Cell hot pressing device and cell

Abstract

The present invention discloses a battery cell hot pressing device and a battery cell. Among them, the battery cell hot pressing device is used for hot pressing a bare battery cell, and includes a driving device for providing driving force, a support platform for placing the battery cell, a first hot pressing assembly, and a second hot pressing assembly. Both ends of the bare battery cell extend beyond both ends of the support platform. The first hot pressing assembly includes a first upper hot pressing member and a first lower hot pressing member that cooperate to hot press one end of the glue application area of the bare battery cell, so that the negative electrode sheet, the separator, and the positive electrode sheet in this glue application area are combined. The second hot pressing assembly includes a second upper hot pressing member and a second lower hot pressing member that cooperate to hot press the glue application area at the other end of the battery cell, so that the negative electrode sheet, the separator, and the positive electrode sheet in this glue application area are combined, making the thickness of the glue application area after hot pressing different, and ensuring the hot pressing effect. The technical solution of the present invention can hot press the specific glue application area of the battery cell, ensure a good hot pressing effect, avoid the misalignment of the positive and negative electrode sheets, and at the same time reduce the cost of the battery cell.

Description

Technical Field

[0001] The present invention relates to the technical field of battery production equipment, and particularly relates to a core hot pressing device and a core. Background Art

[0002] In the existing solutions, for core manufacturing, a coated separator is mostly used for lamination or winding, and then flat hot pressing is carried out. On the one hand, the cost of using a coated separator is relatively high. On the other hand, hot pressing is likely to cause blockage of the separator pores, further resulting in an increase in the internal resistance of the core and a reduction in the power performance of the core. When using a non-coated separator, glue needs to be applied to the empty foil areas at the top and bottom ends of the electrode sheet, and the coated area is bonded to the separator through hot pressing, thereby achieving a fixing effect to prevent the electrode sheet from sliding. However, the existing hot pressing equipment can only perform overall hot pressing on the large surface of the core and cannot perform hot pressing on specific positions of the coated area. Summary of the Invention

[0003] The main purpose of the present invention is to provide a core hot pressing device, aiming to provide a core hot pressing device that can perform hot pressing on the specific coated area of a core, ensure a good hot pressing effect, avoid misalignment of the positive and negative electrode sheets, and reduce the cost of the core at the same time.

[0004] To achieve the above object, the present invention provides a core hot pressing device for hot pressing a bare core. The bare core includes a negative electrode sheet, a separator, and a positive electrode sheet that are sequentially stacked. The bare core includes a coated area and a non-coated area. Among them, the coated area includes a first coated area provided at one end of the bare core and a second coated area provided at the other end, and the middle part is a non-coated area. The thickness of the coated area is less than the thickness of the non-coated area. The core hot pressing device includes:

[0005] A driving device for providing driving force;

[0006] A support platform for placing the core, and both ends of the bare core extend beyond both ends of the support platform;

[0007] A first hot pressing assembly provided at one end of the support platform. The first hot pressing assembly includes a first upper hot pressing member and a first lower hot pressing member that are arranged opposite to each other up and down and are connected to the driving device. The first upper hot pressing member and the first lower hot pressing member cooperate to hot press the first coated area of the bare core, so that the negative electrode sheet, the separator, and the positive electrode sheet in the first coated area are combined; and

[0008] A second hot pressing assembly provided at the other end of the support platform. The second hot pressing assembly includes a second upper hot pressing member and a second lower hot pressing member that are arranged opposite to each other up and down and are connected to the driving device. The second upper hot pressing member and the second lower hot pressing member cooperate to hot press the second coated area of the bare core, so that the negative electrode sheet, the separator, and the positive electrode sheet in the second coated area are combined.

[0009] Optionally, the first upper hot pressing member includes a first upper pressing member connected to the driving device and a first upper hot pressing portion provided on the first upper pressing member. The first lower hot pressing member includes a first lower pressing member connected to the driving device and a first lower hot pressing portion correspondingly arranged with the first upper hot pressing portion. The first upper hot pressing portion and the first lower hot pressing portion cooperate to hot press the first glue-applying area of the bare battery cell, so that the first glue-applying area has different hot pressing thicknesses;

[0010] The second upper hot pressing member includes a second upper pressing member connected to the driving device and a second upper hot pressing portion provided on the second upper pressing member. The second lower hot pressing member includes a second lower pressing member connected to the driving device and a second lower hot pressing portion correspondingly arranged with the second upper hot pressing portion. The second upper hot pressing portion and the second lower hot pressing portion cooperate to hot press the second glue-applying area of the bare battery cell, so that the second glue-applying area has different hot pressing thicknesses.

[0011] Optionally, the first glue-applying area includes a first positive glue section provided on the positive electrode plate near its tab foil and a first bonding section provided on the negative electrode plate away from its tab foil. The first positive glue section includes a first left glue section and a second left glue section. The first left glue section corresponds to the first bonding section, and the second left glue section extends beyond the first bonding section;

[0012] The first upper hot pressing portion is formed with a first upper step, and the first lower hot pressing portion is formed with a first lower step that cooperates with the first upper step. The first upper step includes a left first upper pressing surface and a left second upper pressing surface, and the first lower step includes a left first lower pressing surface and a left second lower pressing surface. The left first upper pressing surface and the left first lower pressing surface cooperate to hot press the first left glue section and the first bonding section, and the left second upper pressing surface and the left second lower pressing surface cooperate to hot press the second left glue section, so that the hot pressing thickness of the first glue-applying area decreases in the direction close to the tab foil of the positive electrode plate.

[0013] Optionally, the first glue-applying area includes a first positive glue section provided on the positive electrode plate near its tab foil, a first bonding section provided on the negative electrode plate away from its tab foil, and a second negative glue section provided on the negative electrode plate and outside the first bonding section. The first positive glue section includes a first left glue section, a second left glue section, and a third left glue section. The first left glue section corresponds to the first bonding section, the second left glue section corresponds to the second negative glue section, and the third left glue section extends beyond the second negative glue section. The thickness of the first bonding section is greater than the thickness of the second negative glue section;

[0014] The first upper hot pressing part is formed with a first upper step, and a first lower step matching with the first upper step is formed on the first lower hot pressing part. The first upper step includes a left first upper pressing surface, a left second upper pressing surface and a left third upper pressing surface. The first lower step includes a left first lower pressing surface, a left second lower pressing surface and a left third lower pressing surface. The left first upper pressing surface and the left first lower pressing surface cooperate to hot press the first left glue segment and the first bonding segment. The left second upper pressing surface and the left second lower pressing surface cooperate to hot press the second left glue segment and the second negative glue area. The left third upper pressing surface and the left third lower pressing surface cooperate to hot press the third left glue segment, so that the thickness of the first glue application area decreases in the direction close to the pole tab foil of the positive electrode sheet during hot pressing.

[0015] Optionally, the second glue application area includes a second positive glue area provided on the positive electrode sheet away from its pole tab foil, a first negative glue area provided on the negative electrode sheet close to its pole tab foil, and a second bonding segment provided on the negative electrode sheet and inside the first negative glue area. The second positive glue area includes a first right glue segment and a second right glue segment. The first negative glue area includes a first negative glue segment and a second negative glue segment. The first right glue segment corresponds to the second bonding segment. The second right glue segment corresponds to the first negative glue segment. The second negative glue segment extends beyond the second right glue segment.

[0016] The second upper hot pressing part is formed with a second upper step, and a second lower step matching with the second upper step is formed on the second lower hot pressing part. The second upper step includes a right first upper pressing surface, a right second upper pressing surface and a right third upper pressing surface. The second lower step includes a right first lower pressing surface, a right second lower pressing surface and a right third lower pressing surface. The right first upper pressing surface and the right first lower pressing surface cooperate to hot press the first right glue segment and the second bonding segment. The right second upper pressing surface and the right second lower pressing surface cooperate to hot press the second right glue segment and the first negative glue segment. The left third upper pressing surface and the left third lower pressing surface cooperate to hot press the second negative glue segment, so that the thickness of the second glue application area decreases in the direction close to the pole tab foil of the negative electrode sheet during hot pressing.

[0017] Optionally, the first upper step and the first lower step are symmetrically arranged along a horizontal line, and the second upper step and the second lower step are symmetrically arranged along a horizontal line; and / or, the first upper step is symmetrically arranged with the second upper step along the center line of the support platform, and the first lower step is symmetrically arranged with the second lower step along the center line of the support platform.

[0018] Optionally, the battery cell hot pressing device includes at least two first hot pressing components and second hot pressing components corresponding to the number of the first hot pressing components. Both the first hot pressing components and the second hot pressing components are detachably connected to the driving device. The first upper step height and the first lower step height of different first hot pressing components are different. By replacing the first hot pressing components and the corresponding second hot pressing components, bare battery cells with different thicknesses of the first glue application area and the second glue application area are hot pressed; or

[0019] The battery cell hot pressing device includes a step pad, and the step pad can be detachably placed on the first upper step, the first lower step, the second upper step, and the second lower step to hot press bare battery cells with different thicknesses of the first glue application area and the second glue application area.

[0020] Optionally, a positioning part is provided on the support platform, and the positioning part is used to fix the battery cell.

[0021] The present invention also provides a battery cell, including a bare battery cell, and the bare battery cell is obtained by hot pressing using the above-mentioned battery cell hot pressing device.

[0022] Optionally, the second left glue section of the positive electrode sheet includes a positive electrode end glue area of the positive electrode sheet part and a positive electrode tab glue area of the positive electrode tab foil part;

[0023] Wherein, the width of the glue application layer of the positive electrode tab glue area is the width of the positive electrode tab, the height is 1-10 μm, and the thickness is 5-100 μm;

[0024] The width of the glue application layer of the positive electrode end glue area is the width of the positive electrode sheet, the height is 1-20 μm, and the thickness is 5-100 μm;

[0025] The width of the glue application layer of the first left glue section of the positive electrode sheet is the width of the positive electrode sheet, the height is 1-20 μm, and the thickness is 5-100 μm;

[0026] The width of the glue application layer of the first negative glue area of the negative electrode sheet is the width of the negative electrode tab, the height is 1-10 μm, and the thickness is 5-100 μm;

[0027] The width of the glue application layer of the second negative glue area of the negative electrode sheet is the width of the negative electrode sheet, the height is 1-20 μm, and the thickness is 5-100 μm.

[0028] The technical solution of the present invention adopts a first hot pressing assembly including a first upper hot pressing member and a first lower hot pressing member, and a second hot pressing assembly including a second upper hot pressing member and a second lower hot pressing member. The bare battery cell to be hot pressed is placed on the support platform. Driven by the driving device, the first upper hot pressing member and the first lower hot pressing member only hot press the first glue application area at one end of the bare battery cell, and the second upper hot pressing member and the second lower hot pressing member only hot press the second glue application area at the other end of the battery cell. When using the first hot pressing assembly and the second hot pressing assembly for hot pressing, the positions of the first glue application area and the second glue application area at the end of the battery cell can be hot pressed to ensure the bonding effect at the end, so as to achieve the purpose of fixing the battery cell pole pieces. After hot pressing, the negative electrode sheets, diaphragms and positive electrode sheets in the first glue application area and the second glue application area at each end of the battery cell are bonded. On the one hand, the diaphragm with end glue application reduces the overall impedance of the battery cell compared with the diaphragm with overall glue application; on the other hand, avoiding the use of the diaphragm with overall glue application reduces the cost of the battery cell; on the other hand, through the hot pressing of the glue application areas provided at both ends of the battery cell by the first hot pressing assembly and the second hot pressing assembly, a good hot pressing effect is ensured, and the misalignment of the positive and negative electrode sheets is avoided; space waste is reduced, and the utilization rate of the internal space of the battery cell is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0030] Figure 1 It is a schematic structural diagram of an embodiment of the bare battery cell of the present invention;

[0031] Figure 2 For Figure 1 It is a schematic structural diagram of the positive electrode sheet in the bare battery cell;

[0032] Figure 3 For Figure 1 It is a schematic structural diagram of the negative electrode sheet in the bare battery cell;

[0033] Figure 4 For the battery cell hot pressing device of the present invention to Figure 1 The schematic structural diagram before hot pressing the bare battery cell in;

[0034] Figure 5 For Figure 4 The battery cell hot pressing device in to Figure 1 The schematic structural diagram after hot pressing the bare battery cell in;

[0035] Figure 6 It is a schematic structural diagram of another embodiment of the bare battery cell of the present invention;

[0036] Figure 7 is Figure 6 Schematic diagram of the structure of the positive electrode plate in the bare battery cell;

[0037] Figure 8 is Figure 6 Schematic diagram of the structure of the negative electrode plate in the bare battery cell;

[0038] Figure 9 is the schematic diagram of the structure of the bare battery cell before hot pressing by the battery cell hot pressing device of another embodiment of the present invention Figure 6 in;

[0039] Figure 10 is Figure 9 in the battery cell hot pressing device for Figure 6 the schematic diagram of the structure of the bare battery cell after hot pressing in;

[0040] Explanation of the reference numerals in the drawings:

[0041]

[0042]

[0043] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] In the present invention, unless otherwise clearly defined and limited, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0046] In addition, in the present invention, descriptions such as "first", "second", etc. are for descriptive purposes only, and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments may be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0047] In the existing solutions, for the manufacturing of battery cells, a coated separator is mostly used for lamination or winding, followed by flat hot pressing. On the one hand, the use of a coated separator has a relatively high cost. On the other hand, hot pressing is likely to cause blockage of the separator pores, further increasing the internal resistance of the battery cell and reducing the power performance of the battery cell. When using an uncoated separator, glue needs to be applied to the empty foil areas at the top and bottom of the electrode sheet, and the coated area is bonded to the separator through hot pressing, thereby achieving a fixing effect to prevent the electrode sheet from sliding. However, the existing hot pressing equipment can only perform overall hot pressing on the large surface of the battery cell and cannot perform hot pressing on specific positions in the specific area of the coated area.

[0048] For this reason, the present invention proposes a battery cell hot pressing device.

[0049] Refer to Figures 1 to 10, in an embodiment of the present invention, the battery cell hot pressing device 100 is used to hot press a bare battery cell 200. The bare battery cell 200 includes a negative electrode sheet 400, a separator 500, and a positive electrode sheet 300 that are stacked in sequence. The bare battery cell 200 includes a glue application area and a non - glue application area 230. Among them, the glue application area includes a first glue application area 210 provided at one end of the bare battery cell 200 and a second glue application area 220 provided at the other end, and the middle part is the non - glue application area 230. The thickness of the glue application area is less than the thickness of the non - glue application area 230, that is, no glue application layer is provided in the middle parts of the positive electrode sheet 300 and the negative electrode sheet 400. The battery cell hot pressing device 100 includes: a driving device (not shown in the figure) for providing driving force, a support platform 10 for placing the battery cell, a first hot pressing assembly 20, and a second hot pressing assembly 50. The two ends of the battery cell extend beyond the two ends of the support platform 10; the first hot pressing assembly 20 is provided at one end of the support platform 10. The first hot pressing assembly 20 includes a first upper hot pressing member 30 and a first lower hot pressing member 40 that are arranged oppositely up and down and are connected to the driving device. The first upper hot pressing member 30 and the first lower hot pressing member 40 cooperate to hot press the first glue application area 210 of the bare battery cell 200, so that the negative electrode sheet 400, the separator 500, and the positive electrode sheet 300 in the first glue application area 210 are combined; the second hot pressing assembly 50 is provided at the other end of the support platform 10. The second hot pressing assembly 50 includes a second upper hot pressing member 60 and a second lower hot pressing member 70 that are arranged oppositely up and down and are connected to the driving device. The second upper hot pressing member 60 and the second lower hot pressing member 70 cooperate to hot press the second glue application area 220 of the bare battery cell 200, so that the negative electrode sheet 400, the separator 500, and the positive electrode sheet 300 in the second glue application area 220 are combined.

[0050] The commonly used lithium - battery separator is a composite glue - coated ceramic separator, about ten - plus micrometers. The composite glue - coated ceramic separator includes a base film, a glue application layer, and a ceramic layer. The base film is a composite layer of PE and PP. The glue application layer is to make the electrode sheet and the base film fit better, and the ceramic layer is to make it have better rigidity and shrinkage resistance. However, there are two problems as follows. On the one hand, the cost of using the glue - coated separator is relatively high. On the other hand, overall hot pressing is likely to cause the pores of the glue - coated separator to be blocked, further causing the internal resistance of the battery cell to increase and reducing the power performance of the battery cell. The non - glue - coated separator, that is, the glue application layer is only provided in some areas of the base film, thus greatly reducing the production cost. In order to hot press specific positions in the specific area of the glue application area to ensure the fixing effect of the separator 500 and prevent the electrode sheet from sliding. In this solution, the first hot pressing assembly 20 and the second hot pressing assembly 50 hot press the glue application areas at both ends under the drive of the driving device. The driving device can refer to the prior art and will not be introduced in detail here.

[0051] The technical solution of the present invention is that the first hot pressing assembly 20 includes a first upper hot pressing member 30 and a first lower hot pressing member 40, and the second hot pressing assembly 50 includes a second upper hot pressing member 60 and a second lower hot pressing member 70. The bare battery cell 200 to be hot pressed is placed on the support platform 10. Driven by the driving device, the first upper hot pressing member 30 and the first lower hot pressing member 40 only hot press the first glue application area 210 at one end of the bare battery cell 200, and the second upper hot pressing member 60 and the second lower hot pressing member 70 only hot press the second glue application area 220 at the other end of the battery cell. When using the first hot pressing assembly 20 and the second hot pressing assembly 50 for hot pressing, it is possible to hot press the positions of the first glue application area 210 and the second glue application area 220 at the end of the battery cell, ensuring the bonding effect at the end, so as to achieve the purpose of fixing the battery cell electrode tabs. After hot pressing, each glue application area at the end of the battery cell is bonded to the separator 500. On the one hand, compared with using a separator with overall glue application, the separator 500 with end glue application reduces the overall impedance of the battery cell; on the other hand, avoiding the use of a separator with overall glue application reduces the cost of the battery cell; on the further hand, by hot pressing the glue application areas provided at both ends of the battery cell by the first hot pressing assembly 20 and the second hot pressing assembly 50, a good hot pressing effect is ensured, and the misalignment of the positive and negative electrode tabs 400 is avoided; space waste is reduced, and the utilization rate of the internal space of the battery cell is improved.

[0052] Referring to Figures 1 to 3 and Figures 6 to 8 , in order to improve the hot pressing effect, make the glue application areas at the end of the battery cell have different thicknesses, ensure the hot pressing effect, and avoid the misalignment of the positive and negative electrode tabs 400, the first glue application area 210 includes a first positive glue segment 310 close to the tab foil of the positive electrode tab 300, the second glue application area 220 includes a second positive glue segment 320 away from the tab foil of the positive electrode tab 300 and a first negative glue segment 410 close to the tab foil of the negative electrode tab 400; the non-glue application area 230 of the negative electrode tab 400 includes a first bonding segment 430 away from the first negative glue segment 410 and a second bonding segment 440 close to the first negative glue segment 410. The first positive glue segment 310 includes a first left glue segment 311 and a second left glue segment 312. The first left glue segment 311 corresponds to the first bonding segment 430, and the second left glue segment 312 extends beyond the first bonding segment 430. The second positive glue segment 320 includes a first right glue segment 321 and a second right glue segment 322. The first negative glue segment 410 includes a first negative glue segment 411 and a second negative glue segment 412. The first right glue segment 321 corresponds to the second bonding segment 440, the second right glue segment 322 corresponds to the first negative glue segment 411, and the second negative glue segment 412 extends beyond the second right glue segment 322.

[0053] The first upper hot pressing member 30 includes a first upper pressing member connected to a driving device, and a first upper hot pressing portion provided on the first upper pressing member. The first lower hot pressing member 40 includes a first lower pressing member connected to the driving device, and a first lower hot pressing portion disposed corresponding to the first upper hot pressing portion. The first upper hot pressing portion and the first lower hot pressing portion cooperate to hot press a first gluing area 210 of the bare battery cell 200, so that the first gluing area 210 has different hot pressing thicknesses.

[0054] The second upper hot pressing member 60 includes a second upper pressing member connected to a driving device, and a second upper hot pressing portion provided on the second upper pressing member. The second lower hot pressing member 70 includes a second lower pressing member connected to the driving device, and a second lower hot pressing portion disposed corresponding to the second upper hot pressing portion. The second upper hot pressing portion and the second lower hot pressing portion cooperate to hot press a second gluing area 220 of the bare battery cell 200, so that the second gluing area 220 has different hot pressing thicknesses.

[0055] The bare battery cell 200 is laminated by a positive electrode plate 300, a separator 500 and a negative electrode plate 400. The ends of the positive electrode plate 300 and the negative electrode plate 400 have different thicknesses. For example, the thickness of the first bonding section 430 is greater than the thickness of the second negative glue area 420. The staggered arrangement of the positive electrode plate 300 and the negative electrode plate 400 makes the thickness different along the extending direction of both ends of the bare battery cell 200. In order to ensure the hot pressing effect between different thicknesses at the ends of the bare battery cell 200, ensure good hot pressing bonding for different thickness changes in the extending direction, and ensure the quality of the bare battery cell 2000, the solution of the battery cell hot pressing device 100 is introduced below.

[0056] Refer to Figures 1 to 5 In an embodiment, a first upper step 31 is formed on the first upper hot pressing portion, and a first lower step 41 that cooperates with the first upper step 31 is formed on the first lower hot pressing portion. The first upper step 31 includes a left first upper pressing surface 32 and a left second upper pressing surface 33. The first lower step 41 includes a left first lower pressing surface 42 and a left second lower pressing surface 43. The left first upper pressing surface 32 and the left first lower pressing surface 42 cooperate to hot press the first left glue section 311 and the first bonding section 430. The left second upper pressing surface 33 and the left second lower pressing surface 43 cooperate to hot press the second left glue section 312, so that the first gluing area 210 has different hot pressing thicknesses.

[0057] Refer to Figures 6 to 10, in another embodiment, the first glue application area 210 further includes a second negative glue area 420 away from the first negative glue area 410. The first positive glue area 310 further includes a third left glue segment 313. The first left glue segment 311 corresponds to the first bonding segment 430. The second left glue segment 312 corresponds to the second negative glue area 420. The third left glue segment 313 extends beyond the second negative glue area 420. The first upper hot pressing part is formed with a first upper step 31, and the first lower hot pressing part is formed with a first lower step 41 that cooperates with the first upper step 31. The first upper step 31 includes a left first upper pressing surface 32, a left second upper pressing surface 33, and a left third upper pressing surface 34. The first lower step 41 includes a left first lower pressing surface 42, a left second lower pressing surface 43, and a left third lower pressing surface 44. The left first upper pressing surface 32 and the left first lower pressing surface 42 cooperate to hot press the first left glue segment 311 and the first bonding segment 430. The left second upper pressing surface 33 and the left second lower pressing surface 43 cooperate to hot press the second left glue segment 312 and the second negative glue area 420. The left third upper pressing surface 34 and the left third lower pressing surface 44 cooperate to hot press the third left glue segment 313, so that the first glue application area 210 has different hot pressing thicknesses.

[0058] The step surfaces of the first upper step 31, the first lower step 41, the second upper step 61, and the second lower step 71 can be two, three, or even more. The step surfaces of the first hot pressing combination and the second hot pressing assembly 50 can be different. The step height and quantity are flexibly adjusted according to the thickness of the glue application position at the end of the battery cell. Multiple step surfaces can ensure that specific positions in the glue application area at the end of the battery cell can be hot pressed during hot pressing, ensuring the end bonding effect, so as to achieve the purpose of fixing the battery cell electrode tab.

[0059] Specifically, in this embodiment, the first upper step 31 and the first lower step 41 are symmetrically arranged along the horizontal line, and the second upper step 61 and the second lower step 71 are symmetrically arranged along the horizontal line;

[0060] In another embodiment, the first upper step 31 is symmetrically arranged with the second upper step 61 along the center line of the support platform 10, and the first lower step 41 is symmetrically arranged with the second lower step 71 along the center line of the support platform 10. The specific setting method can be adjusted according to different battery cells.

[0061] To ensure the hot pressing effect. The step heights of the first upper step 31, the first lower step 41, the second upper step 61, and the second lower step 71 are adjusted according to the change in the thickness of the glue application areas at both ends of the battery cell. By setting different step heights for glue application areas with different thicknesses, it is ensured that the hot pressing can be in place, ensuring the end bonding effect of the battery cell, so as to achieve the purpose of fixing the battery cell electrode tab.

[0062] To ensure the stability of the hot pressing process, a positioning portion is provided on the support platform 10, and the positioning portion is used to fix the battery cell. There are various ways to set the positioning portion. In one embodiment, the positioning portion can be a relatively arranged protrusion, and the battery cell is located in the protrusion; in another embodiment, the positioning portion can also be in the form of a buckle, a buckle belt, etc. to fix the central area of the battery cell.

[0063] Reference Figures 1 to 3 and Figures 6 to 8 , the present invention also provides a battery cell, including a bare battery cell 200, the bare battery cell 200 includes a negative electrode sheet 400, a separator 500 and a positive electrode sheet 300 which are sequentially stacked, the bare battery cell 200 includes a negative electrode sheet 400, a separator 500 and a positive electrode sheet 300 which are sequentially stacked, the bare battery cell 200 includes a glue application area and a non-glue application area 230, wherein, the glue application area includes a first glue application area 210 provided at one end of the bare battery cell 200, a second glue application area 220 provided at the other end, and the middle part is the non-glue application area 230, the thickness of the glue application area is less than the thickness of the non-glue application area 230, the first glue application area 210 includes a first positive glue area 310 near the tab foil of the positive electrode sheet 300, the second glue application area 220 includes a second positive glue area 320 far from the tab foil of the positive electrode sheet 300 and a first negative glue area 410 near the tab foil of the negative electrode sheet 400; the non-glue application area 230 of the negative electrode sheet 400 includes a first bonding section 430 far from the first negative glue area 410 and a second bonding section 440 near the first negative glue area 410, the first positive glue area 310 includes a first left glue section 311 and a second left glue section 312, the first left glue section 311 corresponds to the first bonding section 430, the second left glue section 312 extends beyond the first bonding section 430, the second positive glue area 320 includes a first right glue section 321 and a second right glue section 322, the first negative glue area 410 includes a first negative glue section 411 and a second negative glue section 412, the first right glue section 321 corresponds to the second bonding section 440, the second right glue section 322 corresponds to the first negative glue section 411, and the second negative glue section 412 extends beyond the second right glue section 322; the first glue application area 210 and the second glue application area 220 are hot pressed by the above-mentioned battery cell hot pressing device 100.

[0064] Specifically, the battery cell is of a wound or laminated structure, and the positive and negative electrode tabs are respectively located at the front end, the rear end of the battery cell or at the same end. The positive electrode tab foil 330 coating area is provided on the positive electrode plate 300 of the battery cell, the front end part of the positive electrode plate 300 is a coating area, and the rear end part of the positive electrode plate 300 is a coating area; the negative electrode plate 400 only has a coating area for the negative electrode tab foil 450. The above positive electrode coating area is hot-pressed by using the above hot-pressing device on the overlapping coating areas of the positive electrode tab foil 330, the coating area at the front end part of the positive electrode plate 300, the coating area at the rear end part of the positive electrode plate 300, and the coating area of the negative electrode tab foil 450 of the negative electrode plate 400, so that the coating area is bonded to the corresponding diaphragm 500 area.

[0065] Further, the first coating area 210 further includes a second negative coating area 420 away from the first negative coating area 410. The first positive coating area 310 further includes a third left coating section 313. The first left coating section 311 corresponds to the first bonding section 430, the second left coating section 312 corresponds to the second negative coating area 420, and the third left coating section 313 extends beyond the second negative coating area 420; the second left coating section 312 includes a positive electrode end coating area of the positive electrode plate 300 part and a positive electrode tab foil coating area of the positive electrode tab foil 330 part.

[0066] Among them, the width of the coating layer of the positive electrode tab foil 330 coating area is the width of the positive electrode tab foil 330, the height is 1 - 10um, and the thickness is 5 - 100um.

[0067] The width of the coating layer of the positive electrode end coating area is the width of the positive electrode plate 300, the height is 1 - 20um, and the thickness is 5 - 100um.

[0068] The width of the coating layer of the first left coating section 311 is the width of the positive electrode plate 300, the height is 1 - 20um, and the thickness is 5 - 100um.

[0069] The width of the coating layer of the first negative coating area 410 is the width of the negative electrode tab foil 450, the height is 1 - 10um, and the thickness is 5 - 100um.

[0070] The width of the coating layer of the second negative coating area 420 is the width of the negative electrode plate 400, the height is 1 - 20um, and the thickness is 5 - 100um.

[0071] In summary, the battery cell hot-pressing device 100 can hot-press at specific positions of the coating area, can hot-press the first coating area 210 and the second coating area 220 with different thickness changes at the end of the bare battery cell 200, ensure the bonding effect of the positive electrode plate 300, the diaphragm 500, and the negative electrode plate 400, and make the hot-pressing thickness of the first coating area 210 decrease in the direction close to the electrode tab foil of the positive electrode plate 300. The hot-pressing thickness of the second coating area 220 decreases in the direction close to the electrode tab foil of the negative electrode plate 400.

[0072] The above are only alternative embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made by using the content of the specification and drawings of the present invention under the inventive concept of the present invention, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A cell hot-pressing device for hot-pressing a bare cell, the bare cell comprising a negative electrode sheet, a separator and a positive electrode sheet stacked in sequence, the bare cell comprising a gluing area and a non-gluing area, wherein, The glue application area includes a first glue application area provided at one end of the bare battery cell, a second glue application area provided at the other end, and a non-glue application area in the middle part. The thickness of the glue application area is less than that of the non-glue application area. It is characterized in that the battery cell hot pressing device includes: A driving device for providing driving force; A supporting platform for placing the battery cell, with both ends of the bare battery cell extending beyond both ends of the supporting platform; A first hot pressing assembly provided at one end of the supporting platform. The first hot pressing assembly includes a first upper hot pressing member and a first lower hot pressing member that are arranged opposite to each other up and down and are connected to the driving device. The first upper hot pressing member includes a first upper pressing member connected to the driving device and a first upper hot pressing portion provided on the first upper pressing member. The first lower hot pressing member includes a first lower pressing member connected to the driving device and a first lower hot pressing portion arranged corresponding to the first upper hot pressing portion. The first upper hot pressing portion and the first lower hot pressing portion cooperate to hot press the first glue application area of the bare battery cell, so that the first glue application area has different hot pressing thicknesses; and A second hot pressing assembly provided at the other end of the supporting platform. The second hot pressing assembly includes a second upper hot pressing member and a second lower hot pressing member that are arranged opposite to each other up and down and are connected to the driving device. The second upper hot pressing member includes a second upper pressing member connected to the driving device and a second upper hot pressing portion provided on the second upper pressing member. The second lower hot pressing member includes a second lower pressing member connected to the driving device and a second lower hot pressing portion arranged corresponding to the second upper hot pressing portion. The second upper hot pressing portion and the second lower hot pressing portion cooperate to hot press the second glue application area of the bare battery cell, so that the second glue application area has different hot pressing thicknesses.

2. The cell hot-pressing device according to claim 1, characterized in that, The first glue application area includes a first positive glue area provided on the positive electrode plate near its tab foil and a first bonding section provided on the negative electrode plate away from its tab foil. The first positive glue area includes a first left glue section and a second left glue section. The first left glue section corresponds to the first bonding section, and the second left glue section extends beyond the first bonding section; The first upper hot pressing portion is formed with a first upper step, and the first lower hot pressing portion is formed with a first lower step that cooperates with the first upper step. The first upper step includes a left first upper pressing surface and a left second upper pressing surface, and the first lower step includes a left first lower pressing surface and a left second lower pressing surface. The left first upper pressing surface and the left first lower pressing surface cooperate to hot press the first left glue section and the first bonding section, and the left second upper pressing surface and the left second lower pressing surface cooperate to hot press the second left glue section, so that the hot pressing thickness of the first glue application area decreases in the direction close to the tab foil of the positive electrode plate.

3. The cell hot-pressing device according to claim 1, characterized in that, characterized in that, The first glue application area includes a first positive glue area provided on the positive electrode plate near its tab foil, a first bonding section provided on the negative electrode plate away from its tab foil, and a second negative glue area provided on the negative electrode plate and located outside the first bonding section. The first positive glue area includes a first left glue section, a second left glue section, and a third left glue section. The first left glue section corresponds to the first bonding section, the second left glue section corresponds to the second negative glue area, and the third left glue section extends beyond the second negative glue area. The thickness of the first bonding section is greater than that of the second negative glue area; The first upper hot pressing part is formed with a first upper step, and a first lower step that cooperates with the first upper step is formed on the first lower hot pressing part. The first upper step includes a left first upper pressing surface, a left second upper pressing surface, and a left third upper pressing surface. The first lower step includes a left first lower pressing surface, a left second lower pressing surface, and a left third lower pressing surface. The left first upper pressing surface and the left first lower pressing surface cooperate to hot press the first left glue segment and the first bonding segment. The left second upper pressing surface and the left second lower pressing surface cooperate to hot press the second left glue segment and the second negative glue area. The left third upper pressing surface and the left third lower pressing surface cooperate to hot press the third left glue segment, so that the thickness of the first glue application area decreases in the direction close to the pole ear foil of the positive electrode sheet during hot pressing.

4. The cell hot-pressing device according to claim 2 or 3, characterized in that, The second glue application area includes a second positive glue area provided on the positive electrode sheet away from its pole ear foil, a first negative glue area provided on the negative electrode sheet close to its pole ear foil, and a second bonding segment provided on the negative electrode sheet and located inside the first negative glue area. The second positive glue area includes a first right glue segment and a second right glue segment. The first negative glue area includes a first negative glue segment and a second negative glue segment. The first right glue segment corresponds to the second bonding segment. The second right glue segment corresponds to the first negative glue segment. The second negative glue segment extends beyond the second right glue segment. The second upper hot pressing part is formed with a second upper step, and a second lower step that cooperates with the second upper step is formed on the second lower hot pressing part. The second upper step includes a right first upper pressing surface, a right second upper pressing surface, and a right third upper pressing surface. The second lower step includes a right first lower pressing surface, a right second lower pressing surface, and a right third lower pressing surface. The right first upper pressing surface and the right first lower pressing surface cooperate to hot press the first right glue segment and the second bonding segment. The right second upper pressing surface and the right second lower pressing surface cooperate to hot press the second right glue segment and the first negative glue segment. The left third upper pressing surface and the left third lower pressing surface cooperate to hot press the second negative glue segment, so that the thickness of the second glue application area decreases in the direction close to the pole ear foil of the negative electrode sheet during hot pressing.

5. The cell hot-pressing device according to claim 4, characterized in that, The first upper step and the first lower step are symmetrically arranged along a horizontal line, and the second upper step and the second lower step are symmetrically arranged along a horizontal line; and / or, the first upper step is symmetrically arranged with the second upper step along the center line of the support platform, and the first lower step is symmetrically arranged with the second lower step along the center line of the support platform.

6. The cell hot-pressing device according to claim 4, characterized in that, The cell hot pressing device includes at least two first hot pressing components and second hot pressing components corresponding to the number of the first hot pressing components. Both the first hot pressing components and the second hot pressing components are detachably connected to the driving device. The heights of the first upper steps and the first lower steps of different first hot pressing components are different. By replacing the first hot pressing components and the corresponding second hot pressing components, a bare cell with different thicknesses of the first glue application area and the second glue application area can be hot pressed; or The cell hot pressing device includes a step pad, and the step pad can be detachably placed on the first upper step, the first lower step, the second upper step, and the second lower step to hot press a bare cell with different thicknesses of the first glue application area and the second glue application area.

7. The cell hot-pressing device according to claim 1, characterized in that, The support platform is provided with a positioning portion for fixing the bare battery cell.

8. A cell, characterized in that, It includes a bare battery cell, which is obtained by hot pressing with the battery cell hot pressing device as described in any one of claims 1 to 7.

9. The cell according to claim 8, characterized in that, The second left glue segment of the positive electrode sheet includes a positive electrode end glue area of the positive electrode sheet part and a positive electrode tab glue area of the positive electrode tab foil part; Among them, the width of the glue coating layer of the positive electrode tab glue area is the width of the positive electrode tab, the height is 1-10 μm, and the thickness is 5-100 μm; The width of the glue coating layer of the positive electrode end glue area is the width of the positive electrode sheet, the height is 1-20 μm, and the thickness is 5-100 μm; The width of the glue coating layer of the first left glue segment of the positive electrode sheet is the width of the positive electrode sheet, the height is 1-20 μm, and the thickness is 5-100 μm; The width of the glue coating layer of the first negative glue area of the negative electrode sheet is the width of the negative electrode tab, the height is 1-10 μm, and the thickness is 5-100 μm; The width of the glue coating layer of the second negative glue area of the negative electrode sheet is the width of the negative electrode sheet, the height is 1-20 μm, and the thickness is 5-100 μm.

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