Abstract
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.
Original language | English |
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Pages (from-to) | 1027-1037 |
Number of pages | 11 |
Journal | Journal of Supercritical Fluids |
Volume | 55 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2011 Jan |
Bibliographical note
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.
Keywords
- Cathode active material
- Lithium iron phosphate
- Solid-state method
- Supercritical hydrothermal synthesis
ASJC Scopus subject areas
- General Chemical Engineering
- Condensed Matter Physics
- Physical and Theoretical Chemistry