Spatially confined FeF3 cathodes in N-doped carbon nanotubes for lithium storage

Herein, a N-doped carbon nanotube encapsulated FeF₃ nanoparticle (FeF₃@N-CNTs) composite was developed via in situ pyrolysis and gas-phase fluorination strategies. The 3D carbon constrained scaffold enhances conversion reaction kinetics and effectively suppresses significant volume changes in the FeF₃ cathode during cycling. Consequently, FeF₃@N-CNTs exhibits excellent rate capability and maintains a high discharge capacity of 110.6 mA h g^-1 after 5000 cycles at 2 A g^-1. It is believed that this study presents an innovative strategy for the development of long-cycling conversion-type cathode materials.