Search

EP-4738506-A1 - SECONDARY BATTERY, BATTERY ASSEMBLY, AND ELECTRONIC DEVICE

EP4738506A1EP 4738506 A1EP4738506 A1EP 4738506A1EP-4738506-A1

Abstract

A secondary battery (100), a battery assembly (1002), and an electronic device (1000) are provided. The secondary battery (100) includes an electrode assembly (120) including a negative electrode sheet (10), a positive electrode sheet (20), and a separator (122) disposed between the negative electrode sheet (10) and the positive electrode sheet (20). A negative electrode uncoating area (18b) of the negative electrode sheet (10) includes a negative electrode tab (18b2) and a negative electrode connecting area (18b1). The negative electrode tab (18b2) includes a negative electrode tab body (18b22) and a negative electrode tab transition portion (18b21) including a first negative electrode tab transition end point (E11). A range of a distance (H3) in a first direction (D1) between the first negative electrode tab transition end point (E11) and the first separator end (122u) of the separator (122) in the first direction (D1) is 0.5mm to 2mm.

Inventors

  • ZHANG, WENJING

Assignees

  • AESC Japan Ltd.

Dates

Publication Date
20260506
Application Date
20251015

Claims (10)

  1. A secondary battery (100), comprising: an electrode assembly (120), comprising a negative electrode sheet (10), a positive electrode sheet (20), and a separator (122) disposed between the negative electrode sheet (10) and the positive electrode sheet (20), wherein the negative electrode sheet (10) comprises a negative electrode current collector (18) and a negative electrode active material layer (16), the negative electrode current collector (18) comprises a negative electrode coating area (18a) covered by the negative electrode active material layer (16) and a negative electrode uncoating area (18b) not covered by the negative electrode active material layer (16), a first direction (D1) is from the negative electrode coating area (18a) to the negative electrode uncoating area (18b), and the separator (122) comprises a first separator end (122u) in the first direction (D1), along the first direction (D1), the negative electrode uncoating area (18b) comprising a negative electrode tab (18b2) and a negative electrode connecting area (18b1) connected between the negative electrode tab (18b2) and the negative electrode coating area (18a), the negative electrode tab (18b2) comprising a negative electrode tab body (18b22) and a negative electrode tab transition portion (18b21) connected between the negative electrode connecting area (18b1) and the negative electrode tab body (18b22), the negative electrode tab transition portion (18b21) comprising a first negative electrode tab transition end point (E11) connected to the negative electrode connecting area (18b1), and the first negative electrode tab transition end point (E11) being a position where a tangent of the negative electrode tab transition portion (18b21) intersects with an extension direction of the negative electrode connecting area (18b1), and wherein a range of a distance (H3) by which the first negative electrode tab transition end point (E11) exceeds the first separator end (122u) in the first direction (D1) is 0.5mm to 2mm.
  2. The secondary battery (100) according to claim 1, wherein the negative electrode active material layer (16) comprises a first negative electrode end (16u) in the first direction (D1), and a range of a distance (H6) by which the first negative electrode tab transition end point (E11) exceeds the first negative electrode end (16u) in the first direction (D1) is 1.5mm to 3mm.
  3. The secondary battery (100) according to claim 2, wherein the positive electrode sheet (20) comprises a positive electrode current collector (28) and a positive electrode active material layer (26), the positive electrode active material layer (26) comprises a first positive electrode end (26u) in the first direction (D1), and a distance (H2) by which the first negative electrode end (16u) exceeds the first positive electrode end (26u) in the first direction (D1) is 1.0mm to 1.5mm.
  4. The secondary battery (100) according to claim 1, wherein the positive electrode sheet (20) comprises a positive electrode current collector (28) and a positive electrode active material layer (26), the positive electrode current collector (28) comprises a positive electrode coating area (28a) covered by the positive electrode active material layer (26) and a positive electrode uncoating area (28b) not covered by the positive electrode active material layer (26), a second direction (D2) is from the positive electrode coating area (28a) to the positive electrode uncoating area (28b), and the second direction (D2) is opposite to the first direction (D1); along the second direction (D2), the positive electrode uncoating area (28b) comprises a positive electrode tab (28b2) and a positive electrode connecting area (28b1) connected between the positive electrode tab (28b2) and the positive electrode coating area (28a), the positive electrode tab (28b2) comprises a positive electrode tab body (28b22) and a positive electrode tab transition portion (28b21) connected between the positive electrode connecting area (28b1) and the positive electrode tab body (28b22), the positive electrode tab transition portion (28b21) comprises a first positive electrode tab transition end point (E21) connected to the positive electrode connecting area (28b1), the first positive electrode tab transition end point (E21) is a position where a tangent of the positive electrode tab transition portion (28b21) intersects with an extending direction of the positive electrode connecting area (28b1); and the electrode assembly (120) further comprises an insulating layer (40), the insulating layer (40) covers the positive electrode connecting area (28b1), and a width (H8) of the insulating layer (40) in the second direction (D2) is 0.5mm to 2.5mm.
  5. The secondary battery (100) according to claim 4, wherein the negative electrode active material layer (16) comprises a second negative electrode end (161) in the second direction (D2), the insulating layer (40) comprises a first insulating end (40u) in the first direction (D1), and a range of a distance (H1) by which the second negative electrode end (161) exceeds the first insulating end (40u) in the second direction (D2) is 0.5mm to 1mm.
  6. The secondary battery (100) according to claim 5, wherein the insulating layer (40) comprises a second insulating layer end (401) in the second direction (D2), and a range of a distance (H7) by which the second insulating layer end (401) exceeds the second negative electrode end (161) in the second direction (D2) is 0.5mm to 1mm.
  7. The secondary battery (100) according to claim 1, wherein the negative electrode active material layer (16) comprises a first negative electrode end (16u) in the first direction (D1), and a range of a distance (H4) by which the first separator end (122u) exceeds the first negative electrode end (16u) in the first direction (D1) is 0.5mm to 1.5mm.
  8. The secondary battery (100) according to claim 4, further comprising: a shell (200), configured to accommodate the electrode assembly (120), and comprising a peripheral side wall (109) and an end wall (111) connected to one end of the peripheral side wall (109), another end of the peripheral side wall (109) having an opening (205), a pressure-welding portion (113) protruding inward is formed at the peripheral side wall (109) adjacent to the opening (205), and the electrode assembly (120) is located between the end wall (111) and the pressure-welding portion (113), wherein the negative electrode tab (18b2) faces toward the opening (205) and is connected to the shell (200) through a negative electrode current collecting plate (201), a welding position of the negative electrode current collecting plate (201) and the peripheral side wall (109) is located on a side of the pressure-welding portion (113) facing toward the electrode assembly (120); and the secondary battery (100) is a cylindrical battery.
  9. A battery assembly (1002), comprising the secondary battery (100) according to any one of claims 1-8.
  10. An electronic device (1000), comprising the battery assembly (1002) according to claim 9.

Description

BACKGROUND Technical Field The disclosure relates to a secondary battery, a battery assembly, and an electronic device. Related Art In a field of new energy power batteries, a secondary battery has more and more widespread applications. For example, the secondary battery (such as a lithium-ion battery) may be applied to an electronic device such as a vehicle, energy storage, a mobile phone, a tablet, a wearable device, a power bank, an electronic cigarette, a digital product, an electric tool, a power device, an energy storage device. One type of the secondary battery is a cylindrical battery, which includes a shell and an electrode assembly. The electrode assembly includes a positive electrode sheet, a first separator, a negative electrode sheet, and a second separator, which are stacked in sequence, wound into an electrode assembly, and then packaged in the shell. However, existing secondary batteries need further improved in certain aspects. SUMMARY In view of the problems existing in the related art, a purpose of the disclosure is to provide a secondary battery, a battery assembly, and an electronic device, which may at least avoid damaging a separator during a manufacturing process. To achieve the aforementioned purpose, embodiments of the disclosure provide a secondary battery. The secondary battery includes an electrode assembly including a negative electrode sheet, a positive electrode sheet, and a separator set between the negative electrode sheet and the positive electrode sheet. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode current collector includes a negative electrode coating area covered by the negative electrode active material layer, and a negative electrode uncoating area not covered by the negative electrode active material layer. A first direction is from the negative electrode coating area to the negative electrode uncoating area. The separator includes a first separator end in the first direction. Along the first direction, the negative electrode uncoating area includes a negative electrode tab and a negative electrode connecting area connected between the negative electrode tab and the negative electrode coating area. The negative electrode tab includes a negative electrode tab body and a negative electrode tab transition portion connected between the negative electrode connecting area and the negative electrode tab body. The negative electrode tab transition portion includes a first negative electrode tab transition end point connected to the negative electrode connecting area. The first negative electrode tab transition end point is a position where a tangent of the negative electrode tab transition portion intersects with an extension direction of the negative electrode connecting area. A range of a distance by which the first negative electrode tab transition end point exceeds the first separator end in the first direction is 0.5mm to 2mm. In some embodiments, the negative electrode active material layer includes a first negative electrode end in the first direction. A range of a distance by which the first negative electrode tab transition end point exceeds the first negative electrode end in the first direction is 1.5mm to 3mm. In some embodiments, the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer includes a first positive electrode end in the first direction. A distance by which the first negative electrode end exceeds the first positive electrode end in the first direction is 1.0mm to 1.5mm. In some embodiments, the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode current collector includes a positive electrode coating area covered by the positive electrode active material layer and a positive electrode uncoating area not covered by the positive electrode active material layer. A second direction is from the positive electrode coating area to the positive electrode uncoating area. The second direction is opposite to the first direction. Along the second direction, the positive electrode uncoating area includes a positive electrode tab and a positive electrode connecting area connected between the positive electrode tab and the positive electrode coating area. The positive electrode tab includes a positive electrode tab body and a positive electrode tab transition portion connected between the positive electrode connecting area and the positive electrode tab body. The positive electrode tab transition portion includes a first positive electrode tab transition end point connected to the positive electrode connecting area. The first positive electrode tab transition end point is a position where a tangent of the positive electrode tab transition portion intersects with