Pole piece surface modeling method

Abstract

The invention relates to a pole piece surface modeling method. The pole piece surface modeling method comprises the following steps: arranging a grid plate in a nozzle of a coating die cavity; pores are formed in the surface of the grid plate; obtaining slurry for the pole piece; coating the slurry on the surface of the pole piece; and rolling and forming to obtain the pole piece with the shape. As a further optimization scheme of the invention, the pole piece comprises a positive pole piece and a negative pole piece. As a further optimization scheme of the invention, the pole piece slurry comprises a positive pole piece slurry, and the positive pole piece slurry comprises NCA, CNT, KS-6 and PVDF. As a further optimization scheme of the invention, the positive plate slurry is coated on the surface of an aluminum layer of a composite microporous copper-aluminum current collector by a coating method to prepare an NCA single-sided positive electrode layer; according to the pole piece surface modeling method, the production cost is effectively reduced, the progress of a battery manufacturing process is promoted, and meanwhile, the requirement of the modern manufacturing industry for sustainable development is met.

Description

Technical Field

[0001] The invention belongs to the technical field of secondary ion battery processing, and in particular relates to a method for shaping the surface of a pole piece. Background Art

[0002] With the rapid development of renewable energy storage technology, the improvement of battery performance has become the focus of research. At the same time, higher requirements are placed on the energy density, fast charging capability and charge and discharge rate of lithium-ion batteries. High-energy-density fast-charging lithium batteries are the development trend of consumer lithium-ion batteries. However, with the increase in energy density, the thickness of the positive and negative electrodes in lithium-ion batteries becomes thicker and thicker, resulting in a longer transmission distance for lithium ions. In addition, when the charging speed becomes faster, lithium ions are more likely to gather on the surface of the negative electrode during the charging and discharging process, causing congestion on the surface of the negative electrode, which seriously affects the service life of lithium-ion batteries.

[0003] In the prior art, the above problems are solved by changing the shape of the electrode surface, that is, setting the corresponding concave and convex shapes to improve the overall performance and reliability of the battery; through further research, it is found that the surface shape of the battery electrode, the specific surface shape (such as grooves, corrugations, etc.) can promote the flow of electrolyte, improve the conduction efficiency of ions on the electrode, reduce internal resistance, and thus improve the power density of the battery; and reasonable electrode shape can reduce the uneven deposition of lithium ions during the charging and discharging process, reduce the mechanical stress of the electrode, and thus extend the cycle life of the battery; the surface shape with good thermal conductivity can effectively disperse the heat generated by the battery during the charging and discharging process, prevent the formation of hot spots, and ensure the safety and stability of the battery; the optimization of the surface shape can reduce the energy loss of the battery during the charging and discharging process and improve the overall energy conversion efficiency. By selecting appropriate surface treatment and shape design, the corrosion resistance of the electrode to the electrolyte can be enhanced, and the durability of the battery can be improved. The use of advanced shape technology (such as pore structure or lightweight design) can reduce the weight of the electrode while ensuring performance, which helps to make the overall battery lightweight and portable.

[0004] Patent CN 117239055 A provides a lithium ion battery. The lithium ion battery of the invention can improve the cycle life. The lithium-ion battery described in the invention includes a positive electrode sheet and a negative electrode sheet; the positive electrode sheet includes a positive electrode collector and a positive electrode coating on at least one side of the positive electrode collector, and the surface of the positive electrode coating away from the positive electrode collector contains a recess; the negative electrode sheet includes a negative electrode collector and a negative electrode coating on at least one side of the negative electrode collector, and the surface of the negative electrode coating away from the negative electrode collector contains a recess. The patent provides recesses on the surface of the positive electrode coating to improve the wettability of the electrolyte to the positive electrode active material close to the positive electrode collector, thereby improving the utilization rate of the positive electrode active material close to the positive electrode collector, improving the capacity, and improving the energy density and fast charging performance of the lithium-ion battery; and the recesses are provided on the surface of the negative electrode coating to fully improve the problem that lithium ions accumulate on the surface of the negative electrode sheet due to the large thickness of the negative electrode sheet and the long lithium ion transmission distance, and cannot be quickly embedded in the negative electrode active material close to the negative electrode collector, so that the negative electrode active material cannot be fully utilized, and lithium precipitation occurs on the surface of the negative electrode sheet, effectively improving the cycle life of the lithium-ion battery.

[0005] In the prior art pole piece shaping method, corresponding upper and lower shaping devices are generally provided, such as Figure 2 As shown, there is a boss on the surface of the lower molding device, and the positive or negative electrode sheet passes through the upper and lower molding devices. The upper molding device applies downward pressure to create pits or protrusions on the surface of the electrode sheet. However, in this molding method, when the bosses of the upper and lower molding devices are rolled on the surface of the electrode sheet, the electrode sheet will fall off, and after the electrode sheet is coated, a rolling process needs to be added. The electrode sheet will be scrapped in each process, which increases the production cost. Summary of the invention

[0006] The purpose of the present invention is to provide a method for shaping the surface of a pole piece with a simple structure and reasonable design in order to solve the above problems.

[0007] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0008] A method for shaping a pole piece surface, the method comprising the following steps:

[0009] A grid plate is arranged in the nozzle of the coating cavity;

[0010] The surface of the mesh plate is provided with pores;

[0011] Obtaining slurry for pole pieces;

[0012] Coating slurry on the surface of the pole piece;

[0013] The pole piece with shape is obtained by rolling and forming.

[0014] As a further optimization solution of the present invention, the electrode sheet includes a positive electrode sheet and a negative electrode sheet.

[0015] As a further optimization solution of the present invention, the electrode sheet slurry includes positive electrode sheet slurry, and the positive electrode sheet slurry includes NCA, CNT, KS-6, and PVDF.

[0016] As a further optimization scheme of the present invention, NCA:CNT:KS-6:PVDF in the positive electrode sheet slurry is equal to 97.8:0.5:0.5:1.2.

[0017] As a further optimization scheme of the present invention, the positive electrode sheet slurry is coated on the surface of the aluminum layer of the composite microporous copper-aluminum current collector by a coating method to prepare an NCA single-sided positive electrode layer.

[0018] As a further optimization scheme of the present invention, the electrode sheet slurry includes negative electrode sheet slurry, and the negative electrode sheet slurry includes silicon carbon, carbon black, CMC, and SBR.

[0019] As a further optimization scheme of the present invention, the ratio of silicon carbon: carbon black: CMC: SBR in the negative electrode sheet slurry is 95.1:1:1.6:2.3.

[0020] As a further optimization scheme of the present invention, the negative electrode sheet slurry is coated on the copper layer of the composite microporous copper-aluminum current collector by a coating method to prepare the negative electrode layer.

[0021] As a further optimization solution of the present invention, the pore shape of the surface of the grid plate is square.

[0022] As a further optimization solution of the present invention, the grid plate includes a connecting portion and a baffle, the connecting portion is crisscrossed, and the baffle is arranged at a corresponding node position.

[0023] As a further optimization scheme of the present invention, the surface density of the positive electrode sheet is 10 mg / cm 2 -35mg / cm 2 ;

[0024] And / or, the thickness of the positive electrode coating is 30 μm-110 μm;

[0025] And / or, the surface density of the negative electrode sheet is 7 mg / cm 2 -22mg / cm 2 ;

[0026] And / or, the thickness of the negative electrode coating is 35 μm-120 μm.

[0027] The beneficial effects of the present invention are as follows: the present invention has many advantages. First, the traditional boss design often causes material dropout when rolling on the surface of the pole piece, which affects product quality and may cause the production line to stop, resulting in production capacity loss. In addition, after the pole piece is coated, the additional rolling process will introduce additional material waste, and scrap may occur in each process, which significantly increases the production cost. In order to solve these problems, the present solution innovatively installs a grid plate at the nozzle of the coating cavity to shape bulges or pits on the surface of the pole piece; no rolling process is required, which prevents the pole piece from dropping due to rolling, and ensures the integrity and consistency of the pole piece. At the same time, by eliminating redundant rolling processes, the solution simplifies the production process chain, shortens the production cycle, improves the flexibility of the production line, and can better adapt to the production needs of different batches. The optimized surface modeling design also reduces friction and energy loss during the rolling process, further improving production efficiency. In addition, by reducing the scrap rate of materials and the complexity of the process, the solution effectively reduces the overall production cost, enabling enterprises to have a stronger cost advantage in the fiercely competitive market. Ultimately, due to the reduction of process steps and the elimination of material dropout, the consistency and repeatability of the final product have been significantly improved, which is crucial to the stability of battery performance. In summary, this solution comprehensively solves many pain points in traditional processes through innovative grid plates, which not only improves production efficiency and product quality, but also effectively reduces production costs, promotes the advancement of battery manufacturing technology, and meets the requirements of modern manufacturing for sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of a method flow of a pole piece surface shaping method of the present invention;

[0029] Figure 2 It is a schematic structural diagram of the coating cavity of the present invention;

[0030] Figure 3 The present invention Figure 2 Schematic diagram of the cross-sectional structure of AA in FIG.

[0031] Figure 4 It is a schematic diagram of the working principle of the coating cavity of the present invention;

[0032] Figure 5 It is a schematic diagram of the pole piece coating structure of the present invention;

[0033] Figure 6 It is a schematic diagram of the bottom structure of the nozzle of the present invention;

[0034] Figure 7 The present invention Figure 6 The enlarged structural diagram at D in FIG.

[0035] Figure 8 The present invention Figure 7 Schematic diagram of the cross-sectional structure of EE in FIG.

[0036] Fig. 9 It is a schematic diagram of the boss structure on the pole piece surface of the present invention;

[0037] Fig.10 The present invention Fig. 9 Schematic diagram of the cross-sectional structure of AA in the pole piece;

[0038] Fig.11 The present invention Fig.10 The enlarged structural diagram at B in FIG.

[0039] Fig.12 It is a schematic diagram of the convex point morphology during the performance test of the present invention;

[0040] Fig.13 It is another form of mesh plate of the present invention;

[0041] Fig.14 It is a schematic diagram of the pit structure of the present invention. DETAILED DESCRIPTION

[0042] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0043] refer to Figure 1 A method flow chart of a method for shaping the surface of a pole piece is shown in FIG. 1 . In this embodiment, a method for shaping the surface of a pole piece is disclosed. The method includes:

[0044] Step S102, setting a grid plate in the nozzle of the coating cavity;

[0045] Step S104, the surface of the mesh plate is provided with pores;

[0046] Step S106, obtaining a slurry for a pole piece;

[0047] Step S108, coating the slurry on the surface of the electrode;

[0048] Step S110, rolling and forming to obtain a pole piece with a shape.

[0049] It should be noted that there is no order of precedence between step S104 and step S106. The solution of the present application is mainly to form protrusions or grooves (pits) on the surface of the electrode by setting a grid plate at the nozzle of the coating cavity.

[0050] Setting regular protrusions or grooves on the surface of the battery electrode can significantly improve the overall performance and reliability of the battery.

[0051] This design increases the effective area of ​​the electrochemical reaction, thereby increasing the diffusion rate of lithium ions, thereby enhancing the battery's charge and discharge efficiency and power density.

[0052] The optimized surface structure promotes the flow of electrolyte, increases the ion conduction speed, reduces the internal resistance of the battery, and improves the charging and discharging performance. In addition, the regular surface design can also enhance the mechanical strength of the battery pole piece, improve its durability, and prevent structural damage during the charging and discharging process, thereby extending the battery life.

[0053] In terms of thermal management, the increased surface area helps improve heat dissipation efficiency and reduce temperature rise during high-power operation. At the same time, this optimized design may also reduce manufacturing costs, increase the cycle life of the battery, and improve the alignment accuracy of the pole pieces during the assembly process, ultimately improving the safety of the battery and reducing the risks of thermal runaway and short circuit.

[0054] refer to Figure 2 and Figure 3 The structure shown is actually a coating cavity structure. In the prior art, the coating cavity has a long and narrow gap, called a nozzle, and the width of the nozzle is about 2 mm.

[0055] refer to Figure 4 In the structure shown, when the coating cavity is in use, the cavity is filled with slurry, pressure is applied to the feed port, the slurry is evenly sprayed out from the nozzle, the negative electrode slurry is evenly coated on the copper foil, and the positive electrode slurry is evenly coated on the aluminum foil.

[0056] In this embodiment, the electrode sheet in the scheme includes a positive electrode sheet and a negative electrode sheet, that is, the protrusion and the groove can actually be applied to the positive electrode sheet and the negative electrode sheet, and the actual scheme of the present application can be applied to the positive electrode sheet and the negative electrode sheet. For details, please refer to Figure 5 Schematic diagram of the structure shown.

[0057] In actual use of this embodiment, you can refer to Figure 6 As shown in the structural schematic diagram, a grid plate is provided to cover the nozzle of the coating cavity. The coverage can be full coverage or partial coverage, and can actually be selected based on the preparation needs of the user.

[0058] The form of the grid plate can be referred to Figure 7 The structural schematic diagram shown in FIG. 1 shows that the embodiment is demonstrated by preparing the protrusions, so the position of the protrusions is the position of the pores on the surface of the grid plate. Figure 7 and Figure 8In the structure shown, the pores on the surface of the grid plate are in the shape of a square, the thickness of the grid plate is C, the grid has square through holes with a side length of B, the slurry can be sprayed out from the square through holes, the distance between the square and the square is A, and these distances are solid to prevent the slurry from flowing out of these parts. By adjusting the values ​​of A, B, and C, bulges and pits can be formed on the surface of the pole piece.

[0059] For specific convex forms, please refer to Fig. 9 , Fig.10 , Fig.11 and Fig.12 Style shown.

[0060] Furthermore, the electrode sheet slurry includes positive electrode sheet slurry, and the positive electrode sheet slurry includes NCA, CNT, KS-6, and PVDF.

[0061] Among them, in the positive electrode sheet slurry, NCA:CNT:KS-6:PVDF=97.8:0.5:0.5:1.2.

[0062] Furthermore, the positive electrode sheet slurry is coated on the surface of the aluminum layer of the composite microporous copper-aluminum current collector by a coating method to prepare an NCA single-sided positive electrode layer.

[0063] Furthermore, the electrode sheet slurry includes negative electrode sheet slurry, and the negative electrode sheet slurry includes silicon carbon, carbon black, CMC, and SBR.

[0064] Among them, the ratio of silicon carbon: carbon black: CMC: SBR in the negative electrode sheet slurry is 95.1:1:1.6:2.3.

[0065] Furthermore, the negative electrode sheet slurry is coated on the copper layer of the composite microporous copper-aluminum current collector by a coating method to prepare a negative electrode layer.

[0066] The following table is an embodiment scheme table:

[0067]

[0068] in:

[0069] Embodiment 1:

[0070] Grid plate parameters: A: 100μm; B: 150μm; C: 1mm.

[0071] Embodiment 2:

[0072] Grid plate parameters: A: 150μm; B: 150μm; C: 1mm.

[0073] Embodiment 3:

[0074] Grid plate parameters: A: 200μm; B: 150μm; C: 1mm.

[0075] Embodiment 4:

[0076] Grid plate parameters: A: 150μm; B: 100μm; C: 1mm.

[0077] Embodiment 5:

[0078] Grid plate parameters: A: 150μm; B: 150μm; C: 1mm.

[0079] Embodiment 6:

[0080] Grid plate parameters: A: 150μm; B: 200μm; C: 1mm.

[0081] Embodiment 7:

[0082] Grid plate parameters: A: 150μm; B: 150μm; C: 0.5mm.

[0083] Embodiment 8:

[0084] Grid plate parameters: A: 150μm; B: 150μm; C: 1mm.

[0085] Embodiment 9:

[0086] Grid plate parameters: A: 150μm; B: 150μm; C: 1.5mm.

[0087] The above embodiment was tested for performance. The specific direction of the performance test was as follows: 10 discs with a diameter of 30 mm were punched out in sequence along the width direction of the aluminum foil with a sampler, and the micro-shaped bumps ( Fig.12 Dimensions (as shown) are in um.

[0088] The following table is the experimental results of the positive electrode:

[0089]

[0090]

[0091] The following table is the negative electrode test results table:

[0092]

[0093]

[0094] From the above two tables we can see that:

[0095] In Examples 1 to 3, the side length of the square through hole and the grid thickness are fixed.

[0096] Experimental observation: As the grid spacing increases, the outer diameter and height of the boss on the pole piece surface both tend to increase.

[0097] Analysis and advantages:

[0098] Increased outer diameter and height: Increasing the grid spacing allows more slurry to accumulate after each through-hole is sprayed, forming larger protrusions. This means that taller structures can be designed, which helps improve the surface activity of the electrode.

[0099] Improve electrode performance: Higher protrusions can increase the electrochemical reaction area, thereby increasing the power density and energy density of the battery. In addition, the protrusions help improve the conduction of ions and improve the overall battery performance;

[0100] In Examples 4 to 6, the grid spacing and grid thickness are fixed.

[0101] Experimental observation: As the side length of the square through hole increases, the outer diameter and height of the boss on the pole piece surface tend to decrease.

[0102] Analysis and advantages:

[0103] Effect of via side length: Increasing the via side length may result in a decrease in the accumulation of slurry in each via after injection, resulting in a smaller protrusion. This indicates that during design, the size of the via needs to be reasonably matched with the amount of slurry injected to achieve the best protrusion shape and performance.

[0104] Optimizing design: This observation prompts designers to be careful in selecting the via side length to ensure that the appropriate protrusion effect can still be obtained under different conditions, thereby better controlling the surface properties of the electrode.

[0105] In Examples 7 to 9, the grid spacing and the side length of the square through holes are fixed.

[0106] Experimental observation: As the grid thickness increases, the outer diameter and height of the boss on the pole piece surface both tend to increase.

[0107] Analysis and advantages:

[0108] Effect of thickness: Thicker grid plates can support higher pressure, allowing for better deposition of the slurry after spraying. This helps form more stable protrusions, improving the mechanical strength and durability of the electrode.

[0109] Improve production efficiency: In actual production, using thicker mesh can improve the stability of the spraying process, ensure uniform spraying of slurry, and reduce uncertainty in the production process;

[0110] The difference between positive and negative electrodes.

[0111] Experimental observation: The shape of the positive electrode sheet is obviously better than that of the negative electrode sheet, which is related to the difference in slurry viscosity.

[0112] Analysis and advantages:

[0113] Effect of slurry viscosity: The viscosity of positive electrode slurry is higher than that of negative electrode slurry, which means that during the spraying process, the positive electrode slurry is more likely to remain in its desired position after being sprayed, forming a more obvious bulge. This provides more space for surface optimization of the positive electrode and improves the electrochemical performance of the positive electrode.

[0114] Design strategy: For slurries of different viscosities, the injection parameters and grid design can be adjusted to optimize the structure of the two pole pieces and ensure balanced battery performance.

[0115] Furthermore, in addition to this embodiment, a grid plate is also provided, such as Fig.13 As shown, the grid plate includes a connecting portion and a baffle, the connecting portion is crisscrossed, and the baffle is arranged at the corresponding node position.

[0116] The size of the pit can be controlled by adjusting the size of the baffle.

[0117] Specifically, the baffle can be round or square, preferably square.

[0118] It should also be noted that the grid plate is more convenient to use when preparing pits. Relatively speaking, the connecting part is narrow and generally cannot well block the slurry sprayed from the nozzle. Even if there is a corresponding shallow horizontal, it can be eliminated by rolling. Moreover, it is conducive to the rolling forming of the pole piece. Traditional rolling will also produce slag. For details, please refer to Fig.14 Schematic diagram of the pit shape shown.

[0119] It should be noted that the method of pole piece surface shaping is intended to effectively solve several key problems faced by battery pole pieces during the production process. First, the traditional boss design often causes material shedding when rolling on the pole piece surface, which affects product quality and may cause the production line to stop, resulting in production capacity loss. In addition, after the pole piece is coated, the additional rolling process will introduce additional material waste, and scrap may occur in each process, significantly increasing the production cost. In order to solve these problems, this solution innovatively installs a grid plate at the nozzle of the coating cavity to shape bulges or pits on the pole piece surface; no rolling process is required, which prevents the pole piece from shedding due to rolling and ensures the integrity and consistency of the pole piece. At the same time, by eliminating redundant rolling processes, the solution simplifies the production process chain, shortens the production cycle, improves the flexibility of the production line, and can better adapt to the production needs of different batches. The optimized surface shaping design also reduces friction and energy loss during rolling, further improving production efficiency. In addition, by reducing the scrap rate of materials and the complexity of the process, the solution effectively reduces the overall production cost, giving enterprises a stronger cost advantage in the highly competitive market. Ultimately, due to the reduction of process steps and the elimination of material dropout, the consistency and repeatability of the final product have been significantly improved, which is crucial to the stability of battery performance. In summary, this solution comprehensively solves many pain points in traditional processes through innovative grid plates, which not only improves production efficiency and product quality, but also effectively reduces production costs, promotes the advancement of battery manufacturing technology, and meets the requirements of modern manufacturing for sustainable development, which helps to enhance the corporate social responsibility image.

[0120] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0121] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0122] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

[0123] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for shaping the surface of a pole piece, characterized in that: The method comprises the following steps, A grid plate is arranged in the nozzle of the coating cavity; The surface of the mesh plate is provided with pores; Obtaining slurry for pole pieces; Coating slurry on the surface of the pole piece; Wherein, the electrode sheet includes a positive electrode sheet and a negative electrode sheet; The pole piece with shape is obtained by rolling and molding.

2. A method for shaping a pole piece surface according to claim 1, characterized in that: The electrode sheet slurry includes positive electrode sheet slurry, and the positive electrode sheet slurry includes NCA, CNT, KS-6, and PVDF.

3. A method for shaping a pole piece surface according to claim 2, characterized in that: In the positive electrode sheet slurry, NCA:CNT:KS-6:PVDF=97.8:0.5:0.5:1.

2.

4. A method for shaping a pole piece surface according to claim 3, characterized in that: The positive electrode sheet slurry is coated on the surface of the aluminum layer of the composite microporous copper-aluminum current collector by a coating method to prepare an NCA single-sided positive electrode layer.

5. A method for shaping a pole piece surface according to claim 1, characterized in that: The electrode sheet slurry includes negative electrode sheet slurry, and the negative electrode sheet slurry includes silicon carbon, carbon black, CMC, and SBR.

6. A method for shaping a pole piece surface according to claim 5, characterized in that: In the negative electrode sheet slurry, silicon carbon: carbon black: CMC: SBR = 95.1: 1: 1.6: 2.

3.

7. A method for shaping a pole piece surface according to claim 6, characterized in that: The negative electrode sheet slurry is coated on the copper layer of the composite microporous copper-aluminum current collector by a coating method to prepare a negative electrode layer.

8. A method for shaping a pole piece surface according to claim 1, characterized in that: The pores on the surface of the grid plate are in a square shape.

9. A method for shaping a pole piece surface according to claim 1, characterized in that: The grid plate includes a connecting portion and a baffle, the connecting portion is crisscrossed, and the baffle is arranged at a corresponding node position.

10. A method for shaping a pole piece surface according to claim 1, characterized in that: The surface density of the positive electrode sheet is 10 mg / cm 2 -35mg / cm 2 ; And / or, the thickness of the positive electrode coating is 30 μm-110 μm; And / or, the surface density of the negative electrode sheet is 7 mg / cm 2 -22mg / cm 2 ; And / or, the thickness of the negative electrode coating is 35 μm-120 μm.

Images