Highly Stable Silicon-Carbon-Nitrogen Composite Anodes from Silsesquiazane for Rechargeable Lithium-Ion Battery

Herein, we developed novel silicon-carbon-nitrogen (SiCN) composites synthesized by pyrolyzing silsesquiazane polymer as an anode material for rechargeable lithium-ion batteries. Among variable pyrolysis temperatures of 700 °C, 1000 °C and 1300 °C, the SiCN composites prepared at 1000 °C showed the highest capacity with outstanding battery cycle life by cyclic voltammetry and electrochemical impedance spectroscopy. Such good battery and electrochemical performances should be attributed to a proper ratio of carbon and nitrogen or oxygen in the SiCN composites. Furthermore, our SiCN electrode possessed better lithium ion conductivity than pure silicon nanoparticles. This work demonstrates that polymer-derived composites are among the promising strategies to achieve highly stable silicon anodes for rechargeable batteries.