TY - JOUR
T1 - Carbon/two-dimensional MoTe2 core/shell-structured microspheres as an anode material for Na-ion batteries
AU - Cho, Jung Sang
AU - Ju, Hyeon Seok
AU - Lee, Jung Kul
AU - Kang, Yun Chan
N1 - Funding Information:
This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (NRF-2015R1A2A1A15056049). This work was supported by the Energy Efficiency and Resources Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry and Energy, Republic of Korea (201320200000420 and 20153030091450).
PY - 2017/2/7
Y1 - 2017/2/7
N2 - Unique-structured composite microspheres of carbon and MoTe2 were prepared by a two-step process. Precursor C-MoOx composite microspheres were prepared by spray pyrolysis, and then the precursor was transformed into C-MoTe2 composite microspheres by a tellurization process. C-MoTe2 composites with a uniform distribution of MoTe2 nanocrystals (C/MoTe2) and core-shell-structured C-MoTe2 composites (C@MoTe2) were synthesized at tellurization temperatures of 450 and 600 °C, respectively. At a higher tellurization temperature of 600 °C, all of the MoTe2 nanocrystals moved to the surface of the microsphere because of the Ostwald ripening process. The initial discharge capacities of the C/MoTe2, C@MoTe2, and bare MoTe2 (i.e., containing no carbonaceous materials) powders for Na-ion storage at a current density of 1.0 A g-1 were 328, 388, and 341 mA h g-1, respectively. The discharge capacities of the C/MoTe2, C@MoTe2, and bare MoTe2 powders for the 200th cycle were 241, 286, and 104 mA h g-1, respectively, and the corresponding capacity retentions, which were measured from the second cycle were 100%, 99%, and 37%, respectively. The high structural stability and well-developed two-dimensional layer of MoTe2 of the C@MoTe2 microspheres provide superior Na-ion storage properties compared to those of the C/MoTe2 microspheres and bare MoTe2 powder.
AB - Unique-structured composite microspheres of carbon and MoTe2 were prepared by a two-step process. Precursor C-MoOx composite microspheres were prepared by spray pyrolysis, and then the precursor was transformed into C-MoTe2 composite microspheres by a tellurization process. C-MoTe2 composites with a uniform distribution of MoTe2 nanocrystals (C/MoTe2) and core-shell-structured C-MoTe2 composites (C@MoTe2) were synthesized at tellurization temperatures of 450 and 600 °C, respectively. At a higher tellurization temperature of 600 °C, all of the MoTe2 nanocrystals moved to the surface of the microsphere because of the Ostwald ripening process. The initial discharge capacities of the C/MoTe2, C@MoTe2, and bare MoTe2 (i.e., containing no carbonaceous materials) powders for Na-ion storage at a current density of 1.0 A g-1 were 328, 388, and 341 mA h g-1, respectively. The discharge capacities of the C/MoTe2, C@MoTe2, and bare MoTe2 powders for the 200th cycle were 241, 286, and 104 mA h g-1, respectively, and the corresponding capacity retentions, which were measured from the second cycle were 100%, 99%, and 37%, respectively. The high structural stability and well-developed two-dimensional layer of MoTe2 of the C@MoTe2 microspheres provide superior Na-ion storage properties compared to those of the C/MoTe2 microspheres and bare MoTe2 powder.
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U2 - 10.1039/c6nr07158a
DO - 10.1039/c6nr07158a
M3 - Article
C2 - 28098302
AN - SCOPUS:85011319781
VL - 9
SP - 1942
EP - 1950
JO - Nanoscale
JF - Nanoscale
SN - 2040-3364
IS - 5
ER -