Lithium secondary battery with excellent performance

Patent metadata

Field	Value
Publication number	US-9564635-B2
Application number	US-201414465963-A
Country	US
Kind code	B2
Filing date	Aug 22, 2014
Priority date	Apr 17, 2012
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

Disclosed is a lithium secondary battery including an electrode assembly including a cathode, an anode, and a separator disposed between the cathode and the anode and an electrolyte, wherein the cathode includes a spinel-structure lithium manganese composite oxide represented by Formula 1 below as a cathode active material, and the lithium secondary battery has a charge cut-off voltage of 3.3 to 4 V and, when the charge cut-off voltage is reached, the anode has a potential of 0.75 to 1.545 V within a range within which a potential of the cathode does not exceed 4.95 V:

Li x M y Mn 2−y O 4−z A z   (1)
wherein 0.9≦x≦1.2, 0<y<2, and 0≦z<0.2; M is at least one element selected from the group consisting of Al, Mg, Ni, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, Ti, and Bi; and A is at least one monovalent or divalent anion.

First claim

The invention claimed is:

1. A lithium secondary battery comprising: an electrode assembly comprising a cathode, an anode, and a separator disposed between the cathode and the anode; and an electrolyte, wherein the capacity of the anode is 80 to 100% the capacity of the cathode,
wherein the cathode comprises a spinel-structure lithium manganese composite oxide represented by Formula 1 below as a cathode active material, and
the lithium secondary battery has a charge cut-off voltage of 3.3 to 4 V and, when the charge cut-off voltage is reached, the anode has a potential of 0.75 to 1.545 V within a range within which a potential of the cathode does not exceed 4.95 V:
Li x M y Mn2− y O4− z A z   (1)

wherein 0.9≦x≦1.2, 0<y<2, and 0≦z<0.2;
M is at least one element selected from the group consisting of Al, Mg, Ni, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, Ti, and Bi; and
A is at least one monovalent or divalent anion.

2. The lithium secondary battery according to claim 1 , wherein the charge cut-off voltage of the lithium secondary battery is in a range of 3.3 to 3.5 V and, when the cut-off voltage is reached, the anode has a potential of 1.2 to 1.545 V within a range within which the potential of the cathode does not exceed 4.95 V.

3. The lithium secondary battery according to claim 1 , wherein the lithium manganese composite oxide of Formula 1 is a lithium nickel manganese complex oxide represented by Formula 2 below:
Li x Ni y Mn2− y O4  (2)

wherein 0.9≦x≦1.2 and 0.4≦y≦0.5.

4. The lithium secondary battery according to claim 3 , wherein the lithium nickel manganese complex oxide is LiNi0.5Mn1.5O4 or LiNi0.4Mn1.6O4.

5. The lithium secondary battery according to claim 1 , wherein the anode comprises, as an anode active material, a lithium metal oxide represented by Formula 3 below:
Li a M′ b O4− c A c   (3)

wherein M′ is at least one element selected from the group consisting of Ti, Sn, Cu, Pb, Sb, Zn, Fe, In, Al, and Zr;
0.1≦a≦4 and 0.2≦b≦4 wherein a and b are determined according to oxidation number of M′;
0≦c<0.2 wherein c is determined according to oxidation number of A; and
A is at least one monovalent or divalent anion.

6. The lithium secondary battery according to claim 5 , wherein the lithium metal oxide of Formula 3 is a lithium titanium oxide (LTO) represented by Formula 4 below:
Li a Ti b O4  (4)

wherein 0.5≦a≦3 and 1≦b≦2.5.

7. The lithium secondary battery according to claim 6 , wherein the LTO is Li1.33Ti1.67O4 or LiTi2O4.

8. The lithium secondary battery according to claim 1 , wherein the electrode assembly is a stack-type electrode assembly, a jelly-roll type electrode assembly, or a stack/folding type electrode assembly fabricated by positioning, on a separator film, unit cells comprising cathodes, anodes, and separators and winding the separator film with the unit cells positioned thereon.

9. The lithium secondary battery according to claim 8 , wherein electrodes at outermost sides of the stack-type electrode assembly or stack/folding type electrode assembly are double-sided coated.

10. The lithium secondary battery according to claim 8 , wherein electrodes at outermost sides of the stack-type electrode assembly or stack/folding type electrode assembly are single-sided coated.

11. The lithium secondary battery according to claim 8 , wherein the stack-type electrode assembly or stack/folding type electrode assembly comprises, at outermost sides thereof, A-type bicells, each A-type bicell having a structure of cathode/separator/anode/separator/cathode.

12. The lithium secondary battery according to claim 1 , wherein the potential of the anode is lower than or identical to the capacity of the cathode.

13. The lithium secondary battery according to claim 12 , wherein the capacity of the anode is 80 to 100% the capacity of the cathode.

14. The lithium secondary battery according to claim 13 , wherein a total capacity of anodes constituting the electrode assembly is 90 to 100% a total capacity of cathodes constituting the electrode assembly.

15. A battery module comprising the lithium secondary battery according to claim 1 as a unit battery.

16. A battery pack comprising the battery module according to claim 15 .

17. A device comprising the battery pack according to claim 16 .

18. The device according to claim 17 , wherein the device is an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a system for storing power.

Assignees

• Lg Chemical Ltd

Inventors

• Lim Soo Hyun
• Lee Jae Hyun
• Lee Youn Kyoung

Classifications

• H01M4/485 Primary

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

• Y02E60/122

  Cross-Sectional Technologies · mapped topic

• H01M10/052

  Li-accumulators · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• Y02T10/7011

  Cross-Sectional Technologies · mapped topic