Lithium secondary battery including electrolyte containing monofluorosilane compound

Patent metadata

Field	Value
Publication number	US-11367902-B2
Application number	US-201916710135-A
Country	US
Kind code	B2
Filing date	Dec 11, 2019
Priority date	Jan 31, 2017
Publication date	Jun 21, 2022
Grant date	Jun 21, 2022

Abstract

A lithium secondary battery including a cathode; an anode; and an electrolyte disposed between the cathode and the anode,wherein the cathode includes a cathode active material represented by Formula 1,the electrolyte includes a lithium salt; a non-aqueous solvent; and a monofluorosilane compound represented by Formula 2,wherein an amount of the monofluorosilane compound is in a range of about 0.1 percent by weight (wt %) to about 5 wt % based on the total weight of the electrolytewherein, in Formula 1, 0.9≤x≤1.2, 0.85<y≤0.95, and 0≤z<0.2; M is aluminum, magnesium, manganese, cobalt, iron, chromium, vanadium, titanium, copper, boron, calcium, zinc, zirconium, niobium, molybdenum, strontium, antimony, tungsten, bismuth, or a combination thereof; A is an element having an oxidation number of −1 or −2, and R1 is a substituted or unsubstituted linear or branched C2-C30 alkyl group or a substituted or unsubstituted C6-C60 aryl group.

First claim

What is claimed is:

1. A lithium secondary battery comprising:
a cathode;
an anode comprising a carbonaceous anode active material; and
an electrolyte disposed between the cathode and the anode,
wherein the cathode comprises a cathode active material represented by Formula 3 or 4,
the electrolyte comprises a lithium salt; a non-aqueous solvent; and a monofluorosilane compound represented by Formula 2,
wherein an amount of the monofluorosilane compound is in a range of about 0.8 percent by weight to about 2 percent by weight, based on a total weight of the electrolyte
Li x Ni y′ Co 1−y′−z′ Al z′ O 2   Formula 3

Li x Ni y′ Co 1−y′−z′ Mn z′ O 2   Formula 4

wherein, in Formula3 and 4,
0.9≤x≤1.2, 0.85<y′<0.95, 0<z′<0.1, and 0<1−y′−z′<0.15, and
in Formula 2,
R 1 is a substituted or unsubstituted linear or branched C 2 -C 30 alkyl group or a substituted or unsubstituted C 6 -C 60 aryl group; and
R 2 and R 3 are each independently a substituted or unsubstituted linear or branched C 1 -C 30 alkyl group or a substituted or unsubstituted C 6 -C 60 aryl group,
wherein a substituent of the substituted C 1 -C 30 alkyl group or C 6 -C 60 aryl group is a halogen, a methyl group, an ethyl group, a propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a t-butyl group, a trifluoromethyl group, a tetrafluoroethyl group, a vinyl group, a propenyl group, a butenyl group, or a combination thereof.

2. The lithium secondary battery of claim 1 , wherein at least one of R 1 to R 3 is a substituted or unsubstituted C 6 -C 60 aryl group.

3. The lithium secondary battery of claim 1 , wherein R 1 to R 3 are each independently a substituted or unsubstituted linear or branched C 2 -C 30 alkyl group.

4. The lithium secondary battery of claim 1 , wherein the monofluorosilane compound is a compound represented by one of Formulae 2-1 to 2-12:

5. The lithium secondary battery of claim 1 , wherein the lithium salt is lithium difluoro(oxalate)borate, LiBF 4 , LiPF 6 , LiCF 3 SO 3 , (CF 3 SO 2 ) 2 NLi, (FSO 2 ) 2 NLi, or a combination thereof.

6. The lithium secondary battery of claim 5 ,
wherein the lithium salt comprises LiPF 6 and lithium difluoro(oxalate)borate, and
wherein an amount of the lithium difluoro(oxalate)borate is about 2 percent by weight or less, based on the total weight of the electrolyte.

7. The lithium secondary battery of claim 1 , wherein the non-aqueous solvent comprises fluoroethylene carbonate.

8. The lithium secondary battery of claim 7 , wherein an amount of the fluoroethylene carbonate is in a range of about 0.3 percent by weight to about 20 percent by weight, based on a total weight of the non-aqueous solvent.

9. The lithium secondary battery of claim 1 ,
wherein the electrolyte further comprises vinylene carbonate, vinyl ethylene carbonate, maleic anhydride, succinic anhydride, or a combination thereof in an amount in a range of about 0.1 percent by weight to about 3 percent by weight, based on the total weight of the electrolyte.

10. The lithium secondary battery of claim 9 , wherein the electrolyte further comprises the maleic anhydride in an amount in a range of about 0.1 percent by weight to about 1.5 percent by weight, based on the total weight of the electrolyte.

11. The lithium secondary battery of claim 1 , wherein the electrolyte further comprises a phosphate compound in an amount in a range of about 0.1 percent by weight to about 3 percent by weight, based on the total weight of the electrolyte.

12. The lithium secondary battery of claim 1 , wherein the electrolyte further comprises a disulfonate compound in an amount in a range of about 0.1 percent by weight to about 3 percent by weight, based on the total weight of the electrolyte.

13. The lithium secondary battery of claim 1 , wherein the cathode active material comprises Li 1.02 Ni 0.86 Co 0.08 Mn 0.04 O 2 , Li 1.02 Ni 0.86 Co 0.08 Al 0.04 O 2 , Li 1.02 Ni 0.88 Co 0.08 Mn 0.04 O 2 , Li 1.02 Ni 0.88 Co 0.08 Al 0.04 O 2 , or Li 1.02 Ni 0.95 Co 0.08 Mn 0.04 O 2 .

14. The lithium secondary battery of claim 1 , wherein the anode further comprises a metal alloyable with lithium.

15. The lithium secondary battery of claim 14 , wherein the metal alloyable with lithium comprises Si particles.

16. The lithium secondary battery of claim 1 , wherein a direct current internal resistance increase after 200 cycles of charging/discharging at a temperature of about 45° C. is less than about 140 percent.

17. The lithium secondary battery of claim 1 , wherein a cell energy density is about 500 watt-hours per liter or greater.

Assignees

• Samsung Electronics Co Ltd
• Samsung Sdi Co Ltd

Inventors

• Roy Basab
• Koh Myongchun
• Kim Dongyoung
• Park Eunha

Classifications

• H01M4/133

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

• H01M2300/0034

  Fluorinated solvents · CPC title

• H01M4/525 Primary

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M10/0568 Primary

  characterised by the solutes · CPC title

• H01M10/052

  Li-accumulators · CPC title