Lithium Storage Behavior of Expanded Microcrystalline Graphite/Fe₂O₃ Anode for Lithium-Ion Batteries

Abstract

Driven by the pressing need for improved performance of lithium-ion batteries in electric vehicles and portable electronics, this research aims to develop novel high-performance anode materials. Innovatively, expanded microcrystalline graphite (EMG) is used as the matrix material. Through a simple synthesis strategy, Fe₂O₃ nanoparticles are successfully introduced to prepare expanded microcrystalline EMG/Fe₂O₃ composites. The study systematically investigates the effects of different doping ratios on the electrochemical performance of the materials. The experimental results demonstrate that the EMG/Fe₂O₃-2 composite material exhibits the most excellent lithium storage performance: the initial discharge specific capacity is 1114.10 mAh·g^-1, and after 100 cycles, the discharge specific capacity remains at 1007.05 mAh·g^-1, with a capacity retention rate as high as 90.39%. The outstanding electrochemical performance is mainly attributed to the following factors. On the one hand, the porous structure of EMG not only provides an effective buffering space for the volume expansion of Fe₂O₃, but its complex conductive network also significantly enhances the charge transport efficiency of the composite material. On the other hand, the high theoretical specific capacity of Fe₂O₃ nanoparticles, combined with the EMG matrix, forms a synergistic effect that enhances the specific capacity of the composite material. This thesis not only elucidates the synergistic mechanism between EMG and Fe₂O₃ but also provides new strategies and perspectives for the performance breakthrough of lithium-ion battery anode materials.