Deterioration Evaluation of Lithium-Ion Battery Components

This technical report presents an evaluation of the deterioration of lithium-ion battery (LiB) components using an AIRsight infrared/Raman microscope in conjunction with airtight cells. The study focuses on the positive electrode material lithium phosphate (LiFePO4), negative electrode material graphite, and polypropylene (PP) separator. The evaluation was conducted by comparing virgin and cycle samples after 100 charge/discharge cycles under controlled conditions. The report details the measurement conditions, including the use of infrared and Raman spectroscopy to analyze the structural changes in the battery components due to repeated cycling. The findings indicate that significant changes occurred in the structures of the positive and negative electrode materials, while no notable deterioration was observed in the PP separator. The AIRsight microscope's ability to perform both types of measurements simultaneously under inert conditions is highlighted as a key advantage for accurate analysis of LiB components. The report includes figures and tables that illustrate the measurement results and conditions.