biostudies-literatureDe PTECHSCALEERDF/ESFLarge Research Infrastructure ENREGATEuropean Union under the REFRESH-Research Excellence For REgion Sustainability and High-tech IndustriesMinistry of Education, Youth and Sports of the Czech RepublicOperational Programme Just TransitionCzech Nano Labe07255https://www.ebi.ac.uk/biostudies/studies/S-EPMC12499396biostudies-literatureUnknown12(37)The primary scientific challenge in advancing aqueous aluminum-ion batteries (AAIBs) is achieving reversible plating/stripping of the Al metal anode, limited by its low deposition potential (-1.667 V vs SHE) and surface passivation in the aqueous electrolyte. To address this issue, polypyrrole (PPy) decorated topological quantum insulator (Bi₂Te₃@PPy) is introduced as a novel anode in AAIBs. Benefiting from the interconnected PPy network and the gap-free metallic surface state of Bi₂Te₃, the Bi₂Te₃@PPy anode enables a remarkable discharge capacity of 438 mAh g^-1 at a current rate of 0.5 A g^-1. It also maintains a strong discharging plateau even at a higher current rate of 10 A g^-1, outperforming most electrode materials reported so far for AAIBs. The role of the topological surface states of Bi₂Te₃ in enhancing the ion migration rate is validated by comparing its performance across various morphologies. Ex situ studies and computational analysis reveal that in aqueous systems, Al³⁺ is not the sole species responsible for charge storage. Instead, hydronium ions (H₃O⁺) significantly contribute to storing the charges through intercalation into the crystal lattice. Overall, this study pioneers a new approach for developing advanced Al metal-free AAIBs and provides deeper insights into the charge storage mechanisms in aqueous electrolytes.Advanced science (Weinheim, Baden-Wurttemberg, Germany)Topological Insulator Bi<sub>2</sub>Te<sub>3</sub> Anode for Aqueous Aluminum-Ion Batteries: Unveiling the Role of Hydronium Ions.PMC12499396CZ.02.01.01/00/22_008/0004587CZ.10.03.01/00/22_003/0000048LM2023056LM2023051ID:90254De PLazar PPumera MOtyepka MfalseTopological Insulator Bi<sub>2</sub>Te<sub>3</sub> Anode for Aqueous Aluminum-Ion Batteries: Unveiling the Role of Hydronium Ions.The primary scientific challenge in advancing aqueous aluminum-ion batteries (AAIBs) is achieving reversible plating/stripping of the Al metal anode, limited by its low deposition potential (-1.667 V vs SHE) and surface passivation in the aqueous electrolyte. To address this issue, polypyrrole (PPy) decorated topological quantum insulator (Bi₂Te₃@PPy) is introduced as a novel anode in AAIBs. Benefiting from the interconnected PPy network and the gap-free metallic surface state of Bi₂Te₃, the Bi₂Te₃@PPy anode enables a remarkable discharge capacity of 438 mAh g^-1 at a current rate of 0.5 A g^-1. It also maintains a strong discharging plateau even at a higher current rate of 10 A g^-1, outperforming most electrode materials reported so far for AAIBs. The role of the topological surface states of Bi₂Te₃ in enhancing the ion migration rate is validated by comparing its performance across various morphologies. Ex situ studies and computational analysis reveal that in aqueous systems, Al³⁺ is not the sole species responsible for charge storage. Instead, hydronium ions (H₃O⁺) significantly contribute to storing the charges through intercalation into the crystal lattice. Overall, this study pioneers a new approach for developing advanced Al metal-free AAIBs and provides deeper insights into the charge storage mechanisms in aqueous electrolytes.2025-01-01T00:00:00Z2025 Oct2026-06-05T06:31:19.432Z2026-06-05T03:06:42.652ZS-EPMC124993964061960010.1002/advs.202507255