Amorphous Sb/C composite with isotropic expansion property as an ultra‐stable and high‐rate anode for lithium‐ion batteries
Zezhou Yang, Chengyi Zhang, Yuqing Ou, Zhihao Su, Yan Zhao, Hengjiang Cong, Xinping Ai, Jiangfeng Qian
Abstract
Abstract Antimony (Sb) is an intriguing anode material for Li‐ion batteries (LIBs) owing to its high theoretical capacity of 660 mAh·g −1 and appropriate working potential of ~ 0.8 V (vs. Li + /Li). However, just like all alloying materials, the Sb anode suffers from huge volume expansion (230%) during repeated insertion/extraction of Li + ions, resulting in structural deterioration and rapid capacity decay. In this work, a novel amorphous Sb/C composite with atomically dispersed Sb particles in carbon matrix is prepared via a straightforward high‐energy ball milling approach. The intimate intermixing of amorphous Sb with C provides homogeneous element distribution and isotropic volume expansion during cycling, resulting in persistent structural stability. Meanwhile, the disordered structure of amorphous material shortens the diffusion distance of lithium ions/electrons, promoting fast reaction kinetics and rate capability. Benefiting from the aforementioned effects, the amorphous Sb/C exhibits a high reversible capacity of 537.4 mAh·g −1 at 0.1 A·g −1 and retains 201.0 mAh·g −1 at an ultrahigh current rate of 10.0 A·g −1 . Even after 1500 deep cycles at 2.0 A·g −1 , the amorphous Sb/C electrode still maintains 86.3% of its initial capacity, which outperforms all existing Sb‐based anodes reported so far. Post‐mortem analysis further reveals a greatly reduced volume variation of merely 34.6% for the amorphous Sb/C electrode, much lower than that of 223.1% for crystalline Sb materials. This study presents a new approach to stabilizing Sb‐based alloy anodes and contributes to the construction of high‐performance amorphous anode materials for LIBs, enabling advanced energy storage.