A battery swelling detection method

Abstract

This invention relates to the field of battery safety testing technology, specifically a battery expansion detection method, comprising the following steps: designing conductive printing paths on a first surface of a printing carrier; printing conductive ink along the conductive printing paths onto the printing carrier; curing the conductive ink to form a sensing circuit; attaching the second surface of the printed carrier to the surface of the battery cell; connecting the first detection connection point of the sensing circuit to the second detection connection point of a monitoring host, the monitoring host monitoring the resistance value of the sensing circuit, and when the resistance value of the sensing circuit increases, it indicates that the battery cell has expanded. This method is less affected by environmental factors such as vibration, impact, and electromagnetic interference, reducing false detections. Furthermore, this application provides more sensitive detection, achieving expansion judgment through monitoring circuit resistance changes, which is more intuitive and reliable.

Description

Technical Field

[0001] This invention relates to the field of battery safety testing technology, specifically a method for detecting battery swelling. Background Technology

[0002] With the development of battery technology, increasing battery capacity is a critical requirement. The rapid adoption of silicon-doped batteries and the increase in silicon doping levels have brought certain risks to battery safety, particularly the risk of expansion in silicon-doped batteries. Current technologies often use pressure sensors or pressure detection patches to detect battery expansion. However, this method has some drawbacks. Pressure sensors are prone to fatigue failure under repeated stress and fatigue loads, affecting their lifespan. Furthermore, this method is susceptible to false detections when exposed to environmental factors such as vibration, impact, and electromagnetic interference.

[0003] Therefore, there is an urgent need to provide a battery swelling detection method to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a battery swelling detection method to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides a battery swelling detection method, comprising the following steps: S1.1 Design conductive printing paths on the first surface of the printing carrier, where the first surface is one of the surfaces of the printing carrier along the thickness direction; S2.1 Print conductive ink onto the first surface along the conductive printing path; S2.2, Curing conductive ink to form sensing circuitry; S3.1. Attach the second side of the printed carrier after printing to the surface of the battery cell. The second side is the other surface of the printed carrier relative to the first side along the thickness direction. S4.1 Connect the first detection connection point of the sensing line to the second detection connection point of the monitoring host. The monitoring host monitors the resistance value of the sensing line. When the resistance value of the sensing line increases, it indicates that the battery cell has expanded.

[0006] Furthermore, the methods for monitoring the resistance of the sensing circuit by the monitoring host include real-time monitoring and periodic monitoring: Real-time monitoring continuously monitors the resistance of the sensing circuit through the monitoring host; Periodic monitoring involves the monitoring host monitoring the resistance of the sensing circuit according to a preset cycle.

[0007] Furthermore, the conductive printed lines can be either circular or cross-shaped.

[0008] Furthermore, the line width of the sensing circuit is 0.1-1mm.

[0009] Furthermore, the printing method in step S2.1 is one of 3D printing, inkjet technology, or dispensing.

[0010] Furthermore, in step S2.2, the ink is cured using either UV curing or temperature curing.

[0011] Furthermore, the number of the first detection connection point and the second detection connection point is at least two.

[0012] Furthermore, the printing medium can be either battery adhesive paper or battery cell protective film.

[0013] Furthermore, when the monitoring host detects that the resistance of the sensing circuit has increased, the monitoring host performs one of the following operations: controlling the current and voltage of the power circuit or controlling the disconnection of the power circuit.

[0014] The above technical solution produces the following technical effects: 1) This application designs and prints a cured conductive ink on a printing carrier to form a sensing circuit, which is then attached to the surface of the battery cell. Expansion is detected by changes in the resistance of the sensing circuit. Compared to pressure sensors, the sensing circuit of this application has no sensitive components prone to fatigue failure, thus avoiding failure problems under repeated stress and fatigue loads and extending service life. Furthermore, the detection method based on resistance changes in this application is less affected by environmental factors such as vibration, impact, and electromagnetic interference, reducing the possibility of false detections.

[0015] 2) The sensing circuit structure formed by conductive ink printing in this application is simple and low in cost. The flexible printing carrier can be closely attached to the surface of the battery cell, making the detection more sensitive. The expansion judgment is achieved by monitoring the change of circuit resistance, which is more intuitive and reliable. Attached Figure Description

[0016] Figure 1 This is a schematic diagram showing the connection between the sensing circuit and the monitoring host of the present invention. Figure 2 This is a schematic diagram of the cross-shaped induction circuit of the present invention distributed on the front of the battery; Figure 3 This is a schematic diagram showing the cross-shaped induction circuitry of the present invention distributed on the front of the battery and the cabin surface; Figure 4 This is a schematic diagram showing the circular induction circuit of the present invention distributed on the front of the battery; Tag name: 1-Sensing circuit; 11-First detection connection point; 12-Second detection connection point; 2-Front side; 3-Nacelle surface; 4-Monitoring host. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0018] Existing technologies for monitoring battery expansion often use pressure sensors or pressure detection patches to detect battery expansion pressure. However, in this detection method, the sensitive element of the pressure sensor is prone to fatigue failure under repeated stress and fatigue loads, which affects its service life. Furthermore, this method is prone to false detections when affected by environmental factors such as vibration, impact, and electromagnetic interference.

[0019] Therefore, the present invention provides a battery swelling detection method to solve the above problems, specifically including the following steps: S1.1 Conductive printing lines are designed on the first surface of the printing carrier, where the first surface is one of the surfaces of the printing carrier along its thickness direction. Preferably, the printing carrier is a protective film wrapped around the surface of the battery cell, or commonly used battery adhesive paper, such as PET adhesive paper, Mylar adhesive paper, PC adhesive paper, PVC adhesive paper, etc. These adhesive papers have excellent insulation properties, effectively isolating the conductive lines from the battery cell, avoiding short-circuit risks, ensuring battery safety, stably supporting the conductive printing lines, preventing line breakage or detachment, and improving structural reliability. For more preferred embodiments, please refer to further details. Figure 2 , 4 The conductive printing path can be circular, cross-shaped, or other shapes. A cross-shaped sensing path can expand the sensing range, while a circular path can achieve uniform circumferential sensing. The conductive printing path can be distributed across the printing substrate as needed to improve space utilization and sensing coverage. Furthermore, the width of sensing path 1 is 0.1-1mm. This design balances conductivity and space efficiency, facilitating miniaturization and thinner designs while saving material costs.

[0020] S2.1. Conductive ink is printed onto the first surface of the printing carrier along the conductive printing path. Preferably, the printing method is one of 3D printing, inkjet technology, or dispensing. 3D printing offers high forming precision and design freedom; inkjet technology can print fine conductive lines and is compatible with various printing carriers; dispensing allows for precise control of the amount of adhesive, forming a thicker conductive layer, and is easy to operate.

[0021] S2.2 Curing conductive ink to form sensing circuit 1, preferably, the ink is cured by either UV curing or temperature curing.

[0022] S3.1. Attach the second side of the printed carrier after printing to the surface of the battery cell. The second side is the other surface of the printed carrier relative to the first side along the thickness direction. S4.1 Connect the first detection connection point 11 of the induction line 1 to the second detection connection point 12 of the monitoring host 4. Preferably, the number of the first detection connection point 11 and the second detection connection point 12 is at least two. The monitoring host 4 monitors the resistance value of the induction line 1. When the resistance value of the induction line 1 increases, it indicates that the battery cell has expanded. Furthermore, the monitoring host 4 monitors the resistance value of the induction line 1 using both real-time monitoring and periodic monitoring methods. Real-time monitoring continuously monitors the resistance value of the sensing line 1 through the monitoring host 4; Periodic monitoring involves the monitoring host 4 monitoring the resistance of the sensing line 1 according to a preset period. This preset period can be a fixed time, such as 24 hours, or it can be set to one charge-discharge cycle. By monitoring the resistance changes of the sensing line 1, cell expansion can be effectively monitored. Real-time monitoring continuously monitors resistance changes to detect cell expansion in real time, while periodic monitoring periodically detects resistance changes to periodically detect cell expansion, ensuring safe use of the cells.

[0023] Furthermore, when the monitoring host 4 detects an increase in the resistance of the sensing line 1, it performs one of the following operations: controlling the power circuit or cutting off the power circuit. This involves limiting the current or reducing the voltage of the power circuit to prevent Joule heat buildup at high-resistance locations, thus avoiding circuit burning and insulation damage. Alternatively, directly cutting off the power supply circuit can prevent the fault from worsening at its source, thereby preventing safety accidents caused by the increased resistance of the sensing line 1 and protecting the electrical equipment. Example 2

[0024] Please refer to Figure 2-4 This embodiment provides an application example of the method of this application on a battery with a PET coating film: Conductive printing paths are designed on the first surface of the printing carrier, and then conductive ink is printed and cured along the conductive printing paths to obtain the sensing line 1. This embodiment provides three bonding schemes for the printing carrier: 1) such as Figure 2 The second side of the printing carrier is attached to the front side of the battery. The sensing line 1 is cross-shaped, and the first detection connection point 11 is located on the front side 2 of the battery. The battery's housing surface 3 and the front side 2 are two opposite surfaces along the battery thickness direction.

[0025] 2) such as Figure 3 The second side of the printing carrier is attached to the battery's housing surface and front side. The sensing line 1 is cross-shaped, and the first detection connection point 11 is located on the battery's housing surface 3.

[0026] 3) such as Figure 4 The second side of the printing carrier is attached to the front side of the battery. The sensing circuit 1 is in the shape of a ring, and the first detection connection point 11 is located on the front side 2 of the battery.

[0027] The above three solutions achieve the function of detecting cell expansion while significantly reducing the amount of conductive ink used, further saving consumable costs.

[0028] The principle by which this invention achieves the corresponding technical effects is as follows: When the battery cell expands, the printed substrate attached to the cell surface is stretched along with it, causing the induction circuitry on the first surface of the printed substrate to be elongated and its cross-sectional area to decrease. According to the resistance formula... Let R be the resistivity, L be the line length, and S be the cross-sectional area. When L increases and S decreases, R increases. Therefore, the monitoring host can determine that the battery cell has expanded by detecting the increase in the resistance of the sensing line. Compared with the pressure sensor used in traditional battery expansion detection methods, the sensing line of this application has no sensitive elements that are prone to fatigue failure, which can avoid failure problems under repeated stress and fatigue loads, and can significantly extend the service life. Moreover, the monitoring of the resistance change of the sensing line 1 in this application can effectively realize the real-time monitoring of battery cell expansion, further ensuring the safety of battery cell use.

[0029] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for detecting battery swelling, characterized in that, Includes the following steps: S1.

1. Conductive printing paths are designed on the first surface of the printing carrier, where the first surface is one of the surfaces of the printing carrier along the thickness direction; S2.

1. Print conductive ink onto the first surface along the conductive printing path; S2.

2. Curing the conductive ink to form a sensing circuit; S3.

1. The second side of the printed carrier after printing is attached to the surface of the battery cell. The second side is the other surface of the printed carrier relative to the first side along the thickness direction. S4.1 Connect the first detection connection point of the sensing line to the second detection connection point of the monitoring host. The monitoring host monitors the resistance value of the sensing line. When the resistance value of the sensing line increases, it indicates that the battery cell has expanded.

2. The battery expansion detection method according to claim 1, characterized in that, The method by which the monitoring host monitors the resistance value of the sensing line includes real-time monitoring and periodic monitoring: The real-time monitoring continuously monitors the resistance value of the sensing line through the monitoring host. The periodic monitoring involves the monitoring host detecting the resistance value of the sensing circuit according to a preset cycle.

3. The battery expansion detection method according to claim 1, characterized in that, The conductive printed path can be either a circular or a cross shape.

4. The battery swelling detection method according to claim 1, characterized in that, The width of the sensing circuit is 0.1-1mm.

5. The battery expansion detection method according to claim 1, characterized in that, The printing method in step S2.1 is one of 3D printing, inkjet technology, or dispensing.

6. The battery swelling detection method according to claim 1, characterized in that, In step S2.2, the ink is cured using either UV curing or temperature curing.

7. The battery expansion detection method according to claim 1, characterized in that, The number of the first detection connection point and the second detection connection point is at least two.

8. The battery swelling detection method according to claim 1, characterized in that, The printing carrier is either battery adhesive paper or battery cell protective film.

9. The battery expansion detection method according to claim 1, characterized in that, When the monitoring host detects that the resistance of the sensing line has increased, the monitoring host performs one of the following operations: controlling the current and voltage of the power circuit, or controlling the disconnection of the power circuit.

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