Triazine compounds for removing acids and water from nonaqueous electrolytes for electrochemical cells
View Patent ↗A process is provided to produce non-aqueous electrolytic solution for use in batteries having low acid content and low water content. The invention involves removing acids and water from non-aqueous electrolytic solutions typically found in lithium or lithium-ion batteries by using nitrogen-containing compounds such as triazines. After treatment by a triazine such as melamine, the concentrations of acids and water in the electrolytic solutions are substantially decreased. The present invention provides a process to prepare extremely pure electrolytic solutions having low (<20 ppm) concentrations of both water and acids.
1. A method of reducing at least one of the water content or the acid content in a non-aqueous electrolytic solution for a secondary battery comprising: contacting the non-aqueous electrolytic solution with a triazine compound, wherein the triazine compound is selected from the group consisting of
a. 2,6-bis-(2,4-dimethylphenyl)-4-(2-hydroxy-4-octyloxyphenyl)-s-triazine;
b. 2,6-bis(2,4-dimethylphenyl)-4-(2,4-dihydroxyphenyl)-s-triazine;
c. 2,4-bis(2,4-dihydroxyphenyl)-6-(4-chlorophenyl)-s-triazine;
d. 2,4-bis(2-hydroxy(2-hydroxyethoxy)phenyl)-6-(4-chlorophenyl)-s-triazine;
e. 2,4-bis(2-hydroxy-4-(2-hydroxyethoxy)phenyl)-phenyl-s-triazine;
f. 2,4-bis(2-hydroxy-4-(2-hydroxyethoxy)-phenyl)-6-(2,4-dimethylphenyl)-s-triazine;
g. 2,4-bis(2-hydroxy(2-hydroxyethoxy)phenyl)-6-(4-bromophenyl)-s-triazine;
h. 2,4-bis(2-hydroxy-4-(2-acetoryethoxy)phenyl)-6-(4-chlorophenyl)-s-triazine;
i. 2,4-bis(2,4-dihydroxyphenyl)-6-(2,4-dimethylphenyl)-1-s-triazine;
j. 2,4,6-trimethoxy-1,3,5-triazine;
k. 2,4,6-triphenyoxy-1,3,5-triazine;
l. 2,4,6-triethoxy-1,3,5-triazine;
m. 2,4,6-tripropoxy-1,3,5-triazine;
n. 2,4,6-tributoxy-1,3,5-triazine, and combinations thereof;
wherein upon contacting the non-aqueous electrolytic solution with a triazine compound, an insoluble portion of the triazine compound exists, the method further comprising removing the insoluble portion of the triazine compound.
2. The method of claim 1 wherein the triazine compound is soluble in non-aqueous electrolytic solutions to the extent of less than 5 wt %.
3. The method of claim 1 wherein the triazine compound is soluble in non-aqueous electrolytic solutions to the extent of less than 3 wt %.
4. The method of claim 1 wherein at least one of the acid content or the water content of the non-aqueous electrolytic solution is reduced by at least 10% of its original value.
5. The method of claim 1 wherein both the water content and the acid content of the non-aqueous electrolytic solution are reduced by at least 20% of their respective original values.
6. The method of claim 1 wherein at least one of the acid content or the water content of the non-aqueous electrolytic solution is reduced by at least 30% of its original value.