D. P. Kong, P. Ping, Q. S. Wang and J. H. Sun (2016) Study on High Temperature Stability of LiNi0.33Co0.33Mn0.33O2/Li4Ti5O12 Cells from the Safety Perspective. Journal/Journal Of the Electrochemical Society 163 A1697-A1704. [In English]
Web link: http://dx.doi.org/10.1149/2.1041608jes
Keywords: ,TITANIUM-OXIDE ANODE, LITHIUM-ION BATTERY, HIGH-POWER BATTERY, CYCLE, LIFE, ACCELERATING RATE, SYSTEM, CALORIMETRY, LI4TI5O12, CALENDAR, CATHODES

Abstract: The electrochemical and thermal stability of LiNi0.33Co0.33Mn0.33O2/Li4Ti5O12 (LNCMO/LTO) cells at high temperature is investigated using a cycler, calorimetry analysis and X-ray diffractometry (XRD) from the safety perspective. Outstanding cycling performance and rate capability are observed for LNCMO/LTO cells at room and high temperature. The cells retain 96.9% and 95.3% capacity and more than 99% coulomb efficiency over 100 cycles under C/2 rate, and also exhibit 91.6% and 84.9% capacity retention under 5C rate, at 25 and 60 degrees C, respectively. Detailed thermal analysis of the LNCMO/LTO cell revealed the reaction course from 50 to 300 degrees C, which can be summarized as melting of the separator, the reaction between PF5 and lithium intercalated in LTO, the reaction between solvents and lithium intercalated in LTO, the decomposition of LNCMO and the oxidization of solvents. The thermal analysis also indicates that the cells are thermally stable below 150 degrees C and the greatest contribution to the heat generation is the decomposition of LNCMO and the oxidization of solvents. (C) 2016 The Electrochemical Society. All rights reserved.