Substituted phenothiazine redox shuttles for rechargeable lithium-ion cell

• US 7,615,312 B2
• Filed: 05/17/2005
• Issued: 11/10/2009
• Est. Priority Date: 05/17/2005
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Lamanna, William M., Dahn, Jeffrey R., Buhrmester, Claudia, Wang, Richard L.
• Primary Examiner(s): Weiner; Laura S
• Application Number:
  US11/130,850
• Publication Number:
  US 20060263697A1
• Time in Patent Office: 1,638 Days
• Field of Search: 429/328, 429/336, 429/330, 429/332, 429/338, 429/342, 429/339, 429/340, 429/231.95, 429/231.1, 429/221, 429/224, 429/50, 296/232, 296/231
• US Class Current: 429/231.1
• 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 2300/0042 Four or more solvents
• 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 4/485 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: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y10T 29/49108 Electric battery cell making
• CPC Class Codes: Y10T 29/4911 including sealing

Abstract

A rechargeable lithium-ion cell contains a positive electrode, negative electrode, charge-carrying electrolyte containing charge carrying medium and lithium salt, and an N-substituted or C-substituted phenothiazine compound dissolved in or dissolvable in the electrolyte. The substituted phenothiazine compound has an oxidation potential above the positive electrode recharged potential and serves as a cyclable redox chemical shuttle providing cell overcharge protection.

Claims

1. A rechargeable lithium-ion cell comprising:

(a) a positive electrode having a recharged potential and comprising LiFePO₄, Li₂FeSiO₄, Li_xMnO₂ (where x is about 0.3 to about 0.4), or MnO₂;

(b) a negative electrode;

(c) a charge-carrying electrolyte comprising a charge carrying medium comprising a charge carrying medium that includes an organic carbonate and a lithium salt; and

(d) a cyclable redox chemical shuttle comprising 10-methyl-phenothiazine, 10-ethyl-phenothiazine, 3-chloro-10-ethyl-phenothiazine, 10-isopropyl-phenothiazine, 2-perfluoromethyl-phenothiazine, 10-acetyl-phenothiazine 2-cyano-10-perfluoromethylsulfonyl-phenothiazine, 2-methoxy-10-perfluoromethylsulfonyl-phenothiazine, 2-perfluoromethyl-10-perfluoromethylsulfonyl-phenothiazine, 10-perfluoromethyl-phenothiazine, 10-perfluoromethylsulfonyl-phenothiazine, 10-(1,1,1,2,3,3)-hexafluoropropyl-phenothiazine, or mixtures thereof, wherein

the recharged potential is the potential at which the positive electrode becomes delithiated during the first charge cycle to a lithium level corresponding to at least 90% of the available recharged cell capacity.

2. A cell according to claim 1 wherein the chemical redox shuttle is substituted at its nitrogen atom.

3. A cell according to claim 1 wherein the chemical redox shuttle is substituted at one or more ring carbon atoms.

4. A cell according to claim 3 wherein the chemical redox shuttle is 2-perfluoromethyl-phenothiazine.

5. A cell according to claim 1 wherein the chemical redox shuttle is substituted with one or more alkyl groups containing 1 to about 4 carbon atoms.

6. A cell according to claim 1 wherein the chemical redox shuttle comprises 10-methyl-phenothiazine, 10-ethyl-phenothiazine, 3-chloro-10-ethyl-phenothiazine, 10-isopropyl-phenothiazine, 10-acetyl-phenothiazine, or mixtures thereof.

7. A cell according to claim 1 wherein the chemical redox shuttle comprises 2-cyano-10-perfluoromethylsulfonyl-phenothiazine, 2-methoxy-10-perfluoromethylsulfonyl-phenothiazine, 2-perfluoromethyl-10-perfluoromethylsulfonyl-phenothiazine, 10-perfluoromethyl-phenothiazine, 10-perfluoromethylsulfonyl-phenothiazine, 10-(1,1,1,2,3,3)-hexafluoropropyl-phenothiazine, or mixtures thereof.

8. A cell according to claim 1 wherein the cyclable redox chemical shuttle is present in the electrolyte in an amount of from 0.1M to about 0.3M.

9. A cell according to claim 1 wherein the electrolyte comprises a cosolvent.

10. A cell according to claim 1 wherein the chemical redox shuttle has an oxidation potential from about 0.3 V to about 5 V above the recharged potential of the positive electrode.

11. A cell according to claim 1 wherein the chemical redox shuttle has an oxidation potential from about 0.3 to about 0.6 V above the recharged potential of the positive electrode.

12. A cell according to claim 1 wherein the chemical redox shuttle provides overcharge protection after at least 30 charge-discharge cycles at a charging voltage sufficient to oxidize the phenothiazine compound and at an overcharge charge flow equivalent to 100% of the cell capacity during each cycle.

13. A cell according to claim 1 wherein the chemical redox shuttle provides overcharge protection after at least 80 charge-discharge cycles at a charging voltage sufficient to oxidize the phenothiazine compound and at an overcharge charge flow equivalent to 100% of the cell capacity during each cycle.

14. A cell according to claim 1 wherein the negative electrode comprises graphitic carbon, lithium metal, or a lithium alloy.

15. A cell according to claim 1 wherein the charge carrying medium comprises ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, or combinations thereof.

16. A rechargeable lithium-ion cell comprising:

(a) a positive electrode having a recharged potential and comprising LiFePO₄, Li₂FeSiO₄, Li_xMnO₂ (where x is about 0.3 to about 0.4) or MnO₂;

(b) a negative electrode comprising graphitic carbon, lithium metal or a lithium alloy; and

(c) a charge-carrying electrolyte comprising;

(i) a charge-carrying media comprising ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate or combination thereof;

(ii) a lithium salt comprising LiPF₆, lithium bis(oxalato)borate, or combination thereof; and

(iii) a cyclable redox chemical shuttle comprising 10-methyl-phenothiazine, 10-ethyl-phenothiazine, 3-chloro-10-ethyl-phenothiazine, 10-acetyl-phenothiazine, or mixtures thereof dissolved in the electrolyte and having an oxidation potential above the recharged potential of the positive electrode.

17. A method for manufacturing a rechargeable lithium-ion sealed cell comprising the steps of assembling in any order and enclosing in a suitable case:

(a) a positive electrode having a recharged potential and comprising LiFePO₄, Li₂FeSiO₄, Li_xMnO₂ (where x is about 0.3 to about 0.4), or MnO₂;

(b) a negative electrode;

(c) a charge-carrying electrolyte comprising charge carrying medium and lithium salt; and

(d) a cyclable redox chemical shuttle comprising 10-methyl-phenothiazine, 10-ethyl-phenothiazine, 3-chloro-10-ethyl-phenothiazine, 10-isopropyl-phenothiazine, 2-perfluoromethyl-phenothiazine, 10-acetyl-phenothiazine 2-cyano-10-perfluoromethylsulfonyl-phenothiazine, 2-methoxy-10-perfluoromethylsulfonyl-phenothiazine, 2-perfluoromethyl-10-perfluoromethylsulfonyl-phenothiazine, 10-perfluoromethyl-phenothiazine, 10-perfluoromethylsulfonyl-phenothiazine, 10-(1,1,1,2,3,3)-hexafluoropropyl-phenothiazine, or mixtures thereof, wherein

the recharged potential is the potential at which the positive electrode becomes delithiated during the first charge cycle to a lithium level corresponding to at least 90% of the available recharged cell capacity.