Promoting the electrochemical properties of yolk-shell-structured CeO2 composites for lithium-ion batteries

Lithium-ion batteries offer significant convenience to modern portable technology and our daily lives due to their high energy density and cycling capabilities. Cerium oxides are attracting significant attention as Li-ion battery anode materials due to their nontoxicity and fast redox kinetics. However, these anodes face critical issues, such as poor electronic conductivity and serve volume expansion upon Li-ion intercalation. Herein, yolk-shell-structured CeO2 encapsulated in mesoporous carbon nanospheres (CeO2@void@C) is proposed with an adjustable void between the CeO2 core and the outer carbon layer. A significantly enhanced capacity and rate performance are obtained for the target CeO2@void@C when compared with the untreated CeO2 anode. The reversible capacity of CeO2@void@C is double that of the untreated CeO2 anode. Additionally, the yolk-shell-structured CeO2 shows a slow capacity decay and maintains a capacity of 210 mAh·g at a current density of 1000 mA·g with a ~100% Coulombic efficiency even after 1000 cycles. This improvement originates from the conductivity of the coating carbon layer and the void that constrains the volume change upon electrochemical lithiation/delithiation. Page 2 of Shi et al. Microstructures 2021;1:2021005 https://dx.doi.org/10.20517/microstructures.2021.04 14