Confining Mesoporous SiOx@C Spheres into 3D Ordered Macroporous Carbon as an Anode with Long-Cycling Performance for Lithium-Ion Batteries

Silicon suboxide (SiOx, 0 < x < 2) is a promising anode material for lithium-ion (Li-ion) batteries due to its high theoretical capacity, yet the application of SiOx anodes is limited by their low electrical conductivity and drastic volume expansion. Although integrating SiOx nanoparticles with carbon materials can mitigate these issues, achieving both uniform dispersion of SiOx nanoparticles within the carbon matrix and structural stability remains a significant challenge when using only conventional mechanical mixing, surface coating, and sol–gel methods. Herein, a combined sol–gel and soft-templating method is employed to encapsulate mesoporous SiOx@carbon (SiOx@C) spheres (m-SiOx@CS) within a three-dimensionally ordered macroporous carbon (3DOMC) framework, yielding a nanocomposite (3DOMC/m-SiOx@CS). In m-SiOx@CS, the uniformly dispersed SiOx nanoparticles and carbon provide abundant conductive interfaces to enhance reaction kinetics, and the mesoporous structure enables rapid mass transfer. Meanwhile, 3DOMC provides a stable skeleton to ensure the structural stability of the electrode during cycling. As a result, the 3DOMC/m-SiOx@CS electrode exhibits excellent electrochemical performance and cycling stability, maintaining a high reversible capacity of 488.1 mAh g–1 after 2000 cycles at 1 A g–1. Furthermore, the assembled 3DOMC/m-SiOx@CS||LiFePO4 Li-ion full batteries can maintain a high capacity of 82.5 mAh g–1 after 1000 cycles at 1 C. This study offers a broadly applicable structural design strategy for high-performance SiOx-based anodes.