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US-20260128301-A1 - POSITIVE ELECTRODE MATERIAL FOR SODIUM-ION BATTERY, AND PREPARATION METHOD THEREOF AND USE THEREOF

US20260128301A1US 20260128301 A1US20260128301 A1US 20260128301A1US-20260128301-A1

Abstract

The present application provides a positive electrode material for a sodium-ion battery, and a preparation method thereof and use thereof, where the positive electrode material for the sodium-ion battery has a chemical general formula Na a Ni b Fe c Mn d M e A f O 2 , where the element M and the element A are doping elements, M-O of the element M has a bond energy of greater than 500 kJ/mol, the element A has an ionic radius of greater than or equal to 0.06 nm, and the element A has a valence state of +3 of higher, and a XRD pattern of the positive electrode material for the sodium-ion battery is free of impurity phase diffraction peak in a range of 42.5°-43.5°. The element M is doped at a position of an interstitial atom, and the element A can preferentially replace a transition metal at a transition metal site.

Inventors

  • Guozheng SUN
  • Wenfei ZHANG
  • Jiankang Xu
  • Zunzhi WANG
  • Jian Yu
  • Rui Liu

Assignees

  • NINGBO RONBAY NEW ENERGY TECHNOLOGY Co.,Ltd.

Dates

Publication Date
20260507
Application Date
20251229
Priority Date
20231025

Claims (20)

  1. 1 . A positive electrode material for a sodium-ion battery, wherein the positive electrode material for the sodium-ion battery has a chemical general formula Na a Ni b Fe c Mn d M e A f O 2 , wherein 0.85≤a≤1.1, 0.1≤b≤0.5, 0.1≤c≤0.4, 0.1≤d≤0.4, 0.001≤e≤0.02, 0.001≤f≤0.02; the element M and the element A are doping elements, M-O of the element M has a bond energy of greater than 500 kJ/mol, the element A has an ionic radius of greater than or equal to 0.06 nm, and the element A has a valence state of +3 of higher; a XRD pattern of the positive electrode material for the sodium-ion battery is free of impurity phase diffraction peak in a range of 42.5°-43.5°.
  2. 2 . The positive electrode material for the sodium-ion battery according to claim 1 , wherein the bond energy of M-O of the element M is greater than 700 kJ/mol.
  3. 3 . The positive electrode material for the sodium-ion battery according to claim 1 , wherein the ionic radius of the element A is 0.06 nm-0.11 nm.
  4. 4 . The positive electrode material for the sodium-ion battery according to claim 1 , wherein the XRD pattern of the positive electrode material for the sodium-ion battery has no NiO and/or ZnO diffraction peaks in a range of 42.5°-43.5°.
  5. 5 . The positive electrode material for the sodium-ion battery according to claim 1 , wherein the element M comprises at least one of Al, Nb, Mg, Si, W and Ti.
  6. 6 . The positive electrode material for the sodium-ion battery according to claim 5 , wherein the element M comprises at least two of Al, Nb, Mg, Si, W and Ti.
  7. 7 . The positive electrode material for the sodium-ion battery according to claim 1 , wherein the element A comprises at least one of Y, Zr, Nb, Sb, Te, La, Ce and Ta.
  8. 8 . The positive electrode material for the sodium-ion battery according to claim 1 , wherein a Na—O interlayer spacing in the positive electrode material for the sodium-ion battery is 3.30 Å-3.50 Å.
  9. 9 . The positive electrode material for the sodium-ion battery according to claim 1 , wherein the positive electrode material for the sodium-ion battery further comprises a coating layer covering at least part of a surface of the material having the chemical general formula Na a Ni b Fe c Mn d M e A f O 2 ; and the coating layer comprises at least one of Al 2 O 3 , WO 3 , SrO, CeO 2 and TiO 2 .
  10. 10 . The positive electrode material for the sodium-ion battery according to claim 2 , wherein the positive electrode material for the sodium-ion battery further comprises a coating layer covering at least part of a surface of the material having the chemical general formula Na a Ni b Fe c Mn d M e A f O 2 ; and the coating layer comprises at least one of Al 2 O 3 , WO 3 , SrO, CeO 2 and TiO 2 .
  11. 11 . The positive electrode material for the sodium-ion battery according to claim 9 , wherein the coating layer has a thickness of less than or equal to 50 nm.
  12. 12 . The positive electrode material for the sodium-ion battery according to claim 1 , wherein a ratio of D10 particle diameter of the positive electrode material for the sodium-ion battery after roll pressing by a 3T pressure roller to D10 particle diameter of the positive electrode material for the sodium-ion battery before roll pressing is greater than or equal to 0.73.
  13. 13 . A preparation method of the positive electrode material for the sodium-ion battery according to claim 1 , comprising the following steps: mixing a nickel-iron-manganese precursor, a sodium source, a first additive containing an element M and a second additive containing an element A, and then sintering, to obtain the positive electrode material for the sodium-ion battery; wherein the sintering specifically comprises: a first heat preservation sintering at 600° C.-750° C., a second heat preservation sintering at 850° C.-920° C., and a third heat preservation sintering at 930° C.-980° C.
  14. 14 . The preparation method of the positive electrode material for the sodium-ion battery according to claim 13 , wherein a temperature of the first heat preservation sintering is 600° C.-700° C., and a temperature of the second heat preservation sintering is 850° C.-900° C.
  15. 15 . The preparation method of the positive electrode material for the sodium-ion battery according to claim 13 , wherein a time of the first heat preservation sintering is 1 h-3 h; and/or a time of the second heat preservation sintering is 1 h-3 h; and/or a time of the third heat preservation sintering is 12 h-16 h.
  16. 16 . The preparation method of the positive electrode material for the sodium-ion battery according to claim 13 , wherein after the third heat preservation sintering, the preparation method further comprises: crushing the sintered material, adding a coating layer material thereto, and performing a fourth heat preservation sintering.
  17. 17 . The preparation method of the positive electrode material for the sodium-ion battery according to claim 16 , wherein a temperature of the fourth heat preservation sintering is 400° C.-450° C.; and/or a time of the fourth heat preservation sintering is 12 h-16 h.
  18. 18 . A positive electrode sheet for a sodium-ion battery, comprising the positive electrode material for the sodium-ion battery according to claim 1 .
  19. 19 . A sodium-ion battery, comprising the positive electrode sheet for the sodium-ion battery according to claim 18 .
  20. 20 . An electrical device, comprising the sodium-ion battery according to claim 19 .

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a continuation of International Application No. PCT/CN2024/123056, filed on Sep. 30, 2024, which claims priority to Chinese patent application No. 202311390637.1 filed with China National Intellectual Property Administration on Oct. 25, 2023 and entitled “Positive Electrode Material for Sodium Ion Battery, and Preparation Method Thereof and Use Thereof”. Both of the aforementioned applications are hereby incorporated by reference in their entireties. TECHNICAL FIELD The present application relates to the technical field of positive electrode materials for sodium-ion batteries, and in particular to positive electrode material for a sodium-ion battery and a preparation method thereof and use thereof. BACKGROUND In recent years, the new energy industry has developed rapidly, and sodium-ion batteries have attracted much attention due to their low cost, simple preparation methods, and excellent performance. Among them nickel-iron-manganese polycrystalline materials have been increasingly studied due to their good processability, high capacity and good cycle and the like. However, the nickel-iron-manganese polycrystalline materials produce excessive gas during cycling, which affects their large-scale application. In the sodium-ion batteries, a layered oxide positive electrode material has a main reaction of intercalation and deintercalation of sodium ions. When sodium ions are intercalated into the layered oxide positive electrode material from the electrolyte, the structure of the positive electrode material changes, and the layered oxide layers expand outward to form gaps. This process can lead to volume expansion of and stress accumulation in the positive electrode material, thereby affecting the cycle life and safety performance of the batteries. When sodium ions are deintercalated from the layered oxide positive electrode material, the structure of the positive electrode material returns to its original state, and the layered oxide layers are stacked together again. However, due to volume change of the positive electrode material, not only the internal pressure of the batteries is increased, which causes gas generation from the positive electrode material, but also the interface between the positive electrode material and the electrolyte may fracture, which causes gas generation from the electrolyte. The gas generation has a certain impact on the performance and safety of the sodium-ion battery. Firstly, the gas generation increases the pressure inside the battery, which may lead to swelling, deformation, or even explosion of the battery. Secondly, the gas generation occupies the available space inside the battery, reducing the energy density of the battery. Moreover, the gas generation further leads to a decrease in battery's life, as the gas hinders the intercalation and deintercalation processes of sodium ions. Presently, the methods to address this problem include changing the structure of the layered electrode or changing the composition of the electrolyte. The former can better accommodate the volume change during the intercalation and deintercalation processes of sodium ions. The latter involves selecting an electrolyte with high solubility and low gas generation rate to minimize gas generation phenomena. In addition, the problem of the gas generation during cycling can be improved by using a water-washing method or reducing the operating voltage. However, the water-washing process will complicate the preparation process and increase the manufacturing cost; and reducing the operating voltage will reduce the capacity and affect the energy density of the cell. In view of this, the present application is hereby provided. SUMMARY A first object of the present application is to provide a positive electrode material for a sodium-ion battery, where the gas generation problem of the positive electrode material during cycling is improved by doping two doping elements with different properties. A M-O bond of an element M has a bond energy of greater than 500 kJ/mol, and an element A has an ionic radius of greater than or equal to 0.06 nm and a valence state of +3 or higher. The function of the element M is to be doped at a position of an interstitial atom, to confine oxygen and restrict oxygen release in a desodiation state. The doping of the element A may preferentially replace a transition metal at a transition metal site, playing a supporting role in the internal structure of the layered material and thus improving the gas generation problem of the sodium-ion positive electrode material during cycling. A second object of the present application is to provide a preparation method for the above positive electrode material for the sodium-ion battery. The method includes mixing a first additive containing an element M and a second additive containing an element A with a nickel-iron-manganese precursor material and a sodium source, and then sinter