CN218919009U

CN218919009U - Lithium ion battery

Info

Publication number: CN218919009U
Application number: CN202223091848.9U
Authority: CN
Inventors: 宁锋; 许岩; 彭冲
Original assignee: Zhuhai Cosmx Battery Co Ltd
Current assignee: Zhuhai Cosmx Battery Co Ltd
Priority date: 2022-11-21
Filing date: 2022-11-21
Publication date: 2023-04-25
Anticipated expiration: 2032-11-21

Abstract

The embodiment of the utility model provides a lithium ion battery, which comprises: the electrode comprises a tab, an aluminum plastic film, a winding core, a metal layer and a tab adhesive layer; the electrode lug comprises an anode lug and a cathode lug, the electrode lug adhesive layer comprises an anode lug adhesive and a cathode lug adhesive, the anode lug adhesive is connected with the anode lug, the cathode lug adhesive is connected with the cathode lug, and the anode lug and the cathode lug are respectively connected with the winding core; one end of the metal layer is arranged between the positive electrode lug glue and the aluminum plastic film, and the other end of the metal layer is arranged between the negative electrode lug glue and the aluminum plastic film. According to the utility model, the metal layer is arranged in the connecting layer, so that self-discharge is generated to generate voltage attenuation when the metal layer is melted, and the heat dissipation efficiency of the lithium ion battery is improved.

Description

Lithium ion battery

Technical Field

The utility model relates to the battery industry technology, in particular to a lithium ion battery.

Background

The lithium ion battery has the characteristics of high energy density, high power density, good cycle performance, no memory effect, green environmental protection and the like, so the lithium ion battery is applied to various fields as a power supply. However, as the charging rate increases, the current at the tab overload increases, resulting in higher and higher battery temperatures. At present, heat is generally dissipated at the position of the tab, but the melting point of the tab glue and the material in the aluminum plastic film is higher, so that the heat dissipation is difficult to be dissipated, and the problem of poor heat dissipation efficiency of the lithium ion battery is caused.

Disclosure of Invention

The lithium ion battery provided by the embodiment of the utility model solves the problem of poor heat dissipation efficiency of the lithium ion battery in the prior art.

The embodiment of the utility model provides a lithium ion battery, which comprises: the electrode comprises a tab, an aluminum plastic film, a winding core, a metal layer and a tab adhesive layer;

the electrode lug comprises an anode lug and a cathode lug, the electrode lug adhesive layer comprises an anode lug adhesive and a cathode lug adhesive, the anode lug adhesive is connected with the anode lug, the cathode lug adhesive is connected with the cathode lug, and the anode lug and the cathode lug are respectively connected with the winding core;

one end of the metal layer is arranged between the positive electrode lug glue and the aluminum plastic film, and the other end of the metal layer is arranged between the negative electrode lug glue and the aluminum plastic film.

Optionally, the length of the metal layer is greater than the central distance of the tab, and the central distance of the tab is the distance between the positive tab and the negative tab.

Optionally, the plastic-aluminum membrane includes first face, second face and connection face, first face with the second face is relative, just first face with the second face is passed through the connection face is connected to enclose and close and form the U die cavity, the reel core sets up in the U die cavity.

Optionally, the metal layer includes a first section, a second section and a third section, the second section is disposed between the first section and the third section and is connected to the first section and the third section respectively, the first section and the third section are made of a high thermal conductivity metal material, and the second section is made of a high resistance metal material.

Optionally, the positive electrode tab glue part covers the first section, and the negative electrode tab glue part covers the third section.

Optionally, the plastic-aluminum membrane stacks gradually and sets up including first layer, second layer and third layer, first layer the second layer with the third layer is all different.

Optionally, the metal layer is disposed between the third layer and the tab adhesive layer.

Optionally, the third layer is serrated or wavy;

and/or

The tab adhesive layer is serrated or wavy.

Optionally, the diameter of the metal layer is smaller than a preset value, and the preset value is twice the thickness of the third layer.

Alternatively, the high thermal conductivity metal material includes copper and aluminum, and the high resistance metal material includes manganese, cast iron, and manganese copper alloy.

Drawings

Fig. 1 is a front view of a lithium ion battery according to an embodiment of the present utility model;

fig. 2 is a side view of a lithium ion battery according to an embodiment of the present utility model;

fig. 3 is a schematic diagram of a portion of a lithium ion battery according to the embodiment;

fig. 4 is a second schematic diagram of a portion of the lithium ion battery of the embodiment.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

Before discussing exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although a flowchart depicts steps as a sequential process, many of the steps may be implemented in parallel, concurrently, or with other steps. Furthermore, the order of the steps may be rearranged. The process may be terminated when its operations are completed, but may have additional steps not included in the figures. The processes may correspond to methods, functions, procedures, subroutines, and the like.

Furthermore, the terms "first," "second," and the like, may be used herein to describe various directions, acts, steps, or elements, etc., but these directions, acts, steps, or elements are not limited by these terms. These terms are only used to distinguish one direction, action, step or element from another direction, action, step or element. For example, the first speed difference may be referred to as a second speed difference, and similarly, the second speed difference may be referred to as the first speed difference, without departing from the scope of the present application. Both the first speed difference and the second speed difference are speed differences, but they are not the same speed difference. The terms "first," "second," and the like, are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

Referring to fig. 1 and fig. 2, fig. 1 is a front view of a lithium ion battery provided in an embodiment of the present utility model, and fig. 2 is a side view of a lithium ion battery provided in an embodiment of the present utility model, including: the electrode tab 100, the aluminum plastic film 200, the winding core 400, the metal layer 310 and the electrode tab adhesive layer 320;

the tab 100 comprises a positive tab 110 and a negative tab 120, the tab adhesive layer 320 comprises a positive tab adhesive 321 and a negative tab adhesive 322, the positive tab adhesive 321 is connected with the positive tab 110, the negative tab adhesive 322 is connected with the negative tab 120, and the positive tab 110 and the negative tab 120 are respectively connected with the winding core 400;

one end of the metal layer is arranged between the positive electrode tab glue 321 and the aluminum plastic film 200, and the other end is arranged between the negative electrode tab glue 322 and the aluminum plastic film 200.

The aluminum plastic film 200 includes a first surface 210, a second surface 220, and a connection surface 230, wherein the first surface 210 and the second surface 220 are opposite, and the first surface 210 and the second surface 220 are connected by the connection surface 230 to form a U-shaped cavity;

the winding core 400 is embedded in the U-shaped cavity, the U-shaped cavity comprises an extension part which extends towards one side of the connection surface 230 opposite to the winding core 400, a connection terminal is arranged on the end face of the winding core 400 opposite to one end of the connection surface 230, the tab is electrically connected with the connection terminal, and the tab is connected with the aluminum-plastic film 200 through the connection layer.

In this embodiment, the plastic-aluminum film 200 forms a U-shaped cavity with the first surface 210, the second surface 220 and the connection surface 230, and the winding core 400 is disposed in the U-shaped cavity and contacts the first surface 210 and the second surface 220 of the plastic-aluminum film 200. One end of the tab is connected to the winding core 400 through a connection terminal, and the other end of the tab extends outward beyond the aluminum plastic film 200.

The plastic-aluminum film 200 includes a nylon layer 201, an aluminum layer 202, and a polypropylene layer 203, which are sequentially laminated, and the polypropylene layer 203 is connected to the connection layer. The metal layer 310 is disposed between the polypropylene layer 203 and the tab adhesive.

In this embodiment, referring to fig. 3, fig. 3 is one of partial schematic diagrams of the lithium ion battery of this embodiment, where the plastic-aluminum film 200 includes a first layer, a second layer, and a third layer, and the first layer, the second layer, and the third layer are all different. In this embodiment, the first layer is a nylon layer 201, the second layer is an aluminum layer 202, and the third layer is a polypropylene layer 203, specifically, the aluminum-plastic film 200 includes a nylon layer 201, an aluminum layer 202 and a polypropylene layer 203 which are sequentially stacked, the polypropylene layer 203 is a PP layer, and the longitudinal placement position of the composite metal wire is between the tab adhesive and the PP layer of the aluminum-plastic film 200.

Optionally, the polypropylene layer 203 is serrated or wavy;

and/or

The tab glue is serrated or wavy.

Wherein, the appearance of PP layer and utmost point ear glue of plastic-aluminum membrane 200 is zigzag or wavy, still is favorable to placing of composite wire when improving its cohesiveness, does not increase its top side seal degree of difficulty when increasing the topside and increases composite wire to the effectual area of contact that increases PP layer and utmost point ear glue is difficult for dislocation simultaneously in the encapsulation process, improves the bonding effect of plastic-aluminum membrane 200, reaches the problem that reduces the virtual leak current.

The connection layer is composed of a metal layer 310 and a tab adhesive layer 320, wherein the metal layer 310 is preferably a composite metal wire, and particularly is composed of a plurality of metals. The tab adhesive layer 320 is a tab adhesive, and the tab adhesive is disposed on a portion of the tab and is used for connecting the tab and the first surface 210 and the second surface 220 of the aluminum-plastic film 200. The material of the composite metal wire close to the two ends of the lug is composed of high-heat-conductivity metal, so that the PP layer and the lug glue can be melted in furnace temperature test, wherein the high-heat-conductivity metal can be composed of metal materials such as copper and aluminum. The middle position of the composite metal wire is made of a metal material with high resistance, and the composite metal wire can be self-discharged in the furnace temperature test process, so that the voltage of the battery cell is reduced, and the passing performance of the furnace temperature is improved.

Optionally, the diameter of the metal layer 310 is smaller than a preset value, which is twice the thickness of the polypropylene layer 203.

The longitudinal placement position of the composite metal wire is between the tab glue and the PP layer of the aluminum plastic film 200, and the length of the composite metal wire is slightly larger than the center distance of the tab; the diameter is less than 2 PP layers.

Compared with the traditional battery cell, the utility model adds a composite metal wire at the top of the battery cell, and the composite metal wire is positioned between the positive electrode lug and the negative electrode lug and at the top edge seal of the aluminum plastic film 200. In the furnace temperature test, the high heat conduction metal of the composite metal wire absorbs a large amount of heat and simultaneously transfers the heat to the lug glue, so that the melting rate of the lug glue and the PP layer is accelerated, meanwhile, the PP layer and the lug glue melt, the composite metal wire contacts the positive and negative lugs 120, the high resistance metal in the middle of the composite metal wire can reduce the voltage of the battery cell, and the furnace temperature trafficability is increased. The utility model does not change the original chemical system of the power core, has little influence on the electrochemical performance of lithium ions, simultaneously designs the PP layer of the aluminum plastic film 200 into a saw-tooth shape, designs the PP layer corresponding to the composite metal wire and the tab adhesive layer 320 into an arc shape, reduces the condition of normal temperature virtual sealing and liquid leakage of the aluminum plastic film 200, and simultaneously does not increase the welding difficulty due to the composite metal wire.

In other embodiments, referring to fig. 4, fig. 4 is a second schematic diagram of a portion of the lithium ion battery according to the present embodiment, optionally, the tab includes a positive tab 110 and a negative tab 120, and the length of the metal layer 310 is greater than the tab center distance, and the tab center distance is the distance between the positive tab 110 and the negative tab 120. The tab adhesive layer 320 includes a first tab adhesive layer 321 and a second tab adhesive layer 322, the positive tab 110 is connected with the aluminum plastic film 200 through the first tab adhesive layer 321, and the negative tab 120 is connected with the aluminum plastic film 200 through the second tab adhesive layer 322.

In this embodiment, the tab includes the positive tab 110 and the negative tab 120, where the length of the composite metal wire needs to be greater than the distance between the centers of the tabs, and it needs to be described that the distance between the centers of the tabs refers to the center distance between the positive tab 110 and the negative tab 120, so as to ensure that the composite metal wire can better absorb heat and melt the tab adhesive.

Optionally, the metal layer 310 includes a first section 311, a second section 312, and a third section 313, the second section 312 is disposed between the first section 311 and the third section 313 and is connected to the first section and the third section 313, respectively, the first section 311 and the third section 313 are made of a high thermal conductive metal material, and the second section 312 is made of a high resistance metal material.

The first tab adhesive layer 320 partially covers the first section 311, and the second tab adhesive layer 320 partially covers the third section 313.

In this embodiment, the composite wire is composed of three sections, the first section 311 and the third section 313 are made of the same material, and the second section 312 is disposed between the first section 311 and the third section 313 and connected to the first section 311 and the third section 313, respectively, wherein a portion of the first section is disposed in the first tab adhesive layer 320 and a portion of the third section is disposed in the second tab adhesive layer 320. It should be noted that the PP layer and the tab adhesive disposed on the composite metal wire are set to be serrated or semi-circular, which is beneficial to the placement of the composite metal wire and the encapsulation of the aluminum plastic film 200.

In this embodiment, the composite wire is composed of a high heat conductive metal and a high resistance metal, the high heat conductive metal may be composed of copper, aluminum, and other metals, and the high resistance metal may be composed of one or more of manganese, cast iron, and manganese copper alloy.

Note that the above is only a preferred embodiment of the present utility model and the technical principle applied. It will be understood by those skilled in the art that the present utility model is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the utility model. Therefore, while the utility model has been described in connection with the above embodiments, the utility model is not limited to the embodiments, but may be embodied in many other equivalent forms without departing from the spirit or scope of the utility model, which is set forth in the following claims.

Claims

1. A lithium ion battery, comprising: the electrode comprises a tab, an aluminum plastic film, a winding core, a metal layer and a tab adhesive layer;

2. The lithium ion battery of claim 1, wherein the metal layer has a length greater than a tab center distance, the tab center distance being a distance between the positive tab and the negative tab.

3. The lithium ion battery of claim 2, wherein the aluminum plastic film comprises a first surface, a second surface and a connecting surface, the first surface and the second surface are opposite, the first surface and the second surface are connected through the connecting surface to enclose and form a U-shaped cavity, and the winding core is arranged in the U-shaped cavity.

4. A lithium ion battery according to claim 3 wherein the metal layer comprises a first section, a second section and a third section, the second section being disposed between and connected to the first section and the third section, respectively, the first section and the third section being composed of a high thermal conductivity metal material, and the second section being composed of a high resistance metal material.

5. The lithium ion battery of claim 4, wherein the positive electrode tab paste partially covers the first section and the negative electrode tab paste partially covers the third section.

6. The lithium ion battery of claim 1, wherein the aluminum-plastic film comprises a first layer, a second layer, and a third layer, each of which is different.

7. The lithium ion battery of claim 6, wherein the metal layer is disposed between the third layer and the tab bond layer.

8. The lithium ion battery of claim 7, wherein the third layer is serrated or wavy;

and/or

The tab adhesive layer is serrated or wavy.

9. The lithium ion battery of claim 7, wherein the diameter of the metal layer is less than a preset value that is twice the thickness of the third layer.

10. The lithium ion battery of claim 4, wherein the high thermal conductivity metal material comprises copper and aluminum, and the high resistance metal material comprises manganese, cast iron, and a manganese copper alloy.