Positive electrode mix for secondary batteries including irreversible additive

Patent metadata

Field	Value
Publication number	US-2016133933-A1
Application number	US-201414891250-A
Country	US
Kind code	A1
Filing date	Jul 28, 2014
Priority date	Jul 30, 2013
Publication date	May 12, 2016
Grant date	—

Abstract

Disclosed is a positive electrode mix for secondary batteries including an irreversible additive. More particularly, provided is a positive electrode mix for secondary batteries including an irreversible additive that decreases irreversible efficiency of a positive electrode active material and a positive electrode.

First claim

1 . A positive electrode mix for secondary batteries comprising an irreversible additive that decreases irreversible efficiency of a positive electrode active material and a positive electrode.

2 . The positive electrode mix according to claim 1 , wherein the irreversible additive has an operation voltage of 1.0 V to 2.5 V with respect to Li.

3 . The positive electrode mix according to claim 1 , wherein the irreversible additive exhibits high conductivity.

4 . The positive electrode mix according to claim 3 , wherein an electric resistance value of the irreversible additive is 5 μΩm to 100 μΩm.

5 . The positive electrode mix according to claim 1 , wherein the irreversible additive is a lithiated lithium titanium oxide (LTO) or a lithium molybdenum compound.

6 . The positive electrode mix according to claim 5 , wherein the irreversible additive is a lithiated lithium titanium oxide represented by Li 7/3 Ti 5/3 O 4 .

7 . The positive electrode mix according to claim 5 , wherein the irreversible additive is lithium molybdenum sulfide represented by Formula 1 below:
Li 2+x Mo 6-y M y S 8-z   (1),
wherein −0.1≦x≦0.5, 0≦y≦0.5, −0.1≦z≦0.5, and M is a metal or transition metal cation having an oxidation number of +2 to +4.

8 . The positive electrode mix according to claim 7 , wherein the lithium molybdenum sulfide is Li 2.3 Mo 6 S 7.7 .

9 . The positive electrode mix according to claim 1 , wherein the irreversible additive is comprised in an amount of 0.1 wt % to 5 wt % with respect to a total weight of the positive electrode mix.

10 . The positive electrode mix according to claim 1 , wherein the positive electrode active material comprises a lithium transition metal oxide represented by Formula 2 or 3 below:
Li x M y Mn 2-y O 4-z A z   (2),
wherein 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; A is at least one monovalent or divalent anion; and 0.9≦x≦1.2, 0<y<2, and 0≦z<0.2,
(1-x)LiM′O 2-y A y -xLi 2 MnO 3-y′ A y′   (3),

wherein M′ is Mn a M b ; M is at least one selected from the group consisting of Ni, Ti, Co, Al, Cu, Fe, Mg, B, Cr, Zr, Zn and Period II transition metals; A is at least one selected from the group consisting of anions such as PO 4 , BO 3 , CO 3 , F and NO 3 ; and 0<x<1, 0<y≦0.02, 0<y′≦0.02, 0.5≦a≦1.0, 0≦b≦0.5, and a+b=1.

11 . The positive electrode mix according to claim 1 , wherein the positive electrode mix further comprises a binder and a conductive material.

12 . The positive electrode mix according to claim 1 , wherein the irreversible additive is uniformly mixed with the positive electrode active material and coated on a positive electrode collector.

13 . The positive electrode mix according to claim 1 , wherein the irreversible additive is coated while forming a layer with the positive electrode active material on a positive electrode collector.

14 . The positive electrode mix according to claim 13 , wherein a thickness of the irreversible additive layer is 0.1% or more and less than 20% with respect to a total thickness of a positive electrode mix layer.

15 . The positive electrode mix according to claim 13 , wherein the irreversible additive layer further comprises a conductive material.

16 . The positive electrode mix according to claim 15 , wherein the conductive material is comprised in an amount of less than 20 wt % with respect to a total weight of the irreversible additive.

17 . A positive electrode manufactured by coating the positive electrode mix according to claim 1 on an electrode collector.

18 . A secondary battery comprising an electrode assembly, which comprises the positive electrode according to claim 17 , a negative electrode, and a separator disposed between the positive electrode and the negative electrode, impregnated with an electrolyte solution.

19 . A secondary battery according to claim 18 , wherein the negative electrode comprises a silicon (Si)-based material as a negative electrode active material.

20 . A secondary battery according to claim 19 , wherein the silicon-based material is a complex of silicon and silicon oxide and/or a silicon alloy.

21 . A secondary battery according to claim 19 , wherein the negative electrode active material further comprises a carbon-based material, and the carbon-based material is comprised in an amount of 70 wt % to 99.9 wt % with respect to the total weight of the negative electrode active material.

22 . A secondary battery according to claim 21 , wherein the carbon-based material is at least one selected from the group consisting of artificial crystalline graphite, natural crystalline graphite, amorphous hard carbon, low-crystalline soft carbon, carbon black, acetylene black, Ketjen black, Super-P, graphene and fibrous carbon.

23 . A secondary battery according to claim 22 , wherein the carbon-based material is artificial crystalline graphite and/or natural crystalline graphite.

24 . A secondary battery according to claim 18 , wherein the secondary battery is a lithium ion battery, a lithium ion polymer battery or a lithium polymer battery.

25 . A battery module comprising secondary battery according to claim 18 as a unit cell.

26 . A battery pack comprising the battery module according to claim 25 .

27 . A device comprising the battery pack according to claim 26 as a power source.

28 . The device according to claim 27 , 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

• Choi Bokkyu
• Kim Seok Koo
• Lee Eun Ju
• Oh Sei Woon
• Kim Je Young

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M2220/20

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

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M10/0525

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

• H01M4/62 Primary

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title