Battery cell expansion displacement detection device
By designing a cell expansion displacement detection device, the shortcomings in the assessment of expansion displacement during cell thermal runaway are solved, enabling accurate detection of cell movement trajectory, reducing the risk of secondary short circuits, and improving battery safety and the integrity of test data.
Patent Information
- Application Number
- CN202520069928.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-13
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2035-01-13
AI Technical Summary
The existing technology lacks the ability to assess the specific trajectory of cell expansion and displacement during thermal runaway, which may lead to secondary short circuits after cell expansion and displacement, affecting battery safety.
A battery cell expansion displacement detection device was designed, including a detection platform, a displacement section, a pressure detection component, a limiting component, and a controller. The expansion displacement of the battery cell is detected by sliding the displacement section, and the displacement section is locked when the expansion force exceeds a threshold. The displacement is read by using etched lines. The device is combined with a limiting block and an electric push rod to prevent the influence of non-expansion forces and improve the detection accuracy.
It enables the assessment of the specific activity trajectory during the thermal runaway of the battery cell, reduces the risk of secondary short circuits, improves the integrity and accuracy of the cell expansion test data, and enhances the safety of the battery.
Smart Images
Figure CN223610773U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery testing technology, and in particular to a battery cell expansion displacement detection device. Background Technology
[0002] As the main power source for new energy vehicles, the safety and reliability of power batteries are the two most critical parameters. During vehicle operation, the battery cell, as the smallest unit, will expand due to long-term charging and discharging, which will cause the square battery cell to generate a certain expansion force and expansion displacement, and the volume of the battery cell will also expand proportionally.
[0003] In related technologies, the thermal runaway test and evaluation of battery cells mostly focus on the thermal runaway trigger time and whether the battery cell catches fire after thermal runaway, but lacks an evaluation of the specific activity trajectory of the battery cell during the thermal runaway process. Utility Model Content
[0004] In view of this, the present invention aims to provide a battery cell expansion displacement detection device to detect the dynamic expansion displacement of the battery cell.
[0005] To achieve the above objectives, the technical solution of this utility model is implemented as follows:
[0006] A battery cell expansion displacement detection device, comprising:
[0007] A testing platform is used to support and fix battery cell groups, which are composed of multiple square battery cells stacked along their width.
[0008] The displacement part is provided in four slidable parts on the detection platform, and is respectively attached to the four side surfaces of the battery cell assembly, and is slidably intersecting each other in a "well" shape;
[0009] When the battery cell assembly expands, it can push against the sliding displacement portion to represent the amount of expansion displacement.
[0010] Furthermore, the displacement portion comprises two first displacement portions and two second displacement portions; the two first displacement portions respectively abut against both ends of the cell assembly in the length direction of the square cell and are provided with elongated holes extending in the width direction of the square cell; the two second displacement portions respectively abut against both ends of the cell assembly in the width direction of the square cell and have sliding ends passing through the elongated holes; the sliding distance of the sliding ends along the length direction of the elongated holes is greater than the theoretical expansion displacement of the cell assembly in the width direction of the square cell.
[0011] Furthermore, each of the first displacement portions has a limiting portion within its elongated hole to restrict the movement of the sliding end along the width direction of the square battery cell.
[0012] Further, the limiting part is a guide rail, and the sliding end is slidably connected to the guide rail.
[0013] Further, a plurality of first scale lines for detecting the displacement of the sliding end are arranged on the first displacement part provided with the limiting part.
[0014] Further, the battery cell expansion displacement detection device further comprises a pressure detection assembly, a limiting assembly and a controller; the pressure detection assembly is clamped between the displacement part and the battery cell group; the limiting assembly is used for locking the movement of the displacement part; the controller is electrically connected to the pressure detection assembly and the limiting assembly; when the expansion force of the battery cell group received by the controller from the pressure detection assembly exceeds a set threshold value, the limiting assembly can be controlled to unlock the displacement part.
[0015] Further, the pressure detection assembly comprises a pressure sensor and a connecting plate; the connecting plate contacts the battery cell group; and the pressure sensor is arranged between the connecting plate and the displacement part.
[0016] Further, the limiting assembly comprises an electric push rod and a limiting block; the limiting block is slidably arranged on the detection platform and can at least partially penetrate out of the detection platform under the driving of the electric push rod to block the displacement part.
[0017] Further, the sliding direction of the limiting block on the detection platform gradually approaches the battery cell group from bottom to top.
[0018] Further, each displacement part is correspondingly provided with two spaced limiting blocks.
[0019] Compared with the prior art, the utility model has the following advantages:
[0020] The battery cell expansion displacement detection device can detect the expansion of the square battery cell in four directions, evaluate the specific activity track of the battery cell in the thermal runaway process of the battery cell, reduce the secondary short circuit caused by the expansion displacement of the battery cell after thermal runaway, complete the detection of the dynamic expansion displacement of the battery cell, and improve the completeness of the test data of the battery cell expansion.
[0021] And, by setting the displacement part as a first displacement part and a second displacement part, setting a long hole extending along the width direction of the square cell on the first displacement part, and setting sliding ends penetrating in the long hole at both ends of the second displacement part, when the cell expands along its width direction, i.e. in the stacking direction of the cell group, the second displacement part slides along the direction in which the long hole is opened; when the cell expands along its length direction, the sliding ends slide in the long hole; so as to realize the detection of the expansion displacement of the four sides of the cell group, and realize the detection of the dynamic expansion displacement of the cell. By setting the limiting part, the second displacement part slides along the direction in which the long hole is opened without deflection, so as to improve the accuracy of the detection data.
[0022] In addition, by setting the first scale line on the first displacement part, the deformation amount of the cell group in the width direction of the square cell, i.e. in the stacking direction of the square cell, can be measured and read; by setting the second scale line on the second displacement part, the total deformation amount of the cell group in the length direction can be read. The setting of the first scale line and the second scale line at the same time facilitates reading the deformation amount values of the four sides of the cell group.
[0023] At the same time, by setting the pressure detection assembly, the limiting assembly and the controller, when the expansion force of the cell group exceeds the set threshold value, the controller controls the limiting assembly to lock the displacement part, so as to reduce the movement of the displacement part caused by forces other than the expansion force.
[0024] In addition, by setting the pressure detection assembly to include a connecting plate, when the square cell explodes, the setting of the connecting plate protects the pressure sensor from the impact of the cell explosion, and the connecting plate can transmit the expansion force generated by the part of the square cell that is not directly opposite the pressure sensor to the pressure sensor, so as to monitor the overall expansion displacement of the cell group. By setting the limiting assembly to include an electric push rod and a limiting block, when the expansion force of the cell group exceeds the threshold value, the controller controls the electric push rod, so as to realize the gradual contraction of the limiting block into the detection platform, and facilitates the setting of the size of the threshold value by the controller.
[0025] Secondly, by setting the sliding direction of the limiting block on the detection platform to gradually approach the cell group from bottom to top, when the electric push rod gradually contracts into the detection platform, the limiting block gradually moves away from the cell group, so as to realize that when the expansion force gradually increases, the limiting block gradually moves away from the cell group synchronously, without affecting the movement of the displacement part. BRIEF DESCRIPTION OF DRAWINGS
[0026] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The embodiments of the present application illustrated in the drawings are presented by way of example or for purpose of illustration, and not as limitations of the present application. In the drawings:
[0027] Figure 1 The overall structure schematic diagram described in the embodiments of the present application;
[0028] Figure 2 Part of the parts schematic diagram of the embodiment of the utility model;
[0029] Figure 3 For Figure 2 The local amplification schematic view of A part in the middle;
[0030] Figure 4 The cross-sectional view at the limiting assembly of the embodiment of the utility model.
[0031] Mark explanation:
[0032] 1, detection platform;101, accommodation groove;
[0033] 2, electric core group;201, square electric core;
[0034] 3, displacement part;301, first displacement part;3011, long hole;3012, limiting part;3012a, guide rail;3013, first scale line;302, second displacement part;3021, sliding end;3021a, guide groove;3022, second scale line;
[0035] 4, pressure detection assembly;401, pressure sensor;402, connecting plate;
[0036] 5, limiting assembly;501, electric push rod;502, limiting block;
[0037] 6, controller. Specific implementation
[0038] It should be noted that the embodiments in the utility model and the features in the embodiments can be combined with each other without conflict.
[0039] In the description of the utility model, it should be noted that if the terms such as "upper", "lower", "inner", "outer" and the like indicating orientation or positional relationship appear, it is based on the orientation or positional relationship shown in the drawing, and is only for the convenience of describing the utility model and simplifying the description, and is not indicative or implied that the indicated device or element must have a specific orientation, a specific orientation and operation, so it cannot be understood as a limitation on the utility model. In addition, if the terms such as "first", "second" appear, they are also used for the purpose of description, and cannot be understood as indicating or implying relative importance.
[0040] Further, in the description of the utility model, unless otherwise expressly limited, the terms "mounting", "connecting", "connection" and "connector" should be understood broadly. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood in combination with the specific circumstances.
[0041] The utility model will be described in detail below with reference to the drawings and in combination with embodiments.
[0042] The embodiment relates to a kind of battery swelling displacement detection device, to detect the dynamic swelling displacement of battery, to improve battery swelling test data integrity.
[0043] Overall structure, with reference to Figure 1 The battery swelling displacement detection device in the embodiment includes detection platform 1 and displacement part 3, detection platform 1 is used to bear fixed battery group 2, battery group 2 is stacked along the width direction of itself by multiple square batteries 201;Displacement part 3 is slidably provided with four on detection platform 1, and is respectively adhered to the four side vertical surfaces of battery group 2, and it is slidably crossed and presents "well" shape;When battery group 2 swells, displacement part 3 can be pushed to slide to show swelling displacement amount.
[0044] As set forth above, by placing battery group 2 in the space formed by detection platform 1 and displacement part 3, when square battery 201 swells, battery group 2 pushes displacement part 3 to slide to show swelling displacement amount, and can detect the swelling around square battery 201, realize the specific activity track of battery group 2 in the process of evaluating battery thermal runaway, to reduce the secondary short circuit caused by the swelling displacement of battery group 2 after thermal runaway, complete the detection of dynamic swelling displacement of battery, to improve battery swelling test data integrity.
[0045] Based on the above overall introduction, with reference to Figure 1 Specifically, displacement part 3 is in the form of rectangular plate, and displacement part 3 is wrapped around the outer periphery of battery group 2 to cover and coat the outer periphery of battery group 2. Because battery group 2 often generates high temperature and high pressure when swelling, displacement part 3 is made of high-temperature-resistant and rigid material, such as titanium alloy or zirconium diboride, so that it can withstand the high temperature generated by the explosion of battery group 2. Therefore, it can be known that the materials of other components of the battery swelling displacement detection device are also selected from high-temperature-resistant materials.
[0046] At the same time, it can be understood that, in order to facilitate the expansion force generated by the battery cell group 2 to push the displacement part 3 to slide, the displacement part 3 is hollow inside to reduce the weight of the displacement part 3 itself, and under the condition that the friction coefficient between the displacement part 3 and the detection platform 1 is unchanged, the friction between the displacement part 3 and the detection platform 1 is reduced to facilitate the movement of the displacement part 3.
[0047] As an implementable manner, referring to Figures 1 to 3 , the displacement part 3 is divided into two first displacement parts 301 and two second displacement parts 302; the two first displacement parts 301 respectively abut against two ends of the battery cell group 2 in the length direction of the square battery cell 201, and are provided with long hole 3011 extending in the width direction of the square battery cell 201; the two second displacement parts 302 respectively abut against two ends of the battery cell group 2 in the width direction of the square battery cell 201, and have sliding ends 3021 inserted in the long hole 3011; the slidable distance of the sliding end 3021 along the length direction of the long hole 3011 is greater than the theoretical expansion displacement of the battery cell group 2 in the width direction of the square battery cell 201.
[0048] By setting the displacement part 3 as the first displacement part 301 and the second displacement part 302, and setting the long hole 3011 extending in the width direction of the square battery cell 201 on the first displacement part 301, and setting the sliding end 3021 inserted in the long hole 3011 on both ends of the second displacement part 302, when the battery cell expands in the width direction thereof, that is, expands in the stacking direction of the battery cell group 2, the second displacement part 302 slides in the opening direction of the long hole 3011; when the battery cell expands in the length direction thereof, the sliding end 3021 slides in the long hole 3011; so as to realize the detection of the expansion displacement amount of the four sides of the battery cell group 2, and realize the detection of the dynamic expansion displacement of the battery cell.
[0049] As an implementable manner, the sliding end 3021 is in a rectangular columnar structure, and is fixedly connected with the second displacement part 302, and the fixed connection manner can be welding or one-piece forming or other manners, and the slidable distance of the long hole 3011 in the length direction is greater than the theoretical expansion displacement of the battery cell group 2 in the width direction of the square battery cell 201, which means that the length of the long hole 3011 is greater than the sum of the width of the sliding end 3021 and the slidable distance of the sliding end 3021 under the expansion force of the battery cell group 2. Specifically, in order to facilitate the insertion of the sliding end 3021 into the long hole 3011, the thickness of the sliding end 3021 is set to be less than the height of the long hole 3011, that is, there is a gap between the upper surface of the sliding end 3021 and the upper hole wall of the long hole 3011 when the battery cell group 2 is detected.
[0050] Based on the insertion of the sliding end 3021 in the long hole 3011, in order to improve the accuracy of the detection data, referring to Figures 1 to 3, any first displacement part 301 is provided with a limiting part 3012 in the long hole 3011, which limits the movement of the sliding end 3021 along the width direction of the square battery cell 201. The limiting part 3012 is a guide rail 3012a, and the sliding end 3021 is slidably connected to the guide rail 3012a. By providing the limiting part 3012, the second displacement part 302 can slide along the direction in which the long hole 3011 is opened without being deflected, thereby improving the accuracy of the detection data.
[0051] Specifically, the lower surface of the sliding end 3021 matched with the limiting part 3012 is provided with a guide groove 3021a, and the guide rail 3012a is inserted into the guide groove 3021a. On the basis of providing the limiting part 3012, the distance between the upper surface of the sliding end 3021 and the upper hole wall of the long hole 3011 is not less than the thickness of the guide rail 3012a, so as to realize the insertion of the sliding end 3021 into the long hole 3011 and the cooperation of the guide rail 3012a with the guide groove 3021a.
[0052] It can be understood that, in order to facilitate reading the displacement amount of the first displacement part 301 and the second displacement part 302, the first displacement part 301 provided with the limiting part 3012 is provided with a plurality of first scale lines 3013 for detecting the displacement amount of the sliding end 3021; the sliding end 3021 of the second displacement part 302 away from the limiting part 3012 is provided with a plurality of second scale lines 3022, which are used to detect the displacement amount of the first displacement part 301 without the limiting part 3012.
[0053] By providing the first scale line 3013 on the first displacement part 301, the deformation amount of the battery cell group 2 in the width direction of the square battery cell 201, i.e. the stacking direction of the square battery cell 201, can be measured and read; by providing the second scale line 3022 on the second displacement part 302, the total deformation amount of the battery cell group 2 in the length direction can be read. The simultaneous provision of the first scale line 3013 and the second scale line 3022 facilitates reading the deformation amount values of the four sides of the battery cell group 2. Compared with the conventional provision of displacement sensors to feedback displacement data, the damage of the displacement sensors caused by the unpredictable thermal spewing and explosion in the thermal runaway process of the battery cell group 2 is avoided, thereby improving the use stability of the battery cell swelling displacement detection device. In order to improve the accurate collection of the swelling displacement amount, specifically, the scale interval of the first scale line 3013 and the second scale line 3022 is millimeter level.
[0054] In order to make the battery cell group 2 reach a certain swelling force, the limiting part 3012 is provided with a limiting part 3012, which is used to limit the movement of the sliding end 3021 along the width direction of the square battery cell 201. Figures 1 to 3The cell expansion displacement detection device only shows the expansion of the cell group 2 as an expansion displacement amount, and further comprises a pressure detection assembly 4, a limiting assembly 5 and a controller 6; the pressure detection assembly 4 is clamped between the displacement part 3 and the cell group 2, the limiting assembly 5 is used for locking the movement of the displacement part 3, and the controller 6 is electrically connected with the pressure detection assembly 4 and the limiting assembly 5; when the expansion force of the cell group 2 received by the controller 6 from the pressure detection assembly 4 exceeds a set threshold value, the limiting assembly 5 can be controlled to release the locking of the displacement part 3. By setting the pressure detection assembly 4, the limiting assembly 5 and the controller 6, when the expansion force of the cell group 2 exceeds the set threshold value, the controller 6 controls the locking of the limiting assembly 5 to the displacement part 3, so as to reduce the movement of the displacement part 3 caused by the force other than the expansion force.
[0055] It can be understood that the setting of the threshold value determines whether the displacement part 3 will slip under the action of the expansion force of the cell group 2. As an implementable way, specifically, the threshold value can be set equal to the expansion development pressure of the square cell 201. That is, when the pressure detected by the pressure detection assembly 4 is less than the threshold value, the displacement part 3 is in a locked state under the action of the limiting assembly 5, and when the pressure detected by the pressure detection assembly 4 is greater than the threshold value, the locking is released.
[0056] As an implementable way, the pressure detection assembly 4 comprises a pressure sensor 401 and a connecting plate 402; the connecting plate 402 contacts the cell group 2, and the pressure sensor 401 is arranged between the connecting plate 402 and the displacement part 3. By setting the pressure detection assembly 4 to comprise the connecting plate 402, when the square cell 201 explodes, the connecting plate 402 protects the pressure sensor 401 from the impact of the cell explosion, and the connecting plate 402 can transmit the expansion force generated by the part of the square cell 201 not directly opposite the pressure sensor 401 to the pressure sensor 401, so as to realize monitoring the overall expansion displacement of the cell group 2.
[0057] Specifically, referring to Figures 1 to 4 The limiting assembly 5 comprises an electric push rod 501 and a limiting block 502; the limiting block 502 is slidably arranged on the detection platform 1 and can at least partially penetrate out of the detection platform 1 under the driving of the electric push rod 501 to block the displacement part 3. By setting the limiting assembly 5 to comprise the electric push rod 501 and the limiting block 502, when the expansion force of the cell group 2 exceeds the threshold value, the controller 6 controls the electric push rod 501 to realize the gradual contraction of the limiting block 502 into the detection platform 1, and the size of the threshold value can be conveniently set by the controller 6.
[0058] Based on the setting of the limiting component 5 including the electric push rod 501 and the limiting block 502, the sliding direction of the limiting block 502 on the detection platform 1 gradually approaches the battery cell group 2 from bottom to top, and each displacement part 3 is provided with two spaced limiting blocks 502. By setting the sliding direction of the limiting block 502 on the detection platform 1 gradually approaching the battery cell group 2 from bottom to top, when the electric push rod 501 gradually shrinks into the detection platform 1, the limiting block 502 gradually moves away from the battery cell group 2, so that when the swelling force gradually increases, the swelling displacement gradually increases, the limiting block 502 synchronously gradually moves away from the battery cell group 2, without affecting the movement of the displacement part 3. Specifically, the detection platform 1 is provided with a containing groove 101, and the electric push rod 501 and the limiting block 502 are located in the containing groove 101. The containing groove 101 is in an inclined state, so that the contact surface of the limiting block 502 and the displacement part 3 is a vertical plane.
[0059] The battery cell swelling displacement detection device described in the embodiment of the application places the battery cell group 2 in the space formed by the displacement part 3 and the detection platform 1 when detecting the swelling force of the battery cell group 2. When the battery cell group 2 swells and the swelling force gradually increases, the swelling force is transmitted to the controller 6 through the pressure sensor 401. When the swelling force is greater than the set threshold value, the controller 6 adjusts the connecting plate 402 to gradually shrink into the detection platform 1 through the electric push rod 501. If the battery cell group 2 swells along the width direction of the square battery cell 201, the sliding end 3021 connected to the second displacement part 302 slides in the long hole 3011. If the battery cell group 2 swells along the length direction of the square battery cell 201, the first limiting part 3012 without the limiting part 3012 slides along the length direction of the sliding end 3021. The swelling displacement of the battery cell group 2 is read by the first scale line 3013 and the second scale line 3022, which is convenient for introducing the detected displacement into the design review and failure analysis to determine whether other components are interfered. The heat swelling resistance of the battery cell group 2 is verified and the risk is evaluated.
[0060] The battery cell group 2 pushes the displacement part 3 to slide and show the swelling displacement, and can detect the swelling of the square battery cell 201 around, realize the evaluation of the specific activity track of the battery cell in the process of thermal runaway of the battery cell, reduce the secondary short circuit caused by the swelling displacement of the battery cell after thermal runaway, complete the detection of the dynamic swelling displacement of the battery cell, and improve the completeness of the swelling test data of the battery cell.
[0061] The above only describes the preferred embodiment of the application, and does not limit the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.
Claims
1. A cell swelling displacement detection device characterized by comprising: include: A testing platform is used to support and fix battery cell groups, which are composed of multiple square battery cells stacked along their width. The displacement part is provided in four slidable parts on the detection platform, and is respectively attached to the four side surfaces of the battery cell assembly, and is slidably intersecting each other in a "well" shape; When the battery cell assembly expands, it can push against the sliding displacement portion to represent the amount of expansion displacement.
2. The cell expansion displacement detection device according to claim 1, characterized in that: The displacement portion consists of two first displacement portions and two second displacement portions; The two first displacement portions respectively abut against the two ends of the cell assembly in the length direction of the square cell, and are provided with elongated holes extending in the width direction of the square cell; the two second displacement portions respectively abut against the two ends of the cell assembly in the width direction of the square cell, and have sliding ends passing through the elongated holes; The sliding distance of the sliding end along the length of the elongated hole is greater than the theoretical expansion displacement of the cell assembly in the width direction of the square cell.
3. The cell expansion displacement detection device according to claim 2, characterized in that: Each of the first displacement portions has a limiting portion in its elongated hole that restricts the movement of the sliding end along the width direction of the square battery cell.
4. The cell expansion displacement detection device according to claim 3, characterized in that: The limiting part is a guide rail, and the sliding end is slidably connected to the guide rail.
5. The cell expansion displacement detection device according to claim 3, characterized in that: The first displacement portion, which has the limiting portion, is provided with multiple first graduations for detecting the displacement of the sliding end; and / or, The sliding end of the second displacement portion, which is away from the limiting portion, is provided with multiple second markings. The second markings are used to detect the displacement of the first displacement portion, which does not have the limiting portion.
6. The cell expansion displacement detection device according to claim 1, characterized in that: Includes pressure detection components, limit components, and controllers; The pressure detection component is sandwiched between the displacement part and the battery cell assembly, the limiting component is used to lock the movement of the displacement part, and the controller is electrically connected to the pressure detection component and the limiting component; When the expansion force of the battery cell assembly received by the controller from the pressure detection component exceeds a set threshold, it can control the limiting component to release the locking of the displacement portion.
7. The cell expansion displacement detection device according to claim 6, characterized in that: The pressure detection assembly includes a pressure sensor and a connecting plate; The connecting plate contacts the battery cell assembly, and the pressure sensor is disposed between the connecting plate and the displacement part.
8. The cell expansion displacement detection device according to claim 6, characterized in that: The limiting assembly includes an electric push rod and a limiting block; The limiting block is slidably mounted on the detection platform and can at least partially extend out of the detection platform under the drive of the electric push rod to block the displacement portion.
9. The cell expansion displacement detection device according to claim 8, characterized in that: The sliding direction of the limiting blocks on the detection platform gradually approaches the battery cell group from bottom to top.
10. The battery cell swelling displacement detection device according to claim 8, characterized in that: Two spaced limiting blocks are arranged corresponding to each displacement part.