Laminated cell and preparation equipment thereof

Abstract

The utility model discloses a laminated battery cell and preparation equipment thereof, the laminated battery cell is prepared by folding a battery cell structure, the battery cell structure comprises a first pole piece, a diaphragm and a second pole piece, the first pole piece is located on one side of the diaphragm, and the first pole piece is connected with the diaphragm through a normal-temperature normal-pressure conductive adhesive; and the second pole pieces are alternately arranged on the sides, away from the first pole pieces, of the diaphragms, and the second pole pieces are connected with the diaphragms through normal-temperature and normal-pressure conductive adhesives. The normal-temperature and normal-pressure conductive adhesive disclosed by the utility model has relatively good adhesion performance at normal temperature and normal pressure, and also has relatively good conductivity, so that the problem of poor battery performance caused by high-temperature and high-pressure thermal compounding of a pole piece and a diaphragm in the existing laminated cell processing process is solved, the condition of poor liquid absorption effect and interface of the battery is improved, and the service life of the battery is prolonged. And the battery performance is improved.

Description

Technical Field

[0001] The present application belongs to the field of battery processing technology, and in particular relates to a laminated battery cell and a preparation device thereof. Background Art

[0002] The stacked cells of lithium batteries are prepared using a Z-type stacking process. The Z-type stacking process is to compound the positive electrode sheet, negative electrode sheet and separator through a thermal composite process, and then stack them in a Z shape to form a core package.

[0003] At present, the technology for compounding pole pieces and diaphragms is to coat hot-melt adhesive on the diaphragm, and then use a hot pressing process to bond the diaphragm and the pole piece together with the adhesive. However, during the hot pressing process, the temperature of the composite roller exceeds 50°C and the pressure needs to exceed 1.2T. Only under the action of high temperature and high pressure can the diaphragm and the pole piece be pressed together. However, the rubber particles on the diaphragm will be flattened, resulting in a decrease in the air permeability of the diaphragm, affecting the liquid absorption effect of the battery. After full charge, the battery interface is prone to purple spots, black spots and other poor interface conditions, resulting in poor battery performance. Utility Model Content

[0004] The embodiments of the present application provide a laminated battery cell and a manufacturing device thereof to solve the problem of poor battery performance caused by high temperature and high pressure thermal composite electrodes and diaphragms during the existing laminated battery cell processing.

[0005] In a first aspect, an embodiment of the present application provides a laminated battery cell, which is prepared by folding a battery cell structure, and the battery cell structure includes:

[0006] a first pole piece, wherein a first pole lug is provided on the first pole piece;

[0007] A diaphragm, wherein the first pole piece is disposed on one side of the diaphragm, the first pole piece is connected to the diaphragm via a conductive adhesive at room temperature and pressure, and the first pole tab extends out of the diaphragm;

[0008] A second pole piece is provided with a second pole tab, the second pole piece is arranged on the side of the diaphragm away from the first pole piece, the second pole piece is connected to the diaphragm through the normal temperature and pressure conductive adhesive, and the second pole tab extends out of the diaphragm.

[0009] Optionally, two diaphragms are provided, namely a first diaphragm and a second diaphragm, the first pole piece is located between the first diaphragm and the second diaphragm, the two sides of the first pole piece are respectively connected to the first diaphragm and the second diaphragm through the conductive adhesive at normal temperature and normal pressure, the second pole piece is provided on the side of the first diaphragm facing away from the first pole piece and the side of the second diaphragm facing away from the first pole piece, and along the length direction of the diaphragm, multiple second pole pieces are alternately provided on the first diaphragm and the second diaphragm.

[0010] Optionally, the first electrode is a negative electrode, and the second electrode is a positive electrode.

[0011] Optionally, the negative electrode sheet is a continuous electrode sheet, and the negative electrode sheet corresponds to a plurality of positive electrode sheets.

[0012] Optionally, a diaphragm is provided, and the first electrode plate and the second electrode plate are alternately arranged on both sides of the diaphragm, the first electrode plate is located on one side of the diaphragm, and one side of the first electrode plate is connected to one side of the diaphragm through the conductive adhesive at room temperature and normal pressure, and the second electrode plate is located on the other side of the diaphragm, and one side of the second electrode plate is connected to the other side of the diaphragm through the conductive adhesive at room temperature and normal pressure.

[0013] Optionally, the room temperature and pressure conductive adhesive is PVDF-HFP.

[0014] In a second aspect, an embodiment of the present application provides a device for preparing a laminated battery cell, comprising:

[0015] A first pole piece preparation unit, used for preparing a first pole piece;

[0016] a first glue spraying mechanism, disposed downstream of the first pole piece preparation unit, for spraying a normal temperature and pressure conductive adhesive onto the surface of the first pole piece;

[0017] a diaphragm unwinding mechanism, disposed downstream of the first glue spraying mechanism, for conveying the diaphragm;

[0018] a first composite mechanism, disposed downstream of the diaphragm unwinding mechanism, comprising two first pressure rollers disposed opposite to each other, wherein the first electrode sheet and the diaphragm pass through the first pressure rollers to produce a first composite tape, and the pressure applied by the first pressure rollers is P1, wherein 0.05T≤P1≤0.1T;

[0019] A second pole piece preparation unit, provided downstream of the first composite mechanism, for preparing a second pole piece;

[0020] a second adhesive spraying mechanism, disposed downstream of the second pole piece preparation unit, for spraying the normal temperature and pressure conductive adhesive onto the surface of the second pole piece connected to the first composite tape;

[0021] A second composite mechanism is provided downstream of the second glue spraying mechanism and includes two second pressure rollers arranged opposite to each other. The first composite tape and the second pole piece pass through the second pressure rollers to prepare a battery cell structure. The pressure applied by the second pressure rollers is P2, where 0.05T≤P2≤0.1T;

[0022] The folding mechanism is used to fold the battery cell structure to prepare a laminated battery cell.

[0023] Optionally, two first glue spraying mechanisms are provided, and the two first glue spraying mechanisms are used to spray the normal temperature and pressure conductive adhesive onto both side surfaces of the first pole piece respectively.

[0024] Optionally, two second glue spraying mechanisms are provided, and the two second glue spraying mechanisms are respectively used to spray the normal temperature and pressure conductive adhesive onto one side surface of the second pole piece on both sides of the diaphragm.

[0025] Optionally, the spraying area of ​​the normal temperature and pressure conductive adhesive on the first pole piece is S1, wherein 0.8A1≤S1≤A1, and A1 is the area of ​​one side surface of the first pole piece;

[0026] And / or, the spraying area of ​​the normal temperature and pressure conductive adhesive on the second pole piece is S2, wherein 0.8A2≤S2≤A2, and A2 is the area of ​​one side surface of the second pole piece.

[0027] Optionally, the thickness of the conductive adhesive sprayed on the first pole piece at room temperature and pressure is D1, wherein 1 μm≤D1≤2 μm;

[0028] And / or, the conductive adhesive sprayed on the second pole piece at room temperature and pressure has a thickness D2, wherein 1 μm≤D2≤2 μm.

[0029] Optionally, the room temperature and pressure conductive adhesive is PVDF-HFP.

[0030] The embodiments of the present application provide a laminated battery cell and a preparation device thereof. The laminated battery cell includes a first electrode, a second electrode and a diaphragm. The first electrode and the diaphragm are compositely connected by a conductive adhesive at room temperature and normal pressure. The second electrode and the diaphragm are compositely connected by a conductive adhesive at room temperature and normal pressure. The conductive adhesive at room temperature and normal pressure is PVDF-HFP. The conductive adhesive at room temperature and normal pressure has good adhesion properties at room temperature and normal pressure, and also has good conductivity. It overcomes the problem of poor battery performance caused by high temperature and high pressure thermal composite electrode and diaphragm in the existing laminated battery processing process, improves the battery's liquid absorption effect and poor interface, and improves battery performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] To more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0032] For a more complete understanding of the present application and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings in which like reference numerals indicate like parts throughout the several views.

[0033] Figure 1 A cross-sectional view of a first form of a laminated battery cell provided in an embodiment of the present application.

[0034] Figure 2 A cross-sectional view of a second form of a laminated battery cell provided in an embodiment of the present application.

[0035] Figure 3 A cross-sectional view of a third form of a laminated battery cell provided in an embodiment of the present application.

[0036] Figure 4 A cross-sectional view of a first form of a battery cell structure provided in an embodiment of the present application.

[0037] Figure 5 A cross-sectional view of a second form of a battery cell structure provided in an embodiment of the present application.

[0038] Figure 6 A cross-sectional view of a third form of a battery cell structure provided in an embodiment of the present application.

[0039] Figure 7 A schematic view of a manufacturing device of a laminated battery cell provided in an embodiment of the present application.

[0040] Reference signs are:

[0041] 10, laminated battery cell; 110, first electrode sheet; 120, separator; 121, first separator; 122, second separator; 130, second electrode sheet;

[0042] 100, first electrode sheet manufacturing unit; 200, first glue spraying mechanism; 300, separator unwinding mechanism; 400, first compounding mechanism; 410, first pressure roller; 500, second electrode sheet manufacturing unit; 600, second glue spraying mechanism; 700, second compounding mechanism; 710, second pressure roller; 800, folding mechanism. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0044] Reference is made to Figure 1 , Figure 2 , Figure 3、 Figure 4 、 Figure 5 and Figure 6 The embodiment of the present application provides a laminated battery cell 10, which is prepared by folding a cell structure. The cell structure comprises a first pole piece 110, a diaphragm 120 and a second pole piece 130. The first pole piece 110 is arranged on one side of the diaphragm 120, and the first pole piece 110 is connected with the diaphragm 120 through a normal-temperature and normal-pressure conductive adhesive. The second pole piece 130 is arranged on the side of the diaphragm 120 away from the first pole piece 110, and the second pole piece 130 is connected with the diaphragm 120 through a normal-temperature and normal-pressure conductive adhesive. The first pole piece 110 and the second pole piece 130 are opposite in polarity. The first pole piece 110 is provided with a first tab, and the second pole piece 130 is provided with a second tab. The first tab and the second tab extend out of the diaphragm 120.

[0045] In the embodiment of the present application, the first pole piece 110 and the second pole piece 130 are connected with the diaphragm 120 through a normal-temperature and normal-pressure conductive adhesive. In the process of compounding the first pole piece 110, the second pole piece 130 and the diaphragm 120, high temperature and high pressure are not needed. Under normal temperature and normal pressure (temperature is 25 DEG C, and pressure is 1.01325 Pa), the effect of bonding the first pole piece 110, the second pole piece 130 and the diaphragm 120 can be realized, and the conductive performance is good. The processing process is simple, and the investment in processing equipment is reduced.

[0046] In some embodiments, the normal-temperature and normal-pressure conductive adhesive is PVDF-HFP (polyvinylidene fluoride-hexafluoropropylene).

[0047] In the embodiment of the present application, the first pole piece 110 and the second pole piece 130 are bonded with the diaphragm 120 through PVDF-HFP. PVDF-HFP has good cohesion, and has good bonding effect under normal temperature and normal pressure. The conductivity of PVDF-HFP is as high as 3.2 ms / cm at room temperature, the electrochemical temperature window can reach 5V, the lithium ion migration number is 0.63, and the interface compatibility with lithium metal is good. Therefore, the cycle stability and safety of the lithium battery are improved.

[0048] In some embodiments, referring to Figure 1 and Figure 4Two layers of diaphragms 120 are provided in the cell structure, namely a first diaphragm 121 and a second diaphragm 122. The first diaphragm 121 and the second diaphragm 122 are arranged relative to each other. The first diaphragm 121 and the second diaphragm 122 both extend along the first direction. The first diaphragm 121 and the second diaphragm 122 have the same shape and size. The first pole piece 110 is located between the first diaphragm 121 and the second diaphragm 122. Along the first direction, the first pole piece 110 is arranged at intervals, and both sides of the first pole piece 110 are coated with a normal temperature and normal pressure conductive adhesive. One side of the first pole piece 110 is bonded to the first diaphragm 121 by a normal temperature and normal pressure conductive adhesive, and the other side of the first pole piece 110 is bonded to the second diaphragm 122 by a normal temperature and normal pressure conductive adhesive. The second pole piece 130 is provided on the side of the first diaphragm 121 facing away from the first pole piece 110 and on the side of the second diaphragm 122 facing away from the first pole piece 110. Along the first direction, the second pole pieces 130 located on one side of the first diaphragm 121 and the second pole pieces 130 located on one side of the second diaphragm 122 are alternately arranged in sequence.

[0049] For example, see Figure 1 and Figure 4 The first electrode piece 110 and the second electrode piece 130 are both single electrodes. Multiple first electrode pieces 110 are spaced apart along a first direction, and multiple second electrode pieces 130 are spaced apart along the first direction. The first electrode piece 110 and the second electrode piece 130 are aligned. The first direction is the X-axis direction. When the first electrode piece 110 is a negative electrode piece, the second electrode piece 130 is a positive electrode piece. When the first electrode piece 110 is a positive electrode piece, the second electrode piece 130 is a negative electrode piece.

[0050] See also Figure 4 and Figure 5 , along the first direction, adjacent negative electrode sheets are spaced a certain distance apart. Both sides of the negative electrode sheet are coated with a conductive adhesive at room temperature and pressure, and the two sides of the negative electrode sheet are respectively bonded and connected to the first diaphragm 121 and the second diaphragm 122. One side of the positive electrode sheet is coated with a conductive adhesive at room temperature and pressure, and the positive electrode sheet is bonded and connected to the diaphragm 120 on its side. Along the thickness direction of the negative electrode sheet, the negative electrode sheet and the positive electrode sheet are arranged in alignment. Both the positive electrode sheet and the negative electrode sheet are rectangular sheet structures, the length dimension of the positive electrode sheet is smaller than the length dimension of the negative electrode sheet, and the width dimension of the positive electrode sheet is smaller than the width dimension of the negative electrode sheet. The projections of all negative electrode sheets in the diaphragm 120 fall within the range of the diaphragm 120.

[0051] In some embodiments, the first electrode 110 is a positive electrode and the second electrode 130 is a negative electrode. Along the first direction, a plurality of positive electrode sheets are arranged in sequence at intervals. The number of second electrode sheets 130 is two more than the number of first electrode sheets 110. Along the thickness direction, the second electrode sheet 130 is arranged in alignment with the first electrode sheet 110, and the projection of the first electrode sheet 110 completely falls within the projection range of the second electrode sheet 130. A conductive adhesive at room temperature and pressure is sprayed on both sides of the positive electrode sheet, and the positive electrode sheet is bonded and connected to the first diaphragm 121 and the second diaphragm 122 on both sides. The negative electrode sheet is arranged on the side of the first diaphragm 121 facing away from the positive electrode sheet and on the side of the second diaphragm 122 facing away from the positive electrode sheet. Along the first direction, the negative electrode sheet on the side of the first diaphragm 121 and the negative electrode sheet on the side of the second diaphragm 122 are arranged alternately.

[0052] In some embodiments, the first electrode 110 is a negative electrode, and the second electrode 130 is a positive electrode.

[0053] For example, see Figure 2 and Figure 5 , along the first direction, adjacent negative electrodes are connected. Multiple first electrodes 110 are connected in a long strip structure, and the first electrode 110 is a continuous structure. The size of the first electrode 110 is smaller than the size of the diaphragm 120. The projection of the first electrode 110 on the diaphragm 120 falls completely within the range of the diaphragm 120. Both sides of the first electrode 110 are coated with a conductive adhesive at room temperature and normal pressure, and the first electrode 110 is bonded to the diaphragm 120. Alternatively, the area on the first electrode 110 that is aligned with the second electrode 130 is coated with a conductive adhesive at room temperature and normal pressure, and the electrode 110 is bonded to the diaphragm 120 within the coating range. Along the first direction, the projections of the positive electrode on the first diaphragm 120 are arranged in sequence, and the distance between any adjacent positive electrode sheets is the same.

[0054] In some embodiments, see Figure 3 and Figure 6 The cell structure includes a plurality of first electrode sheets 110, a diaphragm 120, and a plurality of second electrode sheets 130. The first electrode sheet 110 is located on one side of the diaphragm 120 and is spaced apart along a first direction. The second electrode sheet 130 is located on the other side of the diaphragm 120 and is spaced apart along the first direction. The first electrode sheets 110 and the second electrode sheets 130 are alternately spaced apart along the first direction. One side of the first electrode sheet 110 is connected to one side of the diaphragm 120 by a conductive adhesive at room temperature and pressure. The second electrode sheet 130 is located on the other side of the diaphragm 120 and is connected to the other side of the diaphragm 120 by a conductive adhesive at room temperature and pressure.

[0055] See also Figure 7The embodiment of the present application also provides a preparation device for a laminated battery cell, including a first electrode preparation unit 100, a first glue spraying mechanism 200, a diaphragm unwinding mechanism 300, a first composite mechanism 400, a second electrode preparation unit 500, a second glue spraying mechanism 600, a second composite mechanism 700 and a folding mechanism 800 arranged in sequence along the production line.

[0056] In this embodiment, see Figure 7 , the first electrode sheet preparation unit 100 is used to prepare the first electrode sheet 110. The first electrode sheet preparation unit 100 includes an unwinding mechanism and a cutting mechanism, and the electrode sheet material roll is wound on the unwinding mechanism. When the first electrode sheet 110 is a positive electrode sheet, the corresponding unwinding mechanism is wound with a positive electrode sheet material roll. When the first electrode sheet 110 is a negative electrode sheet, the corresponding unwinding mechanism is wound with a negative electrode sheet material roll. The cutting mechanism is used to cut the material roll into multiple first electrode sheets 110. When the first electrode sheet 110 is a positive electrode sheet, the cutting mechanism cuts out multiple positive electrode sheets. When the first electrode sheet 110 is a negative electrode sheet, the cutting mechanism cuts out multiple negative electrode sheets or a continuous negative electrode sheet.

[0057] In this embodiment, see Figure 7 The first adhesive spraying mechanism 200 is disposed downstream of the first electrode sheet preparation unit 100. The first adhesive spraying mechanism 200 is used to spray a normal temperature and pressure conductive adhesive onto the surface of the cut first electrode sheet 110 that is connected to the diaphragm 120. In some embodiments, the normal temperature and pressure conductive adhesive is PVDF-HFP.

[0058] In this embodiment, see Figure 7 , the diaphragm unwinding mechanism 300 is arranged downstream of the first glue spraying mechanism 200. When two diaphragms 120 are provided, the diaphragm unwinding mechanism 300 includes a first diaphragm unwinding roll, a second diaphragm unwinding roll and a cutting mechanism. The first diaphragm unwinding roll and the second diaphragm unwinding roll are wound with diaphragm rolls. The first diaphragm unwinding roll is used to unwind the diaphragm roll, which is cut into the first diaphragm 121 by the cutting mechanism. The second diaphragm unwinding roll is used to unwind the diaphragm material, which is cut into the second diaphragm 122 by the cutting mechanism. The first diaphragm unwinding roll is located on one side of the first electrode piece 110, and the second diaphragm unwinding roll is located on the other side of the first electrode piece 110. During the unwinding process of the first diaphragm 121 and the second diaphragm 122, the first diaphragm 121 and the second diaphragm 122 are respectively bonded and connected to the first electrode piece 110.

[0059] In this embodiment, see Figure 7, the first composite mechanism 400 is arranged downstream of the diaphragm unwinding mechanism 300. The first composite mechanism 400 includes two first pressure rollers 410 arranged opposite to each other. The first pressure roller 410 does not need to be heated, and compared with the composite roller, it has a simple structure and is easy to maintain. The first electrode 110 and the diaphragm 120 after bonding are composited into a first composite tape after passing through the first pressure roller 410. The pressure applied by the first pressure roller 410 is P1, where 0.05T≤P1≤0.1T. The value of P1 can be 0.05T, 0.06T, 0.75T, 0.08T, 0.95T, 0.1T or other unlisted values. The pressure applied by the first pressure roller 410 on the diaphragm 120 and the first electrode 110 is relatively small, which reduces the probability of damage to the conductive particles in the conductive adhesive at room temperature and pressure due to excessive pressure, and ensures the conductivity of the conductive adhesive at room temperature and pressure.

[0060] In this embodiment, see Figure 7 , the second electrode sheet preparation unit 500 is arranged downstream of the first composite mechanism 400. The second electrode sheet preparation unit 500 includes an unwinding mechanism and a cutting mechanism, and the electrode sheet material roll is wound on the unwinding mechanism. When the second electrode sheet 130 is a positive electrode sheet, the corresponding electrode sheet material roll is wound with a positive electrode sheet material roll, and when the second electrode sheet 130 is a negative electrode sheet, the corresponding electrode sheet material roll is wound with a negative electrode sheet material roll. The cutting mechanism is used to cut the material roll into a plurality of second electrode sheets 130. The second electrode sheet preparation unit 500 is provided with two unwinding mechanisms and two cutting mechanisms, one of which is located on one side of the first electrode sheet 110. The other unwinding mechanism and cutting mechanism are located on the other side of the first electrode sheet 110.

[0061] In this embodiment, see Figure 7 The second glue spraying mechanism 600 is disposed downstream of the second electrode preparation unit 500. Two second glue spraying mechanisms 600 are provided. One second glue spraying mechanism 600 is disposed on one side of the first electrode 110, and the other second glue spraying mechanism 600 is disposed on the other side of the first electrode 110. One second glue spraying mechanism 600 is used to spray a normal temperature and normal pressure conductive adhesive onto the surface of the second electrode 130 on the side of the first diaphragm 121. The other second glue spraying mechanism 600 is used to spray a normal temperature and normal pressure conductive adhesive onto the surface of the second electrode 130 on the side of the second diaphragm 122. In some embodiments, the normal temperature and normal pressure conductive adhesive is PVDF-HFP.

[0062] In this embodiment, see Figure 7, the second composite mechanism 700 is arranged downstream of the second glue spraying mechanism 600. The second composite mechanism 700 includes two second pressure rollers 710 arranged opposite to each other. The first composite tape and the second pole piece 130 are composited into a battery core structure after passing through the second pressure roller 710. The pressure applied by the second pressure roller 710 is P2, where 0.05T≤P2≤0.1T. The value of P2 can be 0.05T, 0.06T, 0.75T, 0.08T, 0.95T, 0.1T or other unlisted values. The pressure applied by the second pressure roller 710 on the second pole piece 130 and the first composite tape is relatively small, which reduces the probability of damage to the conductive particles in the conductive adhesive at room temperature and pressure due to excessive pressure, thereby ensuring the conductivity of the conductive adhesive at room temperature and pressure.

[0063] In this embodiment, the folding mechanism 800 is disposed downstream of the second composite mechanism 700. The folding mechanism 800 is used to fold the cell structure to produce a laminated cell. For example, the folding mechanism 800 forms a Z-shaped folded cell structure.

[0064] In the embodiment of the present application, the first spray mechanism 200 sprays a normal temperature and normal pressure conductive adhesive onto the surface of the first electrode 110, and the second spray mechanism 600 sprays a normal temperature and normal pressure conductive adhesive onto the surface of the second electrode 130. The first composite mechanism 400 applies a P1 pressure to the first electrode 110 and the diaphragm 120, and the second composite mechanism 700 applies a P2 pressure to the first electrode 110, the diaphragm 120, and the second electrode 130. The first composite mechanism 400 and the second composite mechanism 700 use pressure rollers and do not require heating, so the normal temperature and normal pressure conductive adhesive is not affected by high temperature and high pressure. While ensuring the bonding effect of the diaphragm 120 with the negative electrode and the positive electrode, the conductive performance of the normal temperature and normal pressure conductive adhesive is guaranteed, and the battery performance is good.

[0065] In some embodiments, the first electrode sheet 110 is a negative electrode sheet, and the second electrode sheet 130 is a positive electrode sheet. The first electrode sheet preparation unit 100 can prepare a single negative electrode sheet or a continuous negative electrode sheet. A single negative electrode sheet refers to one negative electrode sheet corresponding to one positive electrode sheet. A continuous negative electrode sheet refers to one negative electrode sheet corresponding to multiple positive electrode sheets.

[0066] In some embodiments, see Figure 7 Two first adhesive spraying mechanisms 200 are provided, each for spraying a normal temperature and normal pressure conductive adhesive onto both sides of the first electrode piece 110. Exemplarily, one first adhesive spraying mechanism 200 is provided on each side of the first electrode piece 110, and both first adhesive spraying mechanisms 200 simultaneously spray the normal temperature and normal pressure conductive adhesive onto both sides of the trimmed first electrode piece 110. In some embodiments, the normal temperature and normal pressure conductive adhesive is PVDF-HFP.

[0067] For example, see Figure 7 Two diaphragms 120 are provided, namely a first diaphragm 121 and a second diaphragm 122. One side of the first electrode piece 110 is bonded to the first diaphragm 121, and the other side is bonded to the second diaphragm 122. Therefore, both sides of the first electrode piece 110 need to be sprayed with a normal temperature and pressure conductive adhesive. In this case, two first adhesive spraying mechanisms 200 are provided to facilitate the adhesive spraying operation.

[0068] In some embodiments, see Figure 7 Two second adhesive spraying mechanisms 600 are provided. The two second adhesive spraying mechanisms 600 are respectively used to spray a normal temperature and normal pressure conductive adhesive on one side of the second electrode piece 130 on both sides of the diaphragm 120. For example, one second adhesive spraying mechanism 600 is provided on one side of the first electrode piece 110, and the other second adhesive spraying mechanism 600 is provided on the other side of the first electrode piece 110. One second adhesive spraying mechanism 600 is used to spray a normal temperature and normal pressure conductive adhesive on the surface of the second electrode piece 130 on the side of the first diaphragm 121.

[0069] In other embodiments, a first glue spraying mechanism 200 and a second glue spraying mechanism 600 are provided. The first glue spraying mechanism 200 is used to spray a normal temperature and pressure conductive adhesive onto the surface of the first electrode 110 that is bonded to the diaphragm 120. The second glue spraying mechanism 600 is used to spray a normal temperature and pressure conductive adhesive onto the surface of the second electrode 130 that is bonded to the diaphragm 120.

[0070] For example, a diaphragm 120 is provided, and a first electrode piece 110 is bonded to one side of the diaphragm 120 using a conductive adhesive at room temperature and pressure, and a second electrode piece 130 is bonded to the other side of the diaphragm 120 using a conductive adhesive at room temperature and pressure. The first electrode pieces 110 and the second electrode pieces 130 are alternately arranged along the length of the diaphragm 120.

[0071] In some embodiments, the spraying area of ​​the normal temperature and pressure conductive adhesive on the first electrode piece 110 is S1, where 0.8A1≤S1≤A1, and A1 is the area of ​​one side surface of the first electrode piece 110. The value of S1 can be 0.8A1, 0.9A1, A1, or other unspecified values.

[0072] In the embodiment of the present application, the glue spraying area of ​​the first pole piece 110 occupies 80% or more of the surface of one side of the first pole piece 110 . The glue spraying area is large, the first pole piece 110 and the diaphragm 120 are firmly bonded, and the conductivity of the conductive adhesive at room temperature and pressure is not affected.

[0073] In some embodiments, the sprayed area of ​​the normal temperature and pressure conductive adhesive on the second electrode piece 130 is S2, where 0.8A2≤S2≤A2, and A2 is the area of ​​one side surface of the second electrode piece 130. The value of S2 can be 0.8A2, 0.9A2, A2, or other unspecified values.

[0074] In the embodiment of the present application, the glue spraying area of ​​the second pole piece 130 occupies 80% or more of the surface of one side of the second pole piece 130 . The larger the glue spraying area, the second pole piece 130 is firmly bonded to the diaphragm 120 , and does not affect the conductivity of the conductive adhesive at room temperature and pressure.

[0075] In some embodiments, the thickness of the conductive adhesive sprayed on the first electrode 110 at room temperature and pressure is D1, where 1 μm ≤ D1 ≤ 2 μm. The value of D1 can be 1 μm, 1.2 μm, 1.5 μm, 1.7 μm, 1.8 μm, 1.9 μm, 2 μm, or other unspecified values.

[0076] In some embodiments, the thickness of the conductive adhesive sprayed on the second electrode 130 at room temperature and pressure is D2, where 1 μm ≤ D2 ≤ 2 μm. The value of D2 can be 1 μm, 1.2 μm, 1.5 μm, 1.7 μm, 1.8 μm, 1.9 μm, 2 μm, or other unspecified values. The value of D2 can be the same as or different from the value of D1.

[0077] The spraying thickness of the normal temperature and normal pressure conductive adhesive on the first pole piece 110 and the second pole piece 130 is moderate, which meets the performance requirements of bonding, conductivity, etc., while reducing the probability of glue overflow after passing through the pressure roller due to excessive spraying of the normal temperature and normal pressure conductive adhesive.

[0078] The present invention also provides a method for preparing a laminated battery cell, comprising the following steps:

[0079] S1, preparing a first pole piece 110 and a second pole piece 130;

[0080] S2, spraying a normal temperature and pressure conductive adhesive on both sides of the first electrode piece 110, compositely connecting the first electrode piece 110 and the two layers of the diaphragm 120, spraying a normal temperature and pressure conductive adhesive on one side of the second electrode piece 130, compositely connecting the second electrode piece 130 and the side of the diaphragm 120 facing away from the first electrode piece 110, to prepare a battery cell structure;

[0081] S3, fold the battery cell structure to prepare a laminated battery cell.

[0082] In the embodiment of the present application, the first electrode piece 110 and the second electrode piece 130 can be prepared simultaneously or separately, and the preparation of the first electrode piece 110 and the second electrode piece 130 is completed before the first electrode piece 110 and the second electrode piece 130 are bonded to the diaphragm 120.

[0083] In some embodiments, the normal temperature and pressure conductive adhesive is PVDF-HFP;

[0084] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0085] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more features.

[0086] The above is a detailed introduction to the laminated battery cells and their preparation equipment provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, based on the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A laminated battery cell (10), characterized in that: The laminated battery cell is prepared by folding the battery cell structure, and the battery cell structure includes: A first pole piece (110), wherein a first pole lug is provided on the first pole piece (110); A diaphragm (120), wherein the first pole piece (110) is arranged on one side of the diaphragm (120), the first pole piece (110) and the diaphragm (120) are connected via a normal temperature and pressure conductive adhesive, and the first pole tab extends outside the diaphragm (120); A second pole piece (130) is provided with a second pole tab, the second pole piece (130) is arranged on a side of the diaphragm (120) away from the first pole piece (110), the second pole piece (130) is connected to the diaphragm (120) through the normal temperature and normal pressure conductive adhesive, and the second pole tab extends outside the diaphragm (120).

2. The laminated battery core (10) according to claim 1, characterized in that: Two diaphragms (120) are provided, namely a first diaphragm (121) and a second diaphragm (122); the first pole piece (110) is located between the first diaphragm (121) and the second diaphragm (122); both sides of the first pole piece (110) are connected to the first diaphragm (121) and the second diaphragm (122) respectively through the normal temperature and normal pressure conductive adhesive; the second pole piece (130) is provided on a side of the first diaphragm (121) facing away from the first pole piece (110) and a side of the second diaphragm (122) facing away from the first pole piece (110); along the length direction of the diaphragm (120), a plurality of second pole pieces (130) are alternately provided on the first diaphragm (121) and the second diaphragm (122).

3. The laminated battery core (10) according to claim 2, characterized in that: The first pole piece (110) is a negative pole piece, and the second pole piece (130) is a positive pole piece.

4. The laminated battery core (10) according to claim 3, characterized in that: The negative electrode sheet is a continuous electrode sheet, and the negative electrode sheet corresponds to a plurality of positive electrode sheets.

5. The laminated battery core (10) according to claim 1, characterized in that: A diaphragm (120) is provided, and the first pole piece (110) and the second pole piece (130) are alternately arranged on both sides of the diaphragm (120), the first pole piece (110) is located on one side of the diaphragm (120), and one side of the first pole piece (110) is connected to one side of the diaphragm (120) through the conductive adhesive at room temperature and normal pressure, and the second pole piece (130) is located on the other side of the diaphragm (120), and one side of the second pole piece (130) is connected to the other side of the diaphragm (120) through the conductive adhesive at room temperature and normal pressure.

6. The laminated battery core (10) according to any one of claims 1 to 5, characterized in that: The normal temperature and pressure conductive adhesive is PVDF-HFP.

7. A device for preparing a laminated battery cell, characterized in that: include: A first pole piece preparation unit (100), used for preparing a first pole piece (110); a first glue spraying mechanism (200), arranged downstream of the first pole piece preparation unit (100), for spraying a normal temperature and pressure conductive adhesive onto the surface of the first pole piece (110); a diaphragm unwinding mechanism (300), disposed downstream of the first glue spraying mechanism (200), for conveying the diaphragm (120); A first composite mechanism (400) is arranged downstream of the diaphragm unwinding mechanism (300), and comprises two first pressure rollers (410) arranged opposite to each other. After the first pole piece (110) and the diaphragm (120) pass through the first pressure rollers (410), a first composite tape is prepared. The pressure applied by the first pressure rollers (410) is P1, wherein 0.05T≤P1≤0.1T; A second pole piece preparation unit (500), disposed downstream of the first composite mechanism (400), for preparing a second pole piece (130); a second adhesive spraying mechanism (600), arranged downstream of the second pole piece preparation unit (500), for spraying the normal temperature and pressure conductive adhesive onto the surface of the second pole piece (130) connected to the first composite tape; A second composite mechanism (700) is arranged downstream of the second glue spraying mechanism (600), and comprises two second pressure rollers (710) arranged opposite to each other, wherein the first composite tape and the second pole piece (130) pass through the second pressure rollers (710) to prepare a battery cell structure, and the pressure applied by the second pressure rollers (710) is P2, wherein 0.05T≤P2≤0.1T; A folding mechanism (800) is used for folding the battery cell structure to prepare a laminated battery cell (10) as claimed in any one of claims 1 to 6.

8. The equipment for preparing laminated battery cells according to claim 7, characterized in that: Two first glue spraying mechanisms (200) are provided, and the two first glue spraying mechanisms (200) are used to spray the normal temperature and pressure conductive adhesive onto the two side surfaces of the first pole piece (110) respectively.

9. The equipment for preparing laminated battery cells according to claim 8, characterized in that: Two second glue spraying mechanisms (600) are provided, and the two second glue spraying mechanisms (600) are respectively used to spray the normal temperature and pressure conductive adhesive onto one side surface of the second pole piece (130) on both sides of the diaphragm (120).

10. The equipment for preparing laminated battery cells according to claim 7, characterized in that: The spraying area of ​​the normal temperature and normal pressure conductive adhesive on the first pole piece (110) is S1, wherein 0.8A1≤S1≤A1, and A1 is the area of ​​one side surface of the first pole piece (110); Alternatively, the spraying area of ​​the normal temperature and normal pressure conductive adhesive on the second pole piece (130) is S2, wherein 0.8A2≤S2≤A2, and A2 is the area of ​​one side surface of the second pole piece (130).

11. The equipment for preparing laminated battery cells according to claim 7, characterized in that: The thickness of the conductive adhesive sprayed on the first pole piece (110) at room temperature and pressure is D1, wherein 1 μm≤D1≤2 μm; And / or, the thickness of the conductive adhesive sprayed on the second pole piece (130) at room temperature and pressure is D2, wherein 1 μm≤D2≤2 μm.

12. The equipment for preparing laminated battery core according to any one of claims 7 to 11, characterized in that: The normal temperature and pressure conductive adhesive is PVDF-HFP.

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