Synergistic Application of Lithium Compensation and Graphene Technologies for High-Energy-Density Lithium-Ion Batteries

Abstract

Silicon-based anode materials are increasingly favored for lithium-ion batteries (LIBs) due to their exceptionally high specific capacity. However, overcoming the mechanical and electrical challenges associated with Si-based anodes during cycling, particularly under high electrode loading conditions, requires a delicate balance between the electrode components and their microstructural design. In this study, we propose that the targeted integration of graphene (Gr) is key to engineering highly expandable Si suboxide (SiOx)-based anodes. Gr is precisely positioned on the surface of SiOx particles and within the pores of the SiOx-graphite electrode. This dual positioning allows Gr to function as both a mechanical buffer and electrical interconnector, effectively mitigating microstructural deformation and ensuring stable cycling performance. As a result, the SiOx-graphite anode, with a high areal capacity of 5.9 mAh cm-2, demonstrates remarkable capacity retention of over 81.9% after 150 cycles in full cells. Additionally, paired with a high-capacity cathode, it achieves an impressive anode volumetric energy density of 790 mAh cm-3, showcasing its potential for advanced lithium-ion batteries.