Manganese oxide composite electrodes for lithium batteries
An activated electrode for a non-aqueous electrochemical cell is disclosed with a precursor thereof a lithium metal oxide with the formula x{zLi 2 MnO 3 •(1-z)LiM′O 2 }.(1-x)LiMn 2−y M y O 4 for 0<x<1; 0≦y≦0.5; and 0<z<1, comprised of layered zLi 2 MnO 3 .(1-z)LiM′O 2 and spinel LiMn 2−y M y O 4 components, physically mixed or blended with one another or separated from one another in a compartmentalized electrode, in which M is one or more metal ions, and in which M′ is selected from one or more first-row transition metal ions, The electrode is activated by removing lithium and lithia, from the precursor. A cell and battery are also disclosed incorporating the disclosed positive electrode.
1. An activated electrode for a non-aqueous electrochemical cell, having as a precursor thereof, a lithium metal oxide with the formula:
x{z Li 2 MnO 3 •(1- z )LiM′O 2 }•(1- x )LiMn 2−y M y O 4
for 0<x<1, 0≦y≦0.5, and 0<z<1, comprising layered zLi 2 MnO 3 .(1-z)LiM′O 2 and spinel LiMn 2−y M y O 4 components, physically mixed with one another or separated from one another in a compartmentalized electrode, in which M is one or more metal ions, and in which M′ is selected from one or more first-row transition metal ions, said activated electrode being activated by removing lithium, lithia, or a combination thereof, from said precursor.
2. The activated electrode of claim 1 , wherein the activated electrode is activated by removing lithium from said precursor.
3. The activated electrode of claim 1 , wherein M comprises one or more monovalent, divalent, trivalent or tetravalent ion.
4. The activated electrode of claim 3 , wherein M is one or more of Li + , Mg 2+ , Ni 2+ , Ni 3+ , Co 2+ , Co 3+ , Al 3+ , Ti 4+ and Zr 4+ ions.
5. The activated electrode of claim 4 , wherein M is one or more of Li + , Ni 2+ and Ni 3+ ions.
6. The activated electrode of claim 5 , wherein M is Li + .
7. The activated electrode of claim 1 , wherein M′ is one or more of Mn, Co, and Ni ions.
8. The activated electrode of claim 1 , wherein M′ is replaced by 10% or less of Li, Mg and/or Al ions on a molar basis.
9. The activated electrode of claim 1 , wherein the Li 2 MnO 3 and LiM′O 2 subcomponents of the {zLi 2 MnO 3 •(1-z)LiM′O 2 }•(1-x)LiMn 2−y M y O 4 component are integrated at the atomic level in a complex structural arrangement.
10. The activated electrode of claim 1 , wherein the M cations of the spinel component partially substitute for the manganese ions, or lithium and manganese ions of the layered Li 2 MnO 3 subcomponent of the {zLi 2 MnO 3 •(1-z)LiM′O 2 }•(1-x)LiMn 2−y M y O 4 component.
11. The activated electrode of claim 1 , wherein the components thereof are partially reduced to provide mixed Mn 4+/3+ valence in the precursor.
12. The activated electrode of claim 1 , wherein the electrode precursor is activated electrochemically.
13. The activated electrode of claim 1 , wherein the electrode precursor is activated chemically with an acid.
14. An electrochemical cell comprising the activated electrode of claim 1 , a negative electrode, and an electrolyte therebetween, said activated electrode being activated by removing lithium and lithia, from said precursor.
15. An electrochemical cell comprising the activated electrode of claim 2 , a negative electrode, and an electrolyte therebetween, said activated electrode being activated by removing lithium from said precursor.
16. A battery comprising a plurality of electrochemical cells of claim 14 arranged in parallel, in series, or both.
17. A battery comprising a plurality of electrochemical cells of claim 15 arranged in parallel, in series, or both.