Developments of high-voltage all-solid-state thin-film lithium ion batteries

• Published in: Journal of power sources 2006-03, Vol.154 (1), p.232-238
• Main Authors: Schwenzel, J., Thangadurai, V., Weppner, W.
• Format: Article
• Language: English
• Subjects: All-solid-state batteries; Applied sciences; Chemical diffusion coefficient; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Exact sciences and technology; Li-ion batteries
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2005.03.223

Powders of Li 2MMn 3O 8 (M = Fe, Co) were prepared by glycine nitrate combustion from the corresponding metal nitrates. The reaction products were pressed into pellets with the addition of 20 wt.% excess LiNO 3, which were used as targets for e-beam evaporation. A high-voltage all-solid-state thin-film lithium ion battery was demonstrated by the sequential deposition of spinel structured Li 2MMn 3O 8 (M = Co, Fe) as positive electrode by e-beam evaporation, LiPON as electrolyte, and metallic Al as negative electrode by sputtering in N 2 and Ar gas mixtures with specific power and gas flow rates. A lithium ion conductivity of ∼10 −6 S cm −1 was observed for the optimized thin-film LiPON electrolyte prepared under the condition of a chamber pressure of 2.6 × 10 −2 mbar and a power of 60–100 W. The chemical diffusion coefficient ( D ˜ ) was found to be in the range 10 −13 to 10 −12 cm 2 s −1 for any composition x of Li 2− x MMn 3O 8 (M = Fe, Co) in the range from 0.1 to 1.6 by employing the galvanostatic intermittent titration technique (GITT). AC impedance studies revealed a charge transfer resistance of 260–290 Ω, a double layer capacity of ∼45–70 μF for an electrode area of 6.7 cm 2.