Surface stabilized electrodes for lithium batteries

• US 20070281212A1
• Filed: 05/30/2007
• Published: 12/06/2007
• Est. Priority Date: 05/31/2006
• Status: Active Grant

• Current Assignee: UChicago Argonne LLC
• Original Assignee: UChicago Argonne LLC
• Inventors: Johnson, Christopher S., Thackeray, Michael M., Kang, Sun-Ho
• Granted Patent: US 8,148,011 B2
• Time in Patent Office: Days
• US Class Current: 429/231.100
• CPC Class Codes: C01G 45/125 of the type[MnO3]n-, e.g. Li2MnO3, Li2[MxMn1-xO3], (La,Sr)MnO3
• CPC Class Codes: C01G 51/50 of the type [MnO2]n- , e.g. Li(CoxMn1-x)O2, Li(MyCoxMn1-x-y)O2
• CPC Class Codes: C01G 53/50 of the type [MnO2]n- , e.g. Li(NixMn1-x)O2, Li(MyNixMn1-x-y)O2
• CPC Class Codes: C01P 2002/32 spinel-type (AB2O4)
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2004/80 Particles consisting of a mixture of two or more inorganic phases
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0567 characterised by the additives
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/1391 of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/364 as mixtures
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• 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: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

An uncycled, preconditioned positive metal-oxide or lithium-metal-oxide electrode for a non-aqueous lithium electrochemical cell, the electrode being preconditioned in an aqueous or a non-aqueous solution containing stabilizing cations and anions that are etched into the electrode surface to form a protective layer. Methods of preconditioning the electrodes are disclosed as are electrochemical cells and batteries containing the electrodes.

Claims

1. A stabilized metal oxide or lithium-metal-oxide electrode, including a cathode and/or an anode for a non-aqueous lithium electrochemical cell and/or battery, said electrode having an acid-etched surface containing stabilizing anions and/or cations, said stabilizing cations being selected from one or more of ammonium, phosphorus, titanium, silicon, zirconium, aluminum and boron cations and said stabilizing anions being fluoride anions.

2. The stabilized electrode of claim 1, wherein said stabilizing cations are selected from one or more of phosphorus, aluminum and boron.

3. The stabilized electrode of claim 1, wherein said electrode has the general formula of xLi₂M′

O₃.(1−

x)LiMO₂ in which M′

is one or more metal ions with an average tetravalent oxidation state and 0≦

x<

1, and in which M is one or more metal ions with an average trivalent oxidation state.

4. The stabilized electrode of claim 3, wherein M′

is selected from Mn, Ti, and Zr and M is selected from Mg, Al, Ti, V, Cr, Mn, Fe, Co, and Ni.

5. The stabilized electrode of claim 4, wherein M′

is Mn, and M is selected from Mn, Co and Ni.

6. The stabilized electrode of claim 1, wherein said electrode has the general formula of xLi₂M′

O₃.(1−

x)LiM₂O₄ (0≦

x<

1) and M′

is one or more metal ions with an average tetravalent oxidation state and M is one or more metal cations with an average oxidation state of 3.5.

7. The stabilized electrode of claim 1, wherein said electrode is selected from V₂O₅-containing or MnO₂-containing compounds.

16. A non-aqueous lithium electrochemical cell comprising an anode, an electrolyte and the cathode, wherein one or both of the anode and cathode are according to claim 1.

17. A non-aqueous lithium battery comprising a plurality of electrochemical cells, electrically connected, each cell comprising an, an electrolyte and a cathode, wherein one or both of the anode and cathode are according to claim 1.

8. A method of stabilizing a metal oxide or lithium-metal-oxide electrode by contacting the electrode prior to cell assembly with an aqueous or a non-aqueous acid solution with a pH greater than 4 but less than 7 containing stabilizing cations selected from ammonium, phosphorus, titanium, silicon, zirconium, aluminum and boron and/or fluoride anions for a time and at a temperature sufficient to etch the electrode.

9. The method of claim 8, wherein the pH of the aqueous or non-aqueous acid solution is greater than 6 but less than 7.

10. The method of claim 8, wherein the stabilizing cations and anions are derived from aqueous or non-aqueous solutions of NH₄ PF₆, (NH₄)₂TiF₆, (NH₄)₂SiF₆, (NH₄)₂ZrF₆, (NH₄)₃AlF₆, NH₄BF₄.

11. The method of claim 8, wherein the non-aqueous acid solution is an alcohol.

12. The method of claim 11, wherein the non-aqueous acid solution is methanol.

13. A stabilized electrode made according to the method of claim 8.

14. A method of stabilizing a metal-oxide or lithium-metal-oxide electrode by preconditioning the electrode in situ within a non-aqueous lithium cell by dissolving one or more salts selected from NH₄PF₆, (NH₄)₂TiF₆, (NH₄)₂SiF₆, (NH₄)₂ZrF₆, (NH₄)₃AlF₆, NH₄BF₄ in the electrolyte prior to cell assembly and thereafter cycling the electrode.

15. A stabilized electrode made according to the method of claim 14.