Lithium ion battery coil and lithium ion battery
By adopting the negative electrode foil outsourcing structure and all-pole ear welding technology in lithium-ion batteries, the problems of low charging and discharging performance and high temperature rise in existing lithium-ion batteries are solved, and more efficient charging and discharging performance and lower temperature rise are achieved.
Patent Information
- Application Number
- CN202421215076.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-30
- Publication Date
- 2025-04-01
- Estimated Expiration
- 2034-05-30
AI Technical Summary
The current lithium-ion batteries have relatively low rate charging and discharging performance, and the temperature rise is higher during charging and discharging.
The negative electrode foil is outsourcing structure, and is wound on the outside of the diaphragm through the end section of the negative electrode foil and combined with the expansion tape to form a conductive structure, increasing the negative electrode overcurrent capacity and reducing the charge and discharge temperature rise. At the same time, the full-pole ear kneading and full-pole ear collecting plate welding method is adopted to further improve the high-rate charging and discharge performance.
It effectively reduces the temperature rise of lithium-ion batteries during high-rate charging and discharging, and improves the charging and discharging performance and safety performance.
Smart Images
Figure CN222705578U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of lithium ion batteries, and specifically relates to a lithium ion battery coil core and a lithium ion battery. Background Art
[0002] At present, green and efficient secondary batteries are being vigorously developed. As a new type of secondary battery, lithium-ion batteries have the advantages of high energy density and power density, high operating voltage, light weight, small size, long cycle life, good safety, and green environmental protection. They have broad application prospects in portable appliances, power tools, large energy storage, and electric transportation power supply.
[0003] The electrode side of the existing cylindrical lithium-ion battery is usually welded with a single or double pole lug. At the same time, when making the battery cell, a diaphragm is usually used to separate the positive and negative electrodes, and the diaphragm is outsourced and bonded with a finishing glue. However, the rate charge and discharge performance of this lithium-ion battery is relatively low. Utility Model Content
[0004] The technical problem to be solved by the utility model is to provide a lithium ion battery winding core to reduce the temperature rise during charging and discharging and improve the high rate charging and discharging performance in view of the deficiencies of the prior art.
[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is:
[0006] A lithium-ion battery roll core comprises a positive electrode sheet, a negative electrode sheet and a separator, wherein the separator isolates the positive electrode sheet from the negative electrode sheet, and further comprises a glue structure, wherein the glue structure comprises a negative electrode foil tail section and a tail glue, wherein the negative electrode foil tail section exceeds the separator and is wound around the outside of the outermost layer of the separator, wherein the negative electrode foil tail section is not coated with active material, and the tail glue is pasted on the outside of the negative electrode foil tail section.
[0007] Optionally, the finishing adhesive is an expansion tape.
[0008] Optionally, the negative electrode foil tail section is formed by winding the negative electrode foil around the outside of the outermost separator for at least one circle.
[0009] A lithium-ion battery comprises the battery coil core.
[0010] Optionally, the battery roll core is wrapped around a shell, and the shell is a conductive part.
[0011] Optionally, the negative pole ear and the positive pole ear of the battery roll core are formed by flattening through a full-ear flattening technology.
[0012] Optionally, the positive electrode tab is welded to the positive electrode current collecting disk, and the negative electrode tab is welded to the negative electrode current collecting disk.
[0013] Compared with the prior art, the beneficial effects of the utility model are as follows:
[0014] The utility model provides a lithium-ion battery core through the above technical solution, which is wrapped with negative electrode foil and adopts full-ear flattening technology and / or full-ear collector plate welding method to reduce the temperature rise during charging and discharging and improve the high-rate charging and discharging performance.
[0015] In the utility model, the negative electrode foil exceeds the diaphragm and is wound on the outside of the outermost diaphragm to form a negative electrode foil tail section, so that the negative electrode foil outer packaging structure replaces the conventional diaphragm outer packaging structure; the negative electrode foil tail section is not coated with active material, does not participate in electrochemical reaction, and its main function is to conduct electricity; the tail glue is attached to the outside of the negative electrode foil tail section, so that the tail glue automatically releases the restraint after the electrolyte is injected, and the winding core absorbs the electrolyte to expand, so that the negative electrode foil tail section is directly attached to the battery shell, and is in short-circuit contact with the battery shell, which can increase the negative electrode's current capacity, reduce the temperature rise during charging and discharging, and thus improve the high-rate charging and discharging performance.
[0016] The positive and negative pole ears of the utility model are flattened by the full-ear flattening technology, and / or welded by the full-ear collector plate welding method, so as to further improve the high-rate charge and discharge performance and the safety performance of the high-rate charge and discharge of the battery.
[0017] The utility model is verified through a rate charge and discharge temperature rise test experiment that the high rate charge and discharge temperature rise of the lithium ion battery with the structure of the utility model is significantly reduced, and the high rate charge and discharge performance is effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0019] Figure 1 : A schematic diagram of the structure of a battery roll core of the utility model;
[0020] Figure 2 : A schematic diagram of the structure of a battery roll core (wrapped shell) of the utility model;
[0021] Figure 3 : A schematic structural diagram of a lithium-ion battery of the utility model from the first perspective;
[0022] Figure 4: A schematic structural diagram of a lithium-ion battery of the utility model from a second viewing angle;
[0023] Among them, 1. positive electrode sheet; 2. diaphragm; 3. negative electrode foil finishing section; 4. expansion tape; 5. outer shell; 6. battery core; 7. positive electrode current collector; 8. negative electrode current collector. DETAILED DESCRIPTION
[0024] In order to better understand the present invention, the content of the present invention is further clearly described below in conjunction with the embodiments, but the protection content of the present invention is not limited to the following embodiments. In the following description, a large number of specific details are given in order to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details.
[0025] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the illustration to another component, these terms are used in this specification only for convenience, such as according to the orientation of the examples described in the drawings. It is understood that if the device of the illustration is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.
[0026] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used merely as labels and are not intended to limit the quantity of their objects.
[0027] In this application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. "And / or" is just a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the previous and next associated objects are in an "or" relationship.
[0028] For ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. Technologies, methods and devices known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technologies, methods and devices should be considered as part of the authorization specification.
[0029] Unless otherwise specified, all raw materials are from commercially available products and do not contain other unspecified components except inevitable impurities unless otherwise specified.
[0030] Example 1
[0031] like Figure 1 As shown, a lithium-ion battery roll core includes a positive electrode sheet 1, a negative electrode sheet and a separator 2, wherein the separator 2 isolates the positive electrode sheet 1 from the negative electrode sheet, and also includes a glue structure, wherein the glue structure includes a negative electrode foil tail section 3 and a tail glue, wherein the negative electrode foil tail section 3 extends beyond the separator 2 and is wound around the outside of the outermost separator, the negative electrode foil tail section 3 is not coated with active material, and the tail glue is pasted on the outside of the negative electrode foil tail section 3.
[0032] The active materials generally refer to negative electrode active materials such as graphite, MCMB, CMS, etc., as well as auxiliary materials such as solvents for dissolving these negative electrode active materials or adhesives for attaching these negative electrode active materials to negative electrode sheets.
[0033] The end adhesive is an expandable adhesive tape 4 , and there is no special requirement for the width and length of the expandable adhesive tape 4 , and at least the end segment 3 of the negative electrode foil is fixed by adhesive.
[0034] The negative electrode foil tail section 3 is formed by winding the negative electrode foil around the outermost separator for at least one circle. Exemplarily, the negative electrode foil tail section 3 is formed by winding the negative electrode foil around the outermost separator for one circle.
[0035] Example 2
[0036] like Figure 2-4 As shown, a lithium-ion battery includes the battery roll core 6 mentioned above.
[0037] The battery core 6 is wrapped around a shell 5 which is a conductive component.
[0038] The negative and positive tabs of the battery core 6 are formed by flattening the tabs using a full tab flattening technique. The full tab flattening technique may be a technique known in the art.
[0039] The positive electrode ear and the positive electrode current collector plate 7 are welded by a full-ear welding method to form a positive electrode; the negative electrode ear and the negative electrode current collector plate 8 are welded by a full-ear welding method to form a negative electrode.
[0040] In the utility model, the negative electrode foil exceeds the diaphragm 2 and is wound on the outside of the outermost diaphragm to form a negative electrode foil tail section 3, so that the negative electrode foil outer packaging structure replaces the conventional diaphragm outer packaging structure; the negative electrode foil tail section 3 is not coated with active substances and does not participate in electrochemical reactions, and its main function is to conduct electricity; the expansion tape 4 is pasted on the outside of the negative electrode foil tail section 3, so that the expansion tape 4 automatically releases its restraint after the electrolyte is injected, and the battery coil core absorbs the electrolyte to expand, so that the negative electrode foil tail section 3 is directly attached to the battery shell 5, and is in short circuit contact with the battery shell 5, so that the negative electrode foil tail section 3 and the shell 5 together serve as a part of the negative electrode ear, which can increase the negative electrode current capacity, reduce the temperature rise during charging and discharging, and thus improve the high-rate charging and discharging performance.
[0041] The positive and negative pole ears of the utility model are flattened by the full-ear flattening technology, and / or welded by the full-ear collector plate welding method, so as to further improve the high-rate charge and discharge performance and the safety performance of the high-rate charge and discharge of the battery.
[0042] The lithium-ion battery structure of the present invention can be applicable to 21 series cylindrical batteries (such as 21700) or 46 series cylindrical batteries (such as 4695), but is not limited thereto.
[0043] Effect case: The beneficial effects brought about by the utility model are explained below.
[0044] Select two types of commercially available cylindrical lithium-ion batteries (not using the lithium-ion battery structure of the utility model), marked as A1 and A2; make corresponding cylindrical batteries of the same type with the lithium-ion battery structure of the utility model, marked as B1 and B2. Place the four batteries at a constant temperature of 25±3℃, test and record the temperature rise data of different charge and discharge rates. The results are shown in the following table:
[0045]
[0046] It can be seen from the rate charge and discharge temperature rise data that the high rate charge and discharge temperature rise of the utility model lithium ion battery product is significantly reduced, which effectively improves the high rate charge and discharge performance. Therefore, under the same charge and discharge temperature rise conditions, the utility model lithium ion battery can withstand a higher rate of charge and discharge; under the same charge and discharge rate, the temperature rise of the utility model lithium ion battery is lower.
[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the utility model by ordinary technicians in this field should be included in the scope of the claims of the utility model as long as they do not depart from the spirit and scope of the technical solution of the utility model.
Claims
1. A lithium-ion battery roll core, comprising a positive electrode sheet, a negative electrode sheet and a separator, wherein the separator separates the positive electrode sheet from the negative electrode sheet, characterized in that: It also includes a glue-sticking structure, which includes a negative electrode foil tailing section and tailing glue. The negative electrode foil tailing section exceeds the diaphragm and is wound on the outside of the outermost layer of the diaphragm. The negative electrode foil tailing section is not coated with active material, and the tailing glue is attached to the outside of the negative electrode foil tailing section.
2. A lithium-ion battery roll core as claimed in claim 1, characterized in that: The finishing adhesive is expansion tape.
3. A lithium-ion battery roll core as claimed in claim 1, characterized in that: The negative electrode foil tail section is formed by winding the negative electrode foil around the outermost separator for at least one circle.
4. A lithium ion battery, characterized in that: It comprises a lithium-ion battery roll core as described in any one of claims 1 to 3.
5. A lithium ion battery as claimed in claim 4, characterized in that: The battery core is wrapped around a shell, which is a conductive component.
6. A lithium ion battery as claimed in claim 5, characterized in that: The negative pole ears and the positive pole ears of the battery roll core are formed by flattening through the full pole ear flattening technology.
7. A lithium ion battery as claimed in claim 6, characterized in that: The positive electrode ear is welded to the positive electrode current collecting disk, and the negative electrode ear is welded to the negative electrode current collecting disk.