Improvement effect of Co and Ce oxides on the properties of CeO2-Co2O3-Fe2O3 anode materials

Abstract

Lithium-ion batteries offer several advantages, including high specific energy, extended lifespan, portability, and environmental friendliness. Transition metal oxides are attractive candidates for negative electrode materials due to their higher theoretical specific capacity. To address issues related to poor stability and volume expansion, cobalt trioxide and cerium oxide were introduced as dopants in iron oxide. This study involved the preparation of Co2O3-Fe2O3 and CeO2-Co2O3-Fe2O3 composites, followed by structural characterization and investigation of their electrochemical properties. The doping of cobalt and cerium oxide proved advantageous in refining particle size. Notably, 1% Co2O3-Fe2O3 particles displayed uniform sizing and tight binding. Additionally, the sample containing 0.05% CeO2 exhibited the smallest particle size and a more homogeneous distribution. Furthermore, cobalt and cerium oxide doping significantly improved electrochemical stability. The discharge capacity of 1% Co2O3-Fe2O3 and 0.05% CeO2-1% Co2O3-Fe2O3 after undergoing 100 constant-current charge and discharge cycle respectively remained at 553.17 mAh/g, 698.57 mAh/g. As a negative electrode material in lithium-ion batteries, the composite oxide 0.05% CeO2-1% Co2O3-Fe2O3 demonstrated superior reversibility and stability during the process of lithium-ion insertion and removal, while also exhibiting low contact resistance and charge transfer resistance.