Potassium-ion storage mechanism of MoS2-WS2-C microspheres and their excellent electrochemical properties

Jae Hun Choi, Gi Dae Park, Yun Chan Kang

Research output: Contribution to journalArticlepeer-review

43 Citations (Scopus)


Potassium-ion batteries are receiving increasing interest as a new type of secondary batteries because of their low redox potentials. In particular, two-dimensional transition metal dichalcogenides are being widely studied because they possess a layered structure with a large interlayer distance; these structural characteristics are favorable for hosting potassium-ions. However, capacity decay occurs and the intercalation of potassium-ions is hindered due to the huge volume expansion during the cycling process. Here, MoS2-WS2-C microspheres containing highly porous structure and heterogeneous interfaces are synthesized through facile spray pyrolysis. Benefiting from the unique structure and hetero-interfaces, the composite microspheres exhibit stable cycle performance and an outstanding rate performance. Meanwhile, a reversible capacity of 350 mA h g−1 is achieved after 100 cycles at the current density of 100 mA g−1, and even at the high current density of 5.0 A g−1, it maintains a capacity of 176 mA h g−1. The potassium-ion storage mechanism of MoS2-WS2-C microspheres is also systematically explored via ex-situ transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). With the advantages of highly reversible intercalation from WS2 and high specific capacity of conversion from MoS2, the MoS2-WS2-C microspheres achieve high rate performance and specific capacity.

Original languageEnglish
Article number127278
JournalChemical Engineering Journal
Publication statusPublished - 2021 Mar 15

Bibliographical note

Funding Information:
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF- 2019R1A2C2088047 and 2017R1A4A1014806 ).

Publisher Copyright:
© 2020


  • Molybdenum sulfide
  • Potassium-ion batteries
  • Spray pyrolysis
  • Transition metal dichalcogenide
  • Tungsten sulfide

ASJC Scopus subject areas

  • General Chemistry
  • Environmental Chemistry
  • General Chemical Engineering
  • Industrial and Manufacturing Engineering


Dive into the research topics of 'Potassium-ion storage mechanism of MoS2-WS2-C microspheres and their excellent electrochemical properties'. Together they form a unique fingerprint.

Cite this