CN211320192U

CN211320192U - Battery module

Info

Publication number: CN211320192U
Application number: CN202020380922.0U
Authority: CN
Inventors: 尚德华; 杨泽乾
Original assignee: Shanghai Yuyuan Power Technology Co ltd
Current assignee: Aopu Shanghai New Energy Co Ltd
Priority date: 2020-03-24
Filing date: 2020-03-24
Publication date: 2020-08-21
Anticipated expiration: 2030-03-24

Abstract

Disclosed is a battery module. The utility model discloses an in the embodiment, the battery module can include: the device comprises two or more batteries, a heat-conducting silica gel sheet, an optical fiber monitoring part and a heat-conducting silica gel sheet, wherein the heat-conducting silica gel sheet is arranged between the two batteries, and two side surfaces of the heat-conducting silica gel sheet are respectively contacted with the surfaces of the two batteries; temperature monitoring portion includes: the optical fiber sensor, the optical fiber and the fiber grating demodulator; the optical fiber sensor and the optical fiber are fixed inside the heat-conducting silica gel sheet, one end of the optical fiber is connected with the optical fiber sensor, and the other end of the optical fiber extends out of the top end of the heat-conducting silica gel sheet and is connected with the fiber bragg grating demodulator. The utility model discloses not only can additionally not increase the volume of group battery, moreover can guarantee the real temperature of battery in the heat dissipation effect accurate monitoring battery module to show and reduce the risk that misjudgments and reaction are untimely, effectively prevent the emergence of thermal runaway.

Description

Battery module

Technical Field

The utility model relates to a lithium cell technical field especially relates to a battery module and assembly method thereof.

Background

At present, the lithium ion battery is widely applied to various energy storage fields due to the advantages of high energy density, long service life, environmental protection and the like. And the ever-increasing energy density of batteries puts higher demands on the safety of the batteries. However, the lithium battery pack generates a large amount of heat during operation, and the amount of heat generated by each battery is often different, so that the heat generated by the battery needs to be diffused in time, otherwise, the service life of the battery is rapidly reduced, and even explosion or combustion is caused. And, the temperature of the battery needs to be kept consistent, otherwise the consistency error of the battery will be gradually increased after the battery is operated for a period of time, which results in the reduction of the service life of the battery pack, namely the short plate effect.

At present in lithium battery module or lithium battery package (pack) field, heat conduction silica gel very wide application in the heat dissipation management of lithium cell group, can in time pass away the used heat that lithium cell group produced through heat conduction silica gel, the uniformity of guarantee group battery temperature, when the group battery received external force to strike, can also play shock-proof absorbing effect simultaneously. When the temperature of the battery pack is monitored, temperature measuring elements such as thermistors are often adopted, due to the limitation of the space of the battery pack, gaps among batteries are limited, the heat-conducting silica gel sheet is filled, and the temperature measuring elements are difficult to arrange on the surface of the battery, so that the temperature measuring probe is often bonded on a lug connecting sheet of the battery or placed at a certain fixed position needing temperature measurement to detect the temperature of the battery pack, and the temperature measurement of the battery pack is inaccurate.

Disclosure of Invention

In order to solve the technical problems and other partial technical problems partially or completely, embodiments of the present invention provide a battery module and an assembling method thereof.

According to the utility model discloses an aspect provides a battery module, include:

two or more batteries;

the heat-conducting silica gel sheet is arranged between the two batteries, and two side surfaces of the heat-conducting silica gel sheet are respectively contacted with the surfaces of the two batteries;

temperature monitoring portion includes: the optical fiber sensor, the optical fiber and the fiber grating demodulator;

the optical fiber sensor and the optical fiber are fixed inside the heat-conducting silica gel sheet, one end of the optical fiber is connected with the optical fiber sensor, and the other end of the optical fiber extends out of the top end of the heat-conducting silica gel sheet and is connected with the fiber bragg grating demodulator.

The embodiment of the utility model provides a, the optical fiber sensor integration that will be used to detect battery temperature is inside heat conduction silica gel, utilizes heat conduction silica gel piece to monitor the temperature of battery through optical fiber sensor when carrying out the heat dissipation to the battery module, not only can additionally not increase the volume of group battery, can accurately monitor the true temperature of battery in the battery module in addition when guaranteeing the radiating effect to show and reduce the risk that misjudgments and reaction are untimely, effectively prevent the emergence of thermal runaway.

Drawings

Fig. 1 is an illustration of a partial structure of a battery module according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view of a heat-conducting silicone sheet of a battery module according to an embodiment of the present invention.

Fig. 3 is an illustration diagram of the embodiment of the present invention in which the optical fiber sensor and the optical fiber are disposed on the heat conductive silicone sheet.

Fig. 4 is a schematic view illustrating an assembly process of the battery module according to an embodiment of the present invention.

Description of reference numerals:

10. a battery module; 11. a battery; 12. a heat-conducting silica gel sheet; 13. an optical fiber sensor; 14. an optical fiber; 141. A fiber core; 142. a single layer of non-stick coating.

Detailed Description

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of conflict, the various embodiments and features thereof may be arbitrarily combined with each other.

In the field of lithium ion battery modules, in order to improve energy density, battery materials with high specific energy need to be used, and the battery modules are designed to be light and compact, so that the battery modules are required to have high heat dissipation performance and heat transfer performance, and a temperature measurement system with high measurement accuracy, short response time and high anti-interference stability is provided.

As described above, in the related art, the heat dissipation performance and temperature uniformity of the battery pack are improved by simply adding various types of heat conductive films and heat dissipation devices, and the temperature of the battery pack needs to be monitored by a thermocouple or the like. However, because the volume of the battery pack is limited and the gaps between the batteries are limited, after the gaps between the batteries are filled with the heat-conducting silicon sheets, the positions of elements such as thermocouples are generally positioned on the lug connecting sheets, and because the temperature of the lug connecting sheets cannot accurately reflect the temperature of the batteries, the temperature measurement is often inaccurate by using the method, and the risks of misjudgment and untimely reaction exist. In other words, there is a conflict between battery pack volume and temperature measurement accuracy.

In order to solve the technical problem, the utility model provides a basic concept provides a battery module and assembly method thereof, among this battery module, the optical fiber sensor that can be used to detect battery temperature is integrated inside heat conduction silica gel, need not to increase the space between the battery when can accurate measurement battery temperature, do not additionally increase the volume of group battery, heat conduction silica gel piece still can be full of hugs closely the battery surface between the battery, do not influence the radiating effect, also to the energy density of battery module few no influence. In addition, the optical fiber has excellent electromagnetic and atomic radiation resistance, chemical properties of water resistance, high temperature resistance and corrosion resistance, and light and soft mechanical properties, and is very suitable for temperature monitoring of a lithium ion module or assembly, so that the true temperature of each battery in the battery module can be accurately monitored while the heat dissipation performance of the battery module is guaranteed, the risks of misjudgment and untimely reaction can be remarkably reduced, and the occurrence of thermal runaway can be effectively prevented.

The following describes an exemplary implementation of the battery module and the assembling method thereof in the embodiment of the present invention in detail.

Fig. 1 shows the embodiment of the present invention in which a partial structure of the battery module 10 is shown, and fig. 2 shows the embodiment of the present invention in which a heat-conducting silica gel sheet of the battery module 10 is shown. As shown in fig. 1, the battery module 10 may include: two or more than two batteries 11, heat conduction silica gel piece 12 and temperature monitoring portion, temperature monitoring portion can include: a fiber sensor 13, a fiber 14 and a fiber grating demodulator (not shown in the figure).

Fig. 3 shows an exemplary view in which the optical fiber sensor 13 and the optical fiber 14 are disposed on the thermally conductive silicone sheet 12. The optical fiber sensor 13 and the optical fiber 14 are fixed inside the heat-conducting silica gel sheet 12, one end of the optical fiber 14 is connected with the optical fiber sensor 13, and the other end extends out from the top end of the heat-conducting silica gel sheet 12 and is connected with a fiber grating demodulator (not shown in the figure).

The embodiment of the utility model provides an in, heat conduction silica gel piece 12 can adopt raw and other materials such as heat conduction filler, fire retardant, pigment, cross-linking agent, catalyst to make. As shown in fig. 1, in order to improve the heat dissipation performance and the temperature uniformity of the battery module, the heat conductive silicone sheet 12 may be tightly attached between the two batteries 11 without a gap. In some examples, the thickness of the thermally conductive silicone sheet 12 matches the size of the gap between adjacent cells 11 in the battery module. For example, when the gap between the adjacent batteries 11 in the battery module is 1-2 mm, the thickness of the heat-conducting silicone sheet 12 can be 1-2 mm. For example, the thickness of the heat conductive silicone sheet 12 is preferably about 1 mm. In addition, the size of the thermally conductive silicone sheet 12 may be matched to the size of the surface of the battery 11. For example, the size of the heat conductive silicone sheet 12 may be slightly smaller than the size of the surface (i.e., the heat generating surface) of the battery 11.

In the embodiment of the present invention, the optical fiber sensor 13 can be fixed inside the heat-conducting silicone sheet 12 through various possible modes. In some examples, the thermal silicone sheet 12 may have a hole at a predetermined position, and the optical fiber sensor is fixed in the hole. For the convenience of forming, the hole may be a regular hole, and preferably, the size and shape of the hole may be adapted to the size and shape of the optical fiber sensor 13. For example, the optical fiber sensor 14 is generally quadrilateral, the hole may be quadrilateral, and the inner cavity of the hole can just accommodate the optical fiber sensor 13. In some examples, to avoid increasing the thickness, the thickness of the optical fiber sensor 13 may be slightly smaller than the thickness of the heat conductive silicone rubber sheet 12, and the optical fiber sensor 13 may be embedded in the hole of the heat conductive silicone rubber sheet 12 by means of embedding or buckling, so that the optical fiber sensor 13 not only can contact with the surfaces of the batteries 11 on both sides of the heat conductive silicone rubber sheet 12 to monitor the surface-related optical signals, but also can be embedded in the hole without increasing the thickness of the heat conductive silicone rubber sheet 12.

In practical applications, when the thermal silicone sheet 12 is located between two batteries 11, the predetermined position on which the optical fiber sensor 13 is fixed can be just in contact with the surface heating area of the batteries 11. Taking fig. 2 and 3 as an example, the predetermined position may be a central position of the surface of the thermally conductive silicone sheet 12. Of course, fig. 2 and fig. 3 are only examples, and in practical applications, the predetermined position may also be any other position on the surface of the thermal-conductive silicone sheet 12, which is not limited by the embodiment of the present invention.

In the embodiment of the present invention, the optical fiber 14 can be disposed in the heat-conducting silicone sheet 12 in various applicable manners. Taking fig. 2 and 3 as an example, a hollow tube may be disposed in the heat-conducting silica gel sheet 12, one end of the optical fiber 14 penetrates into the hollow tube through an opening of the hollow tube located at the top end of the heat-conducting silica gel sheet 12 and is connected to the optical fiber sensor 13, and the other end of the optical fiber 14 is located outside the heat-conducting silica gel sheet 12 and is connected to a fiber grating demodulator (not shown in the figure). The optical fiber 14 is arranged inside the heat-conducting silica gel sheet 12 in a hollow pipeline mode, the optical fiber 14 can be conveniently embedded into the heat-conducting silica gel sheet 12, the optical fiber 14 can be protected through the heat-conducting silica gel sheet 12, the optical fiber 14 is prevented from being broken, the thickness of the heat-conducting silica gel sheet 12 cannot be increased, the heat-conducting silica gel sheet 12 containing the optical fiber 14 is accommodated without increasing the gap between the batteries 11, therefore, the accuracy of monitoring the surface temperature of the batteries can be ensured, and meanwhile, the extra increase of the volume of the battery module 10 can be avoided.

In the embodiment of the present invention, since the optical fiber 14 is disposed inside the heat conductive silicone sheet 12, the optical fiber 14 can be protected by the heat conductive silicone sheet 12, so the optical fiber 14 does not need to adopt a multilayer protection like a common optical fiber, and only one layer of non-stick coating (e.g., Polytetrafluoroethylene (PTFE)) is added as a protection layer of the optical fiber, that is, as shown in fig. 3, the optical fiber 14 of the embodiment of the present invention can include a bare fiber core 141 and a single-layer non-stick coating 142 coated on the outer surface thereof, the optical fiber 14 adopting the single-layer protection layer also helps to reduce the diameter of the optical fiber 14, thereby avoiding increasing the thickness of the heat conductive silicone sheet 12 due to the built-in optical fiber 14.

The embodiment of the utility model provides an in, the fiber grating demodulator can set up on the shell of battery module 10, is convenient for external battery management system. The fiber grating demodulator can be used for determining the surface temperature of the battery 11 according to the reflection center wavelength transmitted by the optical fiber 14 in real time and transmitting the real-time calculated temperature value to an external battery management system, thereby realizing the real-time monitoring of the surface temperature of the battery.

In practical application, when the battery module 10 works, the optical fiber 14 is connected to the fiber bragg grating demodulator, that is, the reflection center wavelength of each fiber bragg grating is measured, then the temperature value of each measurement point is calculated according to the preset relation between the reflection center wavelength and the temperature, and the temperature value is transmitted to the battery management system, so that the temperature on the surface of the battery can be monitored in real time.

For example, the predetermined relationship between the reflection center wavelength and the temperature may be as shown in the following formula (1), in which the coefficient α and the coefficient β can be statistically analyzed through experiments.

λ＝α+βt (1)

Where λ represents the currently measured reflection center wavelength, and t represents the temperature at the location where the optical fiber sensor 13 is located, that is, t is the temperature of the battery surface.

Fig. 4 shows an exemplary assembly process of the battery module 10 in the embodiment of the present invention. As shown in fig. 4, the assembly process of the battery module 10 may include the steps of:

step S410, a heat-conducting silicone rubber sheet 12 with a predetermined thickness is obtained.

In some examples, this step may include: and preparing a heat-conducting silica gel sheet, and cutting the heat-conducting silica gel sheet into a size matched with the side surface of the battery. Specifically, the raw materials such as organic silicon, heat-conducting filler, flame retardant, pigment, crosslinking agent and catalyst can be first prepared into a heat-conducting silica gel sheet with the thickness of 1mm through the processes of heating to remove water, stirring and mixing, calendering and vulcanizing, then the prepared heat-conducting silica gel sheet is trimmed and cut into the required size according to the design requirements of the battery pack, and the size of the cut heat-conducting silica gel sheet can be slightly smaller than the maximum surface of the battery.

Step S420, punching holes on the heat-conducting silica gel sheet 12;

and punching holes matched with the size of the optical fiber sensor on the heat-conducting silica gel sheet.

This step may be performed, for example, by an automated punching device or an automated punching tool. Firstly, after fixing the heat-conducting silica gel sheet by using a fixture, punching holes with regular shapes at corresponding temperature testing positions (i.e. the predetermined positions), and the details of the holes can refer to the above description and are not repeated.

In step S430, a hollow pipe is drilled into the heat-conductive silicone sheet 12.

For example, a hollow tube can be drilled on one side of the heat-conducting silicone sheet by using a stainless steel hollow tube with a diameter not exceeding the thickness of the heat-conducting silicone sheet (for example, the diameter is 0.75 times of the thickness of the heat-conducting silicone sheet), one end of the hollow tube can be communicated with the hole, and the other end of the hollow tube is provided with an opening at the top end of the heat-conducting silicone sheet.

In practical applications, this step can be performed by using an automated device.

Step S440, fixing the optical fiber sensor 13 on the hole of the heat-conducting silica gel sheet 12, and inserting one end of the optical fiber 14 into the hollow pipe through the opening of the hollow pipe at the top end of the heat-conducting silica gel sheet 12 and connecting the optical fiber sensor 13.

Specifically, the bare fiber core is coated with a PTFE layer and then passes through the hollow tube punched in step S430 to the other end of the hole in the heat-conducting silicone sheet 12, and the optical fiber 14 is connected to the optical fiber sensor 13 at one end of the hole in the heat-conducting silicone sheet 12, so that the thicknesses of the optical fiber 14, the end of the optical fiber connected to the optical fiber sensor 13, the connection between the optical fiber and the optical fiber sensor, and the optical fiber sensor are all equal to or slightly less than the thickness of the heat-conducting silicone sheet, thereby preventing the heat-conducting silicone sheet 12 from increasing in thickness, increasing the space occupied between the batteries, and further affecting the volume of the battery module.

Step S450, the heat conductive silicone sheet 12 is placed between the two batteries 11, and two side surfaces of the heat conductive silicone sheet 12 are respectively in contact with the surfaces of the two batteries 11.

Specifically, the heat-conducting silicone sheet 12 containing the optical fiber 14 and the optical fiber sensor 13 is placed between two batteries 11 when the module is manufactured, the batteries 11, the heat-conducting silicone sheet 12 and the batteries 11 are tightly attached without gaps, and the optical fiber sensor 13 can be adhered to the surface of one of the batteries.

Step S460, the other end of the optical fiber 14 extending from the top of the thermal conductive silicone rubber sheet 12 is connected to the fiber grating demodulator.

Specifically, the other end of the optical fiber 14 passes through the upper portion of the thermal silicone sheet 12, and is bundled with a voltage measuring harness or the like, and is connected to an optical fiber modem placed outside the battery module 10.

In some examples, the method of assembling the battery module 10 may further include: before the optical fiber is connected to the fiber bragg grating demodulator, the fiber bragg grating demodulator can be fixed on the shell of the battery module.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered by the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A battery module, comprising:

two or more batteries;

2. The battery module according to claim 1, wherein the heat conductive silicone sheet is tightly attached between the two batteries without a gap.

3. The battery module according to claim 1 or 2, wherein the thickness of the heat-conducting silicone sheet is matched with the size of a gap between adjacent batteries in the battery module.

4. The battery module according to claim 3, wherein the thickness of the heat conductive silicone sheet is 1 mm.

5. The battery module according to claim 1 or 4, wherein the size of the heat conductive silicone sheet matches the size of the battery surface.

6. The battery module according to claim 1, wherein a hole is formed in a predetermined position of the heat-conducting silicone sheet, and the optical fiber sensor is fixed in the hole.

7. The battery module according to claim 1 or 6, wherein a hollow tube is disposed inside the heat-conducting silicone sheet, one end of the optical fiber penetrates into the hollow tube through an opening of the hollow tube located at the top end of the heat-conducting silicone sheet and is connected to the optical fiber sensor, and the other end of the optical fiber is located outside the heat-conducting silicone sheet and is connected to the fiber grating demodulator.

8. The battery module according to claim 1, wherein the optical fiber comprises a bare fiber core and a single-layer non-stick coating coated on an outer surface thereof.

9. The battery module of claim 1, wherein the fiber grating demodulator is disposed outside the battery module housing.