Understanding the Role of Titanium Metal–Organic Framework Nanosheets in Modulating Anode Chemistry for Aqueous Zinc-Ion Batteries
Chao Wang, Qihong Xie, Taolian Guo, Min Fang, Wei Mao, Yuchen Zhang, Haobo Wang, Xinxi Ma, Yutong Wu, Shuang Li, Jie Han
Abstract
Aqueous zinc-ion batteries have attracted a continually increasing level of interest for large-scale energy storage because they are highly safe and have high energy density and abundant reserves. However, Zn anodes face significant challenges such as severe dendrite growth and hydrogen evolution reaction (HER). We here propose an efficient Zn 2+ sieve strategy for modulating the anode chemistry using two-dimensional NH 2 -MIL-125 (Ti) metal–organic framework (MOF) nanosheets. Theoretical investigations reveal the crucial role of the Ti MOF in regulating Zn 2+ solvation structures for fast diffusion and uniform deposition and decreasing HER reactivity. The structure of the nanosheets enables abundant accessible desolvation sites and shortened ionic pathways. As a result, the MOF nanosheet-protected Zn anode exhibited greatly improved cycling stability in both symmetric cells and full cells. Operando optical monitoring and postmortem analysis revealed effective suppression of dendrite growth and HER by Ti MOF nanosheets. This anti-HER MOF-enabled Zn 2+ sieve strategy provides a viable Zn anode and provides new insights for optimizing aqueous batteries.