Enhancing Ion Adsorption Capability through the Strong Interaction in Co<sub>9</sub>S<sub>8</sub>‐Carbon Hybrids Achieves Superior Sodium Ion Storage
Xinyi Ma, Xiaoyue He, Lai Yu, Nazir Ahmad, Zongzhi Tao, Zi Xuan Jiang, Jia Cheng Liang, Suyuan Zeng, Liang Shi, Genqiang Zhang
Abstract
Abstract Metal sulfides materials are promising anode candidates for Na + storage due to their low cost and high theoretical capacity, while the complex phase transition and inevitable volume expansion during cycling restrain their practical applications. Herein, a simple one‐pot manipulation strategy was designed to construct Co 9 S 8 nanoparticles strongly encapsulated in carbon nanotubes (Co 9 S 8 @C/NTs) composite structure with enhanced structural stability and reaction kinetics, resulting in greatly improved Na + storage performance. Specifically, the obtained Co 9 S 8 @C/NTs could exhibit a remarkable capacity of 500 mAh g −1 at 0.5 A g −1 after 100 cycles and exceptional cycling stability over 600 cycles with 88 % capacity retention at 1 A g −1 . Furthermore, the theoretical calculations combined with systematic characterizations confirm that the strong interaction between Co 9 S 8 and the carbon matrix could greatly enhance the Na + adsorption ability and facilitate the electron transfer dynamics for superior Na + storage capability. More importantly, the full cell device can deliver an outstanding energy density of 144.32 Wh kg −1 and a decent cycling life with 82 % capacity retention of almost 100 cycles at 0.1 A g −1 . This work could provide more valuable insights for designing advanced metal sulfide nanocomposites and demonstrate fascinating prospects for commercial application.