Development of vanadium-based polyanion positive electrode active materials for high-voltage sodium-based batteries

• Published in: Nature communications Vol. 13; no. 1; pp. 4097 - 10
• Main Authors: Shraer, Semyon D, Luchinin, Nikita D, Trussov, Ivan A, Aksyonov, Dmitry A, Morozov, Anatoly V, Ryazantsev, Sergey V, Iarchuk, Anna R, Morozova, Polina A, Nikitina, Victoria A, Stevenson, Keith J, Antipov, Evgeny V, Abakumov, Artem M, Fedotov, Stanislav S
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 14.07.2022; Nature Publishing Group UK; Nature Portfolio
• Subjects: Aqueous electrolytes; Batteries; Chemical synthesis; Configurations; Discharge; Electrode materials; Electrodes; High voltages; Ion exchange; Ion storage; Low temperature; Nonaqueous electrolytes; Playgrounds; Polyelectrolytes; Potassium titanyl orthophosphate; Sodium; Sodium channels (voltage-gated); Solid solutions; Vanadium
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-31768-5

Abstract Polyanion compounds offer a playground for designing prospective electrode active materials for sodium-ion storage due to their structural diversity and chemical variety. Here, by combining a NaVPO 4 F composition and KTiOPO 4 -type framework via a low-temperature (e.g., 190 °C) ion-exchange synthesis approach, we develop a high-capacity and high-voltage positive electrode active material. When tested in a coin cell configuration in combination with a Na metal negative electrode and a NaPF 6 -based non-aqueous electrolyte solution, this cathode active material enables a discharge capacity of 136 mAh g −1 at 14.3 mA g −1 with an average cell discharge voltage of about 4.0 V. Furthermore, a specific discharge capacity of 123 mAh g −1 at 5.7 A g −1 is also reported for the same cell configuration. Through ex situ and operando structural characterizations, we also demonstrate that the reversible Na-ion storage at the positive electrode occurs mostly via a solid-solution de/insertion mechanism.