Structurally Reinforced Silicon/Graphene Composite for Lithium-Ion Battery Anodes: Carbon Anchor as a Conductive Structural Support.

Herein, a Si/reduced graphene oxide (rGO)/C microsphere composite is reported, wherein sucrose-derived carbon binds Si nanoparticles (NPs) and rGO to act as a carbon anchor and links neighboring rGO sheets to reinforce the composite structure. In this structurally reinforced Si/rGO/C composite, the electron conduction pathways between rGO and Si NPs were maintained even under large volume changes during repeated charge-discharge processes. Consequently, the Si/rGO/C composite anode exhibited an initial discharge capacity of 1209 mAh g and superior cyclability (92 % retention at 100 cycles), initial coulombic efficiency of 80.5 %, and high-rate capability even at a high C rate (6 C). Furthermore, the change in anode thickness after repeated cycling was negligible, confirming the structural stability imparted by the sucrose-derived carbon binder. A full cell assembled with a LiCoO cathode and the Si/rGO/C composite anode remained stable over 200 cycles.