Exploring the influence of MIL-101(Cr) morphologies on the efficacy of cellulose separators for zinc ion battery performance

The formation of zinc dendrites and by-products significantly affects the cycling performance of aqueous zinc-ion batteries (AZIBs). This study presents the first application of MIL-101(Cr) as a separator material in AZIBs, investigating the impact of various MIL-101(Cr) morphologies in cellulose-based separators on battery performance. The findings demonstrate that separators incorporating spherical MIL-101(Cr) morphology considerably enhance ion conductivity and the transport rate of Zn 2+ ions while effectively inhibiting corrosion reactions and dendrite growth. Notably, the spherical MIL-101(Cr)-based separator exhibited more than double the cycle life of Zn//Zn symmetric cells compared to those made from octahedral and nano-fusion morphologies, achieving over 750 h of operation. Additionally, a Zn//MnO₂ full cells utilizing this separator achieved a remarkable capacity retention of 83.6 % after 400 cycles, with a close-to-100 % Coulombic efficiency. This research underscores the critical role of MIL-101(Cr) morphology in enhancing the performance of AZIB separators, paving the way for innovative designs in future metal-organic framework (MOF)-based separators.