Electrolyte for batteries and battery packs

• US 8,216,725 B2
• Filed: 01/13/2009
• Issued: 07/10/2012
• Est. Priority Date: 01/25/2008
• Status: Active Grant

• Current Assignee: BYD Company Limited
• Original Assignee: BYD Company Limited
• Inventors: Gao, Yi, Zhu, JiangMin
• Primary Examiner(s): WEINER, LAURA S
• Application Number:
  US12/352,981
• Publication Number:
  US 20090191455A1
• Time in Patent Office: 1,274 Days
• Field of Search: 429/327, 429/326, 429/200, 429/199, 429/307, 429/341, 429/339, 429/340, 429/343, 252/62.2
• US Class Current: 429/327
• 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 10/4235 Safety or regulating additives or arrangements in electrodes, separators or electrolyte H01M10/4242 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Electrolyte for lithium secondary batteries and battery packs includes a lithium salt, a non-aqueous solvent, and an additive. The additive includes two or more members selected from the group consisting of substances A, B and C, wherein A includes one or more fused ring compounds and fused heterocyclic compounds, B includes an alkoxy aromatic compound, and C includes halogenated borane-based salt.

Claims

1. An electrolyte for lithium-ion batteries, the electrolyte comprising:

a lithium salt;

a non-aqueous solvent; and

an additive, the additive including three members selected from each of substances A, B and C, wherein;

substance A includes one or more fused ring compounds and fused heterocyclic compounds;

substance B includes an alkoxy aromatic compound;

substance C includes halogenated borane-based salt; and

a weight ratio of substances A;

B;

C ranges from about 1;

0.05;

0.05 to about 1;

15;

15.

2. The electrolyte of claim 1, wherein weight ratio of the fused ring compounds to the fused heterocyclic compounds of substance A can range from about 1:

5 to about 10;

1.

3. The electrolyte of claim 1, wherein the fused ring compounds of substance A include one or more members selected from chemical structures (1) and (2), and the fused heterocyclic compounds of substance A include one or more members selected from chemical structures (3), (4) and (5);

and

4. The electrolyte of claim 1, wherein the alkoxy aromatic compounds of substance B include one or more members selected from chemical structures (6), (7) and (8);

and

5. The electrolyte of claim 1, wherein the halogenated borane-based salt includes Li₂B₁₂F_mH_12-m, wherein 12≦

m≦

1.

6. The electrolyte of claim 1, wherein the amount of additive can be about 1 to 20% of the electrolyte by weight.

7. The electrolyte of claim 1, wherein the lithium salt includes one or more members of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium perchlorate, lithium trifluoromethylsulfonate, lithium perfluorobutane sulfonate, lithium aluminate, lithium chloroaluminate, fluorinated lithium sulfonimide, lithium chloride and lithium iodide.

8. The electrolyte of claim 1, wherein the non-aqueous solvent include one or more members of gamma-butyrolactone, methyl ethyl carbonate, methyl propyl carbonate, dipropyl carbonate, anhydride, N-methyl pyrrolidone, N-dimethylformamide, N-methyl acetamide, acetonitrile, N,N-dimethylformamide, sulfolane, dimethyl sulfoxide, diethyl sulfite, and other unsaturated cyclic organic esters having fluorine and sulfur.

9. A lithium-ion battery comprising the electrolyte of claim 1.

10. A battery pack comprising a plurality of single lithium-ion batteries coupled in series or parallel, each lithium-ion battery comprising the electrolyte of claim 1.

11. An electrolyte for lithium-ion batteries, the electrolyte comprising:

a lithium salt;

a non-aqueous solvent; and

an additive, the additive including three members selected from each of substances A, B and C, wherein;

substance A includes one or more fused ring compounds and fused heterocyclic compounds, wherein the fused ring compounds include one or more members selected from chemical structures (1) and (2) and the fused heterocyclic compounds include one or more members selected from chemical structures (3), (4) and (5); and

12. The electrolyte of claim 11, wherein weight ratio of the fused ring compounds to the fused heterocyclic compounds of substance A can range from about 1:

5 to about 10;

1.

13. The electrolyte of claim 11, wherein the amount of additive can be about 1 to 20% of the electrolyte by weight.

14. A lithium-ion battery comprising the electrolyte of claim 11.

15. A battery pack comprising a plurality of single lithium-ion batteries coupled in series or parallel, each lithium-ion battery comprising the electrolyte of claim 11.

16. An electrolyte for lithium-ion batteries, the electrolyte comprising:

a lithium salt selected from one or more members consisting of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium perchlorate, lithium trifluoromethylsulfonate, lithium perfluorobutane sulfonate, lithium aluminate, lithium chloroaluminate, fluorinated lithium sulfonimide, lithium chloride and lithium iodide;

a non-aqueous solvent selected from one or more members consisting of gamma-butyrolactone, methyl ethyl carbonate, methyl propyl carbonate, dipropyl carbonate, anhydride, N-methyl pyrrolidone, N-dimethylformamide, N-methyl acetamide, acetonitrile, N,N-dimethylformamide, sulfolane, dimethyl sulfoxide, diethyl sulfite, and other unsaturated cyclic organic esters having fluorine and sulfur; and

an additive being about 1 to 20% of the electrolyte by weight, the additive including three members selected from each of substances A, B and C, wherein;

substance A includes one or more fused ring compounds and fused heterocyclic compounds, wherein the fused ring compounds include one or more members selected from chemical structures (1) and (2) and the fused heterocyclic compounds include one or more members selected from chemical structures (3), (4) and (5); and