Lithium metal oxide electrodes for lithium cells and batteries

Details Lithium metal oxide electrodes for lithium cells and batteries Lithium metal oxide electrodes for lithium cells and batteries

2001-06-21

2004-01-13

Weiner, Laura (Department: 1745)

Chemistry: electrical current producing apparatus, product, and

Current producing cell, elements, subcombinations and...

Electrode

C429S223000, C429S231100, C429S231600, C429S231300, C423S599000

Reexamination Certificate

active

06677082

ABSTRACT:

BACKGROUND OF THE INVENTION
This invention relates to lithium metal oxide positive electrodes for non-aqueous lithium cells and batteries. More specifically, it relates to lithium-metal-oxide electrode compositions and structures, having in their initial state in an electrochemical cell, a general formula xLiMO
2
.(1-x)Li
2
M′O
3
alternatively Li
2-x
M
x
M′
1-x
O
3-x
in which 0<x<1 and where M is one or more trivalent ion with at least one ion being Mn, and where M is one or more tetravalent ions selected preferably from Mn, Ti and Zr; or, where M is one or more trivalent ion with at least one ion being Ni, and where M′ is one or more tetravalent ion with at least one ion being Mn. In one embodiment of the invention, the Mn content should be as high as possible, such that the LiMO
2
component is essentially LiMnO
2
modified in accordance with this invention. In a further embodiment of the invention, the transition metal ions and lithium ions may be partially replaced by minor concentrations of one or more mono- or multivalent cations such as H
+
derived from the electrolyte by ion-exchange with Li
+
ions, and/or Mg
2+
and Al
3+
to impart improved structural stability or electronic conductivity to the electrode during electrochemical cycling.
SUMMARY OF THE INVENTION
Lithium-metal oxide compounds of general formula LiMO
2
, where M is a trivalent transition metal cation Co, Ni, Mn, Ti, V, Fe, and with electrochemically inactive substituents such as Al are very well known and are of interest as positive electrodes for rechargeable lithium batteries. The best-known electrode material is LiCoO
2
, which has a layered-type structure and is relatively expensive compared to the isostructural nickel and manganese-based compounds. Efforts are therefore being made to develop less costly electrodes, for example, by partially substituting the cobalt ions within LiCoO
2
by nickel, such as in LiNi
0.8
Co
0.2
O
2
or by exploiting the manganese-based system LiMnO
2
. Such layered compounds are sometimes stabilized by partially replacing the transition metal cations within the layers by other metal cations, either alone or in combination. For example, Mg
2+
ions may be introduced into the structure to improve the electronic conductivity of the electrode, or Al
3+
or Ti
4+
ions to improve the structural stability of the electrode at high levels of delithiation. Examples of such compounds are LiNi
0.8
Co
0.15
Al
0.05
O
2
and LiNi
0.75
Co
0.15
Ti
0.05
Mg
0.05
O
2
.
A major problem of layered LiMO
2
compounds containing either Co or Ni (or both) is that the trivalent transition metal cations, M, are oxidized during charge of the cells to a metastable tetravalent oxidation state. Such compounds are highly oxidizing materials and can react with the electrolyte or release oxygen. These electrode materials can, therefore, suffer from structural instability in charged cells when, for example, more than 50% of the lithium is extracted from their structures; they require stabilization to combat such chemical degradation.
Although the layered manganese compound LiMnO
2
has been successfully synthesized in the laboratory, it has been found that delithiation of the structure and subsequent cycling of the Li
x
MnO
2
electrode in electrochemical cells causes a transition from the layered MnO
2
configuration to the configuration of a spinel-type [Mn
2
]O
4
structure. This transformation changes the voltage profile of the Li/Li
x
MnO
2
cell such that it delivers capacity over both a 4V and a 3V plateau; cycling over the 3V plateau is not fully reversible which leads to capacity fade of the cell over long-term cycling. Other types of LiMnO
2
structures exist, such as the orthorhombic-form, designated O-LiMnO
2
in which sheets of MnO
6
octahedra are staggered in zig—zig fashion unlike their arrangement in layered LiMnO
2
. However, O-LiMnO
2
behaves in a similar way to layered LiMnO
2
in lithium cells; it also converts to a spinel-like structure on electrochemical cycling.
Therefore, further improvements must be made to LiMO
2
electrodes, particularly LiMnO
2
, to impart greater structural stability to these electrode materials during electrochemical cycling in lithium cells and batteries. This invention addresses the stability of LiMO
2
electrode structures, particularly LiMnO
2
, and makes use of a Li
2
M′O
3
component to improve their stability.


REFERENCES:
patent: 5153081 (1992-10-01), Thackeray et al.
patent: 5393622 (1995-02-01), Nitta et al.
patent: 6017654 (2000-01-01), Kumta et al.
patent: 6221531 (2001-04-01), Vaughey et al.
patent: 6551743 (2003-04-01), Nakanishi et al.
patent: 2002/0136954 (2002-09-01), Thackeray et al.
patent: 2003/0022063 (2003-01-01), Paulsen et al.
patent: 2003/0027048 (2003-02-01), Lu et al.
patent: WO 00/23380 (2000-04-01), None
Material Res. Bulletin vol. 15, pp. 783-789, 1980, “A New Cathode Material for Batteries of High Energy Density”, K. Mizushima et al.
Electrochemical Society vol. 144, No. 8, Aug. 1997, Morphology Effects on The Electrochemical Performance of . . . , W. Li et al., pp. 2773-2779.
Electrochemical and Solid State . . . 117-119 (1998) Novel . . . Compounds as Cathode Material for Safer Lithium-Ion Batteries, Yuan Gao et al.
Journal of Power Sources 90 (2000) 76-81, “Lithium Nickelate Electrodes With Enhanced . . . Thermal Stability,” Hajime Arai et al.
Electrochemical Society vol. 144, Sep., 9, 1997, Electrochemical and Thermal Behavior of . . . , Hajime Arai et al., pp. 3117-3125.
Nature, vol. 381, Jun. 6, 1996, Synthesis of Layered . . . Lithium Batteries, A. Robert Armstrong et al. pp. 499-500.
Mat. Res. Bull. vol. 26, pp. 463-473, 1991, Lithium Manganese Oxides From . . . Battery Applications, M.H. Rossouw et al.
Journal of Solid State Chemistry, 104, 464-466 (1993), Synthesis and Structural Characterization . . . Lithiated Derivative . . . , M.H. Rossouw et al.
The Electrochemical Society, Inc. Meeting Abstract No. 16, Boston, Nov. 1-6, 1998, Layered Lithium-Manganese Oxide . . . Precursors, Christopher S. Johnson et al.
Journal of Power Sources 81-82 (1999) 491-495, “Structural and Electrochemical Analysis . . . ”, C. S. Johnson et al.
10th International Meeting on Lithium Batteries, “Lithium 2000”, Como, Italy, May 28-Jun. 2, 2000, Abstract No. 17, B. Amundsen et al.
Solid State Ionics 118 (1999) 117-120, Preparation and Electrochemical Properties . . . , K. Numata et al.
Solid State Ionics, vol. 57m, p. 311 (1992), R. Rossen et al.
Power Sources, vol. 74, p. 46 (1998), M. Yoshio et al.
J. Electrochem. Soc., vol. 145, p. 1113 (1998) Yuoshio M. et al.
Chem. Commun. vol. 17, p. 1833 (1998); Armstrong A. R. et al.
J. Mat. Chem., vol. 9, p. 193 1999); P. G. Bruce et al.
J. Solid State Chem., vol. 145, p. 549 (1999). Armstrong, A. R.
J. Power Source, vol. 54, p. 205 (1995); Davidson, I. J. et al.
K. Mizushima, P.J. Wiseman and J.B. Goodenough, Mat. Res. Bull, 15 783-789 (1980).
W. Li and J.C. Currie, J. Electrochem. Soc., 144, 2773-2779 (1997.
Y. Gao, M.V. Yakovleva and W.B. Ebner, Electrochem. and Solid-State Lett., 1, 117-119 (1998).
H. Arai, M. Tsuda and Y. Sakurai, J. Power Sources, 90, 76-81 (2000).
H. Arai, S. Okada, Y. Sakurai and J. Yamaki, . Electrochem. soc., 144, 3117-3125 (1997).
Armstrong and P.G. Bruce, Nature, 381, 499-500 (1996).
M.H. Rossouw and M. M. Thackeray, J.Solid State Chem. 104, 464-473 1993).
M.H. Rossouw, D.C. Liles and M.M. Thakeray, J. Solid State Chem. 104, 464-466 (1993).
C.S. Johnson, J.T. Vaughey, M.M. Thackeray, T.E. Bofinger and S.A. Hackney, Ext. Abstract No. 136, 194thMeeting of the Electrochemical Society Boston, USA, Nov. 1-6, 1998.
S. Johnson, S.D. Korte, J.T. Vaughey, M.M.Thackeray, T.E. Bofinger, Y. Shao-Horn and S.A. Hackney, J. PowerSources 81-82, 491-495 (1999).
B. Amundsen, 10thInternational Meeting on Lithium Batteries, Como, Italy, May 28-Jun. 2, 2000.
K. Numata and S. Yamanaka, Solid State ionics, 118, 117 (1999).

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