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CN-122000273-A - Preparation method of positive electrode plate of sodium ion battery, positive electrode plate and battery

CN122000273ACN 122000273 ACN122000273 ACN 122000273ACN-122000273-A

Abstract

The application discloses a preparation method of a positive electrode plate of a sodium ion battery, the positive electrode plate and the battery, and the method comprises the steps of coating first active slurry on two sides of a conductive substrate, and drying at a first preset temperature to obtain the first positive electrode plate, wherein the first active slurry comprises first sodium ion layered oxide; and (3) coating second active slurry on two sides of the first positive electrode plate, drying at a second preset temperature to obtain a second positive electrode plate, wherein the second active slurry comprises a second sodium ion layered oxide, the mass parts of sodium in the first sodium ion layered oxide and the mass parts of sodium in the second sodium ion layered oxide are different, and rolling the second positive electrode plate to obtain the positive electrode plate of the sodium ion battery. One of the first active slurry and the second active slurry can provide main capacity and ion rapid transmission, enhance rate capability, and the other can serve as a functional protection layer, improve interface stability and realize the functional coordination of capacity supply and interface protection.

Inventors

  • LEI YUN
  • ZHANG ZHIFENG
  • LUO QIAN
  • SHI HAIMIN

Assignees

  • 深圳市卡儿酷科技股份有限公司

Dates

Publication Date
20260508
Application Date
20251230

Claims (11)

  1. 1. The preparation method of the positive electrode plate of the sodium ion battery is characterized by comprising the following steps: Coating first active slurry on two sides of a conductive substrate, and drying at a first preset temperature to obtain a first positive electrode plate, wherein the first active slurry comprises a first sodium ion layered oxide; Coating second active slurry on two sides of the first positive electrode plate, and drying at a second preset temperature to obtain a second positive electrode plate, wherein the second active slurry comprises a second sodium ion layered oxide, and the mass parts of sodium in the first sodium ion layered oxide and the second sodium ion layered oxide are different; and rolling the second positive pole piece to obtain the positive pole piece of the sodium ion battery.
  2. 2. The method according to claim 1, wherein the first sodium ion layered oxide has a chemical formula of one of NaxMyO 2 and NazMyO 2 , and the second sodium ion layered oxide has a chemical formula of the other of NaxMyO 2 and NazMyO 2 , wherein M is at least one of manganese, nickel, iron, copper, cobalt, titanium, magnesium, or lithium, 0.5 +.x +.0.8, 0 +.y1, 0.9 +.z1.
  3. 3. The method for preparing a positive electrode sheet of a sodium ion battery according to claim 1 or 2, wherein the first sodium ion layered oxide comprises an O3 type sodium ion layered oxide, the second sodium ion layered oxide comprises a P2 type sodium ion layered oxide, or the first sodium ion layered oxide comprises a P2 type sodium ion layered oxide, and the second sodium ion layered oxide comprises an O3 type sodium ion layered oxide.
  4. 4. The method of producing a positive electrode sheet of a sodium ion battery according to claim 1, wherein an area density of the positive electrode sheet of the sodium ion battery ranges from [8 mg per square centimeter, 37.2 mg per square centimeter ], the area density being a ratio between a mass sum of the first sodium ion layered oxide and the second sodium ion layered oxide and a coated area of the first active paste or the second active paste coated on a conductive substrate.
  5. 5. The method according to claim 4, wherein in the case where the first sodium ion layered oxide includes a P2 type sodium ion layered oxide and the second sodium ion layered oxide includes an O3 type sodium ion layered oxide, the range of the coating thickness of the first active paste includes [55 micrometers, 65 micrometers ], the range of the coating thickness of the second active paste includes [40 micrometers, 50 micrometers ], The range of values for the solids content of the first active slurry includes [51%,56% ], the viscosity includes [4000 millipascal-seconds, 7000 millipascal-seconds ], the range of values for the solids content of the second active slurry includes [51%,56% ], and the viscosity includes [4000 millipascal-seconds, 7000 millipascal-seconds ].
  6. 6. The method for producing a positive electrode sheet of a sodium ion battery according to any one of claims 1 to 5, wherein the first active slurry further comprises a conductive agent and a binder, wherein the mass ratio of the first sodium ion layered oxide in the first active slurry ranges from [90%,95% ], the mass ratio of the conductive agent in the first active slurry ranges from [1.0%,4.0% ], and the mass ratio of the binder in the first active slurry ranges from [1%,3% ]; The second active slurry further comprises a conductive agent and a binder, wherein the mass ratio of the second sodium ion layered oxide in the second active slurry ranges from [90% to 95% ], the mass ratio of the conductive agent in the second active slurry ranges from [1.0% to 4.0% ], and the mass ratio of the binder in the second active slurry ranges from [1% to 3% ].
  7. 7. The method of manufacturing a positive electrode sheet of a sodium ion battery according to claim 6, wherein the conductive agent comprises at least one of superconductive carbon black, acetylene black, carbon nanotubes or multi-walled carbon nanotube graphene, and the binder comprises polyvinylidene fluoride.
  8. 8. The method for preparing a positive electrode sheet of a sodium ion battery according to claim 6 or 7, further comprising: Adding the first sodium ion layered oxide, the conductive agent and the binder into an N-methyl-2-pyrrolidone solvent, and uniformly mixing to obtain the first active slurry; and adding the second sodium ion layered oxide, the conductive agent and the binder into the N-methyl-2-pyrrolidone solvent, and uniformly mixing to obtain the second active slurry.
  9. 9. The method for preparing a positive electrode sheet of a sodium ion battery according to claim 1, wherein the range of values of the first preset temperature and the second preset temperature comprises [80 ℃ and 130 ℃, the conductive substrate comprises aluminum foil, and the thickness of the conductive substrate comprises 12 μm.
  10. 10. A positive electrode tab of a sodium ion battery, comprising: a conductive substrate; The first positive electrode plate is formed by coating first active slurry on two sides of the conductive substrate, wherein the first active slurry comprises first sodium ion layered oxide; The second positive electrode plate is formed by coating second active slurry on two sides of the first positive electrode plate, the second active slurry comprises second sodium ion layered oxides, and the mass parts of sodium in the first sodium ion layered oxides and the mass parts of sodium in the second sodium ion layered oxides are different.
  11. 11. A sodium ion battery comprising: the positive electrode sheet of claim 10, and A negative electrode plate; A diaphragm; and the negative electrode plate, the diaphragm and the positive electrode plate are all arranged in the electrolyte.

Description

Preparation method of positive electrode plate of sodium ion battery, positive electrode plate and battery Technical Field The application relates to the technical field of batteries, in particular to a preparation method of a positive electrode plate of a sodium ion battery, the positive electrode plate of the sodium ion battery and the sodium ion battery. Background The layered positive electrode material of the sodium ion battery has the advantages of simple preparation method, easy technical transformation, high energy density, high reversible specific capacity, high rate capability, reversible sodium ion stripping/embedding capability and the like, and is outstanding in a plurality of positive electrode materials. However, single sodium-electric layered cathode materials still have more problems. For example, O3 type Ni-Fe-Mn based layered oxides have a higher theoretical capacity. Disclosure of Invention The embodiment of the application provides a preparation method of a positive electrode plate of a sodium ion battery, the positive electrode plate of the sodium ion battery and the sodium ion battery, which can solve at least one technical problem. In a first aspect, a method for preparing a positive electrode plate of a sodium ion battery according to an embodiment of the present application includes: Coating first active slurry on two sides of a conductive substrate, and drying at a first preset temperature to obtain a first positive electrode plate, wherein the first active slurry comprises a first sodium ion layered oxide; Coating second active slurry on two sides of the first positive electrode plate, and drying at the second preset temperature to obtain a second positive electrode plate, wherein the second active slurry comprises a second sodium ion layered oxide, and the mass parts of sodium in the first sodium ion layered oxide and the sodium in the second sodium ion layered oxide are different; and rolling the second positive pole piece to obtain the positive pole piece of the sodium ion battery. In a second aspect, a positive electrode sheet according to an embodiment of the present application includes: a conductive substrate; The first positive electrode plate is formed by coating first active slurry on two sides of the conductive substrate, wherein the first active slurry comprises first sodium ion layered oxide; The second positive electrode plate is formed by coating second active slurry on two sides of the first positive electrode plate, the second active slurry comprises second sodium ion layered oxides, and the mass parts of sodium in the first sodium ion layered oxides and the mass parts of sodium in the second sodium ion layered oxides are different. In a third aspect, a sodium ion battery according to one embodiment of the present application includes: the positive electrode sheet according to any one of the above embodiments, and A negative electrode plate; A diaphragm; and the negative electrode plate, the diaphragm and the positive electrode plate are all arranged in the electrolyte. According to the preparation method of the positive electrode plate of the sodium ion battery, the positive electrode plate of the sodium ion battery and the sodium ion battery, the first active slurry is coated on two sides of the conductive substrate and dried at a first preset temperature to obtain the first positive electrode plate, the first active slurry comprises first sodium ion layered oxide, the second active slurry is coated on two sides of the first positive electrode plate and dried at a second preset temperature to obtain the second positive electrode plate, the second active slurry comprises second sodium ion layered oxide, the mass parts of sodium in the first sodium ion layered oxide and the second sodium ion layered oxide are different, and the second positive electrode plate is rolled to obtain the positive electrode plate of the sodium ion battery. The first active slurry comprising the first sodium ion layered oxide and the second active slurry comprising the second sodium ion layered oxide are sequentially coated on two sides of the conductive substrate, one of the first active slurry and the second active slurry can provide main capacity and ion rapid transmission, the rate capability is enhanced, the other one can serve as a functional protective layer, the interface stability is improved, and the function coordination of capacity supply and interface protection is realized. Additional aspects and advantages of embodiments of the application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of embodiments of the application. Drawings The foregoing and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which: fig. 1 is a sc