1. Rapid mechanochemical synthesis of high-performance Na 4 Fe 2.94 Al 0.04 (PO 4 ) 2 (P 2 O 7 )/C cathode material for sodium-ion storage.
- Author
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Wang Y, Fei W, Zhang X, Deng M, Lu S, Zhang J, Rao K, Yuan Y, Sui Y, and Wu L
- Abstract
Na
4 Fe3 (PO4 )2 (P2 O7 ) is regarded as a promising cathode material for sodium-ion batteries due to its affordability, non-toxic nature, and excellent structural stability. However, its electrochemical performance is hampered by its poor electronic conductivity. Meanwhile, most of the previous studies utilized spray-drying and sol-gel methods to synthesize Na4 Fe3 (PO4 )2 (P2 O7 ), and the large-scale synthesis of the cathode material is still challenging. This study presents a composite cathode material, Na4 Fe2.94 Al0.04 (PO4 )2 (P2 O7 )/C, prepared via a straightforward ball-milling technique. By substituting Al3+ minimally into the Fe2+ site of NFPP, Fe defects are introduced into the structure, hindering the formation of NaFePO4 and thereby enhancing Na-ion diffusion kinetics and conductivity. Additionally, the average length of AlO bonds (2.18 Å) is slightly smaller than that of FeO bonds (2.19 Å), contributing to the superior structural stability. The smaller ionic radii of Al3+ induce lattice contraction, further enhancing the structural stability. Moreover, the surface of material particles is coated with a thin layer of carbon, ensuring excellent electrical conductivity and outstanding structure stability. As a result, the Na4 Fe2.94 Al0.04 (PO4 )2 (P2 O7 )/C cathode exhibits excellent electrochemical performance, leading to high discharge capacity (128.1 mAh g-1 at 0.2 C), outstanding rate performance (98.1 mAh g-1 at 10 C), and long cycle stability (83.7 % capacity retention after 3000 cycles at 10 C). This study demonstrates a low-cost, ultra-stable, and high-rate cathode material prepared by simple mechanical activation for sodium-ion batteries which has application prospects for large-scale production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)- Published
- 2024
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