Laminated electrode body convenient to assemble and battery

Abstract

The utility model discloses a laminated type electrode body convenient to assemble and a battery, and relates to the technical field of batteries, the laminated type electrode body comprises a negative pole assembly and a positive pole piece, the negative pole assembly comprises a negative pole piece and diaphragms, the diaphragms are adhered to the surfaces of the two sides of the negative pole piece through adhesive layers, and the positive pole piece and the negative pole assembly are arranged in a laminated manner. According to the technical scheme provided by the utility model, the diaphragm is bonded with the negative plate in advance, so that the position of the diaphragm in the assembly process can be kept unchanged, and wrinkling is avoided, thereby ensuring that the positive plate and the negative plate are not easy to misplace; the problems that in the Z-shaped lamination process of an existing lamination technology, diaphragms are prone to wrinkling, and pole pieces are prone to dislocation are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a laminated electrode body and a battery which are easy to assemble. Background Art

[0002] The lamination process is an innovative technology that has emerged in recent years in the lithium and sodium battery manufacturing fields. Unlike the traditional winding process, the lamination process uses a Z-shaped stacking method to stack the positive and negative electrodes and the separator to form the battery electrode body. The technical advantages of the lamination process are mainly reflected in its high space utilization and good structural stability. The positive and negative electrodes are stacked, which can more effectively utilize the space inside the battery and improve energy density. However, the separator is generally thin and easily wrinkled during the Z-shaped stacking process, which can easily lead to misalignment between the positive and negative electrodes. Utility Model Content

[0003] The main purpose of the utility model is to provide a laminated electrode body and battery that are easy to assemble, aiming to solve the problems of easy wrinkling of the diaphragm and easy misalignment of the electrode sheets in the Z-shaped lamination process of the existing lamination process.

[0004] To achieve the above-mentioned purpose, the present invention proposes a stacked electrode body that is easy to assemble, and the stacked electrode body includes: a negative electrode assembly, the negative electrode assembly includes a negative electrode sheet and a separator, and the separator is bonded to the surfaces on both sides of the negative electrode sheet through a glue layer; and a positive electrode sheet, and the positive electrode sheet is stacked with the negative electrode assembly.

[0005] In one embodiment, the negative electrode sheet includes a negative electrode body and a negative electrode ear, the negative electrode ear is provided at one end of the negative electrode body, the separator is provided on the surface of the negative electrode body, and the area of the separator is larger than that of the negative electrode body.

[0006] In one embodiment, each side edge of the separator exceeds the corresponding side edge of the negative electrode body, and the exceeding distance is 1.5-2 mm.

[0007] In one embodiment, the negative electrode tab is disposed beyond an edge of the separator.

[0008] In one embodiment, the positive electrode sheet includes a positive electrode body and a positive electrode tab. The positive electrode body and the negative electrode assembly are stacked, and the positive electrode tab and the negative electrode tab are staggered.

[0009] In one embodiment, the adhesive layer is hot-pressed onto the negative electrode sheet and bonded to the separator; wherein the hot-pressing temperature is 80-100° C. and the hot-pressing time is 10-60 min.

[0010] In one embodiment, the negative electrode assemblies are provided in N+1 groups, the positive electrode sheets are provided in N groups, and the positive electrode sheets are provided between two adjacent groups of the negative electrode assemblies.

[0011] In one embodiment, the membrane is a gel membrane.

[0012] In one embodiment, the adhesive layer is made of polyvinylidene fluoride.

[0013] The present invention also provides a battery, comprising the above-mentioned laminated electrode body.

[0014] Compared with the prior art, the present invention provides a laminated electrode body and battery that is easy to assemble and has the following beneficial effects:

[0015] The technical solution of the utility model forms a negative electrode assembly by bonding the diaphragm and the negative electrode sheet together through an adhesive layer, and diaphragms are arranged on both sides of the negative electrode sheet. The diaphragm is bonded to the negative electrode sheet in advance, which can keep the position of the diaphragm unchanged during the stacking process and avoid wrinkling. It can reduce the adjustment and error of the diaphragm during the assembly process, thereby ensuring that the positive electrode sheet and the negative electrode sheet are not easily misaligned, ensuring the stability and safety of the internal structure of the battery, and improving the battery performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0017] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a laminated electrode body of the present utility model;

[0018] Figure 2 This is a front view of an embodiment of a laminated electrode body of the present invention;

[0019] Figure 3 This is a structural diagram of an embodiment of the positive electrode sheet of the present invention;

[0020] Figure 4 This is a schematic structural diagram of an embodiment of the negative electrode sheet of the present invention;

[0021] Figure 5 This is a schematic diagram of the matching structure of the negative electrode sheet and the separator according to one embodiment of the present invention;

[0022] Figure 6 A side view of an embodiment of the negative electrode sheet and separator of the present invention;

[0023] Figure 7 This is a cross-sectional view of an embodiment of the negative electrode sheet and the separator of the present invention;

[0024] Figure 8 A side view of an embodiment of a laminated electrode body of the present invention;

[0025] Figure 9 This is a top view of an embodiment of a laminated electrode body of the present invention.

[0026] Description of Figure Numbers:

[0027] 100. Laminated electrode body; 10. Negative electrode assembly; 11. Negative electrode sheet; 111. Negative electrode body; 112. Negative electrode tab; 12. Separator; 13. Adhesive layer; 20. Positive electrode sheet; 21. Positive electrode body; 22. Positive electrode tab.

[0028] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0031] In addition, the descriptions of "first," "second," etc. in this utility model are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this utility model.

[0032] Please refer to Figures 1 to 9The present invention proposes a stacked electrode body 100 that is easy to assemble. The stacked electrode body 100 includes: a negative electrode assembly 10, the negative electrode assembly 10 includes a negative electrode sheet 11 and a separator 12, the separator 12 is bonded to the surfaces on both sides of the negative electrode sheet 11 through a glue layer 13; and a positive electrode sheet 20, the positive electrode sheet 20 is stacked with the negative electrode assembly 10.

[0033] Specifically, the stacked electrode body 100 includes a negative electrode assembly 10 and a positive electrode sheet 20. The negative electrode assembly 10 is a combination of a negative electrode sheet 11 and a separator 12. The separator 12 is pre-bonded to the surface of the negative electrode sheet 11 through a glue layer 13, and the separator 12 is bonded to the surfaces on both sides of the negative electrode sheet 11. The two layers of separator 12 are respectively bonded to the surfaces on both sides of the negative electrode sheet 11.

[0034] The number of negative electrode assemblies 10 and positive electrode sheets 20 can be selected according to actual needs, and the stacking method and sequence can also be selected according to actual needs.

[0035] During the stacking process, since the diaphragm 12 has been bonded to the negative electrode sheet 11, when the positive electrode sheet 20 and the negative electrode assembly 10 are stacked, the diaphragm 12 can be prevented from moving or sliding during operation, which can avoid wrinkling and will not affect the position between the positive electrode sheet 20 and the negative electrode sheet 11, which has a good effect on battery performance.

[0036] Furthermore, by pre-bonding the separator 12 to the negative electrode sheet 11 , assembly is facilitated, stacking efficiency is ensured, and battery safety performance is improved.

[0037] The type of the adhesive layer 13 can be selected according to actual needs, and can be set as a PTFE adhesive layer 13, or as a PAA adhesive layer 13, or as a PVDF adhesive layer 13 as described below.

[0038] The technical solution of the present invention forms a negative electrode assembly 10 by bonding the diaphragm 12 and the negative electrode sheet 11 together through the adhesive layer 13, and the diaphragm 12 is set on both sides of the negative electrode sheet 11. The diaphragm 12 is bonded to the negative electrode sheet 11 in advance, which can keep the position of the diaphragm 12 unchanged during the stacking process to avoid wrinkling, and can reduce the adjustment and error of the diaphragm 12 during the assembly process, thereby ensuring that the positive electrode sheet 20 and the negative electrode sheet 11 are not easily misaligned, ensuring the stability and safety of the internal structure of the battery, and improving the battery performance.

[0039] In an embodiment of the present invention, the negative electrode sheet 11 includes a negative electrode body 111 and a negative electrode ear 112, wherein the negative electrode ear 112 is arranged at one end of the negative electrode body 111, and the diaphragm 12 is arranged on the surface of the negative electrode body 111, and the area of the diaphragm 12 is larger than the area of the negative electrode body 111.

[0040] In detail, the negative electrode sheet 11 has a negative electrode ear 112, which is located at the end of the negative electrode body 111, and the separator 12 is mainly adhered to the surface of the negative electrode body 111; at the same time, the area of the separator 12 is set to be larger than the area of the negative electrode body 111. By extending the separator 12 beyond the negative electrode sheet 11, a natural edge sealing layer can be formed when assembling the battery, which helps prevent the electrolyte from leaking from the edge of the battery and reduces the possibility of external contaminants entering the interior of the battery, thereby enhancing the sealing and reliability of the battery.

[0041] During assembly, the slightly larger separator 12 provides greater positioning tolerance, simplifies assembly steps, reduces production defects caused by misalignment, and improves production efficiency and yield. Furthermore, the overhanging portion of the separator 12 helps guide and store more electrolyte, especially at the edge of the battery. This increases the contact area between the electrode and the electrolyte, thereby improving the battery's electrochemical performance.

[0042] In an embodiment of the present invention, each side edge of the separator 12 exceeds the corresponding side edge of the negative electrode body 111 , and the exceeding distance is 1.5 to 2 mm.

[0043] In detail, the diaphragm 12 is bonded to the negative electrode body 111, and each edge of the diaphragm 12 corresponds to each edge of the negative electrode. The edge of each side of the diaphragm 12 is set beyond the edge of the negative electrode body 111, and the exceeding distance can be set to 1.5 to 2 mm, that is, the diaphragm 12 only slightly exceeds the edge of the negative electrode body 111, avoiding unnecessary increase in material costs, and can reduce the difficulty of battery packaging, making the packaging more compact.

[0044] In an embodiment of the present invention, the negative electrode tab 112 is disposed beyond the edge of the separator 12 .

[0045] It is worth noting that Figure 5 and Figure 6 , setting the negative electrode ear 112 beyond the edge of the diaphragm 12 can ensure that the ear is effectively connected to the external conductor, improve production efficiency and assembly accuracy, and reduce the risk of poor welding or damage to the diaphragm 12 due to obstruction by the diaphragm 12; the diaphragm 12 not covering the ear helps heat to be conducted to the outside through the ear, avoids local overheating, and maintains the thermal stability of the battery; therefore, this setting can ensure the reasonable layout of the internal structure of the battery while ensuring the electrical performance and safety of the battery.

[0046] In an embodiment of the present invention, the positive electrode sheet 20 includes a positive electrode body 21 and a positive electrode tab 22 . The positive electrode body 21 is stacked with the negative electrode assembly 10 , and the positive electrode tab 22 is staggered with the negative electrode tab 112 .

[0047] It is worth noting that Figure 1The positive electrode sheet 20 and the negative electrode assembly 10 are stacked, and the positive electrode ear 22 and the negative electrode ear 112 are staggered, which can effectively avoid direct contact between the positive and negative electrodes during the stacking process, thereby preventing short circuit and improving battery safety.

[0048] In an embodiment of the present invention, the adhesive layer 13 is hot-pressed onto the negative electrode sheet 11 and bonded and fixed to the separator 12 ; wherein the hot-pressing temperature is 80-100° C. and the hot-pressing time is 10-60 minutes.

[0049] Specifically, the adhesive layer 13 is connected to the negative electrode sheet 11 by hot pressing. The hot pressing process can make the adhesive layer 13 softer and more fluid when heated, so that it can penetrate into the negative electrode sheet 11. After cooling and solidification, a strong bond is formed, providing stronger bonding strength and durability, and easy operation.

[0050] The specific hot pressing method is: the negative electrode sheet 11 is placed at a certain distance between the two layers of separators 12, with the negative electrode sheets 11 spaced 3 to 4 mm apart, and the separator 12 is provided with a glue layer 13 on one side, and the upper and lower layers of separators 12 both have one side of the glue layer 13 facing the negative electrode sheet 11, and two hot pressing plates are provided outside the two layers of separators 12. The two hot pressing plates are started to make the separator 12 and the negative electrode sheet 11 fit tightly together, wherein the hot pressing temperature is 80 to 100°C, and the hot pressing time is 10 to 60 minutes; under the action of hot pressing, the glue layer 13 of the separator 12 and the negative electrode sheet 11 are heat-fused together, and then the heat-fused separator 12 and the negative electrode sheet 11 are cut to obtain the negative electrode assembly 10.

[0051] In an embodiment of the present invention, the negative electrode assemblies 10 are provided in N+1 groups, the positive electrode sheets 20 are provided in N sheets, and the positive electrode sheets 20 are provided between two adjacent groups of the negative electrode assemblies 10 .

[0052] It is worth noting that the number of negative electrode assemblies 10 is set to be one group more than the positive electrode sheets 20, and the negative electrode assemblies 10 and the positive electrode sheets 20 are stacked in sequence so that the two outermost layers are set as negative electrode sheets 11. After reaching the number of layers required by the process, the stacked electrode body 100 of the battery is formed.

[0053] In an embodiment of the present invention, the diaphragm 12 is a gel diaphragm 12 .

[0054] Specifically, the diaphragm 12 is a gel diaphragm 12 , which has better thermal stability and can reduce the risk of thermal runaway of the battery under overheating conditions; the pore structure of the gel diaphragm 12 is more uniform, and it is easier to connect to the glue layer 13 , and the interaction between the two is relatively stable.

[0055] In the embodiment of the present invention, the material of the adhesive layer 13 is polyvinylidene fluoride.

[0056] It is worth noting that the material of the adhesive layer 13 is polyvinylidene fluoride, also known as PVDF adhesive. The use of PVDF adhesive can provide stable bonding force, ensure close bonding between the diaphragm 12 and the negative electrode sheet 11, and improve the overall structural stability and electrical performance of the battery; and PVDF adhesive has excellent chemical stability, can resist corrosion from the electrolyte, and extend the service life of the battery. PVDF adhesive is resistant to high temperatures and has excellent electrical insulation properties, which can prevent internal short circuits in the battery and improve the safety of the battery.

[0057] A specific method for manufacturing a laminated electrode body 100 is provided: preparing a positive electrode slurry, coating, rolling, and cutting to obtain a positive electrode sheet 20 of a fixed size; similarly, a negative electrode sheet 11 is manufactured in a manner similar to the method for manufacturing the positive electrode sheet 20; a glue layer 13 is bonded to one side of the separator 12; the separator 12 is laid on the lower hot press plate with the glue layer 13 facing upward, and the die-cut negative electrode sheet 11 is laid flat on the separator 12 at a distance of 3 to 4 mm; another layer of separator 12 is laid on the negative electrode sheet 11 with the glue layer 13 facing downward, and the width of the upper and lower layers of separator 12 exceeds the width of the negative electrode sheet 11 1.5~2mm; start the hot pressing plate, and the upper and lower hot pressing plates hot-press the diaphragm 12 and the negative electrode sheet 11 together through the adhesive layer 13, wherein the hot pressing temperature is 80~100℃, and the time is 10~60min; cut the hot-pressed negative electrode sheet 11 according to a fixed size, and the cutting width is that the diaphragm 12 exceeds the edge of the negative electrode sheet 11 by 1.5~2mm to obtain the negative electrode assembly 10; stack the negative electrode assembly 10 and the positive electrode sheet 20 in sequence, with the uppermost and lowermost layers being the negative electrode assembly 10. After reaching the number of layers required by the process, the stacked electrode body 100 of the battery is formed.

[0058] The present invention further provides a battery (not shown), characterized in that it includes the stacked electrode body 100 as described above.

[0059] Specifically, the battery includes the above-mentioned stacked electrode body 100 and a shell, etc. Since the diaphragm 12 can be prevented from wrinkling during the stacking process, the positive electrode sheet 20 and the negative electrode sheet 11 are not easily misaligned, so that the internal structure of the battery is more stable and safer, and the battery performance is relatively excellent.

[0060] The stacked electrode body 100 can be applied to sodium ion batteries or lithium ion batteries.

[0061] The specific structure of the stacked electrode body 100 refers to the above embodiments. Since the battery adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described in detail here.

[0062] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A laminated electrode body that is easy to assemble, characterized in that: The stacked electrode body comprises: A negative electrode assembly, the negative electrode assembly comprising a negative electrode sheet and a separator, the negative electrode sheet comprising a negative electrode body and a negative electrode ear, the negative electrode ear being provided at one end of the negative electrode body, the separator being bonded to surfaces on both sides of the negative electrode sheet by an adhesive layer, the separator being provided on the surface of the negative electrode body, the area of the separator being larger than the area of the negative electrode body, each side edge of the separator extending beyond the corresponding side edge of the negative electrode body by a distance of 1.5 to 2 mm, and the negative electrode ear being provided beyond the edge of the separator; and A positive electrode sheet, the positive electrode sheet and the negative electrode assembly are stacked, the positive electrode sheet includes a positive electrode body and a positive electrode tab, the positive electrode body and the negative electrode assembly are stacked, and the positive electrode tab and the negative electrode tab are staggered; The adhesive layer is hot pressed onto the negative electrode sheet and bonded and fixed to the separator.

2. The easy-to-assemble laminated electrode assembly according to claim 1, wherein: The negative electrode components are arranged in N+1 groups, the positive electrode sheets are arranged in N groups, and the positive electrode sheets are arranged between two adjacent groups of the negative electrode components.

3. The easy-to-assemble laminated electrode assembly according to claim 1, wherein: The diaphragm is a gel diaphragm.

4. The easy-to-assemble laminated electrode assembly according to claim 1, wherein: The material of the adhesive layer is polyvinylidene fluoride.

5. A battery, characterized in that: The invention comprises a stacked electrode body that is easy to assemble according to any one of claims 1 to 4.

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