Laminated lithium battery roll core structure as well as preparation process and preparation system thereof

Abstract

The invention relates to the technical field of lithium batteries, and particularly provides a laminated lithium battery roll core structure as well as a preparation process and a preparation system thereof. The roll core structure comprises a roll core left part, a liquid cooling plate, a roll core right part and an insulating film, the left part of the roll core is of a lamination structure formed by folding a left diaphragm according to a Z shape and alternately inserting left negative plates and left positive plates into the left diaphragm layer by layer; the right part of the roll core is of a lamination structure formed by folding a right diaphragm according to a Z shape and alternately inserting right negative plates and right positive plates into the right diaphragm layer by layer; and the insulating film is wrapped outside a laminated structure formed by the left part of the roll core, the liquid cooling plate and the right part of the roll core. The heat dissipation area of the roll core structure and the specific energy of the battery are obviously increased, and the heat management efficiency and the battery performance are obviously improved. According to the preparation process, lamination, negative plate micro-processing and thermal compounding are combined, compounding is realized by a one-step method, the product consistency is high, the investment is low, and the operation is simple. The preparation system is scientific in design, compact in layout and easy to implement.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and in particular to a laminated lithium battery core structure and a preparation process and system thereof. Background Art

[0002] Compared with traditional wound lithium batteries, stacked lithium batteries have higher energy density, longer cycle life, better safety, higher flexibility and better heat dissipation performance, and therefore have broad application prospects and development potential.

[0003] However, there are also some challenges for stacked lithium batteries, such as further optimization of heat dissipation performance. As we all know, due to the scale cluster characteristics of lithium-ion batteries used in energy storage systems, thermal runaway of a single battery will further spread rapidly throughout the battery box and even the entire energy storage system, forming a chain combustion and explosion reaction. In order to better prevent thermal runaway of lithium-ion batteries, temperature control of lithium batteries during use is very important.

[0004] In order to control the temperature of the battery from the inside, some existing wound lithium batteries are equipped with liquid cooling channels on the core rod to effectively suppress the temperature rise of the battery. However, this type of wound lithium battery has the following shortcomings: (1) From the perspective of energy density: the volume waste rate is high, and there is a certain amount of space waste at the four corners of the internal winding core and the external shell, which is not conducive to improving the energy density of the lithium battery; (2) From the perspective of winding efficiency: the winding process is complicated on the core rod with a liquid cooling channel, and the winding efficiency is lower than the conventional winding process. Moreover, the core needs to be shaped under high temperature and high pressure after winding, so the overall production efficiency is not high; (3) From the perspective of yield rate: during hot pressing shaping, due to the liquid cooling channel on the core rod, the mechanical properties are relatively worse than those of ordinary core rods, so it is easy to cause mechanical damage, which eventually leads to fatigue failure of the core rod, contact between the coolant and the electrolyte, and safety failure. Moreover, after hot pressing shaping, the gap between the pole pieces at the rounded corners of the core will change, affecting the battery performance, so the yield rate is relatively low; (4) From the perspective of heat dissipation uniformity: the unit contact area at the arc of the core rod is small, which leads to poor heat conduction effect and poor heat dissipation uniformity.

[0005] In the prior art, the temperature control of laminated lithium batteries is concentrated through external cooling methods, such as adding cooling plates at the bottom or side of the lithium battery, which indirectly reduces the temperature of the lithium battery during use and improves high-temperature performance. However, the external cooling method has the following disadvantages: low space utilization, poor cooling effect, large temperature difference between inside and outside, poor size compatibility, high production cost and maintenance cost. Moreover, when laminating, the negative electrode plate and the diaphragm are usually first thermally composited, then cut into sheets, and then laminated with the positive electrode plate for the second time. This two-step thermal composite method not only has a greater risk of misalignment when laminating, but also has a cumbersome operation process, resulting in low lamination efficiency.

[0006] To this end, this application is filed. Summary of the invention

[0007] In view of the above-mentioned shortcomings of the prior art, the present invention provides a laminated lithium battery core structure and a preparation process and system thereof.

[0008] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0009] First, the present invention proposes a laminated lithium battery core structure, including: a left core, a liquid cooling plate, a right core and an insulating film;

[0010] The left part of the winding core is a laminated structure formed by folding the left separator in a "Z" shape and inserting the left negative electrode sheets and the left positive electrode sheets alternately into the left separator layer by layer, and multiple groups of left negative electrode sheets and multiple groups of left positive electrode sheets are all wrapped by the left separator;

[0011] The liquid cooling plate comprises a liquid cooling plate body, a plurality of internal flow channels are arranged in the liquid cooling plate body, and a plurality of cooling liquid collecting ports communicating with the internal flow channels are arranged at the top and bottom ends of the liquid cooling plate body;

[0012] The right part of the winding core is a laminated structure formed by folding the right separator in a "Z" shape and inserting the right negative electrode sheet and the right positive electrode sheet into the right separator alternately layer by layer, and multiple groups of right negative electrode sheets and multiple groups of right positive electrode sheets are all wrapped by the right separator;

[0013] The left diaphragm and the right diaphragm are the same continuous diaphragm, the liquid cooling plate is located between the left and right parts of the core and is separated from the left and right parts of the core by the continuous diaphragm, and the insulating film is wrapped around the stacked structure formed by the left part of the core, the liquid cooling plate and the right part of the core.

[0014] Preferably, the left negative electrode sheet and the right negative electrode sheet adjacent to the liquid cooling plate body and the outermost left negative electrode sheet and the right negative electrode sheet are negative electrode sheets coated with negative electrode slurry on one side and a plurality of hemispherical indentations are distributed on the side coated with the negative electrode slurry; the hemispherical indentations are distributed on both surfaces of the remaining left negative electrode sheet and the remaining right negative electrode sheet.

[0015] Second, the present invention proposes a preparation process of a laminated lithium battery roll core structure, comprising the following steps:

[0016] S1. Place the cut negative electrode sheets and positive electrode sheets neatly at designated locations and prepare the separator rolls;

[0017] S2. After the diaphragm is continuously output from the diaphragm roll without being cut off and both sides of the diaphragm are heated, at least one layer of the diaphragm is first stacked, and then a layer of the negative electrode sheet is placed on the upper surface of the diaphragm, and a plurality of indentations are provided on the lower surface of the negative electrode sheet. Then, the upper surface of the negative electrode sheet is heated and pressurized so that the negative electrode sheet is composited with the diaphragm below it and a plurality of indentations are also formed on the upper surface of the negative electrode sheet. Then, a layer of the diaphragm and a layer of the positive electrode sheet are successively stacked on the upper surface of the negative electrode sheet, and the upper surface of the positive electrode sheet is heated so that the positive electrode sheet is composited with the diaphragm below it. Then, the same stacking operation as above is adopted to stack a layer of the diaphragm, a layer of the negative electrode sheet, a layer of the diaphragm, and a layer of the positive electrode sheet in the order of stacking to a predetermined thickness to form the left part of the winding core, and a liquid cooling plate is placed on the left part of the winding core. The stacking operation is repeated to form the right part of the winding core.

[0018] S3. An insulating film is wrapped around the laminated structure formed on the left side of the winding core, the liquid cooling plate, and the right side of the winding core.

[0019] Further, in step S1, the negative electrode sheet includes a single-sided negative electrode sheet coated with a negative electrode active material on one side and a double-sided negative electrode sheet coated with a negative electrode active material on both sides, and the single-sided negative electrode sheet is placed separately from the double-sided negative electrode sheet; in step S2, the negative electrode sheets adjacent to the liquid cooling plate body and the outermost layer are both single-sided negative electrode sheets, the single-sided negative electrode sheet adjacent to the liquid cooling plate body has a side coated with the negative electrode active material facing away from the liquid cooling plate body, and the single-sided negative electrode sheet on the outermost layer has a side coated with the negative electrode active material facing away from the outermost layer of the diaphragm.

[0020] Specifically, in step S2, 1 to 4 layers of the separator are stacked in a "Z" shape at first, and then a layer of the negative electrode sheet is placed on the upper surface of the separator.

[0021] Third, the present invention proposes a preparation system for a laminated lithium battery roll core structure, including: a negative electrode sheet collection bin, a negative electrode sheet microprocessor, a negative electrode sheet positioning platform, a diaphragm conveying mechanism, a thermal composite lamination platform, a positive electrode sheet suction cup, a positive electrode sheet positioning platform, a positive electrode sheet collection bin and a liquid cooling plate collection bin;

[0022] The negative electrode sheet microprocessing device comprises: a feeding suction cup, a negative electrode sheet microprocessing platform and a three-way moving mechanism for the feeding suction cup; a negative pressure cavity I is arranged inside the feeding suction cup, and a plurality of through holes I connected to the negative pressure cavity I are provided on the bottom surface of the feeding suction cup; the negative electrode sheet microprocessing platform comprises a negative electrode sheet microprocessing platform body, a negative pressure cavity II is arranged inside the negative electrode sheet microprocessing platform body, a plurality of protruding units are distributed in an array on the upper surface of the negative electrode sheet microprocessing platform body, a through hole II connected to the negative pressure cavity II is provided on the protruding unit, a negative pressure pipeline connected to the negative pressure cavity II is also provided on the negative electrode sheet microprocessing platform body, and a negative pressure interface II is provided on the negative pressure pipeline; the bottom surface of the feeding suction cup is arranged opposite to the upper surface of the negative electrode sheet microprocessing platform body, the feeding suction cup is connected to the three-way moving mechanism of the feeding suction cup, and the feeding suction cup presses the upper surface of the negative electrode sheet microprocessing platform body under the action of the three-way moving mechanism of the feeding suction cup;

[0023] The diaphragm conveying mechanism is used to heat the two surfaces of the diaphragm and fold them into a "Z" shape on the hot composite lamination table;

[0024] The hot composite lamination table includes a movable hot pressing sucker, a movable operating table and a plate pressing mechanism. The structure of the hot pressing sucker is symmetrical with that of the negative plate micro-processing table and has a heating function. The operating surface of the operating table is provided with a number of negative pressure adsorption holes.

[0025] The negative electrode sheets in the negative electrode sheet collection bin are first micro-processed by the negative electrode sheet micro-processing device to form dents on their surfaces, and then accurately positioned by the negative electrode sheet positioning table and transported to the hot composite lamination table. The positive electrode sheets in the positive electrode sheet collection bin are first sucked by the positive electrode sheet suction cup and transported to the positive electrode sheet positioning table, and then accurately positioned by the positive electrode sheet positioning table and transported to the hot composite lamination table. The liquid cooling plate is transported from the liquid cooling plate collection bin to the hot composite lamination table, and the diaphragm, negative electrode sheet, positive electrode sheet, and liquid cooling plate are composited on the hot composite lamination table to form a winding core structure.

[0026] Preferably, the negative electrode sheet collection bin includes: a double-sided negative electrode sheet collection bin, a first single-sided negative electrode sheet collection bin and a second single-sided negative electrode sheet collection bin. The double-sided negative electrode sheet collection bin is used to place negative electrode sheets coated with negative electrode slurry on both sides, the first single-sided negative electrode sheet collection bin is used to place negative electrode sheets with negative electrode slurry coated on the upper surface, and the second single-sided negative electrode sheet collection bin is used to place negative electrode sheets with negative electrode slurry coated on the lower surface.

[0027] Preferably, a pressure detector is provided at the bottom of the loading suction cup and the hot pressing suction cup respectively.

[0028] Preferably, a pair of heating rollers are provided at the output end of the diaphragm conveying mechanism, and heating resistance wires are respectively provided in the heating rollers and the hot pressure suction cups, and the heating resistance wires are also respectively connected to temperature detectors.

[0029] Preferably, the protruding unit is a hemispherical protrusion, the through hole II is vertically arranged and located in the middle of the hemispherical protrusion, and the negative pressure pipeline is vertically arranged at the lower part of the micro-processing station body and communicated with the middle of the negative pressure chamber II.

[0030] Compared with the prior art, the present invention performs microprocessing on one side of the negative electrode sheet and then composites the positive electrode sheet, the separator and the negative electrode sheet by a one-step thermal composite method. During the composite process, the other side of the negative electrode sheet is microprocessed, and then the sheets are stacked and a liquid cooling plate is designed in the middle of the battery cell. The present invention has at least the following beneficial effects:

[0031] (1) The setting of the liquid cooling plate increases the heat dissipation area exponentially, solving the problem of uneven heat dissipation in the prior art, and significantly improving the thermal management efficiency and comprehensive performance of the battery;

[0032] (2) The positive and negative electrode sheets and the separator are laminated in a one-step hot composite method. This new hot composite method not only reduces the operating difficulty of the core hot pressing shaping process in the prior art, has a high yield rate, but also avoids the safety failure caused by mechanical damage to the core rod during the hot pressing process and the adverse effects on battery performance. It also saves the processes of roller hot composite and hot composite after cutting, reduces equipment investment, and improves production efficiency.

[0033] (3) The volume utilization rate of the core structure obtained by the stacking method is high. Under the combined effect of the new negative electrode sheet surface scoring technology and the negative electrode design of the outermost layer of the core and the negative electrode adjacent to the liquid cooling plate being coated with negative electrode slurry on one side, the resulting product has high energy density and good size compatibility;

[0034] (4) The preparation process proposed by the present invention not only has high production efficiency and low production cost, but also improves the consistency of the product. The preparation system proposed by the present invention is scientifically designed, compactly laid out, and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 A cross-sectional view of the laminated lithium battery core structure proposed by the present invention along the horizontal direction;

[0037] Figure 2 for Figure 1 A schematic diagram of the enlarged structure at A in the middle;

[0038] Figure 3 for Figure 1 A schematic diagram of the enlarged structure at B in the middle;

[0039] Figure 4 A schematic diagram of the three-dimensional structure of the laminated lithium battery roll core structure proposed by the present invention;

[0040] Figure 5 It is a structural schematic diagram of the negative electrode sheet microprocessing device in the laminated lithium battery roll core structure preparation system proposed by the present invention;

[0041] Figure 6 for Figure 5 Schematic diagram of the enlarged structure at C in the middle;

[0042] Figure 7 For the Sutra Figure 5 A schematic diagram of the structure of the negative electrode sheet after being processed by the device shown;

[0043] Figure 8 It is a structural schematic diagram of the diaphragm conveying mechanism and the thermal composite lamination table in the laminated lithium battery core structure preparation system proposed in the present invention;

[0044] Fig. 9 For the negative electrode Figure 8 Schematic diagram of the structure after the hot pressing suction cup is processed;

[0045] Fig.10 A schematic diagram of the structure of the laminated lithium battery core structure preparation system proposed by the present invention;

[0046] Fig.11 for Fig.10 Schematic diagram of the enlarged structure at M in the middle;

[0047] Fig.12 for Fig.10 Schematic diagram of the movement of the operating table when the medium-heat composite lamination table is laminating;

[0048] Fig.13 for Fig.10 Schematic diagram of the enlarged structure at Q in the middle.

[0049] In the figure: 1. Left part of winding core; 11. Left diaphragm; 12. Left negative electrode sheet; 13. Left positive electrode sheet; 2. Liquid cooling plate; 21. Liquid cooling plate body; 22. Cooling liquid collection port; 23. Internal flow channel; 3. Right part of winding core; 31. Right diaphragm; 32. Right negative electrode sheet; 33. Right positive electrode sheet; 4. Insulating film; 5. Loading suction cup; 51. Loading suction cup body I; 511. Negative pressure interface I; 52. Loading suction cup body II; 521. Negative pressure cavity I; 522. Through hole I; 53. Three-way moving mechanism of loading suction cup; 6. Negative electrode sheet micro-processing station; 61. Negative electrode sheet micro-processing station body; 62. Negative pressure cavity II; 63. Negative pressure interface II; 64. Through hole II; 65. Protruding unit; 7. Negative electrode sheet; 71. Indentation; 8. Diaphragm conveying mechanism; 81. Unwinding device; 8 2. Tension adjustment device; 83. Correction device; 84. Heating roller; 9. Thermal composite stacking station; 91. Hot pressing suction cup; 92. Operating table; 93. Operating table moving motor; 94. Hot pressing suction cup three-way moving mechanism; 95. Press block; D. Positive electrode sheet collection bin; E. Mounting bracket; F. Vacuum pipeline; G. Negative electrode sheet positioning station; G1. First negative electrode sheet positioning station servo motor; G2. Second negative electrode positioning station servo motor; H. Liquid cooling plate collection bin; I. Positive electrode sheet positioning station; I1. First positive electrode sheet positioning station servo motor; I2. Second positive electrode positioning station servo motor; J. Positive electrode sheet suction cup; J1. Positive electrode sheet suction cup three-way moving mechanism; K. Mounting base plate; L. Vacuum pump; N. Double-sided negative electrode sheet collection bin; O. First single-sided negative electrode sheet collection bin; P. Second single-sided negative electrode sheet collection bin. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0051] The structures not described in detail in the following embodiments are all prior art, such as the three-way moving mechanisms, the power drive mechanisms such as the servo motors mentioned, and the directional words such as "upper surface", "lower surface", "bottom surface", "left side", "right side" etc. used to clearly describe the component structure are only used to describe their relative positional relationship and are not used to limit the scope of protection of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "several" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0052] like Figure 1-Figure 4 As shown in common: The present invention provides a laminated lithium battery core structure, comprising: a core left portion 1, a liquid cooling plate 2, a core right portion 3 and an insulating film 4;

[0053] The left part 1 of the winding core is a laminated structure formed by folding the left separator 11 in a "Z" shape and inserting the left negative electrode sheet 12 and the left positive electrode sheet 13 into the left separator 11 alternately layer by layer, and multiple groups of left negative electrode sheets 12 and multiple groups of left positive electrode sheets 13 are all wrapped by the left separator 11;

[0054] The liquid cooling plate 2 includes a liquid cooling plate body 21, a plurality of internal flow channels 23 are arranged in the liquid cooling plate body 21, and a plurality of cooling liquid collecting ports 22 communicating with the internal flow channels 23 are arranged at the top and bottom ends of the liquid cooling plate body 21;

[0055] The right part 3 of the winding core is a laminated structure formed by folding the right separator 31 in a "Z" shape and inserting the right negative electrode sheet 32 ​​and the right positive electrode sheet 33 into the right separator 31 alternately layer by layer, and multiple groups of right negative electrode sheets 32 and multiple groups of right positive electrode sheets 33 are all wrapped by the right separator 31;

[0056] The left diaphragm 11 and the right diaphragm 31 are the same continuous diaphragm. The liquid cooling plate 2 is located between the left part 1 of the core and the right part 3 of the core and is separated from the left part 1 of the core and the right part 3 of the core by the continuous diaphragm. The insulating film 4 is wrapped around the stacked structure formed by the left part 1 of the core, the liquid cooling plate 2 and the right part 3 of the core.

[0057] The present invention forms a roll core structure in a stacked manner and creatively designs the cooling structure traditionally arranged at the bottom or side of the lithium battery in the middle of the battery roll core, which not only doubles the heat dissipation area, significantly improves the thermal management efficiency, and significantly reduces energy consumption, but also increases the energy density of the battery. The resulting stacked lithium battery roll core structure has low system integration and maintenance costs, good size compatibility, and strong applicability to extremely hot and extremely cold environments.

[0058] As a preferred technical solution, in another embodiment of the present invention, the left negative electrode sheet 12 and the right negative electrode sheet 32 ​​adjacent to the liquid cooling plate body 21 and the outermost left negative electrode sheet 12 and the right negative electrode sheet 32 ​​are all negative electrode sheets coated with negative electrode slurry on one side and a plurality of hemispherical indentations are distributed on the side coated with the negative electrode slurry; both surfaces of the remaining left negative electrode sheet 12 and the remaining right negative electrode sheet 32 ​​are distributed with hemispherical indentations.

[0059] In this embodiment, the surface of the negative electrode sheet is provided with indentations, which, on the one hand, can increase the surface area of ​​the electrode sheet without significantly increasing the total volume of the electrode sheet, which helps to improve the liquid retention capacity of the negative electrode sheet and promote heat dissipation; on the other hand, it helps to shorten the transmission path of ions in the electrolyte, reduce the transmission resistance of ions, and improve the ion transmission efficiency of the battery; and it can reduce the stress concentration and deformation caused by volume changes during the charge and discharge process, and enhance the structural stability.

[0060] In this embodiment, the left negative electrode sheet 12 and the right negative electrode sheet 32 ​​adjacent to the liquid cooling plate body 21 and the outermost left negative electrode sheet 12 and the right negative electrode sheet 32 ​​are all negative electrode sheets coated with negative electrode slurry on one side, mainly for the following reasons: on the one hand, the single-sided coating can reduce the weight of the negative electrode sheet, and on the other hand, it helps to strengthen the contact between the outermost left negative electrode sheet 12 and the right negative electrode sheet 32 ​​and the insulating film 4, ensure the binding effect of the insulating film 4, and prevent the occurrence of curling, warping and other quality problems. More importantly, such a design helps to further improve the volume utilization of the core structure and improve the specific energy of the battery.

[0061] The preparation process of the laminated lithium battery roll core structure in the above embodiment includes the following steps:

[0062] S1. Place the cut negative electrode sheets and positive electrode sheets neatly at designated locations and prepare the separator rolls;

[0063] S2. After the diaphragm is continuously output from the diaphragm roll without being cut off and both sides of the diaphragm are heated, at least one layer of the diaphragm is first stacked, and then a layer of the negative electrode sheet is placed on the upper surface of the diaphragm, and a plurality of indentations are provided on the lower surface of the negative electrode sheet. Then, the upper surface of the negative electrode sheet is heated and pressurized so that the negative electrode sheet is composited with the diaphragm below it and a plurality of indentations are also formed on the upper surface of the negative electrode sheet. Then, a layer of the diaphragm and a layer of the positive electrode sheet are successively stacked on the upper surface of the negative electrode sheet, and the upper surface of the positive electrode sheet is heated so that the positive electrode sheet is composited with the diaphragm below it. Then, the same stacking operation as above is adopted to stack a layer of the diaphragm, a layer of the negative electrode sheet, a layer of the diaphragm, and a layer of the positive electrode sheet in the order of stacking to a predetermined thickness to form the left part 1 of the winding core, and the liquid cooling plate 2 is placed on the left part 1 of the winding core. The stacking operation is repeated to form the right part 3 of the winding core.

[0064] S3. Wrap the insulating film 4 around the laminated structure formed by the left part 1 of the winding core, the liquid cooling plate 2, and the right part 3 of the winding core.

[0065] As a preferred technical solution, in another embodiment of the present invention, in step S1, the negative electrode sheet includes a single-sided negative electrode sheet coated with a negative electrode active material on one side and a double-sided negative electrode sheet coated with a negative electrode active material on both sides, and the single-sided negative electrode sheet is placed separately from the double-sided negative electrode sheet; in step S2, the negative electrode sheet adjacent to the liquid cooling plate body 21 and the outermost layer are both single-sided negative electrode sheets, and the single-sided negative electrode sheet adjacent to the liquid cooling plate body 21 has a side coated with the negative electrode active material facing away from the liquid cooling plate body 21, and the single-sided negative electrode sheet on the outermost layer has a side coated with the negative electrode active material facing away from the outermost layer of the diaphragm.

[0066] As a preferred technical solution, in another embodiment of the present invention, in step S2, 1-4 layers of the separator are first stacked in a "Z" shape, and then a layer of the negative electrode sheet is placed on the upper surface of the separator.

[0067] like Figure 5-Figure 13 As shown in common: The present invention also proposes a preparation system for a laminated lithium battery roll core structure, including: a double-sided negative electrode sheet collection bin N, a first single-sided negative electrode sheet collection bin O, a second single-sided negative electrode sheet collection bin P, a negative electrode sheet microprocessor, a negative electrode sheet positioning platform G, a diaphragm conveying mechanism 8, a thermal composite lamination platform 9, a positive electrode sheet suction cup J, a positive electrode sheet positioning platform I, a positive electrode sheet collection bin D and a liquid cooling plate collection bin H; the double-sided negative electrode sheet collection bin N is used to place negative electrode sheets coated with negative electrode slurry on both sides;

[0068] The first single-sided negative electrode sheet collecting bin O is used to place the negative electrode sheet with negative electrode slurry coated on the upper surface;

[0069] The second single-sided negative electrode sheet collecting bin P is used to place the negative electrode sheet coated with negative electrode slurry on the lower surface; the negative electrode sheet microprocessing device includes: a feeding suction cup 5, a negative electrode sheet microprocessing platform 6 and a three-way moving mechanism 53 for the feeding suction cup; a negative pressure cavity I 521 is arranged inside the feeding suction cup 5, and a plurality of through holes I 522 communicating with the negative pressure cavity I 521 are opened on the bottom surface of the feeding suction cup 5; the negative electrode sheet microprocessing platform 6 includes a negative electrode sheet microprocessing platform body 61, a negative pressure cavity II 62 is arranged inside the negative electrode sheet microprocessing platform body 6 1 has a plurality of protruding units 65 arranged in an array on its upper surface, and a through hole II 64 communicating with the negative pressure chamber II 62 is provided on the protruding unit 65, and a negative pressure pipeline communicating with the negative pressure chamber II 62 is also provided on the negative electrode sheet micro-processing platform body 61, and a negative pressure interface II 63 is provided on the negative pressure pipeline; the bottom surface of the loading suction cup 5 is arranged opposite to the upper surface of the negative electrode sheet micro-processing platform body 61, and the loading suction cup 5 is connected to the loading suction cup three-way moving mechanism 53, and the loading suction cup 5 presses the upper surface of the negative electrode sheet micro-processing platform body 61 under the action of the loading suction cup three-way moving mechanism 53;

[0070] The negative electrode sheet positioning platform G is used to realize the precise positioning of the negative electrode sheet, specifically, it comprises: a negative electrode sheet positioning platform body, a first negative electrode sheet positioning platform servo motor G1 and a second negative electrode positioning platform servo motor G2, the first negative electrode sheet positioning platform servo motor G1 and the second negative electrode positioning platform servo motor G2 work together to realize the left and right and front and back movement of the negative electrode sheet positioning platform body, thereby ensuring the precise positioning of the negative electrode sheet;

[0071] The membrane conveying mechanism 8 is used to heat the two surfaces of the membrane and then convey them to the thermal composite lamination stage 9 and cooperate with the thermal composite lamination stage 9 to fold the membrane in a "Z" shape;

[0072] The thermal composite lamination station 9 is used, on the one hand, to further process the negative electrode sheet processed by the negative electrode sheet microprocessing station 6 to form a hemispherical indentation on the other side thereof, and on the other hand, to thermally composite the positive and negative electrode sheets with the diaphragm, and the indentation operation and the thermal composite are completed in one step. It includes a movable hot-pressing suction cup 91, a movable operating table 92 and an electrode sheet pressing mechanism. The structure of the hot-pressing suction cup 91 is symmetrical with that of the negative electrode sheet microprocessing station 6 and has a heating function. The operating surface of the operating table 92 is provided with a number of negative pressure adsorption holes; the positive electrode sheet suction cup J is used to absorb the positive electrode sheet and place it on the positive electrode sheet positioning station I. It is arranged above the positive electrode sheet positioning station I, and is connected to a positive electrode sheet suction cup three-way moving mechanism J1;

[0073] The positive electrode sheet positioning platform I is used to realize the precise positioning of the positive electrode sheet, specifically, it comprises: a positive electrode sheet positioning platform body, a first positive electrode sheet positioning platform servo motor I1 and a second positive electrode positioning platform servo motor I2, the first positive electrode sheet positioning platform servo motor I1 and the second positive electrode positioning platform servo motor I2 work together to realize the left and right and front and back movement of the positive electrode sheet positioning platform body, thereby ensuring the precise positioning of the positive electrode sheet;

[0074] The positive electrode sheet collecting bin D is used to place the positive electrode sheets;

[0075] The liquid cooling plate collecting bin H is used to place the liquid cooling plate 2 .

[0076] In this preparation system, for the convenience of operation, the positive electrode sheet and the liquid cooling plate related devices are arranged on one side of the hot composite lamination platform 9, and the negative electrode sheet related devices are arranged on the other side opposite to the hot composite lamination platform 9. Specifically, the left side of the hot composite lamination platform 9 is arranged in order from far to near: the double-sided negative electrode sheet collection bin N, the first single-sided negative electrode sheet collection bin O, the second single-sided negative electrode sheet collection bin P, the negative electrode sheet micro-processing station 6, the negative electrode sheet positioning station G, and the loading suction cup 5 is arranged above the negative electrode sheet micro-processing station 6; the right side of the hot composite lamination platform 9 is arranged in order from far to near: the liquid cooling plate collection bin H, the positive electrode sheet collection bin D, the positive electrode sheet positioning station I, and the positive electrode sheet suction cup J is arranged above the positive electrode sheet positioning station I; the specific installation position of the diaphragm conveying mechanism 8 depends on the specific situation and is not required.

[0077] Furthermore, in this embodiment, a vacuum pump L is also included, and the vacuum pump L provides negative pressure support to the upper material suction cup 5, the negative electrode sheet micro-processing table 6, the thermal composite stacking table 9, and the positive electrode sheet suction cup J through the vacuum pipe F.

[0078] Furthermore, in the present embodiment, the loading suction cup 5 specifically includes a loading suction cup body Ⅰ51 and a loading suction cup body Ⅱ52 which are integrated in design and in an inverted "T" shape, the negative pressure chamber Ⅰ521 is located in the loading suction cup body Ⅱ52, the through hole Ⅰ522 is distributed on the bottom surface of the loading suction cup body Ⅱ52, the loading suction cup body Ⅰ51 is connected to the pressurizing device and a negative pressure pipeline is arranged inside, and a negative pressure interface Ⅰ511 for connecting the vacuum pipe F is arranged on the negative pressure pipeline.

[0079] Specifically, the loading suction cup body I51 is located directly above the loading suction cup body II52, and the pressure-applying device is preferably connected to the top of the loading suction cup body I51, and the pressure applied by the pressure-applying device is evenly distributed to the bottom surface of the loading suction cup body II52, and acts evenly on the surface to be processed of the pole piece 7 through the bottom surface of the loading suction cup body II52, and finally forms a relatively uniform indentation 71 on the surface to be processed (such as Figure 7 If the pressure applied by the pressurizing device cannot be evenly applied to the surface to be processed, the dents 71 formed will be of different sizes, and ultimately a pole piece 7 of good quality cannot be obtained.

[0080] Furthermore, in this embodiment, the protruding unit 65 is a hemispherical protrusion, the through hole II 64 is vertically arranged and located in the middle of the hemispherical protrusion, and the negative pressure pipeline is vertically arranged at the lower part of the micro-processing station body 61 and communicates with the middle of the negative pressure chamber II 62 .

[0081] The through hole II 64 is vertically arranged and located in the middle of the protruding unit 65, which can collect the dust generated during micro-processing in a timely and effective manner to prevent the dust from contaminating the electrode and causing a short circuit or large self-discharge in the battery; the negative pressure pipeline is vertically arranged at the lower part of the micro-processing station body 61 and is connected to the middle part of the negative pressure chamber II 62, that is, the negative pressure pipeline can provide a relatively uniform negative pressure adsorption force for the through hole II 64, so as to collect the dust generated by the micro-processing with the highest efficiency and quality possible.

[0082] Further, in this embodiment, the diaphragm conveying mechanism 8 includes: an unwinding device 81, a tension adjusting device 82, a deflection correcting device 83, and a heating roller 84. The diaphragm is wound on the unwinding device 81, and is conveyed to the thermal composite lamination station 9 after the tension is adjusted by the tension adjusting device 82, the deflection correcting device 83 is used for deflection correction, and the heating roller 84 is used for double-sided heating. The heating roller 84 and the hot pressing suction cup 91 are respectively provided with heating resistance wires, and the heating resistance wires are also respectively connected to a temperature detector. Taking the heating roller 84 as an example, the heating temperature is controlled to be 80-120°C through the temperature detector connected thereto, so as to ensure that both sides of the diaphragm are heated, so as to facilitate the thermal composite with the positive and negative electrode sheets on the operating table 92.

[0083] Furthermore, in this embodiment, the hot-pressing suction cup 91 is provided with a three-way moving mechanism 94, through which the hot-pressing suction cup 91 can be flexibly moved in three axes; the operating table 92 is provided with an operating table moving motor 93, through which the operating table moving motor 93 acts on the operating table 92 to move in three axes. Fig.12 The reciprocating motion between position one and position two shown realizes the Z-shaped lamination of the diaphragm.

[0084] Further, in this embodiment, the pole piece pressing mechanism is specifically a number of four pressing blocks 95, and the specific structure of the pressing blocks 95 is as follows: Fig.13 As shown: the four pressing blocks 95 are used to press the four corners of the pole piece respectively. The specific structure includes: a pressing block body, a tension spring, a servo motor, a bracket, etc. One end of the pressing block body is rotatably connected to the bracket. The tension spring is arranged at the bottom of the pressing block body and when the tension spring is in a natural state, the pressing block body maintains a horizontal state and presses the pole piece. When the cylinder of the servo motor moves downward, it acts on the pressing block body to make the pressing block body gradually tilt from a horizontal state to a vertical state, and a decompression operation is formed at this time. When the cylinder of the servo motor is retracted, the pressing block body automatically returns to a horizontal state under the action of the tension spring, and then presses the pole piece.

[0085] Furthermore, in this embodiment, it also includes an installation base plate K and an installation bracket E, a double-sided negative electrode sheet collection bin N, a first single-sided negative electrode sheet collection bin O, a second single-sided negative electrode sheet collection bin P, a negative electrode sheet micro-processing station 6, a negative electrode sheet positioning station G, an operating table 92, a positive electrode sheet positioning station I, a positive electrode sheet collection bin D, and a liquid cooling plate collection bin H are arranged on the installation base plate K; a loading suction cup 5, a hot pressing suction cup 91, and a positive electrode sheet suction cup J are respectively arranged on the installation bracket E through a loading suction cup three-way moving mechanism 53, a hot pressing suction cup three-way moving mechanism 94, and a positive electrode sheet suction cup three-way moving mechanism J1.

[0086] When the stacked lithium battery roll core structure is prepared using the above-mentioned preparation system according to the preparation process shown in the present invention, the specific operation steps are as follows:

[0087] (1) stacking a plurality of membrane layers on the operating table 92 through the membrane conveying mechanism 8, the number of membrane layers is preferably 1-4 layers, and the operating table 92 is located at the first position after the membrane layers are stacked;

[0088] (2) The loading suction cup 5 sucks the single-sided negative electrode sheet in the first single-sided negative electrode sheet collecting bin B and places it on the negative electrode sheet positioning table G;

[0089] (3) The negative electrode sheet positioning station G accurately positions the single-sided negative electrode sheet and then sucks it up through the hot-pressing suction cup 91 and transports it to the operating station 92. The hot-pressing suction cup 91 applies downward pressure to composite the single-sided negative electrode sheet and the separator layer together;

[0090] (4) moving the operating table 92 from position one to position two;

[0091] (5) The positive electrode suction cup J sucks the positive electrode sheet and places it on the positive electrode sheet positioning platform I. After being accurately positioned by the positive electrode sheet positioning platform I, it is sucked by the hot pressure suction cup 91 and transported to the operating platform 92. The hot pressure suction cup 91 applies downward pressure to composite the positive electrode sheet and the separator together;

[0092] (6) Move the operating table 92 from position 2 to position 1;

[0093] (7) The loading suction cup 5 sucks the double-sided negative electrode sheet in the double-sided negative electrode sheet collecting bin N and places it on the negative electrode sheet micro-processing table 6. The loading suction cup three-way moving mechanism 53 moves the loading suction cup 5 downward and applies a certain pressure to the negative electrode sheet micro-processing table 6, pressing a hemispherical indentation on the lower surface of the double-sided negative electrode sheet;

[0094] (8) The loading suction cup 5 sucks the processed double-sided negative electrode sheet and transports it to the negative electrode sheet positioning station G;

[0095] (9) The negative electrode sheet positioning station G accurately positions the processed double-sided negative electrode sheet, which is then sucked up by the hot-pressing suction cup 91 and transported to the operating station 92. The hot-pressing suction cup 91 applies downward pressure to combine the negative electrode sheet with the separator layer. During this process, a hemispherical indentation is also formed on the upper surface of the negative electrode sheet.

[0096] (10) The operating table 92 moves from position 1 to position 2;

[0097] (11) Repeat the above steps (4) to (9) until the number of positive and negative electrode sheets in the stack reaches the target number;

[0098] (12) Move the operating table 92 from position 2 to position 1;

[0099] (13) The loading suction cup 5 sucks the second single-sided negative electrode sheet in the second single-sided negative electrode sheet collecting bin P and places it on the negative electrode sheet micro-processing table 6. The loading suction cup three-way moving mechanism 53 moves the loading suction cup 5 downward and applies a certain pressure to the negative electrode sheet micro-processing table 6, pressing a hemispherical indentation on the lower surface of the second single-sided negative electrode sheet;

[0100] (14) The operating table 92 moves from position 1 to position 2;

[0101] (15) The operating table 92 is kept at position 2, and the hot pressure suction cup 91 sucks the liquid cooling plate 2 in the liquid cooling plate collection bin H and delivers it to the operating table 92. The hot pressure suction cup 91 applies downward pressure to compound the liquid cooling plate 2 and the diaphragm together;

[0102] (16) Repeat steps (1) to (13) again to form a winding core above the cooling plate 2;

[0103] (17) The rolled laminated lithium battery core structure is transferred out of the hot composite lamination table, and the diaphragm is adsorbed on the empty operating table 92, and the diaphragm is cut off. At this time, the operating table 92 stays in one position.

[0104] In this embodiment, the pressure of the hot pressing chuck 91 during hot pressing is preferably 300-5000 kgf, and the loading chuck 5 preferably also forms 300-5000 kgf on the negative electrode micro-processing station body 61 under the action of the loading chuck three-way moving mechanism 53. Preferably, the loading chuck 5 and the hot pressing chuck 91 are each provided with a pressure sensor to realize automatic closed-loop control of the pressure.

[0105] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. Those skilled in the art may change, modify, replace and deform the above embodiments within the scope of the present invention. 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 without contradiction.

Claims

1. A laminated lithium battery core structure, characterized in that: include: The left part of the winding core (1), the liquid cooling plate (2), the right part of the winding core (3) and the insulating film (4); The left part of the winding core (1) is a laminated structure formed by folding the left separator (11) in a "Z" shape and inserting the left negative electrode sheets (12) and the left positive electrode sheets (13) alternately into the left separator (11) layer by layer, and multiple groups of left negative electrode sheets (12) and multiple groups of left positive electrode sheets (13) are all wrapped by the left separator (11); The liquid cooling plate (2) comprises a liquid cooling plate body (21), a plurality of internal flow channels (23) are arranged in the liquid cooling plate body (21), and a plurality of cooling liquid collecting ports (22) in communication with the internal flow channels (23) are arranged at the top and bottom ends of the liquid cooling plate body (21); The right part (3) of the winding core is a laminated structure formed by folding the right separator (31) in a "Z" shape and inserting the right negative electrode sheet (32) and the right positive electrode sheet (33) into the right separator (31) alternately layer by layer, and multiple groups of right negative electrode sheets (32) and multiple groups of right positive electrode sheets (33) are all wrapped by the right separator (31); The left diaphragm (11) and the right diaphragm (31) are the same continuous diaphragm, the liquid cooling plate (2) is located between the left part (1) and the right part (3) of the core and is separated from the left part (1) and the right part (3) of the core by the continuous diaphragm, and the insulating film (4) is wrapped around the laminated structure formed by the left part (1) of the core, the liquid cooling plate (2) and the right part (3) of the core.

2. The laminated lithium battery core structure according to claim 1, characterized in that: The left negative electrode sheet (12) and the right negative electrode sheet (32) adjacent to the liquid cooling plate body (21) and the outermost left negative electrode sheet (12) and the right negative electrode sheet (32) are all negative electrode sheets coated with negative electrode slurry on one side, and a plurality of hemispherical indentations are distributed on the side coated with the negative electrode slurry; the hemispherical indentations are distributed on both surfaces of the remaining left negative electrode sheet (12) and the remaining right negative electrode sheet (32).

3. A process for preparing the laminated lithium battery core structure according to claim 1, characterized in that: The steps are as follows: S1. Place the cut negative electrode sheets and positive electrode sheets neatly at designated locations and prepare the separator rolls; S2, after the diaphragm is continuously output from the diaphragm roll without being cut off and both sides of the diaphragm are heated, at least one layer of the diaphragm is first stacked, and then a layer of the negative electrode sheet is placed on the upper surface of the diaphragm, and a plurality of indentations are provided on the lower surface of the negative electrode sheet. Then, the upper surface of the negative electrode sheet is heated and pressurized so that the negative electrode sheet is composited with the diaphragm below and a plurality of indentations are also formed on the upper surface of the negative electrode sheet. Then, a layer of the diaphragm and a layer of the positive electrode sheet are sequentially stacked on the upper surface of the negative electrode sheet, and the upper surface of the positive electrode sheet is heated so that the positive electrode sheet is composited with the diaphragm below. Then, the same stacking operation as above is used to stack the layers in the order of a layer of the diaphragm, a layer of the negative electrode sheet, a layer of the diaphragm, and a layer of the positive electrode sheet to a predetermined thickness to form the left part (1) of the winding core, and the liquid cooling plate (2) is placed on the left part (1) of the winding core. The stacking operation is repeated to form the right part (3) of the winding core. S3. An insulating film (4) is wrapped around the laminated structure formed by the left part (1) of the winding core, the liquid cooling plate (2) and the right part (3) of the winding core.

4. The process for preparing the laminated lithium battery roll core structure according to claim 3, characterized in that: In step S1, the negative electrode sheet includes a single-sided negative electrode sheet coated with a negative electrode active material on one side and a double-sided negative electrode sheet coated with a negative electrode active material on both sides, and the single-sided negative electrode sheet is placed separately from the double-sided negative electrode sheet; In step S2, the negative electrode sheets adjacent to the liquid cooling plate body (21) and the outermost layer are both single-sided negative electrode sheets, the single-sided negative electrode sheet adjacent to the liquid cooling plate body (21) is arranged with the side coated with the negative electrode active material facing away from the liquid cooling plate body (21), and the single-sided negative electrode sheet of the outermost layer is arranged with the side coated with the negative electrode active material facing away from the outermost layer of the diaphragm.

5. The process for preparing the laminated lithium battery roll core structure according to claim 3, characterized in that: In step S2, 1-4 layers of the separator are first stacked in a "Z" shape, and then a layer of the negative electrode sheet is placed on the upper surface of the separator.

6. A system for preparing a laminated lithium battery core structure as claimed in claim 1, characterized in that: include: A negative electrode sheet collecting bin, a negative electrode sheet microprocessing device, a negative electrode sheet positioning platform (G), a diaphragm conveying mechanism (8), a thermal composite lamination platform (9), a positive electrode sheet suction cup (J), a positive electrode sheet positioning platform (I), a positive electrode sheet collecting bin (D) and a liquid cooling plate collecting bin (H); The negative electrode sheet microprocessing device comprises: a loading suction cup (5), a negative electrode sheet microprocessing platform (6) and a loading suction cup three-way moving mechanism (53); A negative pressure chamber I (521) is arranged inside the loading suction cup (5), and a plurality of through holes I (522) communicating with the negative pressure chamber I (521) are provided on the bottom surface of the loading suction cup (5); the negative electrode sheet micro-processing platform (6) comprises a negative electrode sheet micro-processing platform body (61), a negative pressure chamber II (62) is arranged inside the negative electrode sheet micro-processing platform body (61), and a plurality of protrusion units (65) are arranged in an array on the upper surface of the negative electrode sheet micro-processing platform body (61), and a plurality of through holes I (522) communicating with the negative pressure chamber II (62) are provided on the protrusion units (65). A through hole II (64) is connected to the negative electrode sheet micro-processing platform body (61); a negative pressure pipeline connected to the negative pressure chamber II (62) is also provided on the negative electrode sheet micro-processing platform body (61); a negative pressure interface II (63) is provided on the negative pressure pipeline; the bottom surface of the loading suction cup (5) is arranged opposite to the upper surface of the negative electrode sheet micro-processing platform body (61); the loading suction cup (5) is connected to the loading suction cup three-way moving mechanism (53); the loading suction cup (5) is pressed against the upper surface of the negative electrode sheet micro-processing platform body (61) under the action of the loading suction cup three-way moving mechanism (53); The diaphragm conveying mechanism (8) is used to heat the two surfaces of the diaphragm and then fold them in a "Z" shape on a hot composite lamination table (9); The thermal composite lamination platform (9) comprises a movable hot-pressing suction cup (91), a movable operating table (92) and a pole piece pressing mechanism; the structure of the hot-pressing suction cup (91) is symmetrical with that of the negative pole piece micro-processing table (6) and has a heating function; and a plurality of negative pressure adsorption holes are arranged on the operating surface of the operating table (92); The negative electrode sheets in the negative electrode sheet collection bin are first micro-processed by the negative electrode sheet micro-processing device to form indentations on their surfaces, and then accurately positioned by the negative electrode sheet positioning platform (G) and then transported to the thermal composite lamination platform (9). The positive electrode sheets in the positive electrode sheet collection bin (D) are first sucked by the positive electrode sheet suction cup (J) and transported to the positive electrode sheet positioning platform (I), and then accurately positioned by the positive electrode sheet positioning platform (I) and then transported to the thermal composite lamination platform (9). The liquid cooling plate is transported from the liquid cooling plate collection bin (H) to the thermal composite lamination platform (9), and the diaphragm, the negative electrode sheet, the positive electrode sheet, and the liquid cooling plate are composited on the thermal composite lamination platform (9) to form a winding core structure.

7. The system for preparing a laminated lithium battery roll core structure according to claim 6, characterized in that: The negative electrode sheet collection bin comprises: a double-sided negative electrode sheet collection bin (N), a first single-sided negative electrode sheet collection bin (O) and a second single-sided negative electrode sheet collection bin (P). The double-sided negative electrode sheet collection bin (N) is used to place negative electrode sheets coated with negative electrode slurry on both sides, the first single-sided negative electrode sheet collection bin (O) is used to place negative electrode sheets coated with negative electrode slurry on the upper surface, and the second single-sided negative electrode sheet collection bin (P) is used to place negative electrode sheets coated with negative electrode slurry on the lower surface.

8. The system for preparing a laminated lithium battery roll core structure according to claim 6, characterized in that: The bottoms of the loading suction cup (5) and the hot pressing suction cup (91) are respectively provided with pressure detectors.

9. The system for preparing a laminated lithium battery roll core structure according to claim 6, characterized in that: A pair of heating rollers (84) are arranged at the output end of the diaphragm conveying mechanism (8), and heating resistance wires are respectively arranged in the heating rollers (84) and the hot pressure suction cup (91), and the heating resistance wires are also respectively connected to temperature detectors.

10. The system for preparing a laminated lithium battery roll core structure according to claim 6, characterized in that: The protruding unit (65) is a hemispherical protrusion, the through hole II (64) is vertically arranged and located in the middle of the hemispherical protrusion, and the negative pressure pipeline is vertically arranged at the lower part of the micro-processing station body (61) and communicated with the middle part of the negative pressure chamber II (62).

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