Lithium battery electrodes
Electrode materials for electrochemical cells and batteries and methods of producing such materials are disclosed herein. The electrode materials comprise an active lithium metal oxide material prepared by: (a) contacting the lithium metal oxide material with an aqueous acidic solution containing one or more metal cations; and (b) heating the so-contacted lithium metal oxide from step (a) to dryness at a temperature below 200° C. The metal cations in the aqueous acidic solution comprise one or more metal cations selected from the group consisting of an alkaline earth metal ion, a transition metal ion, and a main group metal ion.
1. An electrode for a non-aqueous electrochemical cell comprising an active lithium metal oxide material coated on a current collector; wherein the active lithium metal oxide material is prepared by a method comprising the sequential steps of:
(a) contacting a first lithium metal oxide material with an aqueous acidic solution containing one or more metal cations; and
(b) heating the so-contacted first lithium metal oxide material from step (a) to dryness at a temperature below 200° C. to form the active lithium metal oxide material;
wherein the metal cations in the aqueous acidic solution comprise one or more metal cations selected from the group consisting of an alkaline earth metal ion, a transition metal ion, and aluminum ion; and wherein the first lithium metal oxide material in step (a) comprises a compound with a structurally-integrated layered-layered structure comprising xLi 2 MnO 3 .(1−x) LiMO 2 or a layered-layered-spinel structure comprising y[xLi 2 MnO 3 .(1−x)LiMO 2 ].(1−y)LiM″ 2 O 4 , in which M and M″ comprise one or more metal ions for 0<x<1 and 0<y<1.
2. The electrode of claim 1 , wherein M and M″ comprise one or more metal ions selected from the group consisting of Mn, Ni, and Co cations, and optionally, one or more other metal ions selected from the group consisting of Al, Mg and Li cations.
3. The electrode of claim 1 , wherein the active lithium metal oxide material comprises Mn and Ni in an atomic ratio of Mn:Ni greater than or equal to 1.
4. The electrode of claim 1 , wherein the active lithium metal oxide material comprises Mn, Ni and Co in an atomic ratio of Mn:(Ni+Co) greater than or equal to 1.
5. The electrode of claim 1 , wherein the aqueous acidic solution comprises aluminum ion and the active lithium metal oxide material exhibits a peak of about 531.5 eV adjacent to a peak at about 529.5 eV in an XPS spectrum of the material.
6. An electrochemical cell comprising a cathode, an anode, a separator membrane between the cathode and the anode, and a lithium-containing electrolyte contacting the anode, the cathode, and the membrane, wherein either the cathode or the anode is the electrode of claim 1 .
7. The electrochemical cell of claim 6 , wherein the electrolyte comprises up to about 1 percent by weight of lithium difluoro(oxalate)borate (LiDFOB).
8. A battery containing more than one electrochemical cell of claim 7 , connected in series, in parallel, or in both series and parallel.