Layered-oxide positive electrode active material and positive electrode plate, sodium-ion battery, and electric apparatus containing same
A layered-oxide positive electrode active material may have a molecular formula of Na x Mn a Fe b Ni c M d N e O 2-δ Q f , where a doping element M is selected from at least one of Cu, Li, Ti, Zr, K, Sb, Nb, Mg, Ca, Mo, Zn, Cr, W, Bi, Sn, Ge, or Al, a doping element N is selected from at least one of Si, P, B, S, or Se, a doping element Q is selected from at least one of F, Cl, or N, 0.66≤x≤1, 0<a≤0.70, 0<b≤0.70, 0<c≤0.23, 0≤d<0.30, 0≤e≤0.30, 0≤f≤0.30, 0≤δ≤0.30, a+b+c+d+e=1, 0<e+f≤0.30, 0<(e+f)/a≤0.30, 0.20≤d+e+f≤0.30, and (b+c)/a≤1.5.
1. A layered-oxide positive electrode active material, having a molecular formula of Na x Mn a Fe b Ni c M d N e O 2-δ Q f ,
wherein
a doping element M is selected from at least one of Cu, Li, Ti, Sb, or Mg; a doping element N is selected from at least one of Si, P, B or Se; a doping element Q is F, 0.66≤x≤1, 0<a≤0.70, 0<b≤0.70, 0<c≤0.23, 0≤d<0.30, 0<e≤0.30, 0<δ≤0.30, δ=f, a+b+c+d+e=1, 0<e+f≤0.30, 0<(e+f)/a≤0.30, 0.20≤d+e+f≤0.30 and 0<(b+c)/a≤1.5, and
a characteristic peak intensity I 1 in an X-ray diffraction pattern (003) of the layered-oxide positive electrode active material that has been soaked in water for 24 h and a characteristic peak intensity I 0 in an X-ray diffraction pattern (003) of the layered-oxide positive electrode active material without soaking satisfy I 1 /I 0 ≥0.2.
2. The layered-oxide positive electrode active material according to claim 1 , wherein a space group of the layered-oxide positive electrode active material measured by an X-ray diffraction technique is R 3 m.
3. The layered-oxide positive electrode active material according to claim 1 , wherein the layered-oxide positive electrode active material satisfies at least one of conditions (1) to (7):
(1) 0.80≤x≤1;
(2) 0.30≤a≤0.50;
(3) 0.20≤b≤0.40;
(4) 0.10≤c≤0.23;
(5) 0<e+f≤0.10;
(6) 0.05≤(e+f)/a≤0.30; or
(7) 0≤δ≤0.10.
4. The layered-oxide positive electrode active material according to claim 1 , wherein the layered-oxide positive electrode active material satisfies condition (10):
(10) 0<d<0.30, 0<e<0.30, and 0<δ<0.30.
5. The layered-oxide positive electrode active material according to claim 1 , wherein a layer spacing of 003 crystal plane d 003 of the layered-oxide positive electrode active material is 0.53 nm to 0.54 nm.
6. The layered-oxide positive electrode active material according to claim 1 , wherein a median particle size by volume D v 50 of the layered-oxide positive electrode active material is 10 μm to 30 μm.
7. The layered-oxide positive electrode active material according to claim 1 , wherein a specific surface area of the layered-oxide positive electrode active material is 0.1 m 2 /g to 5 m 2 /g.
8. The layered-oxide positive electrode active material according to claim 1 , wherein a tap density of the layered-oxide positive electrode active material is 1 g/cm 3 to 3 g/cm 3 .
9. The layered-oxide positive electrode active material according to claim 1 , wherein a powder compacted density of the layered-oxide positive electrode active material under a pressure of 8 tons is 3 g/cm 3 to 5 g/cm 3 .
10. A positive electrode plate, comprising the layered-oxide positive electrode active material according to claim 1 .
11. A sodium-ion battery, comprising the positive electrode plate according to claim 10 .
12. An electric apparatus, comprising at least one of the sodium-ion battery according to claim 11 , a battery module, and a battery pack, wherein the battery module and the battery pack are assembled with the sodium-ion battery, and the sodium-ion battery, battery module, or battery pack is used as a power source or energy storage unit for the electric apparatus.