Preparings And Properties Of Lithium Ion Solid State Electrolytic Thin Films

Lithium ion solid state electrolytic thin films have many advantages, such as high chemical stability and safety, which can be applied to the electrochromic devices, electrochemical sensors, and lithium batteries. LLTO and LiPON thin films have been widely used for solid state electrolyte thin films because of their high lithium ion conductivity and favorable electrochemical stability.We sintered La0.56Li0.33TiO3 ceramic target with Li2CO3, TiO2 and La2O3 powders. LLTO thin films were prepared on ITO glass and Si substrates by RF-magnetron sputtering, whose argon oxygen ratio, working pressure, sputtering power were 10sccm:10sccm,1.5Pa and 100W respectively. Besides, the effects of annealing temperature on structures, morphologies, optical and electrical properties of LLTO thin films are studied. LLTO thin films coated under room temperature are amorphous, and its ion conductivity and transmittance in visible range are improved as annealing temperature increasing. After annealing under Ar atmosphere at 300?,the ion conductivity and transmittance are 5.0×10-6Scm-1, and 89% respectively.Li3PO4 ceramic target was sintered with Li3PO4 powder. LiPON thin films were prepared on ITO glass substrates by RF-magnetron sputtering. The effects of sputtering pressure, sputtering power and nitrogen flux on the film coating speed were studied. We get the best coating speed when the processing parameters are 1.5Pa pressure,120W sputtering power and 30sccm nitrogen flux. Furthermore, the effects of sputtering power on surface morphology and ion conductivity of thin films are studied. The ion conductivity rises as sputtering power increasing and gets 6.1×10-7Scm-1 when sputtering power is 120W.LLTO, LiPON and LLTO/LiPON/LLTO solid thin film electrolytes were applied to single substrate electrochromic device respectivly. Their electrochromic properties were tested after applying 3V DC power.