Zhang Jiexin, Zhou Xi, Wang Yunxiao, Qian Jiangfeng, Zhong Faping, Feng Xiangming, Chen Weihua, Ai Xinping, Yang Hanxi, Cao Yuliang
College of Chemistry and Molecular Sciences, Hubei International Scientific and Technological Cooperation Base of Sustainable Resource and Energy, Wuhan University, Wuhan, 430072, China.
National Engineering Research Center of Advanced Energy Storage Materials, Changsha, 410205, China.
Small. 2019 Nov;15(46):e1903723. doi: 10.1002/smll.201903723. Epub 2019 Oct 2.
As promising cathode materials, iron-based phosphate compounds have attracted wide attention for sodium-ion batteries due to their low cost and safety. Among them, sodium iron fluorophosphate (Na FePO F) is widely noted due to its layered structure and high operating voltage compared with NaFePO . Here, a mesoporous Na FePO F@C (M-NFPF@C) composite derived from mesoporous FePO is synthesized through a facile ball-milling combined calcination method. Benefiting from the mesoporous structure and highly conductive carbon, the M-NFPF@C material exhibits a high reversible capacity of 114 mAh g at 0.1 C, excellent rate capability (42 mAh g at 10 C), and good cycling performance (55% retention after 600 cycles at 5 C). The high plateau capacity obtained (>90% of total capacity) not only shows high electrochemical reversibility of the as-prepared M-NFPF@C but also provides high energy density, which mainly originates from its mesoporous structure derived from the mesoporous FePO precursor. The M-NFPF@C serves as a promising cathode material with high performance and low cost for sodium-ion batteries.
作为有前景的阴极材料，铁基磷酸盐化合物因其低成本和安全性而在钠离子电池领域引起了广泛关注。其中，氟磷酸钠铁（NaFePO₄F）因其层状结构和与NaFePO₄相比更高的工作电压而备受关注。在此，通过简便的球磨结合煅烧方法合成了一种由介孔FePO₄衍生的介孔NaFePO₄F@C（M-NFPF@C）复合材料。受益于介孔结构和高导电性碳，M-NFPF@C材料在0.1C时表现出114 mAh g⁻¹的高可逆容量、优异的倍率性能（10C时为42 mAh g⁻¹）和良好的循环性能（5C下600次循环后保持率为55%）。获得的高平台容量（>总容量的90%）不仅表明所制备的M-NFPF@C具有高电化学可逆性，还提供了高能量密度，这主要源于其由介孔FePO₄前驱体衍生的介孔结构。M-NFPF@C作为一种高性能、低成本的钠离子电池阴极材料具有广阔前景。
