Lithium-ion batteries with intrinsic pulse overcharge protection

• US 20070178370A1
• Filed: 02/02/2006
• Published: 08/02/2007
• Est. Priority Date: 02/02/2006
• Status: Active Grant

• Current Assignee: U Chicago Argonne, LLC
• Original Assignee: University of Chicago
• Inventors: Amine, Khalil, Chen, Zonghai
• Granted Patent: US 8,367,253 B2
• Time in Patent Office: Days
• US Class Current: 429/105
• CPC Class Codes: H01M 10/0567 characterised by the additives
• CPC Class Codes: H01M 2004/028 Positive electrodes
• 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 4/136 Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/1391 of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/5825 Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The present invention relates in general to the field of lithium rechargeable batteries, and more particularly relates to the positive electrode design of lithium-ion batteries with improved high-rate pulse overcharge protection. Thus the present invention provides electrochemical devices containing a cathode comprising at least one primary positive material and at least one secondary positive material; an anode; and a non-aqueous electrolyte comprising a redox shuttle additive; wherein the redox potential of the redox shuttle additive is greater than the redox potential of the primary positive material; the redox potential of the redox shuttle additive is lower than the redox potential of the secondary positive material; and the redox shuttle additive is stable at least up to the redox potential of the secondary positive material.

Claims

1. An electrochemical device comprising:

a cathode comprising at least one primary positive material and at least one secondary positive material;

an anode; and

a non-aqueous electrolyte comprising a redox shuttle additive;

wherein

the redox potential of the redox shuttle additive is greater than the redox potential of the primary positive material;

the redox potential of the redox shuttle additive is lower than the redox potential of the secondary positive material; and

the redox shuttle additive is stable at least up to the redox potential of the secondary positive material.

2. The electrochemical device of claim 1, wherein the primary positive material is a lithium metal oxide or a mixture of two or more lithium metal oxides, and the secondary positive material is a lithium metal oxide or a mixture of two or more lithium metal oxides.

3. The electrochemical device of claim 1, wherein the primary positive material is selected from the group consisting of:

Li₂S, spinel, olivine, carbon-coated olivine, LiFePO₄, LiCoO₂, LiNiO₂, LiNi<sub>1−

x</sub>Co_yMet_zO₂, LiMn_0.5Ni_0.5O₂, LiMn_0.3Co_0.3Ni_0.3O₂, LiMn₂O₄, LiFeO₂, LiMet_0.5Mn_1.5O₄, Li_1+xMn<sub>2−

x</sub>O₄, Li_1+x′

Ni_α

Mn_β

Co_γ

Met′

_δ

O<sub>2−

z′</sub>

Y_z′

, A_n′

B₂(XO₄)₃, Li_1+xMn<sub>2−

x</sub>O₄, and mixtures of any two or more thereof, wherein Met is Al, Mg, Ti, B, Ga, Si, Mn, or Co;

Met′

is Mg, Zn, Al, Ga, B, Zr, or Ti;

A is Li, Ag, Cu, Na, Mn, Fe, Co, Ni, Cu, or Zn;

B is Ti, V, Cr, Fe, or Zr;

X is P, S, Si, W, or Mo;

Y is F or S; and

further wherein 0≦

x≦

0.3, 0y≦

0.5, 0≦

z≦

0.5;

0≦

x′

≦

0.4, 0≦

α

≦

1, 0≦

β

≦

1, 0≦

γ

≦

1, 0≦

δ

≦

0.4, and 0z′

≦

0.4; and

0≦

n′

≦

3.

4. The electrochemical device of claim 1, wherein the primary positive is selected from the group consisting of:

spinel, olivine, carbon-coated olivine, Li_1+xMn<sub>2−

z</sub>Met_yO<sub>4−

m</sub>X_n, LiFe<sub>1−

z</sub>Met″

_yPO<sub>4−

m</sub>X_n, and mixtures of any two or more thereof, wherein Met is Al, Mg, Ti, B, Ga, Si, Ni, or Co;

Met″

is Al, Mg, Ti, B, Ga, Si, Ni, Mn or Co;

X is S or F;

0≦

x≦

0.3, 0≦

y≦

0.5, 0≦

z≦

0.5, 0≦

m≦

0.5, and 0≦

n≦

0.5.

5. The electrochemical device of claim 1, wherein the primary positive electrode material may be further stabilized by surface coating the particles of the spinel or olivine with a metal oxide selected from the group consisting of:

ZrO₂, TiO₂, ZnO₂, WO₃, Al₂O₃, MgO, SiO₂, SnO₂ AlPO₄, Al(OH)₃, and mixtures of any two or more thereof.

6. The electrochemical device of claim 1, wherein the secondary positive material is selected from the group consisting of:

spinel, olivine, carbon-coated olivine, LiFePO₄, LiCoO₂, LiNiO₂, LiNi<sub>1−

x</sub>Co_yMet_zO₂, LiMn_0.5Ni_0.5O₂, LiMn_0.3Co_0.3Ni_0.3O₂, LiMn₂O₄, LiFeO₂, LiMet_0.5Mn_1.5O₄, Li_1+x′

Ni_α

Mn_β

Co_γ

Met′

_γ

O<sub>2−

z′</sub>

Y_z′

, A_n′

B₂(XO₄)₃, Li_1+xMn<sub>2−

x</sub>O₄, LiMn<sub>1−

x″

−

y″</sub>

Ni_x″

Co_y″

O₂ and mixtures of any two or more thereof, wherein Met is Al, Mg, Ti, B, Ga, Si, Mn, or Co;

Met′

is Mg, Zn, Al, Ga, B, Zr, or Ti;

A is Li, Ag, Cu, Na, Mn, Fe, Co, Ni, Cu, are Zn;

B is Ti, V, Cr, Fe, or Zr;

X is P, S, Si, W, or Mo;

Y is F or S; and

further wherein 0≦

x≦

0.3, 0≦

y≦

0.5, 0≦

z≦

0.5;

0≦

x′

≦

0.4, 0≦

α

≦

1, 0≦

β

≦

1, 0≦

γ

≦

1, 0≦

δ

≦

0.4, and 0≦

z′

≦

0.4;

0≦

n′

≦

3; and

0≦

x″

≦

1, 0≦

y″

≦

1, and 0≦

x″

+y″

≦

1.

7. The electrochemical device of claim 1, wherein the secondary positive material is selected from the group consisting of:

spinel, olivine, carbon-coated olivine, Li_1+xMn<sub>2−

z</sub>Met_yO<sub>4−

m</sub>X_n, LiFe<sub>1−

z</sub>Met″

_yPO<sub>4−

m</sub>X_n, and mixtures of any two or more thereof, wherein Met is Al, Mg, Ti, B, Ga, Si, Ni, or Co;

Met″

is Al, Mg, Ti, B, Ga, Si, Ni, Mn or Co;

X is S or F;

0≦

x≦

0.3, 0≦

y≦

0.5, 0≦

z≦

0.5, 0≦

m≦

0.5, and 0≦

n≦

0.5.

8. The electrochemical device of claim 1, wherein the secondary positive electrode material may be further stabilized by surface coating the particles of the spinel or olivine with a metal oxide selected from the group consisting of:

ZrO₂, TiO₂, ZnO₂, WO₃, Al₂O₃, MgO, SiO₂, SnO₂ AlPO₄, Al(OH)₃, and mixtures of any two or more thereof.

9. The electrochemical device of claim 1, wherein the redox shuttle additive is substituted or unsubstituted ferrocene, or a mixture of two or more thereof.

10. The electrochemical device of claim 1, wherein the redox shuttle additive is a substituted or unsubstituted aromatic compound.

11. The electrochemical device of claim 10, wherein the substituted aromatic compound is a compound of formula I:

12. The electrochemical device of claim 11, wherein two or more of R₁, R₂, R₃, R₄, R₅ and R₆ are each independently an —

O-alkyl, —

O-aryl, or —

O-heteroaryl group.

13. The electrochemical device of claim 1, wherein the redox shuttle additive is 2,5-di-(tert-butyl)-1,4-dimethoxybenzene, or a mixture of 2,5-di-(tert-butyl)-1,4-dimethoxybenzene and (tetrafluorobenzo-1,2-dioxyl)-pentafluorophenyl-borane.

14. The electrochemical device of claim 1, wherein the redox shuttle additive is Li₂B₁₀X₁₀ or Li₂B₁₂X₁₂;

wherein each X is independently selected from the group consisting of H, F, Cl, Br, I, OCH₃, and OH.

15. The electrochemical device of claim 1, wherein the redox shuttle additive has a redox potential vs. Li⁰ from about 3.0 V to about 5.0 V.

16. The electrochemical device of claim 15, wherein the redox shuttle additive is Li₂B₁₀X₁₀ or Li₂B₁₂X₁₂;

wherein each X is independently selected from the group consisting of H, F, Cl, Br, I, OCH₃, and OH.

17. The electrochemical device of claim 1, wherein the redox shuttle additive is a mixture of two or more compounds selected from the group consisting of

substituted or unsubstituted ferrocene;

2,5-di-(tert-butyl)-1,4-dimethoxybenzene;

(tetrafluorobenzo-1,2-dioxyl)-pentafluorophenyl-borane;

Li₂B₁₀X₁₀ or Li₂B₁₂X₁₂, wherein each X is independently selected from the group consisting of H, F, Cl, Br, I, OCH₃, and OH; and

a compound of formula I;

wherein;

R₁, R₂, R₃, R₄, R₅ and R₆ are each independently selected from the group consisting of H, —

F, —

Cl, —

Br, —

I, haloalkyl, cycloalkyl, alkyl, aryl, heteroaryl, —

CN, —

NO₂, —

O-alkyl, —

O-aryl, —

O-heteroaryl, —

S-alkyl, —

S-aryl, —

S-heteroaryl, and a moiety selected from the group consisting of;

provided that at least one of R₁, R₂, R₃, R₄, R₅ and R₆ is not H;

or any two adjacent groups of R₁, R₂, R₃, R₄, R₅ and R₆ together form a fused aryl or heteroaryl ring;

each R₇, R₈ and R₉ is independently a hydrogen, halogen, an alkyl group, an aryl group, a haloalkyl group, or a haloaryl group;

each R₁₀, R₁₁ and R₁₂ is independently a halogen atom, an alkyl group, an aryl group, a haloalkyl group, or a haloaryl group;

M⁺ is a cation; and

A⁻

is an anion.

18. The electrochemical device of claim 1, wherein the electrolyte further comprises a lithium salt.

19. The electrochemical device of claim 18, wherein the lithium salt is Li[B(C₂O₄)₂], Li[BF₂(C₂O₄)], Li[PF₂(C₂O₄)₂], LiClO₄, LiBF₄, LiAsF₆, LiPF₆LiCF₃SO₃, Li[N(CF₃SO₂)₂], Li[C(CF₃SO₂)₃], Li[N(SO₂C₂F₅)₂], lithium alkyl fluorophosphates, or a mixture of any two or more thereof.

20. The electrochemical device of claim 18, wherein the lithium salt is Li₂B₁₀X₁₀ or Li₂B₁₂X₁₂;

wherein each X is independently selected from the group consisting of H, F, Cl, Br, I, OCH₃, and OH.

21. The electrochemical device of claim 18, wherein the lithium salt is a mixture of two or more of:

Li[B(C₂O₄)₂], Li[BF₂(C₂O₄)], Li[PF₂(C₂O₄)₂], LiClO₄, LiBF₄, LiAsF₆, LiPF₆, LiCF₃SO₃, Li[N(CF₃SO₂)₂], Li[C(CF₃SO₂)₃], Li[N(SO₂C₂F₅)₂], Li₂B₁₀X₁₀, and Li₂B₁₂X₁₂;

wherein each X is independently selected from the group consisting of H, F, Cl, Br, I, OCH₃, and OH.

22. The electrochemical device of claim 1, wherein

the electrochemical device is a lithium secondary battery;

the primary positive material is a lithium metal oxide or a mixture of two or more lithium metal oxides;

the secondary positive material is a lithium metal oxide or a mixture of two or more lithium metal oxides different from the primary positive material;

the anode is graphite, amorphous carbon, Li₄Ti₅O₁₂, tin alloys, silicon alloys, intermetallic compounds, lithium metal, or mixtures of any two or more thereof; and

the anode and cathode are separated from each other by a porous separator.

23. The electrochemical device of claim 22, wherein the redox shuttle additive is a mixture of two or more compounds selected from the group consisting of:

substituted or unsubstituted ferrocene;

2,5-di-(tert-butyl)-1,4-dimethoxybenzene;

(tetrafluorobenzo-1,2-dioxyl)-pentafluorophenyl-borane;

Li₂B₁₀X₁₀ or Li₂B₁₂X₁₂, wherein each X is independently selected from the group consisting of H, F, Cl, Br, I, OCH₃, and OH; and

a compound of formula I;

wherein;

R₁, R₂, R₃, R₄, R₅ and R₆ are each independently selected from the group consisting of H, —

F, —

Cl, —

Br, —

I, haloalkyl, cycloalkyl, alkyl, aryl, heteroaryl, —

CN, —

NO₂, —

O-alkyl, —

O-aryl, —

O-heteroaryl, —

S-alkyl, —

S-aryl, —

S-heteroaryl, and a moiety selected from the group consisting of;

provided that at least one of R₁, R₂, R₃, R₄, R₅ and R₆ is not H;

or any two adjacent groups of R₁, R₂, R₃, R₄, R₅ and R₆ together form a fused aryl or heteroaryl ring;

each R₇, R₈ and R₉ is independently a hydrogen, halogen, an alkyl group, an aryl group, a haloalkyl group, or a haloaryl group;

each R₁₀, R₁₁ and R₁₂ is independently a halogen atom, an alkyl group, an aryl group, a haloalkyl group, or a haloaryl group;

M⁺ is a cation; and

A⁻

is an anion.

24. The electrochemical device of claim 1, wherein

the electrochemical device is a lithium secondary battery;

the primary positive material and the second positive material are the same material and further wherein the material exhibits different voltage potentials at zero charge and full charge;

the anode is graphite, amorphous carbon, Li₄Ti₅O₁₂, tin alloys, silicon alloys, intermetallic compounds, lithium metal, or mixtures of any two or more thereof; and

the anode and cathode are separated from each other by a porous separator.

25. A electrochemical device comprising:

a cathode comprising at least one primary positive material and at least one secondary positive material;

an anode; and

a non-aqueous electrolyte comprising;

Li₂B₁₀X₁₀, Li₂B₁₂X₁₂, or a mixture thereof;

wherein each X is independently selected from the group consisting of H, F, Cl, Br, I, OCH₃, and OH;

a polar aprotic solvent; and

a redox shuttle additive;

wherein,

the primary positive material is LiFePO₄;

the secondary positive material is spinel, LiMn₂O₄, LiCoO₂, LiCo<sub>1−

α

′</sub>

Al<sub>α

′</sub>

O₂, or Li_1+x′

Ni_α

Mn_β

Co_yMet′

_δ

O<sub>2−

z′</sub>

Y_z′

, wherein Met′

is Mg, Zn, Al, Ga, B, Zr, or Ti;

A is Li, Ag, Cu, Na, Mn, Fe, Co, Ni, Cu, and Zn;

Y is F or S;

0≦

α

≦

0.2, 0≦

x′

≦

0.4, 0≦

α

1, 0≦

β

≦

1, 0≦

γ

≦

1, 0≦

δ

≦

0.4, and 0≦

z′

≦

0.4; and

the redox shuttle is 2,5-di-(tert-butyl)-1,4-dimethoxybenzene.