MOF-modified dendrite-free gel polymer electrolyte for zinc-ion batteries.

Zinc-ion batteries are promising candidates for large-scale energy storage, and gel polymer electrolytes (GPEs) play an important role in zinc-ion battery applications. Metal-organic frameworks (MOFs) are characterized by large specific surface areas and ordered pores. This highly ordered microporous structure provides a continuous transport channel for ions, thus realizing the high-speed transmission of ions. In this paper, an MOF-modified dendrite-free GPE was designed. The incorporation of MOF particles not only reduces the crystallinity of the polymer, increases the motility of the molecular chains, and facilitates the transfer of Zn, but also attracts anions to reduce polarization during electrochemical reactions. It was shown that this MOF-modified gel polymer electrolyte has a higher ionic conductivity compared to other PVDF-based polymer electrolytes (approximate range of 2 × 10 to 3 × 10 S cm), with a very high conductivity (1.63 mS cm) even at -20 °C. The Zn/Zn symmetric cell could maintain operation for more than 3600 h at a current density of 1 mA cm, and SEM showed that the MOF-modified gel electrolyte had uniform Zn deposition.