Electrolyte additives for lithium-ion batteries

Patent metadata

Field	Value
Publication number	US-9257719-B1
Application number	US-50223409-A
Country	US
Kind code	B1
Filing date	Jul 14, 2009
Priority date	Jul 14, 2009
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

This invention employs a diamine electrolyte additive that enhances performance of lithium-ion batteries both at high and low temperatures, thereby minimizing the conventional performance gap across a wide temperature range, such as −30° C. to 60° C. At low temperatures, diamine additives can enhances cycling kinetics. At high temperatures, diamine additives can minimize capacity fading. In some variations, a lithium-ion battery electrolyte composition comprises a non-aqueous solvent, a lithium salt soluble in the non-aqueous solvent, and a diamine additive having the formula H 2 N—R—NH 2 , wherein R is an organic group such as (—CH 2 —) n , n=2-12.

First claim

What is claimed is:

1. A lithium-ion battery electrolyte composition consisting essentially of a non-aqueous solvent, a lithium salt soluble in said non-aqueous solvent, and one or more diamine additives having the formula H 2 N—R—NH 2 , wherein R is a saturated aliphatic chain organic group, having from 1 to 20 carbon atoms, wherein said diamine additive is soluble in said electrolyte composition, and wherein said diamine additive is present in an amount from 1 wt % to 10 wt %.

2. The electrolyte composition of claim 1 , wherein R is —(CH 2 ) n — and wherein n is selected from 1 to 20.

3. The electrolyte composition of claim 2 , wherein n is selected from 2 to 12.

4. The electrolyte composition of claim 3 , wherein n is selected from 2 to 6.

5. The electrolyte composition of claim 4 , wherein said diamine additive is ethylene diamine.

6. The electrolyte composition of claim 1 , wherein R is linear.

7. A lithium-ion battery comprising:
(a) an anode capable of reversibly absorbing and releasing lithium ions;
(b) a cathode capable of reversibly absorbing and releasing lithium ions; and
(c) an electrolyte consisting essentially of a non-aqueous solvent, a lithium salt soluble in said non-aqueous solvent, and at least one diamine additive having the formula H 2 N—R—NH 2 , wherein R is a saturated aliphatic chain organic group, having from 1 to 20 carbon atoms, wherein said diamine additive is soluble in said electrolyte, and wherein said diamine additive is present in an amount from 1 wt % to 10 wt %,
wherein the presence of said diamine additive that is soluble in said electrolyte increases the battery cycling stability of said lithium-ion battery, and
wherein the surfaces of said anode and said cathode are free of precipitated diamine additive.

8. The battery of claim 7 , wherein R is —(CH 2 ) n — and wherein n is selected from 1 to 20.

9. The battery of claim 8 , wherein n is selected from 2 to 12.

10. The battery of claim 9 , wherein said diamine additive is ethylene diamine.

11. The battery of claim 7 , wherein said anode comprises a material selected from the group consisting of carbon, lithium metal, lithiated oxide, and combinations of the foregoing.

12. The battery of claim 7 , wherein said cathode comprises a lithium transition-metal oxide.

13. The battery of claim 7 , wherein the presence of said diamine additive increases the battery discharge capacity of said lithium-ion battery.

14. The battery of claim 7 , wherein said battery cycling stability is measured at about 45° C. over at least 10 charge/discharge cycles.

15. The battery of claim 7 , wherein said battery cycling stability is measured at about 0° C. over at least 10 charge/discharge cycles.

16. A lithium-ion battery comprising an anode and a cathode, each capable of reversibly absorbing and releasing lithium ions; said battery further comprising an electrolyte consisting essentially of a non-aqueous solvent, a lithium salt soluble in said non-aqueous solvent, and ethylene diamine in an amount from 1 wt % to 10 wt % based on said electrolyte, wherein said ethylene diamine is soluble in said electrolyte, and wherein the surfaces of said anode and said cathode are free of precipitated ethylene diamine.

Assignees

• Liu Ping
• Sherman Elena
• Wang John
• Hrl Lab Llc

Inventors

• Liu Ping
• Sherman Elena
• Wang John

Classifications

• Y02E60/122

  Cross-Sectional Technologies · mapped topic

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M10/0567 Primary

  characterised by the additives · CPC title

• H01M4/133

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title