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CN-120453281-B - Electrode plate, preparation method thereof, battery pack and electric equipment

CN120453281BCN 120453281 BCN120453281 BCN 120453281BCN-120453281-B

Abstract

The invention provides an electrode plate, a preparation method thereof, a battery pack and electric equipment, wherein the electrode plate comprises an electrode current collector and an electrode coating layer positioned on at least one side surface of the electrode current collector, the electrode coating layer comprises electrode active materials, the electrode coating layer comprises orientation areas and non-orientation areas which are arranged in a staggered manner in a first direction, the OI value of the orientation areas is smaller than the OI value of the non-orientation areas, and the first direction is intersected with the thickness direction of the electrode coating layer. The invention can reduce the impedance of the battery and improve the cycle stability of the battery.

Inventors

  • LIU YANG
  • HE KEFENG
  • YUAN XIAOTAO
  • LEI YU
  • LI JINYANG

Assignees

  • 比亚迪股份有限公司

Dates

Publication Date
20260505
Application Date
20240806

Claims (18)

  1. 1. An electrode sheet, characterized by comprising an electrode current collector, and an electrode coating layer located on at least one side surface of the electrode current collector, the electrode coating layer comprising an electrode active material; The electrode coating comprises an orientation zone and a non-orientation zone which are staggered in a first direction, wherein the OI value of the orientation zone is smaller than that of the non-orientation zone, the first direction is intersected with the thickness direction of the electrode coating, the orientation coefficient lambda of the electrode coating is more than or equal to 0.4 and less than or equal to 2.5, lambda=L 1 /L 2 ,L 1 is the width of the orientation zone, L 2 is the width of the non-orientation zone, the OI value of the orientation zone is 0.1-15, the OI value of the non-orientation zone is 20-40, the electrode sheet is a negative electrode sheet, and the electrode active material comprises graphite.
  2. 2. The electrode sheet of claim 1, wherein the ratio of the OI value of the oriented region to the OI value of the non-oriented region is 0.005-0.75.
  3. 3. The electrode sheet according to claim 1 or 2, wherein the OI value of the orientation zone is 0.2 to 5.
  4. 4. Electrode sheet according to claim 1 or 2, characterized in that, The width L 1 of the alignment region satisfies 0.05cm < L 1 <10cm; And/or the width L 2 of the non-oriented region satisfies 0< L 2 <80 cm.
  5. 5. The electrode sheet of claim 3, wherein the width L 1 of the orientation zone satisfies 0.05cm < L 1 <10cm; And/or the width L 2 of the non-oriented region satisfies 0< L 2 <80 cm.
  6. 6. The electrode sheet of claim 4, wherein the non-oriented region has a width L 2 that satisfies 0.02 cm < L 2 <25cm.
  7. 7. The electrode sheet of claim 5, wherein the non-oriented region has a width L 2 that satisfies 0.02 cm < L 2 <25cm.
  8. 8. The electrode sheet according to claim 1 or 2, wherein the first direction is a length direction of the electrode coating.
  9. 9. The electrode sheet of claim 3, wherein the first direction is a length direction of the electrode coating.
  10. 10. The electrode sheet according to claim 1 or 2, wherein the particle diameter Dv50 of the electrode active material is 7 μm to 16 μm.
  11. 11. The electrode sheet according to claim 3, wherein the particle diameter Dv50 of the electrode active material is 7 μm to 16 μm.
  12. 12. Electrode sheet according to claim 1 or 2, characterized in that, The surface density of the electrode coating is 165 g m -2 ~280 g m -2 ; And/or the electrode coating has a compacted density of 1.48 cm -3 ~1.6 g cm -3 ; and/or the thickness of the electrode coating is 103-197 mu m.
  13. 13. The electrode sheet of claim 3, wherein the electrode coating has an areal density of 165 g m -2 ~280 g m -2 ; And/or the electrode coating has a compacted density of 1.48 cm -3 ~1.6 g cm -3 ; and/or the thickness of the electrode coating is 103-197 mu m.
  14. 14. A method for producing an electrode sheet according to any one of claims 1 to 13, comprising the steps of: Coating the slurry containing the electrode active material on the surface of the electrode current collector, and forming a wet film on the surface of the electrode current collector to obtain a pole piece precursor; And the electrode plate is manufactured by enabling the electrode plate precursor to pass through a magnetic field, forming the orientation area and the non-orientation area in the process of passing through the magnetic field by the electrode plate precursor, wherein the magnetic field is provided by a magnetic assembly, the magnetic assembly comprises N-pole magnets and S-pole magnets which are staggered along a fourth direction, and the moving direction of the electrode plate precursor when passing through the magnetic field is intersected with the fourth direction or parallel to the fourth direction.
  15. 15. The method for producing an electrode sheet according to claim 14, wherein, In the process of enabling the pole piece precursor to pass through a magnetic field, the moving speed of the pole piece precursor is 1 m/min-5 m/min; and/or, in the process of enabling the pole piece precursor to pass through the magnetic field, the distance between the pole piece precursor and the magnetic assembly is 0.5 cm-5 cm; And/or, during the process of passing the pole piece precursor through the magnetic field, the magnetic components are respectively arranged on two opposite sides of the thickness direction of the pole piece precursor; and/or, in the magnetic component, the distance between the adjacent N pole magnet and the S pole magnet is 0-0.5 cm; and/or the width of the N pole magnet in the fourth direction is 1 cm-2 cm; and/or the width of the S-pole magnet in the fourth direction is 1 cm-2 cm.
  16. 16. A battery comprising an electrode sheet according to any one of claims 1 to 13 or an electrode sheet produced according to the method of producing an electrode sheet according to claim 14 or 15.
  17. 17. A battery comprising the battery of claim 16.
  18. 18. A powered device comprising the battery of claim 16 or the battery pack of claim 17.

Description

Electrode plate, preparation method thereof, battery pack and electric equipment Technical Field The invention relates to the field of batteries, in particular to an electrode plate, a preparation method thereof, a battery pack and electric equipment. Background The electrode plate is an important component of the battery, the diffusion capacity of active ions such as lithium ions in the electrode plate determines the charging rate of the battery (such as a power battery), the orientation degree of the active materials in the electrode plate is regulated and controlled to enable the active ions such as lithium ions to be directionally arranged in a state of being beneficial to being embedded into the active materials, the rapid transmission of the active ions such as lithium ions in the electrode plate can be promoted, the impedance of the electrode plate is reduced, the performance such as the rapid charging capacity of the battery is improved, however, the expansion of the active materials in the electrode plate in the charging and discharging processes of the battery is increased, phenomena such as falling and stripping easily occur in the long-cycle process of the battery are affected, and the cycle stability and the like of the battery are affected. Therefore, how to reduce the battery impedance and improve the cycle stability of the battery is a technical problem to be solved by those skilled in the art. Disclosure of Invention The invention provides an electrode plate, a preparation method thereof, a battery pack and electric equipment, which can reduce the impedance of the battery and improve the cycle stability of the battery, and effectively overcome the defects in the prior art. According to one aspect of the invention, an electrode sheet is provided, the electrode sheet comprises an electrode current collector and an electrode coating layer positioned on at least one side surface of the electrode current collector, the electrode coating layer comprises electrode active materials, the electrode coating layer comprises oriented areas and non-oriented areas which are staggered in a first direction, the OI value of the oriented areas is smaller than that of the non-oriented areas, and the first direction is intersected with the thickness direction of the electrode coating layer. According to one embodiment of the present invention, the ratio of the OI value of the oriented region to the OI value of the non-oriented region is 0.002 to 0.75. According to one embodiment of the present invention, the OI value of the alignment region is 0.1 to 15, preferably 0.2 to 5, and/or the OI value of the non-alignment region is 20 to 40. According to one embodiment of the invention, the orientation coefficient lambda of the electrode coating layer satisfies 0< lambda <8, preferably 0.4 +.lambda≤2.5, lambda=L 1/L2,L1 is the width of the orientation zone and L 2 is the width of the non-orientation zone. According to an embodiment of the invention, the width L 1 of the oriented regions satisfies 0.05cm < L 1 <10cm, and/or the width L 2 of the non-oriented regions satisfies 0< L 2 <80cm, preferably 0.02cm < L 2 <25cm. According to an embodiment of the invention, the first direction is a length direction of the electrode coating. According to an embodiment of the present invention, the particle diameter Dv50 of the electrode active material is 7 μm to 16 μm. According to one embodiment of the invention, the surface density of the electrode coating is 165g m -2～280g m-2, and/or the compacted density of the electrode coating is 1.48cm -3～1.6g cm-3, and/or the thickness of the electrode coating is 103-197 μm. According to an embodiment of the present invention, the electrode sheet is a negative electrode sheet, and the electrode active material includes graphite. According to an embodiment of the present invention, the electrode sheet is a positive electrode sheet, and the electrode active material includes a positive ternary material and/or lithium iron phosphate. The preparation method of the electrode slice comprises the steps of coating slurry containing electrode active materials on the surface of an electrode current collector, forming a wet film on the surface of the electrode current collector to obtain a pole slice precursor, enabling the pole slice precursor to pass through a magnetic field, and forming the orientation area and the non-orientation area in the process of passing the pole slice precursor through the magnetic field to obtain the electrode slice, wherein the magnetic field is provided by a magnetic assembly, the magnetic assembly comprises N pole magnets and S pole magnets which are staggered along a fourth direction, and the moving direction of the pole slice precursor when passing through the magnetic field is intersected with or parallel to the fourth direction. According to one embodiment of the invention, the moving speed of the pole piece precursor in the process of passing the pole piece prec