Positive-electrode active material and battery

Abstract

A positive-electrode active material contains a compound that has a crystal structure belonging to a space group FM3-M and that is represented by the composition formula (1): Li x A y Me z O α F β   (1) wherein A denotes Na or K, Me denotes one or two or more elements selected from the group consisting of Mn, Co, Ni, Fe, Al, B, Ce, Si, Zr, Nb, Pr, Ti, W, Ge, Mo, Sn, Bi, Cu, Mg, Ca, Ba, Sr, Y, Zn, Ga, Er, La, Sm, Yb, V, and Cr, and the following conditions are satisfied. 1.7≤x+y≤2.2 0<y≤0.2 0.8≤z≤1.3 1≤α≤2.5 0.5≤β≤2

What is claimed is: 
     
         1 . A positive-electrode active material comprising a compound that has a crystal structure belonging to a space group FM3-M and is represented by the composition formula (1):
   Li x A y Me z O α F β   (1)
   wherein A denotes Na or K,   Me denotes one or two or more elements selected from the group consisting of Mn, Co, Ni, Fe, Al, B, Ce, Si, Zr, Nb, Pr, Ti, W, Ge, Mo, Sn, Bi, Cu, Mg, Ca, Ba, Sr, Y, Zn, Ga, Er, La, Sm, Yb, V, and Cr, and the following conditions are satisfied.   1.7≤x+y≤2.2   0<y≤0.2   0.8≤z≤1.3   1≤α≤2.5   0.5≤β≤2   
     
     
         2 . The positive-electrode active material according to  claim 1 , containing the compound as a main component. 
     
     
         3 . The positive-electrode active material according to  claim 1 , satisfying x+y+z=α+β=3. 
     
     
         4 . The positive-electrode active material according to  claim 1 , wherein Me denotes one element selected from Mn and Co. 
     
     
         5 . The positive-electrode active material according to  claim 1 , satisfying 0<y≤0.1. 
     
     
         6 . The positive-electrode active material according to  claim 1 , satisfying 1.8≤x≤1.99, and 0.01≤y≤0.2. 
     
     
         7 . The positive-electrode active material according to  claim 1 , satisfying z=1, α=2, and β=1. 
     
     
         8 . A battery comprising:
 a positive electrode containing the positive-electrode active material according to  claim 1 ;   a negative electrode; and   an electrolyte.   
     
     
         9 . The battery according to  claim 8 , wherein
 the negative electrode contains a negative-electrode active material with lithium adsorption and desorption characteristics, and the electrolyte is a non-aqueous electrolyte solution.