Rational Synthesis of Spongy Fe₃N@N-Doped Carbon Nanorods with Controlled Topography and Porosity for Enhanced Energy...

Iron nitrides with the merits of high theoretical capacities, cost-effectiveness, and good electronic/ionic conductivity have been recognized as attractive anode candidates for lithium-ion batteries (LIBs). Carbon compositing, pore engineering, and nanostructure construction have proved to be effective strategies to prepare high-performance metal nitride anodes for LIBs. Herein, we synthesized a series of Fe₃N-embedded and N-doped carbon nanorods (Fe₃N@NCNR) with a hierarchical porous system and controllable topography by metal-catalyzed graphitization-nitridization of the Fe(III)-triazole framework (Fe-MOF) and thermal evaporation of the triblock copolymer F127 template assembled in Fe-MOF via hydrogen bonding interaction, followed by the air oxidation and urea-assisted ammonolysis processes. The Fe₃N@NCNR as anodes for LIBs display extraordinary lithium storage capabilities with a high reversible capacity of 830 mA h g^-1 at 0.1 C, a good rate performance of 576 mAh g^-1 at 5 C, and a long-term cycling stability of 742 mA h g^-1 over 600 cycles at 1 C. Such outstanding performance benefits from the spongy carbon nanorods with rich macropores for rapid electronic/ionic transport and effective accommodation of electrode volume expansion, abundant N-doped meso-/microporous carbon for the additional storage of Li⁺ via capacitive effect, and the efficient utilization of Fe₃N nanoparticles uniformly distributed through carbon nanorods. Importantly, this work introduces an effective strategy to construct superior performance nitride anodes from MOF surfactants based on hydrogen bonding-driven interface self-assembly and provides insight into the preparation of highly efficient nanoarchitectures for Li⁺ storage.