Battery cell structure and manufacturing method and application thereof

Abstract

The invention belongs to the technical field of batteries, and provides a battery cell structure and a manufacturing method and application thereof, the manufacturing method comprises the following steps: forming a plurality of positive electrode insulation partitions arranged at intervals on a to-be-coated surface of a positive electrode current collector, and forming a positive electrode active layer in an area between every two adjacent positive electrode insulation partitions to obtain a positive electrode roll; and unwinding the positive electrode insulation partition, a negative electrode roll and a solid electrolyte membrane roll, carrying out rolling compounding to obtain a composite electrode roll, and cutting the positive electrode insulation partition to obtain the battery cell structure. The positive electrode insulation partition can insulate the periphery of the positive electrode active layer with a smaller area, can compensate the size difference of the positive electrode and the negative electrode, and provides support for the negative electrode in the subsequent rolling compounding process, so that the sizes of the positive electrode and the negative electrode are consistent, and the problem of short circuit caused by edge shearing stress during pressure application is solved; roll-in compounding can effectively improve densification and improve electrolyte interface contact, and the manufacturing method is simple, convenient, economical, efficient and suitable for mass production.

Description

Technical Field

[0001] The present invention belongs to the technical field of batteries and relates to a battery core structure and a manufacturing method and application thereof. Background Art

[0002] As a new generation of high energy density energy storage devices, all-solid-state batteries have received widespread attention in recent years. Its core structure is usually composed of a positive electrode layer, a solid electrolyte layer and a negative electrode layer stacked in sequence. The functional layers form a complete electrochemical system through physical contact and interface bonding. In this type of battery, since the solid electrolyte does not have the fluidity and self-wetting properties of the liquid electrolyte, the interface contact quality between the functional layers has a decisive influence on the overall performance of the battery. In order to ensure good ion transmission channels and low interface impedance, a pressurization treatment process is usually required in the preparation process to increase the tightness between the materials and improve the interface bonding state.

[0003] In the current mainstream all-solid-state battery manufacturing process, electrode sheet size is typically designed so that the negative electrode sheet is larger than the positive electrode sheet. This strategy is primarily intended to avoid the risk of internal short circuits caused by exposed positive electrode edges during subsequent assembly. However, while this structural design improves battery safety to a certain extent, it also introduces new challenges during the subsequent pressurization and molding process.

[0004] Specifically, after the electrode stack assembly and packaging are completed, isostatic pressing technology is usually required to apply uniform pressure to the entire battery cell assembly to improve the density of the electrode and electrolyte layers and promote the formation of more stable mechanical and electrochemical contact between the layers. Isostatic pressing treatment places the battery to be treated in a closed container filled with liquid, and uses an external hydraulic system to apply uniform pressure so that the sample is subjected to the same stress in all directions, thereby achieving material densification and interface optimization. However, when there is a difference in the size of the positive and negative electrode sheets, a significant thickness difference will be formed in the edge area of ​​the battery cell, resulting in inconsistent stress states in different areas, which in turn generates shear stress, causing the solid electrolyte membrane to rupture here, forming microcracks or even penetrating defects, thereby destroying the integrity of the electrode / electrolyte interface and increasing the risk of local short circuits.

[0005] Secondly, isostatic pressing equipment essentially belongs to high-pressure containers, and its operation conditions are strict and complicated. It not only needs to be equipped with a high-strength pressure-resistant shell and a sealing device, but also needs to have precise pressure control and safety guarantee mechanisms. This makes the investment cost of the equipment high, and also accompanied by high energy consumption and maintenance costs in the daily operation process. In addition, since the isostatic pressing process must be carried out in a closed environment, the entire process is relatively closed, and it is difficult to realize real-time monitoring and online control. For example, during the pressurization process, if local stress concentration or material deformation anomaly occurs inside the battery cell, the operator cannot discover and take intervention measures in time, which may cause product defects or even safety accidents.

[0006] Therefore, it is still necessary to explore a more efficient and controllable related manufacturing and forming technology to solve the process problems of the current all-solid-state battery under the condition that the sizes of the pole pieces are inconsistent, and to promote its large-scale industrial application. SUMMARY

[0007] In view of the problems in the prior art, the present application provides a battery cell structure and a manufacturing method and use thereof. The manufacturing method comprises forming a plurality of positive electrode insulation partitions spaced apart on the to-be-coated surface of the positive electrode current collector, forming a positive electrode active layer in the region between every two adjacent positive electrode insulation partitions, to obtain a positive electrode roll; then unwinding the positive electrode roll, a negative electrode roll and a solid-state electrolyte membrane roll, and performing roll pressing and compounding to obtain a composite electrode roll; and then cutting the positive electrode insulation partitions to obtain the battery cell structure. The positive electrode insulation partitions not only insulate the surrounding of the smaller area positive electrode active layer, but also compensate for the size difference between the positive and negative electrodes, providing support for the negative electrode in the subsequent roll pressing and compounding process, so that the size of the positive and negative pole pieces is consistent, and the short circuit problem caused by the edge shear stress during pressing is eliminated. On this basis, the roll pressing and compounding can effectively improve the densification and improve the electrolyte interface contact. The manufacturing method is simple, convenient, economical and efficient, and is suitable for mass production.

[0008] To achieve this purpose, the present application adopts the following technical solutions:

[0009] In a first aspect, the present application provides a manufacturing method of a battery cell structure, comprising:

[0010] Forming a plurality of positive electrode insulation partitions spaced apart on the to-be-coated surface of the positive electrode current collector in the unwinding direction, and forming a positive electrode active layer in the region between every two adjacent positive electrode insulation partitions, to obtain a positive electrode roll;

[0011] providing a negative electrode roll and a solid-state electrolyte membrane roll, unwinding the positive electrode roll, the negative electrode roll and the solid-state electrolyte membrane roll, and performing roll pressing and compounding according to the layer structure of negative electrode pole piece / solid-state electrolyte membrane / positive electrode pole piece, to obtain a composite electrode roll;

[0012] The composite electrode roll is cut, and the cutting position of the piece is located in the positive electrode insulation partition, to obtain a battery structure.

[0013] The present application can insulate the smaller area of the positive active layer around, compensate for the difference between the positive and negative electrodes, and provide support for the negative electrode during the subsequent roll compounding. On this basis, the roll compounding process is used to replace the existing isostatic pressing process, which can effectively improve the densification and improve the electrolyte interface contact, and make the positive and negative electrode sheet size consistent to avoid or eliminate the short circuit caused by the edge shear stress during pressing. Compared with the prior art of manufacturing cut positive and negative electrode sheets and electrolyte films, and then stacking, hot pressing and isostatic pressing, the present application does not need to be cut first, but by preparing a positive electrode roll, a negative electrode roll and a solid electrolyte film roll, and then roll compounding to obtain a composite electrode roll, and then cutting the composite electrode roll by setting the positive electrode insulation partition, the process is relatively simplified, the manufacturing method is simple and convenient, economic and efficient, and the manufacturing efficiency and yield are further improved, which is suitable for continuous mass production.

[0014] The following is a preferred technical solution of the present application, but not as a limitation of the technical solutions provided by the present application. Through the following technical solutions, the technical purposes and beneficial effects of the present application can be better achieved and realized.

[0015] As a preferred technical solution of the present application, the method for preparing the negative electrode roll comprises: continuously and uninterruptedly coating the negative active layer on the unwound negative current collector to obtain a negative electrode roll.

[0016] Alternatively, along the unwinding direction, a plurality of negative insulation partitions corresponding one-to-one to the positive insulation partitions are formed on the to-be-coated surface of the negative current collector in a spaced arrangement, and the negative active layer corresponding one-to-one to the positive active layer is formed in the region between every two adjacent negative insulation partitions to obtain a negative electrode roll. The size of the negative insulation partition in the unwinding direction is smaller than that of the corresponding positive insulation partition, and the size of the negative active layer in the unwinding direction is larger than that of the corresponding positive active layer.

[0017] Preferably, the size of the negative active layer in the unwinding direction is 2-6mm larger than that of the corresponding positive active layer.

[0018] Preferably, the size of the positive insulation partition in the unwinding direction is 1-20mm, and the thickness is 30-300μm.

[0019] Preferably, the size of the negative insulation partition in the unwinding direction is 2-6mm smaller than that of the corresponding positive insulation partition, and the thickness is 30-300μm.

[0020] Preferably, the thickness of the positive electrode insulating partition is equal to the thickness of the positive electrode active layer.

[0021] Preferably, the thickness of the negative electrode insulating partition is equal to the thickness of the negative electrode active layer.

[0022] Preferably, during the roll-pressing composite, the composite position is controlled so that the edge of the negative electrode active layer along the unwinding direction exceeds the edge of the corresponding positive electrode active layer and falls onto the positive electrode insulating partition, and the edge of the negative electrode insulating partition along the unwinding direction does not exceed the edge of the corresponding positive electrode insulating partition.

[0023] Preferably, the cutting slice positions are located in the positive electrode insulation partition and the negative electrode insulation partition.

[0024] Preferably, after the cutting, the remaining size of the positive electrode insulation partition and / or the negative electrode insulation partition in the battery core structure in the unwinding direction is 0.5 to 5 mm.

[0025] As a preferred technical solution of the present invention, in a direction perpendicular to the unwinding direction, both ends of all positive insulating partitions are respectively connected to corresponding positive insulating edges, and the positive insulating edges and the positive insulating partitions constitute a positive insulating frame.

[0026] Preferably, in the direction perpendicular to the unwinding direction, both ends of all negative electrode insulating partitions are respectively connected to the corresponding negative electrode insulating edges, and the negative electrode insulating edges and the negative electrode insulating partitions constitute a negative electrode insulating frame; the size of the negative electrode insulating edge in the direction perpendicular to the unwinding direction is smaller than that of the corresponding positive electrode insulating edge, and at the same time, the size of the negative electrode active layer in the direction perpendicular to the unwinding direction is larger than that of the corresponding positive electrode active layer.

[0027] Preferably, the dimension of the negative electrode active layer in the direction perpendicular to the unwinding direction is 2 to 6 mm larger than that of the corresponding positive electrode active layer.

[0028] Preferably, the size of the positive electrode insulating edge in the direction perpendicular to the unwinding direction is 1 to 20 mm, and the thickness is 30 to 300 μm.

[0029] Preferably, the dimension of the negative electrode insulating edge in the direction perpendicular to the unwinding direction is 2 to 6 mm smaller than that of the corresponding positive electrode insulating partition, and the thickness is 30 to 300 μm.

[0030] Preferably, the thickness of the positive electrode insulating edge is equal to the thickness of the positive electrode insulating partition.

[0031] Preferably, the thickness of the negative electrode insulating edge is equal to the thickness of the negative electrode insulating partition.

[0032] Preferably, during the roll-pressing composite, the composite position is controlled so that the edge of the negative electrode active layer along the direction perpendicular to the unwinding direction exceeds the edge of the corresponding positive electrode active layer and falls onto the positive electrode insulating edge, and the edge of the negative electrode insulating edge along the direction perpendicular to the unwinding direction does not exceed the edge of the corresponding positive electrode insulating edge.

[0033] Preferably, the cutting further includes trimming the positive electrode insulating edge and / or the negative electrode insulating edge. After the cutting, the remaining size of the positive electrode insulating edge and / or the negative electrode insulating edge perpendicular to the unwinding direction is 0.5 to 5 mm.

[0034] As a preferred technical solution of the present invention, when forming the negative electrode active layer, the edges of the negative electrode active layer and the negative electrodes on both sides are controlled to be insulated and separated to retain a negative electrode buffer gap.

[0035] Preferably, the size of the negative electrode buffer gap is ≤0.3 mm.

[0036] Preferably, when forming the positive electrode active layer, the edges of the positive electrode active layer that are insulated from the positive electrodes on both sides are controlled to retain a positive electrode buffer gap.

[0037] Preferably, the size of the positive electrode buffer gap is ≤0.3 mm.

[0038] As a preferred technical solution of the present invention, the method for forming the positive electrode insulation partition or the negative electrode insulation partition includes: preparing an insulation slurry with an insulation slurry, a binder and a solvent; and applying and drying the insulation slurry.

[0039] Preferably, the insulating material comprises boehmite and / or aluminum oxide.

[0040] Preferably, the binder includes at least one of polyvinyl alcohol, polyacrylic acid, polyvinylidene fluoride, styrene-butadiene rubber or carboxymethyl cellulose.

[0041] Preferably, the solvent comprises N-methylpyrrolidone and / or pure water.

[0042] Preferably, based on the total mass of the insulating material and the adhesive being 100%, the insulating material accounts for 50% to 95%, and the adhesive accounts for 5% to 50%.

[0043] Preferably, the solid content of the insulating slurry is 5% to 70%.

[0044] Preferably, the coating method comprises gravure coating.

[0045] As a preferred technical solution of the present invention, before the roll-pressing composite, the total thickness of the layer structure of the negative electrode sheet / solid electrolyte membrane / positive electrode sheet is recorded as H0; the effective rolling width of the layer structure by the roll-pressing composite is recorded as W, the roller diameter is recorded as D, and the rolling pressure is recorded as F; the pressure borne by the layer structure during the roll-pressing composite is recorded as P; after the roll-pressing composite is performed, the thickness of the layer structure is recorded as H1, then:

[0046]

[0047] The units of H0, H1, W, and D are mm, the unit of F is T, and the unit of P is Pa.

[0048] Preferably, P≤3GPa.

[0049] In a second aspect, the present invention provides a battery cell structure, which is obtained according to the manufacturing method described in the first aspect of the claim.

[0050] In a third aspect, the present invention provides an all-solid-state battery comprising the battery cell structure described in the second aspect.

[0051] In a fourth aspect, the present invention provides a method for manufacturing the all-solid-state battery described in the third aspect, the manufacturing method comprising: stacking, hot pressing, vacuum packaging with aluminum-plastic film, and chemically dividing the battery cell structure described in the second aspect in sequence to obtain an all-solid-state battery.

[0052] As a preferred technical solution of the present invention, the temperature of the hot pressing is 60-120° C., the pressure is 3-10T, and the time is 60-180s.

[0053] It should be noted that due to space limitations and to avoid redundancy, the present invention does not exhaustively list all point values ​​within the above numerical range, but is not limited to the listed values. Other unlisted values ​​within the above numerical range are also applicable.

[0054] Compared with the existing technical solutions, the present invention has at least the following beneficial effects:

[0055] The present invention provides a positive electrode insulation partition on the surface of the positive electrode current collector, which can not only insulate the smaller area around the positive electrode active layer, but also compensate for the difference in the size of the positive and negative electrodes, providing support for the negative electrode in the subsequent composite. On this basis, by using a roller-pressing composite process to replace the isostatic pressing process in the technology, it can not only effectively improve densification and improve the electrolyte interface contact, but also make the positive and negative electrode sheets consistent in size, thereby avoiding or eliminating problems such as short circuits caused by edge shear stress during pressure application. The manufacturing method is simple, convenient, economical and efficient, and further improves manufacturing efficiency and yield, making it suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a schematic diagram of the surface of the rolled positive electrode obtained in Example 1 after it is unfolded.

[0057] Figure 2 This is a schematic diagram of the surface of the negative electrode roll obtained in Example 1 after it is unfolded.

[0058] Figure 3 yes Figure 1 Schematic diagram of the cross section along the AA direction.

[0059] Figure 4 yes Figure 2 Schematic diagram of the cross section along the AA direction.

[0060] Figures 1 to 4 Middle: 10-positive electrode current collector, 11-positive electrode insulating partition, 12-positive electrode active layer, 13-positive electrode insulating edge, 20-negative electrode current collector, 21-negative electrode insulating partition, 22-negative electrode active layer, 23-negative electrode insulating edge.

[0061] Figure 5 Schematic diagram of the system device used for roll lamination in Example 1.

[0062] Figure 6 Schematic diagram of the force acting on the cell structure during roll-compression lamination in Example 1.

[0063] Figure 5 and Figure 6 Middle: 31-positive electrode unwinding roller, 32-negative electrode unwinding roller, 33-solid electrolyte membrane unwinding roller, 34-auxiliary roller, 35-roller press, 36-composite electrode winding roller. DETAILED DESCRIPTION

[0064] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0065] It should be apparent to those skilled in the art that the embodiments are only intended to help understand the present invention and should not be considered as specific limitations of the present invention.

[0066] In some specific embodiments, the present invention provides a method for manufacturing a battery core structure, the manufacturing method comprising:

[0067] Along the unwinding direction, a plurality of positive electrode insulating partitions are formed on the surface to be coated of the positive electrode current collector at intervals, and a positive electrode active layer is formed in the area between every two adjacent positive electrode insulating partitions to obtain a positive electrode roll;

[0068] Providing a negative electrode coil and a solid electrolyte membrane coil, unwinding the positive electrode coil, the negative electrode coil and the solid electrolyte membrane coil, and rolling and compounding them according to the layer structure of negative electrode sheet / solid electrolyte membrane / positive electrode sheet to obtain a composite electrode coil;

[0069] The composite electrode coil is cut, and the cutting position is located in the positive electrode insulating partition to obtain a battery core structure.

[0070] In one embodiment, the method for preparing the negative electrode roll includes: continuously and uninterruptedly coating a negative electrode active layer on an unwound negative electrode current collector to obtain a negative electrode roll.

[0071] In the present invention, the positive electrode insulating partition is provided on the positive electrode current collector, and a positive electrode active layer is formed between the partitions, so that the continuously coated positive electrode active layer is adjusted to an intermittent coating, so that the area of ​​each positive electrode active layer is reduced compared with the continuously coated negative electrode active layer, meeting the requirement that the negative electrode sheet is larger than the positive electrode sheet in size; at this time, there are positive electrode insulating partitions on both sides (referring to the left and right sides) of each positive electrode active layer along the unwinding direction, so relative to each positive electrode active layer, the excess part of the negative electrode active layer can be carried on the surface of the positive electrode insulating partition on both sides, and then generate force interaction with the positive electrode insulating partition in the subsequent composite process. The positive electrode insulating partition makes up for the size difference between the positive and negative electrode sheets, provides support for the composite of the edges of the negative electrode sheet, thereby avoiding a series of process problems caused by the shear stress generated by the composite, and can ensure the insulation between the edges of the positive electrode active layer and the negative electrode active layer, further effectively avoiding the occurrence of short circuit.

[0072] It is understandable that the provision of the positive electrode insulating partition on the positive electrode current collector is based on the fact that the industry generally makes the size of the negative electrode active layer larger than the size of the positive electrode active layer, that is, the edge of the negative electrode active layer extends beyond the edge of the positive electrode active layer. If the positive electrode insulating partition is not provided on the positive electrode current collector, and it is continuously coated and the size is kept the same as the continuously coated negative electrode active layer, although there is no thickness difference and naturally no shear stress, it is very easy to cause subsequent lithium deposition and short circuit at the edge of the negative electrode; therefore, the provision of the positive electrode insulating partition on the positive electrode current collector is very beneficial to the electrode composite process and the manufacturing quality and performance level of the resulting battery cell structure.

[0073] On the basis of setting up the positive electrode insulation partition, since it provides an improvement and support effect on the composite process, the present invention further uses a roller composite process to realize the composite of the layer structure, which can not only achieve densification, but also improve production efficiency as a continuous preparation. Of course, the positive electrode coil with a positive electrode insulation partition can also be cut and stacked with the cut negative electrode sheet and solid electrolyte membrane and then subjected to conventional composite processes such as isostatic pressing, which can also avoid destructive shear stress. However, such an operation process is cumbersome and inefficient, and has strict requirements on the composite equipment, which is not conducive to continuous production. In these aspects, it is not as good as the roller composite processing process described in the present invention.

[0074] In one embodiment, along the unwinding direction, a plurality of negative electrode insulating partitions are formed on the surface to be coated of the negative electrode current collector, which are arranged at intervals and correspond one-to-one to the positive electrode insulating partitions, and a negative electrode active layer is formed in the area between every two adjacent negative electrode insulating partitions and corresponds one-to-one to the positive electrode active layer to obtain a negative electrode roll; and the size of the negative electrode insulating partition in the unwinding direction is smaller than the corresponding positive electrode insulating partition, and the size of the negative electrode active layer in the unwinding direction is larger than the corresponding positive electrode active layer.

[0075] It is understandable that in addition to the continuous coating of the negative electrode sheet, a corresponding negative electrode insulating partition can also be set in the negative electrode, so that the negative electrode active layer is also adjusted to the corresponding intermittent coating state. At this time, it should be ensured that the size of each negative electrode active layer is larger than the size of the corresponding positive electrode active layer. This difference in size especially refers to the coating length of each active layer along the unwinding direction and the length of the formed active layer. Therefore, at this time, the size (i.e., width) of the negative electrode insulating partition in the unwinding direction should also be smaller than the size of the positive electrode insulating partition in the unwinding direction, so as to ensure that the middle part of each positive electrode insulating partition takes over the negative electrode insulating partition, and the two side parts take over the edges of the two negative electrode active layers respectively.

[0076] In one embodiment, the size of the negative electrode active layer in the unwinding direction is 2 to 6 mm larger than that of the corresponding positive electrode active layer, for example, it can be 2 mm, 2.3 mm, 2.5 mm, 2.8 mm, 3 mm, 3.3 mm, 3.5 mm, 3.8 mm, 4 mm, 4.2 mm, 4.4 mm, 4.6 mm, 4.8 mm, 5 mm, 5.2 mm, 5.4 mm, 5.6 mm, 5.8 mm or 6 mm, etc.

[0077] In one embodiment, the size of the positive electrode insulating partition in the unwinding direction is 1 to 20 mm, for example, it can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm or 20 mm, etc.; the thickness is 30 to 300 μm, for example, it can be 30 μm, 50 μm, 80 μm, 100 μm, 130 μm, 150 μm, 180 μm, 200 μm, 230 μm, 250 μm, 280 μm or 300 μm, etc.

[0078] In one embodiment, the size of the negative electrode insulating partition in the unwinding direction is 2 to 6 mm smaller than the corresponding positive electrode insulating partition, for example, it can be 2 mm, 2.3 mm, 2.5 mm, 2.8 mm, 3 mm, 3.3 mm, 3.5 mm, 3.8 mm, 4 mm, 4.2 mm, 4.4 mm, 4.6 mm, 4.8 mm, 5 mm, 5.2 mm, 5.4 mm, 5.6 mm, 5.8 mm or 6 mm, etc.; the thickness is 30 to 300 μm, for example, it can be 30 μm, 50 μm, 80 μm, 100 μm, 130 μm, 150 μm, 180 μm, 200 μm, 230 μm, 250 μm, 280 μm or 300 μm, etc.

[0079] In one embodiment, the thickness of the positive electrode insulating partition is equal to the thickness of the positive electrode active layer.

[0080] In one embodiment, the thickness of the negative electrode insulating partition is equal to the thickness of the negative electrode active layer.

[0081] In one embodiment, during the roll-pressing composite, the composite position of the negative electrode sheet and the positive electrode sheet is controlled so that the edge of the negative electrode active layer along the unwinding direction exceeds the edge of the corresponding positive electrode active layer and falls into the positive electrode insulating partition, and the edge of the negative electrode insulating partition along the unwinding direction does not exceed the edge of the corresponding positive electrode insulating partition.

[0082] In one embodiment, the cut slices are located in the positive electrode insulation partition and the negative electrode insulation partition.

[0083] It should be noted that when the battery cell structure contains both the positive electrode insulating partition and the negative electrode insulating partition, in order to avoid cutting the slices into the positive electrode active layer and the negative electrode active layer, the most suitable slicing position should be determined in the overlapping area of ​​the positive electrode insulating partition and the negative electrode insulating partition's positive projection onto the solid electrolyte membrane.

[0084] In one embodiment, after cutting, the remaining width of the positive electrode insulation partition or the negative electrode insulation partition in the battery cell structure is 0.5 to 5 mm, for example, it can be 0.5 mm, 0.8 mm, 1 mm, 1.3 mm, 1.5 mm, 1.8 mm, 2 mm, 2.3 mm, 2.5 mm, 2.8 mm, 3 mm, 3.3 mm, 3.5 mm, 3.8 mm, 4 mm, 4.2 mm, 4.5 mm, 4.8 mm or 5 mm, etc.

[0085] In one embodiment, in a direction perpendicular to the unwinding direction, both ends of all positive electrode insulating partitions are respectively connected to corresponding positive electrode insulating edges, and the positive electrode insulating edges and the positive electrode insulating partitions constitute a positive electrode insulating frame.

[0086] In one embodiment, in a direction perpendicular to the unwinding direction, both ends of all negative electrode insulating partitions are respectively connected to corresponding negative electrode insulating edges, and the negative electrode insulating edges and the negative electrode insulating partitions constitute a negative electrode insulating frame; the size of the negative electrode insulating edge in the direction perpendicular to the unwinding direction is smaller than that of the corresponding positive electrode insulating edge, and at the same time, the size of the negative electrode active layer in the direction perpendicular to the unwinding direction is larger than that of the corresponding positive electrode active layer.

[0087] Taking into account that the size of the positive electrode active layer and the negative electrode active layer are usually kept the same in the coating width (referring to the size perpendicular to the unwinding direction), the basic concept of the present invention is to set an insulating partition in the coating length direction. Furthermore, of course, it is also possible to make the size of each negative electrode active layer larger than the corresponding size of each positive electrode active layer in the coating width direction as needed. In this case, it is necessary to set a corresponding insulating part, that is, the insulating edge. The insulating edge is provided on both sides of each active layer perpendicular to the unwinding direction (i.e., the upper side and the lower side), and the upper and lower insulating edges connect the two ends of the insulating partition on the left and right sides of each active layer to form a frame with an outer contour shape feature (such as a rectangle), and multiple frames are arranged end to end along the unwinding direction, which is equivalent to forming a network (grid) of insulating frames on the current collector, and the active layer fills the blank parts of the grid (coating area) one by one. It can be understood that, similar to the relationship between the positive electrode insulation partition and the negative electrode insulation partition, the size of the negative electrode insulation edge in the direction perpendicular to the unwinding direction should be smaller than the corresponding positive electrode insulation edge to ensure that the positive electrode insulation edge can receive the edge of the negative electrode active layer in the direction perpendicular to the unwinding direction.

[0088] After understanding the purpose of the above-mentioned insulating partitions and insulating frames, further, the widths of the positive insulating partitions on the left and right sides of each positive active layer may not be equal, but they must still meet the appropriate dimensional relationship with the widths of the negative insulating partitions on the left and right sides of the corresponding negative active layer. Similarly, the widths of the positive insulating edges on the upper and lower sides of each positive active layer may be different, but they must still meet the appropriate dimensional relationship with the widths of the negative insulating edges on the upper and lower sides of the corresponding negative active layer. Furthermore, the frame shape of each positive insulating frame and the corresponding negative insulating frame can not only be rectangular, but can also be adjusted to square, parallelogram, or even triangular and elliptical frames according to design and needs.

[0089] In one embodiment, the size of the negative electrode active layer in the direction perpendicular to the unwinding direction is 2 to 6 mm larger than the corresponding positive electrode active layer, for example, it can be 2 mm, 2.3 mm, 2.5 mm, 2.8 mm, 3 mm, 3.3 mm, 3.5 mm, 3.8 mm, 4 mm, 4.2 mm, 4.4 mm, 4.6 mm, 4.8 mm, 5 mm, 5.2 mm, 5.4 mm, 5.6 mm, 5.8 mm or 6 mm, etc.

[0090] In one embodiment, the positive electrode insulation edge has a dimension in a direction perpendicular to the unwinding direction of 1-20 mm, for example 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, or 20 mm, etc.; and a thickness of 30-300 μm, for example 30 μm, 50 μm, 80 μm, 100 μm, 130 μm, 150 μm, 180 μm, 200 μm, 230 μm, 250 μm, 280 μm, or 300 μm, etc.

[0091] In one embodiment, the negative electrode insulation edge has a dimension in the unwinding direction of 2-6 mm less than the corresponding positive electrode insulation partition, for example 2 mm, 2.3 mm, 2.5 mm, 2.8 mm, 3 mm, 3.3 mm, 3.5 mm, 3.8 mm, 4 mm, 4.2 mm, 4.4 mm, 4.6 mm, 4.8 mm, 5 mm, 5.2 mm, 5.4 mm, 5.6 mm, 5.8 mm, or 6 mm, etc.; and a thickness of 30-300 μm, for example 30 μm, 50 μm, 80 μm, 100 μm, 130 μm, 150 μm, 180 μm, 200 μm, 230 μm, 250 μm, 280 μm, or 300 μm, etc.

[0092] In one embodiment, the thickness of the positive electrode insulation edge is equal to the thickness of the positive electrode insulation partition.

[0093] In one embodiment, the thickness of the negative electrode insulation edge is equal to the thickness of the negative electrode insulation partition.

[0094] In one embodiment, in the roll-to-roll compounding, the compounding position is controlled so that the edge of the negative electrode active layer in a direction perpendicular to the unwinding direction exceeds the edge of the corresponding positive electrode active layer and falls into the positive electrode insulation edge, and the edge of the negative electrode insulation edge in a direction perpendicular to the unwinding direction does not exceed the edge of the corresponding positive electrode insulation edge.

[0095] In one embodiment, the cutting further comprises trimming the positive electrode insulation edge and / or the negative electrode insulation edge, and after the cutting, the remaining dimension of the positive electrode insulation edge and / or the negative electrode insulation edge in a direction perpendicular to the unwinding direction is 0.5-5 mm, for example 0.5 mm, 0.8 mm, 1 mm, 1.3 mm, 1.5 mm, 1.8 mm, 2 mm, 2.3 mm, 2.5 mm, 2.8 mm, 3 mm, 3.3 mm, 3.5 mm, 3.8 mm, 4 mm, 4.2 mm, 4.5 mm, 4.8 mm, or 5 mm, etc.

[0096] In one embodiment, the cutting equipment includes a metal die-cutting machine or a laser die-cutting machine, and the dimensional accuracy of the cutting is controlled to not exceed ±0.1 mm.

[0097] In one embodiment, when forming the negative electrode active layer, the edges of the negative electrode active layer that are insulated from the negative electrodes on both sides are controlled to retain a negative electrode buffer gap.

[0098] In one embodiment, the size of the negative electrode buffer gap is ≤0.3 mm, for example, it can be 0.05 mm, 0.1 mm, 0.13 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.25 mm, 0.28 mm or 0.3 mm.

[0099] In one embodiment, when forming the positive electrode active layer, the edges of the positive electrode active layer that are insulated and separated from the positive electrodes on both sides are controlled to retain a positive electrode buffer gap.

[0100] In one embodiment, the size of the positive electrode buffer gap is ≤0.3 mm, for example, it can be 0.05 mm, 0.1 mm, 0.13 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.25 mm, 0.28 mm or 0.3 mm.

[0101] It should be noted that, considering that the porosity of the positive electrode active coating and the negative electrode active coating is greater than that of the insulating partition, the insulating edge and the insulating frame, the compression ratio is greater, and the thickness of the active layer during coating can even be greater than the thickness of the insulating partition, so as to facilitate the subsequent full compression of the active layer to form an active layer that meets the compaction density requirements. In order to facilitate the extension and compression of the active layer and avoid the active layer overlapping with the insulating frame after extension during subsequent roller pressing and compounding, the present invention reserves sufficient extension space by setting a buffer gap. It should be noted that even if the positive electrode buffer gap is set, it should be ensured that the edge of the negative electrode active layer in the unwinding direction can fall onto the positive electrode insulating partition, rather than falling into the positive electrode buffer gap; similarly, when the negative electrode buffer gap is set, the edge of the adjacent negative electrode insulating partition in the unwinding direction should also be kept within the edge of the corresponding positive electrode insulating partition, so as to ensure that the positive electrode insulating partition has sufficient effective position (area) to receive the negative electrode active layers on both sides.

[0102] In one embodiment, the dimensional accuracy of the positive electrode insulation partition, the negative electrode insulation partition, the positive electrode insulation edge and the negative electrode insulation edge is controlled, wherein the accuracy of the width does not exceed ±0.1 mm, and the accuracy of the thickness does not exceed ±0.5 μm.

[0103] In one embodiment, the method for manufacturing the battery core structure is performed at an ambient dew point of ≤-60°C.

[0104] In one embodiment, the method of forming the positive electrode insulation partition or the negative electrode insulation partition comprises: formulating an insulation paste, a binder and a solvent into an insulation paste; coating using the insulation paste and drying.

[0105] In one embodiment, the insulation material comprises boehmite and / or aluminum trioxide.

[0106] In one embodiment, the binder comprises at least one of polyvinyl alcohol (PVA), polyacrylic acid (PAA), polyvinylidene fluoride (PVDF), styrene butadiene rubber (SBR) or carboxymethyl cellulose (CMC).

[0107] In one embodiment, the solvent comprises N-methyl pyrrolidone (NMP) and / or pure water.

[0108] In one embodiment, the insulation material accounts for 50% to 95% and the binder accounts for 5% to 50%, for example, the insulation material can be 50%, 52%, 55%, 58%, 60%, 63%, 65%, 68%, 70%, 73%, 75%, 78%, 80%, 83%, 85%, 88%, 90%, 92% or 95%, etc., and the binder can be 5%, 8%, 10%, 12%, 15%, 18%, 20%, 25%, 28%, 30%, 33%, 35%, 38%, 40%, 42%, 45%, 48% or 50%, etc., based on the total mass of the insulation material and the binder being 100%.

[0109] In one embodiment, the solid content of the insulation paste is 5% to 70%, for example, it can be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65% or 70%, etc.

[0110] In one embodiment, the coating method comprises gravure coating.

[0111] The present application does not specifically limit the selection of the positive electrode current collector and the negative electrode current collector, and exemplary, the current collector comprises at least one of aluminum foil, copper foil, stainless steel foil or composite foil (such as carbon-coated aluminum foil, carbon-coated copper foil), which should be reasonably selected according to actual design and needs.

[0112] The present invention does not specifically limit the composition and formation method (coating method) of the positive electrode active layer and the negative electrode active layer. Usually, the active layer includes an active material, a conductive agent and a binder, and may also include a solid electrolyte or an additive for pre-lithiation; the method for forming the positive electrode active layer and the negative electrode active layer includes coating (such as extrusion coating) and drying the positive electrode slurry or the negative electrode slurry; the positive electrode slurry and the negative electrode slurry should also include solvents and other necessary components of the slurry. Furthermore, when coating, the slurry coating can be accurately controlled to fall into the coating area within the insulating frame through CCD detection (Charge-Coupled Device), coating gasket size design and control of the opening and closing time of the coating valve / reflux valve.

[0113] In one embodiment, the roller-combining equipment includes a roller press, the temperature of which can be adjusted in the range of room temperature (15-35°C) to 150°C, the pressure can be adjusted in the range of 0-100T, the roller diameter is 300-1000mm, the effective roller width is ≤1000mm, the roller gap working range is 0-5mm, and the operating speed is ≤50m / min; further, it is equipped with three sets of unwinding tension and correction control devices, one set of winding tension and correction control devices.

[0114] In one embodiment, Figure 5 As shown, in addition to the double-roller press 35, the system device for realizing the roller-compression composite of the battery cell structure also includes a positive electrode unwinding roller 31, a negative electrode unwinding roller 32, a solid electrolyte membrane unwinding roller 33, an auxiliary roller 34 arranged between each unwinding roller and the double-roller press, and a composite electrode winding roller 36 arranged after the double-roller press 35.

[0115] It is understandable that the manufacturing method of the battery cell structure of the present invention can realize a continuous unwinding and winding manufacturing process before the cutting and slicing is performed, that is, by unwinding the positive electrode current collector to form a positive electrode insulating partition (or further a positive electrode insulating frame) and forming a positive electrode active layer, it can be selected to be wound up to obtain a positive electrode coil, and then the positive electrode coil is unwound for subsequent roll-pressing and compounding; similarly, the negative electrode current collector can be continuously coated after unwinding to form a continuous negative electrode active layer, or after forming a negative electrode insulating partition (or further a negative electrode insulating frame) and a negative electrode active layer, it can be selected to be wound up to obtain a negative electrode coil, and then the negative electrode coil is unwound for subsequent roll-pressing and compounding. When the positive electrode coil and the negative electrode coil are unwound, the solid electrolyte membrane coil also needs to be unwound at the same time. After rolling and compounding, a layer structure of negative electrode sheet / solid electrolyte membrane / positive electrode sheet is formed. It can be selected to be wound up to obtain a composite electrode coil, and then unwound and cut to obtain individual battery cell structures.

[0116] It is understood that in the present invention, relative to each positive electrode active layer and the corresponding negative electrode active layer, the size of each corresponding solid electrolyte membrane should be greater than or equal to the positive electrode active layer and less than or equal to the negative electrode active layer.

[0117] In one embodiment, Figure 6 As shown, before the roll-pressing lamination, the total thickness of the layer structure of the negative electrode sheet / solid electrolyte membrane / positive electrode sheet is recorded as H0; the effective rolling width of the layer structure by the roll-pressing lamination is recorded as W, the roller diameter is recorded as D, and the rolling pressure is recorded as F; the pressure to which the layer structure is subjected during the roll-pressing lamination is recorded as P; after the roll-pressing lamination, the thickness of the layer structure is recorded as H1, then:

[0118]

[0119] The units of H0, H1, W, and D are mm, the unit of F is T, and the unit of P is Pa.

[0120] In one embodiment, the P≤3 GPa, for example, it can be 3 GPa, 2.9 GPa, 2.8 GPa, 2.7 GPa, 2.6 GPa, 2.5 GPa, 2.4 GPa, 2.3 GPa, 2.2 GPa, 2.1 GPa, 2 GPa, 1.9 GPa, 1.8 GPa, 1.7 GPa, 1.6 GPa, 1.5 GPa, 1.3 GPa, 1 GPa, 0.8 GPa, 0.5 GPa, 0.3 GPa or 0.1 GPa, etc.

[0121] It should be noted that the effective rolling width W must at least cover (greater than or equal to) the sum of the width of the positive electrode active layer in the positive electrode roll and the width of the positive electrode insulating frame (especially the positive electrode insulating edge), and / or the effective rolling width W must at least cover (greater than or equal to) the sum of the width of the negative electrode active layer in the negative electrode roll and the width of the negative electrode insulating frame (especially the negative electrode insulating edge), and / or the effective rolling width W must at least cover (greater than or equal to) the width of the solid electrolyte membrane (roll).

[0122] The present invention uses roll-to-roll lamination instead of conventional isostatic pressing technology, so that the layer structure in the roll-to-roll lamination can be subjected to a pressure of up to 3 GPa, which is much greater than the working pressure of isostatic pressing (≤0.8 GPa), and can fully achieve densification.

[0123] In some specific embodiments, the present invention provides a battery core structure, which is obtained according to the manufacturing method provided in the above embodiment.

[0124] In some specific embodiments, the present invention provides an all-solid-state battery comprising the battery cell structure described in the above embodiments.

[0125] In some specific embodiments, the present invention provides a method for manufacturing the all-solid-state battery described in the above embodiment, the manufacturing method comprising: stacking, hot pressing, vacuum packaging with aluminum-plastic film, and chemically dividing the battery cell structure provided in the above embodiment in sequence to obtain an all-solid-state battery.

[0126] In one embodiment, the hot pressing temperature is 60-120°C, for example, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C or 120°C, the pressure is 3-10T (tons), for example, 3T, 4T, 5T, 6T, 7T, 8T, 9T or 10T, and the time is 60-180s, for example, 60s, 70s, 80s, 90s, 100s, 110s, 120s, 130s, 140s, 150s, 160s, 170s or 180s, etc.

[0127] The battery cell structure obtained by roll-compounding according to the present invention is stacked and hot-pressed, thereby ensuring that the battery cell structure after hot-pressing is stable and will not be dislocated due to looseness.

[0128] Example 1

[0129] This embodiment provides a method for manufacturing a battery cell structure, the manufacturing method comprising:

[0130] (1) Preparation of slurry:

[0131] At an ambient dew point of ≤-60°C, 100g of boehmite (insulating material), 30g of polyvinylidene fluoride (PVDF) adhesive, and 250g of N-methylpyrrolidone (solvent) were added to a mixer at a stirring speed of 50 rpm and a dispersion speed of 3000 rpm. The mixture was uniformly mixed to form an insulating slurry for standby use. The slurry had a solid content of 34.2% and a viscosity of 500 MPa·s.

[0132] At the same time, providing or preparing positive electrode slurry, negative electrode slurry and sulfide solid electrolyte slurry;

[0133] (2) Preparation of positive electrode rolls, negative electrode rolls, and solid electrolyte membrane rolls:

[0134] like Figure 1 as well as Figure 3As shown, the aluminum foil of the positive electrode collector 10 is unwound, and the size of the aluminum foil in the direction perpendicular to the unwinding direction is the width w3 of the positive electrode collector 10, w3 = equal to 160mm, and the thickness is 12μm; a gravure coater is used to coat several positive electrode insulating frames on the aluminum foil at intervals along the unwinding direction, and then dried, and the coating speed is controlled to be 5m / min and the drying temperature is 120°C; the size of the positive electrode insulating partitions 11 on the left and right sides of the positive electrode insulating frame in the unwinding direction is width G1, G1 = 12mm, and the size of the positive electrode insulating edges 13 on the upper and lower sides of the positive electrode insulating frame in the direction perpendicular to the unwinding direction is width G3, G3 = 8mm; the blank part between each two adjacent positive electrode insulating partitions 11 is the positive electrode coating area, and the size of the positive electrode coating area in the unwinding direction is length L1, L1 = 284mm ; The distance between the outer edge of the positive electrode insulating edge 13 on the upper and lower sides of the positive electrode insulating frame and the outer edge of the aluminum foil is 20 mm, and the dimension of the positive electrode coating area perpendicular to the unwinding direction is width w1, w1 = 104 mm; the thickness of the positive electrode insulating frame after drying is h3, h3 = 200 μm; after the positive electrode insulating frame is formed, the positive electrode slurry is coated on the positive electrode coating area in the positive electrode insulating frame and dried to form a positive electrode active layer 12 with a thickness of h1, h1 = 200 μm, and the positive electrode coil is obtained by winding; the distance between the edge of the positive electrode active layer 12 and the inner edge of the positive electrode insulating frame is 0.2 mm (that is, a positive electrode buffer gap of 0.2 mm is retained). Since this buffer gap is too small, it is not shown in the figure, but the positive electrode buffer gap is filled by the extended positive electrode active layer 12 in the subsequent roll-pressing composite;

[0135] At the same time, if Figure 2 as well as Figure 4As shown, the copper foil of the negative electrode current collector 20 is unwound, and the dimension of the copper foil in the direction perpendicular to the unwinding direction is the width w4 of the negative electrode current collector 20, w4=160mm, and the thickness is 6μm; a gravure coater is used to coat a number of negative electrode insulating frames on the copper foil at intervals along the unwinding direction, and then dried, and the coating speed is controlled to be 5m / min and the drying temperature is 120°C; the dimension of the negative electrode insulating partitions 21 on the left and right sides of the negative electrode insulating frame in the unwinding direction is a width G2, G2=4mm, and the dimension of the positive electrode insulating edges 13 on the upper and lower sides of the negative electrode insulating frame in the direction perpendicular to the unwinding direction is a width G4, G4=4mm; the blank area between each two adjacent negative electrode insulating partitions 21 is the negative electrode coating area, and the dimension of the negative electrode coating area in the unwinding direction is a length L2, L2=292mm; The distance between the outer edge of the negative electrode insulating edge 23 on the upper and lower sides of the negative electrode insulating frame and the outer edge of the aluminum foil is 20 mm, that is, the dimension of the negative electrode coating area in the direction perpendicular to the unwinding direction is width w2, w2 = 112 mm; the thickness of the negative electrode insulating frame after drying is h4, h4 = 70 μm; after the negative electrode insulating frame is formed, the negative electrode slurry is coated on the negative electrode coating area in the negative electrode insulating frame, and the negative electrode active layer 22 formed after drying has a thickness of h2, h2 = 70 μm, and the negative electrode coil is obtained by winding; the distance between the edge of the negative electrode active layer 22 and the inner edge of the negative electrode insulating frame is 0.2 mm (that is, a negative electrode buffer gap of 0.2 mm is retained). Since this buffer gap is too small, it is not shown in the figure, but the negative electrode buffer gap is filled by the extended negative electrode active layer 22 in the subsequent roll-pressing composite;

[0136] At the same time, the sulfide solid electrolyte slurry is coated and dried to obtain a solid electrolyte membrane with a thickness of 100 μm, which is then rolled up to obtain a solid electrolyte membrane roll;

[0137] (3) Roller lamination:

[0138] use Figure 5 The system device for implementing roll-combination shown in the figure unwinds the positive electrode coil, solid electrolyte membrane coil and negative electrode coil in the upper, middle and lower unwinding positions in turn through the positive electrode unwinding roller 31, the negative electrode unwinding roller 32 and the solid electrolyte membrane unwinding roller 33, and is assisted by the auxiliary roller 34 to be passed to the roller press 35, and roll-combined according to the layer structure of the negative electrode sheet / solid electrolyte membrane / positive electrode sheet, and then wound by the composite electrode winding roller. The roller diameter D of the roller in the roller press is 400 mm, the effective rolling width is recorded as W = w1 + 2 × G3 = w2 + 2 × G4 = 120 mm, the temperature is set to 100 ° C, the rolling pressure F = 100T, the rolling speed is 20 m / min, the total thickness of the layer structure before roll-combination is H0 = 388 μm, and the thickness of the layer structure formed after rolling is expected to be H1 = 230 μm; after rolling, the composite electrode coil is obtained; according to the following formula:

[0139]

[0140] The calculated pressure P to which the layer structure is subjected during the roll-combination process is 1.09 GPa.

[0141] (4) Cutting:

[0142] The composite electrode coil is unwound and cut using a hardware die-cutting machine. The slicing position is at the center of the overlapping area of ​​the positive electrode insulating partition 11 and the negative electrode insulating partition 21 to obtain the cut battery cell structures, wherein the battery cell structure has a length of 292 mm, a width of 112 mm, a tab width of 58 mm, and a tab height of 25 mm.

[0143] This embodiment also provides a method for manufacturing an all-solid-state battery, the method comprising:

[0144] (5) The cut cell structures are stacked to form a stacked structure of negative electrode sheet / electrolyte membrane / positive electrode sheet / electrolyte membrane / negative electrode sheet. The stacked cells are hot pressed using a flat hot press at a temperature of 90°C, a time of 120s, and a pressure of 5T. The hot pressed cells are vacuum packaged using an aluminum plastic film and finally subjected to chemical conversion under high pressure and high temperature in an atmospheric environment to obtain an all-solid-state battery.

[0145] In Example 1, 50 pieces of all-solid-state batteries were trial-produced, and 1 piece was found to be short-circuited during the formation test, with a short-circuit rate of 2%. The total time for the cell structure roll-combination process was ≤30 minutes.

[0146] Comparative Example 1

[0147] This comparative example provides a method for manufacturing an all-solid-state battery, the method comprising:

[0148] (1) Providing or preparing a positive electrode slurry, a negative electrode slurry, and a sulfide solid electrolyte slurry according to the method of Example 1;

[0149] (2) The positive electrode slurry was continuously coated on the aluminum foil, and the negative electrode slurry was continuously coated on the copper foil, and the width of the positive electrode active layer was controlled to be 108 mm and 116 mm respectively in the direction perpendicular to the unwinding direction; the positive electrode roll and the negative electrode roll were obtained by winding, which were compared with the solid electrolyte membrane roll of Example 1.

[0150] (3) unwinding the positive electrode roll and the negative electrode roll, and cutting the positive electrode sheet and the negative electrode sheet by using a hardware die-cutting machine; wherein the positive electrode sheet is cut into a sheet length of 284 mm in the unwinding direction, a sheet width of 104 mm in the direction perpendicular to the unwinding direction, an ear width of 58 mm, and an ear height of 25 mm; the negative electrode sheet is cut into a sheet length of 292 mm in the unwinding direction, a sheet width of 112 mm in the direction perpendicular to the unwinding direction, an ear width of 58 mm, and an ear height of 26 mm; and the solid-state electrolyte film roll is unwound and cut to obtain a solid-state electrolyte film sheet;

[0151] (4) stacking the cut positive electrode sheet, the negative electrode sheet, and the solid-state electrolyte film sheet to form a laminated structure of negative electrode sheet / electrolyte film / positive electrode sheet / electrolyte film / negative electrode sheet, the outer edges of the negative electrode sheet and the solid-state electrolyte film sheet are aligned, and the outer edge of the positive electrode sheet is inwardly recessed by 4 mm from the outer edge of the negative electrode sheet, that is, the positive electrode sheet is completely projected onto the negative electrode sheet, the stacked cell is hot-pressed by using a flat plate hot press, the hot-pressing temperature is 90℃, the time is 120s, and the pressure is 5T, and the hot-pressed cell is vacuum sealed by using an aluminum plastic film.

[0152] (5) performing isostatic pressing treatment on the sealed cell unit, the isostatic pressing pressure is 300MPa, the time is 30min, and the compacted solid-state cell is obtained by six-face pressing. The cell is re-packaged by using an aluminum plastic film under negative pressure in an environment with a dew point of ≤-60℃ to isolate the external environment, and finally, the solid-state battery is obtained by formation and capacity test under high pressure and high temperature in an atmospheric environment.

[0153] In the comparative example 1, 50pcs of the solid-state battery were trial-produced, 30pcs of which were found to be short-circuited in the formation test, and the short-circuit rate reached 60%, the isostatic pressing process of the cell took 10pcs of time for one pressing and 1H, and the whole trial production took 5H.

[0154] As can be seen from the above, by using the insulation partition or the insulation frame, the isostatic pressing process of the prior art can be completely replaced by the roll pressing composite process, and the problem of low production efficiency and high short-circuit rate of the cell caused by the isostatic pressing process of the solid-state battery is solved. In the manufacturing method of the cell structure and the manufacturing method of the solid-state battery, the roll pressing process under the cooperation of the insulation frame can realize greater working pressure and higher production efficiency, the battery short-circuit rate is reduced from at least 50% to less than 5%, the maximum pressure can be increased by at least 3.75 times, the efficiency can be increased by at least 10 times, and the production feasibility is further improved.

[0155] The preferred embodiments of the present application are described in detail above, but the present application is not limited to the specific details in the above-described embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0156] It should be further noted that any technically feasible combination of the various technical features described in the above embodiments is possible, provided that there is no contradiction, and the disclosure of the present application should be deemed to include all such technically feasible combinations.

[0157] Furthermore, any combination of the various embodiments of the present application is possible, provided that there is no contradiction, and the disclosure of the present application should be deemed to include all such technically feasible combinations.

Claims

1. A method for manufacturing a battery core structure, characterized in that: The manufacturing method comprises: Along the unwinding direction, a plurality of positive electrode insulating partitions are formed on the surface to be coated of the positive electrode current collector at intervals, and a positive electrode active layer is formed in the area between every two adjacent positive electrode insulating partitions to obtain a positive electrode roll; Providing a negative electrode coil and a solid electrolyte membrane coil, unwinding the positive electrode coil, the negative electrode coil and the solid electrolyte membrane coil, and rolling and compounding them according to the layer structure of negative electrode sheet / solid electrolyte membrane / positive electrode sheet to obtain a composite electrode coil; The composite electrode coil is cut, and the cutting position is located in the positive electrode insulating partition to obtain a battery core structure.

2. The method for manufacturing a battery core structure according to claim 1, wherein: The method for preparing the negative electrode coil comprises: continuously and uninterruptedly coating a negative electrode active layer on an unwound negative electrode current collector to obtain a negative electrode coil; Alternatively, a plurality of negative electrode insulating partitions are formed on the surface of the negative electrode current collector to be coated along the unwinding direction, and are arranged at intervals and correspond one-to-one to the positive electrode insulating partitions. A negative electrode active layer is formed in the region between every two adjacent negative electrode insulating partitions and corresponds one-to-one to the positive electrode active layer, to obtain a negative electrode coil; and the negative electrode insulating partition is smaller in size than the corresponding positive electrode insulating partition in the unwinding direction, and the negative electrode active layer is larger in size than the corresponding positive electrode active layer in the unwinding direction; Preferably, the size of the negative electrode active layer in the unwinding direction is 2 to 6 mm larger than that of the corresponding positive electrode active layer; Preferably, the positive electrode insulating partition has a size of 1 to 20 mm in the unwinding direction and a thickness of 30 to 300 μm; Preferably, the negative electrode insulating partition is 2 to 6 mm smaller in the unwinding direction than the corresponding positive electrode insulating partition, and has a thickness of 30 to 300 μm; Preferably, the thickness of the positive electrode insulating partition is equal to the thickness of the positive electrode active layer; Preferably, the thickness of the negative electrode insulating partition is equal to the thickness of the negative electrode active layer; Preferably, during the roll-pressing lamination, the lamination position is controlled so that the edge of the negative electrode active layer in the unwinding direction exceeds the edge of the corresponding positive electrode active layer and falls onto the positive electrode insulating partition, and the edge of the negative electrode insulating partition in the unwinding direction does not exceed the edge of the corresponding positive electrode insulating partition; Preferably, the cutting slices are located in the positive electrode insulation partition and the negative electrode insulation partition; Preferably, after the cutting, the remaining size of the positive electrode insulation partition and / or the negative electrode insulation partition in the battery core structure in the unwinding direction is 0.5 to 5 mm.

3. The method for manufacturing a battery core structure according to claim 2, wherein: In a direction perpendicular to the unwinding direction, both ends of all positive electrode insulation partitions are connected to corresponding positive electrode insulation edges, and the positive electrode insulation edges and the positive electrode insulation partitions form a positive electrode insulation frame; Preferably, in a direction perpendicular to the unwinding direction, both ends of all negative electrode insulating partitions are respectively connected to corresponding negative electrode insulating edges, and the negative electrode insulating edges and the negative electrode insulating partitions constitute a negative electrode insulating frame; the negative electrode insulating edges are smaller in size than the corresponding positive electrode insulating edges in the direction perpendicular to the unwinding direction, and the negative electrode active layer is larger in size than the corresponding positive electrode active layer in the direction perpendicular to the unwinding direction; Preferably, the dimension of the negative electrode active layer in the direction perpendicular to the unwinding direction is 2 to 6 mm larger than that of the corresponding positive electrode active layer; Preferably, the size of the positive electrode insulating edge in the direction perpendicular to the unwinding direction is 1 to 20 mm, and the thickness is 30 to 300 μm; Preferably, the dimension of the negative electrode insulation edge in the direction perpendicular to the unwinding direction is 2 to 6 mm smaller than the corresponding positive electrode insulation partition, and the thickness is 30 to 300 μm; Preferably, the thickness of the positive electrode insulating edge is equal to the thickness of the positive electrode insulating partition; Preferably, the thickness of the negative electrode insulating edge is equal to the thickness of the negative electrode insulating partition; Preferably, during the roll-pressing lamination, the lamination position is controlled so that the edge of the negative electrode active layer in the direction perpendicular to the unwinding direction exceeds the edge of the corresponding positive electrode active layer and falls onto the positive electrode insulating edge, and the edge of the negative electrode insulating edge in the direction perpendicular to the unwinding direction does not exceed the edge of the corresponding positive electrode insulating edge; Preferably, the cutting further includes trimming the positive electrode insulating edge and / or the negative electrode insulating edge. After the cutting, the remaining size of the positive electrode insulating edge and / or the negative electrode insulating edge perpendicular to the unwinding direction is 0.5 to 5 mm.

4. The method for manufacturing a battery core structure according to claim 2 or 3, wherein: When forming the negative electrode active layer, controlling the edges of the negative electrode active layer and the negative electrodes on both sides to be insulated and separated to retain a negative electrode buffer gap; Preferably, the size of the negative electrode buffer gap is ≤0.3 mm; Preferably, when forming the positive electrode active layer, the edges of the positive electrode active layer and the positive electrodes on both sides are controlled to retain a positive electrode buffer gap; Preferably, the size of the positive electrode buffer gap is ≤0.3 mm.

5. The method for manufacturing a battery core structure according to any one of claims 2 to 4, characterized in that: The method for forming the positive electrode insulation partition or the negative electrode insulation partition comprises: preparing an insulation slurry with an insulation slurry, a binder and a solvent; applying and drying the insulation slurry; Preferably, the insulating material comprises boehmite and / or aluminum oxide; Preferably, the binder comprises at least one of polyvinyl alcohol, polyacrylic acid, polyvinylidene fluoride, styrene-butadiene rubber or carboxymethyl cellulose; Preferably, the solvent comprises N-methylpyrrolidone and / or pure water; Preferably, based on the total mass of the insulating material and the adhesive being 100%, the insulating material accounts for 50% to 95%, and the adhesive accounts for 5% to 50%; Preferably, the solid content of the insulating paste is 5% to 70%; Preferably, the coating method comprises gravure coating.

6. The method for manufacturing a battery core structure according to any one of claims 2 to 5, characterized in that: Before the roll-pressing lamination, the total thickness of the layer structure of the negative electrode sheet / solid electrolyte membrane / positive electrode sheet is recorded as H0; the effective roll-pressing width of the layer structure by the roll-pressing lamination is recorded as W, the roller diameter is recorded as D, and the roll-pressing pressure is recorded as F; the pressure to which the layer structure is subjected during the roll-pressing lamination is recorded as P; after the roll-pressing lamination, the thickness of the layer structure is recorded as H1, then: Among them, the unit of H0, H1, W and D is mm, the unit of F is T, and the unit of P is Pa; Preferably, P≤3GPa.

7. A battery cell structure, characterized in that: Obtained according to the manufacturing method according to any one of claims 1 to 6.

8. An all-solid-state battery, characterized in that: Containing the battery cell structure according to claim 7.

9. A method for manufacturing an all-solid-state battery according to claim 8, characterized in that: The manufacturing method comprises: stacking, hot pressing, vacuum packaging with aluminum-plastic film, and chemically dividing the battery cell structure according to claim 7 in sequence to obtain an all-solid-state battery.

10. The method for manufacturing an all-solid-state battery according to claim 9, wherein: The temperature of the hot pressing is 60-120° C., the pressure is 3-10T, and the time is 60-180s.

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