Pole piece rolling device
By using a roller heating assembly to conduct heat to the metal foil layer in the electrode sheet rolling device, the layering problem caused by the difference in ductility of the metal foil layer and the polymer base film is solved, and the reliability of the electrode sheet is improved.
Patent Information
- Application Number
- CN202422112965.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-29
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-08-29
AI Technical Summary
There is a large gap in the ductility between the metal foil layer and the polymer base film in the composite liquid collecting fluid, which leads to easy layering during the rolling process, affecting the reliability of the electrode sheet.
By introducing a roller heating assembly into the electrode sheet roller pressing device, the active material layer is heated, and heat is transmitted to the metal foil layer of the composite fluid collection, increasing its ductility and reducing its impact on the ductility of the polymer base film.
The ductility gap between the metal foil layer and the polymer base film is effectively narrowed, layering phenomenon is avoided under rolling stress, and the reliability of the electrode sheet is improved.
Smart Images
Figure CN222985231U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of batteries and relates to a pole piece rolling device. Background Art
[0002] The pole piece includes a current collector and an active material layer disposed on the current collector. The current collector usually uses a metal foil. To improve the safety performance of lithium-ion batteries, metal foils are usually laminated on both surfaces of a polymer-based film to form a composite current collector. The composite current collector can prevent lithium-ion batteries from catching fire, exploding, etc. due to internal short circuits in case of abnormal situations such as collision, extrusion, and puncture. By rolling and laminating the composite current collector and the active material layer, the pole piece can be obtained.
[0003] However, the metal foil layer in the composite current collector has less ductility than the polymer-based film, which may cause delamination between the metal foil layer and the polymer-based film when subjected to rolling stress, affecting the reliability of the pole piece. Therefore, how to narrow the ductility gap between the metal foil layer and the polymer-based film and avoid delamination between the metal foil layer and the polymer-based film is an urgent problem to be solved. Summary of the Utility Model
[0004] Aiming at the deficiencies of the prior art, the purpose of the utility model is to provide a pole piece rolling device. The utility model heats the active material layer through a roller heating component. After the active material layer is heated, it enters the rolling mechanism together with the composite current collector for rolling and lamination. The heat of the active material layer can be conducted to the metal foil layer of the composite current collector. Since the metal foil layer heats up quickly, the ductility of the metal foil layer can be increased, and this method can reduce the influence on the ductility of the polymer-based film, thereby narrowing the ductility gap between the metal foil layer and the polymer-based film and further avoiding delamination between the metal foil layer and the polymer-based film when subjected to rolling stress.
[0005] To achieve this purpose, the utility model adopts the following technical solutions:
[0006] The utility model provides a pole piece rolling device, which comprises:
[0007] A first unwinding mechanism for supplying a composite current collector to the downstream. The composite current collector includes a polymer-based film and metal foil layers disposed on both surfaces of the polymer-based film;
[0008] A second unwinding mechanism for supplying an active material layer to the downstream;
[0009] A roller heating component disposed downstream of the second unwinding mechanism for heating the active material layer;
[0010] The rolling mechanism is arranged downstream of the first unwinding mechanism and the roller heating assembly, and is used to roll and compound the composite current collector and the heated active material layer to form a pole piece.
[0011] In the present utility model, the active material layer is heated by the roller heating assembly. After being heated, the active material layer and the composite current collector enter the rolling mechanism together for rolling and compounding. The heat of the active material layer can be conducted to the metal foil layer of the composite current collector, which can increase the ductility of the metal foil layer. Moreover, this method can reduce the influence on the ductility of the polymer-based film, so as to narrow the ductility gap between the metal foil layer and the polymer-based film, and further avoid the delamination phenomenon of the metal foil layer and the polymer-based film when subjected to rolling stress.
[0012] Preferably, the pole piece rolling device includes two groups of second unwinding mechanisms and two groups of roller heating assemblies; the two groups of second unwinding mechanisms are respectively located on both sides of the advancing direction of the composite current collector; the two groups of roller heating assemblies are respectively arranged in one-to-one correspondence with the two groups of second unwinding mechanisms.
[0013] Preferably, the second unwinding mechanism includes an active material layer unwinding roller.
[0014] Preferably, the second unwinding mechanism includes two forming rollers arranged in parallel and rotating relatively synchronously, which are used to extrude the active material layer raw material to form an active material layer.
[0015] Preferably, the roller heating assembly includes a single heating roller, which is used to heat one side of the active material layer facing the composite current collector.
[0016] Preferably, the wrap angle of the single heating roller is 90° to 270°.
[0017] Preferably, the roller heating assembly includes two parallel heating rollers, and there is a gap for the active material layer to pass through between the outer circumferential surfaces of the two heating rollers.
[0018] Preferably, the rolling mechanism includes a normal temperature rolling assembly, which is used to roll and compound the composite current collector and the heated active material layer at normal temperature.
[0019] Preferably, the rolling mechanism further includes a hot rolling assembly, and the hot rolling assembly is arranged downstream of the normal temperature rolling assembly, and is used to perform hot rolling and compounding on the material obtained by normal temperature rolling and compounding.
[0020] Preferably, the pole piece rolling device further includes a winding mechanism, and the winding mechanism is arranged downstream of the rolling mechanism and is used to collect the pole pieces.
[0021] Compared with the prior art, the beneficial effects of the present utility model are:
[0022] The utility model heats the active material layer through a roller heating assembly. After the active material layer is heated, it enters a rolling mechanism together with the composite current collector for rolling and compounding. The heat of the active material layer can be conducted to the metal foil layer of the composite current collector. Since the metal foil layer is heated quickly, the ductility of the metal foil layer can be increased, and this method can reduce the influence on the ductility of the polymer base film, so as to narrow the ductility gap between the metal foil layer and the polymer base film, and further avoid the delamination phenomenon of the metal foil layer and the polymer base film when subjected to rolling stress. Description of the Drawings
[0023] Figure 1 It is a schematic structural diagram of the pole piece rolling device provided in Embodiment 1 of the utility model;
[0024] Figure 2 It is a schematic structural diagram of the pole piece rolling device provided in Embodiment 2 of the utility model;
[0025] Figure 3 It is a schematic structural diagram of the pole piece rolling device provided in Embodiment 3 of the utility model;
[0026] Among them, 11 - composite current collector unwinding roller; 12 - active material layer unwinding roller; 13 - forming roller; 21 - first heating roller; 22 - second heating roller; 31 - composite current collector; 32 - active material layer; 4 - normal temperature rolling assembly; 5 - winding roller; 6 - hot rolling assembly. Detailed Embodiments
[0027] It should be understood that in the description of the present utility model, the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features.
[0028] It should be noted that in the description of the present utility model, unless otherwise clearly defined and limited, the terms "arranged", "connected", and "coupled" shall 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0029] The technical solution of the present utility model will be further described below with reference to the accompanying drawings and through specific embodiments.
[0030] In one embodiment, the present utility model provides a pole piece rolling device, which includes:
[0031] A first unwinding mechanism for supplying a composite current collector to the downstream, where the composite current collector includes a polymer-based film and metal foil layers provided on both surface sides of the polymer-based film;
[0032] A second unwinding mechanism for supplying an active material layer to the downstream;
[0033] A roller heating assembly arranged downstream of the second unwinding mechanism for heating the active material layer;
[0034] A rolling mechanism arranged downstream of the first unwinding mechanism and the roller heating assembly for rolling and laminating the composite current collector and the heated active material layer to form a pole piece.
[0035] It should be noted that the active material layer is a dry film material, and operations such as heating and rolling can be performed on it.
[0036] In the present utility model, the roller heating assembly heats the active material layer. After the active material layer is heated, it enters the rolling mechanism together with the composite current collector for rolling and laminating. The heat of the active material layer can be conducted to the metal foil layer of the composite current collector. Since the metal foil layer heats up quickly, the ductility of the metal foil layer can be increased, and this method can reduce the influence on the ductility of the polymer-based film, thereby being able to narrow the ductility gap between the metal foil layer and the polymer-based film, and further avoiding the delamination phenomenon when the metal foil layer and the polymer-based film are subjected to rolling stress.
[0037] In one embodiment, the active material layer is composed of an active material, a conductive agent, and a binder. The active material can be a positive electrode active material or a negative electrode active material. The present utility model does not limit the specific types of the positive electrode active material, the negative electrode active material, the conductive agent, and the binder, and can be selected according to actual needs.
[0038] In one embodiment, the pole piece rolling device includes two groups of second unwinding mechanisms and two groups of roller heating components; the two groups of second unwinding mechanisms are respectively located on both sides of the advancing direction of the composite current collector; the two groups of roller heating components are respectively arranged in one-to-one correspondence with the two groups of second unwinding mechanisms.
[0039] In the present utility model, when the pole piece rolling device includes two groups of second unwinding mechanisms and two groups of roller heating components, one group of second unwinding mechanism and one group of roller heating components are respectively provided on both sides of the advancing direction of the composite current collector, so as to realize the heating of the two active material layers; the two heated active material layers are respectively located on both sides of the composite current collector, and enter the rolling mechanism together with the composite current collector for rolling and compounding, so that the active material layers are simultaneously compounded on the surfaces of the metal foil layers on both sides of the composite current collector.
[0040] In one embodiment, the first unwinding mechanism includes a composite current collector unwinding roller.
[0041] In the present utility model, the finished composite current collector is wound on the composite current collector unwinding roller, and the composite current collector can be directly provided to the downstream.
[0042] In one embodiment, the second unwinding mechanism includes an active material layer unwinding roller.
[0043] In the present utility model, the finished active material layer is wound on the active material layer unwinding roller, and the active material layer can be directly provided to the downstream.
[0044] In one embodiment, the second unwinding mechanism includes two forming rollers arranged in parallel and rotating relatively synchronously, which are used for extruding the active material layer raw material to form the active material layer.
[0045] In the present utility model, there is a forming channel between the two forming rollers arranged in parallel and rotating relatively synchronously. The active material layer raw material is poured between the two forming rollers, and the formed active material layer is provided to the downstream after being extruded by the two forming rollers.
[0046] It should be noted that the distance between the two forming rollers determines the thickness of the formed active material layer, and the specific distance can be adjusted according to production requirements. The active material layer raw material is a mixture of active material, conductive agent and binder.
[0047] In one embodiment, the two forming rollers are arranged in parallel on a horizontal plane.
[0048] In one embodiment, the roller heating component includes a single heating roller, which is used for heating one side of the active material layer facing the composite current collector.
[0049] In the present utility model, when the roller heating assembly includes a single heating roller, the side of the active material layer facing the composite current collector is heated, which is beneficial to transfer the heat of the active material layer to the metal foil layer.
[0050] In one embodiment, the wrap angle of the single heating roller is 90° to 270°, for example, it can be 90°, 100°, 120°, 150°, 180°, 200°, 220°, 250° or 270°, etc., but it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.
[0051] In the present utility model, when a single heating roller is used to heat the active material layer, the active material layer forms a large wrap angle on the heating roller, and the wrap angle is 90° to 270°, which can increase the heating duration of the active material layer, thereby ensuring the heating effect on the composite current collector.
[0052] In one embodiment, the roller heating assembly includes two parallel heating rollers, and there is a gap for the active material layer to pass between the outer circumferential surfaces of the two heating rollers.
[0053] In the present utility model, when two heating rollers are used to heat the active material layer, the active material layer passes through the gap between the two heating rollers, and double-sided heating of the active material layer can be realized, ensuring the heating effect on the composite current collector.
[0054] In the present utility model, when the roller heating assembly includes a single heating roller or two heating rollers, heating of the active material layer can be realized, and it can be set according to actual needs.
[0055] In one embodiment, the rolling mechanism includes a normal-temperature rolling assembly for performing normal-temperature rolling and lamination on the composite current collector and the heated active material layer.
[0056] In the present utility model, after the composite current collector and the heated active material layer are subjected to normal-temperature rolling and lamination through the normal-temperature rolling assembly, a pole piece can be obtained.
[0057] In one embodiment, the normal-temperature rolling assembly includes a cooperating upper normal-temperature pressing roller and a lower normal-temperature pressing roller.
[0058] In one embodiment, the rolling mechanism further includes a hot rolling assembly, and the hot rolling assembly is arranged downstream of the normal-temperature rolling assembly for performing hot rolling and lamination on the material obtained after normal-temperature rolling and lamination.
[0059] It should be noted that the temperature of hot rolling and lamination is higher than that of normal-temperature rolling and lamination.
[0060] In the present utility model, a hot rolling assembly is provided downstream of the normal-temperature rolling assembly. The material obtained after normal-temperature rolling and lamination enters the hot rolling assembly for hot rolling and lamination. The hot rolling assembly can further laminate and compact the active material layer thinly, and the hot rolling assembly heats the active material layer, and heat conduction is carried out on the metal foil layer on the composite current collector by the active material layer, which helps to increase the ductility of the metal foil layer, so that the metal foil layer can be extended together with the polymer-based film when being pressed, thereby further solving the delamination problem between the metal foil layer and the polymer-based film. The pole piece obtained by two-time rolling and lamination has higher reliability.
[0061] In one embodiment, the hot rolling assembly includes a cooperating upper hot pressing roller and a lower hot pressing roller.
[0062] In one embodiment, the pole piece rolling device further includes a winding mechanism, and the winding mechanism is arranged downstream of the rolling mechanism for collecting the pole piece.
[0063] In one embodiment, the winding mechanism includes a winding roller for collecting the pole piece.
[0064] Example 1
[0065] This embodiment provides a pole piece rolling device, the structure of which is as Figure 1 shown, including a first unwinding mechanism, two groups of second unwinding mechanisms, two groups of roller heating assemblies, a rolling mechanism and a winding mechanism;
[0066] The first unwinding mechanism includes a composite current collector unwinding roller 11 for providing a composite current collector 31 to the downstream. The composite current collector 31 includes a polymer-based film and metal foil layers arranged on both surface sides of the polymer-based film;
[0067] The two groups of second unwinding mechanisms are respectively located on both sides of the advancing direction of the composite current collector 31; each group of second unwinding mechanisms includes an active material layer unwinding roller 12 for providing an active material layer 32 to the downstream;
[0068] The two groups of roller heating assemblies are respectively located on both sides of the advancing direction of the composite current collector 31 and are respectively arranged downstream of the two groups of second unwinding mechanisms in one-to-one correspondence; each group of roller heating assemblies includes a single heating roller, denoted as a first heating roller 21, for heating one side of the active material layer 32 facing the composite current collector 31; the wrap angle of the first heating roller 21 is 95°;
[0069] The rolling mechanism consists of a normal-temperature rolling assembly 4. The normal-temperature rolling assembly 4 is arranged downstream of the first unwinding mechanism and the two groups of roller heating assemblies; the normal-temperature rolling assembly 4 includes a cooperating upper normal-temperature pressing roller and a lower normal-temperature pressing roller for performing normal-temperature rolling and lamination on the composite current collector 31 and the heated active material layer 32 to form a pole piece;
[0070] The winding mechanism includes a winding roller 5, which is arranged downstream of the normal-temperature rolling assembly 4 and is used to collect the electrode sheet.
[0071] Embodiment 2
[0072] This embodiment provides a device for rolling an electrode sheet, and its structure is as Figure 2 shown, and it includes a first unwinding mechanism, two groups of second unwinding mechanisms, two groups of roller heating assemblies, a rolling mechanism and a winding mechanism:
[0073] The first unwinding mechanism includes a composite current collector unwinding roller 11, which is used to provide a composite current collector 31 to the downstream. The composite current collector 31 includes a polymer-based film and metal foil layers arranged on both surface sides of the polymer-based film;
[0074] The two groups of second unwinding mechanisms are respectively located on both sides of the advancing direction of the composite current collector 31; each group of second unwinding mechanisms includes an active material layer unwinding roller 12, which is used to provide an active material layer 32 to the downstream;
[0075] The two groups of roller heating assemblies are respectively located on both sides of the advancing direction of the composite current collector 31, and are respectively arranged downstream of the two groups of second unwinding mechanisms in a one-to-one correspondence; each group of roller heating assemblies includes two heating rollers, which are respectively denoted as a first heating roller 21 and a second heating roller 22. The first heating roller 21 and the second heating roller 22 are parallel to each other, and there is a gap for the active material layer 32 to pass through between the outer circumferential surfaces of the first heating roller 21 and the second heating roller 22, and are used to heat both surface sides of the active material layer 32;
[0076] The rolling mechanism is composed of a normal-temperature rolling assembly 4, and the normal-temperature rolling assembly 4 is arranged downstream of the first unwinding mechanism and the two groups of roller heating assemblies; the normal-temperature rolling assembly 4 includes a cooperating upper normal-temperature pressing roller and a lower normal-temperature pressing roller, and is used to perform normal-temperature rolling and compounding on the composite current collector 31 and the heated active material layer 32 to form an electrode sheet;
[0077] The winding mechanism includes a winding roller 5, which is arranged downstream of the normal-temperature rolling assembly 4 and is used to collect the electrode sheet.
[0078] Embodiment 3
[0079] This embodiment provides a device for rolling an electrode sheet, and its structure is as Figure 3 shown, and it includes a first unwinding mechanism, two groups of second unwinding mechanisms, two groups of roller heating assemblies, a rolling mechanism and a winding mechanism:
[0080] The first unwinding mechanism includes a composite current collector unwinding roller 11, which is used to provide a composite current collector 31 to the downstream. The composite current collector 31 includes a polymer-based film and metal foil layers arranged on both surface sides of the polymer-based film;
[0081] Two sets of second unwinding mechanisms are respectively located on both sides of the advancing direction of the composite current collector 31; each set of second unwinding mechanisms includes two forming rollers 13, and the two forming rollers 13 are arranged in parallel on a horizontal plane and rotate relatively synchronously, for extruding the raw material of the active material layer 32 to form the active material layer 32 and supplying it downstream;
[0082] Two sets of roller heating assemblies are respectively located on both sides of the advancing direction of the composite current collector 31, and are respectively arranged downstream of the two sets of second unwinding mechanisms in one-to-one correspondence; each set of roller heating assemblies includes two heating rollers, denoted as the first heating roller 21 and the second heating roller 22 respectively. The first heating roller 21 and the second heating roller 22 are parallel to each other, and there is a gap for the active material layer 32 to pass between the outer circumferential surfaces of the first heating roller 21 and the second heating roller 22, for heating the two side surfaces of the active material layer 32;
[0083] The rolling mechanism is composed of a normal-temperature rolling assembly 4 and a hot rolling assembly 6. The normal-temperature rolling assembly 4 is arranged downstream of the first unwinding mechanism and the two sets of roller heating assemblies, and the hot rolling assembly 6 is arranged downstream of the normal-temperature rolling assembly 4; the normal-temperature rolling assembly 4 includes a cooperating upper normal-temperature pressing roller and a lower normal-temperature pressing roller, for performing normal-temperature rolling and compounding on the composite current collector 31 and the heated active material layer 32 to form an initial pole piece; the hot rolling assembly 6 includes a cooperating upper hot pressing roller and a lower hot pressing roller, for performing hot rolling and compounding on the initial pole piece to finally form a pole piece;
[0084] The winding mechanism includes a winding roller 5, and the winding roller 5 is arranged downstream of the hot rolling assembly 6, for collecting the pole pieces.
[0085] In summary, the present utility model heats the active material layer through the roller heating assembly, and the heat of the active material layer can be conducted to the metal foil layer of the composite current collector. Since the metal foil layer is heated quickly, the ductility of the metal foil layer can be increased, and the influence on the ductility of the polymer-based film can be reduced. Thus, the ductility gap between the metal foil layer and the polymer-based film can be narrowed, and further, the delamination phenomenon of the metal foil layer and the polymer-based film under the rolling stress can be avoided, and a pole piece with high reliability can be obtained.
[0086] The above are only the specific embodiments of the present utility model, but the protection scope of the present utility model is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present utility model fall within the protection scope and the disclosure scope of the present utility model.
Claims
1. A pole piece rolling device, characterized in that: The pole piece rolling device comprises: A first unwinding mechanism, used for providing a composite current collector to a downstream, wherein the composite current collector comprises a polymer base film and a metal foil layer disposed on both sides of the polymer base film; a second unwinding mechanism, for providing the active material layer downstream; A roller heating assembly, disposed downstream of the second unwinding mechanism, for heating the active material layer; The rolling mechanism is arranged downstream of the first unwinding mechanism and the roller heating assembly, and is used for rolling and compounding the composite current collector and the heated active material layer to form a pole piece.
2. The pole piece rolling device according to claim 1, characterized in that: The pole piece rolling device comprises two sets of second unwinding mechanisms and two sets of roller heating assemblies; The two sets of second unwinding mechanisms are respectively located on both sides of the composite current collector's traveling direction; The two groups of roller heating components are respectively arranged in one-to-one correspondence with the two groups of second unwinding mechanisms.
3. The pole piece rolling device according to claim 1 or 2, characterized in that: The second unwinding mechanism includes an active material layer unwinding roller.
4. The pole piece rolling device according to claim 1 or 2, characterized in that: The second unwinding mechanism includes two forming rollers which are arranged in parallel and rotate synchronously relative to each other and are used for extruding the active material layer raw material to form the active material layer.
5. The pole piece rolling device according to claim 1 or 2, characterized in that: The roller heating assembly includes a single heating roller for heating a side of the active material layer facing the composite current collector.
6. The pole piece rolling device according to claim 5, characterized in that: The wrap angle of the single heating roller is 90° to 270°.
7. The pole piece rolling device according to claim 1 or 2, characterized in that: The roller heating assembly comprises two mutually parallel heating rollers, and a gap is provided between the outer circumferential surfaces of the two heating rollers for the active material layer to pass through.
8. The pole piece rolling device according to claim 1 or 2, characterized in that: The rolling mechanism comprises a room temperature rolling assembly, which is used for performing room temperature rolling compounding of the composite current collector and the heated active material layer.
9. The pole piece rolling device according to claim 8, characterized in that: The rolling mechanism further comprises a hot rolling assembly, which is arranged downstream of the normal temperature rolling assembly and is used for hot rolling laminating the material obtained after normal temperature rolling lamination.
10. The pole piece rolling device according to claim 1 or 2, characterized in that: The pole piece rolling device further comprises a winding mechanism, which is arranged downstream of the rolling mechanism and is used for collecting pole pieces.