A precise and simple temperature measurement technique during charge and discharge is applied to 5 Ah Al-laminated lithium-ion batteries (LiMn2O4/LiNi0.8Co0.15Al0.05O2 cathode and graphite anode) using a quasi-adiabatic cell holder. The obtained temperature profiles are described in terms of the reactions of the anode and cathode. This technique is applied to a cycled cell, and the capacity fading mechanism is also indicated by the temperature profiles. From the comparison between the cell temperature profiles and the reaction heat flows of the half cells in each electrode obtained by an isothermal microcalorimeter, we find that the capacity fading of the cycled cell can be derived from the capacity fading of the cathode and also from the upward shift in the operated state of charge (SOC) of the cathode in the cell. The latter shift is derived from the irreversible loss of lithium at the anode, and it leads to the misalignment of the cathode and anode operation windows. The proposed temperature measurement technique has the potential to be applied to various types of large lithium-ion batteries during operation, thus providing a new approach to analyzing the degradation of lithium-ion batteries. (C) 2013 The Electrochemical Society.