材料科学
异质结
阴极
四方晶系
化学工程
氟化物
能量转换效率
光电子学
无机化学
物理化学
晶体结构
结晶学
化学
工程类
作者
Chuanzhong Lai,Keyi Chen,Meng Lei,Jiulin Hu,Shuangqiang Chen,Chilin Li
标识
DOI:10.1002/adfm.202312415
摘要
Abstract Conversion‐reaction metal fluoride cathodes have the advantages of low cost, environmental friendliness, and high energy density. However, their tailored synthesis and structure design under safe, facile, and scalable conditions have always been a puzzle, which limits the popularization of conversion‐type cathodes in lithium metal batteries. To address these challenges, here an iron fluoride heterostructure with FeF 2 and FeF 3 binary phases is proposed and prepared by deep eutectic solvent method under the assistance of cobalt cation as an oxidization promoter. The compact heterogeneous contact between tetragonal FeF 2 and hexagonal tungsten bronze FeF 3 phases enables the promotion and stabilization of interface charge transfer and topotactic conversion reaction. The narrower band gap of FeF 2 , higher theoretical capacity and thermodynamic potential of FeF 3 synergistically contribute to the balance between cycling reversibility and capacity. The heterostructure cathode with an optimized molar ratio of FeF 2 /FeF 3 can realize a highly reversible capacity of ≈520 mAh g −1 in the first tens of cycles and 305 mAh g −1 after 200 cycles. The typical two‐stage reaction plateaus are well preserved even under the high current density of 1000 mA g −1 . The green synthesis strategy and heterostructure fluoride design open a new horizon for the development of high‐energy‐density metal fluoride batteries.
科研通智能强力驱动
Strongly Powered by AbleSci AI