MOF-derived defect-rich CeO2 as ion-selective smart artificial SEI for dendrite-free Zn-ion battery

Abstract

Interface engineering is considered as an effective way to inhibit dendrite growth and side reactions in rechargeable zinc ion batteries (ZIBs). Herein, to explore the best treatment routes on how to construct multi-functional protective layers with MOF-based nanomaterials, defect-rich CeO2 polycrystals are designed with Ce-MOF-808 precursor as ion-selective smart artificial SEI for ZIBs. Interestingly, crystal defects which can provide active sites for Zn2+ transfer, are introduced to MOF-CeO2 via pyrolysis. Furthermore, the negative Zeta potential gives high selectivity to cations and shielding effect to anions, inhibiting the side reactions. Besides, MOF-CeO2 can promote the desolvation process of Zn[(H2O)6]2+ and balance Zn-ion flux by pores. Impressively, synergistic effects on dendrite inhibition by chemical stability, crystal defects, surface charge properties, and hierarchically porous structure are investigated comprehensively. Therefore, MOF-CeO2@Zn anode exhibited ultra-stable plating/stripping behavior (more than 3200 h) and high Coulomb efficiency (99.5 % at 2 mA cm−2). This multi-functional protective layer also significantly improves the overall performance of Zn||MnVO full battery, with high-capacity retention at 5 A/g after 10,000 cycles.