Lithium battery electrode processing device and method

Abstract

The present invention provides a lithium battery electrode sheet processing device and method. The device includes: a rolling roll, a guiding roll, a first main driving roll, a second main driving roll, a heating unit, a pressing unit and a rubber roll; the rolling roll, the guiding roll, the second main driving roll and the first main driving roll are arranged in sequence along the traveling direction of the electrode sheet. The rolling roll includes a first rolling roll and a second rolling roll arranged up and down. The heating unit is connected to the second main driving roll and is used to heat the second main driving roll. The pressing unit is located above the second main driving roll and is used to press the tab blank area of the electrode sheet on the roll surface of the second main driving roll. The rubber roll is correspondingly arranged below the first main driving roll, and the speeds and / or tensions of the first main driving roll and the second main driving roll are different. By heating the tab blank area after the electrode sheet is roll-pressed to change the hardness of the base material itself, and at the same time stretching the tab blank area under the cooperation of the tensile force generated by the ratio difference between the first main driving roll and the second main driving roll and the pressure generated by the pressing unit, the present invention can effectively solve the problem of tape breakage.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery preparation, and particularly to a lithium battery electrode sheet processing device and method. Background Art

[0002] With the rapid development of the lithium battery industry and the continuous improvement of residents' consumption demands, lithium batteries are increasingly widely used, and higher requirements are also put forward for their energy storage performance and safety. The manufacturing process of lithium batteries is complex and involves many processes. Any mistake in any link will affect the performance of lithium batteries and pose potential safety hazards. Therefore, only by strictly controlling each manufacturing process can excellent-performance and safe lithium battery products be manufactured. Among the entire manufacturing process of lithium batteries, rolling is a very crucial process. During the production and manufacturing of lithium batteries, the battery electrode sheets are usually processed by rolling to achieve a relatively large compaction density, which is beneficial to improving the energy density of the battery. Currently, there are two types of rolling methods in the industry. One is cold rolling, that is, the electrode sheets are rolled without any treatment of the physical properties of the rolling rolls. The second is hot rolling, usually with the surface of the rolling rolls heated to better achieve the compaction density of the electrode sheets. When the coated electrode sheets are rolled under a certain pressure, although the compaction density will change significantly, at the same time, due to the two-way force on the electrode sheets, the coated area will be laterally extended, while the uncoated empty foil in the uncoated area will not be extended because it is not stressed. Therefore, in the prior art, a stretching device is generally used to forcibly extend the tab blank area (i.e., the area without coated slurry) of the electrode sheets to relieve the wrinkling of the electrode sheets.

[0003] Figure 1 The structure diagram of a device commonly used at present for stretching the tab blank area of the electrode sheets is shown. This device is usually called a Pinch stretching mechanism, which mainly consists of a main drive steel roll 11, a rubber roll 12, and a swing roll 13. After the electrode sheets are rolled, the extension of the tab blank area is completed by the Pinch stretching mechanism. Because multiple layers of Teflon layers are pasted on the designated area of the swing roll 13, under the stretching condition of a large tension (such as a tension of 200N - 400N), a height difference of more than 1.3 times is formed between the position of the tab blank area and the slurry-coated area of the electrode sheets under the action of the swing roll 13 and the Teflon layers. At this time, the tab blank area is subjected to two tensile forces, namely Figure 1 the F① and F② back forces shown in, although the problems of tab blank area extension and wrinkling are solved, because the tab blank area is subjected to two back forces at this position, the stress points at this position of the tab blank area are prominent, and problems such as surface defects, pits, pinholes, cracks, and uneven foil hardness are infinitely magnified, resulting in over-extension and a breakage rate of more than 70% at this position of the electrode sheets, leading to a decrease in production yield and an increase in production cost. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a lithium battery pole piece processing device and method, which are used to solve the problems in the prior art that when stretching the ear blanking area of the pole piece by a stretching device composed of a main driving steel roller, a rubber roller and a swinging roller, the blanking area is subjected to two opposite forces at the position where it contacts the swinging roller, resulting in the stress point protruding at this position, and surface defects, pits, pinholes, cracks, uneven foil hardness and other problems being infinitely magnified, causing over-extension of the pole piece at this position and the breakage rate > 70%, resulting in a decrease in production yield and an increase in production cost.

[0005] To achieve the above object and other related objects, the present invention provides a lithium battery pole piece processing device, including: a rolling roller, a passing roller, a first main driving roller, a second main driving roller, a heating unit, a pressing unit and a rubber roller; the rolling roller, the passing roller, the second main driving roller and the first main driving roller are arranged in sequence along the traveling direction of the pole piece, the rolling roller includes a first rolling roller and a second rolling roller arranged corresponding to each other up and down, the heating unit is connected to the second main driving roller for heating the second main driving roller, the pressing unit is located above the second main driving roller for pressing the ear blanking area of the pole piece on the roller surface of the second main driving roller, the rubber roller is correspondingly arranged below the first main driving roller, and the speeds and / or tensions of the first main driving roller and the second main driving roller are different.

[0006] Optionally, the pressing unit includes a pressing roller and a cylinder for applying pressure to the pressing roller.

[0007] Optionally, the pressing roller includes any one of a steel roller and a rubber roller.

[0008] More optionally, the pressure applied by the cylinder is 0.5 MPa - 0.7 Mpa.

[0009] Optionally, the heating unit includes a hot oil pipeline arranged in the second main driving roller, and the lithium battery pole piece processing device further includes a hot oil injection device communicated with the hot oil pipeline.

[0010] Optionally, the temperature of the injected hot oil is 120 °C - 160 °C.

[0011] Optionally, the speed ratio of the first main driving roller and the second main driving roller is 1.010 - 1.045.

[0012] Optionally, the radius of the second main driving roller is greater than the radius of the first main driving roller.

[0013] The present invention also provides a lithium battery pole piece processing method, including:

[0014] Providing a pole piece and the lithium battery pole piece processing device as described in any of the above solutions, the pole piece includes a slurry coating area and an ear blanking area located beside the slurry coating area;

[0015] During the process of the electrode sheet being rolled by the roller, the electrode sheet is compressed and extended in the longitudinal direction, and the blank area of the tab is suspended and not stressed, so it is not extended in the transverse and longitudinal directions;

[0016] After being compressed and extended, the electrode sheet passes through a roller, and the wrap angle changes on the second main driving roller, causing the blank area of the tab of the electrode sheet to be stressed on the roller and the second main driving roller. When the electrode sheet passes through the second main driving roller, the heating unit is started to heat the blank area of the tab. At the same time, the pressing unit presses on the blank area of the tab with the same width, and under the cooperation of the pulling force generated by the ratio difference of the speeds and / or tensions of the first main driving roller and the second main driving roller, the blank area of the tab is extended.

[0017] Optionally, the electrode sheet includes two or more slurry coating areas arranged at intervals and blank areas of tabs located between the slurry coating areas and outside the slurry coating areas.

[0018] As described above, the lithium battery electrode sheet processing device and method of the present invention have the following beneficial effects: The improved structural settings of the present invention can optimize the extension treatment of the blank area of the tab of the continuously coated battery electrode sheet. When compacting the battery electrode sheet, by heating the blank area of the tab after rolling the electrode sheet to change the hardness of the base material itself, and at the same time, under the cooperation of the pulling force generated by the ratio difference of the first main driving roller and the second main driving roller and the pressure generated by the pressing unit (these three factors are indispensable and cooperate with each other), the blank area of the tab is extended, which can avoid or eliminate the problem of belt breakage caused by stress concentration due to appearance defects of the electrode sheet, insufficient ductility of the foil material, etc. during the extension of the blank area of the tab, ensure the forming quality of the lithium battery electrode sheet, significantly improve the processing yield of the electrode sheet, and reduce the production cost. Brief Description of the Drawings

[0019] Figure 1 It shows a schematic structural diagram of a device for stretching the blank area of the tab of an electrode sheet in the prior art.

[0020] Figure 2 It shows a schematic structural diagram of the lithium battery electrode sheet processing device provided by the present invention.

[0021] Description of Component Symbols

[0022] 21 First roller

[0023] 22 Second roller

[0024] 23 Roller

[0025] 24 First main driving roller

[0026] 25 Second main driving roller

[0027] 251 Hot oil injection port

[0028] 26 Pressing roller

[0029] 27 Cylinder

[0030] 28 Rubber Roller

[0031] 29 Electrode Tab Detailed Implementation Modes

[0032] The following specific examples illustrate the implementation modes of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. When detailing the embodiments of the present invention, for ease of description, the cross-sectional views showing the device structure will be enlarged locally in a non-general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention here. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

[0033] For the convenience of description, spatial relationship terms such as "under", "below", "lower than", "beneath", "above", "on", etc. may be used herein to describe the relationship between one element or feature shown in the drawings and other elements or features. It will be understood that these spatial relationship terms are intended to encompass other directions of the device in use or operation in addition to the directions depicted in the drawings. Further, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or there can be one or more intervening layers.

[0034] In the context of the present application, the structure in which the first feature is "above" the second feature may include embodiments where the first and second features are formed in direct contact, and may also include embodiments where additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0035] It should be noted that the drawings provided in this embodiment only illustrate the basic concept of the present invention schematically. Therefore, only the components related to the present invention are shown in the drawings, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex. To make the drawings as concise as possible, not all structures are labeled in each drawing.

[0036] Please refer to Figure 2 。

[0037] As Figure 2As shown in the figure, the present invention provides a lithium battery pole piece processing device, including: a rolling mill, a passing roller 23, a first main driving roller 24, a second main driving roller 25, a heating unit, a pressing unit, and a rubber roller 28; the rolling mill, the passing roller, the second main driving roller 25, and the first main driving roller 24 are arranged in sequence along the traveling direction of the pole piece 29. The rolling mill is usually arranged in pairs. For example, in this embodiment, the rolling mill includes a first rolling mill 21 and a second rolling mill 22 which are arranged corresponding to each other up and down. The specifications and dimensions of the two are preferably exactly the same and are located on the same vertical line, but the rotation directions of the two are preferably opposite. For example Figure 2As shown, the first roller 21 rotates in the clockwise direction while the second roller 22 rotates in the counterclockwise direction, or the first roller 21 rotates in the counterclockwise direction while the second roller 22 rotates in the clockwise direction, thereby providing stable and uniform rolling for the electrode sheet 29; the passing roller 23 presses on the electrode sheet 29, and the electrode sheet 29 that has been rolled by the rollers passes through the passing roller, and the wrap angle changes on the second main driving roller 25. The rotation direction of the passing roller 23 is preferably opposite to the rotation direction of the second main driving roller 25. For example, the second main driving roller 25 rotates in the counterclockwise direction while the passing roller 23 rotates in the clockwise direction. The rotation direction of the first main driving roller 24 is generally also set to be opposite to the rotation direction of the second main driving roller 25, for example, rotating in the clockwise direction. The first main driving roller 24 and the second main driving roller 25 are driven by different driving devices, so the rotational speeds of the two can be adjusted as needed to change the speed difference between them; in addition, the passing roller 23 can also move up and down under the drive of the driving mechanism, thereby changing the tension of the tab; of course, the lithium battery electrode sheet processing device can also be provided with a tension adjusting roller separately to adjust the tension of the electrode sheet as needed, and this is not limited; the heating unit is connected to the second main driving roller 25 and is used to heat the second main driving roller 25, thereby heating the tab blank area of the electrode sheet passing through the second main driving roller 25. The pressing unit is located directly above the second main driving roller 25 and is used to press the tab blank area of the electrode sheet 29 on the roller surface of the second main driving roller 25; to ensure that the tab blank area is as close as possible to the roller surface of the second main driving roller 25 during the pressing process, the pressing unit usually includes a pressing mechanism with an arc-shaped surface. For example, in the preferred example provided by the present invention, the pressing unit includes a pressing roller and a driving unit for driving the pressing roller to press. The radius of the pressing roller is usually much smaller than the radius of the second main driving roller 25 to make it have a relatively small volume and reduce the power consumption of the driving unit; in a specific example, the pressing roller is a steel roller or a rubber roller with a heat-resistant rubber layer wound on the surface of a metal roller, and the driving unit can be a cylinder 27 or other power mechanisms that can be lifted to press the pressing roller, but choosing the cylinder 27 is more convenient for adjusting the pressing pressure; the rubber roller 28 is correspondingly arranged below the first main driving roller 24 to cooperate with the first main driving roller 24 to provide a tensile force for the electrode sheet. The speeds and / or tensions of the first main driving roller 24 and the second main driving roller 25 are different, so different forces in two different directions are provided to the tab blank area to generate a tensile force on the tab blank area to extend the tab blank area; the electrode sheet usually includes a slurry coating area and a tab blank area located outside the slurry coating area, that is, the tab blank area is not coated with a slurry layer, so it has a different thickness from the slurry coating area, and there can be more than one slurry coating area, for example, two. The two slurry coating areas are arranged at intervals, and the tab blank area is arranged in the interval area and outside of the two slurry coating areas to ensure that there is a tab blank area on both sides of each slurry coating area after subsequent slitting.

[0038] The exemplary working process of the lithium battery electrode sheet processing device provided in this embodiment is as follows: The electrode sheet 29 to be processed is unrolled onto the lithium battery electrode sheet processing device of this embodiment. The electrode sheet 29 includes a slurry coating area and an ear blanking area beside the slurry coating area. The method of unrolling the electrode sheet is well-known to those skilled in the art and will not be elaborated in detail here;

[0039] During the process of the electrode sheet 29 being rolled by the roller, the electrode sheet 29 is compressed and extended in the longitudinal direction (the force directions in this process can be referred to Figure 1 F① and F② in). Since the thickness of the slurry coating area is greater than that of the ear blanking area, the slurry coating area comes into contact with the roller surface of the roller and is rolled, while the ear blanking area is suspended and not stressed and is not extended in the transverse and longitudinal directions;

[0040] After being compressed and extended, the electrode sheet 29 passes through the idler roller 23, and the wrap angle changes on the second main driving roller 25, so that the ear blanking area of the electrode sheet is stressed on the idler roller and the second main driving roller 25. When the electrode sheet 29 passes through the second main driving roller 25, the heating unit is started. The heating temperature of the heating unit is preferably 120°C to 160°C. The ear blanking area can come into contact with the roller surface of the second main driving roller 25 to heat the ear blanking area. At the same time, the pressing unit presses on the ear blanking area of the same width (that is, the axial width of the aforementioned pressing roller corresponds to the width of the ear blanking area). For example, the cylinder 27 is inflated, and the pressing roller presses down on the ear blanking area under a pressure of 0.5 MPa to 0.7 MPa, and under the cooperation of the pulling force generated by the ratio difference of the speeds and / or tensions of the first main driving roller 24 and the second main driving roller 25, the ear blanking area is extended. In the above process, when the electrode sheet 29 passes through the idler roller 23, a large wrap angle fit is formed under the action of the second main driving roller 25, increasing the heating area and heating time of the ear blanking area. After the ear blanking area is heated, the flexibility of the foil material becomes larger. Under the action of the pressure of the pressing roller and the cooperation of the pulling force generated by the ratio difference (speed / tension) of the first main driving roller 24 and the second main driving roller 25, the ear blanking area is subjected to Figure 2 the acting forces in the two directions of F3 and F4 shown in (these two forces are one along the longitudinal direction and one along the advancing direction of the electrode sheet, not a pair of opposite forces), realizing the extension of the ear blanking area, thereby effectively avoiding the risk of batch belt breakage caused by the pulling phenomenon of two opposite forces when using the existing Pinch stretching structure.

[0041] The improved structural arrangement of the present invention can optimize the extension treatment of the tab blank area of the lithium battery electrode sheet during continuous coating. When compacting the battery electrode sheet, after the electrode sheet is roll-pressed, the tab blank area is heated to change the hardness of the base material itself. At the same time, under the cooperation of the tensile force generated by the ratio difference between the first main driving roller and the second main driving roller and the pressure generated by the pressing unit (these three factors are indispensable and cooperate with each other. For example, if there is no pressing of the pressing unit, the tab blank area will be pulled by two opposite forces and cause the tape to break, and if heated, the extension effect will be greatly reduced), the tab blank area is extended, which can avoid or eliminate the tape-breaking problem caused by stress concentration due to problems such as appearance defects of the electrode sheet and insufficient ductility of the foil during the extension of the tab blank area, ensure the forming quality of the lithium battery electrode sheet, can significantly improve the processing yield of the electrode sheet, and reduce the production cost.

[0042] In this example, the pressure applied by the pressing unit to the tab blank area is preferably 0.5 MPa to 0.7 Mpa, and using the air cylinder 27 is beneficial for accurately controlling the pressing pressure.

[0043] The second main driving roller 25 can adopt a suitable heating method, such as heating with a resistance wire. However, in the preferred example provided by the present invention, the heating unit includes a hot oil pipeline disposed in the second main driving roller 25. The lithium battery electrode sheet processing device further includes a hot oil injection device connected to the hot oil pipeline, for example, connected to a hot oil injection port 251 disposed on the end face of the hot oil pipeline. Heating with hot oil is more conducive to uniform temperature control compared to other methods. To achieve more precise temperature control, a temperature control device can also be provided to measure and adjust the temperature on the surface of the second main driving roller 25 in real time to ensure that it is controlled at the required heating temperature. For example, in a preferred example, the temperature of the injected hot oil is 120 °C to 160 °C.

[0044] The first main driving roller 24 and the second main driving roller 25 can have different rotational speeds but provide the same tension to the electrode sheet 29, or provide different tensions but the same rotational speed, or both the rotational speed and the provided tension are different. Preferably, the rotational speeds of the two are different, and preferably the rotational speed of the first main driving roller 24 is greater than the rotational speed of the second main driving roller 25. For example, the speed ratio of the first main driving roller 24 to the second main driving roller 25 is 1.010 to 1.045, and the radius of the second main driving roller 25 is preferably greater than the radius of the first main driving roller 24. For example, the radius of the second main driving roller 25 is 1.5 to 2 times the radius of the first main driving roller 24, which is not only convenient for adjusting the tensile force of the tab blank area, but also can increase the heat absorption area and heat absorption time when the tab blank area contacts the second main driving roller 25, further improving the extension effect of the tab blank area.

[0045] The present invention also provides a method for processing a lithium battery electrode sheet, including: providing an electrode sheet 29 and the lithium battery electrode sheet processing device as described in any of the above solutions. Therefore, the introduction of the lithium battery electrode sheet processing device can be fully cited here. For the sake of brevity, it will not be repeated. The electrode sheet 29 includes a slurry coating area and an ear blank area located beside the slurry coating area. The slurry coating area can be single or more than two. When there are more than two, the more than two slurry coating areas are arranged at intervals, and the ear blank area is located between the slurry coating areas and outside the slurry coating areas, that is, ear blank areas are arranged on both sides of each slurry coating area.

[0046] During the process of the electrode sheet 29 being rolled by the roller, the electrode sheet 29 is compressed and extended in the longitudinal direction, and the ear blank area is suspended and not stressed, so it is not extended in the transverse and longitudinal directions.

[0047] After being compressed and extended, the electrode sheet 29 passes through the idler roller 23 (without passing through the Pinch stretching mechanism in the prior art), and the wrap angle changes on the second main driving roller 25, so that the ear blank area of the electrode sheet 29 is stressed on the idler roller and the second main driving roller 25. When the electrode sheet 29 passes through the second main driving roller 25, the heating unit is started to heat the ear blank area. For example, hot oil heating at 120°C to 160°C is used. At the same time, the pressing unit presses on the ear blank area with the same width, and under the cooperation of the pulling force generated by the ratio difference of the speeds and / or tensions of the first main driving roller 24 and the second main driving roller 25, the ear blank area is extended.

[0048] Compared with the prior art, when using the method of the present invention to process the electrode sheet, the problem of tape breakage caused by stress concentration during the extension of the ear blank area can be avoided or eliminated, ensuring the forming quality of the lithium battery electrode sheet.

[0049] Currently, this device and method have been widely applied in the factory where the inventor is located, and the problem of electrode sheet breakage has been effectively solved, bringing huge economic benefits to the enterprise.

[0050] In summary, the present invention provides a lithium battery electrode sheet processing device and method. The device includes: a rolling roller, a guiding roller, a first main driving roller, a second main driving roller, a heating unit, a pressing unit, and a rubber roller; the rolling roller, the guiding roller, the second main driving roller, and the first main driving roller are sequentially arranged along the traveling direction of the electrode sheet. The rolling roller includes a first rolling roller and a second rolling roller arranged corresponding to each other up and down. The heating unit is connected to the second main driving roller and is used to heat the second main driving roller. The pressing unit is located above the second main driving roller and is used to press the tab blank area of the electrode sheet on the roller surface of the second main driving roller. The rubber roller is correspondingly arranged below the first main driving roller, and the speeds and / or tensions of the first main driving roller and the second main driving roller are different. With the improved structural arrangement of the present invention, an optimized stretching treatment can be performed on the tab blank area of the continuously coated battery electrode sheet. When compacting the battery electrode sheet, the hardness of the base material itself is changed by heating the tab blank area after the electrode sheet is roll-pressed. At the same time, under the cooperation of the tensile force generated by the ratio difference between the first main driving roller and the second main driving roller and the pressure generated by the pressing unit (these three factors are indispensable and cooperate with each other), the tab blank area can be stretched, which can avoid or eliminate the problem of tape breakage caused by stress concentration due to problems such as appearance defects of the electrode sheet and insufficient ductility of the foil material during the stretching of the tab blank area, ensuring the forming quality of the lithium battery electrode sheet, significantly improving the processing yield of the electrode sheet, and reducing the production cost. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0051] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A lithium battery electrode sheet processing device, characterized in that, it includes: a rolling roll, a guiding roll, a first main driving roll, a second main driving roll, a heating unit, a pressing-down unit and a rubber roll; the rolling roll, the guiding roll, the second main driving roll and the first main driving roll are arranged in sequence along the traveling direction of the electrode sheet. The rolling roll includes a first rolling roll and a second rolling roll which are arranged corresponding to each other up and down. The heating unit is connected to the second main driving roll and is used for heating the second main driving roll. The pressing-down unit is located above the second main driving roll and is used for pressing down the tab blank area of the electrode sheet on the roll surface of the second main driving roll. The pressing-down unit includes a pressing-down roll and a cylinder for applying pressure to the pressing-down roll. The rubber roll is correspondingly arranged below the first main driving roll. The speeds and tensions of the first main driving roll and the second main driving roll are different, and the speed ratio of the first main driving roll to the second main driving roll is 1.010 - 1.

045.

2. The lithium battery electrode sheet processing device according to claim 1, characterized in that, the pressing-down roll includes any one of a steel roll and a rubber roll.

3. The lithium battery electrode sheet processing device according to claim 1, characterized in that, the pressure applied by the cylinder is 0.5 MPa - 0.7 Mpa.

4. The lithium battery electrode sheet processing device according to claim 1, characterized in that, the heating unit includes a hot oil pipeline arranged in the second main driving roll, and the lithium battery electrode sheet processing device further includes a hot oil injection device connected to the hot oil pipeline.

5. The lithium battery electrode sheet processing device according to claim 4, characterized in that, the temperature of the injected hot oil is 120 °C - 160 °C.

6. The lithium battery electrode sheet processing device according to claim 1, characterized in that, the radius of the second main driving roll is larger than the radius of the first main driving roll.

7. A lithium battery electrode sheet processing method, characterized in that, it includes: providing an electrode sheet and the lithium battery electrode sheet processing device according to any one of claims 1 - 6. The electrode sheet includes a slurry coating area and a tab blank area located beside the slurry coating area. The width of the pressing-down roll along the axial direction corresponds to the width of the tab blank area; during the process of the electrode sheet being rolled by the rolling roll, the electrode sheet is compressed and extended in the longitudinal direction, and the tab blank area is suspended and not stressed and is not extended in the transverse and longitudinal directions; after being compressed and extended, the electrode sheet passes through the guiding roll, and the wrap angle changes on the second main driving roll, so that the tab blank area of the electrode sheet is stressed on the guiding roll and the second main driving roll. When the electrode sheet passes through the second main driving roll, the heating unit is started to heat the tab blank area, and at the same time, the pressing-down unit presses on the tab blank area, and under the cooperation of the pulling force generated by the ratio difference of the speeds and tensions of the first main driving roll and the second main driving roll, the tab blank area is extended.

8. The lithium battery electrode sheet processing method according to claim 7, characterized in that, the electrode sheet includes two or more slurry coating areas arranged at intervals and tab blank areas located between the slurry coating areas and outside the slurry coating areas.

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