In the present study, the gaseous decomposition products from polycarbonate and polyester-based SPEs are traced by online electrochemical mass spectrometry (OEMS). An operando characterization of the evolved gases from poly(trimethylene carbonate) (PTMC)-derived SPEs using high-molecular-weight PTMC and its copolymer as the host materials is performed under both cathodic reduction and anodic oxidation regions at close to ambient temperatures (e.g., 30 °C, 50 °C). Direct correlations between the oxidation and reduction potentials with the gas evolution are observed; the evolutions of CO2 (m/z = 44) and CH4 (m/z = 16) are traced and compared with LiTFSI-containing carbonate liquid electrolyte. Meanwhile, additional gaseous products are detected, such as SO2 (m/z = 64), which could be assigned to LiTFSI decomposition. This was indicated from the detectable salt decomposition residuals in Li-cells using PTMCnLiTFSI-based SPEs by X-ray photoelectron spectroscopy (XPS) .
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 B. Sun, C. Xu, J. Mindemark, T. Gustafsson, K. Edström, D. Brandell, J. Mater. Chem. A, 3 (2015) 13994-14000.