Synthesis, characterization of core-shell carbon-coated CaSnO_3 nanotubes and their performance as anode of lithium ion battery

摘要

In this paper, we design a strategy to obtain core-shell carbon-coated CaSnO_3 nanotubes (hereafter C-CTO NTs) directly via a facile subsequent solvothermal synthesis using CaSn(OH)_6 nanotubes as precursor in a mixed ethanol and water solvent. The mixed solvent not only facilitates the phase transformation of CaSnO_3 from CaSn(OH)_6 to take place quickly, but also retains the tube-shaped morphology. The uniform decoration of C shell on the surface of CaSnO_3 nanotubes (hereafter CTO NTs) was confirmed by EELS (electron energy loss spectroscopy). Moreover we found that the uniform carbon-coating layer on the surface of CTO NTs played roles of a good conductor and a structure buffer to alleviate the strains from the volume variation of CTO NTs cores. So the core-shell structure possesses both the electroactivity of C and the advantages of nanotube structure. When used as an anode for Li ion battery, it shows enhanced cycling performance in term of cycling stability over bare CTO NT electrode and CaSnO_3 nanocube (hereafter CTO NC) electrode. To our best knowledge, this is the first attempt to use C-CTO NTs as an anode in Li ion battery.