Amorphous SiO₂ Nanoparticles Encapsulating a SiO Anode with Strong Structure for High-Rate Lithium-Ion Batteries

Constructing a robust structure is crucial for addressing the inherent flaws of SiO-based anode materials, such as significant volume expansion and high ion and electron resistance. Therefore, in this article, we synthesized a SiO-based composite denoted as SiO-SiO2@C via a facile liquid-phase method. This composite possessed a sturdy three-dimensional structure and dual functionality. The superstructure was formed by the carbon-coated amorphous SiO2 nanoparticles surrounding the SiO particles, which endowed the structural stability of SiO-SiO2@C. It is worth noting that the SiO-SiO2@C composite manifested a high ICE of 75.7% and an impressive reversible capacity of 1061.0 mA h g(-1) at 0.2 A g(-1) after 100 cycles, with a 97% capacity retention compared to the second discharge. Furthermore, this electrode showed exceptional cycle performance of 430.5 mA h g(-1) after 700 cycles at 2 A g(-1) and rate performance with an average reversible capacity of 703.4 mA h g(-1) at 3 A g(-1). Overall, the prepared SiO-SiO2@C electrode material displayed a huge opportunity for lithium-ion battery anodes.