Lithium Battery Electrodes

Abstract

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.

Embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
         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 the aqueous acidic solution has a pH of in the range of about 4 to about 7; and the first lithium metal oxide material in step (a) is a compound with a layered structure, a spinel structure, a rock salt structure, a blend of two or more of the foregoing structures, or a structurally-integrated composite of two or more of the forgoing structures.   
     
     
         2 . 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. 
     
     
         3 . The electrode of  claim 1 , wherein the temperature in step (b) is less than 150° C. 
     
     
         4 . The electrode of  claim 1 , wherein the temperature in step (b) is less than 120° C. 
     
     
         5 . The electrode of  claim 1 , wherein the temperature in step (b) is 100° C. or less. 
     
     
         6 . The electrode of  claim 1 , wherein the metal cations in the aqueous acidic solution comprise one or more metal cations selected from the group consisting of aluminum ion, magnesium ion, cobalt ion, and nickel ion. 
     
     
         7 . The electrode of  claim 1 , wherein the metal cations in the aqueous acidic solution comprise one or more metal cations selected from the group consisting of zirconium and aluminum ions. 
     
     
         8 . The electrode of  claim 1 , wherein the aqueous acidic solution is an acidic nitrate solution comprising the one or more metal cations. 
     
     
         9 . The electrode of  claim 8 , wherein the acidic nitrate solution comprises aluminum nitrate, zirconium nitrate, or a combination thereof. 
     
     
         10 . The electrode of  claim 1 , wherein the first lithium metal oxide material comprises LiNi 0.4 Mn 0.4 Co 0.2 O 2 . 
     
     
         11 . The electrode of  claim 1 , wherein the first lithium metal oxide material comprises LiCo 1−x Ni x O 2  wherein 0≤x<0.5. 
     
     
         12 . The electrode of  claim 1 , wherein the first lithium metal oxide material comprises layered Li z MO (z+1) , wherein z is 1 or 2, and M is one or more of Mn, Ni and Co. 
     
     
         13 . The electrode of  claim 1 , wherein the first lithium metal oxide material comprises a spinel of formula Li[M″ 2 ]O 4 , wherein M″ is one or more metal ions. 
     
     
         14 . The electrode of  claim 1 , wherein the first lithium metal oxide material comprises Li 1+n Mn 2−n O 4 , wherein 0≤n≤0.33. 
     
     
         15 . The electrode of  claim 1 , wherein the first lithium metal oxide material comprises a lithiated spinel of formula Li 2 [M″ 2 ]O 4 , wherein M″ is one or more of Mn, Co, and Ti. 
     
     
         16 . 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 . 
     
     
         17 . The electrochemical cell of  claim 16 , wherein the electrolyte comprises up to about 1 percent by weight of lithium difluoro(oxalate)borate (LiDFOB). 
     
     
         18 . The electrochemical cell of  claim 17 , wherein the electrolyte comprises about 0.01 to about 1 wt %; or 0.05 to about 0.75 wt % LiDFOB. 
     
     
         19 . The electrochemical cell of  claim 17 , wherein the electrolyte comprises about 0.1 to about 0.5 wt % of LiDFOB. 
     
     
         20 . A battery containing more than one electrochemical cell of  claim 16 , connected in series, in parallel, or in both series and parallel.