Silicon nanoparticles encapsulated in multifunctional crosslinked nano-silica/carbon hybrid matrix as a high-performance anode for Li-ion batteries

The application of silicon as anode materials for lithium-ion batteries is limited by the huge volumetric expansion and complex synthesis processes. Herein, silicon nanoparticles encapsulated in multifunctional crosslinked nanosilica/carbon hybrid matrix (Si@n-SiO2/C) composites are successfully synthesized via simultaneous condensation copolymerization between (3-aminopropyl)-triethoxysilane (APTES) and L-ascorbic acid (L-AA). With the introduction of nano-silica, the multifunctional nano-silica/carbon hybrid matrix can significantly maintain structural integrity during the volume change of silicon, provide a higher capacity than the traditional single carbon coating layer and enhance the conductivity of the materials. Correspondingly, the obtained Si-2@n-SiO2/ C composites display quite outstanding cycle stability and superior structural integrity maintenance, which delivers a capacity of 800.7 mAh g-1 after 300 cycles at the current density of 1 A g-1. Such a novel coating layer structure design and simultaneous growth of nano-silica/carbon hybrid matrix layer on silicon nanoparticles will provide a simple synthesis strategy for manufacturing high-performance Si-based anode materials.

Automated summary

Encapsulating silicon nanoparticles in a multifunctional nanosilica/carbon hybrid matrix can significantly improve structural integrity, capacity, and conductivity, resulting in outstanding cycle stability and structural integrity maintenance for Si-2@n-SiO2/C composites.