Active material, electrode, battery, and method of manufacturing active material
View Patent ↗An active material comprises a core particle containing LiCo (1-x) M x O 2 and/or Li(Mn (1-y) M y ) 2 O 4 , and a coating part covering at least part of a surface of the core particle, while the coating part contains LiVOPO 4 . Here, M is at least one element selected from the group consisting of Al, Mg, and transition elements, 0.95≧x≧0, 0.2≧y≧0, and V in LiVOPO 4 may partly be substituted by at least one element selected from the group consisting of Ti, Ni, Co, Mn, Fe, Zr, Cu, Zn, and Yb.
1. A positive active material comprising:
a core particle containing LiCo (1-x) M x O 2 ; and
a coating part covering at least part of a surface of the core particle,
wherein:
the coating part contains LiV (1-a) M a OPO 4 ,
M in the LiCo (1-x) M x O 2 is at least one element selected from the group consisting of Al, Mg, Ti, Cr, Mn, Fe, Co, Ni, Cu, and Zn,
0≦x≦0.95,
M in the LiV (1-a) M a OPO 4 may be at least one element selected from the group consisting of Ti, Ni, Co, Mn, Fe, Zr, Cu, Zn, and Yb, and
0≦a≦0.05.
2. The positive active material according to claim 1 , wherein the coating part has a thickness of 50 nm to 1 μm.
3. A positive electrode comprising a current collector and an active material containing layer provided on the current collector, the active material containing layer comprising the positive active material of claim 1 .
4. A lithium ion secondary battery comprising the positive electrode of claim 3 .
5. A method of manufacturing a positive active material, the method comprising a step of causing at least part of a surface of a core particle containing LiCo (1-x) M x O 2 to support LiV (1-a) M a OPO 4 ,
wherein:
M in the LiCo (1-x) M x O 2 is at least one element selected from the group consisting of Al, Mg, Ti, Cr, Mn, Fe, Co, Ni, Cu, and Zn,
0≦x≦0.95,
M in the LiV (1-a) M a OPO 4 may be at least one element selected from the group consisting of Ti, Ni, Co, Mn, Fe, Zr, Cu, Zn, and Yb, and
0≦a≦0.05.
6. The method of manufacturing a positive active material according to claim 5 , wherein the core particle and an LiV (1-a) M a OPO 4 particle are mixed in a fluidized bed.
7. The method of manufacturing a positive active material according to claim 5 , further comprising mixing a solution containing a precursor of LiV (1-a) M a OPO 4 and the core particle and then synthesizing LiVOPO 4 in the solution.