CN113611957A

CN113611957A - Battery cell, battery module and manufacturing method of battery cell

Info

Publication number: CN113611957A
Application number: CN202110885786.XA
Authority: CN
Inventors: 宋鹏辉; 倪尔福; 罗来明; 赵毓毅
Original assignee: Shenzhen Kexin Communication Technology Co Ltd
Current assignee: Shenzhen Kexin Communication Technology Co Ltd
Priority date: 2021-08-03
Filing date: 2021-08-03
Publication date: 2021-11-05
Anticipated expiration: 2041-08-03
Also published as: CN113611957B

Abstract

A battery cell is provided with: a plurality of electrochemical components of the same size and shape connected in parallel; a cell case configured in a box shape with at least one side open for accommodating a plurality of electrochemical components; a mylar film disposed between the plurality of electrochemical components and the cell casing so as to cover the plurality of electrochemical components; the battery cell cover plate seals at least one side opening of the battery cell shell and is provided with a positive terminal and a negative terminal; and at least 1 heat conduction member for heating or dissipating heat from the plurality of electrochemical members, the first heat conduction sheet being in direct contact with the upper surface or the lower surface of the electrochemical members in a manner of being sandwiched between two adjacent electrochemical members, and the at least 1 second heat conduction sheet passing through the slit provided in the mylar film, being in contact with the plurality of side surfaces of the plurality of electrochemical members via the mylar film, and being in direct contact with the cell casing.

Description

Battery cell, battery module and manufacturing method of battery cell

Technical Field

The invention relates to a battery cell, a battery module and a manufacturing method of the battery cell, in particular to a heat dissipation and heating structure of the battery cell.

Background

Lithium ion batteries are the most feasible technical route in the development of energy storage products at present. The lithium ion battery has the advantages of high energy density, small self-discharge, no memory effect, wide working temperature range, quick charge and discharge, long service life, no environmental pollution and the like, and is called as a green battery.

However, lithium ion batteries exist in an operating temperature range. In the case of low ambient temperatures, the lithium ion battery needs to be heated to reach the operating temperature quickly. On the other hand, when the lithium ion battery is charged and discharged, the battery and parts on the passage generate a large amount of heat, if the heat cannot be dissipated in time, the internal temperature of the battery can be continuously increased, and the charging and discharging times and performance of the lithium ion battery can be seriously reduced after the temperature exceeds a threshold value, so that the service life of the lithium ion battery is influenced.

At present, the heating and heat dissipation methods for lithium ion batteries are mainly based on battery module or battery core grades, such as PTC heaters, heating films, heating plates, direct heating by refrigerant, and other heating methods, and natural cooling, liquid cooling, air cooling, phase change cooling, and other heat dissipation methods. For example, patent document 1 discloses a heat dissipation structure of a battery, which includes a battery main body, a mounting frame, and a phase change energy storage plate, wherein a heat dissipation groove is formed in a bottom end surface of the mounting frame, the phase change energy storage plate is fixedly mounted inside the heat dissipation groove, and a heat dissipation fin is arranged on the mounting frame corresponding to the phase change energy storage plate, and a distal end of the heat dissipation fin extends beyond the mounting frame.

Further, patent document 2 discloses a heat dissipation structure for a soft pack lithium ion battery or a square lithium ion battery, in which a heat dissipation plate is provided between cells, and the heat dissipation plate protrudes to the outside of the battery.

However, both of the comparison documents 1 and 2 are based on heating or heat dissipation at the battery pack or cell level, and have a problem of low heating or heat dissipation efficiency. For example, in heat dissipation of the battery, heat is first conducted from the inside of the battery to the case, and then conducted from the case to the outside. Further, the battery does not always have good contact with the case, and the thermal resistance is increased, so that the temperature inside the cell is likely to be excessively high. In particular, the interlayer thermal resistance is large due to the multilayer anisotropy inside the battery, resulting in low heat dissipation efficiency.

As described in patent documents 1 and 2, various proposals have been made in the prior art for dissipating heat transferred to the case after the heat is conducted from the inside of the battery pack or the battery cell to the case. However, when the efficiency of heat transfer from the inside of the battery pack or the battery cell to the casing (in the case of heating, from the casing to the inside of the battery pack or the battery cell) is low, the conventional technology cannot further improve the heat radiation or heating efficiency. With the development of battery technology, high-rate charging has become widespread, and the amount of heat generated during charging and discharging has increased significantly compared to the past, and heat dissipation management has become a problem.

Documents of the prior art

Patent document

Patent document 1: CN212113801U

Patent document 2: CN211088452U

Disclosure of Invention

The invention aims to provide a battery cell, a battery module and a manufacturing method of the battery cell, which can improve the heat dissipation and heating efficiency of a battery.

In order to achieve the above object, the present invention is a battery cell including:

a plurality of electrochemical components of the same size and shape connected in parallel;

a cell case having a box shape with at least one side open, and configured to accommodate the plurality of electrochemical components;

a mylar film disposed between the plurality of electrochemical components and the cell casing so as to cover the plurality of electrochemical components;

the battery cell cover plate is used for sealing at least one side opening of the battery cell shell and is provided with a positive terminal and a negative terminal; and

at least 1 heat conductive member for heating or dissipating heat from the plurality of electrochemical members,

wherein the plurality of electrochemical members are formed in a flat shape, and when a thickness direction of the electrochemical members is defined as a Z-axis direction, the plurality of electrochemical members are arranged in the core housing so as to overlap in the Z-axis direction, each of the plurality of electrochemical members has substantially flat upper and lower surfaces and a plurality of side surfaces between the upper and lower surfaces,

the at least 1 heat conduction component is made of flaky heat conduction materials and comprises a first heat conduction sheet and at least 1 second heat conduction sheet connected with the first heat conduction sheet, a slit for the at least 1 second heat conduction sheet to pass through is arranged on the Mylar film,

the first thermally conductive sheet is in direct contact with the upper surface or the lower surface of the electrochemical member so as to be sandwiched between two adjacent electrochemical members, and the at least 1 second thermally conductive sheet passes through the slit provided in the mylar film, and then is in contact with the plurality of side surfaces of the plurality of electrochemical members via the mylar film, and is in direct contact with the cell casing.

According to the invention, the heat conduction component arranged between the winding cores in the battery core can efficiently conduct the heat in the battery core to the outside, so that the heat dissipation efficiency of the battery core is greatly improved.

Further, preferably, the first thermally conductive sheet and the at least 1 second thermally conductive sheet are integrally formed of the same material,

the first heat conduction sheet is configured in a flat plate shape corresponding to the shapes of the upper surface and the lower surface of the electrochemical member,

the at least 1 second heat-conducting fin is formed by bending towards the Z-axis direction from the edge of the first heat-conducting fin, which corresponds to the edge of the battery cell cover plate, except the edge.

Preferably, the second thermally conductive sheet has a plurality of second thermally conductive sheets, and a part of the plurality of second thermally conductive sheets is bent in an opposite direction to the remaining part in the Z-axis direction.

According to the invention, the plurality of electrochemical components (winding cores or laminated sheets) can be effectively positioned and fixed through the heat conduction component, the displacement of the electrochemical components in the installation process and the use process can be prevented, and the mechanical strength of the battery cell is improved.

Further, it is preferable that a plurality of the second thermally conductive sheets are provided at each edge of the first thermally conductive sheet, and adjacent ones of the plurality of the second thermally conductive sheets provided at the same edge of the first thermally conductive sheet are bent in opposite directions in the Z-axis direction.

According to the present invention, the positioning and fixing effects of the plurality of electrochemical elements (winding cores or stacked sheets) can be further improved, and the electrochemical elements can be more reliably prevented from being displaced during the mounting and use.

Further, it is preferable that the sum of the widths of the plurality of second thermally conductive sheets provided at each edge of the first thermally conductive sheet is smaller than the width of the edge of the first thermally conductive sheet.

According to the present invention, the weight of the heat conductive member can be reduced, which contributes to the weight reduction of the entire battery cell.

Preferably, the electrochemical component is a winding core or a laminate.

Preferably, the first thermally conductive sheet and/or the at least 1 second thermally conductive sheet is configured in a mesh shape or a mesh shape.

Further, it is preferable that, in the case where the electrochemical member is 2, the number of the heat conductive members is 1, and the height of the second heat conductive sheet of the heat conductive member in the Z-axis direction is substantially the same as the thickness of the electrochemical member,

when the number of the electrochemical members is greater than 2, the number of the heat conductive members is less than 1, and the height of the second heat conductive sheet of each of the heat conductive members in the Z-axis direction is less than half the thickness of the electrochemical member.

According to the invention, the heat conduction efficiency of each electrochemical component can be ensured, and the heat conduction effect of the whole battery cell is improved.

Preferably, the at least 1 heat-conducting member has a meandering structure in which 1 heat-conducting member is folded back multiple times, and includes a plurality of first heat-conducting fins, a plurality of connecting portions, and at least 1 second heat-conducting fin, the plurality of first heat-conducting fins and the at least 1 second heat-conducting fin are integrally formed of the same material,

the plurality of first thermally conductive sheets are each configured in a flat plate shape corresponding to the upper surface and the lower surface of the electrochemical member, the number of the plurality of first thermally conductive sheets is 1 less than the number of the plurality of electrochemical members, and a distance between the adjacent first thermally conductive sheets is substantially the same as a thickness of the electrochemical member,

the plurality of connecting portions connect adjacent ones of the first heat-conductive sheets to each other,

the at least 1 second thermally conductive sheet is formed by bending an edge of one first thermally conductive sheet out of two first thermally conductive sheets located on the outermost side in the Z-axis direction, the edge being opposite to an edge corresponding to the cell cover plate, in the Z-axis direction toward the inside of the cell, and the sum of the heights of the at least 1 second thermally conductive sheets in the Z-axis direction does not exceed the sum of the thicknesses of the plurality of electrochemical components.

According to the invention, the number of parts of the heat conducting component can be reduced, so that the structure is simpler and the processing is convenient.

Further, it is preferable that the heat conductive member is made of the same material as the cell casing.

According to the invention, the heat conduction component is made of the same material as the battery cell shell, so that the potential difference between the heat conduction component and the battery cell shell can be effectively avoided, and the whole electrochemical performance of the battery cell is more stable.

Preferably, the heat conductive member is made of a material different from that of the cell casing, and an insulating layer is provided on a side of the heat conductive member that is in contact with the cell casing.

According to the invention, under the condition that the heat conduction component is made of a material different from that of the battery cell shell, the insulating layer is arranged on the side, in contact with the battery cell shell, of the heat conduction component, so that the potential difference between the heat conduction component and the battery cell shell can be effectively avoided, and the whole electrochemical performance of the battery cell is more stable. In addition, the selection range of the heat-conducting component can be expanded by arranging the insulating layer.

Another aspect of the present invention is a battery module including:

the above-described cell; and

and the battery pack shell is used for accommodating a plurality of battery cells.

According to the present invention, a battery module having high heating and heat dissipation efficiency can be obtained.

In addition, another aspect of the present invention is a battery module, a method for manufacturing a battery cell,

the battery cell is provided with:

a plurality of flat electrochemical components having the same size and shape, connected in parallel with each other;

a plurality of the electrochemical components each having substantially planar upper and lower surfaces and a plurality of side surfaces between the upper and lower surfaces,

the manufacturing method of the battery cell comprises the following steps:

overlapping a plurality of said electrochemical components and said at least 1 heat conducting member in a manner that 1 said heat conducting member is sandwiched between adjacent said electrochemical components;

coating a plurality of the electrochemical components and the at least 1 heat-conducting component with a mylar film, and passing the at least 1 second heat-conducting sheet through the slit provided on the mylar film;

bending the at least 1 second thermally conductive sheet in a Z-axis direction so that the at least 1 second thermally conductive sheet is indirectly in contact with the plurality of side surfaces of the electrochemical component via the mylar film, thereby forming a bonded structure of the plurality of battery cells, the at least 1 thermally conductive member, and the mylar film;

encasing the bonding configuration in the cell casing; and

and using the battery cell cover plate to cover one side of the opening of the battery cell shell.

The technical effects are as follows:

according to the invention, the heat of the battery cell, particularly the heat in the battery cell can be efficiently conducted to the outside, and the heating and the heat dissipation of the battery cell can be rapidly realized. In addition, the invention can realize the positioning and fixing of the electrochemical component forming the battery cell in the installation process, can conveniently install the electrochemical component (a winding core or a lamination) into the battery cell shell, and can ensure that the electrochemical component is more stable in the battery cell shell in the use of the battery cell.

Drawings

Fig. 1 is an exploded perspective view of a battery cell according to embodiment 1.

Fig. 2 is a perspective view of a heat conductive member of a battery cell of embodiment 1.

Fig. 3 is a perspective view of a heat conductive member according to a modification of embodiment 1.

Fig. 4 is a perspective view of a heat conductive member according to another modification of embodiment 1.

Fig. 5 is a perspective view of a heat conductive member according to another modification of embodiment 1.

Fig. 6 is a perspective view of a state in which the heat transfer member and the electrochemical component according to embodiment 2 are mounted.

Fig. 7 is a graph of cell operating temperature simulation results of embodiment 1 and the prior art.

Reference numerals:

1 electric core

11 electrochemical component

12 electric core shell

13 mylar film

14 cell cover plate

15. 25, 35, 45 heat conducting member

151. 251, 351, 451A first thermally conductive sheet

152. 252, 352, 452 second thermally conductive sheet

353 connecting part

Detailed Description

Various exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the disclosure, its application, or uses. The present disclosure may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that: unless otherwise indicated, the relative arrangement of components and steps, numerical expressions and numerical values, etc., set forth in these embodiments should be construed as merely illustrative, and not a limitation.

The use of the word "comprising" or "comprises" and the like in this disclosure is intended to mean that the elements listed before the word encompass the elements listed after the word and does not exclude the possibility that other elements may also be encompassed.

All terms (including technical or scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs unless specifically defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

For components, specific models of components, and like parameters, interrelationships between components, and control circuitry not described in detail in this section, can be considered techniques, methods, and apparatus known to those of ordinary skill in the relevant art, but where appropriate, should be considered as part of the specification.

Embodiment mode 1

Embodiment 1 is explained below with reference to the drawings.

First, the basic concept of the cell is explained. The battery cells are basic units constituting a battery module, and one battery module generally includes a plurality of battery cells. The cell includes 1 or more winding cores or a multilayer laminate inside. The cell also includes a cylindrical cell formed by a winding process, depending on the structure. The cell referred to in the present embodiment is a lithium ion cell having a winding core or a lamination as a basic unit. A lithium ion battery is a secondary battery (rechargeable battery) that mainly operates by movement of lithium ions between a positive electrode and a negative electrode. During charging and discharging, Li + is inserted and extracted back and forth between two electrodes: during charging, Li + is extracted from the positive electrode and is inserted into the negative electrode through the electrolyte, and the negative electrode is in a lithium-rich state; the opposite is true during discharge.

As shown in fig. 1, a battery cell 1 of the present invention includes: a plurality of electrochemical components 11, a cell casing 12, a mylar film 13, a cell cover 14, and at least 1 heat conducting member 15.

As described above, in the present embodiment, the plurality of electrochemical elements 11 are wound cores or laminated sheets. Although not shown, the winding core is formed by stacking and winding a negative electrode sheet, a separator, a positive electrode sheet, and a separator, and the stack is formed by stacking a plurality of sheets each including a negative electrode sheet, a separator, a positive electrode sheet, and a separator. The charge and discharge of the battery cell 1 are realized by the ion movement between the positive electrode and the negative electrode. In general, the positive electrode sheet is at zero potential (grounded).

When the electrochemical member 11 is a winding core, the electrochemical member 11 has a flat, substantially rectangular parallelepiped shape, and has substantially flat upper and lower surfaces and a plurality of side surfaces (4 side surfaces in the present embodiment) between the upper and lower surfaces. In practice, two of the four side surfaces of the winding core are slightly rounded because the winding core is manufactured by a winding process. When the thickness direction of the electrochemical member 11 is defined as the Z-axis direction, the plurality of electrochemical members 11 are arranged inside the cell casing 12 so as to overlap in the Z-axis direction.

On the other hand, when the electrochemical device 11 is a laminate, a plurality of sheets including the negative electrode sheet, the separator, the positive electrode sheet, and the separator may be stacked and then bundled in advance to form a laminate. In this case, the electrochemical member 11 refers to a laminated sheet. The laminated core is configured into a flat, substantially rectangular parallelepiped shape, similarly to the winding core described above, and has substantially flat upper and lower surfaces and a plurality of side surfaces (4 side surfaces in the present embodiment) between the upper and lower surfaces. However, unlike the winding process, in the case of the lamination, since the stacking process is employed, four sides are all substantially flat. Similarly to the case of the winding core, when the thickness direction of the electrochemical component 11 is defined as the Z-axis direction, the plurality of electrochemical components 11 (stacked sheets) are arranged inside the cell case 12 so as to be stacked in the Z-axis direction.

In addition, a plurality of sheets including the negative electrode sheet, the separator, the positive electrode sheet, and the separator may not be stacked, and then bundled in advance to form a stacked sheet. In this case, the electrochemical device 11 refers to a stack of a plurality of sheets composed of a negative electrode sheet, a separator, a positive electrode sheet, and a separator.

Regardless of whether the electrochemical member 11 is in the form of a roll or a laminate, portions for forming the positive and negative electrode tabs are reserved in advance during the formation of the electrochemical member 11, specifically, during the cutting of the metal foils forming the positive and negative electrode tabs. In the mounted state of the battery cell 1, a positive electrode tab and a negative electrode tab are connected to a positive electrode terminal and a negative electrode terminal on a cell cover plate 14 described later,

the number of electrochemical components 11 may be designed according to actual circumstances, and in the present embodiment, for the sake of simplicity, the example in which the battery cell 1 includes 2 electrochemical components 11 will be described. However, the number of the electrochemical devices 11 is not limited to 2, and may be more than 2.

The cell casing 12 is formed in a substantially box shape having at least one side opened, and in a typical example, the cell casing 12 is formed in a rectangular parallelepiped shape. The length and width dimensions of the cell casing 12 match those of the electrochemical components 11, and the thickness dimension of the cell casing 12 (i.e., the aforementioned dimension in the Z-axis direction) matches the sum of the thickness dimensions of the plurality of electrochemical components 11 to be housed (i.e., the aforementioned dimension in the Z-axis direction) and the thickness dimension of the heat conductive member 15 described later. At least one side of the cell casing 12 is open for mounting a cell cover 14. Thus, the cell casing 12 has substantially flat upper and lower faces, and 3 side faces between the upper and lower faces. In the present embodiment, only one side of the cell casing 12 is open, that is, the positive electrode terminal and the negative electrode terminal, which will be described later, are exposed on the same side. However, the cell case 12 may have openings on both sides or more, and a positive electrode terminal and a negative electrode terminal, which will be described later, may be exposed on different sides, or openings for other purposes may be provided. In a typical example, the cell casing 12 is an aluminum casing. It should be noted that, in a typical example, the positive electrode tab is at zero potential, and therefore insulation is not generally required between the positive electrode tab and the cell casing 12, but insulation is required between the negative electrode tab and the cell casing 12.

The mylar film 13 is a polyester film for realizing insulation, corrosion prevention, and the like of the electrochemical component 11. In addition, the mylar film 13 covers the plurality of electrochemical members 11 in a state where the plurality of electrochemical members 11 are stacked in the Z-axis direction, thereby bundling the electrochemical members 11. In other words, the plurality of electrochemical components 11 are housed in the cell casing 12 in a state of being covered with the mylar film 13. In addition, a slit through which a second heat conductive sheet 152, which will be described later, of the heat conductive member 15 passes is provided in advance in the mylar film 13.

The cell cover 14 closes one side opening of the cell casing 12. In addition, the cell cover plate 14 is provided with a positive terminal and a negative terminal for connecting a positive tab and a negative tab, and is used for connecting an external lead.

The heat conductive member 15 will be described below with reference to fig. 1 and 2. As shown in fig. 1, the heat conductive member 15 is made of a sheet-like heat conductive material, at least a portion of which is disposed between the adjacent electrochemical members 11 and at least a portion of which is in contact with the cell casing 12. In the prior art, a plurality of electrochemical components 11 are stacked directly and inserted into the cell housing 11 in this state. Therefore, in the related art, heat conduction between the electrochemical members 11 is required in addition to heat conduction inside the electrochemical members 11, and thus heat conduction efficiency is low. In the present invention, the heat conductive member 15 is disposed between the adjacent electrochemical members 11, i.e., the heat conductive member 15 separates the adjacent electrochemical members 11 in the Z-axis direction.

In the present invention, in the case where the electrochemical components 11 are jellyrolls, the number of heat conducting members 15 should be 1 less than the number of electrochemical components 11, since the heat conducting members 15 are directly disposed between the electrochemical components 11. In the case where the electrochemical members 11 are laminated sheets, in the case where the laminated sheets are bundled in advance into a laminated sheet package, the number of the heat conductive members 15 should be 1 less than the number of the electrochemical members 11, as in the case of the winding core. On the other hand, the lamination sheets may not be bundled in advance, but the heat conductive member 15 may be added after a certain number of lamination sheets are stacked during the lamination sheet stacking process, and then the stacking may be continued, thereby completing the addition of the heat conductive member 15 during the lamination sheet stacking process. In this case, the number of the heat conductive members 15 may be appropriately set to a number that meets the heat conductive requirement. In the present embodiment, for the sake of simplicity, the case where the electrochemical element 11 is a winding core and 2 electrochemical elements 11 are provided will be described as an example, and therefore only 1 heat transfer element 15 is provided.

The heat conductive material of the heat conductive member 15 may be selected from metal, nonmetal, and the like. The heat conductive material may be a material different from that of the cell casing 12, and in this case, an insulating layer needs to be disposed at a contact portion of the heat conductive member 15 and the cell casing 12, so as to avoid an influence on performance of the lithium ion battery due to a potential difference generated between the heat conductive member 15 and the cell casing 12. In the case where the heat conductive member 15 is made of the same material as the cell casing 12, the insulating layer may not be provided.

The heat conductive member 15 is described in more detail below with reference to fig. 2. As shown in fig. 2, the heat conductive member 15 includes a first heat conductive sheet 151 and at least 1 second heat conductive sheet 152 perpendicular to the first heat conductive sheet 151. The first thermally conductive sheet 151 and at least 1 second thermally conductive sheet 152 may be made of the same material, or may be made of different materials and integrated by welding, bonding, or the like. In the present embodiment, from the viewpoint of simple manufacturing and ensuring heat transfer efficiency, the first thermally conductive sheet 151 and at least 1 second thermally conductive sheet 152 are preferably integrally formed of the same material. That is, after the shapes of the first thermally conductive sheet 151 and the at least 1 second thermally conductive sheet 152 are previously formed by the same thermally conductive material, the first thermally conductive sheet 151 and the at least 1 second thermally conductive sheet 152 perpendicular to the first thermally conductive sheet 151 are formed by bending.

The first thermally conductive sheet 151 is a substantially flat thermally conductive sheet that is in contact with the upper surface or the lower surface of the electrochemical member 11, and has a shape and a size corresponding to the upper surface or the lower surface of the electrochemical member 11. The second thermally conductive sheet 152 is a substantially flat thermally conductive sheet extending from the edge of the first thermally conductive sheet 151 in the Z-axis direction, and is in contact with the side surface of the electrochemical component 11 and the side surface of the cell casing 12. In the present embodiment, 2 second thermally conductive sheets 152 are provided on each of three edges of the four edges of the first thermally conductive sheet 151. Here, the second thermally conductive sheet 152 is not provided at one edge of the first thermally conductive sheet 151 on the side of the opening of the cell casing 12, that is, on the side where the cell cover 14 is provided. In the case where the cell casing 12 has a plurality of openings, the second thermally conductive sheet 152 is not provided on the opening side. The plurality of second thermally conductive sheets 152 are connected to the first thermally conductive sheet 151, and more preferably, the plurality of second thermally conductive sheets 152 and the first thermally conductive sheet 151 are integrally formed of the same material as described above. Thus, the heat conducted via the first heat conductive sheet 151 can be easily conducted to the second heat conductive sheet 152, forming a direct heat conduction path of the electrochemical member 11 → the first heat conductive sheet 151 → the second heat conductive sheet 152 → the cell casing 12. As described above, by integrally forming the first thermally conductive sheet 151 and at least 1 second thermally conductive sheet 152 using the same material, the thermally conductive member 15 can be easily formed.

As described above, in the present embodiment, 2 second thermally conductive sheets 152 are provided on each of three edges of the four edges of the first thermally conductive sheet 151. Further, 2 second heat conductive sheets 152 provided at each edge of the first heat conductive sheet 151 extend (bend) in opposite directions in the Z-axis direction, respectively. In other words, the second heat conductive sheets 152, which extend (bend) in the Z-axis direction in opposite directions, can simultaneously contact the side surfaces of the two electrochemical members 15 disposed on both sides of the heat conductive member 15. Thus, while the direct heat conduction path of the electrochemical component 11 → the first heat conduction sheet 151 → the second heat conduction sheet 152 → the cell case 12 is formed, the plurality of electrochemical components 11 can be positioned and fixed by the plurality of second heat conduction sheets 152 in contact with the side surfaces of the electrochemical component 11. Moreover, the positioning and fixing actions can be simultaneously performed on the two electrochemical components 15 disposed on both sides of the heat-conducting member 15 by one heat-conducting member 15. This makes it possible to avoid displacement of the electrochemical element 15 when the electrochemical element 11 (winding core or laminate sheet) is mounted in the cell case 12, and to more easily mount the electrochemical element 11 in the cell case. In the use state, the arrangement of the electrochemical component 11 in the cell housing 12 can also be made more stable.

The second heat conduction sheet 152 passes through a slit provided in advance in the mylar film 13, and extends (bends) in the Z-axis direction. Thereby, the second heat conductive sheet 152 covers the mylar film 13 therein, and indirectly contacts the electrochemical device 11 via the mylar film 13.

More specifically, during the installation of the battery cell 1, the heat conducting member 15 is first processed into the shape of the first heat conducting sheet 151 and the second heat conducting sheet 152, and at this time, the second heat conducting sheet 152 is located on the same plane as the first heat conducting sheet 151. Then, the plurality of electrochemical members 11 are covered with the mylar film 13, and the second thermally conductive sheet 152 is passed through the slit provided in the mylar film. After the second heat conductive sheet 152 passes through the slit, the second heat conductive sheet is bent in the Z-axis direction, thereby forming a bonded structure of the electrochemical member 11, the mylar film 13, and the heat conductive member 15.

Further, after the combined configuration of the electrochemical member 11, the mylar film 13, and the heat conductive member 15 is mounted to the inside of the cell casing 12, the second heat conductive sheet 152 of the heat conductive member 15 is in direct contact with the side wall (inner surface) of the cell casing 12.

In the prior art, the heat conduction of the battery cell 1 can only be carried out via the cell casing 12 of the battery cell 1. However, since the electrochemical components 11, particularly the electrochemical components 11 that are located farther from the upper surface and the lower surface of the cell casing 12, have low heat conduction efficiency to the cell casing 12, it is still difficult to efficiently dissipate heat from the inside of the battery cell 1, that is, the plurality of electrochemical components 11, even if various heat dissipation schemes are applied to the cell casing 12. In the invention, by providing the heat conducting member 15, the heat of the electrochemical component 11 can be directly conducted to the first heat conducting fin 151 of the heat conducting member 15 and further conducted to the cell shell 12 through the second heat conducting fin 152, so that the heat inside the cell is directly conducted to the cell shell 12, and the heat conduction efficiency is greatly improved. In the case where the battery cell 1 needs to be heated when first powered on in a cold region or the like, the battery cell 1 can be quickly heated by the heat conductive member 15. Even in the discharged state of the battery module, the heat inside the battery cell 1 (the plurality of electrochemical components) can be efficiently dissipated to the outside through the heat conductive member 15.

Here, in the above-described embodiment, an example is described in which 2 second thermally conductive sheets 152 are provided on each of three edges of the first thermally conductive sheet 151, and the 2 second thermally conductive sheets 152 provided on each edge of the first thermally conductive sheet 151 are extended (bent) in the Z-axis direction in the opposite directions, respectively. However, there is no limitation on the arrangement direction of the second thermally conductive sheet 152. As long as the second thermally conductive sheet 152 is a structure that extends from the edge of the first thermally conductive sheet 151 toward the Z-axis direction and is in direct contact with the side surface of the cell casing 12, the heat of the electrochemical component 11 can be efficiently conducted to the cell casing 12, and positioning and fixing of the electrochemical component 11 can be achieved.

In the above-described embodiment, 2 second thermally conductive sheets 152 are provided at each edge of the first thermally conductive sheet 151, but the number of the second thermally conductive sheets 152 provided at each edge of the first thermally conductive sheet 151 is not limited, and 1 or a plurality thereof may be provided. In the case where a plurality of second thermally conductive sheets 152 are provided at each edge of the first thermally conductive sheet 151, the sum of the widths of the plurality of second thermally conductive sheets 152 provided at the same edge may be equal to the width of the edge to ensure as high a thermal conduction efficiency as possible. On the other hand, the width of the second thermally conductive sheet 152 may be reduced as appropriate from the viewpoint of weight reduction. That is, the sum of the widths of the plurality of second thermally conductive sheets 152 provided on the same edge of the first thermally conductive sheet 151 may be smaller than the width of the edge of the first thermally conductive sheet 151.

In the above-described embodiment, the first thermally conductive sheet 151 and the second thermally conductive sheet 152 are both configured in a sheet shape. However, as a modification of the present embodiment, as shown in fig. 5, the first thermally conductive sheet 151 and the second thermally conductive sheet 152 may be formed in a mesh or mesh shape to further reduce the weight of the entire battery cell 1.

Fig. 3 is a perspective view illustrating a heat conductive member 25 according to a modification of embodiment 1.

From the viewpoint of positioning and fixing the electrochemical component 11 by the heat conductive member, the electrochemical component 11 can be positioned and fixed by extending a part of the plurality of second heat conductive sheets in the Z-axis direction opposite to the remaining part. In this modification, the difference from embodiment 1 described above is that the number of the heat conductive sheets provided on each of the three edges of the four edges of the first heat conductive sheet is different, and the second heat conductive sheets 252 are all extended (bent) in the same direction.

As shown in fig. 3, a heat conductive member 25 is used instead of the heat conductive member 15 in the foregoing embodiment. The heat conductive member 25 includes a first heat conductive sheet 251 and at least 1 second heat conductive sheet 252 perpendicular to the first heat conductive sheet 251. The first thermally conductive sheet 251 and the plurality of second thermally conductive sheets 252 may be formed of the same material, or may be formed of different materials and integrated by welding, bonding, or the like. In the present embodiment, from the viewpoint of simple manufacturing and ensuring heat transfer efficiency, the first thermally conductive sheet 251 and the at least 1 second thermally conductive sheet 252 are preferably integrally formed of the same material. That is, after the first thermally conductive sheet 251 and the at least 1 second thermally conductive sheet 252 are previously formed from the same thermally conductive material, the first thermally conductive sheet 251 and the at least 1 second thermally conductive sheet 252 perpendicular to the first thermally conductive sheet 251 are formed by bending.

As in the previous embodiments, the first thermally conductive sheet 251 is a substantially flat thermally conductive sheet that is in contact with the upper surface or the lower surface of the electrochemical member 11, and has a shape and a size corresponding to the upper surface or the lower surface of the electrochemical member 11. The second thermally conductive sheet 252 is a substantially flat thermally conductive sheet extending from the edge of the first thermally conductive sheet 251 in the Z-axis direction, and is in contact with the side surface of the electrochemical component 11 and the side surface of the cell casing 12. In the present embodiment, 1 second thermally conductive sheet 152 is provided on each of three edges of the four edges of the first thermally conductive sheet 251. Here, the second thermally conductive sheet 152 is not provided at one edge of the first thermally conductive sheet 151 on the side of the opening of the cell casing 12, that is, on the side where the cell cover 14 is provided. The plurality of second thermally conductive sheets 152 are connected to the first thermally conductive sheet 151, and more preferably, the plurality of second thermally conductive sheets 152 and the first thermally conductive sheet 151 are integrally formed of the same material. Thus, the heat conducted via the first heat conductive sheet 151 can be easily conducted to the second heat conductive sheet 152, forming a direct heat conduction path of the electrochemical member 11 → the first heat conductive sheet 151 → the second heat conductive sheet 152 → the cell casing 12. As described above, by integrally forming the first thermally conductive sheet 151 and at least 1 second thermally conductive sheet 152 using the same material, the thermally conductive member 15 can be easily formed.

With such a configuration, while heat conduction is effectively achieved, positioning and fixing of the electrochemical component 11 can also be performed by the plurality of second heat-conductive sheets 152. Since the plurality of second heat conductive sheets 152 are all bent toward the same direction, the electrochemical component 11 wrapped by the second heat conductive sheets can be more stably fixed. This can prevent the electrochemical element 11 (winding core or laminate) from being displaced when it is mounted in the cell case 12. In the use state, the arrangement of the electrochemical component 11 in the cell housing 11 can also be made more stable.

Fig. 4 is a perspective view illustrating a heat conductive member 25 according to another modification of embodiment 1.

As shown in fig. 4, a heat conductive member 35 is used instead of the heat conductive member 15 in the foregoing embodiment. The heat conductive member 35 includes a first heat conductive sheet 351 and at least 1 second heat conductive sheet 352 perpendicular to the first heat conductive sheet 351, and the plurality of second heat conductive sheets 252 are each extended (bent) toward a different direction.

With this configuration, a direct heat conduction path of the electrochemical component 11 → the first heat conduction sheet 351 → the second heat conduction sheet 352 → the cell case 12 can be formed, and the heat of the electrochemical component 11 can be efficiently dissipated to the outside. In addition, compared to the structure in which the plurality of second heat conductive sheets 152 are all bent in the same direction, the electrochemical components 11 on both sides thereof can be stably fixed by one heat conductive member 35.

In addition, in the foregoing embodiment, since 2 electrochemical devices 11 are taken as an example for explanation, 1 heat conduction member 15 simultaneously performs heat conduction and fixation of 2 electrochemical devices 11. In this case, the height of the second heat conductive sheet 152 of the heat conductive member 15 in the Z-axis direction may be substantially the same as the thickness of the electrochemical member 11, i.e., cover the entire height of the side surface of the electrochemical member 11, to ensure as high heat conduction efficiency as possible. When the number of the electrochemical devices 11 is greater than 2, the heat transfer members 15 may be provided in a corresponding number. However, it is worth mentioning that, in the case that the number of the electrochemical components 11 is greater than 2, the height of the second heat conduction sheet 152 of each heat conduction member 15 in the Z-axis direction should be less than half of the thickness of the electrochemical component 11 to avoid interference between the second heat conduction sheets 152 of different heat conduction members 15.

Further, the heat conductive member 15 may also have a plurality of second heat conductive fins 152 extending toward the same side in the Z-axis direction as shown in fig. 3. In this case, while heat conduction is effectively achieved, the electrochemical component 11 can be positioned and fixed by the plurality of second heat conductive sheets 152. Further, in the case where the plurality of second heat-conductive sheets 152 extend toward the same side in the Z-axis direction, only 1 second heat-conductive sheet 152 may be provided instead of the plurality of second heat-conductive sheets 152 at each edge of the first heat-conductive sheet 151.

As shown in fig. 4, the heat-conducting member 15 may be configured such that only 1 second heat-conducting sheet 152 is provided instead of the plurality of second heat-conducting sheets 152 at each edge of the first heat-conducting sheet 151, as in the foregoing embodiment. However, one portion of the plurality of second heat conductive sheets extends (bends) in the opposite direction in the Z-axis direction with respect to the other portion. This makes it possible to more firmly fix the plurality of electrochemical components 11, as compared with a structure in which the plurality of second thermally conductive sheets 152 are all oriented in the same direction. This can prevent the electrochemical element 11 (winding core or laminate) from being displaced when it is mounted in the cell case 12. In the use state, the arrangement of the electrochemical component 11 in the cell housing 11 can also be made more stable.

The inventor of the present invention contrasts the effect difference of the present invention and the prior art through CFD simulation. As shown in fig. 6, the left side of the figure shows the cell operating temperature simulation result of the structure in which the heat conductive member 15 of the present invention is disposed between the electrochemical members 11 of the battery cell 1, and the right side of the figure shows the cell operating temperature simulation result of the prior art in which the heat conductive structure is disposed outside the battery cell. The main difference lies in that, all use the heat conduction structure between two or more electric cores among the prior art, belong to the flat relation between heat conduction structure and the electric core, and both belong to the member of the same level on the physical form. In contrast, in the present invention, the heat conductive member 15 is configured as a lower-stage member of the battery cell 1, and the heat conductive member 15 and the electrochemical member 11 are in a flat-stage relationship in physical form. Compare the outside heat dissipation, heat conduction member 15 sets up and uses the heat conductivility that can greatly promote the battery in electric core 1 inside. Natural heat dissipation is the environmental condition with the weakest heat dissipation capability (environmental conditions are classified, natural heat dissipation is less than liquid cooling heat dissipation and is less than direct cooling heat dissipation).

The simulation means is used for simulating the application of the heat conduction structure to the inside and outside of the battery in a natural heat dissipation environment, and the working condition of the battery is discharging for 1800s at normal temperature 2C (100A). The results are shown on the right side of fig. 6: the maximum cell temperature was 64.8 ℃. On the other hand, the heat conductive member 15 is applied inside the battery cell 1, as shown on the left side of fig. 6, with the maximum battery temperature being 48.3 ℃. Namely, the heat conducting member 15 is arranged inside the battery core 1, so that the battery temperature can be reduced by 16.5 ℃ under the same working condition, and the heat dissipation effect is remarkable.

Further, it is worth noting that in the prior art simulation on the right side of fig. 6, the highest temperature (64.8 ℃) does not appear in the picture because the highest temperature appears inside the cell. On the other hand, in the simulation of the present invention on the left side of fig. 6, the highest temperature (48.3 ℃) appears on the cell casing. It can be seen that, by adopting the invention, the temperature of the battery can be effectively reduced (64.8 ℃ → 48.3 ℃), and the highest temperature point of the battery core 1 can be transferred to the battery core shell 12 by the operation of the heat conducting member 15, so that the heat dissipation effect is remarkable. The heat conductive member 15 has the same remarkable effect when used to heat the battery cell 1. After the environmental heat conduction condition is changed into liquid cooling or direct cooling, the heat conduction effect caused by the heat conduction member 15 arranged inside the battery cell 1 is more remarkable than that under the natural heat dissipation working condition.

Embodiment mode 2

Embodiment 2 will be described below with reference to fig. 7. In embodiment 1, each heat transfer member 15 disposed between adjacent electrochemical members 11 is a single structure, and each heat transfer member 15 conducts heat of the electrochemical members 11 on both sides. In the present embodiment, the heat conductive member 45 is formed as an integral structure. That is, the heat conductive member 45 has a meandering structure in which the heat conductive member is folded back a plurality of times, and the plurality of first heat conductive sheets 451 are connected by the connection portion 453. Thereby, heat conduction of the plurality of electrochemical members 11 can be achieved by one heat conductive member 45. Further, the second thermally conductive sheet 452 is provided at one edge of two first thermally conductive sheets 451 that are positioned outermost in the Z-axis direction among the plurality of first thermally conductive sheets 451, specifically, at an edge of a side where the cell cover 14 is not provided. The second thermally conductive sheet 452 may be provided on both of the outermost two first thermally conductive sheets 451, or the second thermally conductive sheet 452 may be provided only on 1 of the second thermally conductive sheets 452.

The heat conductive member 45 of the present embodiment also enables the electrochemical member 11 to be positioned and fixed while efficiently achieving heat conduction from the electrochemical member 11 to the cell case 12.

It should be understood that the above-mentioned embodiments are only for explaining the present invention, and the protection scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the technical scope of the present invention and the technical solutions and inventive concepts thereof equivalent or changed within the technical scope of the present invention/utility model disclosed by the present invention.

Claims

1. A battery cell is provided with:

2. The electrical core of claim 1, wherein the cell is,

the first thermally conductive sheet and the at least 1 second thermally conductive sheet are integrally formed of the same material,

3. The electrical core of claim 2,

the second heat-conductive sheet has a plurality of second heat-conductive sheets, and a part of the plurality of second heat-conductive sheets is bent in an opposite direction in the Z-axis direction with respect to the remaining part.

4. The electrical core of claim 3,

a plurality of the second thermally conductive sheets are provided at each edge of the first thermally conductive sheet, and adjacent ones of the plurality of second thermally conductive sheets provided at the same edge of the first thermally conductive sheet are bent in opposite directions in the Z-axis direction.

5. The electrical core of claim 4,

the sum of the widths of the plurality of second thermally conductive sheets provided at each edge of the first thermally conductive sheet is smaller than the width of the edge of the first thermally conductive sheet.

6. The cell of any of claims 1 to 6,

the electrochemical component is a jellyroll or a laminate.

7. The cell of any of claims 1 to 6,

the first heat-conducting sheet and/or the at least 1 second heat-conducting sheet are configured to be in a wire mesh shape or a mesh shape.

8. The cell of any of claims 2 to 6,

when the number of the electrochemical member is 2, the number of the heat conductive members is 1, and the height of the second heat conductive sheet of the heat conductive member in the Z-axis direction is substantially the same as the thickness of the electrochemical member,

9. The electrical core of claim 1, wherein the cell is,

the at least 1 heat conduction member is 1 meandering structure which is folded back for multiple times, and comprises a plurality of first heat conduction sheets, a plurality of connection parts, and at least 1 second heat conduction sheet, the plurality of first heat conduction sheets and the at least 1 second heat conduction sheet are integrally formed by the same material,

10. The cell of any of claims 1-6, 9,

the heat conductive member is made of the same material as the cell casing.

11. The cell of any of claims 1-6, 9,

the heat conductive member is composed of a material different from the cell casing,

an insulating layer is arranged on one side of the heat conducting component, which is in contact with the battery cell shell.

12. A battery module is characterized by comprising:

a plurality of the cells of any one of claims 1-11; and

13. A method for manufacturing a battery cell is characterized in that,

the battery cell is provided with:

the manufacturing method of the battery cell comprises the following steps:

encasing the bonding configuration in the cell casing; and