In situ high-resolution transmission electron microscopy synthesis observation of nanostructured carbon coated LiFePO4
| Autor: | R. Veillette, Alessandra M. Serventi, Karim Zaghib, Michel L. Trudeau, Alain Mauger, C.M. Julien, Dharminder Laul |
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| Rok vydání: | 2011 |
| Předmět: |
Materials science
Ethylene oxide Renewable Energy Sustainability and the Environment Annealing (metallurgy) Ultra-high vacuum Energy Engineering and Power Technology Mineralogy Polyethylene law.invention chemistry.chemical_compound chemistry Chemical engineering Transmission electron microscopy law Electrical and Electronic Engineering Physical and Theoretical Chemistry Electron microscope High-resolution transmission electron microscopy Ethylene glycol |
| Zdroj: | Journal of Power Sources. 196:7383-7394 |
| ISSN: | 0378-7753 |
| DOI: | 10.1016/j.jpowsour.2011.04.003 |
| Popis: | In situ high-resolution transmission electron microscopy (HRTEM) studies of the structural transformations that occur during the synthesis of carbon-coated LiFePO 4 (C–LiFePO 4 ) and heat treatment to elevated temperatures were conducted in two different electron microscopes. Both microscopes have sample holders that are capable of heating up to 1500 °C, with one working under high vacuum and the other capable of operating with the sample surrounded by a low gaseous environment. The C–LiFePO 4 samples were prepared using three different compositions of precursor materials with Fe(0), Fe(II) or Fe(III), a Li-containing salt and a polyethylene- block -poly(ethylene glycol)-50% ethylene oxide or lactose. The in situ TEM studies suggest that low-cost Fe(0) and a low-cost carbon-containing compound such as lactose are very attractive precursors for mass production of C–LiFePO 4 , and that 700 °C is the optimum synthesis temperature. At temperatures higher than 800 °C, LiFePO 4 has a tendency to decompose. The same in situ measurements have been made on particles without carbon coat. The results show that the homogeneous deposit of the carbon deposit at 700 °C is the result of the annealing that cures the disorder of the surface layer of bare LiFePO 4 . Electrochemical tests supported the conclusion that the C–LiFePO 4 derived from Fe(0) is the most attractive for mass production. |
| Databáze: | OpenAIRE |
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