Electrode and battery

Abstract

In this disclosure, a battery is provided. The electrode includes an electrode current collector and an electrode active material layer, wherein the electrode active material layer includes a single crystal electrode active material and a polycrystalline electrode active material, and the single crystal electrode active material and the polycrystalline electrode active material are each a lithium transition metal composite oxide, and the electrode active material layer includes a first layer including a first surface opposite to the electrode current collector and a second layer including a second surface on the electrode current collector side, wherein the first layer includes the single crystal electrode active material as a main component of the electrode active material, and the second layer includes the polycrystalline electrode active material as a main component of the electrode active material.

What is claimed is: 
     
         1 . An electrode that is used in a battery, the electrode comprising:
 an electrode current collector; and   an electrode active material layer,   wherein the electrode active material layer contains a single crystal electrode active material and a polycrystalline electrode active material as electrode active materials,   wherein the single crystal electrode active material and the polycrystalline electrode active material are lithium transition metal composite oxides,   wherein the electrode active material layer includes a first layer including a first surface on an opposite side from the electrode current collector, and a second layer including a second surface on the electrode current collector side,   wherein the first layer contains the single crystal electrode active material as a main component of the electrode active material, and   wherein the second layer contains the polycrystalline electrode active material as a main component of the electrode active material.   
     
     
         2 . The electrode according to  claim 1 , wherein the single crystal electrode active material and the polycrystalline electrode active material each contain at least one of Ni, Co, and Mn as a transition metal. 
     
     
         3 . The electrode according to  claim 1 , wherein a constituent element constituting the single crystal electrode active material and a constituent element constituting the polycrystalline electrode active material are the same. 
     
     
         4 . The electrode according to  claim 1 , wherein the first layer contains the polycrystalline electrode active material. 
     
     
         5 . The electrode according to  claim 1 , wherein the first layer does not contain the polycrystalline electrode active material. 
     
     
         6 . The electrode according to  claim 1 , wherein the second layer contains the single crystal electrode active material. 
     
     
         7 . The electrode according to  claim 1 , wherein the second layer does not contain the single crystal electrode active material. 
     
     
         8 . The electrode according to  claim 1 ,
 wherein the first layer contains a first composite in which a fibrous carbon material is adhered to a surface of the single crystal electrode active material, and   wherein the second layer contains a second composite in which a particulate carbon material is adhered to a surface of the polycrystalline electrode active material.   
     
     
         9 . The electrode according to  claim 8 , wherein the fibrous carbon material is a carbon nanotube and the particulate carbon material is carbon black. 
     
     
         10 . The electrode according to  claim 1 , wherein the electrode is a positive electrode. 
     
     
         11 . A battery comprising:
 a positive electrode;   a negative electrode; and   an electrolyte layer disposed between the positive electrode and the negative electrode,   wherein at least one of the positive electrode and the negative electrode is the electrode according to  claim 1 .