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

Abstract Silicon suboxide (SiO_x) 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 SiO_x severely hinder its practical applications. Herein, a unique necklace‐structured SiO_x‐based anode material consisting of carbon nanotube wired SiO_x/C@C spheres with a surface carbon coating layer (CNT@SiO_x/C@C) is constructed. The multiple carbon networks wire the whole composite anode material, effectively confining the volumetric variation of SiO_x, and enhancing the structural integrity of the electrode. The as‐synthesized necklace‐structured CNT@SiO_x/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 SiO_x. 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.