Redox shuttle for rechargeable lithium-ion cell

• US 20050221196A1
• Filed: 03/31/2005
• Published: 10/06/2005
• Est. Priority Date: 04/01/2004
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Chen, Jun, Dahn, Jeffrey R., Buhrmester, Claudia
• Granted Patent: US 7,811,710 B2
• Time in Patent Office: Days
• US Class Current: 429/324
• 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 10/4235 Safety or regulating additives or arrangements in electrodes, separators or electrolyte H01M10/4242 takes precedence
• CPC Class Codes: H01M 2004/028 Positive electrodes
• CPC Class Codes: H01M 2300/0042 Four or more solvents
• CPC Class Codes: H01M 4/00 Electrodes
• 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 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/136 Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• 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 4/485 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 4/5825 Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 6/168 by additives
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A redox chemical shuttle comprising an aromatic compound substituted with at least one tertiary carbon organic group and at least one alkoxy group (for example, 2,5-di-tert-butyl-1,4-dimethoxybenzene) provides repeated overcharge protection in rechargeable lithium-ion cells.

Claims

1. A lithium ion cell electrolyte comprising a charge carrying medium, lithium salt and cyclable redox chemical shuttle comprising an aromatic compound substituted with at least one tertiary carbon organic group and at least one alkoxy group.

2. An electrolyte according to claim 1 wherein the charge carrying medium comprises ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, dimethoxyethane or combination thereof and the lithium salt comprises LiPF₆, lithium bis(oxalato)borate or combination thereof.

3. An electrolyte according to claim 1 wherein the aromatic compound has a single organic ring.

4. An electrolyte according to claim 1 wherein the aromatic compound is substituted with two tertiary carbon groups, each tertiary carbon group independently having up to 12 carbon atoms.

5. An electrolyte according to claim 1 wherein the tertiary carbon group is tert-butyl.

6. An electrolyte according to claim 1 wherein the aromatic compound is substituted with two alkoxy groups, each alkoxy group independently having up to 10 carbon atoms.

7. An electrolyte according to claim 1 wherein the aromatic compound comprises 2,5-di-tert-butyl- 1 ,4-dimethoxybenzene.

8. An electrolyte according to claim 1 wherein the redox chemical shuttle has an electrochemical potential from about 3.7 to about 4.7 V vs. Li/Li⁺.

9. An electrolyte according to claim 1 wherein the redox chemical shuttle can provide overcharge protection in a lithium-ion cell after at least 20 charge-discharge cycles at a charging voltage sufficient to oxidize the shuttle to its radical cation and an overcharge charge flow equivalent to 100% of the cell capacity during each cycle.

10. An electrolyte according to claim 1 wherein the redox chemical shuttle can provide overcharge protection in a lithium-ion cell after at least 100 charge-discharge cycles at a charging voltage sufficient to oxidize the shuttle to its radical cation and an overcharge charge flow equivalent to 100% of the cell capacity during each cycle.

11. A rechargeable lithium-ion cell comprising a negative electrode;

positive electrode; and

an electrolyte comprising charge carrying medium, lithium salt and cyclable redox chemical shuttle comprising an aromatic compound substituted with at least one tertiary carbon organic group and at least one alkoxy group and having an electrochemical potential vs. Li/Li⁺ that is greater than that of the positive electrode material.

12. A rechargeable lithium-ion cell according to claim 11 wherein the negative electrode comprises graphite or Li_4/3Ti_5/3O₄ and the positive electrode comprises LiFePO₄, LiMnPO₄ or LiMn₂O₄.

13. A rechargeable lithium-ion cell according to claim 11 wherein the aromatic compound has a single organic ring.

14. A rechargeable lithium-ion cell according to claim 11 wherein the aromatic compound is substituted with at least two tertiary carbon groups and at least two alkoxy groups, each tertiary carbon group independently having up to 12 carbon atoms and each alkoxy group independently having up to 10 carbon atoms.

15. A rechargeable lithium-ion cell according to claim 11 wherein the aromatic compound comprises 2-tert-butyl-anisole, 3-tert-butyl-anisole, 4-tert-butyl-anisole, 1-nitro-3-tert-butyl-2-methoxybenzene, 1-cyano-3-tert-butyl-2-methoxybenzene, 1,4-di-tert-butyl-2-methoxybenzene, 5-tert-butyl-1,3-dinitro-2-methoxybenzene, 1,3,5-tri-tert-butyl-2-methoxybenzene, 2-tert-pentyl-anisole, 2-tert-butyl-1,4-dimethoxybenzene, 2,3-di-tert-butyl-1,4-dimethoxybenzene, 2,5-di-tert-butyl-1,4-dimethoxybenzene, 2,5-di-tert-pentyl-1,4-dimethoxybenzene, 2,5-di-tert-butyl-3,6-di-nitro-1,4-dimethoxybenzene, 2,5-di-tert-butyl-3,6-di-cyano-1,4-dimethoxybenzene, 2,5-di-tert-butyl-1,4-diethoxybenzene, 4-tert-butyl-1,2-dimethoxybenzene, 4,5-di-tert-butyl-1,2-dimethoxybenzene, 4,5-di-tert-pentyl-1,2-dimethoxybenzene, 4,5-di-tert-butyl-1,2-diethoxybenzene or 4,8-di-tert-butyl-1,5-dimethoxynaphthalene.

16. A rechargeable lithium-ion cell according to claim 11 wherein the aromatic compound comprises 2,5-di-tert-butyl-1,4-dimethoxybenzene.

17. A rechargeable lithium-ion cell according to claim 11 wherein the positive electrode has a recharge plateau and the redox chemical shuttle has a redox potential about 0.3 to about 0.6 V above the positive electrode recharge plateau.

18. A rechargeable lithium-ion cell according to claim 11 wherein the redox chemical shuttle can provide overcharge protection in a lithium-ion cell after at least 100 charge-discharge cycles at a charging voltage sufficient to oxidize the shuttle to its radical cation and an overcharge charge flow equivalent to 100% of the cell capacity during each cycle.

19. An electrical or electronic device comprising a rechargeable lithium-ion cell according to claim 11 without electronic overcharge protection circuitry.

20. A rechargeable lithium-ion cell comprising a negative electrode, positive electrode comprising LiFePO₄, electrolyte and a cyclable redox chemical shuttle comprising an aromatic compound substituted with at least one tertiary carbon organic group and at least one alkoxy group and having an electrochemical potential vs. Li/Li⁺ that is greater than that of LiFePO₄.

21. A rechargeable lithium-ion cell according to claim 20 wherein the positive electrode has a recharge plateau and the redox chemical shuttle has a redox potential about 0.3 to about 0.6 V above the positive electrode recharge plateau.

22. A rechargeable lithium-ion cell according to claim 20 wherein the redox chemical shuttle comprises 2,5-di-tert-butyl-1,4-dimethoxybenzene.