Performance of electrolyte with dimethyl methyl phosphonate as flame-retardant additive
(1. Department of Chemistry, South China Normal University, Guangzhou 510006, China;
2. College of Materials Science and Engineering, South China University of Technology,
Guangzhou 510641, China;
3. Guangzhou Tinci High New Material Technology Trade Co. Ltd., Guangzhou 510600, China)
2. College of Materials Science and Engineering, South China University of Technology,
Guangzhou 510641, China;
3. Guangzhou Tinci High New Material Technology Trade Co. Ltd., Guangzhou 510600, China)
Abstract: To improve the safety of lithium-ion batteries, dimethyl methyl phosphonate(DMMP) was used as a flame-retardant additive in a LiPF6 electrolyte solution. The flammability and thermal stability of DMMP-containing electrolyte was investigated by means of burning test and accelerating rate calorimeter. It was found that the flammability and self-heat rate of the electrolyte can be reduced by the addition of DMMP. On the other hand, the electrochemical performances of graphite/LiCoO2 cells become slightly worse after using DMMP additive in the electrolyte. This alleviated trade-off between electrolyte flammability, thermal stability, and cell performance provides a possibility to formulate a nonflammable electrolyte containing DMMP and improve the electrolyte thermal stability with a minimal sacrifice in performance.
Key words: lithium ion batteries; dimethyl methyl phosphonate(DMMP); fame-retardant