Vertically grown MoS <sub>2</sub> nanosheets on graphene with defect‐rich structure for efficient sodium storage
Ying Wang, Jiapeng He, Han-Qing Pan, Qingpeng Wang, Lei Zhang, Yongchang Liu, Qinghong Wang
Abstract
Abstract The synthesis of a perpendicular growth structure of MoS 2 nanosheets on graphene for efficient sodium storage is challenging yet ideal due to the benefits of open ion diffusion channels and high electronic conductivity. In this study, we have successfully fabricated a novel structure of vertical MoS 2 nanosheets on graphene, with ZnS nanoparticles serving as bonding points (MoS 2 /ZnS/G), through a facile hydrothermal method. During the synthesis process, Zn 2+ not only acts as a landing site for the vertical growth of MoS 2 nanosheets but also triggers the formation of a defect‐rich structure in the final samples. This unique architecture of MoS 2 /ZnS/G effectively combines the advantages of a vertically aligned geometry and a defect‐rich structure for energy storage. The resulting structure displays shortened transport paths for electrons/ions, enhanced conductivity, improved structural integrity, and an increased number of active sites for promising electrochemical performance. As expected, when used as anode for sodium‐ion batteries, the as‐synthesized MoS 2 /ZnS/G exhibits excellent rate capability (high capacity of 298 mAh·g −1 at 5 A·g −1 ) and good cycling stability (a capacity decay of 0.056% per cycle after 500 cycles at 1 A·g −1 ). According to the kinetic investigations, the electrochemical process of the MoS 2 /ZnS/G sample is primarily governed by a pseudocapacitive behavior, which enhances the charge/discharge kinetics and allows the MoS 2 /ZnS/G structure to remain intact during cycling.