Flexible contact based full solid state cell anti-bending and anti-wrinkle isostatic pressing mold

Abstract

The utility model provides a kind of full-solid-state electric core anti-bending anti-wrinkle isostatic pressing mould based on flexible contact, including die steel frame, flexible contact pad, flexible edge pad, edge edge-pressing structural member;The upper surface of die steel frame is provided with the die groove matched with the electric core body of electric core, the shape of flexible contact pad is matched with the electric core body of electric core, the shape of flexible edge pad is matched with the package edge of electric core, the shape of edge edge-pressing structural member is matched with the package edge of electric core, and a plurality of connecting holes are correspondingly provided on die steel frame with edge edge-pressing structural member.The utility model adopts flexible edge pad to press the edge aluminum plastic film part of electric core, edge edge-pressing structural member applies uniform plane pressure to electric core edge, after isostatic pressing, aluminum plastic film edge is smooth, and wrinkle is greatly reduced, by using flexible contact pad to contact the surface of electric core, so that electric core is uniformly stressed, effectively solve the edge concave problem in isostatic pressing process, and significantly reduce the bending deformation of electric core.

Description

Technical Field

[0001] This utility model relates to solid-state batteries, specifically to an isostatic pressing mold for all-solid-state cells based on flexible contact, designed to prevent bending and wrinkling. Background Technology

[0002] In the manufacturing process of solid-state batteries, the isostatic pressing process is a key process for the core functional layers of the cell (positive electrode, solid electrolyte, and negative electrode stack). The core objective is to optimize interlayer contact, reduce interfacial impedance, and improve structural density through "uniform pressure action," thereby improving the battery's ion conduction efficiency and cycle stability.

[0003] A Chinese patent with publication number CN111883855B discloses an all-solid-state battery cell, its preparation method, and a solid-state battery. The preparation method includes: 1) bonding a negative electrode sheet to an electrolyte membrane and performing isostatic pressing to obtain a first semi-finished battery cell; 2) bonding a positive electrode sheet to the electrolyte membrane of the first semi-finished battery cell and performing isostatic pressing to obtain the all-solid-state battery cell.

[0004] Currently, all-solid-state battery cells commonly employ aluminum-plastic film encapsulation technology in isostatic pressing processes. However, due to the characteristics of aluminum-plastic film materials or defects in the encapsulation process, the battery cells are susceptible to uneven pressure distribution during isostatic pressing, leading to bending deformation. This problem not only reduces the yield of the finished battery cells but may also affect their electrochemical performance and lifespan.

[0005] Therefore, there is a need to provide an isostatic pressing mold for all-solid-state battery cells based on flexible contact to prevent bending and wrinkling. This mold can solve the problem of torsional bending deformation caused by lateral pressure asymmetry due to aluminum-plastic film encapsulation during isostatic pressing, reduce wrinkling at the edges of the aluminum-plastic film, and reduce bending deformation of the battery cells, thereby improving the yield rate. Utility Model Content

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide an isostatic pressing mold for all-solid-state battery cells that is designed to prevent bending and wrinkling based on flexible contact.

[0007] According to the present invention, a flexible contact-based all-solid-state battery cell anti-bending and anti-wrinkle isostatic pressing mold is provided, comprising: a mold steel frame, a flexible contact pad, a flexible edge pad, and an edge pressing structure. The upper surface of the mold steel frame is provided with a mold groove that matches the body of the battery cell. The upper surface of the mold steel frame is also provided with a mold tab groove that matches the tab of the battery cell. The shape of the flexible contact pad matches the body of the battery cell. The shape of the flexible edge pad matches the encapsulation edge of the battery cell. The flexible edge pad is provided with a tab clearance groove that matches the tab of the battery cell. The shape of the edge pressing structure matches the encapsulation edge of the battery cell. The edge pressing structure and the mold steel frame are provided with multiple connection holes corresponding to each other. The battery cell is placed on the mold steel frame, the flexible contact pad is placed on the battery cell body, the flexible edge pad is placed on the encapsulation edge of the battery cell, the edge pressing structure is placed on the flexible edge pad, and the edge pressing structure is fastened to the mold steel frame through the connecting hole.

[0008] Preferably, the size of the flexible edge pad is not less than the size of the battery cell's encapsulation edge, the inner edge of the flexible edge pad is fitted to the battery cell body, and the outer edge of the flexible edge pad extends to the outside of the battery cell's encapsulation edge.

[0009] Preferably, the inner edge of the edge pressing structure has the same dimensions as the inner edge of the flexible edge pad, and the outer edge of the edge pressing structure has the same dimensions as the outer edge of the mold steel frame.

[0010] Preferably, the connecting holes are evenly distributed on the outer edges of the edge pressing structure and the mold steel frame, and the connecting holes do not contact the flexible edge pad.

[0011] Preferably, the sidewalls of the flexible contact pad are all fitted to the inner sidewalls of the edge pressing structure.

[0012] Preferably, the height of the flexible contact pad placed on the battery cell is not higher than the height of the edge pressing structure, and a pressure-applying structure is provided above the flexible contact pad.

[0013] Preferably, the flexible contact pad includes a silicone contact pad, and the flexible edge pad includes a silicone edge pad.

[0014] Preferably, there is a gap between the sidewall of the mold groove and the battery cell body, and the gap does not exceed 0.5 mm.

[0015] Preferably, a pad or multiple stacked pads are placed at the bottom of the mold groove, and the pads completely cover the bottom of the groove.

[0016] Preferably, the flatness of the inner surface of the mold steel frame is within ±0.05mm.

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention effectively suppresses shrinkage by using flexible edge pads to press the edge aluminum-plastic film of the battery cell. The independent adjustment function of the screws allows the edge pressing structure to apply uniform planar pressure to the edge of the battery cell, offsetting the asymmetric stress during isostatic pressing. After isostatic pressing, the edge of the aluminum-plastic film is flat and wrinkles are greatly reduced. By using flexible contact pads to contact the surface of the battery cell, the battery cell is subjected to uniform force, effectively solving the problem of edge concavity during isostatic pressing, significantly reducing battery cell bending deformation, and greatly improving the yield rate. Attached Figure Description

[0018] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This utility model mainly embodies the structural schematic diagram of an isostatic pressing mold for all-solid-state battery cells based on flexible contact, which is designed to prevent bending and wrinkling.

[0019] Reference numerals: 1. Mold steel frame; 2. Flexible contact pad; 3. Flexible edge pad; 4. Edge pressing structure; 5. Battery cell; 11. Mold groove; 12. Mold tab groove; 31. Tab clearance groove. Detailed Implementation

[0020] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0021] like Figure 1 As shown, the present invention provides an isostatic pressing mold for a fully solid-state battery cell based on flexible contact, which is designed to prevent bending and wrinkling. The mold includes: a mold steel frame 1, a flexible contact pad 2, a flexible edge pad 3, and an edge pressing structure 4. The upper surface of the mold steel frame 1 is provided with a mold groove 11 that matches the battery cell body 5. The upper surface of the mold steel frame 1 is also provided with a mold tab groove 12 that matches the tab of the battery cell 5. The shape of the flexible contact pad 2 matches the battery cell body 5, and the shape of the flexible edge pad 3 matches the packaging edge of the battery cell 5. The flexible edge pad 3 is provided with a tab clearance groove 31 that matches the tab of the battery cell 5. The shape of the edge pressing structure 4 matches the packaging edge of the battery cell 5. The edge pressing structure 4 and the mold steel frame 1 are provided with multiple connection holes respectively. The battery cell 5 is placed on the mold steel frame 1, the flexible contact pad 2 is placed on the battery cell body of the battery cell 5, the flexible edge pad 3 is placed on the packaging edge of the battery cell 5, and the edge pressing structure 4 is placed on the flexible edge pad 3. The edge pressing structure 4 is fastened to the mold steel frame 1 through the connection holes.

[0022] The mold steel frame 1 is made of high-strength mold steel material. The flatness of the inner surface of the mold steel frame 1 is within ±0.05mm to ensure uniform pressure transmission.

[0023] Flexible contact pad 2 includes a silicone contact pad, and flexible edge pad 3 includes a silicone edge pad. Flexible contact pad 2 and flexible edge pad 3 may also be made of other flexible materials.

[0024] The size of the flexible edge pad 3 is not less than the size of the encapsulation edge of the battery cell 5. The inner edge of the flexible edge pad 3 is attached to the battery cell body of the battery cell 5, and the outer edge of the flexible edge pad 3 extends to the outside of the encapsulation edge of the battery cell 5.

[0025] The inner edge of the edge pressing structure 4 is the same size as the inner edge of the flexible edge pad 3, and the outer edge of the edge pressing structure 4 is the same size as the outer edge of the mold steel frame 1.

[0026] The connecting holes are evenly distributed on the outer edges of the edge pressing structure 4 and the mold steel frame 1, and the connecting holes do not contact the flexible edge pad 3.

[0027] The sidewalls of the flexible contact pad 2 are all fitted to the inner sidewall of the edge pressing structure 4.

[0028] The height of the flexible contact pad 2 placed on the battery cell 5 is no higher than the height of the edge pressing structure 4, and a pressure-applying structure is provided above the flexible contact pad 2. The pressure-applying structure and the edge pressing structure 4 are generally made of the same material as the mold steel frame 1.

[0029] There is a gap between the sidewall of the mold groove 11 and the cell body of the cell 5, and the gap does not exceed 0.5mm.

[0030] To improve the adaptability of the mold, one or more stacked shims can be placed at the bottom of the mold groove 11, with the shims completely covering the bottom of the groove.

[0031] The method of using this application includes the following steps: Step 1: Place the battery cell 5 into the mold steel frame 1, place the flexible edge pad 3 on the encapsulation edge of the battery cell 5, place the flexible contact pad 2 on the battery cell body of the battery cell 5, place the edge pressing structure 4 on the flexible edge pad 3, place the pressure structure on the flexible contact pad 2, and connect the edge pressing structure 4 to the mold steel frame 1 with screws. Step 2: Use a torque wrench to tighten each screw to 5 N·m, while ensuring that the same force is applied to each screw; Step 3: Place the mold into the isostatic press and apply a pressure of 300 MPa; Step 4: Remove the mold, loosen the screws one by one, and remove the battery cell 5.

[0032] This application is further illustrated by the following embodiments.

[0033] In traditional processes, for battery cells with dimensions of 53mm x 108mm x 1mm (length x width x thickness), isostatic pressing is performed directly without using the mold described in this application. This results in severe torsional bending of the battery cell, with a height difference of over 10mm between the two surfaces. Alternatively, for battery cells with dimensions of 53mm x 108mm x 1mm (length x width x thickness), isostatic pressing using rigid contact fixtures results in noticeable wrinkles at the cell edges and slight inward concavity along the four sides.

[0034] In this application, the specifications of cell 5 are 53mm x 108mm x 1mm (length x width x thickness). Using the mold of this application for isostatic pressing, the bending degree of cell 5 is reduced from 10mm in the traditional process to within 0.01mm, increasing the yield to over 99%. The specifications of cell 5 are also 53mm x 108mm x 5mm (length x width x thickness). Using the mold of this application for isostatic pressing, for thicker cells 5, the bending degree of cell 5 is stabilized within 0.01mm from 2mm in the traditional process, increasing the yield to over 99%.

[0035] In traditional processes, a simple two-plate pressure design can prevent the battery cell from bending. However, uneven stress on the battery cell can cause the edges to dent inwards. Therefore, this application uses a silicone pad on the contact surface with the battery cell; simultaneously, a silicone strip is used at the edge of the aluminum-plastic film.

[0036] This application effectively suppresses shrinkage and prevents wrinkles at the edges of the aluminum-plastic film of the battery cell 5 by using a flexible edge pad 3 to press the film firmly. After isostatic pressing, the edges of the aluminum-plastic film of the battery cell 5 are smooth, and wrinkles are significantly reduced. The flexible contact pad 2 effectively prevents uneven stress on the battery cell caused by rigid pressure, thus preventing edge deformation. By ensuring uniform stress on the battery cell 5, the problem of edge concavity during isostatic pressing is effectively solved, significantly reducing bending deformation and greatly improving yield. The independent adjustment function of the screws allows the edge pressing structure 4 to apply uniform planar pressure to the battery cell edge, counteracting asymmetric stress during isostatic pressing.

[0037] This application has a simple structure, can be adapted to battery cells 5 of different thicknesses, can apply pressure evenly, can improve the structural integrity of battery cells 5, and improve the yield rate.

[0038] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0039] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the substantive content of this utility model. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A flexible contact-based all-solid-state cell anti-bending and anti-wrinkle isostatic pressing mold, characterized in that, include: Mold steel frame (1), flexible contact pad (2), flexible edge pad (3), edge pressing structure (4); The upper surface of the mold steel frame (1) is provided with a mold groove (11) that matches the body of the battery cell (5). The upper surface of the mold steel frame (1) is also provided with a mold tab groove (12) that matches the tab of the battery cell (5). The shape of the flexible contact pad (2) matches the body of the battery cell (5). The shape of the flexible edge pad (3) matches the encapsulation edge of the battery cell (5). The flexible edge pad (3) is provided with a tab clearance groove (31) that matches the tab of the battery cell (5). The shape of the edge pressing structure (4) matches the encapsulation edge of the battery cell (5). The edge pressing structure (4) and the mold steel frame (1) are provided with multiple connection holes respectively. The battery cell (5) is placed on the mold steel frame (1), the flexible contact pad (2) is placed on the battery cell body of the battery cell (5), the flexible edge pad (3) is placed on the encapsulation edge of the battery cell (5), the edge pressing structure (4) is placed on the flexible edge pad (3), and the edge pressing structure (4) is fastened to the mold steel frame (1) through the connecting hole.

2. The isostatic pressing mold for all-solid-state battery cells based on flexible contact for preventing bending and wrinkling as described in claim 1, characterized in that, The size of the flexible edge pad (3) is not less than the size of the encapsulation edge of the cell (5). The inner edge of the flexible edge pad (3) is attached to the cell body of the cell (5). The outer edge of the flexible edge pad (3) extends to the outside of the encapsulation edge of the cell (5).

3. The isostatic pressing mold for all-solid-state battery cells based on flexible contact for preventing bending and wrinkling as described in claim 1, characterized in that, The inner edge of the edge pressing structure (4) is the same size as the inner edge of the flexible edge pad (3), and the outer edge of the edge pressing structure (4) is the same size as the outer edge of the mold steel frame (1).

4. The isostatic pressing mold for all-solid-state battery cells based on flexible contact for preventing bending and wrinkling as described in claim 1, characterized in that, The connecting holes are evenly distributed on the outer edges of the edge pressing structure (4) and the mold steel frame (1), and the connecting holes do not contact the flexible edge pad (3).

5. The isostatic pressing mold for all-solid-state battery cells based on flexible contact for preventing bending and wrinkling as described in claim 1, characterized in that, The sidewalls of the flexible contact pad (2) are all fitted to the inner sidewalls of the edge pressing structure (4).

6. The isostatic pressing mold for all-solid-state battery cells based on flexible contact for preventing bending and wrinkling as described in claim 1, characterized in that, The height of the flexible contact pad (2) placed on the battery cell (5) is not higher than the height of the edge pressing structure (4), and a pressure structure is provided above the flexible contact pad (2).

7. The isostatic pressing mold for all-solid-state battery cells based on flexible contact for preventing bending and wrinkling as described in claim 1, characterized in that, The flexible contact pad (2) includes a silicone contact pad, and the flexible edge pad (3) includes a silicone edge pad.

8. The isostatic pressing mold for all-solid-state battery cells based on flexible contact for preventing bending and wrinkling as described in claim 1, characterized in that, There is a gap between the sidewall of the mold groove (11) and the battery cell body of the battery cell (5), and the gap does not exceed 0.5 mm.

9. The isostatic pressing mold for all-solid-state battery cells based on flexible contact for preventing bending and wrinkling as described in claim 1, characterized in that, A pad or multiple stacked pads are placed at the bottom of the mold groove (11), and the pads completely cover the bottom of the groove.

10. The isostatic pressing mold for all-solid-state battery cells based on flexible contact for preventing bending and wrinkling as described in claim 1, characterized in that, The flatness of the inner surface of the mold steel frame (1) is within ±0.05mm.

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