Details

Autor(en) / Beteiligte

• Delacourt, Charles
• Poizot, Philippe
• Tarascon, Jean-Marie
• Masquelier, Christian

Titel

The existence of a temperature-driven solid solution in LixFePO4 for 0 ≤ x ≤ 1

Ist Teil von

• Nature materials, 2005-03, Vol.4 (3), p.254-260

Ort / Verlag

London: Nature Publishing Group

Erscheinungsjahr

2005

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Lithium-ion batteries have revolutionized the powering of portable electronics. Electrode reactions in these electrochemical systems are based on reversible insertion/deinsertion of Li+ ions into the host electrode material with a concomitant addition/removal of electrons into the host. If such batteries are to find a wider market such as the automotive industry, less expensive positive electrode materials will be required, among which LiFePO4 is a leading contender. An intriguing fundamental problem is to understand the fast electrochemical response from the poorly electronic conducting two-phase LiFePO4 /FePO4 system. In contrast to the well-documented two-phase nature of this system at room temperature, we give the first experimental evidence of a solid solution Lix FePO4 (0 ≤ x ≤ 1) at 450 °C, and two new metastable phases at room temperature with Li0.75 FePO4 and Li0.5 FePO4 composition. These experimental findings challenge theorists to improve predictive models commonly used in the field. Our results may also lead to improved performances of these electrodes at elevated temperatures.