Regulating structural units and morphology of SiOC anode for enhanced high-rate storage and long-life lithium ion batteries

The widespread use of silicon oxycarbide (SiOC) anodes in industry has been hampered by their limited reversible capacity, subpar rate performance, and complex manufacturing methods. In this research, a novel strategy is proposed to in situ construct SiOC with oxygen-rich structural units and flake morphology via one-pot synthesis, which integratively facilitates the reversible capacity and enhances the transport capability of Li + . Benefiting from these structural and compositional merits, the produced SiOC electrode showcases an impressive reversible capacity of 906 mAh g −1 at 0.1 A g −1 , a remarkable rate capability of 591 mAh g −1 and cycling stability of 98 % capacity retention rate at 2.0 A g −1 after 1200 cycles. Characterization results prove that the SiOC with a higher content of oxygen-rich structural units and flakes is helpful in forming the stable solid-electrolyte interface film and buffering volume expansion. Furthermore, it is demonstrated that the SiOC anodes containing Li x SiO y compounds reduce the irreversible use of Li-ions during the initial reaction. Our findings present an effective method to simultaneously manipulate the structural units and morphology of SiOC compounds, paving the way for superior electrochemical performance.