Aqueous zinc-ion batteries (AZIBs) hold great promise for large-scale energy storage; however, their development is hindered by Zn anode instability, including dendrite growth, parasitic hydrogen evolution, and interfacial passivation. Here, we report a low-cost and scalable composite separator (GB50-ZrO2-40) fabricated by ball milling and vacuum filtration of glass fiber, bacterial cellulose (BC), and 40 wt % ZrO2 nanoparticles. The resulting three-phase network exhibits high mechanical strength (∼44 MPa), hierarchical porosity, and strong water/ZrO2 interactions, which together provide multiple functions: it resists dendrite penetration through mechanical reinforcement, homogenizes the local electric field and Zn2+ flux via interfacial Maxwell-Wagner polarization, and promotes partial desolvation of Zn2+ by preferential water adsorption on ZrO2. These synergistic effects inhibit side reactions and promote uniform, dense Zn deposition. As a result, Zn||Zn symmetric batteries with GB50-ZrO2-40 deliver ultrastable cycling performance exceeding 4500 h at 0.5 mA cm-2 with 0.25 mAh cm-2 and 1307 h at 10 mA cm-2 with 5 mAh cm-2. Furthermore, Zn||NaV3O8·1.5H2O full batteries retain more than 92% of their capacity after 1000 cycles at 5 A g-1. The underlying mechanisms are supported by combined electrochemical measurements, in situ microscopy, finite-element simulations, and density functional theory (DFT) adsorption calculations, highlighting the practical scalability of the GB50-ZrO2-40 separator for high-performance AZIBs.
Huang et al. (Thu,) studied this question.