Enhancing the safety of lithium ion batteries by 4-isopropyl phenyl diphenyl phosphate

To enhance the safety of lithium ion batteries, 4-isopropyl phenyl diphenyl phosphate (IPPP) was explored as an additive in 1.0 M LiPF6/ethylene carbonate (EC)+diethyl carbonate (DEC) (1:1 wt.%). The electrochemical performances of LiCoO2/IPPP electrolyte/C cells were tested. And then the LiCoO2/IPPP electrolyte/C cells were disassembled and wrapped to detect the thermal behaviors using a C80 microcalorimeter. The results indicated that 5% and 10% IPPP content in the electrolyte can enhance the safety of lithium ion batteries. Furthermore, the electrochemical performances of LiCoO2/IPPP electrolyte/C cells become slightly worse by using 5% and 10% IPPP content electrolyte. Therefore, 5-10% IPPP content in electrolyte can enhance the safety of lithium ion batteries with minimum sacrifice in electrochemical performance. (C) 2006 Elsevier B.V. All rights reserved.