Morphology mediation of MoS2 nanosheets with organic cations for fast sodium ion storage

• Published in: Chinese chemical letters 2021-02, Vol.32 (2), p.880-884
• Main Authors: Li, Jinjin, Liu, Congcong, Wei, Jingjiang, Yan, Yuantao, Zhao, Xiaoli, Yang, Xiaowei
• Format: Article
• Language: English
• Subjects: Anti-restacking; Crumpled MoS2 nanosheets; Ion diffusion kinetics; Na-ion storage; Organic cations
• ISSN: 1001-8417; 1878-5964
• DOI: 10.1016/j.cclet.2020.06.036

The morphology mediation of MoS2 nanosheets via a facile coagulation method is firstly reported.The abundant sheet crumples were induced, which greatly enhance their surface accessibility and thus benefit the Na-ion diffusion kinetics. Importantly, the special role of organic cations in the inter-sheet assembly configuration was demonstrated, in sharp contrast with that of alkali/alkaline-earth ones. [Display omitted] Ion diffusion kinetics, depending on the size, tortuosity, connectivity of the channels, greatly affects the rate performance of the electrodes. Two-dimensional materials (2DMs) has emerged as promising electrode materials in the past decades. However, the applications of 2DMs electrodes are limited by the strong restacking problem, which leads to a poor rate capability. In this work, we for the first time mediated the morphology of molybdenum disulfide (MoS2) nanosheets via a facile coagulation method; abundant sheet crumples were induced, which greatly enhance their surface accessibility and thus benefit the ion diffusion kinetics. Consequently, the crumpled-MoS2 electrodes follow a capacitive Na-ion charge-storage mechanism to a large extent. Importantly, we demonstrate the special role of organic cations in the inter-sheet assembly configuration, in sharp contrast with that of alkali/alkaline-earth ones. We propose that organic cations cause edge/face contact of the sheets, instead of the face/face contact, thus affording a house-of-cards structure.