Impedance Spectroscopy of Industrial Batteries
Starting with the very first successful measurement of a small Lead-acid battery in 1976 , we developed a set of complementary techniques providing for reliable measurements of battery impedances, data handling and analysis. The techniques for inductive errors evaluation and correction, for the 4-Dimentional data treatment  of the evolving battery State of Charge will be discussed in details. Special attention will be given to the interpretation of the battery impedance as a property of a fuzzy system with un-known parameters distribution. The Differential Impedance Analysis which solves this problem and the related Spectral Transforms are powerful tools for batteries evaluation and quality control .
These techniques will be illustrated with practical examples of impedance measurements of large industrial Lead-acid and Li-ion batteries and stacks fabricated by different technologies and for different purposes.
Some related side phenomena as: (i) presence and destruction of the passive layer; (ii) increased inductance of stacks as well as impedance observation of local in-homogeneities in Li-ion batteries will be also discussed.
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