Abstract
Lithium bis(pentafluoroethanesulfonyl)imide, Li[N(SO(2)C(2)F(5))(2)], a typical fluorochemical aimed at better electrochemical performance of battery electrolytes, in superheated water was studied for its waste treatment. When Li[N(SO(2)C(2)F(5))(2)] was reacted in pure superheated water at 300 °C, little F(-) ions were produced. In contrast, complete mineralization of the fluorine, sulfur, and nitrogen atoms in Li[N(SO(2)C(2)F(5))(2)] was achieved when the reaction was performed in the presence of KMnO(4). Specifically, when Li[N(SO(2)C(2)F(5))(2)] was treated for 18 h with 158 mM of KMnO(4), the F(-) and SO(4)(2-) yields were 101 and 99%, respectively, and the sum of the NO(3)(-) and NO(2)(-) yields was 101%. In the gas phase, trace CO(2) was detected and no CHF(3), which has high global warming potential, was formed. Furthermore, the fluorine, sulfur, and nitrogen atoms in the analogues K[N(SO(2)C(4)F(9))(2)] and K[N(SO(2)CF(2))(2)CF(2)] also underwent complete mineralization using the same approach.