Comprehensive Analysis of Aqueous Aluminum–Zinc Hybrid Ion Batteries Based on Zinc Anode and Aluminum-Based Electrolyte

The insulating alumina layer on aluminum anodes significantly hinders their reversibility in AAIBs. Although substituting aluminum with active metals (Li, K, Ca, Na, Mg, Zn, Sn, and Pb) offers a solution, systematic comparisons of their plating/stripping behavior in aluminum-based electrolytes are scarce. We comprehensively evaluate metal anodes, electrolytes (1 M AlCl3, 1 M Al(NO3)3, 1 M Al(ClO4)3 and 0.5 M Al2(SO4)3), and separators (glass fiber, cellulose) to optimize interfacial performance. The Zn anode with 0.5 M Al2(SO4)3 electrolyte and cellulose separator shows remarkable stability, demonstrating low polarization (<0.2 V) and extended cycling (>1000 h) in symmetric cells. Additionally, the assembled Zn/0.5 M Al2(SO4)3/polyaniline hybrid battery achieves high capacity (∼294 mAh g–1) and discharge voltage (∼1.3 V), establishing a material selection framework for advanced aqueous multivalent-ion batteries.