Cathode active material and non-aqueous electrolyte cell

Abstract

There is provided a non-aqueous electrolyte cell having a high capacity and superior in cyclic characteristics. Specifically, there is provided a non-aqueous electrolyte cell including a cathode 2 containing a cathode/positive active material, an anode 3 containing an anode/negative active material and a non-aqueous electrolyte, wherein the cathode/positive active material contains a lithium nickel composite oxide represented by the general formula Li A Ni 1−Z M Z O 2 , where A is such that 0.95≦A<1, Z is such that 0.01≦Z≦0.5 and M is at least one of Fe, Co, Mn, Cu, Zn, Al, Sn, B, Ga, Cr, V, Ti, Mg, Ca and Sr.

What is claimed is:  
     
         1 . A cathode/positive active material containing a lithium nickel composite oxide represented by the general formula Li A Ni 1−Z M Z O 2 , where A is such that 0.95≦A<1, Z is such that 0.01≦Z<0.5 and M is at least one of Fe, Co, Mn, Cu, Zn, Al, Sn, B, Ga, Cr, V, Ti, Mg, Ca and Sr.  
     
     
         2 . The cathode/positive active material according to  claim 1  wherein A of the general formula is such that 0.97≦A<0.995.  
     
     
         3 . The cathode/positive active material according to  claim 1  containing a lithium manganese composite oxide.  
     
     
         4 . The cathode/positive active material according to  claim 3  wherein said lithium manganese composite oxide is a compound represented by the general formula Li X Mn 2−Y M′ Y O 4 , where X is such that 0.9≦X, Y is such that 0.01≦Y≦0.5 and M′ is at least one of Fe, Co, Ni, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca and Sr.  
     
     
         5 . The cathode/positive active material according to  claim 3  wherein the lithium nickel composite oxide represented by the general formula Li A Ni 1−Z M Z O 2  and the lithium manganese composite oxide are mixed at a weight ratio of 20:80 to 80:20.  
     
     
         6 . A non-aqueous electrolyte cell including a cathode containing a cathode/positive active material, an anode containing an anode/negative active material and a non-aqueous electrolyte wherein the cathode/positive active material contains a lithium nickel composite oxide represented by the general formula Li A Ni 1−Z M Z O 2 , where A is such that 0.95≦A<1, Z is such that 0.01≦Z≦0.5 and M is at least one of Fe, Co, Mn, Cu, Zn, Al, Sn, B, Ga, Cr, V, Ti, Mg, Ca and Sr.  
     
     
         7 . The non-aqueous electrolyte cell according to  claim 6  wherein A of the general formula is such that 0.97≦A≦0.995.  
     
     
         8 . The non-aqueous electrolyte cell according to  claim 6  containing a lithium manganese composite oxide as said cathode/positive active material.  
     
     
         9 . The non-aqueous electrolyte secondary cell according to  claim 8  wherein said said lithium manganese composite oxide is a compound represented by the general formula Li X Mn 2−Y M′ Y O 4 , where X is such that 0.01≦X, Y is such that 0.01≦Y≦0.5 and M′ is at least one of Fe, Co, Ni, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca and Sr.  
     
     
         10 . The non-aqueous electrolyte secondary cell according to  claim 8  wherein 
 the lithium nickel composite oxide represented by the general formula Li A Ni 1−Z M Z O 2  and the lithium manganese composite oxide are mixed at a weight ratio of 20:80 to 80:20.  
 
     
     
         11 . The non-aqueous electrolyte secondary cell according to  claim 6  wherein 
 said anode uses, as an active material, one or more carbonaceous materials capable of doping and undoping lithium and which are selected from the group consisting of pyrocarbon, cokes, graphite, vitreous carbon, sintered organic high molecular or polymer compounds, carbon fibers and activated charcoal.  
 
     
     
         12 . The non-aqueous electrolyte secondary cell according to  claim 6  wherein 
 said anode is formed by spherical, flat or fiber-like graphite powders having the spacing of the ( 002 ) plane being 0.335 to 0.340 nm and the c-axis spacing Lc being not less than 20 nm.  
 
     
     
         13 . The non-aqueous electrolyte secondary cell according to  claim 6  wherein said cathode is formed by a current collector on each side of which is coated a layer of a mixture containing an active material, said anode is formed by a current collector on each side of which is coated a layer of a mixture containing an active material, said cathode and the anode being laminated together via a separator in-between to form a laminated product which then is spirally wound about itself a number of times to form an electrode unit.