Electrode, manufacturing method thereof, storage battery, and electronic device

Abstract

As a positive electrode active material of a secondary battery, a lithium-manganese composite oxide containing lithium, manganese, and an element represented by M, and oxygen is used, and the lithium-manganese composite oxide is covered with reduced graphene oxide. An active material layer including the active material, graphene oxide, a conductive additive, and a binder is formed and soaked in alcohol, and then heat treatment is performed, whereby an electrode with reduced graphene oxide is fabricated.

What is claimed is: 
     
         1 . A method for manufacturing an electrode, comprising:
 forming an active material layer over a current collector; and   performing heat treatment on the active material layer after the active material layer is impregnated with alcohol,   wherein the active material layer includes an active material particle covered with a film containing carbon, a conductive additive, graphene oxide, and a binder.   
     
     
         2 . A method for manufacturing an electrode, comprising:
 forming an active material layer over a current collector; and   performing heat treatment on the active material layer after the active material layer is impregnated with alcohol,   wherein the active material layer includes an active material particle covered with a film containing carbon, a conductive additive, graphene oxide, and a binder, and   wherein the film containing carbon includes reduced graphene oxide.   
     
     
         3 . The method for manufacturing an electrode, according to  claim 1 ,
 wherein the active material particle is a lithium-manganese composite oxide represented by Li a Mn b M c O d , and   wherein the element M is any one of chromium, cobalt, aluminum, nickel, iron, magnesium, molybdenum, zinc, indium, gallium, copper, titanium, niobium, silicon, and phosphorus.   
     
     
         4 . The method for manufacturing an electrode, according to  claim 1 ,
 wherein the alcohol is any one of methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, and tert-butyl alcohol.   
     
     
         5 . An electrode comprising:
 a current collector; and   an active material layer over the current collector,   wherein the active material layer comprises:
 an active material particle; 
 a conductive additive; 
 first reduced graphene oxide; 
 second reduced graphene oxide; and 
 a binder, 
   wherein the first reduced graphene oxide is in contact with a first region of the active material particle, and   wherein the second reduced graphene oxide is in contact with a second region of the active material particle and includes a region covering at least part of the first reduced graphene oxide.   
     
     
         6 . The electrode according to  claim 5 ,
 wherein the active material particle is a lithium-manganese composite oxide represented by Li a Mn b M c O d , and   wherein the element M is any one of chromium, cobalt, aluminum, nickel, iron, magnesium, molybdenum, zinc, indium, gallium, copper, titanium, niobium, silicon, and phosphorus.   
     
     
         7 . A storage battery comprising:
 the electrode according to  claim 5 ; and   a negative electrode.   
     
     
         8 . An electronic device comprising:
 the storage battery according to  claim 7 ; and   a display panel, an operation key, a speaker, or a microphone.