High voltage redox shuttles, method for making high voltage redox shuttles
The invention provides a method for producing a molecule capable of undergoing reduction-oxidation when subjected to a voltage potential, the method comprising phosphorylating hydroquinone to create a first intermediate; rearranging the first intermediate to an aryl-bis-(phosphonate) thereby creating a second intermediate comprising phosphorous alkoxy groups; alkylating (e.g., methylating) the second intermediate; converting the alkoxy groups to halides; and substituting the halides to alkyl or aryl groups. Also provided is a system for preventing overcharge in a Lithium-ion battery, the method comprising a mixture of a redox shuttle with electrolyte in the battery such that the shuttle comprises between about 10 and about 20 weight percent of the mixture.
1. A method for producing a molecule capable of undergoing reduction-oxidation when subjected to a voltage potential, the method comprising:
a. phosphorylating hydroquinone to create a first intermediate compound;
b. rearranging the first intermediate compound to an aryl-bis-(phosphonate) thereby creating a second intermediate compound comprising phosphorous alkoxy groups;
c. alkylating the second intermediate compound;
d. converting the alkoxy groups to halides; and
e. substituting the halides to alkyl or aryl groups; wherein the entire method is performed at or above a lowest temperature wherein said lowest temperature is between approximately −10° C. and approximately −20° C.
2. The method as recited in claim 1 wherein at least four phosphorous alkoxy groups are converted to halides.
3. The method as recited in claim 1 further comprising a recrystallization step to produce the molecule having better than 99 percent purity.
4. The method as recited in claim 1 wherein step c is performed at or below a highest temperature, the highest temperature about 60° C.
5. The method as recited in claim 1 wherein the highest natural reaction temperature for the conversion step is between about 75 and about 80 C.
6. The method as recited in claim 1 wherein the alkoxy groups are phosphonate esters which are chlorinated to yield aryl bis(phosphonyl dichloride).
7. The method as recited in claim 1 wherein the halide is aryl bis(phosphonyl dichloride) and the dichloride does not need to be purified prior to the substitution step.
8. The method as recited in claim 1 wherein each of the alkyl groups bonded to phosphorous contain no more than 2 carbons.
9. The molecule as produced by the method of claim 1 , whereby the molecule exhibits between about 10 and about 20 weight percent solubility in an electrolyte of a Lithium-ion battery.
10. The method of claim 1 wherein hydroquinone is 1-4 dihydroxy benzene.
11. The method of claim 1 wherein part c. is performed using solvents.
12. The method of claim 1 wherein the lowest temperature is about −15° C.