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CN-224217499-U - Single battery

CN224217499UCN 224217499 UCN224217499 UCN 224217499UCN-224217499-U

Abstract

The application discloses a single battery, and belongs to the technical field of batteries. The single battery comprises an electrode assembly, wherein the electrode assembly comprises a first pole piece, a diaphragm and a second pole piece, the first pole piece, the diaphragm and the second pole piece are stacked and wound, the electrode assembly comprises a straight area and two corner areas connected with the straight area, the two corner areas are respectively located on two opposite sides of the straight area in the first direction, the electrode assembly comprises a first side and a second side which are oppositely arranged in the second direction, the electrode assembly further comprises a first main tab and a first auxiliary tab which are identical in polarity, the first main tab and the first auxiliary tab are connected to the first pole piece and are located on the first side, the first main tab is located in the straight area, and the first auxiliary tab is located in at least one corner area. Through setting up first main tab in flat district, set up first auxiliary tab in at least one corner district, improve overcurrent capacity and current density distribution's homogeneity.

Inventors

  • CHENG WEIXIANG
  • LI ZONGZHI
  • MENG CHUNLEI

Assignees

  • 欣旺达动力科技股份有限公司

Dates

Publication Date
20260508
Application Date
20250328

Claims (10)

  1. 1. A single cell having a first direction (X) and a second direction (Y) intersecting, characterized by comprising an electrode assembly (10); The electrode assembly (10) comprises a first pole piece (11), a diaphragm (13) and a second pole piece (12), wherein the first pole piece (11), the diaphragm (13) and the second pole piece (12) are stacked and wound, the electrode assembly (10) comprises a straight region (101) and two corner regions (102) connected with the straight region (101), the two corner regions (102) are respectively positioned on two opposite sides of the straight region (101) in the first direction (X), and the electrode assembly (10) comprises a first side (103) and a second side (104) which are oppositely arranged in the second direction (Y); The electrode assembly (10) further comprises a first main tab (14) and a first auxiliary tab (15) which are identical in polarity, wherein the first main tab (14) and the first auxiliary tab (15) are both connected to the first pole piece (11) and are both positioned on the first side (103), the first main tab (14) is positioned in the straight area (101), and the first auxiliary tab (15) is positioned in at least one corner area (102).
  2. 2. The single cell according to claim 1, wherein the first pole piece (11) comprises a first straight section (111) and a first corner section (112) connected, the first straight section (111) being provided with a plurality and being laminated at the straight section (101), the first corner section (112) being provided with a plurality and being laminated at the corner section (102); A plurality of first straight sections (111) are provided with the first main lugs (14), and a plurality of first corner sections (112) are provided with the first auxiliary lugs (15).
  3. 3. The unit cell according to claim 2, wherein the first electrode tab (11) has an unfolding direction (L), the first auxiliary tab (15) includes a plurality of first bending portions (151), the plurality of first bending portions (151) are connected to the same first corner section (112), the plurality of first bending portions (151) are disposed along the unfolding direction (L) of the first electrode tab (11), and at least two of the first bending portions (151) are stacked and electrically connected in the second direction (Y) after being bent when the electrode assembly (10) is in a wound state.
  4. 4. A single cell according to claim 3, wherein two adjacent first bent portions (151) located on the same first corner section (112) are arranged in a stacked manner in the second direction (Y); and/or, the first folded portions (151) of the adjacent two layers of the first corner sections (112) located in the same corner region (102) are stacked in the second direction (Y).
  5. 5. A unit cell according to claim 3, wherein the first auxiliary tab (15) is provided with a plurality of slits (150), the slits (150) are arranged at intervals along the unfolding direction (L) of the first pole piece (11), and one slit (150) is arranged between two adjacent first bending parts (151).
  6. 6. A cell according to claim 3, characterized in that the first corner sections (112) of each layer are provided with the first auxiliary tab (15), the length of the first auxiliary tab (15) in the direction of development (L) being equal to the length of the first corner sections (112) in the direction of development (L).
  7. 7. The unit cell according to claim 6, characterized in that the first straight section (111) of each layer is provided with the first main tab (14), and the first main tab (14) is folded and laminated in the second direction (Y) when the electrode assembly (10) is in a wound state.
  8. 8. The unit cell according to claim 7, characterized in that the first pole piece (11) further comprises a first electrodeless ear segment (100), the first electrodeless ear segment (100) is located at a winding start end of the first pole piece (11), the first electrodeless ear segment (100) is connected with the first straight segment (111) or the first corner segment (112), and the first electrodeless ear segment (100) is wound at least two turns.
  9. 9. The unit cell according to claim 8, characterized in that the lengths of the first main tab (14) and the first straight section (111) in the first direction (X) are equal; The first auxiliary tab (15) further comprises a first base (152), the first base (152) is connected between the first corner section (112) and the first bending part (151), the lengths of the first base (152) and the corresponding first corner section (112) in the unfolding direction (L) of the first pole piece (11) are equal, and the first base (152) is connected with the first main tab (14).
  10. 10. The unit cell according to any one of claims 1-9, wherein the electrode assembly (10) further comprises a second main tab (16) and a second auxiliary tab (17), the second main tab (16) and the second auxiliary tab (17) are both provided on the second pole piece (12), and the polarities of the second main tab (16) and the second auxiliary tab are the same and are both located on the second side (104), the polarity of the second main tab (16) is opposite to the polarity of the first main tab (14), the second main tab (16) is located in the flat region (101), and the second auxiliary tab (17) is located in the corner region (102) of at least one.

Description

Single battery Technical Field The application belongs to the technical field of batteries, and particularly relates to a single battery. Background The lithium ion power battery has the advantages of small volume, large capacity, high energy density, high charge-discharge multiplying power, excellent low-temperature performance, long service life, high safety and the like. Each ring layer of the conventional square power aluminum shell battery is only provided with one large tab by die cutting, and the overcurrent capacity is insufficient. Disclosure of utility model The embodiment of the utility model provides a single battery, which aims to solve the technical problem of insufficient overcurrent capacity of the current power battery. The single battery disclosed by the embodiment of the application is provided with a first direction and a second direction which are intersected, and the single battery comprises an electrode assembly; The electrode assembly comprises a first pole piece, a diaphragm and a second pole piece, wherein the first pole piece, the diaphragm and the second pole piece are laminated and wound, the electrode assembly comprises a straight area and two corner areas connected with the straight area, the two corner areas are respectively positioned on two opposite sides of the straight area in the first direction, and the electrode assembly comprises a first side and a second side which are oppositely arranged in the second direction; The electrode assembly further comprises a first main tab and a first auxiliary tab with the same polarity, wherein the first main tab and the first auxiliary tab are connected to the first pole piece and are located on the first side, the first main tab is located in the straight area, and the first auxiliary tab is located in at least one corner area. In some embodiments, the first pole piece comprises a first straight section and a first corner section connected, the first straight section being provided with a plurality and being laminated at the straight section, the first corner section being provided with a plurality and being laminated at the corner section; The plurality of first straight sections are provided with first main lugs, and the plurality of first corner sections are provided with first auxiliary lugs. In some embodiments, the first electrode tab has an unfolding direction, the first auxiliary tab includes a plurality of first bending portions, the plurality of first bending portions are connected to the same first corner section, the plurality of first bending portions are arranged along the unfolding direction of the first electrode tab, and when the electrode assembly is in a winding state, at least two first bending portions are arranged in a stacked manner in the second direction after being bent and electrically connected. In some embodiments, two adjacent first bending parts positioned on the same first corner section are stacked in the second direction; And/or, the first bending parts of the two adjacent layers of the first corner sections positioned in the same corner region are stacked in the second direction. In some embodiments, the first auxiliary tab is provided with a plurality of slits, the slits are spaced along the unfolding direction of the first pole piece, and one slit is arranged between two adjacent first bending parts. In some embodiments, the first corner section of each layer is provided with the first auxiliary tab, the length of the first auxiliary tab in the expanding direction being equal to the length of the first corner section in the expanding direction. In some embodiments, the first straight section of each layer is provided with the first main tab, which is bent and stacked in the second direction when the electrode assembly is in a wound state. In some embodiments, the first pole piece further comprises a first tab-free segment located at a winding start end of the first pole piece, the first tab-free segment is connected with the first straight segment or the first corner segment, and the first tab-free segment is wound at least two turns. In some embodiments, the first main tab and the first straight section are equal in length in the first direction; The first auxiliary tab further comprises a first base portion, the first base portion is connected between the first corner section and the first bending portion, the lengths of the first base portion and the corresponding first corner section in the unfolding direction of the first pole piece are equal, and the first base portion is connected with the first main tab. In some embodiments, the electrode assembly further includes a second main tab and a second auxiliary tab, the second main tab and the second auxiliary tab are both disposed on the second pole piece, and the polarities of the second main tab and the second auxiliary tab are the same and are both located on the second side, the polarity of the second main tab is opposite to the polarity of