Positive electrode slurry composition, and positive electrode sheet prepared thereof, secondary battery, battery module, battery pack and power consumption apparatus
A positive electrode slurry composition, and a positive electrode sheet prepared thereof, a secondary battery, a battery module, a battery pack and a power consumption apparatus are described. The positive electrode slurry composition includes a positive electrode active material, a pre-lithiation material, and a binder, where the binder is shown in Formula (II) where R 1 , R 2 , x, y, and z have meanings defined in the specification, a volume average particle size is D10≥0.3 μm, a volume average particle size D50 is 0.5-10 μm. The positive electrode slurry composition includes the binder in Formula (II) and the positive electrode active material with a specific particle size range, which is not easy to agglomerate and has high stability, and is conducive to improving machinability of the positive electrode sheet, and the binder in Formula (II) is conducive to improving bonding strength between the positive electrode active material and the pre-lithiation material.
1. A positive electrode slurry composition, comprising a positive electrode active material, a pre-lithiation material and a binder;
the positive electrode active material being selected from one or more of the group consisting of: Li q Fe p PO 4 , Li q Co p PO 4 , Li q Mn p PO 4 , Li q Co p O 2 , Li q Ni p O 2 , Li q Mn p O 2 , Li q Mn p O 4 , Li q Ni a1 Co b Mn c M1 d O 2 , Li q Ni 1-u Co u O 2 , Li q Co 1-u Mn u O 2 , Li q Ni 1-u Mn u O 2 , Li q Ni α Co β Mn γ O 4 , Li q Mn 2-η Ni η O 4 , and Li q Mn 2-η Co η O 4 , wherein M1 is selected from one or more of the group consisting of Al, Mo, Nd, and Zn, p and q independently satisfy 0.5≤q≤1.1, 0.95≤p≤1.25, 0<a1<1, 0<b<1, 0<<<1, 0≤d<1, and a1+b+c+d=1, u independently satisfies 0<<1, 0<α<2, 0<β<2, 0<γ<2, and α+β+γ=2, η independently satisfies 0<η<2,
and wherein a volume average particle size of the positive electrode active material is D10≥0.3 μm, a volume average particle size D50 is 0.5-10 μm;
the pre-lithiation material being selected from one or more of the group consisting of: Li a2 M2O 0.5(2+a2) , Li 2 M2O 3 , Li 2 M4O 4 , Li 3 M5O 4 , Li 5 M6O 4 , Li 5 M7O 6 , Li 2 O, Li 2 O 2 , Li 2 C 2 O 4 , Li 2 C 3 O 5 , Li 2 C4O 4 , and Li 2 C 4 O 6 , wherein a2≥1.2, M2 is selected from one or more of the group consisting of Ni, Co, Fe, Mn, Zn, Mg, Ca, Cu, and Sn, M3 is selected from one or more of the group consisting of Ni, Co, Fe, Mn, Sn, and Cr, M4 is selected from one or more of the group consisting of Ni, Co, Fe, Mn, Sn, Cr, V, and Nb, M5 is selected from one or more of the group consisting of Ni, Co, Fe, Mn, Sn, Cr, V, Mo, and Nb, M6 is selected from one or more of the group consisting of Ni, Co, Fe, Mn, Sn, Cr, and Mo, M7 is selected from one or more of the group consisting of Ni, Co, and Mn, and a valence state of each element in M2, M3, M4, M5, M6, and M7 is respectively lower than a highest oxidation valence state thereof; wherein a mass fraction of the pre-lithiation material in the positive electrode slurry composition is 0.1 wt %-10 wt % and
the binder being shown in Formula (II):
wherein R1 and R2 are H or F independently of each other, x, y and z are all positive integers, and 0.52≤(4x+3y+2z)/(4x+4y+4z)≤0.7.
2. The positive electrode slurry composition according to claim 1 , wherein
the positive electrode active material is selected from one or more selected from the group consisting of Li q Fe p PO 4 , Li q Mn 2p O 4 and Li q Ni α Co β Mn γ O 4 , wherein p and q independently satisfy 0.5≤q≤1.1, 0.95≤p≤1.25, 0<α<2, 0<β<2, 0<γ<2, and α+β+γ=2.
3. The positive electrode slurry composition according to claim 1 , wherein
the positive electrode active material is Li q Fe p PO 4 , wherein 0.5≤q≤1.1, and 0.95≤p≤1.25.
4. The positive electrode slurry composition according to claim 3 , wherein
the positive electrode active material is Li q Fe p-k Me k PO 4 , wherein Me is selected from one or more of the group consisting of Sc, V, Cr, Mn, Ti, Al, Co, Ni, Cu, and Zn, and k<p, and 0<k≤0.5.
5. The positive electrode slurry composition according to claim 1 , wherein
lithium impurity content in the positive electrode active material is ≤3 weight %, based on a total weight of the positive electrode active material.
6. The positive electrode slurry composition according to claim 1 , wherein the pre-lithiation material at least comprises lithium metal oxide shown in Formula (III),
Li a3 Ni b2 Cu 1-b2-c2 M7 c2 O 2 Formula (III)
wherein 1<a3<3, 0<b2<1, 0≤c2<0.1, and M7 is selected from one or more of the group consisting of Zn, Sn, Mg, Fe, and Mn.
7. The positive electrode slurry composition according to claim 1 , wherein a weight-average molecular weight of the binder in Formula (II) is 500 thousand to 1.2 million.
8. The positive electrode slurry composition according to claim 1 , wherein
a mass fraction of the binder in Formula (II) in the positive electrode slurry composition is 0.2 wt %-10 wt.
9. The positive electrode slurry composition according to claim 1 , wherein
a mass fraction of the pre-lithiation material in the positive electrode slurry composition is 0.1 wt %-10 wt %.
10. The positive electrode slurry composition according to claim 1 , wherein
a mass ratio of the pre-lithiation material to the binder in Formula (II) in the positive electrode slurry composition is 0.2-2.
11. The positive electrode slurry composition according to claim 1 , wherein
volume average particle size D50 of the pre-lithiation material is 5 μm-15 μm.
12. The positive electrode slurry composition according to claim 1 , wherein
the binder is selected from one or more of the group consisting of: carboxymethyl cellulose, hydroxypropyl cellulose, polyacrylic acid, polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl alcohol, starch, polyvinylpyrrolidone, polyethylene, polypropylene, ethylene propylene propadiene terpolymer or sulfonated ethylene propylene propadiene terpolymer, ethylene propylene butadiene terpolymer or sulfonated ethylene propylene butadiene terpolymer, ethylene propylene pentadiene terpolymer or sulfonated ethylene propylene pentadiene terpolymer, ethylene propylene hexadiene terpolymer or sulfonated ethylene propylene hexadiene terpolymer,
styrene butadiene rubber, and fluorine rubber; and/or
the positive electrode slurry composition further comprises a dispersant selected from one or more of the group consisting of: sodium polyacrylate, sodium dodecyl benzene sulfonate, polypentene nitrile, polyacrylonitrile, and phenol polyoxyethylene ether.
13. A positive electrode sheet comprising a positive electrode slurry composition according to claim 1 .
14. The positive electrode sheet according to claim 13 , wherein
a mass fraction of the positive electrode slurry composition in a film layer of the positive electrode sheet is not less than 80%.
15. A secondary battery comprising the positive electrode sheet according to claim 13 .
16. A battery module comprising the secondary battery according to claim 15 .
17. A battery back comprising the battery module according to claim 16 .
18. A battery pack comprising more than one of the secondary battery according to claim 15 .
19. A power consumption apparatus comprising
more than one of the secondary battery according to claim 15 .