Rational design of dual-functional core-shell SiO_x/C@MoO₂ with hierarchical structure for enhanced lithium storage

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Silicon oxide (SiO_x) is a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity and low cost.
• However, its practical application is limited by poor electrical conductivity and significant volume changes during cycling.

Purpose of the Study:

• To develop a novel SiO_x/C@MoO₂ composite with a dual-functional core-shell structure to overcome the limitations of SiO_x anodes.
• To improve the electrochemical performance and cycling stability of LIBs.

Main Methods:

• Fabrication of the SiO_x/C@MoO₂ composite using spray drying and carbonization techniques.
• Characterization of the material's structure and electrochemical properties.

Main Results:

• The composite features an asphalt-derived carbon coating for conductivity and MoO₂ nanoparticles for active sites and volume buffering.
• The SiO_x/C@MoO₂ anode achieved a high initial Coulombic efficiency (ICE) of 76.8% and maintained a stable capacity of 508 mAh g^-1 after 1000 cycles at 1.0 A g^-1.
• A full cell using SiO_x/C@MoO₂ demonstrated 63.8% capacity retention after 100 cycles.

Conclusions:

• The core-shell SiO_x/C@MoO₂ composite effectively enhances the performance of silicon-based anodes for LIBs.
• The synergistic effects of the carbon framework and MoO₂ nanoparticles contribute to improved conductivity, volume stability, and a stable solid electrolyte interphase (SEI) film.
• This design offers a new strategy for developing advanced anode materials for high-performance energy storage devices.