Device and method for preparing pole piece

Abstract

The invention discloses a device and a method for preparing a pole piece, which can improve the thickness consistency of the pole piece. The device comprises a material extruding device used for extruding materials into sheet materials; and the rolling device is arranged at the downstream of the material extruding device and is used for rolling the sheet material to form the pole piece.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a device and method for preparing a pole piece. Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. In this case, electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development. The preparation quality of the pole piece in the battery directly affects the performance of the battery. Therefore, how to improve the preparation quality of the pole piece has become a problem that needs to be solved. Summary of the invention

[0003] The embodiments of the present application provide a device and method for preparing a pole piece, which can improve the consistency of the thickness of the pole piece.

[0004] In a first aspect, a device for preparing a pole piece is provided, the device comprising: an extrusion device for extruding a material into a sheet; and a rolling device, arranged downstream of the extrusion device, for rolling the sheet to form a pole piece.

[0005] The device for preparing the electrode sheet in the embodiment of the present application includes an extruder and a roller pressing device, wherein the extruder is used to extrude the material into a sheet, and the roller pressing device is used to roll the sheet into the electrode sheet. Because the extruder pre-extrudes the material into a sheet before the material enters the roller pressing device, and then rolls the sheet, the material has a regular morphology and a relatively uniform thickness before entering the roller pressing device, which greatly improves the consistency of the thickness of the electrode sheet formed after rolling, and makes the thickness of the electrode sheet finally obtained more uniform.

[0006] In a possible implementation, the extrusion device includes a feeding mechanism and an extrusion die head connected to the feeding mechanism, the feeding mechanism is used to transfer the material to the extrusion die head, and the extrusion die head is used to extrude the material to form the sheet material.

[0007] In this embodiment, the extrusion device may include a feeding mechanism and an extrusion die. The feeding mechanism transfers the material to the extrusion die, and the extrusion die extrude the material to form a sheet. In this way, the sheet can be formed smoothly through feeding and extruding.

[0008] In some possible implementations, the extrusion die head includes an inlet connected to the feeding mechanism, an outlet for outputting the sheet material, and a flow channel connecting the inlet and the outlet, and the size of the flow channel gradually increases from the inlet to the outlet.

[0009] In this embodiment, the inlet on the extrusion die is connected to the feeding mechanism, and the outlet of the extrusion die is used to output the sheet material. The flow channel between the inlet and the outlet is hanger-shaped, and the size gradually increases from the inlet to the outlet, which can effectively guide the material.

[0010] In a possible implementation, the feeding mechanism includes a base, and a motor and a screw structure disposed on the base, wherein the motor is used to drive the screw structure to rotate. The feeding mechanism may be, for example, a single screw structure, a twin screw structure, or a multi-screw structure. The use of a screw structure to achieve feeding has high feeding efficiency and feeding stability, and because the feeding speed is positively correlated with the screw speed, it has good adjustability.

[0011] In a possible implementation, the device also includes: a roller, which is arranged between the extrusion device and the rolling device; and a tension detection mechanism, which is arranged on one side of the roller and is used to detect the tension of the sheet when the sheet passes through the other side of the roller.

[0012] In this embodiment, a tension detection mechanism is provided to detect the tension of the sheet when the sheet passes through the rollers, thereby effectively monitoring the state of the sheet before entering the roller pressing device and improving the consistency of the sheet entering the rollers.

[0013] In a possible implementation, the device further includes: a control module, configured to receive a detection result of the tension detection mechanism, and adjust an extrusion speed of the extrusion device according to the detection result.

[0014] In this embodiment, the control module can perform closed-loop adjustment on the extrusion speed of the extrusion device according to the detection result fed back by the tension detection mechanism, so as to reduce the probability of material accumulation in the rolling device or the sheet material being overstretched and broken.

[0015] In a possible implementation, the control module is specifically used to: increase the extrusion speed of the extrusion device when the detection result of the tension detection mechanism is greater than a preset tension value; and reduce the extrusion speed of the extrusion device when the detection result of the tension detection mechanism is less than or equal to the tension value.

[0016] It can be understood that when the tension of the sheet material detected by the tension detection mechanism is greater than the preset tension value, it means that the conveying speed of the sheet material is relatively fast, and the extrusion speed of the extrusion device cannot keep up, and the sheet material is prone to over-stretching and breaking. The control module controls the extrusion speed of the extrusion device to increase until the tension detected by the tension detection mechanism drops to a preset tension value, thereby reducing the probability of the sheet material being over-stretched and breaking. When the tension of the sheet material detected by the tension detection mechanism is less than or equal to the preset tension value, it means that the conveying speed of the sheet material is relatively slow and cannot keep up with the extrusion speed of the extrusion device, and the material is prone to accumulation in the rolling device. The control module controls the extrusion speed of the extrusion device to decrease until the tension detected by the tension detection mechanism rises to a preset tension value, thereby reducing the probability of material accumulation in the rolling device.

[0017] In a possible implementation, the control module is also used to: obtain a preset relationship, which is used to express the relationship between the extrusion speed and the conveying speed of the sheet; determine a target extrusion speed that matches the conveying speed based on the conveying speed of the sheet and the relationship; and adjust the initial extrusion speed of the extrusion device to the target extrusion speed.

[0018] In this embodiment, the initial extrusion speed of the extrusion device can be set based on a preset relationship, which is used to express the relationship between the extrusion speed and the sheet material conveying speed. According to the initially set sheet material conveying speed and based on the relationship, the initial extrusion speed of the extrusion device can be calculated, so that the extrusion speed matches the sheet material conveying speed, which greatly saves the subsequent adjustment time for the extrusion speed and improves production efficiency.

[0019] In a possible implementation, the rolling device includes a first thinning roller and a second thinning roller, the first thinning roller and the second thinning roller are arranged on both sides of the sheet material to thin the sheet material. The first thinning roller and the second thinning roller can effectively thin the sheet material.

[0020] In a possible implementation, the rolling device further includes at least two rolling rollers for rolling the thinned sheet at least once. The thickness consistency of the pole piece can be further improved by rolling the thinned sheet again with multiple rolling rollers.

[0021] In a possible implementation, the roller pressing device further includes a feeding device for conveying the material to the extruding device. The feeding device is used to store the material and convey the material to the extruding device.

[0022] In a second aspect, a method for preparing a pole piece is provided, which is applied to a device for preparing a pole piece, the device comprising an extrusion device and a rolling device, the rolling device being arranged downstream of the extrusion device, the method comprising: controlling the extrusion device to extrude the material to form a sheet; controlling the rolling device to roll the sheet to form a pole piece.

[0023] In a possible implementation, the device also includes a roller and a tension detection mechanism, the roller is arranged between the extrusion device and the rolling device, and the tension detection mechanism is arranged on one side of the roller, for detecting the tension of the sheet when the sheet passes through the other side of the roller.

[0024] In a possible implementation, the method further includes: receiving a detection result of the tension detection mechanism; and adjusting an extrusion speed of the extrusion device according to the detection result.

[0025] In a possible implementation, adjusting the extrusion speed of the extrusion device according to the detection result includes: when the detection result of the tension detection mechanism is greater than a preset tension value, increasing the extrusion speed of the extrusion device; when the detection result of the tension detection mechanism is less than or equal to the tension value, reducing the extrusion speed of the extrusion device.

[0026] In a possible implementation, the method further includes: obtaining a preset relationship equation, which is used to express the relationship between the extrusion speed and the conveying speed of the sheet; determining a target extrusion speed that matches the conveying speed based on the conveying speed of the sheet and the relationship equation; and adjusting the initial extrusion speed of the extrusion device to the target extrusion speed.

[0027] In some possible implementations, the extrusion die head includes an inlet connected to the feeding mechanism, an outlet for outputting the sheet material, and a flow channel connecting the inlet and the outlet, and the size of the flow channel gradually increases from the inlet to the outlet.

[0028] In a possible implementation, the feeding mechanism includes a base, and a motor and a screw structure disposed on the base, wherein the motor is used to drive the screw structure to rotate. The feeding mechanism may be, for example, a single screw structure, a twin screw structure, or a multi-screw structure.

[0029] In a possible implementation, the rolling device includes a first thinning roller and a second thinning roller, and the first thinning roller and the second thinning roller are arranged on two sides of the sheet material relative to each other, and are used to thin the sheet material.

[0030] In a possible implementation, the rolling device further includes at least two rolling rollers for rolling the thinned sheet at least once.

[0031] In a possible implementation, the rolling device further includes a feeding device for conveying the material to the extruding device.

[0032] In a third aspect, a battery is provided, comprising an electrode assembly, wherein the electrode assembly comprises a pole piece, and the pole piece is prepared by using the apparatus for preparing a pole piece described in the first aspect or any possible implementation of the first aspect, or is prepared by using the method for preparing a pole piece described in the second aspect or any possible implementation of the second aspect.

[0033] In a fourth aspect, an electrical device is provided, comprising the battery described in the third aspect of claim 1 or any possible implementation of the third aspect, wherein the battery is used to provide power for the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without paying creative work.

[0035] Figure 1 It is a schematic block diagram of an apparatus for preparing a pole piece according to an embodiment of the present application.

[0036] Figure 2 It is a schematic block diagram of an apparatus for preparing a pole piece according to another embodiment of the present application.

[0037] Figure 3 yes Figure 2 A schematic structural diagram of a possible specific implementation of the device shown.

[0038] Figure 4 It is a schematic structural diagram of a feeding mechanism according to an embodiment of the present application.

[0039] Figure 5 It is a schematic structural diagram of an extrusion die head according to an embodiment of the present application.

[0040] Figure 6 It is a schematic diagram of the flow channel of the extrusion die head according to an embodiment of the present application.

[0041] Figure 7 It is a schematic structural diagram of a tension detection mechanism according to an embodiment of the present application.

[0042] Figure 8It is a schematic diagram of the process flow of preparing a pole piece according to an embodiment of the present application.

[0043] Fig. 9 It is a schematic flow chart of a method for preparing a pole piece according to an embodiment of the present application. DETAILED DESCRIPTION

[0044] The following detailed description and drawings of the embodiments of the present application are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0045] In the description of the present application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0046] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0047] The battery described in the embodiments of the present application is applicable to various electrical devices using batteries.

[0048] The electrical devices may be, for example, vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc.; the spacecraft may include airplanes, rockets, space shuttles, and spacecrafts, etc.; the electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; the electric tools may include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0049] The battery in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0050] A battery cell may include an electrode assembly and an electrolyte, wherein the electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. A battery cell mainly works by the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, wherein the positive electrode active material layer is coated on the surface of the positive electrode current collector, and the current collector not coated with the positive electrode active material layer protrudes from the current collector coated with the positive electrode active material layer, and the current collector not coated with the positive electrode active material layer serves as the positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, wherein the negative electrode active material layer is coated on the surface of the negative electrode current collector, and the current collector not coated with the negative electrode active material layer protrudes from the current collector coated with the negative electrode active material layer, and the current collector not coated with the negative electrode active material layer serves as the negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be graphite, carbon or silicon, etc. In order to ensure that a large current can be passed without melting, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the diaphragm can be polypropylene (PP) or polyethylene (PE). In addition, the electrode assembly can be a winding structure or a laminated structure, and the embodiments of the present application are not limited thereto.

[0051] The preparation of pole pieces usually includes wet process and dry process. The wet process has obvious disadvantages, such as low solid content of slurry, high solvent content, high drying energy consumption, large equipment investment, and environmental pollution caused by solvents. The main route of the dry process is to fully mix the active material, conductive agent, binder such as polytetrafluoroethylene (PTFE) powder, and then carry out fiberization and granulation, and then put the mixed granular powder into hot rollers for hot rolling, calendering, trimming, and hot compounding to obtain the positive and negative pole pieces of the battery. The dry process also has the following disadvantages: the solvent-free granular powder is directly put between the two rollers, and it is difficult to control the consistency of its lateral thickness; the self-supporting membrane needs to be rolled up first, and then unrolled for hot rolling, calendering, trimming, and hot compounding, which increases the manufacturing process and production efficiency; the material piles between the two rollers during the rolling film forming process, without closed-loop control, the quality of the pole piece is difficult to control, and the yield rate is low.

[0052] In view of this, the present application proposes a solution for preparing pole pieces. Before rolling to form the pole pieces, the sheet material is extruded in advance and then rolled, which can effectively improve the consistency of the thickness of the pole pieces.

[0053] Figure 1 FIG. 1 is a schematic block diagram of a device 100 for preparing a pole piece according to an embodiment of the present application. Figure 1 As shown, the device 100 for preparing a pole piece includes an extrusion device 110 and a rolling device 120. The extrusion device 110 is used to extrude the material 10 to form a sheet 20; the rolling device 120 is arranged downstream of the extrusion device 110, and is used to roll the sheet 20 to form a pole piece 30.

[0054] Because the extrusion device 110 pre-extrudes the material 10 into the sheet 20 before the material 10 enters the rolling device 120, and then rolls the sheet 20, the material 10 has a regular shape and relatively uniform thickness before entering the rolling device 120, which greatly improves the consistency of the thickness of the electrode 30 formed after rolling, and makes the thickness of the final electrode 30 more uniform.

[0055] In some embodiments, Figure 2 As shown, the device 100 also includes a tension detection mechanism 130 arranged between the extrusion device 110 and the rolling device 120, which is used to detect the tension of the sheet material 20 when the sheet material 20 passes through, thereby effectively monitoring the state of the sheet material 20 before entering the rolling device 120, thereby improving the consistency of the sheet material 20 entering the roller.

[0056] As an example, Figure 3 Shows Figure 2 A possible specific implementation of the device 100 shown is as follows: Figure 3As shown, the device 100 includes an extrusion device 110 and a rolling device 120. The material 10 is first formed into a sheet 20 with a regular morphology and uniform thickness in the extrusion device 110, and then the sheet 20 is rolled by the rolling device 120 to obtain a pole piece 30, which can greatly improve the consistency of the thickness of the pole piece 30.

[0057] It can be understood that the pole piece preparation method of directly scattering the material 10 into the rolling device 120 for rolling to form the pole piece 30 is difficult to ensure the consistency of the transverse thickness of the pole piece 30, that is, the thickness in the width direction. However, the pole piece preparation method of the embodiment of the present application is adopted, in which the material 10 is first put into the extrusion device 110 to be extruded to form a thicker but uniform sheet 20, and then the sheet 20 is sent to the rolling device 120 for rolling to form the pole piece 30, which can effectively improve the consistency of the transverse thickness of the pole piece 30 and improve the preparation quality of the pole piece 30.

[0058] In some embodiments, for example, Figure 3 As shown, the roller pressing device 120 further includes a feeding device 150 for conveying the material 10 to the extrusion device 110. The feeding device 150 can be used to store the material 10 and convey the material 10 to the extrusion device 110. The material 10 can be, for example, a uniformly mixed powder or agglomerated material, such as an active substance, a conductive agent, a binder, etc., which is fed into the extrusion device 110 through the feeding device 150.

[0059] The present application does not limit the structure of the rolling device 120. For example, Figure 3 As shown, the rolling device 120 may include a first thinning roller 121 and a second thinning roller 122, which are relatively arranged on both sides of the sheet 20, and are used to thin the thickness of the sheet 20 when the sheet 20 passes between the first thinning roller 121 and the second thinning roller 122.

[0060] For example, Figure 3 As shown, the rolling device 120 may further include at least two rolling rollers 123 for rolling the thinned sheet material 20 at least once.

[0061] The sheet 20 is rolled when passing between the first thinning roller 121 and the second thinning roller 122 , and its thickness is significantly reduced, thereby achieving effective thinning of the sheet 20 . The thinned sheet 20 is rolled again when passing through multiple rolling rollers 123 , which can further improve the consistency of the thickness of the pole piece 30 .

[0062] Of course, when the sheet 20 passes through a plurality of rolling rollers 123 , its thickness can be further reduced, thereby obtaining a pole piece 30 with a thinner and more uniform thickness.

[0063] In addition, other traction rollers may be provided between the extruding device 110 and the rolling device 120 in the device 100 so that the sheet material 20 can enter the rolling device 120 from the extruding device 110 under the traction of the other traction rollers.

[0064] Figure 3 As an example, a first thinning roller 121, a second thinning roller 122, and three other rolling rollers 123 are shown, and the three rolling rollers 123 are arranged in parallel, and the sheet 20 passes through two adjacent rolling rollers 123 in sequence. It can be understood that in the rolling device 120, the first thinning roller 121 and the second thinning roller 122 can "roughly reduce" the thickness of the sheet 20, and the other three rolling rollers can "finely reduce" the thickness of the sheet 20 after the "rough reduction".

[0065] As an example, the following, combined Figures 3 to 8 , respectively describe Figure 3 The specific structures of the extruding device 110, the rolling device 120 and the tension detection mechanism 130 are shown in FIG.

[0066] In some embodiments, Figure 3 As shown, the extrusion device 110 includes a feeding mechanism 111 and an extrusion die head 112 connected to the feeding mechanism 111 . The feeding mechanism 111 is used to transfer the material 10 to the extrusion die head 112 , and the extrusion die head 112 is used to extrude the material 10 to form a sheet 20 .

[0067] The feeding mechanism 111 transfers the material 10 to the extrusion die 112 , and the extrusion die 112 extrude the material 10 to form a sheet 20 . In this way, the sheet 20 can be formed smoothly through feeding and extruding.

[0068] For example, Figure 4 As shown, the feeding mechanism 111 includes a base 1111, and a motor 1112 and a screw structure 1113 arranged on the base 1111, and the motor 1112 is used to drive the screw structure 1113 to rotate. The feeding mechanism 111 can be, for example, a single screw structure, a double screw structure, or a multi-screw structure. The use of the screw structure 1113 to achieve feeding has high feeding efficiency and feeding stability, and because the feeding speed is positively correlated with the screw speed, it has good adjustability. In the embodiment of the present application, the screw structure 1113 is taken as a single screw structure for illustration.

[0069] The screw structure 1113 delivers the material 10 to the extrusion die 112 by rotating, and the rotation speed of the screw structure 1113 affects the extrusion speed of the extrusion die 112. The faster the rotation speed of the screw structure 1113, the faster the feeding speed of the screw structure 1113, and the faster the extrusion speed of the extrusion die 112; correspondingly, the slower the rotation speed of the screw structure 1113, the slower the feeding speed of the screw structure 1113, and the slower the extrusion speed of the extrusion die 112.

[0070] In some embodiments, for example, Figure 5 and Figure 6 As shown, the extrusion die head 112 includes an inlet 1121 connected to the feeding mechanism 111 , an outlet 1122 for outputting the sheet material 20 , and a flow channel 1123 connecting the inlet 1121 and the outlet 1122 .

[0071] like Figure 5 As shown, the extrusion die 112 includes a first portion 112A and a second portion 112B, the first portion 112A and the second portion 112B are buckled together, and the flow channel 1123 is located between the buckling surfaces of the first portion 112A and the second portion 112B. The feeding mechanism 111 transports the material to the inlet 1121 on the extrusion die 112, and transmits it to the outlet 1122 through the flow channel 1123.

[0072] The first part 112A and the second part 112B may be fixed by, for example, a connector 112C, and the connector 112C and the first part 112A, as well as the connector 112C and the second part 112B may be fixed by, for example, fixing members such as nuts.

[0073] The size of the flow channel 1123 gradually increases from the inlet 1121 to the outlet 1122. Figure 6 As shown, the flow channel 1123 between the inlet 1121 and the outlet 1122 is similar to a hanger shape, and its size gradually increases from the inlet 1121 to the outlet 1122, which can effectively guide the material 10.

[0074] The size of the inlet 1121 can be matched with the size of the outlet of the feeding mechanism 111, and the size of the outlet 1122 can be determined according to the desired size of the sheet 20. For example, the larger the width of the outlet 1122, the greater the thickness of the sheet 20; correspondingly, the smaller the width of the outlet 1122, the smaller the thickness of the sheet 20.

[0075] The extrusion speed of the extrusion device 110 matches the conveying speed of the sheet 20, which can effectively improve the preparation efficiency and quality of the electrode 30. The conveying speed of the sheet 20 can be achieved, for example, by setting the rotation speed of each roller in the device 100. For the set conveying speed of the sheet 20, if the extrusion speed of the extrusion device 110 is too slow and cannot keep up with the conveying speed of the sheet 20, the sheet 20 is prone to over-stretching and breaking; if the extrusion speed of the extrusion device 110 is too fast and the conveying speed of the sheet 20 cannot keep up with the extrusion speed of the extrusion device 110, the material 10 is prone to accumulation in the rolling device 120, resulting in waste of the material 10.

[0076] To this end, in some embodiments, the device 100 further includes a control module (not shown in the figure), which is used to receive the detection result of the tension detection mechanism 130 and adjust the extrusion speed of the extrusion device 110 according to the detection result.

[0077] For example, Figure 7 As shown, at least one roller, such as roller 140, is arranged between the extrusion device 110 and the rolling device 120, wherein the tension detection mechanism 130 is arranged on one side of the roller 140, so that when the sheet material 20 passes through the other side of the roller 140, the tension detection mechanism 130 can detect the tension of the sheet material 20.

[0078] The tension detection mechanism 130 may include a pressure sensor, and the tension of the sheet 20 may be transmitted to the pressure sensor through the roller 140 , so as to be detected by the pressure sensor.

[0079] The tension detection mechanism 130 may, for example, send information about the detected tension of the sheet material 20 to the control module at a certain period or frequency.

[0080] After receiving the detection result fed back by the tension detection mechanism 130, the control module performs closed-loop adjustment on the extrusion speed of the extrusion device 110 according to the detection result, so as to reduce the probability of material 10 accumulation or sheet material 20 being overstretched and broken in the rolling device 120, improve the thickness consistency during the rolling process, improve the product yield, reduce the waste of material 10, and improve the production efficiency, so that the pole piece 30 can be produced stably and continuously.

[0081] For example, when the detection result of the tension detection mechanism 130 is greater than a preset tension value, the extrusion speed of the extrusion device 110 is increased.

[0082] Specifically, when the tension of the sheet 20 detected by the tension detection mechanism 130 is greater than the preset tension value, it means that the conveying speed of the sheet 20 is faster, and the extrusion speed of the extrusion device 110 cannot keep up with the conveying speed of the sheet 20, and the sheet 20 is prone to over-stretching and breaking. The control module controls the extrusion speed of the extrusion device 110 to increase until the tension detected by the tension detection mechanism 130 drops to a preset tension value, thereby reducing the probability of the sheet 20 being over-stretched and breaking.

[0083] For another example, when the detection result of the tension detection mechanism 130 is less than or equal to the tension value, the extrusion speed of the extrusion device 110 is reduced.

[0084] Specifically, when the tension of the sheet material 20 detected by the tension detection mechanism 130 is less than or equal to the preset tension value, it means that the conveying speed of the sheet material 20 is slow and cannot keep up with the extrusion speed of the extrusion device 110, and it is easy for the material 10 to accumulate between the two rollers of the rolling device 120. The control module controls the extrusion speed of the extrusion device 110 to decrease until the tension detected by the tension detection mechanism 130 rises to equal the preset tension value, thereby reducing the probability of accumulation of the material 10 in the rolling device 120.

[0085] It should be understood that the extrusion speed of the extrusion device 110 is associated with the feeding speed of the feeding mechanism 111 in the extrusion device 110. For the extrusion device 110 that uses the above-mentioned screw structure 1113 to feed, the extrusion speed of the extrusion device 110 is positively correlated with the rotation speed of the screw structure 1113. In this case, the screw rotation speed can also be used as a parameter to characterize the extrusion speed. The control module can perform closed-loop regulation on the screw rotation speed according to the detection result of the tension detection mechanism 130.

[0086] In some embodiments, the control module is also used to obtain a preset relationship, wherein the relationship is used to represent the relationship between the extrusion speed and the conveying speed of the sheet 20, and determine a target extrusion speed that matches the conveying speed based on the conveying speed of the sheet 20 and the relationship, thereby adjusting the initial extrusion speed of the extrusion device 110 to the target extrusion speed.

[0087] That is to say, after setting the conveying speed of the sheet material 20, the preset relationship formula for representing the relationship between the extrusion speed of the extrusion device 110 and the conveying speed of the sheet material 20 can be used to calculate the initial extrusion speed of the extrusion device 100 corresponding to the conveying speed, thereby greatly saving the subsequent adjustment time for the extrusion speed and improving production efficiency.

[0088] As described above, for the extrusion device 110 that uses the screw structure 1113 to feed materials, the screw rotation speed can be used as a parameter to characterize the extrusion speed. Therefore, this relationship can also be used to express the relationship between the screw rotation speed and the conveying speed.

[0089] As an example, Figure 8 The schematic diagram of a possible working process 200 of the device 100 for preparing a pole piece is shown. Figure 8 The order of the steps can also be adjusted according to the actual process. Figure 8 The process 200 shown may be executed by the above-mentioned control module, or may be executed by other processing modules independent of the control module.

[0090] like Figure 8 As shown, in step 201, the circuit / gas circuit of the device 100 is checked.

[0091] If a fault is detected, execute step 202; otherwise, execute step 203.

[0092] In step 202, a prompt is given to inspect the circuit / gas circuit of the device 100.

[0093] In step 203, various mechanisms and motors in the device 100 are inspected.

[0094] For example, the motor 1112 of the aforementioned screw structure 1113 , the tension detection mechanism 130 , etc. are inspected.

[0095] If a fault is detected, execute step 202 ; otherwise, execute step 204 .

[0096] In step 204, the device is powered on.

[0097] That is, the device 100 for preparing the electrode piece is powered on to supply electric energy thereto.

[0098] In step 205 , the conveying speed of the sheet 20 is set.

[0099] For example, the rotation speed of each roller may be set so that the conveying speed of the sheet 20 is a desired value.

[0100] In step 206, a tension value is set.

[0101] The tension value is a preset value for determining the adjustment direction of the extrusion speed. When the detection result of the tension detection mechanism 130 is greater than the tension value, the extrusion speed of the extrusion device 110 needs to be increased; when the detection result of the tension detection mechanism 130 is less than or equal to the tension value, the extrusion speed of the extrusion device 110 needs to be reduced.

[0102] In step 207 , the extrusion speed of the extrusion device 110 is set.

[0103] For example, based on the set conveying speed of the sheet material 20 and a relational expression representing the relationship between the extrusion speed and the conveying speed, the initial extrusion speed of the extrusion device 110 can be set to a target extrusion speed corresponding to the conveying speed.

[0104] In step 208 , the extrusion device 110 is controlled to operate.

[0105] For example, for an extrusion device 100 that uses a screw structure 1113 to feed materials, it is necessary to control the motor 1112 of the screw structure 1113 to start, thereby driving the screw structure 1113 to rotate to convey the material 10 .

[0106] In step 209 , the tension detection mechanism 130 is controlled to detect the tension of the sheet material 20 .

[0107] The tension detection mechanism 130 detects the tension of the sheet material 20 transmitted between the extrusion device 100 and the rolling device 120 , and feeds back the detection result to the control module. After receiving the detection result fed back by the tension detection mechanism 130 , the control module executes step 210 .

[0108] In step 210 , the extrusion speed of the extrusion device 110 is fine-tuned.

[0109] For example, the adjustment amount for each fine-tuning can be set, and the tension detection mechanism 130 feeds back the tension detection result based on a predetermined period. The control module increases or decreases the adjustment amount for the extrusion speed based on the detection result received in each period until the detection result fed back by the tension detection mechanism 130 is equal to the tension value set in step 206.

[0110] The above relationship between the extrusion speed and the transmission speed can be obtained by testing and fitting the test data. The fitting can be linear fitting or nonlinear fitting, so as to obtain a relationship between the extrusion speed and the transmission speed.

[0111] For example, the relationship between the extrusion speed and the conveying speed may be expressed as y=kx+b, wherein y is the extrusion speed of the extrusion device 110 , x is the conveying speed of the sheet material 20 , and k and b are fitting parameters.

[0112] Different processes have different extrusion volume requirements, so it is necessary to set a matching extrusion speed. For the conveying speeds of several sheets 20 used for testing, multiple extrusion speeds are constantly tried to obtain a conveying speed that matches each conveying speed and meets predetermined conditions, thereby obtaining multiple sets of data consisting of conveying speeds and extrusion speeds for fitting. The predetermined conditions can, for example, be that the weight of the prepared pole piece 30 meets the requirements, the material 10 wasted in the preparation process meets the requirements, the quality of the prepared pole piece 30 meets the requirements, and so on. Among them, the weight of the pole piece 30 is related to the area, width, etc. of the pole piece 30, and can be converted accordingly.

[0113] For the extrusion device 110 that uses a screw structure 1113 to feed materials, the extrusion speed involved in the relationship can also be replaced by the rotational speed of the screw structure 1113, and the rotational speed of the screw structure 1113 is associated with the operating data of the screw structure 1113, such as frequency, and corresponding conversion can be performed.

[0114] The present application also provides a method 300 for preparing a pole piece 30, which is applied to the above-mentioned device 100 for preparing a pole piece 30, wherein the device 100 comprises an extrusion device 110 and a rolling device 120, wherein the rolling device 120 is disposed downstream of the extrusion device 110. Fig. 9 As shown, method 300 includes part or all of the following steps.

[0115] In step 310 , the extrusion device 110 is controlled to extrude the material 10 into a sheet 20 .

[0116] In step 320 , the rolling device 120 is controlled to roll the sheet material 20 to form the pole piece 30 .

[0117] Wherein, step 310 and step 320 can be performed in parallel, so as to continuously prepare the pole piece 30 .

[0118] In some embodiments, the device 100 also includes a roller 140 and a tension detection mechanism 130. The roller 140 is arranged between the extrusion device 110 and the rolling device 120. The tension detection mechanism 130 is arranged on one side of the roller 140 and is used to detect the tension of the sheet material 20 when the sheet material 20 passes through the other side of the roller 140.

[0119] In some embodiments, the method 300 further includes: receiving a detection result of the tension detection mechanism 130 ; and adjusting an extrusion speed of the extrusion device 110 according to the detection result.

[0120] In some embodiments, the extrusion speed of the extrusion device 110 is adjusted according to the detection result, including: when the detection result of the tension detection mechanism 130 is greater than the preset tension value, increasing the extrusion speed of the extrusion device 110; when the detection result of the tension detection mechanism 130 is less than or equal to the tension value, reducing the extrusion speed of the extrusion device 110.

[0121] In some embodiments, method 300 also includes: obtaining a preset relationship equation, which is used to express the relationship between the extrusion speed and the conveying speed of the sheet 20; determining a target extrusion speed that matches the conveying speed based on the conveying speed of the sheet 20 and the relationship equation; and adjusting the initial extrusion speed of the extrusion device 110 to the target extrusion speed.

[0122] In some embodiments, the extrusion die 112 includes an inlet 1121 connected to the feeding mechanism 111, an outlet 1122 for outputting the sheet 20, and a flow channel 1123 connecting the inlet 1121 and the outlet 1122, and the size of the flow channel 1123 gradually increases from the inlet 1121 to the outlet 1122.

[0123] In some embodiments, the feeding mechanism 111 includes a base 1111, and a motor 1112 and a screw structure 1113 disposed on the base 1111. The motor 1112 is used to drive the screw structure 1113 to rotate. The screw structure 1113 may be a single screw structure, a double screw structure, or a multi-screw structure.

[0124] In some embodiments, the rolling device 120 includes a first thinning roller 121 and a second thinning roller 122 , and the first thinning roller 121 and the second thinning roller 122 are disposed on two sides of the sheet material 20 opposite to each other for thinning the sheet material 20 .

[0125] In some embodiments, the rolling device 120 further includes at least two rolling rollers for rolling the thinned sheet material 20 at least once.

[0126] In some embodiments, the rolling device 120 further includes a feeding device for conveying the material 10 to the extruding device 110 .

[0127] It can be understood that the specific details of the method 300 can refer to the above description of the device 100, and for the sake of simplicity, they are not repeated here.

[0128] The present application also provides a battery, which includes an electrode assembly, and the electrode assembly includes a pole piece 30. The pole piece 30 is prepared by using the device 100 for preparing a pole piece described in any of the above embodiments, or is prepared by using the method for preparing a pole piece described in any of the above embodiments.

[0129] The present application also provides an electrical device, comprising the battery described in any one of the above embodiments, wherein the battery is used to provide power for the electrical device.

[0130] As can be seen from the above description, in the embodiment of the present application, the device 100 for preparing the pole piece includes an extrusion device 110, a rolling device 120, and a tension detection mechanism 130 connected between the extrusion device 110 and the rolling device 120. The extrusion device 110 includes a screw structure 1113 and an extrusion die 112. In the process of preparing the pole piece 30, the material 10 is fed into the screw structure 1113, and the screw structure 1113 conveys the material 10 to the extrusion die 112 at a certain rotation speed. The extrusion die 112 extrude a thick sheet material 20 with a certain thickness according to a fixed shape. The sheet material 20 is rolled, i.e., calendered, in the rolling device 120 to form the pole piece 30. Because the extrusion device 110 pre-extrudes the material 10 into the sheet 20 before the material 10 enters the rolling device 120, and then rolls the sheet 20, the material 10 has a regular shape and relatively uniform thickness before entering the rolling device 120, which greatly improves the consistency of the thickness of the electrode 30 formed after rolling, and makes the thickness of the final electrode 30 more uniform.

[0131] At the same time, a tension detection mechanism 130 is added between the extrusion die 112 and the roller pressing device 120 to detect the tension of the sheet 20 extruded from the extrusion die 112 to the roller pressing device 120 in real time. By comparing the tension detection value with the preset tension value, when the difference between the two reaches a certain level, the control module adjusts the rotation speed of the screw structure 1113 so that the tension of the sheet 20 extruded from the extrusion die 112 during the process of entering the roller pressing device 120 remains stable. In this way, the rotation speed of the screw structure 1113 is adjusted online in real time by means of tension closed-loop control, which improves the consistency of the sheet 20 entering the roller, solves the problem of material 10 accumulation in the roller pressing device 120, reduces the waste of material 10, and makes the sheet 20 uniformly rolled when passing through the roller pressing device 120, without the need to adjust the roller gap size and pressure between the rollers in real time, thereby improving the preparation quality and preparation efficiency of the pole piece 30.

[0132] It should be noted that, under the premise of no conflict, the various embodiments described in this application and / or the technical features in each embodiment can be arbitrarily combined with each other, and the technical solution obtained after the combination should also fall within the protection scope of this application.

[0133] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0134] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0135] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

Claims

1. A device for preparing a pole piece, characterized in that: The device comprises: An extruder, used for extruding the material into sheets; and The rolling device is arranged downstream of the extruding device and is used for rolling the sheet material to form a pole piece.

2. The device according to claim 1, characterized in that The extrusion device comprises a feeding mechanism and an extrusion die head connected to the feeding mechanism, wherein the feeding mechanism is used to transfer the material to the extrusion die head, and the extrusion die head is used to extrude the material to form the sheet material.

3. The device according to claim 2, characterized in that The extrusion die head includes an inlet connected to the feeding mechanism, an outlet for outputting the sheet material, and a flow channel connecting the inlet and the outlet, and the size of the flow channel gradually increases from the inlet to the outlet.

4. The device according to claim 2 or 3, characterized in that The feeding mechanism includes a base, and a motor and a screw structure arranged on the base. The screw structure includes a single-screw structure, a double-screw structure, or a multi-screw structure. The motor is used to drive the screw structure to rotate.

5. The device according to any one of claims 1 to 4, characterized in that The device also includes: A roller is arranged between the extruding device and the rolling device; and The tension detection mechanism is arranged on one side of the passing roller and is used for detecting the tension of the sheet when the sheet passes through the other side of the passing roller.

6. The device according to claim 5, characterized in that The device also includes: The control module is used to receive the detection result of the tension detection mechanism and adjust the extrusion speed of the extrusion device according to the detection result.

7. The device according to claim 6, characterized in that The control module is specifically used for: When the detection result of the tension detection mechanism is greater than a preset tension value, increasing the extrusion speed of the extrusion device; When the detection result of the tension detection mechanism is less than or equal to the tension value, the extrusion speed of the extrusion device is reduced.

8. The device according to claim 6 or 7, characterized in that The control module is also used to: Obtaining a preset relationship expression, wherein the relationship expression is used to express the relationship between the extrusion speed and the conveying speed of the sheet material; According to the conveying speed of the sheet material and the relationship, determining a target extrusion speed matching the conveying speed; The initial extrusion speed of the extrusion device is adjusted to the target extrusion speed.

9. The device according to any one of claims 1 to 8, characterized in that The rolling device comprises a first thinning roller and a second thinning roller, wherein the first thinning roller and the second thinning roller are arranged oppositely on two sides of the sheet material and are used for thinning the sheet material.

10. The device according to claim 9, characterized in that The rolling device also includes at least two rolling rollers, which are used to roll the thinned sheet material at least once.

11. The device according to any one of claims 1 to 10, characterized in that The roller pressing device also includes a feeding device for conveying the material to the extruding device.

12. A method for preparing a pole piece, characterized in that: A device for preparing a pole piece, the device comprising an extrusion device and a rolling device, the rolling device being arranged downstream of the extrusion device, the method comprising: Controlling the extrusion device to extrude the material into sheets; The rolling device is controlled to roll the sheet material to form a pole piece.

13. The method according to claim 12, characterized in that The device also includes a roller and a tension detection mechanism. The roller is arranged between the extrusion device and the rolling device. The tension detection mechanism is arranged on one side of the roller and is used to detect the tension of the sheet when the sheet passes through the other side of the roller.

14. The method according to claim 13, characterized in that The method further comprises: receiving a detection result of the tension detection mechanism; The extrusion speed of the extrusion device is adjusted according to the detection result.

15. The method according to claim 14, characterized in that The step of adjusting the extrusion speed of the extrusion device according to the detection result comprises: When the detection result of the tension detection mechanism is greater than a preset tension value, increasing the extrusion speed of the extrusion device; When the detection result of the tension detection mechanism is less than or equal to the tension value, the extrusion speed of the extrusion device is reduced.

16. The method according to claim 14 or 15, characterized in that The method further comprises: Obtaining a preset relationship expression, wherein the relationship expression is used to express the relationship between the extrusion speed and the conveying speed of the sheet material; According to the conveying speed of the sheet material and the relationship, determining a target extrusion speed matching the conveying speed; The initial extrusion speed of the extrusion device is adjusted to the target extrusion speed.

17. The method according to any one of claims 12 to 16, characterized in that The extrusion device comprises a feeding mechanism and an extrusion die head connected to the feeding mechanism, wherein the feeding mechanism is used to transfer the material to the extrusion die head, and the extrusion die head is used to extrude the material to form the sheet material.

18. The device according to claim 17, characterized in that The extrusion die head includes an inlet connected to the feeding mechanism, an outlet for outputting the sheet material, and a flow channel connecting the inlet and the outlet, and the size of the flow channel gradually increases from the inlet to the outlet.

19. The method according to claim 17 or 18, characterized in that The feeding mechanism includes a base, and a motor and a screw structure arranged on the base. The screw structure includes a single-screw structure, a double-screw structure, or a multi-screw structure. The motor is used to drive the screw structure to rotate.

20. The method according to any one of claims 12 to 19, characterized in that The rolling device comprises a first thinning roller and a second thinning roller, wherein the first thinning roller and the second thinning roller are arranged oppositely on two sides of the sheet material and are used for thinning the sheet material.

21. The method according to claim 20, characterized in that The rolling device also includes at least two rolling rollers, which are used to roll the thinned sheet material at least once.

22. The method according to any one of claims 12 to 21, characterized in that The roller pressing device also includes a feeding device for conveying the material to the extruding device.

23. A battery, characterized in that: It comprises an electrode assembly, wherein the electrode assembly comprises a pole piece, and the pole piece is prepared by using the apparatus for preparing a pole piece as described in any one of claims 1 to 11, or is prepared by using the method for preparing a pole piece as described in any one of claims 12 to 22.

24. An electrical device, characterized in that: The battery according to claim 23 is used to provide power for the electrical device.

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