Positive electrode active material particle and manufacturing method of positive electrode active material particle

Abstract

Provided is a positive electrode active material which suppresses a reduction in capacity due to charge and discharge cycles when used in a lithium ion secondary battery. A covering layer is formed by segregation on a superficial portion of the positive electrode active material. The positive electrode active material includes a first region and a second region. The first region exists in an inner portion of the positive electrode active material. The second region exists in a superficial portion of the positive electrode active material and part of the inner portion thereof. The first region includes lithium, a transition metal, and oxygen. The second region includes magnesium, fluorine, and oxygen.

1 . A battery comprising:
 a positive electrode comprising an active material particle comprising:
 a first region comprising cobalt and aluminum; and 
 a second region comprising cobalt, magnesium, and fluorine, 
   wherein the first region comprises a layered rock-salt crystal structure,   wherein the second region covers at least a part of the first region,   wherein a maximum peak of the magnesium in the active material particle exists in the second region,   wherein the first region comprises a first measurement region,   wherein the second region comprises a second measurement region, and   wherein a ratio of divalent cobalt atoms to all cobalt atoms in the second measurement region is higher than a ratio of divalent cobalt atoms to all cobalt atoms in the first measurement region.   
     
     
         2 . A battery comprising:
 a positive electrode comprising an active material particle comprising:
 a first region comprising cobalt and aluminum; and 
 a second region comprising cobalt, magnesium, and fluorine, 
   wherein the first region comprises a layered rock-salt crystal structure,   wherein the second region covers at least a part of the first region,   wherein a maximum peak of the magnesium in the active material particle exists in the second region, and   wherein an L 3 /L 2  of cobalt atoms in a second measurement region in the second region is larger than an L 3 /L 2  of cobalt atoms in a first measurement region in the first region in electron energy loss spectroscopy.   
     
     
         3 . A battery comprising:
 a positive electrode comprising an active material particle comprising:
 a first region comprising cobalt and aluminum; and 
 a second region comprising cobalt, magnesium, and fluorine, 
   wherein the first region comprises a layered rock-salt crystal structure,   wherein the second region covers at least a part of the first region,   wherein a maximum peak of the magnesium in the active material particle exists in the second region, and   wherein the second region comprises a measurement region, and the measurement region comprises divalent cobalt atoms.   
     
     
         4 . A battery comprising:
 a positive electrode comprising an active material particle comprising:
 a first region comprising cobalt and aluminum; and 
 a second region comprising cobalt, magnesium, and fluorine, 
   wherein the first region comprises a layered rock-salt crystal structure,   wherein the second region covers at least a part of the first region,   wherein a maximum peak of the magnesium in the active material particle exists in the second region, and   wherein cobalt atoms in a second measurement region in the second region are more reduced than cobalt atoms in a first measurement region in the first region.   
     
     
         5 . The battery according to  claim 1 ,
 wherein the second region comprises a rock-salt crystal structure, and   wherein a crystal orientation of at least a part of the first region and a crystal orientation of at least a part of the second region are substantially aligned with each other.   
     
     
         6 . The battery according to  claim 2 ,
 wherein the second region comprises a rock-salt crystal structure, and   wherein a crystal orientation of at least a part of the first region and a crystal orientation of at least a part of the second region are substantially aligned with each other.   
     
     
         7 . The battery according to  claim 3 ,
 wherein the second region comprises a rock-salt crystal structure, and   wherein a crystal orientation of at least a part of the first region and a crystal orientation of at least a part of the second region are substantially aligned with each other.   
     
     
         8 . The battery according to  claim 4 ,
 wherein the second region comprises a rock-salt crystal structure, and   wherein a crystal orientation of at least a part of the first region and a crystal orientation of at least a part of the second region are substantially aligned with each other.   
     
     
         9 . The battery according to  claim 1 ,
 wherein the second region comprises a crystal structure which is different from the layered rock-salt crystal structure, and   wherein a crystal orientation of at least a part of the first region and a crystal orientation of at least a part of the second region are substantially aligned with each other.   
     
     
         10 . The battery according to  claim 2 ,
 wherein the second region comprises a crystal structure which is different from the layered rock-salt crystal structure, and   wherein a crystal orientation of at least a part of the first region and a crystal orientation of at least a part of the second region are substantially aligned with each other.   
     
     
         11 . The battery according to  claim 3 ,
 wherein the second region comprises a crystal structure which is different from the layered rock-salt crystal structure, and   wherein a crystal orientation of at least a part of the first region and a crystal orientation of at least a part of the second region are substantially aligned with each other.   
     
     
         12 . The battery according to  claim 4 ,
 wherein the second region comprises a crystal structure which is different from the layered rock-salt crystal structure, and   wherein a crystal orientation of at least a part of the first region and a crystal orientation of at least a part of the second region are substantially aligned with each other.   
     
     
         13 . The battery according to  claim 1 ,
 wherein the maximum peak of the magnesium is measured by a line analysis of EDX.   
     
     
         14 . The battery according to  claim 2 ,
 wherein the maximum peak of the magnesium is measured by a line analysis of EDX.   
     
     
         15 . The battery according to  claim 3 ,
 wherein the maximum peak of the magnesium is measured by a line analysis of EDX.   
     
     
         16 . The battery according to  claim 4 ,
 wherein the maximum peak of the magnesium is measured by a line analysis of EDX.   
     
     
         17 . The battery according to  claim 1 ,
 wherein a maximum peak of the fluorine in the active material particle exists in the second region.   
     
     
         18 . The battery according to  claim 2 ,
 wherein a maximum peak of the fluorine in the active material particle exists in the second region.   
     
     
         19 . The battery according to  claim 3 ,
 wherein a maximum peak of the fluorine in the active material particle exists in the second region.   
     
     
         20 . The battery according to  claim 4 ,
 wherein a maximum peak of the fluorine in the active material particle exists in the second region.   
     
     
         21 . The battery according to  claim 1 ,
 wherein a thickness of the second region is less than or equal to 5 nm.   
     
     
         22 . The battery according to  claim 2 ,
 wherein a thickness of the second region is less than or equal to 5 nm.   
     
     
         23 . The battery according to  claim 3 ,
 wherein a thickness of the second region is less than or equal to 5 nm.   
     
     
         24 . The battery according to  claim 4 ,
 wherein a thickness of the second region is less than or equal to 5 nm.   
     
     
         25 . An electronic device comprising:
 the battery according to  claim 1 ; and   a circuit electrically connected to the battery,   wherein the circuit is configured to protect the battery from overcharge.   
     
     
         26 . An electronic device comprising:
 the battery according to  claim 2 ; and   a circuit electrically connected to the battery,   wherein the circuit is configured to protect the battery from overcharge.   
     
     
         27 . An electronic device comprising:
 the battery according to  claim 3 ; and   a circuit electrically connected to the battery,   wherein the circuit is configured to protect the battery from overcharge.   
     
     
         28 . An electronic device comprising:
 the battery according to  claim 4 ; and   a circuit electrically connected to the battery,   wherein the circuit is configured to protect the battery from overcharge.