Diphenyloctyl phosphate and tris(2,2,2-trifluoroethyl) phosphite as flame-retardant additives for Li-ion cell electrolytes at elevated temperature

• Published in: Journal of power sources Vol. 180; no. 1; pp. 561 - 567
• Main Authors: Nam, Tae-Heum, Shim, Eun-Gi, Kim, Jung-Gu, Kim, Hyun-Soo, Moon, Seong-In
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.05.2008; Elsevier Sequoia
• Subjects: Applied sciences; Diphenyloctyl phosphate; Direct energy conversion and energy accumulation; Electric cells; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrochemical impedance spectroscopy; Electrolyte; Electrolytes; Electrolytic cells; Exact sciences and technology; Flame-retardant additives; High temperature; Li-ion battery; Lithium batteries; Microorganisms; Phosphates; Tris(2,2,2-trifluoroethyl) phosphite; Tris(2,2,2-trifluoroethyl) phosphite; Diphenyloctyl phosphate; Electrolyte; Li-ion battery; Flame-retardant additives; Phosphates; Scanning electron microscopy; Anode; Cathode; Flame retardant; Secondary cell; Discharge charge cycle; Lithium battery; Additive; Phosphites; Performance; Electrochemical impedance spectroscopy
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2008.01.061

The effect of diphenyloctyl phosphate (DPOF) and tris(2,2,2-trifluoroethyl) phosphite (TTFP) as flame-retardant (FR) additives in the liquid electrolyte of Li-ion cells is evaluated at both elevated temperature (40 °C) and room temperature (RT, 25 °C). The tested cells use mesocarbon microbeads (MCMB) and LiCoO 2 as the anode and cathode materials, respectively. Cell characteristics are investigated by means of electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The results of the cycle performance tests demonstrate the superior discharge capacity and capacity retention of the DPOF-containing cell compared will TTFP after cycling at both RT and 40 °C. Therefore, these results confirm the promising potential of DPOF as an FR additive for improving the electrochemical performance of Li-ion batteries.