Functional electrolyte for lithium-ion batteries
Functional electrolyte solvents include compounds having at least one aromatic ring with 2, 3, 4 or 5 substituents, at least one of which is a substituted or unsubstituted methoxy group, at least one of which is a tert-butyl group and at least one of which is a substituted or unsubstituted polyether or poly(ethylene oxide) (PEO) group bonded through oxygen to the aromatic ring, are provided.
1. A functional electrolyte solvent comprising a compound of formula
wherein:
R 2 is H, F, Cl, Br, I, alkyl, or a polyether group; and
R 3 is H, F, Cl, Br, I, alkyl, or a polyether group.
2. The functional electrolyte solvent of claim 1 , wherein the compound has the structure
3. The functional electrolyte solvent of claim 1 , wherein the compound has the structure:
4. The functional electrolyte solvent of claim 1 , wherein the compound is:
5. The functional electrolyte solvent of claim 1 , wherein the compound is:
6. An electrolyte comprising:
the functional electrolyte solvent of claim 1 ; and
an alkali metal salt.
7. The electrolyte of claim 6 , wherein the functional electrolyte solvent is a redox active material and has a redox potential of 3 to 5 V.
8. The electrolyte if claim 6 , wherein the functional electrolyte solvent is 1-methoxy-4-(2-methoxyethoxy)-2,5-di-tert-butyl-benzene, 1-methoxy-4-[2-(2-methoxyethoxyl)ethoxy]-2,5-di-tert-butyl-benzene, or a mixture thereof.
9. The electrolyte of claim 6 , wherein the concentration of the functional electrolyte solvent in the electrolyte is from 0.0005 wt % and 60 wt %.
10. The electrolyte of claim 6 , wherein the alkali metal salt is a lithium salt.
11. The electrolyte of claim 6 , wherein the alkali metal salt is Li[(C 2 O 4 ) 2 B], Li(C 2 O 4 )BF 2 , LiClO 4 , LiBF 4 , LiAsF 6 , LiPF 6 , LiCF 3 SO 3 , Li(CF 3 SO 2 )2N, Li(CF 3 SO 2 ) 3 C, LiN(SO 2 C 2 F 5 ) 2 , lithium alkyl fluorophosphates, or a mixture of any two or more thereof.
12. The electrolyte of claim 6 further comprising a polar aprotic solvent.
13. The electrolyte of claim 12 , wherein the polar aprotic solvent is selected from ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, dimethyl ether, gamma butyrolactone, or a mixture of any two or more thereof.
14. The electrolyte of claim 6 , wherein the alkali metal salt is other than Li[(C 2 O 4 ) 2 B], Li(C 2 O 4 )BF 2 , and the electrolyte further comprises about 0.001 wt % to about 8 wt % of an electrode stabilizing additive that is Li[(C 2 O 4 ) 2 B], Li(C 2 O 4 )BF 2 , or a mixture thereof.
15. The electrolyte of claim 6 further comprising an electrode stabilizing additive that is a substituted or unsubstituted spirocyclic hydrocarbon containing at least one oxygen atom and at least one alkenyl or alkynyl group.
16. An electrochemical device comprising:
a cathode
an anode; and
an electrolyte of claim 6 .
17. The electrochemical device of claim 16 , wherein the device is a lithium secondary battery; the cathode is a lithium metal oxide cathode; the anode is a carbon or lithium metal anode; and the anode and cathode are separated from each other by a porous separator.
18. An electrolyte comprising:
an alkali metal salt; and
at least one of 1-methoxy-4-(2-methoxyethoxy)-2,5-di-tert-butyl-benzene, 1-methoxy-4-[2-(2-methoxyethoxyl)ethoxy]-2,5-di-tert-butyl-benzene, 1-methoxy-4-[2-[2-(2-ethoxyethoxyl)ethoxy]ethoxy]-2,5-di-tert-butyl-benzene, 1-methoxy-4-[2-[2-[2-(2-methoxyethoxyl)ethoxy]ethoxy]ethoxy]-2,5-di-tert-butyl-benzene, 1-methoxy-4-[2-[2-[2-[2-(2-methoxyethoxyl)ethoxy]ethoxy]ethoxy]ethoxy]-2,5-di-tert-butyl-benzene, and 1-methoxy-4-[2-[2-[2-[2-[2-(2-methoxyethoxyl)ethoxy]ethoxy]ethoxy]ethoxy]ethoxyl-2,5-di-tert-butyl-benzene.