Publication

Operando pH measurements decipher H⁺/Zn²⁺ Intercalation chemistry in high-performance aqueous Zn/δ-V₂O₅ Batteries

Autors: Xu Liu, Holger Euchner, Maider Zarrabeitia, Xinpei Gao, Giuseppe Antonio Elia, Axel Groß and Stefano Passerini.

Summary: Vanadium oxides have been recognized to be among the most promising positive electrode materials for aqueous zinc metal batteries (AZMBs).To shed light on the intercalation mechanisms, high-performance δ-V₂O₅ is investigated as a model compound. An operando pH determination method is developed and used toward Zn/δ-V₂O₅ AZMBs. This method indicates the intercalation of both H⁺ and Zn²⁺ into δ-V₂O₅ and uncovers an unusual H⁺/Zn²⁺-exchange intercalation–deintercalation mechanism. Density functional theory calculations further reveal that the H⁺/Zn²⁺ intercalation chemistry is a consequence of the variation of the electrochemical potential of Zn²⁺ and H⁺ during the electrochemical intercalation/release.

Link: https://doi.org/10.1021/acsenergylett.0c01767