Hot pressing mechanism

Abstract

The hot-pressing mechanism comprises two hot-pressing assemblies oppositely arranged in the first direction, and a hot-pressing space suitable for containing a battery cell to be subjected to hot-pressing is formed between the two hot-pressing assemblies; the hot-pressing assembly comprises a hot-pressing plate, an elastic heat-conducting base plate and an elastic structure arranged between the hot-pressing plate and the elastic heat-conducting base plate, and the elastic structure is connected with the hot-pressing plate and the elastic heat-conducting base plate. The elastic heat-conducting base plate is arranged close to the hot-pressing space and is used for abutting against the to-be-hot-pressed battery cell. Therefore, under the elastic action of the elastic structure, the elastic heat-conducting base plate can adaptively deform so as to be attached to the to-be-hot-pressed battery cell. In other words, in the hot pressing process, the elastic heat conduction base plate can be tightly attached to the whole to-be-hot-pressed battery cell, so that the surface of the to-be-hot-pressed battery cell is subjected to uniform hot pressure, and the overall yield of the battery cell is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of battery hot pressing, and specifically relates to a hot pressing mechanism. Background Art

[0002] The hot pressing process is an important step in the manufacture of battery cells. The electrode coated with the diaphragm glue layer is preheated and then placed between two hot pressing plates of a hot pressing mechanism for hot pressing, so that the diaphragm glue layer and the electrode are thermally polymerized and bonded to form a battery cell with a higher overall hardness.

[0003] However, the hot pressing plate of the existing hot pressing mechanism is usually a flat plate, and the battery cell includes a main body area and a thinned area, wherein the thickness of the thinned area is less than that of the main body area. This will cause a gap between the hot pressing plate and the thinned area during the hot pressing process, making it difficult for the thermal pressure to be transmitted to the thinned area, resulting in poor thermal polymerization and bonding between the diaphragm adhesive layer and the pole piece in the thinned area, resulting in a decrease in the overall yield rate of the battery cell. Utility Model Content

[0004] The present application aims to provide a hot pressing mechanism to solve the problem that there is a gap between the hot pressing plate and the thinning area of ​​the existing hot pressing mechanism, which makes it difficult to transfer the thermal pressure to the thinning area, resulting in a low overall yield rate of the battery cell.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] In a first aspect, the present application discloses a hot pressing mechanism, which is applied to a battery cell to be hot pressed, and the hot pressing mechanism comprises: two hot pressing assemblies arranged opposite to each other along a first direction, and a hot pressing space suitable for accommodating the battery cell to be hot pressed is provided between the two hot pressing assemblies;

[0007] The hot pressing assembly includes a hot pressing plate, an elastic heat-conducting pad, and an elastic structure arranged between the hot pressing plate and the elastic heat-conducting pad, wherein the elastic structure is connected to the hot pressing plate and the elastic heat-conducting pad respectively;

[0008] The elastic heat-conducting pad is arranged close to the hot pressing space, and the elastic heat-conducting pad is used to abut against the battery core to be hot pressed.

[0009] Optionally, the battery core to be hot pressed comprises a body region and a thinned region, and the thickness of the thinned region is smaller than the thickness of the body region;

[0010] The elastic thermally conductive pad includes a first hot pressing area and a second hot pressing area, wherein the first hot pressing area is used to abut against the body area, and the second hot pressing area is used to abut against the thinning area;

[0011] The elastic structure is arranged between the hot pressing plate and the second hot pressing zone, so that the second hot pressing zone is deformed to fit the thinning zone.

[0012] Optionally, the length direction of the elastic thermally conductive pad is a second direction, and the second direction is perpendicular to the first direction;

[0013] There are two second hot pressing zones, and the two second hot pressing zones are respectively located on both sides of the first hot pressing zone along the second direction;

[0014] The elastic structure is provided in two groups, and one group of the elastic structure is provided between one of the second hot pressing zones and the hot pressing plate.

[0015] Optionally, the elastic thermally conductive pad is detachably connected to the heat pressing plate.

[0016] Optionally, the elastic thermally conductive pad is threadedly connected to the hot pressing plate.

[0017] Optionally, a threaded sleeve is provided on one side of the first hot pressing zone close to the hot pressing plate;

[0018] The hot pressing assembly further includes a bolt, which is arranged to penetrate the hot pressing plate along the first direction and is threadedly connected to the threaded sleeve.

[0019] Optionally, the length direction of the elastic thermally conductive pad is the second direction, the width direction of the elastic thermally conductive pad is the third direction, and the first direction, the second direction, and the third direction are perpendicular to each other;

[0020] The threaded sleeves are provided in plurality, and the plurality of threaded sleeves are distributed in an array along the second direction and the third direction;

[0021] A plurality of the bolts are provided, and one of the bolts is cooperatively connected with one of the threaded sleeves.

[0022] Optionally, the heat pressing plate has a first thermal conductivity, the elastic thermal conductive pad has a second thermal conductivity, and the second thermal conductivity is greater than the first thermal conductivity.

[0023] Optionally, the elastic structure includes a first elastic member that is retractable along the first direction, and the first elastic member is used to drive the elastic thermal conductive pad to deform so as to fit the battery core to be hot pressed.

[0024] Optionally, the first elastic member is a disc spring.

[0025] Optionally, the first elastic member is a coil spring.

[0026] Optionally, the first elastic member is a leaf spring.

[0027] Optionally, the hot pressing plate is provided with a guide hole, and the guide hole is extended along the first direction;

[0028] The elastic structure further comprises a guide assembly, the guide assembly is slidably connected to the guide hole along the first direction, and at least a portion of the guide assembly abuts against the elastic thermal conductive pad;

[0029] The first elastic member is sleeved on the guide assembly. Under the expansion and contraction action of the first elastic member, the guide assembly slides along the first direction to deform the elastic thermal conductive pad.

[0030] Optionally, the guide assembly comprises: a guide post, a first stopper and a second stopper;

[0031] The guide post is slidably connected to the guide hole;

[0032] The first elastic member is sleeved on the guide column, and under the expansion and contraction action of the first elastic member, the guide column slides along the first direction;

[0033] The first limit member and the second limit member are respectively arranged at the two ends of the guide column along the first direction, and the second limit member is close to the elastic thermal conductive pad and abuts against the elastic thermal conductive pad; the first limit member and the second limit member are used to limit the sliding of the guide column to limit the deformation degree of the elastic thermal conductive pad.

[0034] Optionally, the guide hole comprises: a first guide hole and a second guide hole arranged along the first direction and connected to each other, the first guide hole and the second guide hole are coaxially arranged, and the second guide hole is close to the elastic thermal conductive pad;

[0035] The inner diameter of the second guide hole is larger than the inner diameter of the first guide hole, and at least part of the second limiting member is engaged with the second guide hole to limit the position of the second limiting member;

[0036] A limiting flange is further provided at one end of the first guide hole away from the second guide hole, and the limiting flange is used to abut against the first limiting member to limit the first limiting member.

[0037] In the embodiment of the present application, the hot pressing mechanism includes: two hot pressing components arranged opposite to each other along the first direction, and there is a hot pressing space between the two hot pressing components suitable for accommodating the battery cell to be hot pressed; the hot pressing component includes a hot pressing plate, an elastic heat conductive pad, and an elastic structure arranged between the hot pressing plate and the elastic heat conductive pad, the elastic heat conductive pad is close to the hot pressing space, and the elastic heat conductive pad is elastically connected to the hot pressing plate through the elastic structure. In this way, since the elastic heat conductive pad and the elastic structure are provided, under the elastic action of the elastic structure, the elastic heat conductive pad can be adaptively deformed to fit the battery cell to be hot pressed. That is, during the hot pressing process, the elastic heat conductive pad can be tightly fitted with the battery cell to be hot pressed as a whole, so that the surface of the battery cell to be hot pressed is subjected to uniform heat pressure, which can effectively avoid the problem that the heat pressure is difficult to be transmitted to the thinning area, thereby improving the thermal polymerization bonding effect of the diaphragm glue layer in the thinning area and the battery cell to be hot pressed, which is conducive to improving the overall yield rate of the battery cell.

[0038] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0040] Figure 1 It is a schematic diagram of the structure of a cell to be hot pressed in the prior art;

[0041] Figure 2 This is one of the structural schematic diagrams of a hot pressing mechanism provided in an embodiment of the present application;

[0042] Figure 3 This is the second structural schematic diagram of a hot pressing mechanism provided in an embodiment of the present application;

[0043] Figure 4 This is the third structural schematic diagram of a hot pressing mechanism provided in an embodiment of the present application;

[0044] Figure 5 is a schematic diagram of the structure of the elastic thermally conductive pad provided in an embodiment of the present application;

[0045] Figure 6 yes Figure 3 A partial enlarged view of the middle A;

[0046] Figure 7 yes Figure 4 A partial enlarged view of point B in the middle.

[0047] Figure markings: 1. Battery cell to be hot pressed, 11. Main body area, 12. Thinning area, 2. Hot pressing plate, 21. Guide hole, 211. First guide hole, 2111. Limiting flange, 212. Second guide hole, 22. Mounting groove, 3. Elastic thermal conductive pad, 31. First hot pressing zone, 311. Threaded sleeve, 32. Second hot pressing zone, 4. Elastic structure, 41. First elastic part, 42. Guide assembly, 421. Guide column, 422. First limiting part, 423. Second limiting part, 5. Elastic support assembly, 51. Support column, 52. Second elastic part, 6. Heating element, X. First direction, Y. Second direction, Z. Third direction. DETAILED DESCRIPTION

[0048] The embodiments of the utility model will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the utility model, and cannot be understood as limiting the utility model. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0049] The term "first" or "second" in the specification and claims of this application may include one or more of the features explicitly or implicitly. In the description of this utility model, unless otherwise specified, "multiple" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0050] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0051] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] Reference Figure 1 , shows a schematic diagram of the structure of a hot pressed cell in the prior art. During the manufacturing process of the pole piece, due to the characteristics of the slurry, the thickness of the coated pole piece near the pole ear is less than the thickness of other positions of the pole piece, wherein the pole ear refers to the metal conductor leading out of the pole piece. In this way, the hot pressed cell 1 formed by alternating stacking of multiple pole pieces and diaphragm glue layers will have a body area 11 and a thinning area 12, wherein the thickness of the thinning area 12 is less than the thickness of the body area 11, as shown in FIG. Figure 1 As shown. Since the hot pressing plate 2 is usually a flat plate, during the hot pressing process, the hot pressing plate 2 first contacts the body area 11 of the battery cell 1 to be hot pressed. At the same time, there is a gap between the hot pressing plate 2 and the thinning area 12 of the battery cell 1 to be hot pressed, which makes it difficult for the thermal pressure to be transmitted to the thinning area 12, resulting in poor thermal polymerization bonding effect between the diaphragm glue layer and the pole piece in the thinning area 12, resulting in a decrease in the overall yield rate of the battery cell.

[0053] An embodiment of the present application provides a hot pressing mechanism, which will be described in detail below in conjunction with the accompanying drawings.

[0054] Reference Figures 2 to 4 , showing a schematic diagram of the structure of a hot pressing mechanism provided in an embodiment of the present application, referring to Figure 5 , showing a schematic diagram of the structure of the elastic thermal conductive pad provided in the embodiment of the present application, referring to Figure 6 , showing Figure 3 The enlarged view of the part at A in the middle, refer to Figure 7 , showing Figure 4 A partial enlarged view of point B in the middle.

[0055] like Figures 2 to 4 As shown, the present application provides a hot pressing mechanism, which is applied to a battery cell 1 to be hot pressed, and the hot pressing mechanism includes: two hot pressing components arranged relatively to each other along a first direction X, and a hot pressing space suitable for accommodating the battery cell 1 to be hot pressed is provided between the two hot pressing components; the hot pressing component includes a hot pressing plate 2, an elastic thermal conductive pad 3, and an elastic structure 4 arranged between the hot pressing plate 2 and the elastic thermal conductive pad 3, and the elastic structure 4 is respectively connected to the hot pressing plate 2 and the elastic thermal conductive pad 3; the elastic thermal conductive pad 3 is arranged close to the hot pressing space, and the elastic thermal conductive pad 3 is used to abut against the battery cell 1 to be hot pressed.

[0056] In the embodiment of the present application, since the elastic thermally conductive pad 3 and the elastic structure 4 are provided, the elastic thermally conductive pad 3 can be deformed adaptively to fit the battery core 1 to be hot pressed under the elastic effect of the elastic structure 4. That is, during the hot pressing process, the elastic thermally conductive pad 3 can fit tightly with the battery core 1 to be hot pressed as a whole, so that the surface of the battery core 1 to be hot pressed is subjected to uniform thermal pressure, which can effectively avoid the problem that the thermal pressure is difficult to be transmitted to the thinning area 12, thereby improving the thermal polymerization bonding effect between the diaphragm adhesive layer in the thinning area 12 and the battery core 1 to be hot pressed, which is conducive to improving the overall yield rate of the battery core.

[0057] It should be noted that, taking the elastic thermally conductive pad 3 as an example, the first direction X of the embodiment of the present application refers to the thickness direction of the elastic thermally conductive pad 3, the second direction Y refers to the length direction of the elastic thermally conductive pad 3, and the third direction Z refers to the width direction of the elastic thermally conductive pad 3, and the first direction X, the second direction Y, and the third direction Z are perpendicular to each other. In addition, the elastic thermally conductive pad 3 refers to a plate-like structure that can be deformed and has a heat-conducting function. In addition, except for the side where the elastic thermally conductive pad 3 is located, other positions of the hot pressing assembly are provided with a heat insulation layer, which can not only improve the safety of the use of the hot pressing assembly, but also effectively prevent the heat dissipation of the hot pressing assembly. Among them, the heat insulation layer is usually made of resin material.

[0058] like Figure 5 As shown, the battery cell 1 to be hot pressed includes a main body area 11 and a thinning area 12, and the thickness of the thinning area 12 is less than that of the main body area 11; the elastic thermal conductive pad 3 includes a first hot pressing area 31 and a second hot pressing area 32, the first hot pressing area 31 is used to abut against the main body area 11, and the second hot pressing area 32 is used to abut against the thinning area 12; the elastic structure 4 is arranged between the hot pressing plate 2 and the second hot pressing area 32, so that the second hot pressing area 32 is deformed to fit the thinning area 12.

[0059] In the embodiment of the present application, since the elastic thermally conductive pad 3 includes a first hot pressing zone 31 and a second hot pressing zone 32, wherein the first hot pressing zone 31 is used to abut against the body zone 11 of the battery cell 1 to be hot pressed, and the second hot pressing zone 32 is used to abut against the thinning zone 12 of the battery cell 1 to be hot pressed. In this way, during the hot pressing process, the elastic thermally conductive pad 3 can be tightly fitted with the battery cell 1 to be hot pressed as a whole through the abutment of the first hot pressing zone 31 with the body zone 11 and the abutment of the second hot pressing zone 32 with the thinning zone 12, so that the surface of the battery cell 1 to be hot pressed is subjected to uniform thermal pressure. In addition, since the elastic structure 4 is arranged between the hot pressing plate 2 and the second hot pressing zone 32, under the elastic action of the elastic structure 4, the second hot pressing zone 32 can be adaptively deformed to fit the thinning zone 12, so that the thinning zone 12 is subjected to sufficient thermal pressure, thereby improving the thermal polymerization bonding reliability of the diaphragm glue layer and the pole piece in the thinning zone 12, which is conducive to improving the overall yield rate of the battery cell.

[0060] In some optional embodiments of the present application, two second hot pressing zones 32 are provided, and the two second hot pressing zones 32 are respectively located on both sides of the first hot pressing zone 31 along the second direction Y; two groups of elastic structures 4 are provided, and one group of elastic structures 4 is arranged between a second hot pressing zone 32 and the hot pressing plate 2.

[0061] In practical applications, along the length direction of the battery core 1 to be hot pressed, the battery core 1 to be hot pressed generally includes a main body area 11 and two thinning areas 12 located on both sides of the main body area 11. During the hot pressing process, when the battery core 1 to be hot pressed is placed in the hot pressing space, the length direction of the battery core 1 to be hot pressed is generally consistent with the second direction Y. Based on this, two second hot pressing areas 32 are provided in the embodiment of the present application, and the two second hot pressing areas 32 are respectively located on both sides of the first hot pressing area 31 along the second direction Y. In this way, through the one-to-one corresponding abutment between the two second hot pressing areas 32 and the two thinning areas 12, the elastic thermal conductive pad 3 can be tightly fitted with the battery core 1 to be hot pressed as a whole, so that the surface of the battery core 1 to be hot pressed is subjected to uniform thermal pressure. In addition, since two groups of elastic structures 4 are provided, one group of elastic structures 4 is provided between a second hot pressing area 32 and the hot pressing plate 2. In this way, under the elastic action of the corresponding elastic structure 4, the two second hot pressing areas 32 can adaptively deform respectively to fit the two thinning areas 12 on both sides of the battery cell 1 to be hot pressed, so that the two thinning areas 12 are subjected to sufficient thermal pressure, thereby improving the thermal polymerization bonding reliability of the diaphragm glue layer and the electrode of the two thinning areas 12, which is beneficial to improving the overall yield of the battery cell.

[0062] It should be noted that each group of elastic structures 4 may include one elastic structure 4 or multiple elastic structures 4. The specific number and specific position of each group of elastic structures 4 are not limited in the embodiment of the present application, and those skilled in the art may adjust as needed. It is understandable that in order to further improve the force uniformity of the thinning zone 12, when one elastic structure 4 is provided, one elastic structure 4 is located in the middle area of ​​the projection range of the second hot pressing zone 32 along the third direction Z; when multiple elastic structures 4 are provided, multiple elastic structures 4 are located in the projection range of the second hot pressing zone 32 along the third direction Z, and are evenly distributed within the projection range.

[0063] In some optional embodiments of the present application, the elastic heat-conducting pad 3 is detachably connected to the heat-pressing plate 2. In this way, the elastic heat-conducting pad 3 can be easily repaired and replaced, which is conducive to reducing the use cost of the heat-pressing mechanism.

[0064] It should be noted that the detachable connection method between the elastic thermal conductive pad 3 and the hot pressing plate 2 in the embodiment of the present application includes but is not limited to threaded connection, snap connection, clamping connection or other connection methods, which are not limited here and technical personnel in this field can choose according to needs.

[0065] In some optional embodiments of the present application, the elastic thermally conductive pad 3 is threadedly connected to the hot pressing plate 2 .

[0066] Specifically, a threaded sleeve 311 is provided on one side of the first hot pressing zone 31 close to the hot pressing plate 2 ; the hot pressing assembly further includes a bolt, which is provided along the first direction X and passes through the hot pressing plate 2 and is threadedly connected with the threaded sleeve 311 .

[0067] In the embodiment of the present application, since the first hot pressing zone 31 is provided with a threaded sleeve 311, the bolt passes through the hot pressing plate 2 and is threadedly connected to the threaded sleeve 311. In this way, the elastic heat conductive pad 3 can be reliably connected to the hot pressing plate 2.

[0068] In practical applications, there are multiple threaded sleeves 311, which are distributed in an array along the second direction Y and the third direction Z; there are multiple bolts, and one bolt is connected with one threaded sleeve 311. In this way, on the one hand, the connection reliability between the elastic thermal conductive pad 3 and the hot pressing plate 2 can be further improved; on the other hand, the first hot pressing zone 31 can be closely fitted with the hot pressing plate 2, so that the first hot pressing zone 31 has sufficient rigidity to reliably transfer the thermal pressure of the hot pressing plate 2 to the surface of the battery cell 1 to be hot pressed. Figure 5 As shown, in one of the embodiments, sixteen threaded sleeves 311 are welded on one side of the elastic thermally conductive pad 3 close to the hot pressing plate 2 through a cold welding process, and the sixteen threaded sleeves 311 are distributed in four rows and four columns along the second direction Y and the third direction Z; correspondingly, sixteen bolts are provided, and the sixteen bolts all penetrate the hot pressing plate 2, and are threadedly connected to the threaded sleeves 311 in a one-to-one correspondence, so that the elastic thermally conductive pad 3 and the hot pressing plate 2 are reliably connected together.

[0069] In some optional embodiments of the present application, the hot pressing plate 2 has a first thermal conductivity, the elastic thermal conductive pad 3 has a second thermal conductivity, and the second thermal conductivity is greater than the first thermal conductivity.

[0070] In practical applications, such as Figure 2As shown, the hot pressing plate 2 usually adopts a steel plate with a certain thickness, and the hot pressing plate 2 is provided with a heating element 6. After the heating element 6 heats the hot pressing plate 2, the hot pressing plate 2 transfers the heat to the battery core 1 to be hot pressed. However, due to the large overall temperature difference of the hot pressing plate 2, that is, the temperature of the area close to the heating element 6 is higher, and the temperature of the area far away from the heating element 6 is lower, this will cause the heat transferred to the surface of the battery core 1 to be hot pressed during the hot pressing process to be uneven, affecting the bonding reliability of the diaphragm glue layer and the pole piece. Based on this, the second thermal conductivity of the elastic thermal conductive pad 3 used in the embodiment of the present application is greater than the first thermal conductivity of the hot pressing plate 2, that is, during the heat conduction process, the overall temperature difference of the elastic thermal conductive pad 3 is less than the overall temperature difference of the hot pressing plate 2. In this way, since an elastic thermal conductive pad 3 with better thermal conductivity is provided, the heat conduction between the elastic thermal conductive pad 3 and the surface of the battery core 1 to be hot pressed is smoother, so that the heat transferred to the surface of the battery core 1 to be hot pressed is as uniform as possible.

[0071] It should be noted that the material of the elastic thermally conductive pad 3 in the embodiment of the present application includes but is not limited to beryllium copper material, and those skilled in the art can select it according to actual needs. In one embodiment, the elastic thermally conductive pad 3 is made of beryllium copper, and the thermal conductivity of beryllium copper is higher than that of steel. After testing, the temperature difference between the elastic thermally conductive pad 3 made of beryllium copper and the surface of the hot pressed electric core 1 is small and can reach ±3°.

[0072] like Figure 6 As shown, the elastic structure 4 includes a first elastic member 41 that can be stretched and retracted along a first direction X. The first elastic member 41 is used to drive the elastic thermal conductive pad 3 to deform so as to fit the battery core 1 to be hot pressed.

[0073] In the embodiment of the present application, since the first elastic member 41 is provided, the first elastic member 41 can be stretched and retracted along the first direction X, thereby driving the elastic thermal conductive pad 3 to deform to fit the battery cell 1 to be hot pressed. In this way, the thinned area 12 of the battery cell 1 to be hot pressed can be subjected to sufficient thermal pressure, thereby improving the thermal polymerization bonding reliability of the diaphragm adhesive layer and the pole piece in the thinned area 12, which is conducive to improving the overall yield rate of the battery cell.

[0074] It should be noted that the first elastic member 41 of the embodiment of the present application can be a disc spring, a coil spring, a leaf spring or other types of springs, which are not limited here. Those skilled in the art can select the appropriate type of spring according to actual needs. It can be understood that the thickness difference between the thinning area 12 and the main area 11 of the hot pressed battery 1 is usually small, generally in the micrometer or millimeter level. Therefore, when a disc spring is selected, the disc spring has the characteristics of short stroke, small deformation and large load-bearing capacity, which can reliably drive the elastic thermal conductive pad 3 to deform slightly to compensate for the slight thickness difference of the thinning area 12. In this way, on the one hand, it can avoid overpressure or insufficient pressure of the hot pressed battery 1, which is beneficial to improve the overall yield rate of the battery; on the other hand, it can avoid the problem of large slippage of the elastic thermal conductive pad 3 relative to the hot pressed battery 1 when the deformation of the elastic thermal conductive pad 3 is large, causing the surface of the hot pressed battery 1 to be bruised, which is beneficial to improve the hot pressing stability of the hot pressing process.

[0075] In some optional embodiments of the present application, the hot pressing plate 2 is provided with a guide hole 21, which is extended along the first direction X; the elastic structure 4 also includes a guide component 42, which is slidably connected to the guide hole 21 along the first direction X, and at least a portion of the guide component 42 abuts against the elastic thermal conductive pad 3; the first elastic member 41 is sleeved on the guide component 42, and under the expansion and contraction action of the first elastic member 41, the guide component 42 slides along the first direction X to deform the elastic thermal conductive pad 3.

[0076] In the embodiment of the present application, since the guide hole 21 and the guide assembly 42 are provided, the guide assembly 42 is slidably connected to the guide hole 21 along the first direction X, and the first elastic member 41 is sleeved on the guide assembly 42. In this way, under the expansion and contraction action of the first elastic member 41, the guide assembly 42 slides along the first direction X to deform the elastic thermal conductive pad 3, so as to adapt to the battery cell 1 to be hot-pressed with different thickness differences between the body area 11 and the thinning area 12, which is conducive to improving the versatility of the hot pressing mechanism.

[0077] In some optional embodiments of the present application, the guide assembly 42 includes: a guide column 421, a first limit member 422 and a second limit member 423; the guide column 421 is slidably connected to the guide hole 21; the first elastic member 41 is sleeved on the guide column 421, and under the expansion and contraction action of the first elastic member 41, the guide column 421 slides along the first direction X; the first limit member 422 and the second limit member 423 are respectively arranged at the two ends of the guide column 421 along the first direction X, and the second limit member 423 is close to the elastic thermal conductive pad 3 and abuts against the elastic thermal conductive pad 3; the first limit member 422 and the second limit member 423 are used to limit the sliding of the guide column 421 to limit the deformation degree of the elastic thermal conductive pad 3.

[0078] In the embodiment of the present application, since the guide column 421, the first stopper 422 and the second stopper 423 are provided, and the first stopper 422 and the second stopper 423 are respectively provided at the two ends of the guide column 421, wherein the second stopper 423 abuts against the elastic thermal conductive pad 3. In this way, by providing the first stopper 422 and the second stopper 423 at the two ends of the guide column 421, the sliding stroke of the guide column 421 can be limited, effectively preventing the force of the second stopper 423 acting on the elastic thermal conductive pad 3 from being too small or too large, thereby avoiding the problem of overpressure or underpressure of the hot pressed battery cell 1.

[0079] It should be noted that if Figure 6 As shown, in one embodiment, the first stopper 422 includes a double nut, which is threadedly connected to the guide column 421. By adjusting the position of the double nut relative to the guide column 421, the first elastic member 41 can have an appropriate pre-tightening force. In addition, the second stopper 423 also includes a gasket, which is arranged on the side of the double nut close to the first elastic member 41, so as to increase the contact area between the double nut and the surface of the hot pressing plate 2, and prevent the hot pressing plate 2 from being worn.

[0080] In some optional embodiments of the present application, the guide hole 21 includes: a first guide hole 211 and a second guide hole 212 arranged along a first direction X and connected to each other, the first guide hole 211 and the second guide hole 212 are coaxially arranged, and the second guide hole 212 is close to the elastic thermal conductive pad 3; the inner diameter of the second guide hole 212 is larger than the inner diameter of the first guide hole 211, and at least part of the second limiting member 423 is embedded in the second guide hole 212 to limit the second limiting member 423; a limiting flange 2111 is also provided at the end of the first guide hole 211 away from the second guide hole 212, and the limiting flange 2111 is used to abut against the first limiting member 422 to limit the first limiting member 422.

[0081] In the embodiment of the present application, on the one hand, since the first guide hole 211 and the second guide hole 212 are provided, the inner diameter of the second guide hole 212 is larger than that of the first guide hole 211, so that a step surface can be formed. When the second limiter 423 is engaged with the second guide member, that is, when the second limiter 423 is in contact with the step surface, the second limiter 423 can be limited. On the other hand, since a limit flange 2111 is provided at one end of the first guide hole 211 away from the second guide hole 212, when the limit flange 2111 is in contact with the first limiter 422, the first limiter 422 can be limited. In summary, since the second guide hole 212 and the limit flange 2111 are provided, the second limiter 423 and the first limiter 422 can be limited respectively, thereby limiting the sliding stroke of the guide column 421 along the first direction X, effectively avoiding the problem of overpressure or underpressure of the hot pressing battery core 1.

[0082] like Figure 7 As shown, a mounting groove 22 is provided on one side of the hot pressing plate 2 close to the elastic thermally conductive pad 3; the hot pressing assembly also includes an elastic support assembly 5, which is elastically connected to the mounting groove 22, and is used to support the battery cell 1 to be hot pressed; the elastic support assembly 5 has an extended state and a retracted state, in which the elastic thermally conductive pad 3 and the battery cell 1 to be hot pressed are spaced apart; in the retracted state, the elastic thermally conductive pad 3 abuts against the battery cell 1 to be hot pressed so as to perform hot pressing on the battery cell 1.

[0083] Specifically, the elastic support assembly 5 includes a support column 51 and a second elastic member 52; the support column 51 is slidably connected to the mounting groove 22; the second elastic member 52 is arranged between the mounting groove 22 and the support column 51, and under the elastic action of the second elastic member 52, the support column 51 extends relative to the mounting groove 22, or retracts into the mounting groove 22. The second elastic member 52 is a spring.

[0084] In the embodiment of the present application, since an elastic support assembly 5 is provided, the elastic support assembly 5 has an extended state and a retracted state, which can facilitate the loading and unloading of the battery cell 1 to be hot pressed during the hot pressing process. Specifically, in the extended state, the support column 51 extends out of the mounting slot 22 under the elastic action of the second elastic member 52 to support the battery cell 1 to be hot pressed. At this time, the battery cell 1 to be hot pressed is spaced apart from the elastic thermal conductive pad 3. The staff can adjust the position of the battery cell 1 to be hot pressed as needed, so that the body area 11 and the thinning area 12 of the battery cell 1 to be hot pressed correspond to the positions of the first hot pressing area 31 and the second hot pressing area 32 of the elastic thermal conductive pad 3, respectively. In the retracted state, the support column 51 retracts into the mounting groove 22 under the elastic action of the second elastic member 52, and the end of the support column 51 facing away from the second elastic member 52 is flush with the surface of the elastic thermally conductive pad 3. At this time, the elastic thermally conductive pad 3 abuts against the battery cell 1 to be hot pressed, and the main body area 11 of the battery cell 1 to be hot pressed abuts against the first hot pressing area 31, and the thinning area 12 abuts against the second hot pressing area 32, so that the elastic thermally conductive pad 3 fits tightly against the battery cell 1 to be hot pressed, which is beneficial to improving the effect of hot pressing.

[0085] It should be noted that, since the elastic thermal pad 3 is usually a complete pad, in order to prevent the elastic thermal pad 3 from affecting the expansion and contraction of the elastic support assembly 5, the elastic thermal pad 3 is provided with a through hole at the corresponding position of the elastic support assembly 5, so that the support column 51 can extend relative to the installation groove 22 or retract into the installation groove 22. In practical applications, in order to reliably support the hot pressed battery 1, there are multiple elastic support assemblies 5, and the multiple elastic support assemblies 5 are distributed in an array along the second direction Y and the third direction Z. Figure 5As shown, in one embodiment, eight elastic support components 5 are provided, and the eight elastic support components 5 are arranged in two rows and four columns along the second direction Y and the third direction Z, and are all located within the projection range of the first hot pressing zone 31 along the first direction X; correspondingly, the first hot pressing zone 31 is provided with eight through holes at the corresponding positions of the elastic support components 5.

[0086] In practical applications, the hot pressing assembly includes an upper hot pressing assembly and a lower hot pressing assembly, wherein the lower hot pressing assembly is fixed, and the upper hot pressing assembly moves relative to the lower hot pressing assembly to perform hot pressing on the battery cell 1 to be hot pressed. The lower hot pressing assembly includes a first elastic support assembly, and the upper hot pressing assembly includes a second elastic support assembly. During the loading and unloading process of the battery cell 1 to be hot pressed, the first elastic support assembly is mainly used to support the battery cell 1 to be hot pressed, and the second elastic support assembly is mainly used to assist in positioning the battery cell 1 to be hot pressed. Therefore, under normal circumstances, the elastic force of the first elastic support assembly is greater than the elastic force of the second elastic support assembly, that is, the spring of the first elastic support assembly has a first elastic coefficient, and the spring of the second elastic support assembly has a second elastic coefficient, and the second elastic coefficient is smaller than the first elastic coefficient.

[0087] The following provides an example of a process of hot pressing a hot pressing battery cell 1 using the hot pressing mechanism of an embodiment of the present application:

[0088] First, the battery cell 1 to be hot-pressed is placed on the elastic support assembly 5 of the lower hot-pressing assembly by using a material clamp;

[0089] Secondly, move the upper hot pressing assembly downward so that the elastic support assembly 5 of the upper hot pressing assembly contacts the battery cell 1 to be hot pressed. At this time, the material clamp can be removed.

[0090] Next, the upper hot pressing assembly is continuously moved downward, and the elastic support assembly 5 of the upper hot pressing assembly is continuously retracted until the elastic heat conductive pad 3 of the upper hot pressing assembly abuts against the battery cell 1 to be hot pressed;

[0091] Finally, continue to move the upper hot pressing assembly downward, and the elastic support assembly 5 of the lower hot pressing assembly continuously retracts until the elastic thermal conductive pad 3 of the lower hot pressing assembly abuts against the battery cell 1 to be hot pressed. At this point, the battery cell 1 to be hot pressed is tightly fitted with the elastic thermal conductive pads 3 of the upper and lower hot pressing assemblies, so that the surface of the battery cell 1 to be hot pressed is subjected to uniform thermal pressure.

[0092] In summary, the hot pressing mechanism provided in the embodiment of the present application has at least the following advantages:

[0093] In the embodiment of the present application, the hot pressing mechanism includes: two hot pressing components arranged opposite to each other along the first direction, and there is a hot pressing space between the two hot pressing components suitable for accommodating the battery cell to be hot pressed; the hot pressing component includes a hot pressing plate, an elastic heat conductive pad, and an elastic structure arranged between the hot pressing plate and the elastic heat conductive pad, the elastic heat conductive pad is close to the hot pressing space, and the elastic heat conductive pad is elastically connected to the hot pressing plate through the elastic structure. In this way, since the elastic heat conductive pad and the elastic structure are provided, under the elastic action of the elastic structure, the elastic heat conductive pad can be adaptively deformed to fit the battery cell to be hot pressed. That is, during the hot pressing process, the elastic heat conductive pad can be tightly fitted with the battery cell to be hot pressed as a whole, so that the surface of the battery cell to be hot pressed is subjected to uniform heat pressure, which can effectively avoid the problem that the heat pressure is difficult to be transmitted to the thinning area, thereby improving the thermal polymerization bonding effect of the diaphragm glue layer in the thinning area and the battery cell to be hot pressed, which is conducive to improving the overall yield rate of the battery cell.

[0094] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0095] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A hot pressing mechanism, applied to a battery cell to be hot pressed, characterized in that: The hot pressing mechanism comprises: two hot pressing components arranged opposite to each other along a first direction, and a hot pressing space suitable for accommodating the battery core to be hot pressed is provided between the two hot pressing components; The hot pressing assembly includes a hot pressing plate, an elastic heat-conducting pad, and an elastic structure arranged between the hot pressing plate and the elastic heat-conducting pad, wherein the elastic structure is connected to the hot pressing plate and the elastic heat-conducting pad respectively; The elastic heat-conducting pad is arranged close to the hot pressing space, and the elastic heat-conducting pad is used to abut against the battery core to be hot pressed.

2. The hot pressing mechanism according to claim 1, characterized in that: The electric core to be hot pressed comprises a body region and a thinned region, and the thickness of the thinned region is smaller than the thickness of the body region; The elastic thermally conductive pad includes a first hot pressing area and a second hot pressing area, wherein the first hot pressing area is used to abut against the body area, and the second hot pressing area is used to abut against the thinning area; The elastic structure is arranged between the hot pressing plate and the second hot pressing zone, so that the second hot pressing zone is deformed to fit the thinning zone.

3. The hot pressing mechanism according to claim 2, characterized in that: The length direction of the elastic thermal conductive pad is a second direction, and the second direction is perpendicular to the first direction; There are two second hot pressing zones, and the two second hot pressing zones are respectively located on both sides of the first hot pressing zone along the second direction; The elastic structure is provided in two groups, and one group of the elastic structure is provided between one of the second hot pressing zones and the hot pressing plate.

4. The hot pressing mechanism according to claim 2, characterized in that: The elastic heat-conducting pad is detachably connected to the heat pressing plate.

5. The hot pressing mechanism according to claim 4, characterized in that: The elastic heat-conducting pad is threadedly connected to the heat-pressing plate.

6. The hot pressing mechanism according to claim 5, characterized in that: A threaded sleeve is provided on one side of the first hot pressing zone close to the hot pressing plate; The hot pressing assembly further includes a bolt, which is arranged to penetrate the hot pressing plate along the first direction and is threadedly connected to the threaded sleeve.

7. The hot pressing mechanism according to claim 6, characterized in that: The length direction of the elastic thermally conductive pad is the second direction, the width direction of the elastic thermally conductive pad is the third direction, and the first direction, the second direction, and the third direction are perpendicular to each other; The threaded sleeves are provided in plurality, and the plurality of threaded sleeves are distributed in an array along the second direction and the third direction; A plurality of the bolts are provided, and one of the bolts is cooperatively connected with one of the threaded sleeves.

8. The hot pressing mechanism according to claim 1, characterized in that: The heat pressing plate has a first thermal conductivity, and the elastic thermal conductive pad has a second thermal conductivity, and the second thermal conductivity is greater than the first thermal conductivity.

9. The hot pressing mechanism according to claim 1, characterized in that: The elastic structure includes a first elastic member that can be stretched and retracted along the first direction, and the first elastic member is used to drive the elastic thermal conductive pad to deform so as to fit the battery core to be hot pressed.

10. The hot pressing mechanism according to claim 9, characterized in that: The first elastic member is a disc spring.

11. The hot pressing mechanism according to claim 9, characterized in that: The first elastic member is a coil spring.

12. The hot pressing mechanism according to claim 9, characterized in that: The first elastic member is a leaf spring.

13. The hot pressing mechanism according to claim 9, characterized in that: The hot pressing plate is provided with a guide hole, and the guide hole is extended along the first direction; The elastic structure further comprises a guide assembly, the guide assembly is slidably connected to the guide hole along the first direction, and at least a portion of the guide assembly abuts against the elastic thermal conductive pad; The first elastic member is sleeved on the guide assembly. Under the expansion and contraction action of the first elastic member, the guide assembly slides along the first direction to deform the elastic thermal conductive pad.

14. The hot pressing mechanism according to claim 13, characterized in that: The guide assembly comprises: a guide post, a first limiting member and a second limiting member; The guide post is slidably connected to the guide hole; The first elastic member is sleeved on the guide column, and under the expansion and contraction action of the first elastic member, the guide column slides along the first direction; The first limit member and the second limit member are respectively arranged at the two ends of the guide column along the first direction, and the second limit member is close to the elastic thermal conductive pad and abuts against the elastic thermal conductive pad; the first limit member and the second limit member are used to limit the sliding of the guide column to limit the deformation degree of the elastic thermal conductive pad.

15. The hot pressing mechanism according to claim 14, characterized in that: The guide hole comprises: a first guide hole and a second guide hole arranged along the first direction and connected to each other, the first guide hole and the second guide hole are coaxially arranged, and the second guide hole is close to the elastic thermal conductive pad; The inner diameter of the second guide hole is larger than the inner diameter of the first guide hole, and at least part of the second limiting member is engaged with the second guide hole to limit the second limiting member; A limiting flange is further provided at one end of the first guide hole away from the second guide hole, and the limiting flange is used to abut against the first limiting member to limit the first limiting member.

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