Liu Shuangxu, Chen Jingzhao, Su Yong, Zheng Chuanzuo, Zhu Dingding, Zhang Xuedong, Zhou Xiang, Ouyang Ren, Huang Quanwei, He Yunfei, Tang Liang, Li Shuai, Qiu Yuan, Wang Gang, Tang Yongfu, Zhang Liqiang, Huang Qiao, Huang Jianyu
School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan, 411105, P. R. China.
Clean Nano Energy Center, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, 066004, P. R. China.
Small. 2022 Jul;18(28):e2202006. doi: 10.1002/smll.202202006. Epub 2022 Jun 10.
Conversion-type cathodes such as metal fluorides, especially FeF and FeF , are potential candidates to replace intercalation cathodes for the next generation of lithium ion batteries. However, the application of iron fluorides is impeded by their poor electronic conductivity, iron/fluorine dissolution, and unstable cathode electrolyte interfaces (CEIs). A facile route to fabricate a mechanical strong electrode with hierarchical electron pathways for FeF nanoparticles is reported here. The FeF /Li cell demonstrates remarkable cycle performances with a capacity of 300 mAh g after a record long 4500 cycles at 1C. Meanwhile, a record stable high area capacity of over 6 mAh cm is achieved. Furthermore, ultra-high rate capabilities at 20C and 6C for electrodes with low and high mass loading, respectively, are attained. Advanced electron microscopy reveals the formation of stable CEIs. The results demonstrate that the construction of viable electronic connections and favorable CEIs are the key to boost the electrochemical performances of FeF cathode.
诸如金属氟化物，特别是氟化铁（FeF）和氟化亚铁（FeF ）等转换型阴极，是下一代锂离子电池中替代嵌入型阴极的潜在候选材料。然而，氟化铁的应用受到其电子导电性差、铁/氟溶解以及不稳定的阴极电解质界面（CEI）的阻碍。本文报道了一种制备具有分级电子通路的机械强度高的氟化铁纳米颗粒电极的简便方法。FeF/Li电池在1C下经过创纪录的4500次循环后，展现出显著的循环性能，容量为300 mAh g。同时，实现了超过6 mAh cm的创纪录稳定高面积容量。此外，分别在20C和6C下，对于低质量负载和高质量负载的电极，还获得了超高倍率性能。先进的电子显微镜揭示了稳定CEI的形成。结果表明，构建可行的电子连接和良好的CEI是提高FeF阴极电化学性能的关键。
