Furukawa Electric Review No.46The Quantitative Evaluation of Anode Thickness Change for Lithium-ion Batteries

Hiroko Takahashi, Masanobu Aragaki, Toshiya Hikami

The measurement technique of the electrode thickness to measure the expansion and the contraction of the electrode containing active material as height information during charge and discharge has been established. The behavior that the electrode thickness expands continuously as the number of charge and discharge cycles increases is clarified by a quantitative evaluation of the graphite based electrode and the silicon based electrode thickness and it was confirmed that from the observation of Scanning Electron Microscope (SEM), an accurate electrode thickness measurement after the charge and discharge test has been carried out. It is assumed that the volume expansion continues due to not only the expansion and the contraction behavior of the active material, but also due to the penetration of the electrolyte and the deposition of Solid Electron Interface (SEI) and etc. By observing the electrode change checking the thickness measurement result against the charge and discharge characteristics, the electrode behavior can be clarified and the information for the optimum selection of copper foil can be obtained.