CN219349082U - Battery expansion force testing device - Google Patents

Abstract

The application relates to the technical field of batteries, in particular to a battery expansion force testing device. The battery expansion force testing device is used for detecting the expansion force in the battery, the testing device comprises a film pressure sensor, monitoring equipment and a data wire, the battery comprises a shell and a core body, a wire through hole is formed in the shell, and the core body is arranged in the shell; the film pressure sensor is arranged in the core body and/or between the core body and the shell; the monitoring equipment is used for monitoring pressure information of the film pressure sensor; the data line runs through the casing through the line hole, and the one end and the film pressure sensor of data line are connected, and the other end is connected with monitoring facilities, and the line hole passes through the sealing member and seals. The film pressure sensor is arranged in different positions inside the shell of the battery, and performs data interaction with the monitoring device through the data wire, so that pressure information of different positions inside the shell can be directly obtained, and the interference of the thickness and the hardness of the battery shell on the expansion force test is eliminated.

Description

Battery expansion force testing device

Technical Field

The application relates to the technical field of batteries, in particular to a battery expansion force testing device.

Background

In the long-term use of the lithium ion battery, the lithium ion battery can expand, and risks such as explosion can occur when the expansion reaches a certain degree. Particularly, as a power source of the electric automobile, the battery runs in a safe and reliable state, and is very important for the normal use of the electric automobile. Specifically, the volume expansion of the unit cell is inconsistent due to the intercalation and deintercalation of lithium ions in the anode material and the cathode material, and the working process of the lithium ion battery is accompanied with the volume change of the electrode material and is represented by the thickness change of the pole piece. The battery gradually ages during recycling, and gas is generated to cause the battery to expand. Variations in thickness and expansion forces can adversely affect the performance (capacity, cycle life, etc.) of the lithium ion battery and the battery module. Therefore, for battery safety, reliability and life considerations, it is necessary to test the battery expansion force during battery development.

The conventional testing method mainly places the pressure sensor outside the battery, and the thickness and hardness of the battery case can interfere with the testing.

Disclosure of Invention

The present utility model aims to solve at least one of the technical problems existing in the prior art. Therefore, the utility model provides a battery expansion force testing device, which is used for eliminating the interference of the thickness and the hardness of a shell on the testing in the process of detecting the battery expansion force.

The application provides a battery expansion force testing arrangement, it is used for detecting the inside expansion force of battery, the battery includes casing and core, the wire hole has been seted up on the casing, the core sets up in the casing, this battery expansion force testing arrangement includes:

the film pressure sensor is used for being arranged in the core body and/or between the core body and the shell;

the monitoring equipment is used for monitoring pressure information of the film pressure sensor;

and the data wire penetrates through the shell through the wire through hole, one end of the data wire is connected with the film pressure sensor, and the other end of the data wire is connected with the monitoring equipment.

According to the battery expansion force testing device, the film pressure sensor is arranged in different positions inside the shell of the battery, and performs data interaction with the external monitoring device through the data wire, so that pressure information of different positions inside the battery shell can be directly obtained, and the interference of the thickness and hardness of the battery shell to the expansion force testing is discharged.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the utility model and together with the description, serve to explain the principles of the utility model.

In order to more clearly illustrate the embodiments of the utility model or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, and it will be obvious to a person skilled in the art that other drawings can be obtained from these drawings without inventive effort.

Fig. 1 is a schematic perspective view showing a battery expansion force testing device according to an embodiment of the present application;

FIG. 2 is a schematic diagram showing an exploded structure of a first battery expansion force testing device according to an embodiment of the present application;

FIG. 3 is a schematic diagram showing an exploded structure of a second battery expansion force testing device according to an embodiment of the present application;

fig. 4 is a schematic structural view of a third battery expansion force testing device according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of a fourth battery expansion force testing device according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of a battery applied to a battery module or a battery pack in the battery swelling force testing device according to the embodiment of the present application.

Reference numerals:

100. a battery; 110. a housing; 111. a case; 112. a top cover; 120. a core; 130. a wire through hole;

200. a membrane pressure sensor;

300. monitoring equipment;

400. a data line;

500. a clamp; 510. a first clamping plate; 520. a second clamping plate; 530. a rod piece; 540. a fastener; 550. a third clamping plate; 560. a metal pressure sensor;

600. and a buffer member.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present application based on the embodiments herein.

As shown in fig. 1 to 4, the battery expansion force testing device provided in the embodiments of the present application is configured to detect an expansion force inside a battery 100, where the battery 100 includes a housing 110 and a core 120, a wire through hole 130 is formed in the housing 110, and the core 120 is disposed in the housing 110; the battery expansion force testing device includes a membrane pressure sensor 200, a monitoring apparatus 300, and a data line 400. The film pressure sensor 200 is configured to be disposed inside the core 120 and/or between the core 120 and the housing 110; the monitoring device 300 is used for monitoring pressure information of the film pressure sensor 200; the data line 400 penetrates the case 110 through the line hole 130, one end of the data line 400 is connected to the thin film pressure sensor 200, the other end is connected to the monitoring device 300, and the line hole 130 is sealed by a sealing member.

The thin film pressure sensor 200 used in the above embodiment can be freely bent, has good flexibility, is sensitive to pressure detection, and can be made particularly thin in size, so that it can directly contact with the surface to be measured, reduce the occupation of the internal space of the battery 100, quickly sense the pressure change condition, and quickly transmit the measured pressure signal to the monitoring device. In addition, in order to accommodate the working environment inside the battery 100, the thin film pressure sensor 200 has characteristics of high temperature resistance and acid-base corrosion resistance.

In the above embodiment, the film pressure sensor 200 is used to be disposed inside the case 110 of the battery 100, and the pressure data inside the battery 100 can be directly obtained through the film pressure sensor 200, and transmitted to the external monitoring device directly through the data line 400, and the expansion force data inside the battery 100 can be intuitively obtained through the monitoring device. Because the film pressure sensor 200 is disposed inside the housing 110, compared with the technical scheme of disposing the pressure testing device outside the housing 110 in the related art, the interference and influence of the thickness and hardness of the housing 110 on the expansion force testing result can be eliminated, so that the obtained expansion force data is more accurate. Specifically, the film pressure sensor 200 may be selectively disposed inside the core 120 to directly obtain pressure information inside the core 120; as shown in fig. 3, the film pressure sensor 200 may be disposed between the housing 110 and the core 120 to directly obtain pressure information between the housing 110 and the core 120; alternatively, the film pressure sensor 200 may be disposed between the case 110 and the core 120, and inside the core 120, so that pressure information at a plurality of positions within the case 110 of the battery 100 may be obtained.

In the above embodiment, the internal mode of the film pressure sensor 200 is adopted to directly and accurately obtain the expansion stress data in the casing 110, the battery expansion force testing device can be adopted to continuously monitor the expansion stress data in the casing 110 of the battery 100, and according to the continuously monitored expansion stress data, a relational function can be established for estimating and calculating the battery 100, the module SOC and the service life, and for estimating and calculating the internal space of the battery 100 to be reserved and the gap between the battery 100 and the battery 100 in the module, so as to optimize the constraint force used by the battery 100 during the module assembly, thereby providing data support for improving the module performance and the service life of the battery 100.

In the above embodiment, the thin film pressure sensor 200 realizes data interaction with the monitoring device through the data line 400, and compared with a wireless transmission mode, timeliness and quick response of the data interaction can be improved. The data line 400 passes through the casing 110 through the wire passing hole 130, and the wire passing hole 130 is sealed through a sealing member, so that a sealed environment is formed inside the casing 110, and the pressure information obtained by the film pressure sensor 200 comprises the pressure information caused by the expansion of the gas in the casing 110, so that the test data is more close to the working reality of the battery 100, and has more definite guiding significance for the design of the battery 100. The seal is preferably a high temperature, acid and alkali corrosion resistant sealant such as an epoxy glue, a high strength AB glue.

Alternatively, the casing 110 may be designed as a split structure, for example, as shown in fig. 1-3, where the casing 110 includes a casing 111 and a top cover 112, the casing 111 is a top opening structure, the top cover 112 is matched with the opening of the casing 111, the core 120 is disposed in a cavity formed by surrounding the casing 111 and the top cover 112, and the wire through hole 130 may be formed in the top cover 112, that is, the data wire 400 connected with the film pressure sensor 200 in the casing 110 is led out from the top cover 112.

In some embodiments, as shown in fig. 2 and 3, the core 120 is provided in plurality, and the thin film pressure sensor 200 is further configured to be disposed between adjacent cores 120. By arranging the film pressure sensor 200 between the cores 120, the information of the pressure and the pressure change between the adjacent cores 120 can be accurately obtained, and can be used for estimating and calculating the gap between the cores 120 and the cores 120 in the battery 100 to be reserved, so as to optimize the structure and the performance of the battery 100.

In some embodiments, core 120 is a winding core formed by pole pieces. Optionally, the core 120 is a winding core set in a winding form by a pole piece, the film pressure sensor 200 is attached to the pole piece, in the production process, the pole piece is wound by a winding machine to form the winding core, the film pressure sensor 200 is put into the winding core, the prepared winding core is subjected to procedures of hot pressing, ultrasonic welding of a tab and the like, and then the winding core is wrapped by an insulating film and put into the battery 100 shell 110. Optionally, the core 120 is a winding core that is set in a lamination manner by a pole piece, the film pressure sensor 200 is attached to the pole piece, in the production process, the pole piece is laminated by a lamination machine, the film pressure sensor 200 is put into the winding core, the prepared winding core is subjected to procedures of hot pressing, ultrasonic welding of a tab and the like, and then the winding core is wrapped by an insulating film and put into the battery 100 shell 110. Whether the winding core is formed in a laminated form or in a winding manner, after the winding core is put into the housing 110, the top cover 112 is drilled to form the wire through hole 130, the data wire 400 of the film pressure sensor 200 passes through the wire through hole 130 to be connected with the external monitoring equipment 300, the drilled hole is connected with the external monitoring equipment through a sealing element, and finally the battery 100 is manufactured after a series of procedures of laser welding of the top cover 112, airtight inspection, baking, liquid injection, formation, liquid supplement, volume division and the like.

In the case where the film pressure sensor 200 is built in the winding core, the expansion force change of each point on the surface of the pole piece attached to the film pressure sensor can be accurately measured. The thin film pressure sensor 200 is preferably arranged parallel to the large surface of the winding core, the large surface of the winding core is understood to be the surface with a large area of the winding core structure, and thus the advantage of large thickness and large area of the thin film pressure sensor 200 can be fully utilized, the large contact area with the pole piece is realized, and the pressure information of multiple points on the surface of the pole piece is obtained.

In the above embodiment, the winding core has the effect of forming a plurality of layers of pole pieces in the thickness direction, after the film pressure sensor 200 is arranged on a certain two adjacent layers of pole pieces, the expansion force of each point on the surface of the other layers of pole pieces is changed along with the distance from the film pressure sensor 200, so that the expansion force is difficult to accurately monitor by the film pressure sensor 200, the winding core is thicker along with the increasing volume of the battery 100, and the expansion force of the surface of the pole piece, which is far from the film pressure sensor 200, on the winding core is harder to accurately monitor by the sensor. Based on this, as shown in fig. 3, in order to obtain the expansion force data of the surface of the multi-layer pole piece on the winding core, a plurality of film pressure sensors 200 may be placed on the winding core, so as to monitor the expansion force data of different positions of the winding core at the same time, that is, a plurality of film pressure sensors 200 are disposed in the winding core, and the plurality of film pressure sensors 200 are distributed at intervals in the thickness direction of the winding core. In addition, by placing a plurality of film pressure sensors 200 into the winding core, expansion force data of a plurality of layers of pole pieces in the winding core can be obtained. According to the measured expansion force data of the plurality of layers of pole pieces, not only can the expansion force information corresponding to the surfaces of the pole pieces be obtained, but also the three-dimensional expansion force data of the winding core can be formed, namely, the expansion force data of the surfaces of the plurality of layers of pole pieces form the three-dimensional expansion force data of the winding core, so that the three-dimensional expansion force data can be used for simulating expansion changes of the battery 100, the winding core and the pole pieces, and the design, the module assembly and the like of the battery 100 are optimized.

In some embodiments, the core 120 is in the form of a single-layer pole piece or a double-layer pole piece, with the thin film pressure sensor 200 disposed between the housing 110 and the pole piece. Alternatively, the core 120 is only a single-layer pole piece, and the battery 100 is configured as a half battery 100 or a symmetrical battery 100, and the thin film pressure sensor 200 is disposed in the casing 110 of the half battery 100 and is attached to the pole piece. Optionally, the chip is a double-layer pole piece, specifically including a positive pole piece and a negative pole piece, and the battery 100 is a full battery 100, and the thin film pressure sensor 200 is arranged between the casing 110 of the full battery 100 and the pole piece and is attached to the pole piece. The thickness of the pole piece can change during charge and discharge, which shows that the pole piece has different expansions, and the expansion of the pole piece can be tested through the film pressure sensor 200. For convenience of testing, a single-layer pole piece can be used for testing. The single-layer pole piece is only 1 positive pole piece or 1 negative pole piece, and one lithium piece is added during testing, so that the positive pole piece is measured in the form of positive pole piece, diaphragm and lithium piece, or the negative pole piece is measured in the form of negative pole piece, diaphragm and lithium piece. The double-layer electrode plate is characterized by comprising a positive electrode plate and a negative electrode plate, and the expansion of the electrode plate is measured in the form of positive electrode plate, diaphragm and negative electrode plate. In this embodiment, the expansion force data of each point on the single Zhang Jipian can be accurately measured, and the data can be applied to the analysis and characterization of the indexes such as whether the slurry is uniformly stirred, whether the pole piece is uniformly coated, the SOC state of the battery 100, and whether the pole piece is out of lithium.

It should be noted that, the battery 100 in the battery expansion force testing device in the present application may be a hard-pack battery 100 or a soft-pack battery 100, the casing 110 of the hard-pack battery 100 includes, but is not limited to, an aluminum casing, and the casing 110 of the soft-pack battery 100 includes, but is not limited to, an aluminum-plastic film, through which the data line 400 in the present application will penetrate.

In some embodiments, as shown in fig. 4, the battery expansion force testing device further includes a clamp 500, the clamp 500 including a first clamping plate 510, a second clamping plate 520, a rod 530, and a fastener 540, the first clamping plate 510 and the second clamping plate 520 are sleeved on the rod 530, the battery 100 is disposed between the first clamping plate 510 and the second clamping plate 520, and the fastener 540 cooperates with the rod 530 to clamp the battery 100 between the first clamping plate 510 and the second clamping plate 520. According to the test requirement, the battery 100 can be placed between the first clamping plate 510 and the second clamping plate 520, a certain total pressure is applied after the battery is locked by the fastening belt, then the expansion force data of the inside of the battery 100 can be obtained according to the built-in film pressure sensor 200 of the battery 100, and the influence of the housing 110 on the expansion force can be obtained through the difference value of the two. In other words, the built-in film pressure sensor 200 is combined with the fixture 500, and the monitored expansion force of the battery 100 can be checked and decomposed, so that expansion force data inside the housing 110, the influence of the housing 110 on the expansion force, and the like can be obtained. Preferably, a thin film pressure sensor 200 may be provided between the jig 500 and the case 110 of the battery 100, and the thin film pressure sensor 200 is also connected to the monitoring device 300 through the data line 400, so that the total pressure applied to the battery 100 by the jig 500 can be precisely obtained.

Specifically, the rod 530 may be a plurality of bolts, for example, four bolts are disposed in parallel as shown in fig. 4 of the present application, so as to improve the stability of the first clamping plate 510 and the second clamping plate 520. The fastener 540 is preferably a nut that mates with a bolt, the second clamping plate 520 is fixedly connected to the bolt, the first clamping plate 510 is slidably mated to the bolt, and the nut mates with the bolt on a side of the first clamping plate 510 facing away from the second clamping plate 520, thereby clamping the battery 100 between the first clamping plate 510 and the second clamping plate 520. In this embodiment, the total pressure applied can be determined by the screwing position of the nut, and it is of course possible to obtain more accurate total pressure by providing the film pressure sensor 200 between the jig 500 and the battery 100 in the foregoing embodiment.

In another embodiment, as shown in fig. 5, the fixture 500 includes the fixture 500 including a first clamping plate 510, a second clamping plate 520, a rod 530, a fastener 540, a third clamping plate 550, and a metal pressure sensor 560, wherein the first clamping plate 510, the second clamping plate 520, and the third clamping plate 550 are all sleeved on the rod 530, the battery 100 is disposed between the first clamping plate 510 and the second clamping plate 520, the fastener 540 cooperates with the rod 530 to clamp the battery 100 between the first clamping plate 510 and the second clamping plate 520, and is located on a side of the second clamping plate 520 facing away from the first clamping plate 510, the metal pressure sensor 560 is disposed between the second clamping plate 520 and the third clamping plate 550, and the metal pressure sensor 560 is electrically connected with the monitoring device 300. The rod 530 may preferably be a bolt, the fastener 540 preferably be a nut that mates with the bolt, the third clamping plate 550 is fixedly connected to the bolt, the first clamping plate 510 and the second clamping plate 520 are slidably mated to the bolt, and the nut mates with the bolt on a side of the first clamping plate 510 facing away from the second clamping plate 520, thereby clamping the battery 100 between the first clamping plate 510 and the second clamping plate 520. In the present embodiment, the metal pressure sensor 560 is used to monitor the total pressure applied to the battery 100 by the jig 500, thereby cooperating with the film pressure sensor 200 built in the battery 100 to obtain the expansion force data inside the case 110 and the influence of the case 110 on the expansion force.

In some embodiments, as shown in fig. 6, the battery 100 in the battery swelling force testing device of the embodiment of the present application may also be applied to a battery module and a battery pack. In practical applications, a buffer 600 such as a rubber pad, a heat insulation pad, and aerogel may be further placed between the batteries 100 and the battery 100 in the assembled battery module or battery pack.

In the description of the present utility model, it should be understood that the terms "upper", "lower", "left", "right", "inner", "outer", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, features defining "first", "second" may include one or more such features, either explicitly or implicitly. In the description of the present utility model, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Claims (10)

1. A battery expansion force testing device for detecting expansion force inside a battery (100), the battery (100) comprises a shell (110) and a core body (120), a wire passing hole (130) is formed in the shell (110), and the core body (120) is arranged in the shell (110), and the battery expansion force testing device is characterized in that:

a film pressure sensor (200) for being arranged inside the core (120) and/or between the core (120) and the housing (110);

-a monitoring device (300) for monitoring pressure information of the membrane pressure sensor (200);

and the data wire (400) penetrates through the shell (110) through the wire through hole (130), one end of the data wire (400) is connected with the film pressure sensor (200), and the other end of the data wire is connected with the monitoring equipment (300).

2. The battery expansion force testing device according to claim 1, wherein the wire through hole (130) is sealed by a sealing member, the sealing member being a material resistant to high temperature, acid and alkali corrosion.

3. The battery expansion force testing device according to claim 1, wherein the battery (100) comprises a plurality of cores (120), the film pressure sensor (200) further being adapted to be disposed between adjacent cores (120).

4. The battery expansion force testing device according to claim 1, wherein the core (120) is a winding core provided in a wound form by a pole piece or a winding core provided in a laminated form by a pole piece, and the film pressure sensor (200) is provided in a laminated form with the pole piece.

5. The battery swelling force testing device according to claim 4, wherein a plurality of the film pressure sensors (200) are provided in the winding core, and the plurality of the film pressure sensors (200) are arranged to be spaced apart in the thickness direction of the winding core.

6. The battery expansion force testing device according to claim 1, wherein the core (120) is a single-layer pole piece or a double-layer pole piece, and the film pressure sensor (200) is configured to be disposed between the housing (110) and the pole piece.

7. The battery expansion force testing device according to any one of claims 1 to 6, wherein the housing (110) is an aluminum case or an aluminum plastic film, and the data line (400) penetrates through the aluminum case or the aluminum plastic film.

8. The battery expansion force testing device according to any of claims 1-6, further comprising a clamp (500), the clamp (500) comprising a first clamp plate (510), a second clamp plate (520), a rod (530) and a fastener (540), the first clamp plate (510) and the second clamp plate (520) being sleeved on the rod (530), the first clamp plate (510) and the second clamp plate (520) being for clamping the battery (100), the fastener (540) cooperating with the rod (530) to clamp the battery (100) between the first clamp plate (510) and the second clamp plate (520).

9. The battery expansion force testing device according to claim 8, wherein the film pressure sensor (200) is further configured to be disposed between the clamp (500) and the housing (110) of the battery (100).

10. The battery expansion force testing device according to claim 8, wherein the clamp (500) further comprises a third clamping plate (550) and a metal pressure sensor (560), the third clamping plate (550) is sleeved on the rod (530) and is located at one side of the second clamping plate (520) away from the first clamping plate (510), the metal pressure sensor (560) is disposed between the second clamping plate (520) and the third clamping plate (550), and the metal pressure sensor (560) is electrically connected with the monitoring device (300).

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