A Novel Flame-Retardant Additive for Lithium Batteries

摘要

The electrochemical and thermal properties of nonaqueous electrolytes containing a flame-retardant additive hexamethoxycyclotriphosphazene ([NP(OCH_3)_2]_3) were measured using cyclic voltammetry, electrochemical cycling, differential scanning calorimetery, and accelerating rate calorimetery. The flame-retardant additive was synthesized by reacting sodium methoxide (NaOCH_3) and hexachlorocyclotriphosphazene (NPCl_2)_3. The electrochemical stability of the electrolyte was determined using cyclic voltammetry. A mixture of 1 M lithium hexafluorophosphate and ethylene carbonate-dimethyl carbonate (50:50 wt %) was used as electrolyte. Li/LiNi_(0.8)Co_(0.2)O_2 cells were fabricated with and without the flame-retardant additive to study their electrochemical performance.