Core–shell CeO2@C nanospheres as enhanced anode materials for lithium ion batteries

Abstract

In this work, novel CeCO₃OH@C nanocomposites were prepared via a one-pot approach by hydrothermal carbonization of a solution of glucose as a carbon precursor in the presence of Ce(NO₃)₃·6H₂O and urea. It was found that glucose not only facilitates the formation of CeCO₃OH nanoparticles, but also leads to a uniform, glucose-derived, carbon-rich polysaccharide (GCP) overlayer on the CeCO₃OH nanocomposites. By adjusting the concentrations of glucose, the morphology of the samples was transformed from spindle nanoparticles to uniform spherical particles. CeO₂@C with a core–shell structure was fabricated after calcining the CeCO₃OH@C nanospheres under an N₂ atmosphere. The obtained products were characterized by SEM, TEM, XRD, TG-DSC, FT-IR and charge–discharge test. The electrochemical performance test showed that these CeO₂@C core–shell spheres as an anode material for lithium ion batteries exhibited an initial discharge specific capacity of 863.0 mA h g⁻¹ in the potential range of 3.0–0.0 V. After 50 cycles, the capacity of the CeO₂@C core–shell spheres was stabilized reversibly at about 355.0 mA h g⁻¹. The improved cycling performance was attributed to the carbon shells, which can enhance the conductivity of the CeO₂ core and suppress the aggregation of active particles during cycling. These CeO₂@C core–shell spheres are promising anode materials for lithium ion batteries.