TY - JOUR
T1 - Small capacity decay of lithium iron phosphate (LiFePO4) synthesized continuously in supercritical water
T2 - Comparison with solid-state method
AU - Hong, Seung Ah
AU - Kim, Su Jin
AU - Kim, Jaehoon
AU - Chung, Kyung Yoon
AU - Cho, Byung Won
AU - Kang, Jeong Won
N1 - Funding Information:
This research was supported by Clean Technology Program through the Korea Evaluation Institute of Industrial Technology funded by the Ministry Knowledge Economy ( KC000646 ). The authors acknowledge Global Research Lab. Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (MEST) (grant number: 2010-00351) for additional support.
PY - 2011/1
Y1 - 2011/1
N2 - Nanosize lithium iron phosphate (LiFePO4) particles are synthesized using a continuous supercritical hydrothermal synthesis method at 25 MPa and 400 °C under various flow rates. The properties of LiFePO 4 synthesized in supercritical water including purity, crystallinity, atomic composition, particle size, surface area and thermal stability are compared with those of particles synthesized using a conventional solid-state method. Smaller size particles ranging 200-800 nm, higher BET surface area ranging 6.3-15.9 m2 g-1 and higher crystallinity are produced in supercritical water compared to those of the solid-state synthesized particles (3-15 μm; 2.4 m2 g-1). LiFePO4 synthesized in supercritical water exhibit higher discharge capacity of 70-80 mAh g-1 at 0.1 C after 30 cycles than that of the solid-state synthesized LiFePO4 (60 mAh g-1), which is attributed to the smaller size particles and the higher crystallinity. Smaller capacity decay at from 135 to 125 mAh g-1 is observed during the 30 cycles in carbon-coated LiFePO4 synthesized using supercritical water while rapid capacity decay from 158 to 140 mAh g-1 is observed in the carbon-coated LiFePO4 synthesized using the solid-state method.
AB - Nanosize lithium iron phosphate (LiFePO4) particles are synthesized using a continuous supercritical hydrothermal synthesis method at 25 MPa and 400 °C under various flow rates. The properties of LiFePO 4 synthesized in supercritical water including purity, crystallinity, atomic composition, particle size, surface area and thermal stability are compared with those of particles synthesized using a conventional solid-state method. Smaller size particles ranging 200-800 nm, higher BET surface area ranging 6.3-15.9 m2 g-1 and higher crystallinity are produced in supercritical water compared to those of the solid-state synthesized particles (3-15 μm; 2.4 m2 g-1). LiFePO4 synthesized in supercritical water exhibit higher discharge capacity of 70-80 mAh g-1 at 0.1 C after 30 cycles than that of the solid-state synthesized LiFePO4 (60 mAh g-1), which is attributed to the smaller size particles and the higher crystallinity. Smaller capacity decay at from 135 to 125 mAh g-1 is observed during the 30 cycles in carbon-coated LiFePO4 synthesized using supercritical water while rapid capacity decay from 158 to 140 mAh g-1 is observed in the carbon-coated LiFePO4 synthesized using the solid-state method.
KW - Cathode active material
KW - Lithium iron phosphate
KW - Solid-state method
KW - Supercritical hydrothermal synthesis
UR - http://www.scopus.com/inward/record.url?scp=78650252120&partnerID=8YFLogxK
U2 - 10.1016/j.supflu.2010.09.026
DO - 10.1016/j.supflu.2010.09.026
M3 - Article
AN - SCOPUS:78650252120
SN - 0896-8446
VL - 55
SP - 1027
EP - 1037
JO - Journal of Supercritical Fluids
JF - Journal of Supercritical Fluids
IS - 3
ER -