Confined self-assembly of SiOC nanospheres in graphene film to achieve cycle stability of lithium ion batteries

Abstract

SiOC nanoparticles are proposed as one of the most promising anodes for Li-ion batteries due to the afforded high capacity and outstanding cycling stability. However, the side reactions caused by the high specific surface area and high inter-particle resistance hinder the practical application of SiOC materials. Herein, a confined self-assembly process has been developed to encapsulate boron doped SiOC (B-SiOC) nanospheres into a conductive graphene film (B-SiOC@G). The B doping could induce the interconnected assembly of SiOC nanoparticles, while the graphene as a conductive framework can buffer volume change and facilitate Li-ion and electron transport. Therefore, the resulting B-SiOC@G anode shows excellent cycle stability with a 0.03% decay per cycle at 0.5 A g⁻¹ and maintains a reversible capacity of 445 mA h g⁻¹ after 1000 cycles. These results suggest that B-SiOC@G is a promising anode material for highly stable lithium ion batteries.