Co‐Construction of Sulfur Vacancies and Heterojunctions in Tungsten Disulfide to Induce Fast Electronic/Ionic Diffusion Kinetics for Sodium‐Ion Batteries
Yu Li, Ji Qian, Minghao Zhang, Shuo Wang, Zhaohua Wang, Maosheng Li, Ying Bai, Qinyou An, Huajie Xu, Feng Wu, Liqiang Mai, Chuan Wu
Abstract
Abstract Engineering novel electrode materials with unique architectures has a significant impact on tuning the structural/electrochemical properties for boosting the performance of secondary battery systems. Herein, starting from well‐organized WS 2 nanorods, an ingenious design of a one‐step method is proposed to prepare a bimetallic sulfide composite with a coaxial carbon coating layer, simply enabled by ZIF‐8 introduction. Rich sulfur vacancies and WS 2 /ZnS heterojunctions can be simultaneously developed, that significantly improve ionic and electronic diffusion kinetics. In addition, a homogeneous carbon protective layer around the surface of the composite guarantees an outstanding structural stability, a reversible capacity of 170.8 mAh g −1 after 5000 cycles at a high rate of 5 A g −1 . A great potential in practical application is also exhibited, where a full cell based on the WS 2− x /ZnS@C anode and the P2‐Na 2/3 Ni 1/3 Mn 1/3 O 2 cathode can maintain a reversible capacity of 89.4 mAh g −1 after 500 cycles at 1 A g −1 . Moreover, the underlying electrochemical Na storage mechanisms are illustrated in detail by theoretical calculations, electrochemical kinetic analysis, and operando X‐ray diffraction characterization.