Rechargeable battery including an inorganic anode

Details Rechargeable battery including an inorganic anode Rechargeable battery including an inorganic anode

2000-05-11

2002-08-13

Kalafut, Stephen (Department: 1745)

Chemistry: electrical current producing apparatus, product, and

Current producing cell, elements, subcombinations and...

Electrode

C429S231950, C429S218100, C423S599000

Reexamination Certificate

active

06432581

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to secondary lithium batteries. More particularly, the present invention relates to secondary or rechargeable lithium batteries using a lithium intercalation positive electrode (cathode) and a lithium intercalated negative electrode (anode).
BACKGROUND OF THE INVENTION
Secondary lithium batteries using an intercalation compound as cathode and free lithium metal as anode were studied extensively during the 1980's and 1990's. These studies revealed the inherent dangers of using free lithium and precluded the commercial viability of such batteries. However, substitution of other intercalation compounds for the free lithium metal have proved to be successful.
These successful secondary lithium batteries have focused on the concept of a “rocking chair battery”, which utilize a lithiated intercalation compound as the cathode and a lithium intercalation compound as the anode. Upon charge of such a battery, the lithium deintercalates from the cathode and then intercalates with the anode. During discharge, the lithium flows in the opposite direction from anode to cathode. In other words, the lithium ions are “rocked” back and forth during the charge-discharge cycle.
Because of loss of lithium associated with irreversible secondary reactions in these lithium batteries, an excess of lithium is necessary. This excess lithium may be provided by using an excess of cathode material, however, this results in a significant loss of battery capacity. Alternatively, a stable lithium based cathode containing more than one lithium atom per unit formula may be used.
Prior art cells utilized an LiCoO
2
or an LiNiO
2
cathode material, which have only one lithium ion per unit formula and therefore suffer from the loss of lithium noted above. There is no known Li,CoO
2
phase in which x is greater than one. Further, the instability in air of Li
1+x
NiO
2
prevents the use of this phase as the cathode material.
In light of the above deficiencies with respect to LiCoO
2
and LiNiO
2
cathode materials, U.S. Pat. No. 5,196,279 suggested use of lithium manganese oxide cathode materials and particularly, LiMn
2
O
4
and Li
2
Mn
2
O
4
cathode materials.
The use of Li
2
Mn
2
O
4
as the cathode material is particular advantageous as it provides the excess lithium needed to overcome the loss caused by the irreversible reactions noted above. The '279 patent relates solely to the use of a carbon anode which was the standard at the time and continues to be so. However, it is believed that in the next few years, carbon anodes will be replaced with inorganic electrode materials. These inorganic materials will have a large amount of irreversible lithium loss associated with their use as the anode material. Therefore, there is a need in the art to provide for excess lithium in secondary lithium batteries utilizing inorganic anode compounds.
SUMMARY OF THE INVENTION
In accordance with the present invention, secondary lithium batteries include a lithiated intercalation cathode compound and an inorganic compound for the negative electrode. The cathode compound comprises Li
2
Mn
2−x
Me
x
O
4−z
F
z
wherein 0≦X≦0.5 and can be optimized to match the irreversible capacity loss associated with a chosen inorganic negative electrode and wherein 0≦Z≦0.5 and wherein Me is selected from the group consisting of Al, Cr, Zn, Co, Ni, Li, Mg, Fe, Cu, Ti, Si or combinations thereof. In a preferred embodiment, the cathode compound comprises Li
2
Mn
2
O
4
.
The present invention further provides a rechargeable lithium battery comprising a positive electrode, a negative electrode, an electrically conductive collector associated with at least one electrode, a separator element arranged between the electrodes, wherein the positive electrode includes an intercalation compound of Li
2
Mn
2−x
Me
x
O
4−z
F
z
as set forth above and the negative electrode includes an active inorganic compound.


REFERENCES:
patent: 5196279 (1993-03-01), Tarascon
patent: 5370949 (1994-12-01), Davidson et al.
patent: 5571637 (1996-11-01), Idota
patent: 5639438 (1997-06-01), Ellgen
patent: 5707756 (1998-01-01), Inoue et al.
patent: 5789112 (1998-08-01), Ellgen

Affiliated with

Also associated with

Rating

Rechargeable battery including an inorganic anode does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Rechargeable battery including an inorganic anode, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rechargeable battery including an inorganic anode will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2972722