Adhesive tape and secondary battery

Abstract

The utility model relates to the field of rechargeable batteries, in particular to gummed paper and a secondary battery, and the gummed paper comprises a first bonding layer, a liquid storage expansion layer and a second bonding layer which are sequentially stacked, the liquid storage expansion layer comprises liquid storage pores, and the liquid storage pores are used for absorbing and storing electrolyte; the first bonding layer is used for being bonded with a to-be-processed battery cell; and the second bonding layer is used for bonding with a protective shell corresponding to the to-be-processed battery cell. According to the utility model, the battery cell mounting speed is increased, on one hand, more electrolyte can be stored, on the other hand, wrinkles and bubbles caused by uneven initial rubberizing are discharged, the compression consistency of the formed battery cell is improved, the interface is improved, the thickness is increased, the connection stability between the battery cell to be processed and the protective shell is greatly improved, and the service life of the battery cell is prolonged. Buffering is provided between the two; and moreover, along with the charging and discharging circulation of the battery, the to-be-treated battery core can extrude the gummed paper, so that the electrolyte in the liquid storage expansion layer in the gummed paper is released, and the cycle performance of the battery is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of rechargeable battery, in particular to a kind of rubber paper and secondary battery. BACKGROUND

[0002] With the continuous improvement of science and technology, lithium batteries are also gradually used in various industries. In the existing cell manufacturing technology, after the positive and negative pole pieces and the isolation film are stacked to obtain a bare cell, the tabs need to be welded and placed in a protective shell for fixation and packaging.

[0003] Currently, in order to fix the cell in the protective shell, it is common to attach double-sided tape on the surface of the cell for subsequent welding. The surface of the cell is connected to the surface of the protective shell by the double-sided tape. In order to ensure the smooth entry of the cell into the shell, the thickness of the double-sided tape is usually thinned to prevent the cell surface adhered to the double-sided tape from being scratched by the inner wall of the protective shell. However, this will result in a gap between the double-sided tape and the protective shell, making the double-sided tape unable to effectively bind the cell and the protective shell. During subsequent use of the battery, the cell is prone to displacement due to falling, reducing the working stability and service life of the battery. On the other hand, if the double-sided tape has too much reserved thickness, it will hinder the smooth entry of the cell into the shell and make it difficult to weld the shell. Finally, the large-area setting of double-sided tape on the surface of the cell will reduce the space for storing electrolyte, leading to insufficient electrolyte during the later stage of battery cycling and accelerating the decline of battery cycling performance.

[0004] Therefore, how to balance the convenience of installation and the stability of the cell in the protective shell, while slowing down the decline of the battery's cycling performance, is a problem that needs to be solved by those skilled in the art. UTILITY MODEL CONTENTS

[0005] The utility model aims to provide a kind of rubber paper and secondary battery, to solve the problem that installation convenience and the stability of the cell in the protective shell cannot be considered in the prior art, while the cycling performance of the battery declines too fast.

[0006] To solve the above technical problems, the utility model provides a kind of rubber paper, including first adhesive layer, liquid storage expansion layer, second adhesive layer that are sequentially laminated;

[0007] The liquid storage expansion layer includes liquid storage pores, which are used to absorb and store electrolyte.

[0008] The first adhesive layer is used to adhere to the cell to be processed.

[0009] The second adhesive layer is used to adhere to the protective shell corresponding to the cell to be processed.

[0010] Optionally, the adhesive paper further comprises a fireproof layer stacked with the liquid storage and expansion layer.

[0011] Optionally, the adhesive paper comprises two fireproof layers.

[0012] One of the fireproof layers is arranged between the first adhesive layer and the liquid storage and expansion layer, and the other fireproof layer is arranged between the second adhesive layer and the liquid storage and expansion layer.

[0013] Optionally, the fireproof layer is at least one of an aluminum oxide layer or a mica layer.

[0014] Optionally, the liquid storage and expansion layer is a synthetic resin layer.

[0015] Optionally, the second adhesive layer is a hot melt adhesive layer.

[0016] Optionally, the adhesive paper is provided with a plurality of through holes on the surface thereof.

[0017] A secondary battery comprising a battery cell, a protective shell, and any one of the adhesive papers.

[0018] Optionally, the battery cell is a laminated battery cell; the laminated battery cell has a first laminated surface and a second laminated surface perpendicular to the stacking direction; and further has a side surface sandwiched between the first laminated surface and the second laminated surface and connected to the first laminated surface and the second laminated surface.

[0019] The secondary battery comprises a plurality of adhesive papers, which are divided into first type adhesive papers and / or second type adhesive papers.

[0020] The first type adhesive papers are arranged on the first laminated surface or the second laminated surface.

[0021] The second type adhesive papers sequentially span the first laminated surface, the side surface, and the second laminated surface.

[0022] Optionally, the battery cell is a jelly-roll battery cell; the jelly-roll battery cell has a first open surface and a second open surface perpendicular to the winding axis.

[0023] The first open surface is provided with a tab.

[0024] Further has a winding side surface sandwiched between the first open surface and the second open surface and connected to the first open surface and the second open surface.

[0025] The winding side surface comprises a winding tail of the jelly-roll battery cell.

[0026] The winding core comprises a plurality of adhesive papers, the adhesive papers are divided into third adhesive papers and / or fourth adhesive papers;

[0027] The third adhesive papers are arranged on the winding side surface and fix the winding tail part on the winding side surface;

[0028] The fourth adhesive papers are arranged on the second open surface.

[0029] The utility model discloses a liquid storage expansion layer that can absorb electrolyte expansion is additionally arranged between the two adhesive layers of adhesive paper, so that the to-be-processed battery is put into the protective shell (the process of entering the shell is in the state of not injecting liquid, and the liquid storage expansion layer does not absorb electrolyte expansion), therefore the thickness of adhesive paper is thin, does not scratch the inner wall of the protective shell, and the installation speed is improved. In the process of injecting electrolyte into the protective shell subsequently, due to the sponge structure of the liquid storage expansion layer, the adhesive paper absorbs liquid and expands, on one hand, helps to store more electrolyte, on the other hand, expels the wrinkles and bubbles caused by uneven initial adhesive, improves the consistency of the formed battery under pressure, improves the interface, and the thickness is increased, also exerts pre-tension on the to-be-processed battery and the protective shell, makes the surface of the two more closely adhere, greatly improves the connection stability between the to-be-processed battery and the protective shell, provides buffering between the two, so that the battery is not easy to fall off and the local stress concentration caused by the local failure of the battery when falling and impacting subsequently. In addition, with the charge and discharge cycle of the battery, the overall thickness of the to-be-processed battery will also increase, and the increase of the thickness of the to-be-processed battery will squeeze the adhesive paper, so that the electrolyte in the liquid storage expansion layer in the adhesive paper is released, providing fresh electrolyte for the later stage of the battery life, improving the cycle performance and service life of the battery. The utility model also provides a secondary battery with the above beneficial effects. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical scheme of the embodiments of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creating creative labor.

[0031] Figure 1 The structure schematic diagram of one specific embodiment of the adhesive paper provided by the utility model is shown in the figure.

[0032] Figure 2 The structure top view of one specific embodiment of the adhesive paper provided by the utility model is shown in the figure.

[0033] Figure 3Another specific embodiment structure diagram of the adhesive paper provided by the utility model is shown in the figure.

[0034] Figure 4 Another specific embodiment structure diagram of the adhesive paper provided by the utility model is shown in the figure.

[0035] Figure 5 Another specific embodiment structure diagram of the secondary battery provided by the utility model is shown in the figure.

[0036] Figure 6 Another specific embodiment structure diagram of the secondary battery provided by the utility model is shown in the figure.

[0037] In the figure, including 10-first adhesive layer, 20-liquid storage expansion layer, 30-second adhesive layer, 40-flame retardant layer, 01-through hole, 100-stacked core, 101-first type adhesive paper, 102-second type adhesive paper, 200-wound core, 203-third type adhesive paper, 204-fourth type adhesive paper. Specific embodiments

[0038] In order to make the person skilled in the art better understand the utility model scheme, the utility model is further described in detail below in combination with the drawings and specific embodiments. Obviously, the described embodiments are only part of the embodiments of the utility model, not all. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor belong to the scope of protection of the utility model.

[0039] The core of the utility model is to provide an adhesive paper, and a specific embodiment structure diagram thereof is shown in the figure as Figure 1 Specific embodiment one is shown in the figure, which comprises first adhesive layer 10, liquid storage expansion layer 20 and second adhesive layer 30 arranged in sequence.

[0040] The liquid storage expansion layer 20 comprises liquid storage pores, which are used to absorb and store electrolyte.

[0041] The first adhesive layer 10 is used to adhere to the to-be-processed core.

[0042] The second adhesive layer 30 is used to adhere to the corresponding protective shell of the to-be-processed core.

[0043] The liquid storage expansion layer 20 has a plurality of three-dimensional porous structures inside, which will expand in the thickness direction after absorbing the electrolyte. Preferably, the liquid storage expansion layer 20 is a synthetic resin layer. The synthetic resin layer swells significantly, and the volume will expand significantly after absorbing the electrolyte, which can better fix the battery cell. The good mechanical properties and insulation of the synthetic resin can also improve the safety of the battery in use. Of course, the liquid storage expansion layer 20 can also be made of other materials, which is not limited in the utility model.

[0044] Of course, before the adhesive paper is pasted on the corresponding battery cell, a release paper can be arranged on the surface of the first adhesive layer 10 to protect the surface of the first adhesive layer 10. Preferably, the first adhesive layer 10 is a pressure-sensitive adhesive layer.

[0045] The combination of the pressure-sensitive adhesive and the release paper can ensure that the adhesive property of the adhesive paper will not be lost during storage and transportation, and greatly reduce the probability of accidental adhesion to other surfaces, which is convenient to use. The first adhesive layer can also be an acrylic adhesive layer or other adhesive layer, which is not limited in the utility model.

[0046] In addition, as a specific embodiment, the second adhesive layer 30 is a hot melt adhesive layer. The hot melt adhesive layer as the second adhesive layer 30 can be simultaneously adhered when the battery cell is put into the protective shell for formation, so as to avoid accidental adhesion of the second adhesive layer 30 to other surfaces during storage and transportation, and improve the stability of adhesion and the working stability of the battery.

[0047] As a preferred embodiment, the surface of the adhesive paper is provided with a plurality of through holes 01. The surface of the adhesive paper can be drawn as shown in Figure 2 , Figure 2 It can be seen that the adhesive paper is penetrated by a plurality of through holes 01 (the shape of the through hole 01 is outlined by a dashed line in Figure 1 ), which exposes the liquid storage expansion layer 20 on the inner wall of each through hole 01, so that the contact area of the liquid storage expansion layer 20 with the electrolyte is greatly increased, the liquid absorption speed and storage rate of the liquid storage expansion layer 20 are improved, and the area of the liquid storage expansion layer 20 that is not soaked by the electrolyte is avoided due to the small contact area. At the same time, it can also assist in removing the gas generated during the formation of the battery.

[0048] The utility model discloses a sponge -like structure of the liquid storage expansion layer 20, and the glue paper absorbs liquid expansion, one hand helps to store more electrolyte, the other hand discharges the wrinkle and bubble caused by the initial gluing uneven, improves the consistency of the formation cell under pressure, improves the interface, and the thickness increases, also exerts the pretension on the both of the cell to be handled and the protective shell, makes the surface of both more closely, greatly improves the connection stability between the cell to be handled and the protective shell, and provides the buffer between both, when the battery encounters the drop and the impact in succession, the cell is not easy to fall off and the local stress concentration causes the local failure of the battery, and the battery is charged and discharged, and the overall thickness of the cell to be handled also will increase constantly, and the increase of the thickness of the cell to be handled will extrude the glue paper, and the electrolyte in the liquid storage expansion layer 20 in the glue paper is released, provides the fresh electrolyte for the later stage of battery life, improves the cycle performance and the service life of battery.

[0049] On the basis of the first specific embodiment, the laminated structure of the glue paper is further improved to obtain the second specific embodiment, and the corresponding structural diagram is as shown in Figure 3 The first adhesive layer 10, the liquid storage expansion layer 20 and the second adhesive layer 30 are sequentially laminated.

[0050] The liquid storage expansion layer 20 includes liquid storage pores, and the liquid storage pores are used to absorb and store electrolyte.

[0051] The first adhesive layer 10 is used to be bonded with the cell to be handled.

[0052] The second adhesive layer 30 is used to be bonded with the protective shell corresponding to the cell to be handled.

[0053] Further include the fire -retardant layer 40 that is laminated with the liquid storage expansion layer 20.

[0054] The difference between the specific embodiment and the above specific embodiment is that the fire -retardant layer 40 is additionally arranged in the specific embodiment, and the rest structures are same with the above specific embodiment, and here will not be expanded.

[0055] The fire -retardant layer 40 is additionally arranged in the preferred embodiment, and the glue paper is often attached to the surface of each direction of the battery cell, so that the glue paper has the fire -retardant effect, can inhibit the thermal runaway of the cell, greatly improves the working safety of the battery, in addition, the granular fire -retardant layer 40 is embedded between the glue layer and the expansion layer, and the mechanical strength and the processing performance of the glue paper are improved, and the fire -retardant layer 40 also plays the role of partial heat insulation.Figure 3 The fireproof layer 40 is arranged between the first adhesive layer 10 and the liquid storage expansion layer 20, and can also be arranged at other positions, which is not limited in the utility model.

[0056] Further, the adhesive paper comprises two fireproof layers 40.

[0057] One of the fireproof layers 40 is arranged between the first adhesive layer 10 and the liquid storage expansion layer 20, and the other fireproof layer 40 is arranged between the second adhesive layer 30 and the liquid storage expansion layer 20.

[0058] Please refer to Figure 4 In the preferred embodiment, the fireproof layer 40 is arranged on both sides of the liquid storage expansion layer 20, which increases the structural strength of the adhesive paper and further improves the inhibition capacity of the thermal runaway of the battery cell.

[0059] Further, the fireproof layer 40 is at least one of an aluminum oxide layer or a mica layer. The aluminum oxide layer and the mica layer are light in weight, strong in plasticity and good in fireproof effect, and other types of fireproof layers 40 can also be selected according to actual needs, which is not limited in the utility model.

[0060] The utility model also provides a secondary battery, and a structure schematic diagram of one specific embodiment is as shown in Figure 5 and Figure 6 The secondary battery comprises a battery cell, a protective shell and the adhesive paper.

[0061] Of course, the secondary battery also has various structural types, and as a specific embodiment, the battery cell is a laminated battery cell 100; the laminated battery cell 100 has a first laminated surface and a second laminated surface which are perpendicular to a laminating direction; and further has a side surface which is clamped between the first laminated surface and the second laminated surface and connected with the first laminated surface and the second laminated surface.

[0062] The secondary battery comprises a plurality of adhesive papers, and the adhesive papers are divided into first adhesive papers 101 and / or second adhesive papers 102.

[0063] The first adhesive papers 101 are arranged on the first laminated surface or the second laminated surface.

[0064] The second adhesive papers 102 sequentially cross the first laminated surface, the side surface and the second laminated surface.

[0065] Please see Figure 5 , Figure 5For the cross-sectional view of the embodiment, for the laminated battery in the embodiment, in addition to covering the bottom and top (i.e. the first and second stacking surfaces) of the laminated battery by the first type of adhesive paper 101, the first and second stacking surfaces are connected by the second type of adhesive paper 102, which increases the structural strength of the battery cell.

[0066] As a specific embodiment, the battery cell is a jelly-roll battery cell 200; the jelly-roll battery cell 200 has a first open surface and a second open surface perpendicular to the winding axis;

[0067] The first open surface is used to set the tab;

[0068] It also has a winding side surface sandwiched between the first and second open surfaces and connected to the first and second open surfaces;

[0069] The winding side surface includes the winding tail of the jelly-roll battery cell 200;

[0070] The jelly-roll battery cell 200 includes a plurality of adhesive papers, which are divided into a third type of adhesive paper 203 and / or a fourth type of adhesive paper 204;

[0071] The third type of adhesive paper 203 is arranged on the winding side surface and fixes the winding tail to the winding side surface;

[0072] The fourth type of adhesive paper 204 is arranged on the second open surface.

[0073] See Figure 6 , Figure 6 For the side view of the jelly-roll battery cell 200, the third type of adhesive paper 203 plays a fixing role for the winding tail, and the fourth type of adhesive paper 204 to some extent hinders the leakage of electrolyte in the jelly-roll battery cell 200, ensuring that the capacity of the battery does not decrease under long-term use.

[0074] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method part.

[0075] It should be noted that the relative terms, such as first and second, and the like, are used herein solely to distinguish one entity or action from another, without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprises... " does not, without more limitations, preclude the existence of further identical elements in the process, method, article, or apparatus that comprises the recited element.

[0076] The above has carried on the detailed introduction to the adhesive paper and the secondary battery provided by the utility model. The principle and implementation mode of the utility model are described in this paper by applying specific examples. The above embodiment description is only for helping to understand the method and core idea of the utility model. It should be pointed out that for ordinary skilled persons in the art, without departing from the principle of the utility model, the utility model can be improved and modified in several ways. These improvements and modifications also fall within the protection scope of the utility model claims.

Claims

1. A gummed paper, characterized by, The adhesive paper comprises a first adhesive layer, a liquid storage expansion layer, and a second adhesive layer arranged in sequence. The liquid storage expansion layer comprises liquid storage pores for absorbing and storing electrolyte. The first adhesive layer is used for bonding with a battery cell to be processed. The second adhesive layer is used for bonding with a protective shell corresponding to the battery cell to be processed.

2. The gummed paper as claimed in claim 1, wherein, The adhesive paper further comprises a fire-retardant layer arranged in sequence with the liquid storage expansion layer.

3. The gummed paper as claimed in claim 2, wherein, The adhesive paper comprises two fire-retardant layers. One of the fire-retardant layers is arranged between the first adhesive layer and the liquid storage expansion layer, and the other fire-retardant layer is arranged between the second adhesive layer and the liquid storage expansion layer.

4. The gummed paper as claimed in claim 2, wherein, The fire-retardant layer is at least one of an aluminum oxide layer or a mica layer.

5. The gummed paper as claimed in claim 1, wherein, The liquid storage expansion layer is a synthetic resin layer.

6. The gummed paper of claim 1 wherein, The second adhesive layer is a hot melt adhesive layer.

7. The gummed paper of claim 1 wherein, The adhesive paper is provided with a plurality of through holes on the surface thereof.

8. A secondary battery characterized by comprising: The battery cell, the protective shell, and the adhesive paper according to any one of claims 1 to 7.

9. The secondary battery according to claim 8, wherein The battery cell is a laminated battery cell having a first laminated surface and a second laminated surface perpendicular to a laminating direction, and a side surface sandwiched between the first laminated surface and the second laminated surface and connected to the first laminated surface and the second laminated surface. The secondary battery comprises a plurality of adhesive papers, which are divided into first adhesive papers and / or second adhesive papers. The first adhesive papers are arranged on the first laminated surface or the second laminated surface. The second adhesive papers are arranged in sequence across the first laminated surface, the side surface, and the second laminated surface.

10. The secondary battery according to claim 8, wherein the negative electrode is a lithium metal electrode. The battery cell is a wound battery cell having a first open surface and a second open surface perpendicular to a winding axis. The first open surface is provided with a tab. The wound battery cell further comprises a winding side surface sandwiched between the first open surface and the second open surface and connected to the first open surface and the second open surface. The winding side surface comprises a winding tail of the wound battery cell. The wound battery cell comprises a plurality of adhesive papers, which are divided into third adhesive papers and / or fourth adhesive papers. The third adhesive papers are arranged on the winding side surface and fix the winding tail to the winding side surface. The fourth adhesive papers are arranged on the second open surface.

Images