MOF-derived Al-doped Na2FePO4F/mesoporous carbon nanonetwork composites as high-performance cathode material for sodium-ion batteries. (20th March 2021)

• Record Type: Journal Article
• Authors: Li, Haiming; Wang, Tailin; Wang, Xue; Li, Guangda; Shen, Jianxing; Chai, Jinling
• Is Part Of: Electrochimica acta. Volume 373(2021)
• Publication Date: 2021-03-20
• Subjects: Na2FePO4F -- Metal–organic frameworks -- Mesoporous carbon nanonetwork -- Metal doping -- Sodium-ion batteries; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2021.137905
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: MOF-derived mesoporous carbon-coated and Al-doped co-modified Na2 FePO4 F cathode materials were successfully prepared by a simple solid-state reaction method. The conductivity considerably improved after coating with MOF-derived mesoporous carbon nanonetwork coating and doping with Al. Al-doped Na2 FePO4 F/MOF-C composites show substantial improvements on electrochemical performance in terms of rate capability and cycle performance. Abstract: An Al-doped Na2 FePO4 F/mesoporous carbon nanonetwork derived from an metal–organic framework (MOF) material, was synthesized using a simple solid-state reaction method and evaluated as a promising cathode material for sodium-ion batteries. The MIL-53(Al) derived mesoporous carbon nanonetwork coating can enhance electron conductivity in Na2 FePO4 F cathode materials. The doping derived from MIL-53(Al) caused no damage to the crystal structure of the material, and Fe 2+ site was replaced by Al 3+ successfully. Therefore, the Al-doped Na2 FePO4 F/MOF-C composites exhibit substantial improvements in electrochemical performance in terms of rate capability and cycle performance. When current density increased from 0.1 C to 5 C, the specific capacity of Na1.94 Fe0.94 Al0.06 PO4 F/MOF-C only decreased from 115.2 mAh g −1 to 63.2 mAh g −1 ; thus, the composite presented outstanding rate capability. Moreover, an excellent capacity retention of 70.3% was maintained from the initial value of 70.4 mAh g −1 to 49.5 mAh g −1 after the 500th cycle at 5 C. This study provides insights into designing high-performance cathode materials by improving structural stability and the electrical conductivity induced by MOF-derived carbon coating and metal doping. Graphical abstract: MOF-derived mesoporous carbon-coated and Al-doped co-modified Na2 FePO4 F cathode materials were successfully prepared by a simple solid-state reaction method. The conductivity of the Na2 FePO4 F considerably improved after coating with MOF-derived mesoporous carbon nanonetwork and doping with Al; hence, the rate and cycle performances of the material dramatically improved. Image, graphical abstract