Long life lithium batteries with stabilized electrodes

• US 7,968,235 B2
• Filed: 05/28/2004
• Issued: 06/28/2011
• Est. Priority Date: 07/17/2003
• Status: Active Grant

• Current Assignee: U Chicago Argonne, LLC
• Original Assignee: UChicago Argonne LLC
• Inventors: Kim, Jaekook, Vissers, Donald R., Amine, Khalil
• Primary Examiner(s): CONLEY, OI K
• Assistant Examiner(s): Ryan; Patrick
• Application Number:
  US10/857,365
• Publication Number:
  US 20050019670A1
• Time in Patent Office: 2,587 Days
• Field of Search: 429/188, 429/324, 429/322, 429/121, 429/321, 429/330, 429/337, 429/338
• US Class Current: 429/322
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0567 characterised by the additives
• CPC Class Codes: H01M 10/0568 characterised by the solutes
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 6/166 by the solute
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The present invention relates to non-aqueous electrolytes having stabilization additives and electrochemical devices containing the same. Thus the present invention provides electrolytes containing an alkali metal salt, a polar aprotic solvent, a first additive that is a substituted or unsubstituted organoamine, substituted or unsubstituted alkane, substituted or unsubstituted alkene, or substituted or unsubstituted aryl compound, and/or a second additive that is a metal(chelato)borate. When used in electrochemical devices with, e.g., lithium manganese oxide spinel electrodes, the new electrolytes provide batteries with improved calendar and cycle life.

Claims

1. A non-aqueous electrolyte comprising:

lithium salt;

a polar aprotic solvent comprising ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, dimethyl ether, or gamma butyrolactone;

a first additive comprises a vinyl pyridine; and

a second additive that is Li(C₂O₄)BF₂ .

2. The non-aqueous electrolyte of claim 1 wherein the vinyl pyridine is 2-vinyl pyridine or 4-vinyl pyridine.

3. The non-aqueous electrolyte of claim 1 wherein the lithium salt is LiClO₄, LiBF₄, LiAsF₆, LiPF₆, LiCF₃SO₃, Li(CF₃SO₂)₂N, Li(CF₃SO₂)₃C, LiN(SO₂C₂F₅)₂, lithium alkyl fluorophosphates, or a mixture of any two or more thereof.

4. An electrochemical device comprising:

a cathode;

an anode; and

the non-aqueous electrolyte of claim 1.

5. The electrochemical device of claim 4 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.

6. The electrochemical device of claim 5 wherein the cathode comprises LiCoO₂, LiNiO₂, LiNi₁₋

x,Co_yMet_zO₂, LiMn_0.5Ni_0.5O₂, LiMn_0.3Co_0.3Ni_0.3O₂, LiFePO₄, LiMn₂O₄, LiFeO₂, LiMet_0.5Mn_1.5O₄, vanadium oxide, or mixtures of any two or more thereof, wherein Met is Al, Mg, Ti, B, Ga, Si, Ni, or Co, and wherein 0<

x<

0.3 , 0<

y <

0.5, and 0<

z<

0.5.

7. The electrochemical device of claim 5 wherein the cathode comprises a spinel manganese oxide with a formula of Li_1+xMn₂₋

zMet_yO<sub>4−

m</sub>X_n, wherein Met is Al, Mg, Ti, B, Ga, Si, Ni, or Co, and X is S or F, and wherein 0<

x<

0.3, 0<

y<

0.5, 0<

z<

0.5, 0<

m<

0.5 and 0<

n<

0.5.

8. The electrochemical device of claim 5 wherein the anode comprises graphite, carbon, Li₄Ti₅O₁₂, tin alloys, silica alloys, intermetallic compounds, lithium metal, or mixtures of any two or more thereof.

9. The electrochemical device according to claim 5 wherein the first additive and the second additive are independently present in an amount from about 0.0005 to about 30 wt %.

10. The electrochemical device according to claim 5 wherein the first additive is present in an amount from about 0.001 to about 10 wt %.

11. The electrochemical device of claim 5 wherein the first additive is present in an amount of about 0.01 to 2 wt %.

12. The electrochemical device of claim 5 wherein the second additive is present in an amount of about 0.001 to about 2 wt %.

13. A method of making the non-aqueous electrolyte of claim 1, the method comprising combining

the lithium salt;

the polar aprotic solvent;

the first additive; and

the second additive.