This need was an impetus to design a new electrochemical cell as reported herein. It integrates a pressure sensor enabling to accurately monitor with high reproducibility and sensitivity in operando pressure changes during charge/discharge without disturbing the cell system . Its friendly use is demonstrated by quantifying the amount of parasitic reaction in Li-O2 cells based on a carbon cathode with various electrolytes frequently encountered in the literature, such as LiTFSI in DME, DEGDME and TEGDME; LiNO3 in DMA , and LiClO4 in DMSO. Through this comparative study based on pneumatic data, we were able to easily observe the phenomena currently limiting the performances of Li-O2 batteries such as electrolyte instability, oxidation of the carbon electrode and the role of impurity contamination . Moreover, aging of such cells was investigated, showing for all systems a formatting process occurring during the first cycles, hence the importance of the set-up reported herein enabling easy gas monitoring over unlimited number of cycles.
Finally, this technology is directly transferable to the study of every material whose electrochemical behavior enlists gas uptake and release such as Li-rich layered compounds , organic electrode materials and other metal-air batteries.
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