Varta Microbattery Gmbh

Andrea Droisner

Stefan Koller

Harald Kren

A method of producing an electrochemical cell includes introducing lithium into the electrochemical cell such that an amount of mobile lithium contained in the cell available for incorporation and releasing processes in electrodes exceeds, after formation, the capacity of at least one positive electrode for taking up lithium at least by a factor of 1.1, and the at least one negative electrode in terms of its capacity for taking up lithium is dimensioned to a size sufficient to be capable of taking up the entire mobile lithium contained in the cell after formation, wherein the lithium is introduced at least partially into the electrochemical cell via the at least one negative electrode by pre-lithiating the at least one negative electrode prior to combination with the at least one positive electrode or by applying metallic lithium on a surface of the at least one negative electrode.

Lithium ion cell having improved ageing behavior

A formed, secondary electrochemical cell includes at least one positive electrode containing a metal compound capable of reversibly incorporating and releasing lithium in the form of ions, at least one negative electrode containing a carbon compound capable of reversibly incorporating or releasing lithium in the form of ions, and/or a metal and/or semi-metal which can be alloyed with lithium, an electrolyte via which lithium ions can migrate between the at least one positive electrode and the at least one negative electrode, and mobile lithium available for incorporation or releasing processes in the electrodes, wherein capacity of the at least one negative electrode for taking up lithium is higher than that of the at least one positive electrode, the at least one negative electrode has a higher capacity than required for taking up the entire mobile lithium contained in the cell, and the mobile lithium is contained in the cell in an amount which exceeds the capacity of the at least one positive electrode for taking up lithium.

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Bartholomä, Austria

Andrea Droisner