Positive electrode plate of lithium ion secondary battery, lithium ion secondary battery, and method of producing positive electrode plate of lithium ion secondary battery

Abstract

A positive electrode plate of a lithium ion secondary battery includes a current collector foil, an active material layer including positive electrode active material particles containing lithium oxide on the current collector foil, and a protective conductive layer that does not include the positive electrode active material particles and includes a conductive material and a binding agent on the active material layer.

What is claimed is: 
     
         1 . A positive electrode plate of a lithium ion secondary battery comprising:
 a current collector foil;   an active material layer including positive electrode active material particles containing lithium oxide on the current collector foil; and   a protective conductive layer that does not include the positive electrode active material particles and includes a conductive material and a binding agent on the active material layer.   
     
     
         2 . The positive electrode plate of a lithium ion secondary battery according to  claim 1 , wherein the protective conductive layer includes a moisture absorbent. 
     
     
         3 . The positive electrode plate of a lithium ion secondary battery according to  claim 2 , wherein the moisture absorbent is a chemical moisture absorbent that adsorbs water through a chemical reaction. 
     
     
         4 . The positive electrode plate of a lithium ion secondary battery according to  claim 3 , wherein the moisture absorbent is an anhydrite powder. 
     
     
         5 . The positive electrode plate of a lithium ion secondary battery according to  claim 1 , wherein the positive electrode active material particles included in the active material layer have a property in which a pH of a liquid dispersion in which 1 g of the positive electrode active material particles is dispersed in 49 g of water is 11.3 or more. 
     
     
         6 . The positive electrode plate of a lithium ion secondary battery according to  claim 1 , wherein a layer thickness of the protective conductive layer is thinner than a layer thickness of the active material layer. 
     
     
         7 . The positive electrode plate of a lithium ion secondary battery according to  claim 6 , wherein the layer thickness of the protective conductive layer is 2 μm or more. 
     
     
         8 . A lithium ion secondary battery comprising:
 the positive electrode plate according to  claim 1 ; and   a negative electrode plate.   
     
     
         9 . A method of producing a positive electrode plate of a lithium ion secondary battery comprising:
 forming an undried active material layer including positive electrode active material particles containing lithium oxide on a current collector foil;   forming an undried protective conductive layer that does not include the positive electrode active material particles and includes a conductive material and a binding agent on the undried active material layer; and   drying the undried active material layer and the undried protective conductive layer simultaneously and forming an active material layer and a protective conductive layer.