Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
193238 | Electrochimica Acta | 2009 | 5 Pages |
LiFePO4 thin films have been prepared by pulsed laser deposition method on titanium substrates. The influence of the deposition parameters, e.g. substrate temperature, ambient argon pressure, and post-annealing on the crystallinity and morphology of as-deposited thin films are investigated. Well-crystallized pure olivine-phase is obtained under optimized deposition condition (20–30 Pa, 500 °C). It shows a high electrochemical activity (83% theoretical capacity) at low current density (0.33 μA cm−2, 1/20 C) and elevated testing temperature (45 °C). Moderate post-annealing treatment can enhance the utilization of the films further. The deposition of the film at a too high temperature or post-annealing for too long time could introduce Fe3+ impurities, i.e., Li3Fe2(PO4)3 and Fe4(P2O7)3, which can be easily detected by extending the electrochemical test voltage down to 2.5 V.