Necklace‐Structured Silicon Suboxide‐Based Anode Materials with Multiple Carbon Networks for Stable Lithium Storage

Abstract

AbstractSilicon suboxide (SiOx) attracts great attentions from both academy and industry owing to its higher capacity than graphite and smaller volume swelling than Si, making it possible to achieve a tradeoff between capacity and cycling stability. Whereas, the volume expansion problem and poor electrical conductivity of SiOx severely hinder its practical applications. Herein, a unique necklace‐structured SiOx‐based anode material consisting of carbon nanotube wired SiOx/C@C spheres with a surface carbon coating layer (CNT@SiOx/C@C) is constructed. The multiple carbon networks wire the whole composite anode material, effectively confining the volumetric variation of SiOx, and enhancing the structural integrity of the electrode. The as‐synthesized necklace‐structured CNT@SiOx/C@C manifests decent lithium storage behaviors in terms of discharge capacity (857.7 mAh g−1 at 0.1 A g−1), cyclability (81.7% capacity retention over 100 cycles at 0.1 A g−1), and rate capability (333.3 mAh g−1 at 10 A g−1). This study demonstrates the effectiveness of constructing multiple carbon networks for tackling the volume swelling and conductivity issues of SiOx. It is also anticipated that this structural design would be generally applied to other high‐capacity electrode materials suffering from large volume fluctuation and low conductivity.