Achieving High-Performance SiO Anode via Synergy of In Situ Generated Cu₃Si Nanobeads and N-Doped Carbon Coating

Silicon monoxide (SiO) has emerged as a promising candidate for next-generation lithium-ion batteries (LIBs), owing to its ultrahigh theoretical capacity, abundant reserves, and moderate lithiation potential. However, SiO anodes still face challenges, including significant volume expansion, insufficient electronic conductivity, and poor lithium-ion diffusion kinetics. To address these challenges, the SiO-Cu₃Si@NC material was synthesized through a facile two-step method of iodine-initiated pyrrole (Py) polymerization and carbothermal reduction, during which highly conductive Cu₃Si nanobeads were generated in situ at the SiO/carbon interface. Multiple characterizations and electrochemical measurements indicate that the PPy-derived N-doped carbon coating and Cu₃Si nanobeads not only synergistically buffer the volume expansion of the SiO anode but also enhance the electronic conductivity and Li⁺ diffusion kinetics of the electrode. As a result, the SiO-Cu₃Si@NC anode exhibits exceptional cycling stability (89.5% over 400 cycles at 1.0 A g^-1) and superior rate performance (647.7 mAh g^-1 at 5.0 A g^-1). Furthermore, the full cell paired with the commercial LiFePO₄ cathode demonstrates high cycling stability, maintaining 89.2% capacity retention over 150 cycles at 1 C, demonstrating its practical applicability. This work proposes a straightforward yet effective strategy to enhance the electrochemical performance of SiO anodes, advancing the development of high-energy density LIBs.