Uniformly Dispersed Ultrasmall Fe(Co)Ni Alloy Nanoparticles Embedded in Thin‐Walled Carbon Nanotubes as High‐Performance Anode Materials for Lithium‐Ion Battery

Fe‐group nanoalloys are one of the most promising next‐generation anodes for lithium‐ion batteries (LIBs) due to their low cost, high capacity, excellent electrical conductivity, and lithium‐storage capability. However, the difficulties in constructing nanostructures and the tendency for alloy nanoparticles to agglomerate limit their practical application. Herein, a hybrid embedding structure with microporosity–mesoporosity is constructed by using thin‐walled carbon nanotubes (CNT) as the support. Within this structure, ultrasmall FeNi/CoNi alloy nanoparticles (10 nm) are uniformly embedded into the walls of thin‐walled CNTs (FNNT/CNNT). Benefit from this hybrid structure is that the agglomeration of FNNT/CNNT is effectively suppressed, leading to excellent cycling stability and high capacity (596.6 mA h g −1 for FNNT and 557.1 mA h g −1 for CNNT after 300 cycles at 1 A g −1 ) as anodes for LIBs. In the present method, a reference can be provided for the preparation of metal alloy/carbon nanocomposites.