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CN-121983677-A - Battery and battery device

CN121983677ACN 121983677 ACN121983677 ACN 121983677ACN-121983677-A

Abstract

The invention relates to the technical field of new energy sources and discloses a battery and a battery device, wherein the battery comprises a shell component and a winding electric core, the winding electric core comprises a blocking layer, the blocking layer comprises a base film sub-layer and a glue sub-layer, the blocking layer is adhered to the surface of an active material layer corresponding to a bending part through the glue sub-layer, at least one end of a negative electrode plate exceeds a positive electrode plate, the size of the exceeding part along a first direction is m, the base film sub-layer is penetrated with a through hole along the thickness direction, the air permeability of the blocking layer is n, the thickness of a single winding electric core is q, and the m, n and q meet the relation of 0.0045 (q multiplied by m)/n is less than or equal to 1.65. The battery provided by the invention controls (q multiplied by m)/n in an adaptive range, and can realize the coordination of anode lithium intercalation uniformity, ion transmission efficiency and structural stability.

Inventors

  • ZHANG YONGJIE
  • LI GUOWEI
  • XU JIULING
  • ZHAO HAO
  • FAN XINYE

Assignees

  • 中创新航科技集团股份有限公司

Dates

Publication Date
20260505
Application Date
20260120

Claims (20)

  1. 1. A battery, comprising: The lithium ion battery comprises a shell assembly (1) and at least one winding battery cell (2) arranged in the shell assembly, wherein the winding battery cell (2) comprises a positive plate (201), a negative plate (202) and a separation film (203) arranged between the positive plate (201) and the negative plate (202), the positive plate (201) and/or the negative plate (202) comprises a foil (2001) and an active material layer (2002) coated on at least one side of the foil (2001), and the positive plate (201) and/or the negative plate (202) comprises a bending part (2003) in a bending state; the winding battery core (2) is wound to form a bending section (21) and a flat section (22), and a plurality of layers of bending parts (2003) jointly form the bending section (21); The winding cell (2) further comprises a blocking layer (204), wherein the blocking layer (204) comprises a base film sub-layer (2041) and a glue sub-layer (2042) attached to the base film sub-layer (2041), and the blocking layer (204) is adhered to the surface of the active material layer (2002) corresponding to the bending part (2003) through the glue sub-layer (2042); Defining the opening direction of the shell component (1) as a first direction, wherein at least one end of the negative electrode plate (202) exceeds the positive electrode plate (201), the dimension of the exceeding part along the first direction is m, the unit is mm, the base film sub-layer (2041) is penetrated with a through hole (2043) along the thickness direction, the air permeability of the blocking layer (204) is s/100ml, the thickness of a single winding electric core (2) is q, the unit is mm, and the m, n and q meet the relation of 0.0045-q multiplied by m/n-1.65.
  2. 2. The battery according to claim 1, characterized in that the thickness q of the individual wound cells (2) has a value in mm in the range 20≤q≤100.
  3. 3. The battery according to claim 1, characterized in that the total thickness of the multiple layers of positive electrode sheet (201) in the wound state is in the range of 20% -45% of the thickness of the single wound cell (2).
  4. 4. A battery according to claim 3, characterized in that the thickness of the active material layer (2002) of the positive electrode sheet (201) is in the range of 30 μm-210 μm; And/or the thickness of the foil (2001) of the positive electrode sheet (201) is in the range of 6 μm to 18 μm.
  5. 5. The battery according to claim 1, characterized in that the proportion of the total thickness of the plurality of layers of negative electrode sheets (202) in the wound state to the thickness of the individual wound cells (2) ranges from 21% to 46%.
  6. 6. The battery according to claim 5, wherein the thickness of the active material layer (2002) of the negative electrode sheet (202) is in the range of 30 μm to 200 μm; And/or the thickness of the foil (2001) of the negative electrode sheet (202) is in the range of 4 μm to 12 μm.
  7. 7. The battery according to claim 1, wherein the thickness of the separator (203) ranges from 10 μm to 70 μm.
  8. 8. The battery according to any one of claims 1 to 7, wherein m has a value in mm in a range of 0.4≤m≤2.5.
  9. 9. The battery according to any one of claims 1 to 7, wherein both ends of the active material layer (2002) of the negative electrode sheet (202) in the first direction exceed the active material layer (2002) of the positive electrode sheet (201), and the sum of the dimensions of the excess in the first direction is m2 in mm, satisfying 0.8≤m2≤4.2.
  10. 10. The battery according to any one of claims 1 to 7, characterized in that the winding cell (2) is provided with a positive tab (23) and a negative tab (24) respectively on the same side of the winding cell (2) as the tabs are provided, and that the active material layer (2002) of the negative tab (202) is provided beyond the active material layer (2002) of the positive tab (201); The positive electrode lugs (23) and the negative electrode lugs (24) are arranged at intervals along a second direction, wherein the second direction is perpendicular to the first direction, and the minimum distance between the positive electrode lugs (23) and the negative electrode lugs (24) along the second direction is e, and the unit is mm, so that the requirement that e is more than or equal to 20 and less than or equal to 200 is met.
  11. 11. The battery according to claim 10, characterized in that the active material layer (2002) of the negative electrode tab (202) is flush with the end of the active material layer (2002) of the positive electrode tab (201) on the opposite side of the wound cell (2) where the tab is located.
  12. 12. The battery according to any one of claims 1 to 7, wherein, in the first direction, an end portion of the active material layer (2002) of the positive electrode sheet (201) located beyond one side of the active material layer (2002) of the negative electrode sheet (202) is provided with a tab gum, which at least partially overlaps the active material layer (2002) of the positive electrode sheet (201), and at this time, the gas permeability n of the barrier layer (204) has a value range satisfying 150 n≤1800 in s/100ml.
  13. 13. The battery according to any one of claims 1 to 7, wherein a length of the separator (203) is longer than a length of the positive electrode sheet (201) in the first direction, and a difference between the length of the separator (203) and the length of the positive electrode sheet (201) is in a range of 0.6mm to 7.3mm.
  14. 14. The battery according to any one of claims 1 to 7, characterized in that, in the first direction, the separator (203) has a length equal to or greater than the length of the negative electrode sheet (202).
  15. 15. The battery according to claim 14, wherein the separator (203) has a length greater than the length of the negative electrode sheet (202) in the first direction, and the difference between the length of the separator (203) and the length of the negative electrode sheet (202) has a value ranging from 0.4mm to 4mm.
  16. 16. The battery according to any one of claims 1 to 7, characterized in that at least one end of the active material layer (2002) of the negative electrode sheet (202) is disposed beyond the active material layer (2002) of the positive electrode sheet (201) in the winding direction of the wound cell (2) by a distance of 20mm to 800mm.
  17. 17. The battery according to any one of claims 1 to 7, wherein the barrier layer (204) has a permeability n in a range of 150≤n≤2000.
  18. 18. The battery according to any one of claims 1 to 7, characterized in that the area of the individual through holes (2043) is in the range of 78.5 μm 2 -196250μm 2 .
  19. 19. The battery according to any one of claims 1 to 7, characterized in that the pitch between adjacent through holes (2043) has a value in the range of 500 μm to 2000 μm.
  20. 20. The cell of any of claims 1 to 7, wherein the thickness of the glue sub-layer (2042) is 10% -80% of the thickness of the barrier layer (204).

Description

Battery and battery device Technical Field The invention relates to the technical field of new energy, in particular to a battery and a battery device. Background In order to increase the energy density of the battery, the size of the battery tends to be increased to accommodate more active material. However, as the size of the battery increases, the risk of dropping active materials on the pole pieces increases, which not only affects the capacity stability of the battery, but also shortens the cycle life of the battery. According to analysis, the pole piece is more in material falling condition at the bending part of the winding core, and in the related art, in order to inhibit the material falling of the pole piece, the fixing effect on active substances is increased by attaching an adhesive tape at the bending part of the winding core, so that the material falling risk of the pole piece is reduced. However, as the battery is used for a long time, the adhesive tape attached to the bending part of the winding core can obstruct the transmission of lithium ions, so that the phenomenon of lithium precipitation easily occurs at the bending part, lithium dendrite accumulation occurs, and then the diaphragm is easily pierced to cause internal short circuit, so that potential safety hazards exist. Disclosure of Invention In view of this, the present invention provides a battery and a battery device, so as to solve the problem that the adhesive tape attached to the bending part of the winding core is easy to increase the risk of lithium precipitation and cause short circuit. In a first aspect, the present invention provides a battery comprising: The battery comprises a shell component and at least one winding battery cell arranged in the shell component, wherein the winding battery cell comprises a positive plate, a negative plate and a separation film arranged between the positive plate and the negative plate; The winding battery core is wound to form a bending section and a flat section, and the bending sections are formed by the multi-layer bending parts together; The winding cell also comprises a blocking layer, wherein the blocking layer comprises a base film sub-layer and a glue sub-layer attached to the base film sub-layer, and the blocking layer is adhered to the surface of the active material layer corresponding to the bending part through the glue sub-layer; Defining the opening direction of the shell assembly as a first direction, wherein at least one end of the negative plate exceeds the positive plate, the dimension of the exceeding part along the first direction is m, the unit is mm, the base film sub-layer is penetrated with a through hole along the thickness direction, the air permeability of the barrier layer is n, the unit is s/100ml, the thickness of a single winding electric core is q, the unit is mm, and the m, n and q meet the relation of 0.0045 (q multiplied by m)/n is less than or equal to 1.65. The lithium separation method has the beneficial effects that when m, n and q meet the relation, the risk of lithium separation of the bending section of the winding cell in the battery is small, the use safety performance of the battery is improved, the adhesive strength between the blocking layer of the bending section and the surface of the active material layer is high, the blocking layer is not easy to fall off, the protection effect is good, the risk of material dropping of the bending section can be reduced, and the service life of the battery is prolonged. When the formula value of (q multiplied by m)/n is too large, the distribution of through holes is too dense, the electric core is too thick or the redundancy of the negative electrode is too large, the risk of material dropping is large, the cycling stability of the battery is reduced, and when the formula value is too small, the lithium ion transmission is blocked, and the lithium precipitation risk is increased. Therefore, the (q multiplied by m)/n is controlled in the adaptive range, and the coordination of the lithium intercalation uniformity, the ion transmission efficiency and the structural stability of the negative electrode can be realized, so that the safety performance and the service life of the battery are improved. In a second aspect, the invention also provides a battery device, which comprises a battery device body and the battery electrically connected with the battery device body. Since the battery device includes the battery, it has the same effect as the battery, and is not described herein. Drawings In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effor