A high-performance Si oxide-coated graphite flake (SGF) composite anode for Li-ion batteries (LIBs) is synthesized using a microwave-assisted coating method. In this synthesis, a solution comprising liquid polysiloxanes is used as the Si-containing precursor. Heating the graphite flakes (GFs) with microwave induces the deposition of a Si-containing conformal layer on the GF surfaces, which is subsequently calcined to produce SGFs. When tested as a LIB anode, the resulting SGF exhibits a reversible specific capacity of nearly 480 mAh g−1, 97% capacity retention at a current density of 2.5 A g−1 (approximately 5 C-rate), and 94% capacity retention after 500 cycles with an average Coulombic efficiency > 99.9%. The results suggest new strategies for both designing and synthesizing high-performance anode materials for LIB applications.