ELECTROLYTE FOR LITHIUM SECONDARY BATTERY AND LITHIUM SECONDARY BATTERY INCLUDING THE SAME

• US 20150017515A1
• Filed: 09/30/2014
• Published: 01/15/2015
• Est. Priority Date: 04/20/2012
• Status: Active Grant

• Current Assignee: LG Energy Solution Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Jeon, Jong Ho, Kim, Yoo Seok, Yang, Doo Kyung, Kim, Shulkee
• Granted Patent: US 9,954,254 B2
• Time in Patent Office: Days
• US Class Current: 429/156
• CPC Class Codes: H01M 10/052 Li-accumulators
• 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 10/0569 characterised by the solvents
• CPC Class Codes: H01M 2220/10 Batteries in stationary systems, e.g. emergency power source in plant
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 2300/0037 Mixture of 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 4/485 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 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Disclosed are an electrolyte for a lithium secondary battery which includes a non-aqueous solvent and a lithium salt and a lithium secondary battery including the same. The electrolyte includes 1 to 60 wt % of a cyclic carbonate and 40 to 99 wt % of a linear solvent based on a total weight of the non-aqueous solvent.

Claims

1. An electrolyte for a lithium secondary battery, comprising a non-aqueous solvent and a lithium salt, the electrolyte comprising 1 to 60 wt % of a cyclic carbonate and 40 to 99 wt % of a linear solvent based on a total weight of the non-aqueous solvent.

2. The electrolyte according to claim 1, wherein the cyclic carbonate is at least one selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), and fluoroethylene carbonate (FEC).

3. The electrolyte according to claim 1, wherein the linear solvent is at least one linear carbonate or ester selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), ethylmethyl carbonate (EMC), and methyl propionate (MP).

4. The electrolyte according to claim 1, wherein the cyclic carbonate is FEC, and the linear solvent is DMC or MP.

5. The electrolyte according to claim 1, wherein the electrolyte comprises 5 to 50 wt % of the cyclic carbonate and 50 to 95 wt % of the linear solvent.

6. A lithium secondary battery comprising the electrolyte according to claim 1.

7. The lithium secondary battery according to claim 6, wherein the lithium secondary battery comprises:

a cathode comprising a spinel-structure lithium nickel manganese composite oxide represented by Formula 1 below as a cathode active material; and

an anode comprising a lithium metal oxide represented by Formula 2 below as an anode active material;

Li_xM_yMn_2-yO_4-zA_z  

 

(1)

Li_aM′

_bO_4-cA′

_c  

 

(2)

wherein, in Formula 1, 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,

wherein, in Formula 2, 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.

8. The lithium secondary battery according to claim 7, wherein the spinel-structure lithium nickel manganese composite oxide of Formula 1 is represented by Formula 3 below:

Li_xNi_yMn_2-yO₄  

 

(3)

wherein 0.9≦

x≦

1.2 and 0.4≦

y≦

0.5.

9. The lithium secondary battery according to claim 8, wherein the spinel-structure lithium nickel manganese composite oxide of Formula 3 is LiNi_0.5Mn_1.5O₄ or LiNi_0.4Mn_1.6O₄.

10. The lithium secondary battery according to claim 7, wherein the lithium metal oxide of Formula 2 is a lithium metal oxide represented by Formula 4 below:

Li_aTi_bO₄  

 

(4)

wherein 0.5≦

a≦

3 and 1≦

b≦

2.5.

11. The lithium secondary battery according to claim 10, wherein the lithium metal oxide of Formula 4 is Li_1.33Ti_1.67O₄ or LiTi₂O₄.

12. A battery module comprising the lithium secondary battery according to claim 7 as a unit cell.

13. A battery pack comprising the battery module according to claim 12.

14. A device comprising the battery pack according to claim 13.

15. The device according to claim 14, wherein the device is an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a system for storing power.