CN210792185U

CN210792185U - Pole piece forming device

Info

Publication number: CN210792185U
Application number: CN201920835764.0U
Authority: CN
Inventors: 邹建琨; 李世松; 李克强; 虞永生
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2019-06-04
Filing date: 2019-06-04
Publication date: 2020-06-19
Anticipated expiration: 2029-06-04

Abstract

In order to achieve the above object, the utility model provides a pole piece forming device, it includes unwinding mechanism, tension mechanism and winding mechanism. Unwinding mechanism is used for setting up the pole piece, and winding mechanism is used for drawing the pole piece and passes stretching mechanism and rolling pole piece. The stretching mechanisms are multiple and are sequentially arranged along the tape moving direction of the pole piece. Each stretching mechanism comprises a first compression roller assembly and a second compression roller assembly, and the pole pieces are arranged to penetrate through the space between the first compression roller assembly and the second compression roller assembly. The first press roll component of each stretching mechanism is multiple and arranged along the transverse direction.

Description

Pole piece forming device

Technical Field

The utility model relates to a battery production field especially relates to a pole piece forming device.

Background

At present, the requirement of each large automobile factory on the battery of the electric automobile is higher and higher, and the important point is that the energy density of the battery is higher, the battery capacity is higher under the same weight when the energy density of the battery is higher, and the mileage which can be driven by the single charging of the automobile is correspondingly increased.

In the production process of the battery pole piece, the pole piece is usually rolled to improve the compaction density of the pole piece, and further improve the energy density of the battery. Referring to fig. 1, the conventional pole piece S includes a base material S1 and a coating layer S2 disposed on the base material S1, and the base material S1 has an exposed blank area S11 and a coated area S12 covered with the coating layer S2. However, during the rolling process of the pole piece, the blank area S11 of the substrate S1 is not pressed and does not stretch, and the coated area S12 of the substrate S1 produces rolling elongation, so that the elongation of different areas of the substrate S1 is different, and the blank area S11 of the substrate S1 is likely to wrinkle, and the rolling of the pole piece S is uneven.

SUMMERY OF THE UTILITY MODEL

In view of the problem that exists among the background art, the utility model aims to provide a pole piece forming device, its uniformity that can guarantee the substrate extension avoids the blank of substrate to crumple.

First compression roller subassembly includes first compression roller and first driver, and first driver is connected in first compression roller and can drive first compression roller and be close to or keep away from second compression roller subassembly.

The stretching mechanism further comprises a first guide member extending in the transverse direction, and the first drivers of the plurality of first press roller assemblies are slidably connected to the first guide member.

The first guide member includes a support and a guide rail fixed to the support and extending in a lateral direction. The first press roller assembly further comprises a sliding block and a support, the sliding block is in sliding fit with the guide rail, and the support is fixed on the sliding block. The first driver is fixed to the bracket.

The number of the first guide members is two, and each first guide member is connected to the first drivers of the plurality of first press roller assemblies.

The first press roller comprises a roller body and a plastic layer coated on the roller body.

The pole piece forming device further comprises a heating mechanism, and the heating mechanism is arranged on a tape walking path of the pole piece and can heat the pole piece. The heating mechanism is located upstream of the at least one stretching mechanism in the direction of travel of the pole pieces.

The heating mechanism comprises a second guide member and a plurality of heaters, the second guide member extends along the transverse direction, and the heaters are connected to the second guide member in a sliding mode.

The heating mechanism further comprises a third guide member, and the third guide member is connected to the second guide member and can drive the second guide member to be close to or far away from the pole piece.

The second compression roller assembly comprises a second compression roller and a second driver, and the second driver is connected to the second compression roller.

The utility model has the advantages as follows: this application can stretch the blank area of pole piece, can make the holistic percentage elongation of substrate unanimous or close to avoid the blank area of substrate to crumple or the perk. In addition, the forming of pole pieces of various specifications can be realized, and the universality is better.

Drawings

FIG. 1 is a schematic view of a pole piece.

Fig. 2 is a schematic diagram of a pole piece forming device according to the present invention.

Fig. 3 is a schematic view of the drawing mechanism of the pole piece forming device according to the present invention.

Fig. 4 is another schematic diagram of the stretching mechanism of the pole piece forming device according to the present invention.

Fig. 5 is a schematic view of a heating mechanism of the pole piece forming device according to the present invention.

Fig. 6 is another schematic view of the heating mechanism of the pole piece forming device according to the present invention.

Fig. 7 is another schematic view of the heating mechanism of the pole piece forming device according to the present invention.

Wherein the reference numerals are as follows:

1 unwinding mechanism

2 stretching mechanism

21 first press roll assembly

211 first press roll

211a roller body

211b plastic layer

212 first driver

213 slide block

214 support

215 locking screw

216 drive assembly

22 second press roll assembly

221 second press roll

222 second driver

23 first guide member

231 support

232 guide rail

3 winding mechanism

4 heating mechanism

41 second guide member

42 heater

43 third guide member

431 base

432 spiral element

433 sliding rod

44 adapter component

441 fixing plate

442 locking screw

5 tension detection mechanism

6-roller pressing mechanism

61 third press roll

62 fourth press roll

7 tension adjusting mechanism

8 driving roller

S pole piece

S1 base material

S11 blank area

S12 coating area

S2 coating

In the X transverse direction

Y longitudinal direction

In the Z vertical direction

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

In the description of the present application, unless explicitly stated or limited otherwise, the terms "first", "second", "third", "fourth" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means more than two (including two); the term "coupled", unless otherwise specified or indicated, is to be construed broadly, e.g., "coupled" may be a fixed or removable connection or a connection that is either integral or electrical or signal; "connected" may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In the description of the present application, it should be understood that the terms "upper" and "lower" used in the description of the embodiments of the present application are used in a descriptive sense only and not for purposes of limitation. The present application is described in further detail below with reference to specific embodiments and with reference to the attached drawings.

The pole piece forming device can be used for producing the pole piece S of the battery. Specifically, referring to fig. 1, the pole piece S includes a base material S1 and a coating layer S2, the base material S1 includes a blank area S11 and a coating area S12 covered by the coating layer S2, and the blank area S11 and the coating area S12 are alternately arranged in the transverse direction X. The substrate S1 may be a metal foil and the coating S2 may include an active substance. When the pole piece S is a negative pole piece, the active substance comprises graphite or silicon; when the pole piece S is a positive pole piece, the active material comprises a ternary material, lithium manganate or lithium iron phosphate.

In the production process of the pole piece S, the pole piece S is usually wound into a roll. In addition, the transverse direction X is parallel to the width direction of the pole piece S, preferably, the transverse direction X is parallel to the horizontal plane. The upstream and downstream are both in terms of the direction of travel of the sheet S.

The pole piece forming device can be used for stretching the blank area S11 of the pole piece S. Specifically, the pole piece forming device of this application includes unwinding mechanism 1, tension mechanism 2 and winding mechanism 3.

Unwinding mechanism 1 is used for setting up pole piece S. Specifically, the unwinding mechanism 1 may include an unwinding roller, and when the blank area S11 of the pole piece S needs to be stretched, the roll of the pole piece S may be set on the unwinding roller.

The winding mechanism 3 is used for drawing the pole piece S to penetrate through the stretching mechanism 2 and winding the pole piece S. The winding mechanism 3 may include a winding roller, which is a driving roller.

The drawing mechanisms 2 are plural and are sequentially arranged along the tape running direction of the pole piece S. Each stretching mechanism 2 includes a first roller assembly 21 and a second roller assembly 22, and the pole piece S is disposed to pass between the first roller assembly 21 and the second roller assembly 22. The first roll assemblies 21 of each stretching mechanism 2 are plural and arranged in the transverse direction X. Specifically, the first roll assembly 21 includes a first roll wheel 211, and the second roll assembly 22 includes a second roll wheel 221.

When the blank area S11 of the pole piece S needs to be stretched, the pole piece S is fixed to the unwinding mechanism 1, then the free end of the pole piece S is pulled to sequentially pass through the stretching mechanisms 2, and finally the free end of the pole piece S is fixed to the winding mechanism 3. The pole pieces S should pass through between the first roller 211 and the second roller 221, and each blank area S11 is located between the second roller 221 and a corresponding one of the first rollers 211.

After the threading is finished, the plurality of first pressing roller assemblies 21 are moved, so that the second roller 221 and the first roller 211 are pressed against the blank area S11 of the pole piece S. Then, the unwinding mechanism 1, the second pressing roller assembly 22 and the winding mechanism 3 operate to drive the pole piece S to be unwound.

The linear speeds of the second rollers 221 of the second press roller assemblies 22 of the plurality of stretching mechanisms 2 are set to be sequentially increased along the tape running direction of the pole piece S.

In the process of the tape-moving of the pole piece S, the roller surface of the second roller 221 should be in close contact with the blank area S11 without slipping, so the linear speed of the roller surface of the second roller 221 is the tape-moving speed of the blank area S11. The coating S2 is not rolled by the first roller 211 and the second roller 221.

When the pole piece S enters the stretching mechanism 2, the blank area S11 of the substrate S1 is stretched by force. Specifically, referring to fig. 2, when the substrate S1 enters the first stretching mechanism 2 (i.e., the stretching mechanism 2 closest to the unwinding mechanism 1), the blank space S11 has a speed V₁In which V is₁The linear velocity of the roll surface of the second roll 221 of the first stretching mechanism 2. When the base material S1 enters the second stretching mechanism 2, the blank area S11 has a speed V₂，V₂The linear velocity of the roll surface of the second roller 221 of the second stretching mechanism 2. Due to V₂>V₁The blank space S11 is subjected to tangential tension and thus stretched. Similarly, when the base material S1 enters the third stretching mechanism 2, the blank area S11 has a speed V₃，V₃The linear velocity of the roll surface of the second roll 221 of the third stretching mechanism 2; due to V₃>V₂The blank space S11 is subjected to tangential tension and thus stretched.

The elongation of the blank area S11 is determined by the speed difference between the stretching units 2 (e.g., V)₃-V₁) Therefore, the pole piece forming device of the utility model can ensure that the blank area S11 extends with constant elongation; when the blank region S11 reaches the target elongation, the blank region S11 is not subjected to the continuous action of the tangential tension, and therefore, even if the blank region S11 is defective during the elongation, no excessive deterioration occurs,thereby reducing the risk of belt breakage.

The number of the drawing mechanisms 2 is preferably three or more, so that the drawing process of the blank area S11 can be divided into multiple stages, the tension in each drawing process can be reduced, the stress concentration can be avoided, and the blank area S11 can be prevented from being broken.

In the production process of the battery pole piece S, in order to improve the production efficiency, a plurality of coating layers S2 are usually coated on the base material S1. Referring to fig. 1, the blank space S11 of the substrate S1 may be plural. Of course, in order to roll the plurality of blank areas S11 at the same time, the first roll assembly 21 is also provided in plurality. Preferably, the first roller assembly 21 may have a larger number, for example 5-7. Thus, when the number of blank areas S11 of the pole piece S is changed, it is only necessary to change the number of first roll assemblies 21 that are operated.

In addition, when the width of the coating layer S2 of the pole piece S is changed, the requirement of the pole piece S can also be met by changing the spacing between the adjacent first pressing roller assemblies 21.

In summary, the present application can stretch the blank area S11 of the pole piece S, so that the elongation of the entire substrate S1 is consistent or close to each other, thereby preventing the blank area S11 of the substrate S1 from wrinkling or tilting. In addition, this application sets up first compression roller assembly 21 to a plurality of to realize the shaping of the pole piece S of multiple specification, have better commonality.

Referring to fig. 2, the pole piece forming device further comprises a rolling mechanism 6, and the rolling mechanism 6 is arranged at the upstream or the downstream of the stretching mechanism 2. The roller pressing mechanism 6 includes a third roller 61 and a fourth roller 62 which are oppositely disposed. The pole piece S is arranged to pass through between the third pressing roller 61 and the fourth pressing roller 62 and is pressed. The third pressing roller 61 and the fourth pressing roller 62 are both equal diameter rollers, and when the pole piece S passes between the third pressing roller 61 and the fourth pressing roller 62, the third pressing roller 61 and the fourth pressing roller 62 press the coating area S12 and the coating S2.

The third press roller 61 may be connected to a cylinder to be close to or far from the fourth press roller 62 by the driving of the cylinder. By controlling the interval between the third pressing roller 61 and the fourth pressing roller 62, it is possible to change the roller pressure between the third pressing roller 61 and the fourth pressing roller 62 and to adjust the thickness of the coating layer S2 and the coating zone S12. The fourth pressing roller 62 may be connected to a motor, and the motor drives the fourth pressing roller 62 to rotate, so as to drive the pole piece S to move.

In the pole piece forming device of the present application, the third pressing roller 61 and the fourth pressing roller 62 can roll the coating area S12 of the substrate S1, and the plurality of stretching mechanisms 2 can stretch the blank area S11 of the substrate S1 by using a differential speed, so that the rolling process of the rolling mechanism 6 and the stretching process of the stretching mechanisms 2 can make the entire extensibility of the substrate S1 consistent or close, thereby avoiding the blank area S11 of the substrate S1 from being wrinkled or tilted. Meanwhile, the pole piece forming device integrates the rolling process of the coating area S12 and the coating layer S2 and the stretching process of the blank area S11, and is beneficial to improving the production efficiency.

The pole piece forming device further comprises a tension detection mechanism 5 and a tension adjusting mechanism 7. The tension detection mechanism 5 is arranged between the unwinding mechanism 1 and the stretching mechanism 2. Tension detection mechanism 5 includes driving roller, sensor and mounting bracket, and the driving roller is connected in the mounting bracket and is supplied pole piece S to pass rotatoryly, and the sensor sets up the tension on mounting bracket and real-time detection pole piece S.

The tension adjusting mechanisms 7 are two and located respectively upstream and downstream of the plurality of stretching mechanisms 2. Each tension adjusting mechanism 7 comprises a transmission roller and a swing rod, the transmission roller is connected to the swing rod and is used for the pole piece S to pass through, and the swing rod is connected with the control system and can drive the transmission roller to swing. The tension detection mechanism 5 can monitor the tension of the pole piece S in real time and feed the tension back to the control system; the control system controls the swing rod to swing according to the tension information so as to adjust the tension of the pole piece S and ensure the tension of the pole piece S to be stable; during the speed increasing and reducing of the equipment, the tension adjusting mechanism 7 can provide tension buffering effect for the pole piece S, and the fluctuation range of the tension is reduced.

The pole piece forming device further comprises a plurality of driving rollers 8 which are arranged on a tape walking path of the pole piece S so as to support the pole piece S and adjust the tape walking direction of the pole piece S.

Referring to fig. 3, the first press roller assembly 21 further includes a first driver 212, and the first driver 212 is connected to the first press roller 211 and can drive the first press roller 211 to approach or separate from the second press roller assembly 22. The first driver 212 may be an air cylinder and drives the first pressing roller 211 to move linearly. Of course, the first press roller assembly 21 may further include a driving assembly 216, and the driving assembly 216 connects the first press roller 211 and the first driver 212. The driving assembly 216 may include a guide, a slider, etc. to guide the first pressing roller 211 to move linearly.

In the present application, each first pressing roller 211 is driven by a corresponding one of the first drivers 212, that is, the roller pressure between each first pressing roller 211 and the second pressing roller 221 can be precisely controlled, so as to ensure the uniformity of the force applied to the plurality of blank areas S11 of the pole piece S.

The second press roll assembly 22 further comprises a second driver 222, the second driver 222 being connected to the second press roll 221. The second driver 222 may be a motor and drives the second pressing roller 221 to rotate. In other words, the second pressing roller 221 is a driving roller, the first pressing roller 211 is a driven roller, and the tape running speed of the pole piece S is equal to the linear speed of the roller surface of the second pressing roller 221. In the present application, the second pressing roller 221 is a driving roller and simultaneously presses the blank regions S11, so as to ensure the consistency of the tape-feeding speed of the blank regions S11 and reduce the risk of wrinkling of the blank regions S11.

The second driver 222 is preferably a high-precision motor, which controls the rotation precision to 0.1%, and the speed ratio control precision range is realized to be less than 0.2%. The second press roll 221 is a solid steel roll.

Referring to fig. 3 and 4, the stretching mechanism 2 further includes a first guide member 23 extending in the transverse direction X, and the first drivers 212 of the plurality of first press roller assemblies 21 are slidably connected to the first guide member 23. When the width of the coating S2 of the pole piece S is changed, the first pressing roller assembly 21 may be slid along the first guide member 23 to adjust the interval between the adjacent first pressing rollers 211, thereby accommodating the change in the specifications of the pole piece S.

Specifically, the first guide member 23 includes a support 231 and a rail 232, the support 231 may be fixed to the frame, and the rail 232 is fixed to the support 231 and extends in the transverse direction X. The guide rail may be formed integrally with the supporter 231 or may be coupled by a fastener.

The first press roller assembly 21 further includes a slider 213 and a bracket 214, the slider 213 is slidably engaged with the guide rail 232, and the bracket 214 is fixed to the slider 213. The first driver 212 is fixed to the bracket 214.

When the width of the coating S2 of the pole piece S is changed, the bracket 214 may be manually pushed to slide the slider 213 along the guide rail 232, thereby adjusting the spacing between the first pressing rollers 211.

The number of the first guide members 23 is two, and each of the first guide members 23 is connected to the first driver 212 of the plurality of first press roller assemblies 21. The two first guide members 23 can make the first pressing roller 211 more stable while improving the overall strength of the stretching mechanism 2.

The bracket 214 may include two support walls perpendicular to each other, and a slider 213 is fixed to each of the two support walls. The two first guide means 23 cooperate with the slide blocks 213 on the two support walls, respectively.

The first press roller assembly 21 may further include a locking screw 215, and the locking screw 215 passes through the supporter 231 and is screw-coupled with the supporter 231. When the first pressing roller 211 is moved to the set position, it is pressed against the slider 213 by rotating the locking screw 215. This can prevent the slider 213 from shaking during operation, and improve the stability of the first platen assembly 21.

The first pressing roller 211 includes a roller body 211a and a plastic layer 211b coated on the roller body 211 a. The plastic layer 211b is soft and easily deformed. Since the pole piece S is thin (the pole piece S is generally 100 μm to 200 μm, and the substrate S1 is generally 6 μm to 20 μm), the pressure required for plastic deformation of the pole piece S is greater than the force required for elastic deformation of the plastic layer 211b, and therefore, the roller pressure applied by the first pressing roller 211 and the second pressing roller 221 to the blank area S11 is not enough to thin the blank area S11, and only the blank area S11 and the second pressing roller 221 are in close contact without relative sliding. In summary, in the present application, the blank section S11 is extended by the speed difference of the blank section S11 between the plurality of stretching mechanisms 2, rather than the roller pressure between the first pressing roller 211 and the second pressing roller 221.

Referring to fig. 2 and 5, the pole piece forming apparatus of the present application further includes a heating mechanism 4, and the heating mechanism 4 is disposed in a tape running path of the pole piece S and is capable of heating the pole piece S. The heating means 4 is located upstream of the at least one drawing means 2 in the direction of travel of the sheet S. Preferably, the heating mechanism 4 of the present application is used to heat the blank area S11 of the pole piece S.

In the present application, the heating mechanism 4 may heat the blank region S11, and reduce the yield stress of the blank region S11, making it easier to extend. That is, the present application can reduce the difficulty of stretching the blank space S11 and increase the elongation of the blank space S11 by providing the heating means 4.

The heating mechanism 4 may be the same in number as the stretching mechanism 2, and the heating mechanism 4 and the stretching mechanism 2 are alternately arranged in the tape running direction of the pole piece S.

Preferably, the heating means 4 are one and located between the two stretching means 2 closest to the winding means 3. When the pole piece S is transported between the stretching mechanisms 2, the blank area S11 is gradually stretched, and the closer to the winding mechanism 3, the greater the elongation of the blank area S11; as the elongation increases, the risk of breakage of the blank space S11 increases. The blank space S11 has the largest elongation rate and the highest risk of breakage of the blank space S11 between the two stretching mechanisms 2 closest to the winding mechanism 3, and therefore, it is preferable to provide the heating mechanism 4 between the two stretching mechanisms 2 closest to the winding mechanism 3.

Referring to fig. 5, the heating mechanism 4 includes a second guide member 41 and a plurality of heaters 42, the second guide member 41 extends in the transverse direction X, and the heaters 42 are slidably coupled to the second guide member 41. The pole piece S may pass through the underside of the heater 42 with each blank area S11 of the pole piece S opposing a corresponding one of the heaters 42. The heater is plate-shaped and heats the blank space S11 by means of heat radiation, heat conduction, magnetic induction heating, or the like.

When the width of the coating S2 of the pole piece S is changed, the heaters 42 may be slid along the second guide member 41 to adjust the spacing between adjacent heaters 42 to accommodate the change in the gauge of the pole piece S.

The heating mechanism 4 further includes a plurality of adapter members 44, each adapter member 44 including a fixing plate 441 and a locking screw 442, the fixing plate 441 being slidably coupled to the second guide member 41, and the locking screw 442 being threadedly coupled to the fixing plate 441 and being insertable into the second guide member 41. Each heater 42 is fixed to the fixing plate 441 corresponding to one of the adaptor members 44.

Referring to fig. 6, the second guide member 41 may be provided with a blind hole, and a locking screw 442 is threadedly coupled to the fixing plate 441 and inserted into the blind hole of the second guide member 41, thereby fixing the fixing plate 441 to the second guide member 41, preventing the fixing plate 441 and the heater 42 from fluctuating in the lateral direction X.

When it is necessary to adjust the position of the heater 42, the locking screw 442 is rotated to disengage the locking screw 442 from the second guide member 41, and then the fixing plate 441 is manually slid.

The temperature of the blank space S11 was controlled to 100 ℃ to 200 ℃. The high temperature can produce the potential safety hazard, leads to the microstructure of blank area S11 to take place obvious change, is unfavorable for the subsequent die cutting process and the winding process of pole piece S. If the temperature is too low, the increase of the elongation of the blank area S11 is small, the reduction of the strength of the blank area S11 is limited, and the effect of improving the broken tape of the pole piece S is not obvious. The heater 42 heats the blank space S11 by heat radiation, etc., and the distance between the heater 42 and the blank space S11 directly affects the temperature of the blank space S11. In order to adjust the distance between the heater 42 and the blank space S11, the heating mechanism 4 of the present application preferably further includes a third guide member 43, and the third guide member 43 is connected to the second guide member 41 and can drive the second guide member 41 to approach or separate from the pole piece S. By moving the second guide member 41, the interval between the heater 42 and the blank space S11 can be adjusted, and the temperature of the blank space S11 can be controlled within a suitable range.

Referring to fig. 7, the third guide member 43 includes a base 431, a screw 432 and a rod 433, the screw 432 extends in the vertical direction Z and is rotatably connected to the base 431, and the rod 433 is screw-connected to the screw 432. One end of the screw member 432 is connected to the base 431 through a bearing, and the other end is provided with a handle; by rotating the handle, the screw 432 can be rotated.

Screw 432 has a threaded region, and a sliding rod 433 is threadedly engaged with screw 432; when the screw 432 rotates, the slide bar 433 moves up and down in the vertical direction Z.

The second guide member 41 is connected to the slide bar 433. The second guide member 41 may include a guide shaft and end caps fixed to both ends of the guide shaft, and the end caps may be fixed to the slide bar 433.

When the distance between the heater 42 and the blank space S11 needs to be adjusted, the spiral part 432 is rotated, and the spiral part 432 drives the heater 42 to move through the sliding rod 433 and the second guide member 41.

Preferably, a driving roller 8 is disposed on a side of the pole piece S away from the heater 42, and the driving roller 8 can support the pole piece S to prevent the pole piece S from collapsing.

Claims

1. A pole piece forming device is characterized by comprising an unreeling mechanism (1), a stretching mechanism (2) and a reeling mechanism (3);

the unwinding mechanism (1) is used for arranging a pole piece (S), and the winding mechanism (3) is used for drawing the pole piece (S) to penetrate through the stretching mechanism (2) and winding the pole piece (S);

the stretching mechanisms (2) are multiple and are sequentially arranged along the tape moving direction of the pole piece (S);

each stretching mechanism (2) comprises a first pressing roller assembly (21) and a second pressing roller assembly (22), and the pole piece (S) is arranged to penetrate through between the first pressing roller assembly (21) and the second pressing roller assembly (22);

the first press roll assemblies (21) of each stretching mechanism (2) are multiple and arranged along the transverse direction (X).

2. The pole piece forming device according to claim 1, wherein the first pressing roller assembly (21) comprises a first pressing roller (211) and a first driver (212), the first driver (212) is connected to the first pressing roller (211) and can drive the first pressing roller (211) to be close to or far away from the second pressing roller assembly (22).

3. Pole piece forming device according to claim 2, characterized in that the stretching means (2) further comprise a first guide member (23) extending in the transversal direction (X), the first actuators (212) of the plurality of first pressure roller assemblies (21) being slidingly connected to the first guide member (23).

4. The pole piece forming device of claim 3,

the first guide member (23) comprises a support (231) and a guide rail (232), the guide rail (232) being fixed to the support (231) and extending in the transverse direction (X);

the first press roller assembly (21) further comprises a sliding block (213) and a bracket (214), the sliding block (213) is in sliding fit with the guide rail (232), and the bracket (214) is fixed on the sliding block (213);

the first driver (212) is fixed to the bracket (214).

5. The pole piece forming device according to claim 3, wherein the number of the first guide members (23) is two, and each of the first guide members (23) is connected to the first driver (212) of the plurality of first press roller assemblies (21).

6. The pole piece forming device according to claim 2, wherein the first pressing roller (211) comprises a roller body (211a) and a plastic layer (211b) coated on the roller body (211 a).

7. The pole piece forming device of any one of claims 1 to 6,

the pole piece forming device also comprises a heating mechanism (4), and the heating mechanism (4) is arranged on a tape travelling path of the pole piece (S) and can heat the pole piece (S);

the heating mechanism (4) is located upstream of the at least one stretching mechanism (2) in the direction of travel of the pole pieces (S).

8. Pole piece forming device according to claim 7, characterized in that the heating means (4) comprise a second guide member (41) and a heater (42), the second guide member (41) extending in the transverse direction (X), the heater (42) being in plurality and being slidably connected to the second guide member (41).

9. The pole piece forming device of claim 8,

the heating mechanism (4) further comprises a third guide member (43), and the third guide member (43) is connected to the second guide member (41) and can drive the second guide member (41) to be close to or far away from the pole piece (S).

10. Pole piece forming device according to claim 1, characterized in that the second press roll assembly (22) comprises a second press roll (221) and a second driver (222), the second driver (222) being connected to the second press roll (221).