Synthesis and characterization of multi-layer core-shell structural LiFeBO3/C as a novel Li-battery cathode material

A multi-layer core-shell structural LiFeBO3/C has been successfully synthesized via spray-drying and carbothermal method using LiBO2·8H2O, Fe(NO3)3·9H2O, and citric acid as starting materials. The Rietveld refinement results indicate the sample consists of two phases: LiFeBO3 [94(6)% w/w], and LiFeO2 [6(4)% w/w]. SEM images show that the LiFeBO3 powders consist of rough similar-spherical particles with a size distribution ranging from 1 μm to 5 μm. TEM results present that the LiFeBO3 spherical particles are well coated by nano-carbon webs and form a multi-layer core-shell structure. The amount of carbon was determined to be 6.50% by C/S analysis. The prepared LiFeBO3-LiFeO2/C presents an initial discharge capacity of 196.5 mAh g−1 at the current density of 10 mA g−1 between 1.5 and 4.5 V, and it can deliver a discharge capacity of 136.1 mAh g−1 after 30 cycles, presents excellent electrochemical properties, indicating the surface sensitivity in the air was restrained.