Cathode active material for lithium secondary battery, and lithium secondary battery including same
It is related to a positive electrode active material for lithium secondary battery, and to a lithium secondary battery containing the same. To improve the battery characteristics of high-capacity positive electrode materials by simultaneously doping tungsten (W) element, which has an excellent effect on electrical conductivity, and boron (B) element, which is positioned on the surface to suppress the negative reaction of residual lithium and electrolyte solution.
1 . A positive electrode active material for lithium secondary battery, wherein:
the positive electrode active material for the lithium secondary battery is in the form of a secondary particle composed of primary particles,
the primary particle is a structure with a rough surface,
the positive electrode active material for the lithium secondary battery is lithium metal oxide and has a structure doped with tungsten (W) and boron (B),
based on 1 mol % of a metal in the lithium metal oxide, tungsten (W) is doped with 0.0005 to 0.005 mol %, and boron (B) is doped with 0.0005 to 0.005 mol %,
doping amounts (mol %) of tungsten (W) and boron (B) are equal,
a specific area of the secondary particle is 0.19 m 2 /g or less, and
a grain size of the primary particle is 100 to 500 nm.
2 . The positive electrode active material of claim 1 , wherein:
the primary particle includes both a primary particle with a layered structure and a primary particle with a Rocksalt structure.
3 . The positive electrode active material of claim 1 , wherein:
the positive electrode active material for the lithium secondary battery is represented by Chemical Formula 1 below: [Chemical Formula 1]
Li a [(Ni x Co y Mn z ) 1-b-c A b A′ c ]O 2
in the Chemical Formula 1,
it is that 0.8≤a≤1.3, 0.001≤b≤0.015, 0≤c≤0.1, 0.50≤x≤0.95, and 0≤y≤0.3, 0<z≤0.5,
A is W and B,
A′ is at least one selected from Zr, Ti, Al, and Mg.
4 . The positive electrode active material of claim 1 , wherein:
the positive electrode active material for the lithium secondary battery is lithium metal oxide and has a structure doped with tungsten (W) and boron (B),
the boron (B) is doped to the surface in the form of B 2 O 3 ,
the tungsten (W) is doped to the surface in the form of WO 3 , and is doped to the inside in the form of WO 2 .
5 . A lithium secondary battery comprises:
a positive electrode;
a negative electrode; and
an electrolyte;
the positive electrode comprises the positive electrode active material for the lithium secondary battery according to claim 1 .
6 . A positive electrode active material for lithium secondary battery, wherein,
the positive electrode active material for the lithium secondary battery is a lithium metal oxide, and has a structure doped with tungsten (W) and boron (B), based on 1 mol % of a metal in the lithium metal oxide, tungsten (W) is doped with 0.0005 to 0.005 mol %, and boron (B) is doped with 0.0005 to 0.005 mol %,
doping amounts (mol %) of tungsten (W) and boron (B) are equal,
a specific area of a secondary particle is 0.19 m 2 /g or less, and
a grain size of a primary particle is 100 to 500 nm.