Graphene oxide, positive electrode for nonaqueous secondary battery using graphene oxide, method of manufacturing positive electrode for nonaqueous secondary battery, nonaqueous secondary battery, and electronic device

Abstract

A graphene oxide used as a raw material of a conductive additive for forming an active material layer with high electron conductivity with a small amount of a conductive additive is provided. A positive electrode for a nonaqueous secondary battery using the graphene oxide as a conductive additive is provided. The graphene oxide is used as a raw material of a conductive additive in a positive electrode for a nonaqueous secondary battery and, in the graphene oxide, the atomic ratio of oxygen to carbon is greater than or equal to 0.405.

1 . (canceled) 
     
     
         2 . A method for manufacturing a positive electrode for a nonaqueous secondary battery comprising multilayer graphene, comprising the step of:
 adding a positive electrode active material to a dispersion medium to form a first mixture;   kneading the first mixture to form a second mixture;   adding a binder to the second mixture;   applying a paste adding the binder on a positive electrode current collector; and   heating the positive electrode current collector applying the paste at a temperature higher than or equal to 130° C. and lower than or equal to 200° C.,   wherein the dispersion medium comprising carbon material, and   wherein the binder is configured to bind the positive electrode active material and the multilayer graphene.   
     
     
         3 . The method for manufacturing a positive electrode for a nonaqueous secondary battery comprising multilayer graphene, according to  claim 2 ,
 wherein graphene oxide is dispersed in the dispersion medium before adding the positive electrode active material, and   wherein the graphene oxide is reduced by the step of heating and the multilayer graphene is formed.   
     
     
         4 . The method for manufacturing a positive electrode for a nonaqueous secondary battery comprising multilayer graphene, according to  claim 2 , wherein a length of one side of the multilayer graphene is greater or equal to 50 nm and less than or equal to 100 μm. 
     
     
         5 . The method for manufacturing a positive electrode for a nonaqueous secondary battery comprising multilayer graphene, according to  claim 2 , wherein a length of one side of the multilayer graphene is larger than an average particle diameter of the positive electrode active material. 
     
     
         6 . The method for manufacturing a positive electrode for a nonaqueous secondary battery comprising multilayer graphene, according to  claim 2 , wherein the binder comprises any one of polyvinylidene fluoride, polyimide, poly-tetrafluoroethylene, polyvinyl chloride, ethylene-propylenediene polymer, styrene-butadiene rubber, acrylonitrile-butadiene rubber, fluorine rubber, polyvinyl acetate, polymethyl methacrylate, polyethylene, and nitrocellulose. 
     
     
         7 . A method for manufacturing a positive electrode for a nonaqueous secondary battery comprising multilayer graphene and a composite oxide containing nickel, manganese, and cobalt, comprising the step of:
 adding a positive electrode active material comprising the composite oxide to a dispersion medium to form a first mixture;   kneading the first mixture to form a second mixture;   adding a binder to the second mixture;   applying a paste adding the binder on a positive electrode current collector; and   heating the positive electrode current collector applying the paste at a temperature higher than or equal to 130° C. and lower than or equal to 200° C.,   wherein the dispersion medium comprising carbon material, and   wherein the binder is configured to bind the positive electrode active material and the multilayer graphene.   
     
     
         8 . The method for manufacturing a positive electrode for a nonaqueous secondary battery comprising multilayer graphene, according to  claim 7 ,
 wherein graphene oxide is dispersed in the dispersion medium before adding the positive electrode active material, and   wherein the graphene oxide is reduced by the step of heating and the multilayer graphene is formed.   
     
     
         9 . The method for manufacturing a positive electrode for a nonaqueous secondary battery comprising multilayer graphene, according to  claim 7 , wherein a length of one side of the multilayer graphene is greater or equal to 50 nm and less than or equal to 100 μm. 
     
     
         10 . The method for manufacturing a positive electrode for a nonaqueous secondary battery comprising multilayer graphene, according to  claim 7 , wherein a length of one side of the multilayer graphene is larger than an average particle diameter of the positive electrode active material. 
     
     
         11 . The method for manufacturing a positive electrode for a nonaqueous secondary battery comprising multilayer graphene, according to  claim 7 , wherein the binder comprises any one of polyvinylidene fluoride, polyimide, poly-tetrafluoroethylene, polyvinyl chloride, ethylene-propylenediene polymer, styrene-butadiene rubber, acrylonitrile-butadiene rubber, fluorine rubber, polyvinyl acetate, polymethyl methacrylate, polyethylene, and nitrocellulose. 
     
     
         12 . A method for manufacturing a positive electrode for a nonaqueous secondary battery comprising multilayer graphene and a composite oxide containing nickel, manganese, and cobalt, comprising the step of:
 adding a positive electrode active material comprising the composite oxide to a dispersion medium to form a first mixture;   kneading the first mixture to form a second mixture;   adding a binder to the second mixture;   applying a paste adding the binder on a positive electrode current collector; and   heating the positive electrode current collector applying the paste at a temperature higher than or equal to 130° C. and lower than or equal to 200° C.,   wherein the dispersion medium comprising carbon material,   wherein the positive electrode active material is added at greater than or equal to 85 wt % and less than or equal to 93 wt % with respect to total weight of the paste. wherein the binder is configured to bind the positive electrode active material and the multilayer graphene.   
     
     
         13 . The method for manufacturing a positive electrode for a nonaqueous secondary battery comprising multilayer graphene, according to  claim 12 ,
 wherein graphene oxide is dispersed in the dispersion medium before adding the positive electrode active material, and   wherein the graphene oxide is reduced by the step of heating and the multilayer graphene is formed.   
     
     
         14 . The method for manufacturing a positive electrode for a nonaqueous secondary battery comprising multilayer graphene, according to  claim 12 , wherein a length of one side of the multilayer graphene is greater or equal to 50 nm and less than or equal to 100 μm. 
     
     
         15 . The method for manufacturing a positive electrode for a nonaqueous secondary battery comprising multilayer graphene, according to  claim 12 , wherein a length of one side of the multilayer graphene is larger than an average particle diameter of the positive electrode active material. 
     
     
         16 . The method for manufacturing a positive electrode for a nonaqueous secondary battery comprising multilayer graphene, according to  claim 12 , wherein the binder comprises any one of polyvinylidene fluoride, polyimide, poly-tetrafluoroethylene, polyvinyl chloride, ethylene-propylenediene polymer, styrene-butadiene rubber, acrylonitrile-butadiene rubber, fluorine rubber, polyvinyl acetate, polymethyl methacrylate, polyethylene, and nitrocellulose.