Characteristics of Amorphous Lithium Lanthanum Titanate Electrolyte Thin Films Grown by PLD for Use in Rechargeable Lithium Microbatteries

(Li0.5La0.5)TiO3 (LLTO) film electrolytes for use in a lithium rechargeable microbattery were prepared on a Pt collector using pulsed laser deposition (PLD) at various deposition temperatures. As-grown 360 nm thick LLTO films prepared at 400-600 C showed an amorphous phase and an ionic conductivity of about 2.0 x 10 exp(-5) S/cm at room temperature. A lithium metal anode in contact with the amorphous LLTO films had no influence on the electronic conductivity of the LLTO solid-electrolyte, contrary to crystalline films. The retention capacity of the LLTO/100 nm thick LiCoO2/Pt cells during 100 cycles in a 1 M LiClO4 liquid electrolyte in propylene carbonate was about 82.2% and the cells exhibited an increase of about 30% compared with that for LiCoO2/Pt cells. The LLTO/LiCoO2/Pt cells had excellent rechargeability characteristies of about 63% up to 300 cycles. 19 refs.