Optimized Heterostructures by Preferred Crystal Orientation for Ultrafast Sodium Storage
Man Zhang, Shunchao Wang, Jingchuan Zhu, Fenghua Zheng, Yongjie Jiang, Sijiang Hu, Yahao Li, Youguo Huang, Qichang Pan, Hongqiang Wang, Xing Ou, Qingyu Li
Abstract
Abstract Accelerating the Na + diffusion kinetics and enhancing the structural stability in sulfide‐based anodes by structural engineering is an extremely effective strategy for improving sodium storage performance. Herein, an optimized Co 9 S 8 /MoS 2 heterojunction with preferred crystal orientation is delicately designed and successfully fabricated. Distinguish from the conventional heterostructure with anisotropic distribution, the preferred crystal orientation with isotropic structure can provide a rapid Na + ‐diffusion pathway and regulate Na + ‐concentration to promote its uniform distribution. Furthermore, it simultaneously realizes the even dispersion of inner stress and acquire the structural stability during the discharge/charge processes. Additionally, the abundant heterointerfaces with one direction effectively improve the charge transfer and reduce the Na + ‐diffusion distance, ensuring the boosted reaction kinetic. As expected, ascribing to the synergetic effect, the Co 9 S 8 /MoS 2 presents excellent ultra‐high rate performance and long‐term cycling stability for sodium ion batteries. Specifically, a high capacity of 492.1 mAh g −1 is maintained over 2000 cycles at 2.0 A g −1 , and an ultrahigh capacity of 504 mAh g −1 is achieved even at ultrahigh rate of 15.0 A g −1 . Moreover, the assembled NVP@C//Co 9 S 8 /MoS 2 full‐cell can achieve excellent cycling performance, delivering a high capacity of 318 mAh g −1 over 500 cycles at 1.0 A g −1 .