Abstract
Aqueous sodium-ion batteries represent a promising approach for stationary energy storage; however, the lack of appropriate anode materials has substantially retarded their development. Herein, we demonstrated an iron-based phosphate material of Na3Fe3(PO4)4 as an inexpensive and efficacious anode alternative. While the Fe3+/Fe2+ redox couple renders a two-Na-insertion reaction with desirable potentials, its unique layered structure further facilitates the Na-insertion kinetics and reversibility. Consequently, this electrode exhibits an appealing Na-insertion performance, with a reversible capacity of ∼83 mAh g-1, suitable anode potential of -0.4 V vs Ag/AgCl, excellent rate capability of 200 C, and outstanding cycling of 6000 cycles. Utilizing operando synchrotron X-ray diffraction and X-ray absorption spectroscopy, we revealed the structural evolution of the Na3Fe3(PO4)4 anode during the two-electron reaction, where the extremely small volume expansion (∼3%) enables its fast-charging and long-cycling capability. Our work suggests new considerations of developing versatile iron phosphate compounds as appealing anode materials for energy storage in aqueous electrolytes.
Original language | English |
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Pages (from-to) | 63-71 |
Number of pages | 9 |
Journal | ACS Materials Au |
Volume | 2 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 12 2022 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2022 American Chemical Society.
ASJC Scopus Subject Areas
- Electronic, Optical and Magnetic Materials
- Biomaterials
- Polymers and Plastics
- Materials Chemistry
Keywords
- anode
- aqueous sodium ion batteries
- fast charging
- layered structure
- sodium iron phosphate