Method of manufacturing electrode

Abstract

To increase the conductivity and electric capacity of an electrode which includes active material particles and the like and is used in a battery, a graphene net including 1 to 100 graphene sheets is used instead of a conventionally used conduction auxiliary agent and binder. The graphene net which has a two-dimensional expansion and a three-dimensional structure is more likely to touch active material particles or another conduction auxiliary agent, thereby increasing the conductivity and the bonding strength between active material particles. This graphene net is obtained by mixing graphene oxide and active material particles and then heating the mixture in a vacuum or a reducing atmosphere.

1 . An electrode comprising:
 an active material layer comprising:
 active material particles with an average primary particle size of 20 nm to 100 nm; and 
   a carbon material which is a one-atom-thick sheet of a carbon molecule having sp 2  bonds or a stack of less than 100 sheets of the one-atom-thick sheets,   wherein the active material particles comprises oxygen atoms, and   wherein a weight ratio of the active material particles to the active material layer is 95% or higher.   
     
     
         2 . The electrode according to  claim 1 , wherein the weight ratio of the active material particles to the active material layer is 97% or higher. 
     
     
         3 . The electrode according to  claim 1 , wherein the active material layer does not comprise a polymer organic compound. 
     
     
         4 . The electrode according to  claim 1 , wherein each surface of the active material particles is coated with a conductive film comprising carbon. 
     
     
         5 . The electrode according to  claim 1 , wherein a material of the active material particles is lithium iron phosphate. 
     
     
         6 . An power storage device comprising the electrode according to  claim 1 , a counter electrode and an electrolyte. 
     
     
         7 . An electric appliance comprising the power storage device according to  claim 6 . 
     
     
         8 . An electrode comprising:
 an active material layer comprising:
 active material particles with an average primary particle size of 20 nm to 100 nm; and 
 a piece of graphene as a 1 to 100 carbon sheets, 
   wherein a material of the active material particles is a positive electrode active material comprising an oxygen atom, and   wherein a weight ratio of the active material particles to the active material layer is 95% or higher.   
     
     
         9 . The electrode according to  claim 8 , wherein the weight ratio of the active material particles to the active material layer is 97% or higher. 
     
     
         10 . The electrode according to  claim 8 , wherein the active material layer does not comprise a polymer organic compound. 
     
     
         11 . The electrode according to  claim 8 , wherein each surface of the active material particles is coated with a conductive film comprising carbon. 
     
     
         12 . The electrode according to  claim 8 , wherein the material of the active material particles is lithium iron phosphate. 
     
     
         13 . An power storage device comprising the electrode according to  claim 8 , a counter electrode and an electrolyte. 
     
     
         14 . An electrode comprising:
 an active material layer comprising:
 active material particles with an average primary particle size of 20 nm to 100 nm; 
 a first piece of graphene as a 1 to 100 carbon sheets; and 
 a second piece of graphene as a 1 to 100 carbon sheets, 
   wherein a material of the active material particles comprises an oxygen atom,   wherein a first particle of the active material particles is covered with the first piece of graphene,   wherein a second particle of the active material particles is covered with the second piece of graphene,   wherein a weight ratio of the active material particles to the active material layer is 95% or higher, and   wherein the first piece of graphene has bonds of the second piece of graphene at a plurality of portions of the first piece of graphene.   
     
     
         15 . The electrode according to  claim 14 , wherein the weight ratio of the active material particles to the active material layer is 97% or higher. 
     
     
         16 . The electrode according to  claim 14 , wherein the active material layer does not comprise a polymer organic compound. 
     
     
         17 . The electrode according to  claim 14 , wherein each surface of the active material particles is coated with a conductive film comprising carbon. 
     
     
         18 . An power storage device comprising the electrode according to  claim 14 , a counter electrode and an electrolyte.