Co-doped 1T-MoS2 nanosheets embedded in N, S-doped carbon nanobowls for high-rate and ultra-stable sodium-ion batteries

• Published in: Nano research Vol. 12; no. 9; pp. 2218 - 2223
• Main Authors: Li, Peihao, Yang, Yong, Gong, Sheng, Lv, Fan, Wang, Wei, Li, Yiju, Luo, Mingchuan, Xing, Yi, Wang, Qian, Guo, Shaojun
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01.09.2019; Springer Nature B.V
• Subjects: Anodes; Atomic/Molecular Structure and Spectra; Batteries; Biomedicine; Biotechnology; Carbon; Chemistry and Materials Science; Cobalt; Condensed Matter Physics; Conductivity; Construction; Cycles; Decay rate; Doping; Electrode materials; First principles; Materials Science; Metal-organic frameworks; Molybdenum disulfide; Nanosheets; Nanostructure; Nanotechnology; Performance enhancement; Rechargeable batteries; Research Article; Sodium; Sodium-ion batteries; Stability; Structural hierarchy; Sulfurization; Synergistic effect; cobalt-doping; metal-organic framework (MOF); anode; 1T-MoS; sodium-ion battery
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-018-2250-2

Despite various 2H-MoS 2 /carbon hybrid nanostructures have been constructed and committed to improve the performance for sodium-ion batteries (SIBs), they still show the limited cycle stability due to the relatively large volumetric expansion during the charge–discharge process. Herein, we report the construction of cobalt-doped few-layered 1T-MoS 2 nanosheets embedded in N, S-doped carbon (CMS/NSC) nanobowls derived from metal-organic framework (MOF) precursor via a simple in situ sulfurization process. This unique hierarchical structure enables the uniformly dispersed Co-doped 1T-MoS 2 nanosheets intimately couple with the highly conductive carbon nanobowls, thus efficiently preventing the aggregation. In particular, the Co-doping plays a crucial role in maintaining the integrity of structure for MoS 2 during cycling tests, confirmed by first-principles calculations. Compared with pristine MoS 2 , the volume deformation of Co-doped MoS 2 can be shrunk by a prominent value of 52% during cycling. Furthermore, the few-layered MoS 2 nanosheets with 1T metallic phase endow higher conductivity, and thus can surpass its counterpart 2H semiconducting phase in battery performance. By virtue of the synergistic effect of stable structure, appropriate doping and high conductivity, the resulting CMS/NSC hybrid shows superior rate capability and cycle stability. The capacity of CMS/NSC can still be 235.9 mAh·g −1 even at 25 A·g −1 , which is 51.3% of the capacity at 0.2 A·g −1 . Moreover, the capacity can still remain 218.6 mAh·g −1 even over 8,240 cycles at 5 A·g −1 with a low decay of 0.0044% per cycle, one of the best performances among the reported MoS 2 -based anode materials for SIBs.