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The Influence of Different Post‐Drying Procedures on Remaining Water Content and Physical and Electrochemical Properties of Lithium‐Ion Batteries
Author(s) -
Huttner Fabienne,
Haselrieder Wolfgang,
Kwade Arno
Publication year - 2020
Publication title -
energy technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 44
eISSN - 2194-4296
pISSN - 2194-4288
DOI - 10.1002/ente.201900245
Subject(s) - electrochemistry , coulometry , electrolyte , lithium (medication) , water content , materials science , electrode , battery (electricity) , chemical engineering , titration , lithium ion battery , separator (oil production) , chemistry , inorganic chemistry , engineering , power (physics) , physics , quantum mechanics , thermodynamics , medicine , geotechnical engineering , endocrinology
The post‐drying of electrodes and separators for lithium‐ion batteries just before cell assembly aims at reducing the water content in the cells below a critical value. This is important as the remaining water can lead to cell degradation and thus cause a safety risk. In addition, it can impede the formation of an effective solid electrolyte interface. Nevertheless, the post‐drying of lithium‐ion battery electrodes and separators is still poorly investigated. Considering this, three different post‐drying procedures are investigated on pouch cells and compared with the non‐post‐dried state. The remaining water contents are measured via coulometric Karl Fischer Titration and correlated to the resulting electrochemical performance. Surprisingly, the most intensely post‐dried cells show the worst electrochemical performance despite reaching the lowest water content. In contrast, the mildest post‐dried cells, which show the highest water content, achieve the best electrochemical performance. Further analyses show that extreme post‐drying can cause irreparable damages within the electrode structures. Therefore, a good electrochemical performance is not only guaranteed by low remaining water content but also, in particular, by gentle post‐drying.