Active material, manufacturing method for active material, and lithium ion secondary battery
View Patent ↗An active material having high capacity and excellent charging/discharging cycle durability at high potential is provided. The active material has a layered structure and is represented by the following composition formula (1): Li y Ni a Co b Mn c M d O x F z1 P z2 (1) wherein the element M is at least one element selected from the group consisting of Al, Si, Zr, Ti, Fe, Mg, Nb, Ba and V, and 1.9≦(a+b+c+d+y)≦2.1, 1.0≦y≦1.3, 0<a≦0.3, 0≦b≦0.25, 0.3≦c≦0.7, 0≦d≦0.1, 0.07≦z1≦0.15, 0.01≦z2≦0.1, and 1.9≦(x+z1)≦2.1 are satisfied.
1. An active material having a layered structure and represented by the following composition formula (1):
Li y Ni a Co b Mn c M d O x F z1 P z2 (1)
wherein:
M is at least one element selected from the group consisting of Al, Si, Zr, Ti, Fe, Mg, Nb, Ba and V, and
1.9≦(a+b+c+d+y)≦2.1,
1.0≦y≦1.3,
0<a≦0.3,
0≦b≦0.25,
0.3≦c≦0.7,
0≦d≦0.1,
0.07≦z1≦0.15,
0.01≦z2≦0.1, and
1.9≦(x+z1)≦2.1 are satisfied.
2. A lithium ion secondary battery comprising:
a positive electrode having a positive electrode current collector and a positive electrode active material layer containing a positive electrode active material;
a negative electrode having a negative electrode current collector and a negative electrode active material layer containing a negative electrode active material;
a separator disposed between the positive electrode active material layer and the negative electrode active material layer; and
an electrolyte in contact with the negative electrode, the positive electrode, and the separator,
wherein the positive electrode active material includes the active material according to claim 1 .
3. The lithium ion secondary battery according to claim 2 , wherein the electrolyte is a nonaqueous electrolyte in which LiPF 6 is dissolved.
4. A method for manufacturing the active material according to claim 1 , the method comprising forming the active material from a lithium compound by
disposing the lithium compound on a surface of a positive electrode of a lithium ion secondary battery including a nonaqueous electrolyte in which LiPF 6 is dissolved; and
charging/discharging the lithium ion secondary battery once or multiple times, wherein:
the lithium compound has a layered structure and is represented by the following composition formula (2):
Li y Ni a Co b Mn c M d O x (2)
M is at least one element selected from the group consisting of Al, Si, Zr, Ti, Fe, Mg, Nb, Ba and V, and
1.9≦(a+b+c+d+y)≦2.1,
1.0≦y≦1.3,
0<a≦0.3,
0≦b≦0.25,
0.3≦c≦0.7,
0≦d≦0.1, and
1.90≦x≦2.05 are satisfied.
5. The method according to claim 4 , wherein a temperature of the lithium ion secondary battery at a time of charging/discharging is maintained at 0 to 40° C.