High energy electrochemical cell employing solid-state anode

• US 5,284,721 A
• Filed: 08/01/1990
• Issued: 02/08/1994
• Est. Priority Date: 08/01/1990
• Status: Expired due to Term

• Current Assignee: EnerSys Advanced Systems, Inc. (EnerSys)
• Original Assignee: Alliant Techsystems Incorporated (Northrop Grumman Corporation)
• Inventors: Beard, Kirby W.
• Primary Examiner(s): Bell, Mark L.
• Assistant Examiner(s): EINSMANN, MARGARET V
• Application Number:
  US07/561,132
• Time in Patent Office: 1,287 Days
• Field of Search: 429/194-198, 429/218
• US Class Current: 429/343
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0567 characterised by the additives
• CPC Class Codes: H01M 10/0568 characterised by the solutes
• CPC Class Codes: H01M 10/0569 characterised by the solvents
• CPC Class Codes: H01M 12/06 with one metallic and one gaseous electrode
• CPC Class Codes: H01M 4/36 Selection of substances as active materials, active masses, active liquids
• 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 4/581 Chalcogenides or intercalation compounds thereof
• CPC Class Codes: H01M 6/14 Cells with non-aqueous electrolyte
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Improved anodes having active materials consisting substantially of one or more lithium insertion compounds further consisting of transition metal chalcogenides or oxides capable of reversibly intercalating lithium ions are disclosed. Cells utilizing these anodes are also disclosed.

Claims

1. A high rate secondary electrochemical cell comprising:

an anode comprising a reversible lithium intercalation compound selected from one or more transition metal chalcogenides having a relatively high lithium intercalation ability and a relatively low molecular weight and having the general formula;

space="preserve" listing-type="equation">Li.sub.x M.sub.a X.sub.b,

where M is selected from transition metal(s);

X is selected from O, S, Se, and Te; and

where x, a and b are numbers representing relative combining ratios and wherein the intercalation compound has properties including a potential of no more than 1.5 V versus a lithium reference electrode and >

200 mAh/gm intercalation/deintercalation capacity (<

133 gm/Faraday);

a compatible cathode having a cathode active material and a current collector; and

an electrolyte system.

2. The electrochemical cell of claim 1 wherein M is selected from Sc, Ti, Y, Zr and combinations thereof.

3. The electrochemical cell of claim 2 wherein the cathode comprises an active metal material and a current collector and said electrolyte is an aqueous electrolyte.

4. The electrochemical cell of claim 1 wherein the cathode active material is selected from a group consisting of SO₂, SOCl₂, (CF)_n, FeS₂, CuF₂, PbI, M_n O₂, Bi₂ Pb₂ O₅, V₂ O₅ and the electrolyte selected from non-aqueous or aqueous electrolytes with or without co-solvents.

5. The electrochemical cell of claim 1 wherein the cathode further comprises at least a second reversible lithium intercalation compound selected from a group consisting of those compatible with the material of the anode and the electrolyte system is either non-aqueous or aqueous with or without co-solvents.

6. The electrochemical cell of claim 5 wherein the electrolyte system is a non-aqueous organic ester-based electrolyte solution containing an amount of a lithium salt and CO₂ additive.

7. The electrochemical cell of claim 5 wherein the intercalation compound of the anode and the cathode is the same varying in the degree of lithium intercalation such that the anode is Li-doped and the cathode is Li-depleted.

8. The electrochemical cell of claim 7 wherein the intercalation compound is selected from Li_x TiO₂, Li_x Ti₂ O₃ (where 0<

X≦

2.0) and mixtures thereof.

9. A non-aqueous electrochemical cell comprising:

an anode comprising a first reversible lithium intercalation compound or mixtures thereof selected from transition metal chalcogenides having a relatively high lithium intercalation ability and a relatively low molecular weight and having the general formula;

space="preserve" listing-type="equation">Li.sub.x M.sub.a X.sub.b,

where M is selected from transition metal(s);

X is selected from O, S, Se, and Te;

where x, a and b are numbers representing relative combining ratios and wherein the intercalation compound has properties including a potential of no more than 1.5 V versus a lithium reference electrode and >

200 mAh/gm intercalation/deintercalation capacity (<

133 gm/Faraday);

a cathode having a cathode active material comprising a second reversible lithium intercalation compound compatible with that of the anode; and

a non-aqueous electrolyte system.

10. The electrochemical cell claim 9 wherein M is selected from Sc, Ti, Y, Zr and combinations thereof.

11. The electrochemical cell of claim 9 wherein M is Ti and X is O.

12. The electrochemical cell of claim 9 wherein the first and the second intercalation compounds are the same, varying in degree of lithium intercalation between anode which is in an highly reducing oxidation state and the cathode which is an highly oxidizing oxidation state.

13. The electrochemical cell of claim 9 wherein the non-aqueous electrolyte system further comprises a solid-state electrolyte/separator.

14. The electrochemical cell of claim 9 wherein the electrolyte further comprises an amount of LiAsF₆ and an amount of LiBF₄.

15. The electrochemical cell of claim 14 wherein an amount of CO₂ additive is dissolved in the electrolyte and in equilibrium with the vapor phase.

16. A non-aqueous electrochemical cell comprising:

an anode comprising a first reversible lithium intercalation compound or mixtures thereof selected from transition metal chalcogenides having a relatively high lithium intercalation ability and a relatively low molecular weight and having the general formula;

space="preserve" listing-type="equation">Li.sub.x Ti.sub.a O.sub.b,

where 0.5≦

x ≦

2

a=1

b=1.5≦

b≦

3 and

wherein the intercalation compound has properties including a potential of no more than 1.5 V versus a lithium reference electrode and >

200 mAh/gm intercalation/deintercalation capacity (<

133 gm/Faraday);

a cathode having a cathode active material comprising a second reversible lithium intercalation compound compatible with that of the anode; and

a non-aqueous electrolyte system.

17. The electrochemical cell of claim 16 wherein the intercalation compound of the anode is selected from Li_x TiO₂ and Li_x Ti₂ O₃ and mixtures thereof and the cathode active intercalation material is Li_y CoO₂ wherein 0<

y≦

1.0.

18. The electrochemical cell of claim 17 wherein the electrolyte system is a non-aqueous organic ester-based electrolyte solution containing an amount of a lithium salt and CO₂ additive.