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 ℃, 1000 ℃ and 1300 ℃, the SiCN composites prepared at 1000 ℃ 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.