A test device for triggering heat runaway diffusion of square lithium battery overcharge
The lithium battery test device, designed with a screw pressure system and a detachable heat insulation plate array, solves the problems of high cost and safety risks in lithium battery module thermal runaway propagation testing, and realizes low-cost, high-safety thermal runaway propagation testing under simulated module confinement conditions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGSU HIGEE ENERGY CO LTD
- Filing Date
- 2025-07-02
- Publication Date
- 2026-07-07
AI Technical Summary
Existing thermal runaway propagation tests for lithium battery modules are costly and pose safety risks, and cannot realistically simulate the mechanical confinement conditions of the modules.
A test device for thermal runaway propagation triggered by overcharge of square lithium batteries was designed by using a screw pressure system to simulate the binding force of the module and combining it with a detachable heat insulation plate array. The device was tested for thermal runaway triggering and propagation at the single-cell level.
It reduces testing costs, improves safety, and can simulate module thermal runaway propagation under real conditions, reducing the number of individual cell tests and ensuring test results.
Smart Images
Figure CN224471817U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of lithium battery testing technology, and in particular to a test device for overcharge-triggered thermal runaway propagation of square lithium batteries. Background Technology
[0002] Lithium-ion battery systems are composed of a large number of cells and modules. If even one or two cells go out of control, the battery will fail and then cause safety problems through thermal runaway. Therefore, it is crucial for lithium-ion batteries to pass thermal runaway propagation tests.
[0003] Currently, when conducting thermal runaway propagation tests on lithium battery modules, the "Thermal Runaway Propagation Performance Test" in the national standard GB / T36276-2023 Thermal Safety Performance Test is typically used. This method uses an overcharge-triggered approach, with the battery cell at the center of the lithium battery module as the thermal runaway trigger. Its positive and negative terminals are connected to the charging and discharging device and its voltage data sampling lines, while maintaining the thermal runaway trigger point connected to adjacent battery cells. However, the existing test method has several drawbacks:
[0004] (1) High testing cost: The module is used as the test sample. The module is usually composed of more than a dozen individual cells. Too many individual cells are lost, which increases the test cost.
[0005] (2) High safety risk: When the module is used as the test sample, a chain reaction occurs when the test fails, which poses a great safety hazard.
[0006] (3) Distortion of working condition simulation: Independent unit test cannot simulate the mechanical constraint conditions of the module.
[0007] How to reduce the test cost without affecting the test results and ensure the safety of the test process has become an urgent problem to be solved. Therefore, this utility model proposes a test device for thermal runaway propagation triggered by overcharging of square lithium batteries. Utility Model Content
[0008] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a test device for thermal runaway propagation triggered by overcharging of square lithium batteries. It has the advantages of low cost and high safety, and solves the problems of high cost and high risk in module testing.
[0009] The purpose of this utility model is achieved as follows:
[0010] A test device for overcharge-triggered thermal runaway propagation of square lithium batteries includes a frame, a lithium battery assembly, a flat pressure plate, a guide column assembly, and a drive mechanism. The frame includes a base plate and a left fixing plate and a right fixing plate arranged parallel to each other at both ends of the base plate. The left fixing plate and the right fixing plate are respectively vertically arranged at the left and right ends of the base plate.
[0011] A parallel planar pressure plate is provided between the left and right fixed plates. The planar pressure plate is slidably disposed between the left and right fixed plates through a guide post assembly. The planar pressure plate is driven by a driving mechanism.
[0012] A lithium battery assembly is disposed between the flat pressure plate and the left fixed plate. The lithium battery assembly includes no less than three individual cells arranged side by side, and a heat insulation plate is provided between two adjacent individual cells. The heat insulation plate is in close contact with the individual cells on both sides.
[0013] Preferably, the guide post assembly includes a first guide post, a second guide post, a third guide post, and a fourth guide post. The first and fourth guide posts are symmetrically arranged at the bottom ends of the left and right fixing plates, and the second and third guide posts are symmetrically arranged at the top ends of the left and right fixing plates.
[0014] Preferably, one end of the first guide post, the second guide post, the third guide post, and the fourth guide post is fixed to the left fixed plate, and the other end extends through the flat pressure plate and out of the right fixed plate and is fixed by bolts, so as to realize the sliding of the flat pressure plate on the guide post assembly.
[0015] Preferably, the driving mechanism includes a screw and a handwheel. One end of the screw is connected to the center of the flat pressure plate, and the other end is threaded to the right fixed plate and extends out of the right fixed plate. The extended end is the bearing end to bear the external rotational driving force.
[0016] Preferably, the protruding end of the screw is connected to a handwheel, and the movement of the flat plate is driven by rotating the handwheel.
[0017] Preferably, the central cell in the lithium battery assembly is a central single cell, and the positive and negative terminals of the central single cell are connected to the charging and discharging device; a temperature acquisition line is connected to the center of the top surface of the central single cell of the lithium battery assembly, and a temperature acquisition line is connected to the center of the outer surface of the single cells on both sides, and each temperature acquisition line is connected to a temperature recorder.
[0018] Compared with the prior art, the beneficial effects of this utility model are:
[0019] This invention provides a test device for overcharge-triggered thermal runaway propagation of square lithium batteries. It simulates the module binding force through a screw pressure system and, in conjunction with a detachable heat insulation plate array, achieves single-cell-level thermal runaway triggering and propagation testing. This invention has a simple structure, is easy to operate, is not restricted by the site, can simulate module thermal runaway propagation tests under real conditions to a high degree, reduces the number of single-cell battery tests, lowers test costs, does not affect test results, and ensures the safety of the test process. Attached Figure Description
[0020] Figure 1This is a schematic diagram of the structure of this utility model.
[0021] Figure 2 This is a side view of the present invention.
[0022] Figure 3 This is a top view of the present invention.
[0023] Figure 4 This is a schematic diagram of the structure of the lithium battery assembly of this utility model.
[0024] Figure 5 This is a schematic diagram showing the connection between the lithium battery assembly and the temperature recorder of this utility model.
[0025] In the picture:
[0026] Frame 100, left fixing plate 101, right fixing plate 102, lithium battery assembly 200, single cell 201, heat insulation plate 202, flat pressure plate 300, guide post assembly 400, first guide post 401, second guide post 402, third guide post 403, fourth guide post 404, drive mechanism 500, screw 501, handwheel 502, temperature recorder 600. Detailed Implementation
[0027] To better understand the technical solution of this utility model, a detailed description will be provided below in conjunction with relevant illustrations. It should be understood that the specific embodiments described below are not intended to limit the specific implementation of the technical solution of this utility model, but are merely possible implementations of the technical solution of this utility model. It should be noted that the descriptions of the positional relationships of the components herein, such as component A being located above component B, are based on the relative positions of the components in the illustrations and are not intended to limit the actual positional relationships of the components. Example 1
[0028] See Figures 1-5 , Figure 1 A schematic diagram of a test device for overcharge-triggered thermal runaway propagation of a square lithium battery is shown. As shown in the figure, the test device for overcharge-triggered thermal runaway propagation of a square lithium battery in this embodiment 1 includes a frame 100, a lithium battery assembly 200, a flat pressure plate 300, a guide post assembly 400, and a drive mechanism 500. The frame 100 includes a base plate and a left fixing plate 101 and a right fixing plate 102 arranged parallel to each other at both ends of the base plate. The left fixing plate 101 and the right fixing plate 102 are respectively vertically arranged at the left and right ends of the base plate.
[0029] A parallel planar pressure plate 300 is provided between the left fixing plate 101 and the right fixing plate 102. The planar pressure plate 300 is slidably disposed between the left fixing plate 101 and the right fixing plate 102 via a guide post assembly 400. The planar pressure plate 300 is driven by a drive mechanism 500.
[0030] A lithium battery assembly 200 is disposed between the flat pressure plate 300 and the left fixed plate 101. The lithium battery assembly 200 includes no less than three individual cells 201, which are arranged side by side. A heat insulation plate 202 is provided between two adjacent individual cells 201, and the heat insulation plate 202 is in close contact with the individual cells 201 on both sides.
[0031] The guide post assembly 400 includes a first guide post 401, a second guide post 402, a third guide post 403, and a fourth guide post 404. The first guide post 401 and the fourth guide post 404 are symmetrically arranged at the bottom ends of the left fixing plate 101 and the right fixing plate 102, and the second guide post 402 and the third guide post 403 are symmetrically arranged at the top ends of the left fixing plate 101 and the right fixing plate 102.
[0032] One end of the first guide post 401, the second guide post 402, the third guide post 403 and the fourth guide post 404 are fixed on the left fixed plate 101, and the other end extends through the flat pressure plate 300 and out of the right fixed plate 102 and is fixed by bolts, so as to realize the sliding of the flat pressure plate 300 on the guide post assembly 400.
[0033] The drive mechanism 500 includes a screw 501 and a handwheel 502. One end of the screw 501 is connected to the center of the flat plate 300, and the other end is threaded to the right fixed plate 102 and extends out of the right fixed plate 102. The extended end is the bearing end to bear the external rotation driving force. The extended end is connected to the handwheel 502, and the movement of the flat plate 300 is driven by rotating the handwheel 502.
[0034] In this embodiment, the lithium battery assembly 200 includes three individual batteries 201, with the middle one being the central individual battery. The positive and negative terminals of the central individual battery are connected to the charging and discharging device. A temperature acquisition line is connected to the center of the top surface of the central individual battery, and a temperature acquisition line is connected to the center of the outer surface of the adjacent individual batteries on both sides. The above three temperature acquisition lines are externally connected to the temperature recorder 600.
[0035] The experimental apparatus for overcharge-triggered thermal runaway propagation of square lithium batteries in this embodiment has the following experimental procedure:
[0036] 1. Assembly stage:
[0037] Arrange the central unit and two side units (1-2 each) at intervals and insert the heat insulation board;
[0038] The array is placed between the left fixed plate and the flat pressure plate, and the handwheel is turned to apply a pressure of 15kN.
[0039] 2. Triggering Phase:
[0040] The central cell was overcharged with a constant current of 1C, and the temperature rise was monitored by thermocouples.
[0041] Thermal runaway is determined when the temperature rise rate is ≥3℃ / s, and charging is stopped.
[0042] 3. Diffusion observation:
[0043] Record the surface temperature changes of adjacent monomers for 1 hour;
[0044] If the temperature rise rate of adjacent monomers is ≥1℃ / s, thermal diffusion is determined to have occurred.
[0045] Working principle:
[0046] This invention provides a test device for overcharge-triggered thermal runaway propagation of square lithium batteries. Several (at least three) individual batteries are fully charged and arranged in a line perpendicular to the large surface of the battery. The positive and negative terminals of the middle battery are connected to the charging and discharging device. Heat insulation plates are attached between the individual batteries, with the heat insulation plates tightly fitted to adjacent individual batteries. Temperature acquisition lines are arranged at the center of the top surface of the middle battery and the center of the outer surface of the adjacent individual batteries. The lithium battery assembly is assembled between the left fixed plate and the flat pressure plate of the frame. Then, the handwheel is rotated, and the flat pressure plate is driven to move towards the lithium battery assembly via a screw, applying a certain binding force.
[0047] The intermediate cell was charged with constant current using the ratio of rated power to its nominal voltage. The process continued until three consecutive temperature rise rates of 3 degrees Celsius or higher were detected in the intermediate cell, or the cell caught fire or exploded. This was the criterion for thermal runaway. Charging was then stopped, and the cell was observed for 1 hour.
[0048] The criteria for determining thermal runaway are used to detect whether thermal runaway propagation occurs between two adjacent individual cells.
[0049] This utility model adopts a "screw pressure simulation + detachable heat insulation array" design, which solves a breakthrough problem:
[0050] (1) Low-cost replication of module working conditions: The four-guide pillar structure ensures uniform pressure distribution and simulates real restraint;
[0051] (2) Safety isolation mechanism: The heat insulation board can controllably block the heat transfer path;
[0052] (3) Standardized trigger judgment: central single cell overcharge + dual-sided temperature monitoring network.
[0053] The above are merely specific application examples of this utility model and do not constitute any limitation on the scope of protection of this utility model. All technical solutions formed by equivalent transformations or equivalent substitutions fall within the scope of protection of this utility model.
Claims
1. A test apparatus for overcharge-triggered thermal runaway propagation of square lithium batteries, characterized in that: It includes a frame (100), a lithium battery assembly (200), a flat pressure plate (300), a guide column assembly (400), and a drive mechanism (500). The frame (100) includes a base plate and a left fixing plate (101) and a right fixing plate (102) arranged parallel to each other at both ends of the base plate. The left fixing plate (101) and the right fixing plate (102) are respectively vertically arranged at the left and right ends of the base plate. A parallel planar pressure plate (300) is provided between the left fixed plate (101) and the right fixed plate (102). The planar pressure plate (300) is slidably disposed between the left fixed plate (101) and the right fixed plate (102) via a guide post assembly (400). The planar pressure plate (300) is driven by a driving mechanism (500). A lithium battery assembly (200) is provided between the flat plate (300) and the left fixed plate (101). The lithium battery assembly (200) includes no less than three individual cells (201). The individual cells (201) are arranged side by side, and a heat insulation plate (202) is provided between two adjacent individual cells (201). The heat insulation plate (202) is in close contact with the individual cells (201) on both sides.
2. The experimental apparatus for overcharge-triggered thermal runaway propagation of a square lithium battery according to claim 1, characterized in that: The guide post assembly (400) includes a first guide post (401), a second guide post (402), a third guide post (403), and a fourth guide post (404). The first guide post (401) and the fourth guide post (404) are symmetrically arranged at the bottom ends of the left fixing plate (101) and the right fixing plate (102), and the second guide post (402) and the third guide post (403) are symmetrically arranged at the top ends of the left fixing plate (101) and the right fixing plate (102).
3. The experimental apparatus for overcharge-triggered thermal runaway propagation of a square lithium battery according to claim 2, characterized in that: One end of the first guide post (401), the second guide post (402), the third guide post (403) and the fourth guide post (404) are fixed on the left fixed plate (101), and the other end passes through the flat pressure plate (300) and extends out of the right fixed plate (102) and is fixed by bolts, so as to realize the sliding of the flat pressure plate (300) on the guide post assembly (400).
4. The experimental apparatus for overcharge-triggered thermal runaway propagation of a square lithium battery according to claim 1, characterized in that: The drive mechanism (500) includes a screw (501) and a handwheel (502). One end of the screw (501) is connected to the center of the flat pressure plate (300), and the other end is threaded to the right fixed plate (102) and extends out of the right fixed plate (102). The extended end is the bearing end to bear the external rotation driving force.
5. The test apparatus for overcharge-triggered thermal runaway propagation of a square lithium battery according to claim 4, characterized in that: The protruding end of the screw (501) is connected to a handwheel (502), and the movement of the flat plate (300) is driven by rotating the handwheel (502).
6. The experimental apparatus for overcharge-triggered thermal runaway propagation of a square lithium battery according to claim 1, characterized in that: The lithium battery assembly (200) has a central single cell located in the middle, and the positive and negative electrodes of the central single cell are connected to the charging and discharging device. A temperature acquisition line is connected to the center of the top surface of the central single cell of the lithium battery assembly (200), and a temperature acquisition line is connected to the center of the outer surface of the single cells on both sides. Each temperature acquisition line is connected to a temperature recorder (600).