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Reversible facile Rb+ and K+ ions de/insertion in a KTiOPO4-type RbVPO4F cathode materialстатья
Статья опубликована в высокорейтинговом журнале
Статья опубликована в журнале из списка Web of Science и/или Scopus- Авторы: Fedotov Stanislav S., Samarin Aleksandr Sh, Nikitina Victoria A., Aksyonov Dmitry A., Sokolov Sergey A., Andriy Zhugayevych, Stevenson Keith J., Khasanova Nellie R., Abakumov Artem M., Antipov Evgeny V.
- Журнал: Journal of Materials Chemistry A
- Год издания: 2018
- Издательство: Royal Society of Chemistry
- Местоположение издательства: United Kingdom
- DOI: 10.1039/C8TA03839B
- Аннотация: In this paper, we report on a novel RbVPO4F fluoride phosphate, which adopts the KTiOPO4 (KTP) type structure and complements the AVPO4F (A = alkali metal) family of positive electrode (cathode) materials for metal-ion batteries. RbVPO4F was synthesized via a freeze-drying assisted solid-state route and characterized via structural, computational and electrochemical methods. RbVPO4F represents the first example of reversible electrochemical Rb+ de/insertion in a crystalline oxypolyanionic framework. The electrochemical measurements on RbVPO4F in a three-electrode cell configuration in RbClO4-saturated propylene carbonate (PC) electrolyte revealed that the material exhibits reversible Rb+ de/insertion within the 0.4-1.3 V vs. Ag+/Ag potential range (~3.9-4.8 V vs K+/K) displaying rather high diffusion coefficients of (0.3-1.0) 10-11 cm2/s comparable to those of K+ in KVPO4F that supports reasonably fast ionic mobility in the KTP structure despite the large ionic radius of the Rb+ ions. The energy barriers of Rb+ ion transport are exceptionally low not exceeding 0.2 eV along the c-axis and correlating well with diffusion coefficients estimated using the DFT+U-NEB methodology and with the experimentally determined transport properties. These results suggest a new paradigm for the development of materials that support many monovalent ion reversible de/insertion processes in a single prototypical structural oxypolyanionic framework.
- Добавил в систему: Федотов Станислав Сергеевич