Lithium secondary battery

Patent metadata

Field	Value
Publication number	US-2017237123-A1
Application number	US-201715581925-A
Country	US
Kind code	A1
Filing date	Apr 28, 2017
Priority date	Nov 22, 2012
Publication date	Aug 17, 2017
Grant date	—

Abstract

Disclosed is a lithium secondary battery including: (i) a cathode active material including a lithium metal phosphate according to Formula 1 below; (ii) an anode active material including amorphous carbon; and (iii) an electrolyte for lithium secondary batteries including a lithium salt and an ether based solvent, wherein propylene carbonate (PC) is included in an amount of 1 wt % to 60 wt % in the electrolyte for lithium secondary batteries, based on the total weight of the electrolyte,
Li 1+a M(PO 4−b )X b   (1)
wherein M is at least one selected from metals of Groups II to XII; X is at least one selected from F, S and N, −0.5≦a≦+0.5, and 0≦b≦0.1.

First claim

1 . A lithium secondary battery comprising:
a cathode active material comprising a lithium metal phosphate according to Formula 1 below; an anode active material comprising amorphous carbon; and an electrolyte for lithium secondary batteries comprising a lithium salt, propylene carbonate (PC) and ethylene glycol dimethyl ether, wherein propylene carbonate (PC) is comprised in an amount of 1 wt % to 60 wt % in the electrolyte for lithium secondary batteries, based on a total weight of the electrolyte,
Li 1+a M(PO 4−b )X b   (1)

wherein M is at least one selected from metals of Groups II to XII; X is at least one selected from F, S and N, −0.5≦a≦+0.5, and 0≦b≦0.1.

2 . The lithium secondary battery according to claim 1 , wherein the propylene carbonate (PC) is comprised in an amount of 1 to 40 wt % based on a total weight of the electrolyte.

3 . The lithium secondary battery according to claim 1 , wherein the lithium salt is at least one selected from the group consisting of LiCl, LiBr, LiI, LiClO 4 , LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiAsF 6 , LiSbF 6 , LiPF 6 , LiAlCl 4 , CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2 ) 2 NLi, chloroborane lithium, lithium tetraphenyl borate, and imides, and has a concentration of 0.5 to 3 M in the electrolyte.

4 . The lithium secondary battery according to claim 1 , wherein the lithium metal phosphate is a lithium iron phosphate having an olivine crystal structure according to Formula 2 below:
Li 1+a Fe 1−x M′ x (PO 4−b )X b   (2)
wherein M′ is at least one selected from Al, Mg, Ni, Co, Mn, Ti, Ga, Cu, V, Nb, Zr, Ce, In, Zn, and Y, X is at least one selected from F, S, and N, and −0.5≦a≦+0.5, 0≦x≦0.5, and 0≦b≦0.1.

5 . The lithium secondary battery according to claim 4 , wherein the lithium iron phosphate having the olivine crystal structure is LiFePO 4 .

6 . The lithium secondary battery according to claim 5 , wherein the lithium iron phosphate having the olivine crystal structure is coated with conductive carbon.

7 . The lithium secondary battery according to claim 1 , wherein the amorphous carbon is hard carbon and/or soft carbon.

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

9 . A battery pack comprising the battery module according to claim 8 .

10 . A device comprising the battery pack according to claim 9 .

11 . The device according to claim 10 , wherein the device is a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a system for storing power.

Assignees

• Lg Chemical Ltd

Inventors

• Yoon Yourim
• Jung Jong Mo
• Chae Jonghyun
• Lee Chul Haeng
• Chung Geun Chang
• Choi Young Cheol
• Choi Young Geun
• Yoon Seung Jae

Classifications

• H01M2300/0037

  Mixture of solvents · CPC title

• H01M10/0525

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

• H01M4/625

  Carbon or graphite · CPC title

• H01M10/0569 Primary

  characterised by the solvents · CPC title

• H01M4/366

  as layered products · CPC title