Thermal generation behavior of 18650 ternary LiNi0.5Co0.2Mn0.3O2 batteries was tested at working environment of 30 and 50 degrees C, respectively. The experimental results showed that the surface temperature difference of the battery at high temperature of 50 degrees C and its corresponding heating rate were both higher than those at 30 degrees C owing to the increased internal resistance, which also led to a decrease of lithium storage capacity obviously. By characterizing the crystal/nano structure of the ternary cathode materials, these phenomena could be ascribed to the damage of the crystal structure and aggregation of the electrode materials. (C) 2016 Elsevier Ltd. All rights reserved.