Multifunctional core-shell CaSnO3@N-doped carbon coaxial nanocables with excellent lithium storage performance and efficient microwave absorption

It is highly desirable but challenging to design multi-functional materials for energy storage and electromagnetic (EM) wave absorption. Herein, core-shell CaSnO3@N-doped carbon (CSO@NCNFs) coaxial nanocables with a one-dimensional (1D) architecture have been synthesized by the electrospinning method combined with in-situ polymerization and heat treatment. In the resulting placement, the CaSnO3 nanofibers (CSONFs) core with an average diameter of 52.5 nm is confined in the high electronic conductivity of the N-doped carbon sheaths with a thickness ranging from 27.3 to 67.2 nm. The lithium storage performance of the CSO@NCNFs nanocable electrode is much higher than that of the CSONFs electrode, due to (i) a large number of void spaces and active sites generated by the structure of the 1D core-shell nanocables, (ii) a fast transport network constructed by carbon sheaths prominently enhances the transport of both electrons and lithium ions, and (iii) the structural stability achieved through the buffering mechanism created by the CaSnO3@NCNFs coaxial construction. On the other hand, the ingenious structural design, multiple heterogeneous interfaces and multi-component strategy give rise to a synergistic mechanism of the impedance match condition, conductive dissipation, polarization dissipation and multiple reflection/scattering. The coaxial nanocables display good microwave absorption (MA) properties, featuring a reflection loss (RL) value of –47.0 dB at 8.2 GHz and 2.5 mm, and an effective absorption bandwidth (EAB) of 4.7 GHz at 1.4 mm. This unique structural design is believed to provide a reference for the preparation of multi-functional materials.