TY - JOUR
T1 - Potassium-ion storage mechanism of MoS2-WS2-C microspheres and their excellent electrochemical properties
AU - Choi, Jae Hun
AU - Park, Gi Dae
AU - Kang, Yun Chan
N1 - 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
PY - 2021/3/15
Y1 - 2021/3/15
N2 - 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.
AB - 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.
KW - Molybdenum sulfide
KW - Potassium-ion batteries
KW - Spray pyrolysis
KW - Transition metal dichalcogenide
KW - Tungsten sulfide
UR - http://www.scopus.com/inward/record.url?scp=85092518238&partnerID=8YFLogxK
U2 - 10.1016/j.cej.2020.127278
DO - 10.1016/j.cej.2020.127278
M3 - Article
AN - SCOPUS:85092518238
VL - 408
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
SN - 1385-8947
M1 - 127278
ER -