Battery detection device, battery module and battery system detection method

Abstract

The invention provides a battery detection device, a battery module and a battery system detection method. The battery detection device comprises a rigid part and a dependent variable detection part, the rigid part is suitable for being arranged on the battery cell module in a sleeving mode and attached to the outer wall face of the battery cell module, the rigid part is used for applying pre-tightening force to the battery cell module, the dependent variable detection part is connected to the side, away from the battery cell module, of the rigid part, and the dependent variable detection part is used for detecting the dependent variable of the rigid part. According to the battery detection device, a detection element does not need to be arranged in the battery cell module, damage to mechanical boundary conditions of the module is avoided, and test errors caused by damage to the mechanical boundary conditions of the battery cell module can be effectively avoided.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery detection device, a battery module and a battery system detection method. Background Art

[0002] During the production and use of batteries, the preload force of the battery cell module needs to be tested.

[0003] In the related art, detection is mainly achieved by placing a film or other types of pressure sensors between the battery cells, but this will change the mechanical boundary conditions of the module itself and cause certain test errors. Summary of the invention

[0004] The embodiments of the present application provide a battery detection device, a battery module and a battery system detection method, which can improve the technical problem of the preload force measurement error of the battery module.

[0005] In a first aspect, an embodiment of the present application provides a battery detection device, comprising:

[0006] A rigid member, suitable for being sleeved on the battery cell module and attached to the outer wall surface of the battery cell module, and the rigid member is used to apply a pre-tightening force to the battery cell module;

[0007] The strain detection component is connected to a side of the rigid component away from the battery cell module, and the strain detection component is used to detect the strain of the rigid component.

[0008] In one embodiment, the strain amount detection component includes a strain gauge, the strain gauge is attached to the outer wall surface of the rigid component, and the strain gauge is used to detect the strain amount of the rigid component.

[0009] In one embodiment, the strain amount detection member includes at least two strain gauges, and the at least two strain gauges are used to detect the strain amounts at different positions of the rigid member.

[0010] In one embodiment, at least two strain gauges are evenly distributed on the outer wall surface of the rigid component.

[0011] In one embodiment, the rigid part includes a first rigid part, a second rigid part, a third rigid part and a fourth rigid part connected in sequence, the first rigid part and the third rigid part are arranged opposite to each other and have the same length, the second rigid part and the fourth rigid part are arranged opposite to each other and have the same length, the length of the first rigid part is smaller than the length of the second rigid part, and the strain gauge is connected to the middle position of the second rigid part and / or the fourth rigid part.

[0012] In one embodiment, the strain amount detection member includes a control component and at least one of the following:

[0013] A capacitive sensor connected to the rigid member, the capacitive sensor being electrically connected to the control component, the control component being configured to determine the strain amount of the rigid member according to detection data of the capacitive sensor;

[0014] An electrostatic sensor is connected to the rigid part. The electrostatic sensor is electrically connected to the control component. The control component is configured to determine the strain amount of the rigid part according to detection data of the electrostatic sensor.

[0015] In one embodiment, along the height direction of the battery cell module, the ratio of the height of all the rigid parts to the height of the battery cell module is between 0.15 and 0.3.

[0016] In a second aspect, an embodiment of the present application provides a battery module, including a battery cell module and the above-mentioned battery detection device, wherein the rigid member is sleeved on the battery cell module.

[0017] In a third aspect, an embodiment of the present application provides a battery system detection method, wherein a rigid member is sleeved on the outer wall surface of the battery cell module, and the rigid member is used to apply a pre-tightening force to the battery cell module, and the battery system detection method includes:

[0018] Obtaining the stress of the rigid component;

[0019] Based on the stress of the rigid component, the state of the battery cell module and / or the preload force applied to the battery cell module are determined.

[0020] In one embodiment, the battery cell module includes a plurality of battery cells arranged in sequence, and at least two strain detection members are provided on a side of the rigid member away from the battery cell module, and the strain detection members are used to detect the strain of the rigid member. The step of determining the state of the battery cell module based on the stress of the rigid member includes:

[0021] Determining stresses at different positions of the rigid component based on detection data of at least two of the strain detection components;

[0022] Based on the stresses at different positions of the rigid component, the alignment states of the plurality of battery cells of the battery cell module are determined.

[0023] In one embodiment, the battery cell module comprises a plurality of battery cells arranged in sequence, the outer wall surface of the battery cell module is sleeved with at least two of the rigid members, a strain detection member is provided on the side of the rigid member away from the battery cell module, and the strain detection member is used to detect the strain of the rigid member;

[0024] The step of determining the state of the battery cell module based on the stress of the rigid component includes:

[0025] Determining stresses of different rigid parts based on the strains of different rigid parts;

[0026] Based on the stress of the different rigid components, the alignment state of the multiple cells of the cell module is determined.

[0027] In one embodiment, the step of determining the state of the battery cell module based on the stress of the rigid component includes:

[0028] Based on the current stress of the rigid part and a health status database, the health status of the battery cell module is determined, wherein the health status database includes the health status of the battery cell module corresponding to different stresses of the rigid part.

[0029] In one embodiment, the step of determining the state of the battery cell module based on the stress of the rigid component includes:

[0030] Based on the current stress of the rigid component and the reference value, determining whether the battery cell module is in a thermal runaway state;

[0031] The reference value is the stress of the rigid component when thermal runaway occurs in the battery cell module.

[0032] In one embodiment, the step of obtaining the stress of the rigid component comprises:

[0033] Obtaining the strain of the rigid component;

[0034] Based on the strain amount of the rigid member, the stress of the rigid member is determined.

[0035] In one embodiment, the step of obtaining the stress of the rigid component comprises:

[0036] Obtaining a shift of a resonance peak of the rigid member;

[0037] Based on the shift of the resonance peak of the rigid member, the stress of the rigid member is determined.

[0038] Beneficial effects of the embodiments of the present application:

[0039] In an embodiment of the present application, when the state of the battery cell module changes, the strain of the rigid part will also change due to the fit between the rigid part and the outer wall of the battery cell module. In other words, the state of the battery cell module is associated with the strain of the rigid part. The present application detects the strain of the rigid part through a strain detection part, and the state of the battery cell module can be determined according to the strain of the rigid part. The battery cell module can be detected without a large number of detection sensors, reducing the detection complexity and cost of the battery cell module. There is no need to set a detection element inside the battery cell module to avoid damage to the mechanical boundary conditions of the module itself, which can effectively avoid test errors caused by the destruction of the mechanical boundary conditions of the battery cell module. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 is a schematic diagram of the structure of a battery detection device provided in an embodiment of the present application, wherein a rigid member is sleeved on a battery cell module;

[0042] Figure 2 It is one of the top views of the battery detection device provided in the embodiment of the present application;

[0043] Figure 3 This is a second top view of the battery detection device provided in an embodiment of the present application;

[0044] Figure 4 is a schematic diagram of the structure of a battery detection device provided in an embodiment of the present application;

[0045] Figure 5 It is a flow chart of a battery system detection method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise stated, the directional words such as "upper" and "lower" used generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0047] Combine the following Figures 1 to 5 The present invention describes a battery detection device, a battery module and a battery system detection method.

[0048] According to the embodiment of the first aspect of the present application, Figure 1 and Figure 2 The battery detection device includes a rigid part 1 and a strain detection part 2. The rigid part 1 is suitable for being sleeved on the battery cell module 3 and attached to the outer wall surface of the battery cell module 3. The rigid part 1 is used to apply a pre-tightening force to the battery cell module 3. The strain detection part 2 is connected to the side of the rigid part 1 away from the battery cell module 3. The strain detection part 2 is used to detect the strain of the rigid part 1.

[0049] According to the battery detection device of the embodiment of the present application, the rigid part 1 is sleeved on the outer wall surface of the battery cell module 3, and the rigid part 1 applies a certain pre-tightening force to the battery cell module 3 to fix the battery cell module 3 and prevent the battery cell module 3 from being in a loose state. While the rigid part 1 applies the pre-tightening force to the battery cell module 3, the rigid part 1 will also generate corresponding stress, and the strain detection part 2 can detect the strain of the rigid part 1. Based on the strain, the stress of the rigid part 1 can be known, and then the pre-tightening force of the battery cell module 3 can be determined by the stress of the rigid part 1. That is to say, the present application detects the strain of the rigid part 1 through the strain detection part 2, determines the stress of the rigid part 1 through the strain, and determines the preload force of the battery module 3 according to the stress. The strain detection part 2 can be connected to the side of the rigid part 1 away from the battery module 3, and thus the preload force of the battery module 3 can be detected without placing a sensor between the battery cells of the battery module 3. The detection process will not destroy the mechanical boundary conditions of the battery module 3 itself, thereby ensuring the measurement accuracy of the preload force of the battery module 3.

[0050] In the related art, a method of placing a film or other type of pressure sensor between battery cells is usually adopted to implement the warning force test of the battery cell module 3. In addition to changing the mechanical boundary conditions of the module itself and causing certain test errors, the above method also requires the use of a large number of sensors, resulting in high detection costs. The strain detection member 2 of the present application detects the strain of the rigid member 1 and determines the preload force of the battery cell module 3 based on the strain. In addition to avoiding changes in the mechanical boundary conditions of the battery cell module 3 and ensuring measurement accuracy, it can also effectively reduce the number of detection elements used and reduce detection costs.

[0051] It is understandable that when the state of the battery cell module 3 changes, the strain of the rigid part 1 will also change due to the fit between the rigid part 1 and the outer wall of the battery cell module 3, that is, the state of the battery cell module 3 is associated with the strain of the rigid part 1. The present application detects the strain of the rigid part 1 through the strain detection part 2, and the state of the battery cell module 3 can be determined according to the strain of the rigid part 1, thereby realizing the detection of the battery cell module 3 without a large number of detection sensors, reducing the detection complexity and detection cost of the battery cell module 3. And there is no need to set a detection element inside the battery cell module 3 to avoid damage to the mechanical boundary conditions of the module itself, which can effectively avoid the test error caused by the destruction of the mechanical boundary conditions of the battery cell module 3.

[0052] Exemplarily, a mapping relationship between the state of the battery cell module 3 and the strain of the rigid component 1 may be established in advance. When the strain of the rigid component 1 is obtained, the state of the battery cell module 3 may be determined according to the mapping relationship.

[0053] It is also possible to first determine the stress of the rigid part 1 using the strain of the rigid part 1, and then determine the state of the battery module based on the stress of the rigid part 1. Specifically, when the state of the battery module 3 changes, the stress of the rigid part 1 will change accordingly, that is, the state of the battery module 3 can be determined by the stress of the rigid part 1. Then, the strain of the rigid part 1 can be detected by the strain detection part 2, and the stress of the rigid part 1 can be calculated based on the strain of the rigid part 1. The state of the battery module 3 can be determined by the stress of the rigid part 1.

[0054] In some examples, the rigid member 1 is, for example, a steel strip or an aluminum strip. It should be noted that the rigid member 1 is merely illustrated here and is not specifically limited to the rigid member 1.

[0055] In some examples, the strain of the rigid part 1 can be used to detect the health status of the battery cell module 3. For example, the internal expansion force of the battery cell module 3 will act on the rigid part 1, and the rigid part 1 will deform after being subjected to the force, that is, the strain of the rigid part 1 will change, and then the internal expansion force of the battery cell module 3 can be determined by detecting the strain of the rigid part 1, and then the health status of the battery cell module 3 can be determined according to the internal expansion force of the battery cell module 3, so as to realize the detection of the battery cell module 3.

[0056] The strain of the rigid part 1 can also be used to detect whether the multiple cells in the cell module 3 are neatly arranged. When the multiple cells of the cell module 3 are neatly arranged, the stress at different positions of the rigid part 1 is basically the same, that is, the strain at different positions of the rigid part 1 is basically the same. Then, by detecting the strain at different positions of the rigid part 1, it can be determined whether the multiple cells of the cell module 3 are neatly arranged.

[0057] The above is only an example of using the strain of the rigid part 1 to detect the state of the battery module 3. The strain of the rigid part 1 can be used to perform stress analysis on the battery module 3, that is, the strain of the rigid part 1 can also be used to detect other characteristics of the battery module 3.

[0058] In one embodiment of the present application, Figure 3 The strain amount detection component 2 includes a strain gauge 21 . The strain gauge 21 is attached to the outer wall surface of the rigid component 1 . The strain gauge 21 is used to detect the strain amount of the rigid component 1 .

[0059] It is understandable that the strain amount of the rigid component 1 can be detected by the strain gauge 21 so as to determine the stress of the rigid component 1 according to the strain amount, and further the preload force of the battery cell module 3 can be determined according to the stress of the rigid component 1 .

[0060] It should be noted that the state of the battery module can also be judged based on the stress of the rigid component 1, thereby realizing the detection of the state of the battery module.

[0061] In one embodiment of the present application, the strain amount detection member 2 includes at least two strain gauges 21 , and the at least two strain gauges 21 are used to detect the strain amounts at different positions of the rigid member 1 .

[0062] It can be understood that when the multiple cells of the cell module 3 are arranged neatly, the strain amounts at different positions of the rigid component 1 should be the same or the difference should be less than a threshold value.

[0063] At least two strain gauges 21 are connected to different positions of the rigid part 1 so that the at least two strain gauges 21 can detect the strain amounts at different positions of the rigid part 1. Then, based on the strain amounts at different positions of the rigid part 1, it can be determined whether the multiple battery cells of the battery cell module 3 are arranged neatly.

[0064] In some embodiments, at least two strain gauges 21 are evenly distributed on the outer wall surface of the rigid component 1 .

[0065] It can be understood that multiple strain gauges 21 can perform comprehensive detection on the strain amount of the rigid part 1, and can determine the preload force at different positions of the battery cell module 3 according to the strain amount at different positions of the rigid part 1, thereby realizing refined detection of the battery cell module 3. The strain amounts at different positions can also be combined to obtain a more accurate strain amount data that can represent the overall preload force of the battery cell module 3, thereby improving the detection accuracy of the preload force of the battery cell module 3.

[0066] In one embodiment of the present application, the strain gauge 21 extends along the width direction of the rigid component 1 , and the extension length of the strain gauge 21 is equal to the width of the rigid component 1 .

[0067] It can be understood that the length of the strain gauge 21 in the width direction of the rigid part 1 is set to be the same as the width of the rigid part 1, and then in the width direction of the rigid part 1, the strain gauge 21 can cover the rigid part 1, and the strain amount of the rigid part 1 can be effectively detected, thereby ensuring the accuracy of the detection.

[0068] In some examples, the extension length of the strain gauge 21 is equal to the width of the rigid component 1 , which can be understood as the edge of the orthographic projection of the strain gauge 21 on the rigid component 1 coincides with the length edge of the rigid component 1 .

[0069] In one embodiment of the present application, Figure 3 The rigid part 1 includes a first rigid part 11, a second rigid part 12, a third rigid part 13 and a fourth rigid part 14 which are connected in sequence. The first rigid part 11 and the third rigid part 13 are arranged opposite to each other and have the same length. The second rigid part 12 and the fourth rigid part 14 are arranged opposite to each other and have the same length. The length of the first rigid part 11 is smaller than that of the second rigid part 12. The strain gauge 21 is connected to the middle position of the second rigid part 12 and / or the fourth rigid part 14.

[0070] It can be understood that the first rigid part 11, the second rigid part 12, the third rigid part 13 and the fourth rigid part 14 are connected end to end to form the rigid part 1, and the first rigid part 11, the second rigid part 12, the third rigid part 13 and the fourth rigid part 14 are all in contact with the outer wall surface of the battery module 3. If the length of the second rigid part 12 and the fourth rigid part 14 is relatively long, the stress on the second rigid part 12 and the fourth rigid part 14 will be greater than the stress on the first rigid part 11 and the third rigid part 13, and then at the second rigid part 12 and the fourth rigid part 14, the deformation degree at the middle position of the second rigid part 12 and the fourth rigid part 14 is the largest, that is, the strain amount is the largest, and then the strain gauge 21 is set at the middle position of the second rigid part 12 and / or the fourth rigid part 14, which ensures the detection accuracy of the strain gauge 21.

[0071] It can be understood that a strain gauge 21 can be set at the middle position of the second rigid part 12 and the fourth rigid part 14 at the same time, so that two strain data can be obtained. The two test data can be used to verify each other. When the two test data differ too much, it means that one of the strain gauges 21 may have a problem and needs to be checked in time. The two test data can also be combined to obtain a more accurate strain value of the rigid part 1, thereby improving the detection accuracy.

[0072] In one embodiment of the present application, the strain detection member 2 includes a magnetic induction coil and two magnetic members arranged opposite to each other. The two magnetic members are both installed on the outer wall surface of the rigid member 1, and the magnetic induction coil is located between the two magnetic members.

[0073] It is understandable that a magnetic field can be formed between the two magnetic parts, and the magnetic induction coil can output corresponding induction data when it is between the two magnetic parts. The rigid part 1 will deform after being subjected to force, and the deformation of the rigid part 1 will cause the distance between the two magnetic parts to change, so that the magnetic flux passing through the magnetic induction coil changes, and the induction data of the magnetic induction coil will also change accordingly, and then the strain of the rigid part 1 can be determined through the induction data of the magnetic induction coil, so as to realize the detection of the strain of the rigid part 1.

[0074] In one embodiment of the present application, the strain detection component 2 includes a control component and a piezoelectric sheet. The piezoelectric sheet is attached to the rigid component 1. The piezoelectric sheet is electrically connected to the control component. The control component is configured to determine the strain of the rigid component 1 based on the voltage of the piezoelectric sheet.

[0075] It is understandable that when the rigid part 1 is deformed, the voltage of the piezoelectric sheet will also change. The piezoelectric sheet is electrically connected to the control component, and the control component can obtain the voltage data of the piezoelectric sheet, and then determine the strain of the rigid part 1 according to the voltage of the piezoelectric sheet.

[0076] In one embodiment of the present application, the strain amount detection member 2 includes a control component and a capacitive sensor, the capacitive sensor is connected to the rigid member 1, the capacitive sensor is electrically connected to the control component, and the control component is configured to determine the strain amount of the rigid member 1 according to the detection data of the capacitive sensor;

[0077] It is understandable that when the rigid part 1 is deformed, the detection data of the capacitive sensor will also change. The capacitive sensor is electrically connected to the control component, and the control component can obtain the detection data of the capacitive sensor, and then determine the strain of the rigid part 1 according to the detection data of the capacitive sensor.

[0078] In one embodiment of the present application, the strain detection component 2 includes a control component and an electrostatic sensor. The electrostatic sensor is connected to the rigid component 1. The electrostatic sensor is electrically connected to the control component. The control component is configured to determine the strain of the rigid component 1 based on the detection data of the electrostatic sensor.

[0079] It is understandable that when the rigid part 1 is deformed, the detection data of the electrostatic sensor will also change. The electrostatic sensor is electrically connected to the control component, and the control component can obtain the detection data of the electrostatic sensor, and then determine the strain of the rigid part 1 according to the detection data of the electrostatic sensor.

[0080] Exemplarily, the rigid component 1 includes a steel belt ring, which is sleeved on the battery cell module 3 .

[0081] In one embodiment of the present application, Figure 4 The battery detection device includes at least two rigid parts 1, and the at least two rigid parts 1 are sleeved on the battery module 3. The outer wall surface of each rigid part 1 is connected to the strain detection part 2.

[0082] It can be understood that each rigid part 1 is sleeved on the battery cell module 3, and the outer wall surface of each rigid part 1 is connected to the strain detection part 2, that is, the strain of each rigid part 1 can be detected, and then the preload force of the battery cell module 3 can be judged by the strain at each rigid part 1.

[0083] It is understandable that the rigid member 1 is attached to the outer wall surface of the cell module 3, that is, the rigid member 1 can play a role in fastening the cell module 3. By providing at least two rigid members 1 and both being sleeved on the cell module 3, the fastening effect on the cell module 3 is improved.

[0084] By providing a strain detection component 2 at each rigid part 1, the strain of each rigid part 1 can be detected. When the strain of each rigid part 1 is obtained, the states of different positions of the battery cell module 3 can be judged according to the positions of the strain detection components 2 of different rigid parts 1. The detection data of each strain detection component 2 can also be combined together to obtain more accurate strain data that can represent the overall preload force of the battery cell module 3, thereby improving the detection accuracy of the preload force of the battery cell module 3.

[0085] In some examples, when the state of the battery cell module 3 is normal, the strain quantities of different rigid parts 1 should be the same or the difference should be within the threshold. Then, the strain quantities of different rigid parts 1 are compared and calculated to determine whether some of the strain quantities have abnormal values. If so, the abnormal strain quantities can be eliminated to ensure the accuracy of the detection.

[0086] In one embodiment of the present application, the strain amount detection members 2 at two adjacent rigid members 1 are symmetrically distributed with respect to the symmetry plane of the two adjacent rigid members 1 .

[0087] It is understandable that after the rigid part 1 is sleeved on the battery module 3, the battery module 3 will be subjected to a certain preload force, and the rigid part 1 will have a certain stress. At this time, if the multiple batteries of the battery module 3 are neatly arranged, because the strain detection parts 2 at the two adjacent rigid parts 1 are symmetrical to each other, the stress at the position where the two adjacent rigid parts 1 are connected to the strain detection parts 2 should be the same, that is, the detection data of the strain detection parts 2 at the two adjacent rigid parts 1 should be the same, and then by determining whether the detection data of the strain detection parts 2 at the two adjacent rigid parts 1 are the same, it can be determined whether the multiple batteries of the battery module 3 are neatly arranged.

[0088] In some embodiments, along the height direction of the battery cell module 3 , the ratio of the height of all the rigid members 1 to the height of the battery cell module 3 is between 0.15 and 0.3.

[0089] It is understandable that if the ratio of the height of all rigid parts 1 to the height of the battery module 3 is less than 0.15, it is difficult for the rigid parts 1 to effectively fasten the battery module 3. If the ratio of the height of all rigid parts 1 to the height of the battery module 3 is greater than 0.3, the strain of the rigid parts 1 is less affected by the battery module 3, which is not conducive to the detection of the strain of the rigid parts 1, affects the detection accuracy of the strain detection part 2, and is not conducive to the detection of the preload or other states of the battery module 3 based on the strain of the rigid parts 1. Therefore, the present application sets the ratio of the height of the rigid parts 1 to the height of the battery module 3 to between 0.15 and 0.3.

[0090] According to an embodiment of the second aspect of the present application, the battery module includes a battery cell module 3 and the battery detection device of the above embodiment, and the rigid member 1 is sleeved on the battery cell module 3.

[0091] According to the battery of the embodiment of the present application, the rigid part 1 is sleeved on the outer wall surface of the battery cell module 3, and the rigid part 1 applies a certain pre-tightening force to the battery cell module 3 to fix the battery cell module 3 and prevent the battery cell module 3 from being in a loose state. While the rigid part 1 applies the pre-tightening force to the battery cell module 3, the rigid part 1 will also generate corresponding stress, and the strain detection part 2 can detect the strain of the rigid part 1, and the stress of the rigid part 1 can be known based on the strain, and then the pre-tightening force of the battery cell module 3 can be determined by the stress of the rigid part 1. That is to say, the present application detects the strain of the rigid part 1 through the strain detection part 2, determines the stress of the rigid part 1 through the strain, and determines the preload force of the battery module 3 according to the stress. The strain detection part 2 can be connected to the side of the rigid part 1 away from the battery module 3, and thus the preload force of the battery module 3 can be detected without placing a sensor between the battery cells of the battery module 3. The detection process will not destroy the mechanical boundary conditions of the battery module 3 itself, thereby ensuring the measurement accuracy of the preload force of the battery module 3 and the detection accuracy of the battery.

[0092] According to an embodiment of the third aspect of the present application, Figure 5 The outer wall of the battery cell module is provided with a rigid part, and the rigid part is used to apply a pre-tightening force to the battery cell module. The battery system detection method includes:

[0093] Step 101, obtaining the stress of the rigid component 1;

[0094] Exemplarily, the strain value represents the strain of the rigid part 1, and the strain of the rigid part 1 is associated with the stress of the rigid part 1, and the stress of the rigid part 1 can be determined according to the length change of the rigid part 1. In other words, the stress of the rigid part 1 can be calculated according to the strain of the rigid part 1. That is, the strain of the rigid part 1 can be detected by the strain detection part 2 to determine the stress of the rigid part 1 according to the strain.

[0095] Step 102: determining the state of the battery cell module 3 and / or the preload force applied to the battery cell module 3 based on the stress of the rigid component 1;

[0096] It can be understood that the rigid part 1 fits the battery cell module 3 , and the stress of the rigid part 1 is associated with the state of the battery cell module 3 , that is, the expansion force of the battery cell module 3 can be determined by analyzing the stress of the rigid part 1 .

[0097] It is understandable that after the rigid part 1 is sleeved on the battery module 3, the battery module 3 will be subjected to the preload force applied by the rigid part 1, and the rigid part 1 will also generate corresponding stress. Then, based on the stress of the rigid part 1, the preload force of the battery module 3 can be calculated.

[0098] In some examples, the stress of the rigid component 1 and the preload force of the battery cell module 3 may be in a linear relationship or a nonlinear relationship.

[0099] According to the battery system detection method of the embodiment of the present application, the state of the battery cell module 3 can be judged by the stress of the rigid part 1, and the detection of the battery cell module 3 can be achieved without a large number of detection sensors, thereby reducing the detection complexity and detection cost of the battery cell module 3.

[0100] In one embodiment of the present application, the battery cell module 3 includes a plurality of battery cells arranged in sequence, and at least two strain detection members 2 are provided on a side of the rigid member 1 away from the battery cell module 3, and the strain detection member 2 is used to detect the strain of the rigid member 1. Based on the stress of the rigid member 1, the step of determining the state of the battery cell module includes:

[0101] Determine stresses at different positions of the rigid component 1 based on detection data of at least two strain detection components 2;

[0102] Based on the stresses at different positions of the rigid component 1 , the alignment states of the multiple cells of the cell module 3 are determined.

[0103] It is understandable that different strain detection members 2 are used to detect the strain at different positions of the rigid member 1, and the stress of the rigid member can be determined based on the strain. When the multiple cells of the cell module 3 are arranged neatly, that is, the outer wall surfaces of the multiple cells are aligned, the stress at different positions of the rigid member 1 is basically the same, and by detecting the stress at different positions of the rigid member 1, it can be determined whether the multiple cells of the cell module 3 are arranged neatly.

[0104] In one embodiment of the present application, the battery cell module 3 includes a plurality of battery cells arranged in sequence, and at least two rigid members 1 are sleeved on the outer wall surface of the battery cell module 3. A strain detection member 2 is provided on the side of the rigid member 1 away from the battery cell module 3, and the strain detection member 2 is used to detect the strain of the rigid member 1;

[0105] Determine the stress of different rigid parts 1 based on the strain amounts of different rigid parts 1;

[0106] The step of determining the state of the battery module 3 based on the stress of the rigid component 1 includes:

[0107] Based on the stress of different rigid members 1 , the alignment state of the outer wall surfaces of the multiple battery cells of the battery cell module 3 is determined.

[0108] It can be understood that when the multiple battery cells of the battery cell module 3 are arranged neatly, that is, the outer wall surfaces of the multiple battery cells are aligned, the stresses of different rigid parts 1 are basically the same. Then, by detecting the strain amounts of different rigid parts 1, it can be determined whether the multiple battery cells of the battery cell module 3 are arranged neatly.

[0109] In one embodiment of the present application, the step of determining the state of the battery module 3 based on the stress of the rigid member 1 includes:

[0110] Based on the current stress of the rigid part 1 and the health status database, the health status of the battery cell module 3 is determined, wherein the health status database includes the health status of the battery cell module 3 corresponding to different stresses of the rigid part 1 .

[0111] It is understandable that when the cell module 3 is in different health states, the internal expansion force of the cell module 3 is different, and thus the stress of the rigid part 1 is also different. By obtaining the current stress of the rigid part 1 and comparing the current stress with the health database, the health state of the cell module 3 corresponding to the current stress of the rigid part 1 can be determined, thereby realizing the detection of the health state of the cell module 3.

[0112] In one embodiment of the present application, the step of determining the state of the battery module 3 based on the stress of the rigid member 1 includes:

[0113] Based on the current stress of the rigid component 1 and the reference value, determining whether the battery cell module 3 is in a thermal runaway state;

[0114] The reference value is the strain of the rigid component 1 when thermal runaway occurs in the battery cell module 3 .

[0115] It can be understood that by comparing the strain of the rigid part 1 with the reference value, when the strain of the rigid part 1 is the same as the reference value, it means that the battery cell module 3 is already in a thermal runaway state, and the power supply of the battery cell module 3 can be immediately cut off, thereby achieving early power off and increasing the safety performance of the battery cell module 3.

[0116] It is understandable that the reference value may be preset.

[0117] In one embodiment of the present application, the step of obtaining the stress of the rigid member includes:

[0118] Obtain the strain of the rigid part;

[0119] Based on the amount of strain in the rigid part, the stress in the rigid part is determined.

[0120] It is understandable that when the stress of the rigid part changes, the strain of the rigid part will also change, that is, the stress of the rigid part can be determined by the strain of the rigid part, and thus a more accurate stress of the rigid part can be obtained.

[0121] In one embodiment of the present application, the step of obtaining the stress of the rigid member includes:

[0122] Obtaining the shift of the resonance peak of the rigid member;

[0123] Based on the shift in the resonance peak of the rigid member, the stress of the rigid member is determined.

[0124] It is understandable that when the stress of the rigid part changes, the offset of the resonance peak of the rigid part will also change, and then the stress of the rigid part can be determined by the offset of the resonance peak of the rigid part, so that a more accurate stress of the rigid part can be obtained.

[0125] Exemplarily, when the offset of the resonance peak of the rigid part is obtained, the stress of the rigid part can be determined by the mapping relationship between the stress of the rigid part and the offset of the resonance peak of the rigid part. Specifically, the mapping relationship can be determined by setting a completely identical first battery cell module and a second battery cell module, setting a resonance detection component at the rigid part 1 at the first battery cell module, and setting a stress sensor at the rigid part 1 at the second battery cell module. The first battery cell module and the second battery cell module are completely identical, and then the offset of the resonance peak detected by the resonance detection component can be matched with the stress detected by the stress sensor. Then, the stress of the rigid part can be directly determined according to the offset of the resonance peak of the rigid part.

[0126] In one embodiment of the present application, before the step of obtaining the strain value of the rigid member 1, the method further includes:

[0127] The strain detection member 2 is mounted on the rigid member 1, and the detection value of the strain detection member 2 is set to 0;

[0128] Applying extrusion force to the battery cell module 3 to deform the battery cell module 3;

[0129] The rigid member 1 is sleeved on the battery cell module 3;

[0130] Stop applying the squeezing force to the battery cell module 3.

[0131] It is understandable that before the rigid part 1 is sleeved on the battery module 3, the detection value of the strain detection part 2 is reset to zero to ensure the accuracy of the subsequent detection data. Apply pressure to the battery module 3 to deform the battery module 3 so that the rigid part 1 can be smoothly and quickly sleeved on the battery module 3. After the rigid part 1 is sleeved on the battery module 3, stop applying the squeezing force to the battery module 3, the battery module 3 will restore the deformation and fit with the rigid part 1. At this time, the battery module 3 will be subjected to the pre-tightening force applied by the rigid part 1, and the rigid part 1 will also generate corresponding stress.

[0132] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A battery detection device, characterized in that: include: A rigid member, suitable for being sleeved on the battery cell module and attached to the outer wall surface of the battery cell module, and the rigid member is used to apply a pre-tightening force to the battery cell module; The strain detection component is connected to a side of the rigid component away from the battery cell module, and the strain detection component is used to detect the strain of the rigid component.

2. The battery detection device according to claim 1, characterized in that: The strain amount detection component includes a strain gauge, which is attached to the outer wall surface of the rigid component and is used to detect the strain amount of the rigid component.

3. The battery detection device according to claim 2, characterized in that: The strain amount detection component includes at least two strain gauges, and the at least two strain gauges are used to detect the strain amounts at different positions of the rigid component.

4. The battery detection device according to claim 3, characterized in that: At least two strain gauges are evenly distributed on the outer wall surface of the rigid component.

5. The battery detection device according to claim 2, characterized in that: The rigid part includes a first rigid part, a second rigid part, a third rigid part and a fourth rigid part connected in sequence, the first rigid part and the third rigid part are arranged opposite to each other and have the same length, the second rigid part and the fourth rigid part are arranged opposite to each other and have the same length, the length of the first rigid part is smaller than the length of the second rigid part, and the strain gauge is connected to the middle position of the second rigid part and / or the fourth rigid part.

6. The battery detection device according to claim 1, characterized in that: The strain detection component includes a control component and at least one of the following: A capacitive sensor connected to the rigid member, the capacitive sensor being electrically connected to the control component, the control component being configured to determine the strain amount of the rigid member according to detection data of the capacitive sensor; An electrostatic sensor is connected to the rigid part. The electrostatic sensor is electrically connected to the control component. The control component is configured to determine the strain amount of the rigid part according to detection data of the electrostatic sensor.

7. The battery testing device according to any one of claims 1 to 6, characterized in that: Along the height direction of the battery cell module, the ratio of the height of all the rigid parts to the height of the battery cell module is between 0.15 and 0.

3.

8. A battery module, characterized in that: It comprises a battery cell module and a battery detection device as claimed in any one of claims 1 to 7, wherein the rigid member is sleeved on the battery cell module.

9. A battery system detection method, characterized in that: The outer wall surface of the battery cell module is sleeved with a rigid member, and the rigid member is used to apply a pre-tightening force to the battery cell module. The battery system detection method includes: Obtaining the stress of the rigid component; Based on the stress of the rigid component, the state of the battery cell module and / or the preload force applied to the battery cell module are determined.

10. The battery system detection method according to claim 9, characterized in that: The battery cell module includes a plurality of battery cells arranged in sequence, at least two strain detection members are provided on a side of the rigid member away from the battery cell module, and the strain detection members are used to detect the strain of the rigid member. The step of determining the state of the battery cell module based on the stress of the rigid member includes: Determining stresses at different positions of the rigid component based on detection data of at least two of the strain detection components; Based on the stresses at different positions of the rigid component, the alignment states of the plurality of battery cells of the battery cell module are determined.

11. The battery system detection method according to claim 9, characterized in that: The battery cell module comprises a plurality of battery cells arranged in sequence, at least two of the rigid members are sleeved on the outer wall of the battery cell module, a strain detection member is provided on the side of the rigid member away from the battery cell module, and the strain detection member is used to detect the strain of the rigid member; The step of determining the state of the battery cell module based on the stress of the rigid component includes: Determining stresses of different rigid parts based on the strains of different rigid parts; Based on the stress of the different rigid components, the alignment state of the multiple cells of the cell module is determined.

12. The battery system detection method according to claim 9, characterized in that: The step of determining the state of the battery cell module based on the stress of the rigid component includes: Based on the current stress of the rigid part and a health status database, the health status of the battery cell module is determined, wherein the health status database includes the health status of the battery cell module corresponding to different stresses of the rigid part.

13. The battery system detection method according to claim 9, characterized in that: The step of determining the state of the battery cell module based on the stress of the rigid component includes: Based on the current stress of the rigid component and the reference value, determining whether the battery cell module is in a thermal runaway state; The reference value is the stress of the rigid component when thermal runaway occurs in the battery cell module.

14. The battery system detection method according to any one of claims 9 to 13, characterized in that: The step of obtaining the stress of the rigid component comprises: Obtaining the strain of the rigid component; Based on the strain amount of the rigid member, the stress of the rigid member is determined.

15. The battery system detection method according to any one of claims 9 to 13, characterized in that: The step of obtaining the stress of the rigid component comprises: Obtaining a shift of a resonance peak of the rigid member; Based on the shift of the resonance peak of the rigid member, the stress of the rigid member is determined.

Images