Positive electrode active material, positive electrode using the same and non-aqueous electrolyte secondary battery

Abstract

A positive electrode active material includes: a particle containing a positive electrode material capable of intercalating and deintercalating an electrode reactant; and a film provided in at least a part of the particle and having a peak of C 2 H 5 S + , C 3 H 7 S + or C 4 H 9 S + obtained by cation analysis by time of flight secondary ion mass spectrometry.

The application is claimed as follows: 
     
         1 . A non-aqueous electrolyte secondary battery comprising:
 a positive electrode having a positive electrode active material;   a negative electrode;   a separator; and   an electrolyte, wherein   the positive electrode active material includes   a particle containing a positive electrode material capable of intercalating and deintercalating an electrode reactant; and   a film provided in at least a part of the particle wherein   a film having a peak of C 2 H 5 S + , C 3 H 7 S +  or C 4 H 9 S +  obtained by cation analysis by time of flight secondary ion mass spectrometry, and wherein   an upper limit discharge voltage is 4.35 V or more and not more than 4.80 V.   
     
     
         2 . The non-aqueous electrolyte secondary battery according to  claim 1 , wherein the particle includes at least lithium and one or more transition metal elements. 
     
     
         3 . The non-aqueous electrolyte secondary battery according to  claim 2 , wherein the particle includes cobalt (Co) as a principal transition metal element and has a layered structure. 
     
     
         4 . The non-aqueous electrolyte secondary battery according to  claim 3 , wherein one or more elements different from the principal transition metal element care included in at least a part of the surface of the particle. 
     
     
         5 . The non-aqueous electrolyte secondary battery according to  claim 4 , wherein the one or more elements include at least one of nickel (Ni), manganese (Mn) and phosphorus (P). 
     
     
         6 . The non-aqueous electrolyte secondary battery according to  claim 4 , wherein the one or more elements include manganese (Mn) and any one of nickel (Ni) and phosphorus (P). 
     
     
         7 . The non-aqueous electrolyte secondary battery according to  claim 1 , wherein a lower limit discharge voltage is 2.00 V or more and not more than 3.30 V. 
     
     
         8 . The non-aqueous electrolyte secondary battery according to  claim 1 , wherein an average particle size of the positive electrode active material is 2.0 μm or more and not more than 50 μm. 
     
     
         9 . A method for preparing a non-aqueous electrolyte secondary battery including a positive electrode having a positive electrode active material, a negative electrode, a separator, and an electrolyte, the positive electrode active material including a particle containing a positive electrode material capable of intercalating and deintercalating an electrode reactant, at least a part of the particle being provided with a film having a peak of C 2 H 5 S + , C 3 H 7 S +  or C 4 H 9 S +  obtained by cation analysis by time of flight secondary ion mass spectrometry, the method comprising:
 forming the film on at least a part of the particle by using the compound expressed by the formula (1) 
 
       
         
           
           
               
               
           
         
         wherein R1 and R2 each represents a hydrogen group or a hydrocarbon group, provided that R1 and R2 may be bonded to each other to form a cyclic structure; and a1 and b1 each represents an integer of 1 or more. 
       
     
     
         10 . The method according to  claim 9 , wherein the particle includes at least lithium and one or more transition metal elements. 
     
     
         11 . The method according to  claim 10 , wherein the particle contains cobalt (Co) as a principal transition metal element and has a layered structure. 
     
     
         12 . The method according to  claim 11 , wherein one or more elements different from the principal transition metal element are included in at least a part of the surface of the particle. 
     
     
         13 . The method according to  claim 12 , wherein the one or more elements include at least one of nickel (Ni), manganese (Mn) and phosphorus (P). 
     
     
         14 . The method according to  claim 12 , wherein the one or more elements include manganese (Mn) and any one of nickel (Ni) and phosphorus (P). 
     
     
         15 . The method according to  claim 9 , wherein a lower limit discharge voltage is 2.00 V or more and not more than 3.30 V. 
     
     
         16 . The method according to  claim 9 , wherein an average particle size of the positive electrode active material is 2.0 μm or more and not more than 50 μm.