layer to suppress Zn dendrites and side reactions. By guiding the distribution of Zn ions and forming a water-poor interface, it enables stable and reversible performance of Zn-ion batteries.