Positive electrode active material for lithium secondary battery, positive electrode for lithium secondary battery, and lithium secondary battery
View Patent ↗A positive electrode active material for a lithium secondary battery includes secondary particles which are aggregates of primary particles that are capable of being doped and dedoped with lithium ions, in which the secondary particles have a total specific surface area of pores having a pore radius of 10 nm or more and 50 nm or less of 0.27 m 2 /g or more and 0.90 m 2 /g or less in a pore distribution measured by a mercury porosimetry method.
1. A positive electrode active material for a lithium secondary battery comprising:
secondary particles which are aggregates of primary particles that are capable of being doped and dedoped with lithium ions, wherein
the secondary particles have a total specific surface area of pores having a pore radius of 10 nm or more and 50 nm or less of 0.27 m 2 /g or more and 0.90 m 2 /g or less in the pore distribution measured by a mercury porosimetry method.
2. The positive electrode active material for a lithium secondary battery according to claim 1 , wherein
the secondary particles include a lithium-containing metal composite oxide whose compositional formula is represented by the following formula (I)
Li[Li x (Ni (1-y-z-w) Co y Mn z M w ) 1-x ]O 2 (I)
(in the formula (I), −0.1≤x≤0.2, 0<y≤0.4, 0≤z≤0.4, 0≤w≤0.1, M is one or more metals selected from the group consisting of Mg, Ca, Sr, Ba, Zn, B, Al, Ga, Ti, Zr, Ge, Fe, Cu, Cr, V, W, Mo, Sc, Y, Nb, La, Ta, Tc, Ru, Rh, Pd, Ag, Cd, In, and Sn.)
3. The positive electrode active material for a lithium secondary battery according to claim 2 , wherein
a content of lithium carbonate contained in a residual alkali salt on a surface of the secondary particles measured by neutralization titration is 0.3% by mass or less with respect to the total mass of the secondary particles, and a content of lithium hydroxide contained in the residual alkali salt on the surface of the secondary particles measured by neutralization titration is 0.3% by mass or less with respect to the total mass of the secondary particles.
4. The positive electrode active material for a lithium secondary battery according to claim 2 , wherein
a tap density is 2.3 g/cc or more.
5. The positive electrode active material for lithium secondary battery according to claim 2 , wherein
an average secondary particle diameter is 5 μm or more and 20 μm or less.
6. The positive electrode active material for a lithium secondary battery according to claim 2 , wherein, in the pore distribution measured by mercury porosimetry method, a pore specific volume of pores having a pore radius of 50 nm or more and 200 nm or less is 0.005 cm 3 /g or less.
7. The positive electrode active material for a lithium secondary battery according to claim 1 , wherein
a content of lithium carbonate contained in a residual alkali salt on a surface of the secondary particles measured by neutralization titration is 0.3% by mass or less with respect to the total mass of the secondary particles, and a content of lithium hydroxide contained in the residual alkali salt on the surface of the secondary particles measured by neutralization titration is 0.3% by mass or less with respect to the total mass of the secondary particles.
8. The positive electrode active material for a lithium secondary battery according to claim 7 , wherein
a tap density is 2.3 g/cc or more.
9. The positive electrode active material for lithium secondary battery according to claim 7 , wherein
an average secondary particle diameter is 5 μm or more and 20 μm or less.
10. The positive electrode active material for a lithium secondary battery according to claim 7 , wherein, in the pore distribution measured by mercury porosimetry method, a pore specific volume of pores having a pore radius of 50 nm or more and 200 nm or less is 0.005 cm 3 /g or less.
11. The positive electrode active material for a lithium secondary battery according to claim 1 , wherein
a tap density is 2.3 g/cc or more.
12. The positive electrode active material for lithium secondary battery according to claim 11 , wherein
an average secondary particle diameter is 5 μm or more and 20 μm or less.
13. The positive electrode active material for a lithium secondary battery according to claim 11 , wherein, in the pore distribution measured by mercury porosimetry method, a pore specific volume of pores having a pore radius of 50 nm or more and 200 nm or less is 0.005 cm 3 /g or less.
14. The positive electrode active material for lithium secondary battery according to claim 1 , wherein
an average secondary particle diameter is 5 μm or more and 20 μm or less.
15. The positive electrode active material for a lithium secondary battery according to claim 14 , wherein, in the pore distribution measured by mercury porosimetry method, a pore specific volume of pores having a pore radius of 50 nm or more and 200 nm or less is 0.005 cm 3 /g or less.
16. The positive electrode active material for a lithium secondary battery according to claim 1 , wherein, in the pore distribution measured by mercury porosimetry method, a pore specific volume of pores having a pore radius of 50 nm or more and 200 nm or less is 0.005 cm 3 /g or less.
17. A positive electrode for a lithium secondary battery including the positive electrode active material for a lithium secondary battery according to claim 1 .
18. A lithium secondary battery including the positive electrode for a lithium secondary battery according to claim 17 .
19. A positive electrode for a lithium secondary battery including the positive electrode active material for a lithium secondary battery according to claim 2 .
20. A lithium secondary battery including the positive electrode for a lithium secondary battery according to claim 19 .