Lithium secondary batteries with positive eletrode compositions and their methods of manufacturing

Abstract

Positive electrodes for secondary batteries formed with a plurality of substantially aligned flakes within a coating. The flakes can be formed from metal oxide materials and have a number average longest dimension of greater than 60 μm. A variety of metal oxide or metal phosphate materials may be selected such as a group consisting of LiCoO 2 , LiMn 2 O 4 , Li(M1 x1 M2 x2 Co 1-x1-x2 )O 2 where M1 and M2 are selected from among Li, Ni, Mn, Cr, Ti, Mg, or Al, 0≤x1≤0.5 and 0≤x2≤0.5, or alternatively, LiM1 (1-x) Mn x O 2 where 0<x<0.8 and M1 represents one or more metal elements. Methods for making positive electrode materials are also provided involving the formation of structures with a desired longest dimension, preferably polycrystalline flakes. A cathode coating containing polycrystalline flakes may be deposited onto a conductive substrate and pressed to a desired final electrode thickness.

What is claimed is: 
     
         1 . A secondary battery having an electrode comprising a conductive substrate coated with a plurality of flakes that have a number average longest dimension greater than 60 said flakes further comprising individual primary or intermediate secondary particles formed of a metal oxide or metal phosphate material. 
     
     
         2 . The secondary battery of  claim 1 , wherein the plurality of flakes are aligned to form a cathode coating that is at least 30 μm thick. 
     
     
         3 . The secondary battery of  claim 1 , wherein the flakes have a shortest dimension of about 17 μm or 25 μm. 
     
     
         4 . The secondary battery of  claim 1 , further comprising a filler for filling in spaces or voids between the plurality of flakes, said filler comprising a powder with average particle size less than about 17 μm in any direction. 
     
     
         5 . The secondary battery of  claim 4 , wherein the filler consists of a metal oxide or a metal phosphate material or a combination of metal oxide and metal phosphate materials. 
     
     
         6 . The secondary battery of  claim 1 , wherein the metal oxide material is selected from the group consisting of LiCoO 2 , Li(Mn 1-x3 M3 x3 ) 2 O 4 , Li(M1 x1 M2 x2 Co 1-x1-x2 )O 2  where M1 and M2 are selected from among Li, Ni, Mn, Cr, Ti, Mg, or Al, M3 is selected from one or a combination of Li, Ni, Co, Cr, Ti, Mg, or Al, ≤x1≤0.5, 0≤x2≤0.5 and 0≤x3≤0.5. 
     
     
         7 . The secondary battery of  claim 1 , wherein the metal oxide material is LiM1 (1-x) Mn x O 2  where 0<x<0.8 and M1 represents one or more metal elements. 
     
     
         8 . The secondary battery of  claim 7 , wherein M1 includes nickel, cobalt or a combination thereof. 
     
     
         9 . The secondary battery of  claim 7 , wherein the metal oxide is LiNi 0.33 Co 0.33 Mn 0.33 O 2  (NMC). 
     
     
         10 . The secondary battery of  claim 7 , wherein the metal phosphate material is described by the formula LiMPO 4 , where M is selected from one or a combination of Fe, Mn, Ni or Co. 
     
     
         11 . A secondary battery having an electrode comprising a conductive substrate coated with a plurality of polycrystalline or monocrystalline flakes of one or more metal oxide or metal phosphate materials, wherein the flakes have a longest dimension of greater than 60 μm and further comprising individual primary or intermediate secondary particles formed of a metal oxide or metal phosphate material. 
     
     
         12 . The secondary battery of  claim 11 , wherein the flakes have a shortest dimension of about 17 μm or 25 μm. 
     
     
         13 . The secondary battery of  claim 11 , wherein the metal oxide material is selected from the group consisting of LiCoO 2 , Li(Mn 1-x3 M3 x3 ) 2 O 4 , Li(M1 x1 M2 x2 Co 1-x1-x2 )O 2  where M1 and M2 are selected from among Li, Ni, Mn, Cr, Ti, Mg, or Al, M3 is selected from one or a combination of Li, Ni, Co, Cr, Ti, Mg, or Al, ≤x1≤0.5, 0≤x2<0.5 and 0≤x3≤0.5. 
     
     
         14 . The secondary battery of  claim 11 , wherein the metal phosphate material is defined by the formula LiMPO 4  where M is selected from one of or a combination of Fe, Mn, Ni or Co. 
     
     
         15 . The secondary battery of  claim 11 , wherein the metal oxide material is LiM1 (1-x) Mn x O 2  where 0<x<0.5 and M1 represents one or more metal elements. 
     
     
         16 . A positive electrode material comprising a plurality of flakes that have a longest dimension greater than 100 μm of a metal oxide or metal phosphate material. 
     
     
         17 . The positive electrode material of  claim 16 , wherein the metal oxide material is selected from the group consisting of LiCoO 2 , Li(Mn 1-x3 M3 x3 ) 2 O 4 , Li(M1 x1 M2 x2 Co 1-x1-x2 )O 2  where M1 and M2 are selected from among Li, Ni, Mn, Cr, Ti, Mg, or Al, M3 is selected from one or a combination of Li, Ni, Co, Cr, Ti, Mg, or Al, ≤x1≤0.5, 0≤x2≤0.5 and 0≤x3≤0.5. 
     
     
         18 . The positive electrode material of  claim 16 , wherein the metal oxide material is LiM1 (1-x) Mn x O 2  where 0<x<0.5 and M1 represents one or more metal elements. 
     
     
         19 . The positive electrode material of  claim 16 , wherein the metal phosphate material is defined by the formula LiMPO 4 , where M is selected from one of or a combination of Fe, Mn, Ni, or Co.