Domain-limited growth strategy to construct Fe3C@C@CNTs heterogeneous interfaces for multi-functional high-performance lithium-ion storage and microwave absorption

Abstract

Rational designed cost-effective material is significant in the field of electric energy storage and microwave absorber. In this work, carbon coated Fe3C nanoparticles (NPs) encapsulated carbon nanotubes (Fe3C@C@CNTs) is delicately constructed through in-situ chemical vapor deposition (CVD) strategy. As a promising anode material for lithium-ion batteries (LIBs), the Fe3C@C@CNTs nanocomposite facilitates electron transport with intensive interfacial interaction, making it an ideal prototype to thoroughly understand the mechanisms of interatomic charge transfer mechanism. As a result, this well-designed Fe3C@C@CNTs anode exhibits a high reversible capacity of 1027 mAh g−1 after 150 cycles at 0.1 A g−1 and excellent cycling stability with 71 % capacity retention at 519 mAh g−1 after 1000 cycles at 1.0 A g−1. Electrochemical kinetic results confirm that the pseudocapacitance contributions reach up to 90.1 % at 1.0 mV s−1, and the higher pseudocapacitance characteristic is ascribed to the multi-dimensional encapsulated by CNT layer and carbon layer. Meanwhile, depending on the peculiar cavity structure and heterogeneous interfaces effects constructed by multi-dimensional encapsulated structure, the minimum reflection loss (RLmin) of Fe3C@C@CNTs nanocomposite can reach up to −67.63 dB in effective absorption bandwidth (EAB) of 7.12 GHz with the optimal matching thickness of 2.28 mm, suggesting its extensive potential application as practical alternative absorber. This domain-limited growth strategy opens a new horizon to achieve multi-functional application and beyond for Fe-based nanomaterial.