Dahn's patent on fluorinated alkoxybenzene derivatives

http://www.google.com/patents?id=1RYCAgAAEBAJ&printsec=frontcover&dq=Redox+shuttles+for+high+voltage+cathodes&source=bl&ots=3pTaki2M4H&sig=S66F-BlIKxrSvwxEBAlllbaCaFs&hl=en&sa=X&ei=G2Y_UOSwLcm42wXv3IHIDQ&ved=0CC8Q6AEwAA

1. A rechargeable electrochemical cell comprising:

a positive electrode having at least one electroactive material having a recharged potential;

a negative electrode;

a charge-carrying electrolyte comprising a charge carrying medium and an electrolyte salt; and

a cyclable redox chemical shuttle comprising an aromatic compound substituted with at least one tertiary alkyl group and at least one halogenated alkoxy group, dissolved in or dissolvable in the electrolyte and having an oxidation potential above the recharged potential of at least one of the electroactive materials of the positive electrode principal electroactive material.

2. The cell according to claim 1, wherein at least one alkoxy group comprises a fluorinated alkoxy group.

3. The cell according to claim 2, wherein the partially fluorinated alkoxy group comprises from one to about four carbon atoms.

4. The cell according to claim 3, wherein the partially fluorinated alkoxy group(s) are selected from —OCH2F, —OCH2CF3, —OCH2CF2CF3, —OCH2CF2CF2CF3, —OCH2CF2CF2H and —OCH2CF2CFHCF3.

5. The cell according to claim 1, wherein the aromatic compound is substituted with at least two tertiary alkyl groups and at least two halogenated alkoxy groups.

6. The cell according to claim 1, wherein at least one tertiary alkyl group comprises a butyl group.

7. The cell according to claim 1, wherein the shuttle comprises a compound having the formula:

wherein R1 and R2 can each, independently, be H or a tertiary alkyl group with four to twelve carbon atoms, wherein at least one of R1 or R2 is a tertiary alkyl group, wherein each Rf can, independently, be H or a halogenated alkoxy group having the formula —OR′ where R′ is a halogenated alkyl group having up to 10 carbon atoms, and wherein at least one Rf is a halogenated alkoxy group.