Electrical insulation properties of RF-sputtered LiPON layers towards electrochemical stability of lithium batteries. (3rd November 2016)

• Record Type: Journal Article
• Authors: Vieira, E M F; Ribeiro, J F; Silva, M M; Barradas, N P; Alves, E; Alves, A; Correia, M R; Goncalves, L M
• Is Part Of: Journal of physics. Volume 49:Number 48(2016)
• Publication Date: 2016-11-03
• Subjects: lithium battery -- LiPON electrolyte -- RF sputtering -- electrical insulation -- electrochemical stability; Physics -- Periodicals; 530
• DOI: 10.1088/0022-3727/49/48/485301
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: Electrochemical stability, moderate ionic conductivity and low electronic conductivity make the lithium phosphorous oxynitride (LiPON) electrolyte suitable for micro and nanoscale lithium batteries. The electrical and electrochemical properties of thin-film electrolytes can seriously compromise full battery performance. Here, radio-frequency (RF)-sputtered LiPON thin films were fabricated in nitrogen plasma under different working pressure conditions. With a slight decrease in the deposition pressure from 6 to 1 × 10 −3 mbar, the 600 nm thick LiPON film reveals an electric resistivity increase from 10 8 to 10 10 Ω · cm, respectively. UV– micro-Raman spectroscopy confirms the nitrogen incorporation on the Li3 PO4 material, while scanning electron microscopy, Rutherford backscattering spectrometry and nuclear reaction analysis show a well-defined compact structure with a composition of Li2.2 PO2.2 N0.6 for the higher electrical-resistivity film. An ionic conductivity close to 3 × 10 −7 S cm −1 at room temperature (22 °C) was measured by AC impedance spectroscopy. Thermal properties were investigated through the differential scanning calorimetry technique. LiPON films reveal high optical transmission (>75%) in the UV–vis range, which could be interesting for transparent electronic devices.