Square battery

Abstract

According to the square battery provided by the utility model, the first battery cell and the second battery cell are respectively provided with the two first tabs and the two second tabs, and the two first tabs and the two second tabs are mutually staggered; the first distance between the two first tabs and the second distance between the two second tabs are designed to be the same or different, so that after the first battery cell and the second battery cell are stacked, the first tabs and the second tabs can be staggered from each other and are respectively positioned at different positions of the corresponding pole columns; and the stacking thickness of the tabs at a single position after the battery cells are stacked is reduced, so that the welding difficulty of the tabs is reduced, and the energy density is effectively improved.

Description

Technical Field

[0001] The utility model relates to a secondary battery comprising a plurality of battery cores, in particular to a square battery in which the tabs of at least a part of the battery cores are mutually staggered. Background Art

[0002] In response to the booming new energy vehicle market, power batteries are one of the three core technologies of new energy electric vehicles. Therefore, with the widespread use of power batteries, new energy vehicle manufacturers have put forward lightweight requirements to increase driving range, in order to extend its driving range as much as possible under limited space and power capacity, so as to make the expansion of new energy vehicles smoother.

[0003] The square battery 10 of the prior art, as shown in FIG1 , can be composed of a plurality of stacked battery cells 11. After stacking, the tabs 12 of each battery cell 11 are folded and stacked, and then welded to the metal connecting plate 13 together, so that the pole 14 can be welded thereon. However, as the number of stacked battery cells 11 increases to achieve sufficient electrical performance, the number of tabs 12 will also increase. In order to ensure that each tab 12 can be welded, the difficulty of welding will also increase. At the same time, the number of tabs 12 will also affect the thickness occupied by the tabs 12 after stacking, thereby reducing the energy density per unit volume of the overall square battery 10; furthermore, the heat generated by the tabs 12 will increase under high current charging and discharging conditions, which is also likely to cause battery safety problems.

[0004] Based on the above deficiencies of the prior art, the present invention proposes a square battery to effectively solve the above problems. Utility Model Content

[0005] The main purpose of the utility model is to provide a square battery, which can greatly reduce the thickness of the stacked tabs at a single position by utilizing the staggered tab design, thereby reducing the difficulty of welding and avoiding the problems of reduced energy density and safety caused by increased thickness.

[0006] The utility model provides a square battery, which is composed of a plurality of battery cell stacks, and includes: a plurality of first battery cells and a plurality of second battery cells, each of the first battery cells having a first positive electrode tab and a first negative electrode tab, and each of the second battery cells having a second positive electrode tab and a second negative electrode tab; a positive electrode column, which is electrically connected to the first positive electrode tab and the second positive electrode tab, and the first positive electrode tab and the second positive electrode tab are located on different sides of the positive electrode column; and a negative electrode column, which is electrically connected to the first negative electrode tab and the second negative electrode tab, and the first negative electrode tab and the second negative electrode tab are located on different sides of the negative electrode column.

[0007] Preferably, the first positive electrode tab and the first negative electrode tab have a first distance, the second positive electrode tab and the second negative electrode tab have a second distance, and the first distance is less than or equal to the second distance.

[0008] Preferably, the first battery cell and the second battery cell are stacked, the first positive electrode tab and the second positive electrode tab are misaligned, and the first negative electrode tab and the second negative electrode tab are misaligned.

[0009] Preferably, the first positive electrode tab and the first negative electrode tab are located between the positive electrode column and the negative electrode column.

[0010] Preferably, only one of the first positive electrode tab and the first negative electrode tab is located between the positive electrode column and the negative electrode column, and only one of the second positive electrode tab and the second negative electrode tab is located between the positive electrode column and the negative electrode column.

[0011] Preferably, the first battery cells and the second battery cells are stacked on each other in a uniaxial direction in a sequential arrangement.

[0012] Preferably, it also includes a positive electrode metal connecting plate and a negative electrode metal connecting plate, wherein the positive electrode metal connecting plate is electrically connected to the first positive electrode lug, the second positive electrode lug and the positive electrode column, and the negative electrode metal connecting plate is electrically connected to the first negative electrode lug, the second negative electrode lug and the negative electrode column.

[0013] Preferably, the first positive electrode tab and the first negative electrode tab are on the same side of a cell body of the first battery cell, and the second positive electrode tab and the second negative electrode tab are on the same side of a cell body of the second battery cell.

[0014] Preferably, the cell body of the first cell and the cell body of the second cell have the same size.

[0015] By dividing the battery cell into two different specifications of tabs, the tabs are offset and arranged on both sides of the pole, thereby greatly reducing the thickness of the tabs at a single position after stacking, thereby improving the energy density of the overall battery, reducing the difficulty of welding, and enhancing the safety of the battery, and can also reduce resistance and increase current.

[0016] The following detailed description is made through specific embodiments, so that the purpose, technical content, characteristics and effects achieved by the present invention can be more easily understood. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 is a schematic diagram of a square battery in the prior art.

[0018] Figure 2A , 2B It is a schematic diagram of the first and second battery cells of the square battery of the utility model.

[0019] Figure 3 It is a schematic diagram of the battery cell stack of the square battery of the utility model.

[0020] Figure 4 It is a schematic diagram of welding and fixing the tabs of the square battery of the utility model.

[0021] Figure 5A , 5B It is a schematic diagram of another embodiment of the first and second battery cells of the square battery of the utility model.

[0022] Figure 5C It is a schematic diagram of the welding and fixing of the tabs of the first and second battery cells of another embodiment of the square battery of the utility model.

[0023] Figure 6 It is a cross-sectional schematic diagram of a square battery of the utility model.

[0024] Fig. 7A , 7B This is a schematic diagram of the utility model square battery applied to an aluminum shell.

[0025] Reference numerals

[0026] 10 square battery

[0027] 11 Battery Cell

[0028] 12 Tabs

[0029] 13 Metal connecting plate

[0030] 14 pole

[0031] 20 square batteries

[0032] 21 First Cell

[0033] 211 First positive electrode tab

[0034] 212 First negative electrode tab

[0035] 22 Second battery cell

[0036] 221 Second positive electrode tab

[0037] 222 Second negative electrode tab

[0038] 30 Positive metal connecting piece

[0039] 32 Negative metal connecting piece

[0040] 40 Positive pole

[0041] 42 Negative pole

[0042] 70 Aluminum Shell

[0043] 71 Pressure relief valve

[0044] 72 Vacuum holes

[0045] D1 first spacing

[0046] D2 Second spacing DETAILED DESCRIPTION

[0047] In order to make the advantages, spirit and features of the present invention easier to understand, the following will be described and discussed in detail with reference to the embodiments and drawings. It should be stated that these embodiments are only representative embodiments of the present invention, and the implementation and protection scope of the present invention are not limited to these embodiments. The purpose of providing these embodiments is only to make the disclosure of the present invention more thorough and easy to understand.

[0048] The terms used in the various embodiments disclosed in the present invention are only used for the purpose of describing specific embodiments and are not intended to limit the various embodiments disclosed in the present invention. Unless otherwise clearly indicated, the singular form used also includes the plural form. Unless otherwise specified, all terms (including technical terms and scientific terms) used in this specification have the same meanings as those generally understood by those skilled in the art in the various embodiments disclosed in the present invention. The above terms (such as those defined in a generally used dictionary) will be interpreted as having the same meaning as the contextual meaning in the same technical field, and will not be interpreted as having an idealized meaning or an overly formal meaning unless clearly defined in the various embodiments disclosed in the present invention.

[0049] In the description of this specification, the reference to the terms "an embodiment", "a specific embodiment", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment are included in at least one embodiment of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments in a suitable manner.

[0050] In the description of the present invention, unless otherwise specified or limited, it should be noted that the terms "coupling", "connection" and "setting" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection of two components, it can be a direct connection, or it can be connected through an intermediate medium. For those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0051] Considering the prior art square battery stacking, the thickness of the tab stack increases significantly as the number of stacks increases. Therefore, the present invention displaces the tabs to reduce the thickness of the tab stack. The square battery disclosed in the present invention is first referred to as Figure 2A , 2B , including a first battery cell 21 and a second battery cell 22, the battery cell bodies (i.e., the parts without tabs) of the first battery cell 21 and the second battery cell 22 are the same size, the first battery cell 21 has a first positive tab 211 and a first negative tab 212, and the first positive tab 211 and the first negative tab 212 can be located on the same side of the battery cell body of the first battery cell 21 (as shown in the figure, they are above the battery cell body), the second battery cell 22 has a second positive tab 221 and a second negative tab 222, and the second positive tab 221 and the second negative tab 222 can be located on the same side of the battery cell body of the second battery cell 22 (as shown in the figure, they are above the battery cell body). There is a first spacing D1 between the first positive tab 211 and the first negative tab 212 of the first battery cell 21; there is a second spacing D2 between the second positive tab 221 and the second negative tab 222 of the second battery cell 22. After the first battery cell 21 and the second battery cell 22 are stacked, the first positive electrode tab 211 and the first negative electrode tab 212 are offset from the second positive electrode tab 221 and the second negative electrode tab 222 , that is, the tabs are not overlapped, and the first spacing D1 is smaller than the second spacing D2 .

[0052] Please refer to Figure 3 The square battery 20 of the utility model is formed by stacking the aforementioned plurality of first battery cells 21 and the plurality of second battery cells 22. As mentioned above, the first positive electrode tab 211 and the first negative electrode tab 212 and the second positive electrode tab 221 and the second negative electrode tab 222 are mutually offset, so that the thickness can be greatly reduced (detailed later), and the first spacing D1 between the first positive electrode tab 211 and the first negative electrode tab 212 of the first battery cell 21 is smaller than the spacing D2 between the second positive electrode tab 221 and the second negative electrode tab 222 of the second battery cell 22. 22 has a second spacing D2; as shown in the figure, a first battery cell 21 and a second battery cell 22 are arranged in sequence to be stacked, however, the utility model is not limited to being arranged in this way, the first battery cell 21 and the second battery cell 22 can be arranged in any configuration, or their numbers can be different, and the purpose of reducing the stacking thickness by staggering the first positive electrode tab 211 and the first negative electrode tab 212 and the second positive electrode tab 221 and the second negative electrode tab 222 can also be achieved.

[0053] like Figure 4As shown, after a plurality of first cells 21 and a plurality of second cells 22 are stacked, the first positive electrode tab 211 of the first cell 21 and the second positive electrode tab 221 of the second cell 22 are folded and stacked, and after being connected by the positive metal connecting sheet 30 (generally by welding), the positive electrode column 40 is connected to the positive metal connecting sheet 30. The positive electrode column 40 can be a conductor made of a metal material, and is electrically connected to the positive metal connecting sheet 30 and the first positive electrode tab 211 and the second positive electrode tab 221 as a conductive terminal. Similarly, the first negative electrode tab 212 of the first cell 21 and the second negative electrode tab 222 of the second cell 22 are folded and stacked, and after being connected by the negative metal connecting sheet 32 ​​(generally by welding), the negative electrode column 42 is connected to the negative metal connecting sheet 32. The negative pole post 42 can be a metal conductor, electrically connected to the negative metal connecting sheet 32 ​​and the first negative pole tab 212 and the second negative pole tab 222, as a conductive terminal. The first spacing D1 between the first positive pole tab 211 and the first negative pole tab 212 of the first battery cell 21 is smaller than the second spacing D2 between the second positive pole tab 221 and the second negative pole tab 222 of the second battery cell 22. Therefore, the first positive pole tab 211 and the second positive pole tab 221 are mutually displaced, and the first negative pole tab 212 and the second negative pole tab 222 are mutually displaced. The first positive pole tab 211 and the first negative pole tab 212 of the first battery cell 21 will be located between the positive pole post 40 and the negative pole post 42 (here defined as the inner side of the positive pole 40 and the negative pole 42), and the second positive pole tab 221 and the second negative pole tab 222 of the second battery cell 22 are located on the other side of the positive pole 40 and the negative pole 42 (here defined as the outer side of the positive pole 40 and the negative pole 42), that is, the first positive pole tab 211 and the second positive pole tab 221 are located on different sides of the positive pole 40, and the first negative pole tab 212 and the second negative pole tab 222 are located on different sides of the negative pole 42. Based on the same principle, please refer to Figure 5A , 5B , 5C, in other embodiments of the present invention, on the premise that the first positive electrode tab 211 and the second positive electrode tab 221, as well as the first negative electrode tab 212 and the second negative electrode tab 222 are mutually offset, the first spacing D1 between the first positive electrode tab 211 and the first negative electrode tab 212 of the first battery cell 21 can be designed to be roughly equal to the second spacing D2 between the second positive electrode tab 221 and the second negative electrode tab 222 of the second battery cell 22. Therefore, after subsequent stacking, the first positive electrode tab 211 of the first battery cell 21 will be located on the left side of the positive electrode column 40, the first negative electrode tab 212 will be located on the left side of the negative electrode column 42, and the second positive electrode tab 221 of the second battery cell 22 will be located on the right side of the positive electrode column 40, and the second negative electrode tab 222 will be located on the right side of the negative electrode column 42.

[0054] Therefore, please also refer to Figure 4 ,6 Because the design divides the tabs into a first positive tab 211 and a first negative tab 212 and a second positive tab 221 and a second negative tab 222, from the perspective of one side of the pole (such as the left side or right side of the positive pole 40 or the negative pole 42 as shown in the figure), the number of stacked tabs will be reduced by half, so the stack thickness can be reduced by about half; for example, with the same number of battery cells, for single-polarity tabs, the number of first positive tabs 211 of the first battery cell 21 or the second positive tabs 221 of the second battery cell 22 stacked at the same place will be half of the number of original stacked tabs, so the folded thickness can also be reduced by half; the same principle applies to the first negative tab 212 of the first battery cell 21 or the second negative tab 222 of the second battery cell 22 on the other side. Therefore, the stack thickness of the first positive electrode tab 211 or the second positive electrode tab 221 that needs to be welded to the positive metal connecting plate 30 on one side of the positive electrode column 40 can also be reduced by half. On the other hand, the stack thickness of the first negative electrode tab 212 or the second negative electrode tab 222 that needs to be welded to the negative metal connecting plate 32 on one side of the negative electrode column 42 can also be reduced by half, which will greatly reduce the difficulty of welding. At the same time, because the first positive electrode tab 211 or the second positive electrode tab 221 and the first negative electrode tab 212 or the second negative electrode tab 222 are separated into two parts, the current can be effectively dispersed, the temperature rise under long-term use can be reduced, and the resistance value can be effectively reduced.

[0055] Please refer to Fig. 7A , 7B When the aluminum shell 70 is used for packaging, the square battery 20 (for example Figure 4 The positive electrode column 40 and the negative electrode column 42 are packaged, and the top surfaces are exposed to form electrodes for external output, and the packaging of the aluminum shell battery is completed in conjunction with the arrangement of the pressure relief valve 71 and the vacuum hole 72; at this time, since the thickness of the first positive electrode tab 211 or the second positive electrode tab 221, and the first negative electrode tab 212 or the second negative electrode tab 222 after stacking is reduced (by about half), the space occupied by the first positive electrode tab 211 or the second positive electrode tab 221, and the first negative electrode tab 212 or the second negative electrode tab 222 above the aluminum shell 70 can be reduced, thereby improving the energy density of the overall aluminum shell battery.

[0056] In summary, the utility model proposes a square battery 20, which divides the battery cells into a first battery cell 21 and a second battery cell 22, and the first positive electrode tab 211 and the first negative electrode tab 212 of the first battery cell 21 and the second positive electrode tab 221 and the second negative electrode tab 222 of the second battery cell 22 are offset from each other, and the first spacing D1 between the first positive electrode tab 211 and the first negative electrode tab 212 is designed to be the same as or smaller than the second spacing D2 between the second positive electrode tab 221 and the second negative electrode tab 222, so that the thickness of the stacked tabs can be greatly reduced, and the number of tabs required to be welded at a single position can be effectively reduced to reduce the welding difficulty. At the same time, the current can be effectively dispersed, the temperature rise under long-term use can be reduced, and the resistance value can be effectively reduced; in subsequent applications, the energy density of the overall battery can be improved due to the reduction in the total stacking thickness of the tabs at a single position.

[0057] The above is only a preferred embodiment of the utility model, and is not intended to limit the scope of the utility model. Therefore, all equivalent changes or modifications based on the features and spirit described in the claims of the utility model should be included in the scope of the patent application of the utility model.

Claims

1. A square battery, characterized in that: The square battery is composed of multiple battery stacks, including: A plurality of first battery cells and a plurality of second battery cells, each of the first battery cells having a first positive electrode tab and a first negative electrode tab, and each of the second battery cells having a second positive electrode tab and a second negative electrode tab; a positive electrode post electrically connecting the first positive electrode tab and the second positive electrode tab, wherein the first positive electrode tab and the second positive electrode tab are located on different sides of the positive electrode post; and A negative electrode column is electrically connected to the first negative electrode tab and the second negative electrode tab. The first negative electrode tab and the second negative electrode tab are located on different sides of the negative electrode column.

2. The square battery according to claim 1, characterized in that: The first positive electrode tab and the first negative electrode tab have a first distance, the second positive electrode tab and the second negative electrode tab have a second distance, and the first distance is less than or equal to the second distance.

3. The square battery according to claim 1, characterized in that: The first battery cell and the second battery cell are stacked, the first positive electrode tab and the second positive electrode tab are misaligned, and the first negative electrode tab and the second negative electrode tab are misaligned.

4. The square battery according to claim 1, characterized in that: The first positive electrode tab and the first negative electrode tab are located between the positive electrode column and the negative electrode column.

5. The square battery according to claim 1, characterized in that: Only one of the first positive electrode tab and the first negative electrode tab is located between the positive electrode column and the negative electrode column, and only one of the second positive electrode tab and the second negative electrode tab is located between the positive electrode column and the negative electrode column.

6. The square battery according to claim 1, characterized in that: The first battery cells and the second battery cells are stacked on each other in a uniaxial manner in a sequential arrangement.

7. The square battery according to claim 1, characterized in that: It also includes a positive metal connecting plate and a negative metal connecting plate, wherein the positive metal connecting plate is electrically connected to the first positive electrode ear, the second positive electrode ear and the positive electrode column, and the negative metal connecting plate is electrically connected to the first negative electrode ear, the second negative electrode ear and the negative electrode column.

8. The square battery according to claim 1, characterized in that: The first positive electrode tab and the first negative electrode tab are on the same side of a cell body of the first cell, and the second positive electrode tab and the second negative electrode tab are on the same side of a cell body of the second cell.

9. The square battery according to claim 1, characterized in that: The cell body of the first cell and the cell body of the second cell have the same size.

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