TY - JOUR
T1 - Conversion reaction mechanism of cobalt telluride-carbon composite microspheres synthesized by spray pyrolysis process for K-ion storage
AU - Yang, Sungjin
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).
PY - 2020/11/1
Y1 - 2020/11/1
N2 - Owing to its similarity to lithium and sodium, potassium has been increasingly used to fabricate potassium ion batteries (KIBs). Following vigorous attempts to identify highly efficient electrode materials, transition metal chalcogenide materials have been identified as promising candidates. In this study, the performance of metal telluride (cobalt telluride) as new anode material for KIBs is investigated. Cobalt telluride-C (CoTe2-C) composite microspheres are synthesized using spray pyrolysis. Thereafter, a facile one-step post-treatment process results in the formation of pure-phase CoTe2-C composite microspheres with uniform composition, owing to the direct embedding of Te within the composite microspheres. Conversely, tellurization via application of H2Te gas results in inhomogeneous CoTe2-C composite microspheres, arising from crystal growth of CoTe2, owing to Ostwald ripening. The conversion reaction mechanism of CoTe2-C microspheres for K-ion storage has been examined using in-situ and ex-situ measurements and the reversible reaction mechanism from the second cycle of the reaction of CoTe2 with K ions, described by the reaction: 2Co + K5Te3 + K2Te ↔ 2CoTe + 2Te + 7 K+ + 7e−. Additionally, at a current density of 0.5 A g−1, the discharge capacity of the CoTe2-C composite was 189.5 mA h g−1 for the 100th cycle.
AB - Owing to its similarity to lithium and sodium, potassium has been increasingly used to fabricate potassium ion batteries (KIBs). Following vigorous attempts to identify highly efficient electrode materials, transition metal chalcogenide materials have been identified as promising candidates. In this study, the performance of metal telluride (cobalt telluride) as new anode material for KIBs is investigated. Cobalt telluride-C (CoTe2-C) composite microspheres are synthesized using spray pyrolysis. Thereafter, a facile one-step post-treatment process results in the formation of pure-phase CoTe2-C composite microspheres with uniform composition, owing to the direct embedding of Te within the composite microspheres. Conversely, tellurization via application of H2Te gas results in inhomogeneous CoTe2-C composite microspheres, arising from crystal growth of CoTe2, owing to Ostwald ripening. The conversion reaction mechanism of CoTe2-C microspheres for K-ion storage has been examined using in-situ and ex-situ measurements and the reversible reaction mechanism from the second cycle of the reaction of CoTe2 with K ions, described by the reaction: 2Co + K5Te3 + K2Te ↔ 2CoTe + 2Te + 7 K+ + 7e−. Additionally, at a current density of 0.5 A g−1, the discharge capacity of the CoTe2-C composite was 189.5 mA h g−1 for the 100th cycle.
KW - Chalcogenide materials
KW - Cobalt telluride
KW - Conversion mechanism
KW - Potassium ion batteries
KW - Spray pyrolysis
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U2 - 10.1016/j.apsusc.2020.147140
DO - 10.1016/j.apsusc.2020.147140
M3 - Article
AN - SCOPUS:85087587513
VL - 529
JO - Applied Surface Science
JF - Applied Surface Science
SN - 0169-4332
M1 - 147140
ER -