Electrode stabilizing materials

1. An electrolyte comprising:

a polar aprotic solvent;

an alkali metal salt; and

an electrode stabilizing compound comprising a monomeric compound, which when polymerized forms an electrically conductive polymer;

wherein:

the monomeric compound is represented by formula I:

R 1 , R 2 , R 3 , and R 4 are individually H, F, Cl, Br, I, an alkyl, an alkenyl, an alkynyl, an aryl, or a heteroaryl group;

at least one of R 1 , R 2 , R 3 , and R 4 is an unsubstituted alkyl, an alkenyl, or an alkynyl group; and

at least one of R 1 , R 2 , R 3 , and R 4 is a C 4 -C 8 alkyl.

2. The electrolyte of claim 1 , wherein at least one of R 1 , R 2 , R 3 , and R 4 is a C 1 -C 12 alkyl.

3. The electrolyte of claim 1 , wherein at least one of R 2 and R 3 is a C 1 -C 12 alkyl.

4. The electrolyte of claim 1 , wherein R 2 or R 3 is pentyl, hexyl, or heptyl.

5. The electrolyte of claim 1 , wherein the electrode stabilizing compound is present from 0.01 wt % to 3 wt %.

6. The electrolyte of claim 1 , wherein the polar aprotic solvent comprises ethylene carbonate, propylene carbonate, dimethyl carbonate; ethyl methyl carbonate; diethyl carbonate; methyl propyl carbonate; ethyl propyl carbonate; dipropyl carbonate; bis(trifluoroethyl) carbonate; bis(pentafluoropropyl) carbonate; trifluoroethyl methyl carbonate; pentafluoroethyl methyl carbonate; heptafluoropropyl methyl carbonate; perfluorobutyl methyl carbonate; trifluoroethyl ethyl carbonate; pentafluoroethyl ethyl carbonate; heptafluoropropyl ethyl carbonate; perfluorobutyl ethyl carbonate; fluorinated oligomers; dimethoxyethane; triglyme; dimethylvinylene carbonate; tetraethyleneglycol; dimethyl ether; polyethylene glycols; sulfones; or γ-butyrolactone.

7. The electrolyte of claim 1 , wherein the alkali metal salt comprises a lithium salt, a sodium salt, or a potassium salt.

8. The electrolyte of claim 1 , wherein the alkali metal salt comprises the lithium salt and the lithium salt comprises Li[B(C 2 O 4 ) 2 ]; Li[BF 2 (C 2 O 4 )]; LiClO 4 ; LiBF 4 ; LiAsF 6 ; LiSbF 6 ; LiBr, LiPF 6 ; Li[CF 3 SO 3 ]; Li[N(CF 3 SO 2 ) 2 ]; Li[C(CF 3 SO 2 ) 3 ]; Li[B(C 6 F 5 ) 4 ]; Li[B(C 6 H 5 ) 4 ]; Li[N(SO 2 CF 3 ) 2 ]; Li[N(SO 2 CF 2 CF 3 ) 2 ]; LiN(SO 2 C 2 F 5 ) 2 ; Li[BF 3 C 2 F 5 ]; and Li[PF 3 (CF 2 CF 3 ) 3 ]; or a lithium alkyl fluorophosphate.

9. An electrochemical device comprising:

an anode;

a cathode; and

an electrolyte comprising

a polar aprotic solvent;

an alkali metal salt; and

an electrode stabilizing compound comprising a monomeric compound, which when polymerized forms an electrically conductive polymer;

wherein:

the monomeric compound is represented by formula I:

R 1 , R 2 , R 3 , and R 4 are individually H, F, Cl, Br, I, an alkyl, an alkenyl, an alkynyl, an aryl, or a heteroaryl group;

at least one of R 1 , R 2 , R 3 , and R 4 is an alkyl, an alkenyl, or an alkynyl group; and

at least one of R 1 , R 2 , R 3 , and R 4 is a C 4 -C 8 alkyl.

10. The electrochemical device of claim 9 , wherein at least one of R 2 and R 3 is a C 1 -C 12 alkyl.

11. The electrochemical device of claim 9 , wherein R 2 or R 3 is pentyl, hexyl, or heptyl.

12. An electrolyte comprising:

a polar aprotic solvent;

an alkali metal salt; and

an electrode stabilizing compound comprising a monomeric compound, which when polymerized forms an electrically conductive polymer;

wherein:

the monomeric compound is represented by formula I:

R 1 , R 2 , R 3 , and R 4 are individually H, F, Cl, Br, I, an alkyl, an alkenyl, an alkynyl, an aryl, or a heteroaryl group;

at least one of R 1 , R 2 , R 3 , and R 4 is an unsubstituted alkyl, an alkenyl, or an alkynyl group; and

at least one of R 2 and R 3 is a C 1 -C 12 alkyl.

13. The electrolyte of claim 12 , wherein at least one of R 1 , R 2 , R 3 , and R 4 is a C 1 -C 12 alkyl.

14. The electrolyte of claim 12 , R 2 or R 3 is pentyl, hexyl, or heptyl.

15. The electrolyte of claim 12 , wherein the electrode stabilizing compound is present from 0.01 wt % to 3 wt %.

16. The electrolyte of claim 12 , wherein the polar aprotic solvent comprises ethylene carbonate, propylene carbonate, dimethyl carbonate; ethyl methyl carbonate; diethyl carbonate; methyl propyl carbonate; ethyl propyl carbonate; dipropyl carbonate; bis(trifluoroethyl) carbonate; bis(pentafluoropropyl) carbonate; trifluoroethyl methyl carbonate; pentafluoroethyl methyl carbonate; heptafluoropropyl methyl carbonate; perfluorobutyl methyl carbonate; trifluoroethyl ethyl carbonate; pentafluoroethyl ethyl carbonate; heptafluoropropyl ethyl carbonate; perfluorobutyl ethyl carbonate; fluorinated oligomers; dimethoxyethane; triglyme; dimethylvinylene carbonate; tetraethyleneglycol; dimethyl ether; polyethylene glycols; sulfones; or γ-butyrolactone.

17. The electrolyte of claim 12 , wherein the alkali metal salt comprises a lithium salt, a sodium salt, or a potassium salt.

18. The electrolyte of claim 12 , wherein the alkali metal salt comprises the lithium salt and the lithium salt comprises Li[B(C 2 O 4 ) 2 ]; Li[BF 2 (C 2 O 4 )]; LiClO 4 ; LiBF 4 ; LiAsF 6 ; LiSbF 6 ; LiBr, LiPF 6 ; Li[CF 3 SO 3 ]; Li[N(CF 3 SO 2 ) 2 ]; Li[C(CF 3 SO 2 ) 3 ]; Li[B(C 6 F 5 ) 4 ]; Li[B(C 6 H 5 ) 4 ]; Li[N(SO 2 CF 3 ) 2 ]; Li[N(SO 2 CF 2 CF 3 ) 2 ]; LiN(SO 2 C 2 F 5 ) 2 ; Li[BF 3 C 2 F 5 ]; and Li[PF 3 (CF 2 CF 3 ) 3 ]; or a lithium alkyl fluorophosphate.

19. An electrochemical device comprising:

an anode;

a cathode; and

an electrolyte comprising

a polar aprotic solvent;

an alkali metal salt; and

an electrode stabilizing compound comprising a monomeric compound, which when polymerized forms an electrically conductive polymer;

wherein:

the monomeric compound is represented by formula I:

R 1 , R 2 , R 3 , and R 4 are individually H, F, Cl, Br, I, an alkyl, an alkenyl, an alkynyl, an aryl, or a heteroaryl group;

at least one of R 1 , R 2 , R 3 , and R 4 is an alkyl, an alkenyl, or an alkynyl group; and

at least one of R 2 and R 3 is a C 1 -C 12 alkyl.

20. The electrochemical device of claim 19 , wherein R 2 or R 3 is pentyl, hexyl, or heptyl.