Anode and battery

Abstract

A battery including a cathode, an anode, and an electrolytic solution. The electrolytic solution is impregnated in a separator provided between the cathode and the anode. The anode has an insulative coat on an anode active material layer provided on an anode current collector. The coat contains an insulating material such as a meal hydroxide and a metal oxide. The coat is in a form of plate divided into a plurality of portions. The insulation property of the coat prevents internal short circuit. A plurality of portions of the coat prevent separation of the anode active material layer and decomposition of the electrolytic solution. Further, even when short circuit occurs, heat generation is prevented by heat absorption characteristics of the coat.

What is claimed is: 
     
         1 . An anode comprising:
 an anode current collector;   an active material layer on the anode current collector; and   an insulative coat on the anode active material layer,   wherein,
 the insulative coat is divided into a plurality of spaced apart portions across an outer surface of the anode active material layer and is configured to provide a migration path for an electrode reactant to the active material layer between the portions, 
 the anode active material layer contains a plurality of anode active material particles, and 
 the coat extends along a partial surface of two or more of the anode active material particles while continuously covering the partial surface. 
   
     
     
         2 . The anode according to  claim 1 , wherein the insulative coat is in the form of a plate. 
     
     
         3 . The anode according to  claim 1 , wherein the insulative coat is formed by electrolytic plating method. 
     
     
         4 . The anode according to  claim 1 , wherein the anode active material layer contains a plurality of anode active material particles containing silicon. 
     
     
         5 . The anode according to  claim 1 , wherein where an area of the anode active material layer is S1 and an area of the insulative coat is S2, and an area ratio S2/S1 is in the range from 0.2 to 0.9, inclusive. 
     
     
         6 . The anode according to  claim 1 , wherein a weight per unit area of the insulative coat is in the range from 0.02 mg/cm2 to 1 mg/cm2, inclusive. 
     
     
         7 . A battery comprising:
 a cathode;   an anode; and   an electrolytic solution,   wherein,
 the insulative coat is divided into a plurality of spaced apart portions across an outer surface of the anode active material layer and is configured to provide a migration path for an electrode reactant to the active material layer between the portions, 
 the anode active material layer contains a plurality of anode active material particles, and 
 the coat extends along a partial surface of two or more of the anode active material particles while continuously covering the partial surface. 
   
     
     
         8 . The battery according to  claim 7 , wherein the insulative coat is in the form of a plate. 
     
     
         9 . The battery according to  claim 7 , wherein the insulative coat is formed by electrolytic plating method. 
     
     
         10 . The battery according to  claim 7 , wherein the anode active material layer contains a plurality of anode active material particles containing silicon. 
     
     
         11 . The battery according to  claim 7 , wherein where an area of the anode active material layer is S1 and an area of the coat is S2, and an area ratio S2/S1 is in the range from 0.2 to 0.9, inclusive. 
     
     
         12 . The battery according to  claim 7 , wherein a weight per unit area of the coat is in the range from 0.02 mg/cm2 to 1 mg/cm2, inclusive.