Design and validation of an online partial and total pressure measurement system for Li-ion cells

JOURNAL OF POWER SOURCES

卷:485

Article

Lundstrom, Robin¹  Berg, Erik J.¹ 

[1] Uppsala Univ, Angstrom Lab, Dept Chem, Box 538, SE-75121 Uppsala, Sweden

关键词: Li-ion batteries;    LiCoO2 decomposition;    Gas evolution;    Side-reactions;    Online electrochemical mass spectrometry;   

DOI  :  10.1016/j.jpowsour.2020.229347

来源: Elsevier

【 摘 要 】

Online Electrochemical Mass Spectrometry (OEMS) provides unparalleled access to the details of electrode/electrolyte interfacial reactions in electrochemical systems. Herein, the development and validation of an OEMS system along with detailed calibration protocols and limits of detection sensitivity are showcased. Combined partial and total pressure monitoring provides a clear advantage when detailing major and minor gas reactions as well as when determining unaccounted gases. A classical Li-ion LiCoO2/Graphite full cell is studied during overcharge to 4.9 V vs. Li+/Li at 50 degrees C at an unprecedented level of detail and the results are compared to LiCoO2/LiFePO4 and Graphite/LiFePO4 cells in order to differentiate between gases forming at the anode and cathode. The release of O-2 from LixCoO2 (x < 0.4) during both charge and discharge demonstrates that its degradation is dependent on state of charge 1-x rather than potential. The presented methodology establishes an improved experimental basis for deeper understanding of interfacial reactions in batteries and electrochemical systems alike.

【 授权许可】

Free