TY - JOUR AU - Held, Marcel AU - Sennhauser, Urs PY - 2015/12/16 Y2 - 2024/03/29 TI - Stress-induced Ageing of Lithium-Ion Batteries JF - CHIMIA JA - Chimia VL - 69 IS - 12 SE - Scientific Articles DO - 10.2533/chimia.2015.737 UR - https://www.chimia.ch/chimia/article/view/2015_737 SP - 737 AB - Lithium-ion batteries are well established for use in portable consumer products and are increasingly used in high power electro-mobility and photovoltaic storage applications. In hybrid and plug-in electric vehicles degradation and useful lifetime at standard operation conditions are critical parameters in addition to performance and safety. Here stress-induced ageing of commercially available high power battery cells of the type A123 AHR32113M1 Ultra-B, consisting of a LiFePO4 cathode and a graphite anode have been investigated. A usually accepted capacity loss for electric vehicles of 20% was reached after 8560 stress profiles corresponding to a driving distance of almost 200'000 km. Cycling with a stress profile applying constant power corresponding to the average power and energy of a full stress profile and starting at 60% state of charge showed a much faster capacity loss. Electric impedance measurements show the dependence of the capacity loss and constant phase element at low frequency, indicating Li-ion diffusion blocking in the cathode. Microscopic analysis of anode, separator, and cathode, shows defect formation in bulk material and at interfaces. ER -