Suppressing hydrogen evolution and promoting dendrite free zinc deposition by fluorinated triazine framework towards robust aqueous zinc ion batteries.

ABSTRACT

Aqueous zinc-ion batteries (AZIBs) have become a research hotspot, but the inevitable zinc dendrites and parasitic reactions in the zinc anode seriously hinder their further development. In this study, three covalent triazine frameworks (DCPY-CTF, CTF-1 and FCTF) have been synthesized and used as artificial protective coatings, in which the fluorinated triazine framework (FCTF) increases the zinc-philic site, thus better promoting dendritic free zinc deposition and inhibiting hydrogen evolution reactions. Excitingly, both experimental results and theoretical calculations indicate that the FCTF interface adjusts the deposition of Zn2+ along the (002) plane, effectively alleviating the formation of zinc dendrites. As expected, Zn@FCTF symmetric cells exhibit cycling stability of over 4000 h (0.25 mA cm-2), meanwhile Zn@FCTF//NHVO full cells provide a high specific capacity of 280 mAh/g at 1.0 A/g, which are superior to those of bare Zn anode. This work provides new insights for suppressing hydrogen evolution and promoting dendrite-free zinc deposition to construct highly stable and reversible AZIBs.