SiOx Encapsulated in Graphene Bubble Film: An Ultrastable Li‐Ion Battery Anode

: SiOx is proposed as one of the most promising anodes for Li-ion batteries (LIBs) for its advantageous capacity and stable Li uptake/release electrochemistry, yet its practical application is still a big challenge. Here encapsulation of SiOx nanoparticles into conductive graphene bubble film via a facile and scalable self-assembly in solution is shown. The SiOx nanoparticles are closely wrapped in multilayered graphene to reconstruct a flake-graphite-like macrostructure, which promises uniform and agglomeration-free distribution of SiOx in the carbon while ensures a high mechanical strength and a high tap density of the composite. The composites present unprecedented cycling stability and excellent rate capabilities upon Li storage, rendering an opportunity for its anode use in the next-generation high-energy LIBs.