Battery cell life prediction method and device based on safety valve and computer equipment

Abstract

The invention relates to the technical field of batteries, and discloses a battery cell life prediction method and device based on a safety valve, computer equipment and a storage medium, and a battery cell comprises an electrochemical battery cell body reflecting a battery cell chemical material, the safety valve and a strain gauge pasted on the surface of the safety valve. Determining the number of deformation times of the safety valve during charging or discharging of the battery cell; and determining the service life of the battery cell based on the deformation times of the safety valve. Through the technical scheme of the invention, the problem of how to accurately predict the service life of the battery cell through the safety valve of the battery cell is solved, and accurate prediction of the service life of the battery cell based on the safety valve is realized.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a method, device, computer equipment and storage medium for predicting battery cell life. Background Art

[0002] During the use of battery cells, an issue that cannot be ignored is the reliability of structural parts. The life of battery cells is affected by the life of the battery cell system and the life of structural parts. As the life of the battery cell system becomes longer and longer, the reliability requirements for structural parts are also getting higher and higher. Therefore, while pursuing the life of the battery cell system, the long life of structural parts cannot be ignored. For example, the safety valve in the structure. After the safety valve fails, the electrolyte inside the battery cell overflows and corrodes the module or other battery cells in the battery pack. In special cases, the module or battery pack has poor contact, and the sparks that appear can easily ignite the organic electrolyte, causing a fire and causing safety problems.

[0003] The safety valves of battery cells have different service lives due to factors such as material differences and processing accuracy, which in turn affects the life of the battery cells.

[0004] In related technologies, how to accurately predict the life of a battery cell by combining the safety valve of the battery cell has become an urgent problem to be solved. Summary of the Invention

[0005] In view of this, the present invention provides a method, apparatus, computer device and storage medium for predicting battery cell life to solve the problem of low accuracy in battery cell life prediction while ensuring that there are fewer sensing devices inside the battery module.

[0006] In a first aspect, the present invention provides a method for predicting the life of a battery cell based on a safety valve. The battery cell includes an electrochemical cell body reflecting the chemical material of the battery cell, a safety valve, and a strain gauge attached to the surface of the safety valve. The method includes:

[0007] According to the change of the electrical signal of the strain gauge, the number of times the safety valve is deformed when the battery cell is charging or discharging is determined;

[0008] The service life of the battery cell is determined based on the number of deformations of the safety valve.

[0009] In some optional embodiments, determining the deformation amount of the safety valve generated when the battery cell is charging or discharging based on the change in the electrical signal of the strain gauge includes:

[0010] Obtain the change in electrical signal of the strain gauge;

[0011] The number of deformations of the safety valve corresponding to the electrical signal change is determined using a preset electrical signal change and deformation number lookup table, which indicates a one-to-one correspondence between multiple preset electrical signal changes and multiple safety valve deformation numbers.

[0012] In some optional embodiments, determining the service life of the battery cell based on the number of deformations of the safety valve includes:

[0013] Determine the service life of the safety valve according to the number of deformations of the safety valve;

[0014] The service life of the battery cell is determined based on the service life of the safety valve and the service life of the electrochemical cell body.

[0015] In some optional implementations, determining the service life of the safety valve according to the number of deformations of the safety valve includes:

[0016] According to the number of deformations of the safety valve, the service life of the safety valve corresponding to the number of deformations of the safety valve is determined from the deformation life curve, wherein the deformation life curve indicates a mapping relationship between the number of deformations of the safety valve and the service life of the safety valve.

[0017] In some optional embodiments, before determining the service life of the safety valve corresponding to the number of deformations of the safety valve from the deformation life curve according to the number of deformations of the safety valve, the method further includes:

[0018] The deformation times of the sample safety valve and the usable times of the sample safety valve are collected and combined as sample coordinates. The usable times of the sample safety valve indicate the service life of the sample safety valve.

[0019] All collected sample coordinates are fitted, and the fitted curve is obtained as the deformation life curve of the safety valve's deformation times and service life.

[0020] In some optional embodiments, determining the service life of the cell according to the service life of the safety valve and the service life of the electrochemical cell body includes:

[0021] When the service life of the safety valve is less than the service life of the electrochemical cell body, the service life of the cell is determined based on the time when the safety valve fails;

[0022] When the service life of the safety valve is greater than the service life of the electrochemical cell body, the service life of the electrochemical cell body shall be taken as the service life of the cell;

[0023] When the service life of the safety valve is equal to the service life of the electrochemical cell body, the service life of the safety valve or the service life of the electrochemical cell body is taken as the service life of the cell.

[0024] In a second aspect, the present invention provides a battery cell life prediction device based on a safety valve. The battery cell includes an electrochemical cell body reflecting the chemical material of the battery cell, a safety valve, and a strain gauge attached to the surface of the safety valve. The device includes:

[0025] A deformation determination module is used to determine the number of deformations of the safety valve generated when the battery cell is charging or discharging based on the change in the electrical signal of the strain gauge;

[0026] The service life determination module is used to determine the service life of the battery cell based on the number of deformations of the safety valve.

[0027] In a third aspect, the present invention provides a computer device comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the safety valve-based cell life prediction method of the above-mentioned first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0028] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the safety valve-based cell life prediction method of the above-mentioned first aspect or any corresponding embodiment thereof.

[0029] In a fifth aspect, the present invention provides a computer program product comprising computer instructions for causing a computer to execute the safety valve-based cell life prediction method of the first aspect or any corresponding embodiment thereof.

[0030] The safety valve-based battery cell life prediction method provided by the present invention achieves the following beneficial technical effects: By using a strain gauge attached to the surface of the safety valve, the number of times the safety valve contracts and expands is obtained to reflect the service life of the safety valve. The service life of the battery cell is also determined in combination with the life of the electrochemical cell body, which reflects the chemical material of the battery cell. The service life of the battery cell is indirectly determined by predicting the service life of the safety valve and the life of the electrochemical cell body. Among them, the number of times the safety valve deforms when the battery cell is charging or discharging is determined based on the change in the electrical signal of the strain gauge, which helps to determine the service life of the safety valve. The service life of the battery cell is determined based on the number of deformations of the safety valve. Accurate prediction of the battery cell life based on the safety valve is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 is a schematic diagram of a battery cell according to an embodiment of the present invention;

[0033] Figure 2is a flow chart of a method for predicting the life of a battery cell based on a safety valve according to an embodiment of the present invention;

[0034] Figure 3 is a schematic diagram of a safety valve according to an embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram of a safety valve according to an embodiment of the present invention during charging and discharging of a battery cell;

[0036] Figure 5 is a schematic diagram of a battery module according to an embodiment of the present invention;

[0037] Figure 6 A partial schematic diagram of a battery module according to an embodiment of the present invention;

[0038] Figure 7 This is a flow chart of determining the deformation of a safety valve according to the variation of an electrical signal of a strain gauge according to an embodiment of the present invention;

[0039] Figure 8 This is a flow chart of determining the service life of a battery cell based on the number of deformations of a safety valve according to an embodiment of the present invention;

[0040] Figure 9 A schematic diagram of a process for determining the service life of a battery cell according to an embodiment of the present invention;

[0041] Figure 10 is a structural block diagram of a battery cell life prediction device based on a safety valve according to an embodiment of the present invention;

[0042] Figure 11 is a structural diagram of a computer device provided by an optional embodiment of the present invention;

[0043] Reference numerals:

[0044] 10: Positive pole; 11: Negative pole; 12: Safety valve; 13: Strain gauge; 14: Front of battery cell; 15: Side of battery cell; 51: Battery cell; 52: Bar; 53: Long bolt; 54a: End plate A; 54b: End plate B; 55: Cable tie; 56: Main lead; 61a: Lead A; 61b: Lead B. DETAILED DESCRIPTION

[0045] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0046] Amidst the rapid development of new energy vehicles, consumer electronics, and energy storage systems, demand for battery cells, a key component, is exploding, and the industry is evolving rapidly. Improving energy density, extending cycle life, enhancing safety, enabling fast charging, and meeting environmental protection requirements have become the primary development directions for battery cell technology.

[0047] During the life of battery cells, a key concern is the reliability of structural components. The life of a battery cell is affected by the life of both the cell system and the structural components. As the life of the cell system increases, the reliability requirements for the structural components also become increasingly stringent. Therefore, while pursuing the longevity of the cell system, the long life of the structural components cannot be ignored. For example, if the safety valve in a structural component fails, the electrolyte inside the cell will overflow, corroding the module or other cells in the battery. In extreme cases, if the module or battery contacts poorly, the resulting sparks can easily ignite organic electrolyte, causing a fire and posing a safety hazard. Therefore, in addition to monitoring the performance, voltage, and temperature of the battery cell, the life of the safety valve can also pose a safety concern and should not be ignored. When a battery cell is overcharged, overheated, or has an internal short circuit, a large amount of gas will be generated inside. When the pressure rises to a certain level, the explosion-proof valve will open, releasing the high-pressure gas inside and preventing the risk of explosion of the battery cell due to excessive pressure. However, the residual marks on the safety valve are formed by die stamping or laser etching, and their thickness will fluctuate, resulting in different fatigue life of the safety valve (breathing valve); due to factors such as material uniformity and deformation strengthening, the fatigue life of the safety valve is also different.

[0048] When the fatigue life of the safety valve is shorter than the service life of the battery cell system, or the safety valve is defective (not detected in a short time during the production process), if the battery cell is used for a period of time and a through crack occurs in the safety valve notch, the internal electrolyte will overflow or evaporate, corroding the surrounding battery cells and causing serious damage to the module and battery pack.

[0049] In order to increase the service life of the safety valve, high requirements are usually placed on the uniformity of raw materials, dimensional accuracy of forming and mechanical properties after forming to ensure that the safety valve works normally throughout the entire service life of the battery cell.

[0050] However, the uniformity of raw materials, the dimensional accuracy of forming, and the mechanical properties after forming will all fluctuate within a certain range. If the safety valve after forming has no through cracks or is slightly damaged or corroded, it will be difficult to detect in a short period of time during mass production and assembly. However, if the safety valve fails abnormally during the use of the battery cell, it may affect the failure of adjacent battery cells, the entire mold, or the battery. Therefore, monitoring the status of the safety valve to predict the service life of the battery cell has become an urgent problem to be solved.

[0051] Figure 1 Schematic diagram of the battery cell according to an embodiment of the present invention. Figure 1As shown, the cell structure is a cube. A cube structure includes a rectangular parallelepiped structure and a square structure. When the cell structure is a rectangular parallelepiped structure, the top of the cell is provided with a positive electrode column 10, a negative electrode column 11, a safety valve 12, and a strain gauge 13. Of the four exterior surfaces, excluding the top and bottom, the surface with the largest area is the front surface 14, and the surface with the smallest area is the side surface 15. The interior of the cell contains the electrochemical cell body, which reflects the cell's chemical materials, including but not limited to lithium iron phosphate (LiFePO4, LFP) and nickel-cobalt-manganese ternary batteries. In one example of this embodiment, the strain gauge is attached to the geometric center of the exterior surface of the safety valve, i.e., the side in contact with air. The strain gauge can be a metal strain gauge or a semiconductor strain gauge, with a metal strain gauge being preferred. The strain gauge dimensions are: the sensitive gate length L is between 5 and 25 mm, and the width b is between 1 and 5 mm, preferably L is between 10 and 25 mm, and the width b is between 3 and 5 mm. Strain gauge resistance: Resistance range: 120-2000Ω, preferably 1000-2000Ω. Strain gauge operating temperature: -30°C to +70°C. Strain gauge strain range: ±0.1% to ±30%, preferably ±0.5% to ±15%.

[0052] According to an embodiment of the present invention, an embodiment of a method for predicting the life of a battery cell based on a safety valve is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0053] In this embodiment, a method for predicting the life of a battery cell based on a safety valve is provided, which can be used for a battery control device of a battery module. Figure 2 FIG. 1 is a flow chart of a method for predicting the life of a battery cell based on a safety valve according to an embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0054] Step S201: determining the number of deformations of the safety valve during charging or discharging of the battery cell based on the variation of the electrical signal of the strain gauge.

[0055] In this embodiment, the electrical signal change refers to the value converted by the strain gauge into an electrical signal change by detecting changes in tension due to expansion and contraction of the safety valve surface. Optionally, the electrical signal can be represented by current, resistance, or other factors. Preferably, the resistance change is determined to determine whether it exceeds a resistance threshold (corresponding to a slight concavity or convexity on the safety valve surface).

[0056] Figure 3 Schematic diagram of a safety valve according to an embodiment of the present invention. Figure 3As shown, the safety valve is elliptical in shape. Along the long axis (cross section BB), the outermost ring is 31.68 mm long, and along the short axis (cross section AA), the outermost ring is 19.68 mm wide. The outer edge region forms the base of the safety valve, which is generally 0.45 to 0.55 mm thick. The ring closest to the center of the safety valve is an elliptical shape formed by a residual score. Along the long axis (cross section BB), the outermost ring is 28.05 to 29.05 mm long, and the outermost distance from the score is 26.9 to 27.5 mm. Along the short axis (cross section AA), the outermost ring is 16.05 to 17.05 mm wide, and the outermost distance from the score is 14.6 to 15.2 mm. The thickness of this residual score is generally 0.1 to 0.3 mm.

[0057] Figure 4 Schematic diagram of a safety valve in an embodiment of the present invention during charging and discharging of a battery cell. Figure 4 As shown in the figure, in its initial state, or when assembled into a battery cell, the surface of the safety valve appears slightly convex or flat. During charging, the internal material of the battery cell expands, increasing the internal air pressure, causing the safety valve to convex outward. This stretches the resistance wire in the strain gauge, reducing its cross-sectional area and increasing the resistance. During discharge, the internal material of the battery cell contracts, decreasing the internal air pressure, causing the safety valve to return to its slightly convex or flat state. This shortens the resistance wire in the strain gauge, increasing its cross-sectional area and decreasing the resistance. If the internal air pressure continues to decrease, the safety valve becomes slightly concave, stretching the resistance wire and reducing its cross-sectional area, increasing the resistance. Therefore, the deformation of the safety valve during charging and discharging can be measured using the electrical signal from the strain gauge. For example, based on the change in resistance, whether it is greater than the resistance threshold (the resistance threshold when slightly convex or the resistance threshold when slightly concave), it is determined whether the safety valve has failed; and whether the stability of the resistance meets the process capability index (Complex Process Capability Index, CPK) value of 1.33, and the preferred CPK value is 1.67. The deformation of the safety valve under the action of air pressure can be indirectly known, thereby predicting the fatigue service life of the safety valve, and then predicting the life of the battery cell.

[0058] In one example of this embodiment, when the battery cell is charging, lithium ions are released from the LFP, and the volume of the LFP shrinks by 4% to 7%. When the lithium ions are embedded in the graphite, especially in the middle and late stages of charging, a large number of lithium ions are embedded in the graphite, causing the volume of the graphite to expand by 8% to 25%. The volume shrinkage of the LFP is less than the volume expansion of the graphite, which will cause the electrolyte level in the battery cell to rise, causing the air pressure in the battery cell to increase, and the safety valve to bulge outward.

[0059] When the battery cell is discharged, lithium ions are released from graphite and transferred to LFP. The volume of graphite shrinks and the volume of LFP expands, but the volume expansion of LFP is less than the volume contraction of graphite, so the electrolyte level drops, the air pressure decreases, and the safety valve recovers inward.

[0060] Because the total number of deformations of a safety valve depends on its material, and the number of deformations the material can withstand determines the number of deformations the safety valve can undergo, the number of deformations can be used to reflect the safety valve's service life. The present invention indirectly reflects the safety valve's deformation using strain gauges. Specifically, the strain gauges capture the electrical signal representation of the tension generated by the expansion and contraction of the safety valve, and the change in the electrical signal is used to determine the safety valve's number of deformations.

[0061] Step S202: determining the service life of the battery cell based on the number of deformations of the safety valve.

[0062] The number of times the safety valve deforms can help determine the service life of the battery cell. The number of times the safety valve deforms can reflect the service life of the safety valve, and the service life of the safety valve restricts the service life of the battery cell. Therefore, the number of times the safety valve deforms can be used to determine the service life of the battery cell.

[0063] Figure 5 Schematic diagram of a battery module according to an embodiment of the present invention. Figure 5 As shown, the battery module includes battery cells 51, tabs 52, long bolts 53, end plates A54a, end plates B54b, cable ties 55, and main leads 56 for connecting strain gauges. Tabs 52 are welded to the positive and negative posts at the top of the stacked battery cells 51. Gaps are reserved between the front faces of adjacent battery cells 51, and these gaps are filled with compressible, uniformly thick insulating pads. The battery cells 51 are secured by end plates A54a, end plates B54b, and two cable ties 55. The battery module is secured to the battery pack with long bolts 53. Tabs 52, assembly wiring harness, and strain gauges with adhesive leads 56 are welded to the battery pack.

[0064] In an example of this embodiment, the ratio of the contact area between the end plate A54a and the end plate B54b and the front face 12 of the battery cell to the front face area of ​​the battery cell is 0.8:1 to 1.2:1, preferably 1:1. The number of battery cells is 4 to 20, and 8 to 16 can be selected according to the capacitance and voltage arrangement required by the battery module or battery pack, preferably 11 to 16. An expansion gap of 0.3 to 1 mm is reserved, which is set according to the expansion amount of the battery cell, and can be selected from 0.4 to 0.8 mm, preferably 0.5 to 0.6 mm. The thickness of the insulating pad before compression is 0.5 to 1.4 mm, and can be selected from 0.6 to 1.2 mm, preferably 0.7 to 1.0 mm. The external force for compressing the insulating pad ranges from 2000 to 10000 N. This preload force is determined according to the actual battery cell and operating conditions, preferably 3000 to 8000 N.

[0065] Figure 6 This is a partial schematic diagram of a battery module according to an embodiment of the present invention. Figure 6 As shown, the strain gauge 13 is attached to the safety valve of the battery cell. The strain gauge 13 is connected to the main lead 56 via two leads (61a, 61b) and is used to measure the deformation of the safety valve of each battery cell.

[0066] In this embodiment, a method for predicting the life of a battery cell based on a safety valve is provided. Figure 7 This is a flow chart of determining the deformation of a safety valve according to the variation of the electrical signal of a strain gauge according to an embodiment of the present invention. Figure 7 As shown, the process includes the following steps:

[0067] Step S701: Obtain the variation of the electrical signal of the strain gauge.

[0068] Step S702: Determine the number of deformations of the safety valve corresponding to the electrical signal change using a preset electrical signal change and deformation number lookup table. The preset electrical signal change and deformation number lookup table indicates a one-to-one correspondence between multiple preset electrical signal change amounts and multiple safety valve deformation numbers.

[0069] In this embodiment, a preset lookup table of electrical signal changes and deformation counts is used to find the corresponding safety valve deformation counts for the electrical signal changes. The lookup table is constructed by collecting a large number of electrical signal changes and deformation counts in a laboratory. This table establishes a one-to-one correspondence between multiple preset electrical signal changes and deformation counts for multiple safety valves. The safety valve deformation count can be directly determined based on the electrical signal changes. Optionally, if the electrical signal change of the strain gauge exceeds a preset threshold value twice in a row, a deformation is recorded; if the electrical signal change exceeds the preset threshold value three times in a row, the deformation count is recorded as two; if the electrical signal change exceeds the preset threshold value three times in a row, the deformation count is recorded as two. If the electrical signal change value is less than the preset threshold value and then exceeds the preset threshold value five times in a row, the deformation count is recorded as four, for a total of six deformation counts—the sum of the two times before the electrical signal value falls below the preset threshold value and the four times after the electrical signal value falls below the preset threshold value.

[0070] Figure 8 This is a flow chart of determining the service life of a battery cell based on the number of deformations of a safety valve according to an embodiment of the present invention. Figure 8 As shown, the process includes the following steps:

[0071] Step S801: determining the service life of the safety valve according to the number of deformations of the safety valve.

[0072] Specifically, the above step S801 includes the following steps:

[0073] Step S8011: determining the service life of the safety valve corresponding to the number of deformations of the safety valve from a deformation life curve according to the number of deformations of the safety valve, wherein the deformation life curve indicates a mapping relationship between the number of deformations of the safety valve and the service life of the safety valve.

[0074] In this embodiment, the deformation life curve refers to the relationship between the number of deformations of the safety valve and its service life. Based on the number of deformations of the safety valve obtained in the above steps, the corresponding service life of the safety valve can be determined from the deformation life curve. Thus, the number of deformations of the safety valve is converted into its service life.

[0075] Step S802 : determining the service life of the cell according to the service life of the safety valve and the service life of the electrochemical cell body.

[0076] Specifically, the above step S802 includes the following steps:

[0077] S8021: When the service life of the safety valve is less than the service life of the electrochemical cell, determine the service life of the cell based on the time when the safety valve fails.

[0078] In this embodiment, the lifespan of the electrochemical cell body is calibrated at the factory and represents the number of charge and discharge cycles the chemical material can support. If the service life of the safety valve is less than the lifespan of the electrochemical cell body, this indicates that the safety valve has been damaged by repeated charge and discharge before the electrochemical cell body material loses its charge and discharge capacity, leading to damage to the cell. Therefore, the time until the safety valve fails is used as the service life of the cell.

[0079] S8022: When the service life of the safety valve is greater than the service life of the electrochemical cell body, the service life of the electrochemical cell body shall be used as the service life of the cell.

[0080] In this embodiment, if the service life of the safety valve is greater than the service life of the electrochemical cell body, it means that the number of deformations caused by expansion or contraction due to charging and discharging of the safety valve is small, and the service life of the safety valve is still relatively long, while the material of the electrochemical cell body has lost its charging and discharging ability and reached its service life. Therefore, the service life of the electrochemical cell body is taken as the service life of the cell.

[0081] S8023: When the service life of the safety valve is equal to the service life of the electrochemical cell body, the service life of the safety valve or the service life of the electrochemical cell body shall be used as the service life of the cell.

[0082] In this embodiment, if the service life of the safety valve is equal to the service life of the electrochemical cell body, it means that the loss of charge and discharge capability of the cell and damage to the safety valve will occur simultaneously, and then the service life of the safety valve or the service life of the electrochemical cell body is used as the service life of the cell.

[0083] In this embodiment, the service life of the battery cell is determined by combining the life of the safety valve and the life of the electrochemical cell body, rather than relying solely on the life of the electrochemical body as the service life of the battery cell, thereby improving the accuracy of the prediction of the battery service life.

[0084] In some optional implementations, the following steps are further included before step S8011:

[0085] Step a1: collecting the deformation times of the sample safety valve and the usable times of the sample safety valve and combining them as sample coordinates. The usable times of the sample safety valve indicates the service life of the sample safety valve;

[0086] In this embodiment, the sample safety valve is used to establish a correlation between deformation times and service life. The deformation times x and the service life y of the sample safety valve are measured by collecting a large number of expansion or contraction times of the sample safety valve. These times are then combined to form the sample coordinates (x, y). Alternatively, the service life y of the sample safety valve can be calculated by subtracting the recorded deformation times x from the total number of expansions or contractions N of the sample safety valve at the time of shipment.

[0087] Step a2: Fitting all collected sample coordinates to obtain a fitted curve as a deformation life curve of the safety valve's deformation times and service life.

[0088] By fitting all the sample coordinates (x, y) collected, the obtained fitting curve is used as the deformation life curve of the safety valve, which provides a mathematical model for predicting the service life of the safety valve using the deformation number of the safety valve.

[0089] Figure 9 FIG. 1 is a flow chart of determining the service life of a battery cell according to an embodiment of the present invention. Figure 9As shown, if the safety valve is in good condition, its service life can vary due to fluctuations in the production process, causing it to be shorter or longer than the battery cell's service life. If the safety valve corrodes during assembly or is poorly manufactured, such as with a non-penetrating crack, the crack may propagate after assembly into a battery cell or module and after a period of operation, causing abnormal reciprocating deformation of the safety valve. If the safety valve's service life is shorter than the battery cell's service life or the safety valve's deformation is abnormal, the reciprocating deformation of the safety valve causes abnormal strain gauge deformation (whether it exceeds the threshold or meets the reliability CPK of 1.67), resulting in an abnormal electrical signal transmitted by the strain gauge. If the safety valve's service life exceeds the battery cell's service life or the electrical signal detected by the strain gauge is abnormal, the service life of the battery cell's safety valve is determined based on the electrical signal and a pre-established relationship between the electrical signal and the effects of charge and discharge deformation on the safety valve of a normal battery cell. Furthermore, the battery cell's service life is determined based on the safety valve's service life and the pre-established relationship between the safety valve's service life and the battery cell's service life.

[0090] In this embodiment, a battery cell life prediction device based on a safety valve is also provided. The device is used to implement the above-mentioned embodiments and preferred embodiments. The details that have been described will not be repeated here. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and conceivable.

[0091] This embodiment provides a battery cell life prediction device based on a safety valve. The battery cell includes an electrochemical cell body reflecting the chemical material of the battery cell, a safety valve, and a strain gauge attached to the surface of the safety valve. Figure 10 : is a structural block diagram of a battery cell life prediction device based on a safety valve according to an embodiment of the present invention, such as Figure 10 As shown, including:

[0092] The safety valve deformation determination module 1001 is used to determine the number of deformations of the safety valve generated when the battery cell is charging or discharging based on the change in the electrical signal of the strain gauge;

[0093] The battery cell life determination module 1002 is configured to determine the service life of the battery cell based on the number of deformations of the safety valve.

[0094] In some optional implementations, the safety valve deformation determination module 1001 includes:

[0095] An electrical signal variation acquisition unit, used to acquire the electrical signal variation of the strain gauge;

[0096] The deformation number determination unit is used to determine the deformation number of the safety valve corresponding to the electrical signal change amount using a preset electrical signal change amount and deformation number lookup table. The preset electrical signal change amount and deformation number lookup table indicates a one-to-one correspondence between multiple preset electrical signal change amounts and multiple deformation numbers of safety valves.

[0097] In some optional implementations, the cell life determination module 1002 includes:

[0098] A safety valve service life determination unit is used to determine the service life of the safety valve according to the number of deformations of the safety valve;

[0099] The cell life determination unit is used to determine the service life of the cell according to the service life of the safety valve and the service life of the electrochemical cell body.

[0100] Safety valve service life determination unit, including:

[0101] The first determining subunit is configured to determine the service life of the safety valve corresponding to the number of deformations of the safety valve from a deformation life curve according to the number of deformations of the safety valve, wherein the deformation life curve indicates a mapping relationship between the number of deformations of the safety valve and the service life of the safety valve.

[0102] In some optional implementations, the first determining subunit further includes:

[0103] The deformation times of the sample safety valve and the usable times of the sample safety valve are collected and combined as sample coordinates. The usable times of the sample safety valve indicates the service life of the sample safety valve.

[0104] All collected sample coordinates are fitted, and the fitted curve is obtained as the deformation life curve of the safety valve's deformation times and service life.

[0105] In some optional embodiments, the cell life determination unit includes:

[0106] A first cell life determination subunit is configured to determine the cell life according to the time of failure of the safety valve when the service life of the safety valve is less than the service life of the electrochemical cell body;

[0107] A second cell life determination subunit is configured to use the life of the electrochemical cell body as the service life of the cell when the service life of the safety valve is greater than the service life of the electrochemical cell body;

[0108] The third cell life determining subunit is configured to use the service life of the safety valve or the service life of the electrochemical cell body as the service life of the cell when the service life of the safety valve is equal to the service life of the electrochemical cell body.

[0109] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0110] The battery cell life prediction device in this embodiment is presented in the form of a functional unit, where the unit refers to an application specific integrated circuit (ASIC) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0111] The embodiment of the present invention also provides a computer device having the above Figure 10 The battery cell life prediction device based on the safety valve is shown.

[0112] See also Figure 11 , Figure 11 This is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention. Figure 11 As shown, the computer device includes: one or more processors 10, memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components utilize different buses to communicate with each other and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in the memory or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Equally, multiple computer devices can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 11 A processor 10 is taken as an example.

[0113] The processor 10 may be a central processing unit, a network processor, or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic, or any combination thereof.

[0114] The memory 20 stores instructions that can be executed by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0115] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created based on the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0116] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0117] The computer device further includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means. Figure 11 The bus connection is taken as an example.

[0118] The input device 30 can receive input digital or character information and generate key signal input related to user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a trackpad, a touch pad, an indicator stick, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 can include a display device, an auxiliary lighting device (e.g., an LED), and a tactile feedback device (e.g., a vibration motor). The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display, and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0119] The embodiment of the present invention also provides a computer-readable storage medium. The above-mentioned method according to the embodiment of the present invention can be implemented in hardware, firmware, or implemented as a computer code that can be recorded in a storage medium, or implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state drive, etc.; further, the storage medium can also include a combination of the above-mentioned types of memory. It can be understood that a computer, a processor, a microprocessor controller or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor or hardware, the method shown in the above embodiment is implemented.

[0120] A portion of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the form in which the computer program instruction exists in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc. Accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium that can be accessed by the computer.

[0121] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for predicting the life of a battery cell based on a safety valve, characterized in that: The battery cell includes an electrochemical battery cell body reflecting the chemical material of the battery cell, a safety valve, and a strain gauge attached to the surface of the safety valve. The method includes: determining, based on a change in an electrical signal from the strain gauge, a number of deformations of the safety valve during charging or discharging of the battery cell; The service life of the battery cell is determined based on the number of deformations of the safety valve.

2. The method according to claim 1, characterized in that The step of determining the number of deformations of the safety valve during charging or discharging of the battery cell based on the change in the electrical signal of the strain gauge includes: Obtaining a change in the electrical signal of the strain gauge; The number of deformations of the safety valve corresponding to the electrical signal change is determined using a preset electrical signal change and deformation number lookup table, wherein the preset electrical signal change and deformation number lookup table indicates a one-to-one correspondence between multiple preset electrical signal change amounts and multiple deformation numbers of safety valves.

3. The method according to claim 1, characterized in that The determining the service life of the battery cell based on the number of deformations includes: determining the service life of the safety valve according to the number of deformations of the safety valve; The service life of the cell is determined according to the service life of the safety valve and the service life of the electrochemical cell body.

4. The method according to claim 3, characterized in that Determining the service life of the safety valve according to the number of deformations of the safety valve includes: According to the number of deformations of the safety valve, the service life of the safety valve corresponding to the number of deformations of the safety valve is determined from a deformation life curve, wherein the deformation life curve indicates a mapping relationship between the number of deformations of the safety valve and the service life of the safety valve.

5. The method according to claim 4, characterized in that Before determining the service life of the safety valve corresponding to the number of deformations of the safety valve from a deformation life curve according to the number of deformations of the safety valve, the method further includes: collecting the number of deformations of the sample safety valve and the number of usable times of the sample safety valve and combining them as sample coordinates, wherein the number of usable times of the sample safety valve indicates the service life of the sample safety valve; All collected sample coordinates are fitted, and the fitted curve is obtained as the deformation life curve of the safety valve's deformation times and service life.

6. The method according to claim 3, characterized in that The determining the service life of the cell according to the service life of the safety valve and the service life of the electrochemical cell body comprises: When the service life of the safety valve is less than the service life of the electrochemical cell body, determining the service life of the cell according to the time when the safety valve fails; When the service life of the safety valve is greater than the service life of the electrochemical cell body, the service life of the electrochemical cell body is used as the service life of the cell; When the service life of the safety valve is equal to the service life of the electrochemical cell body, the service life of the safety valve or the service life of the electrochemical cell body is taken as the service life of the cell.

7. A battery cell life prediction device based on a safety valve, characterized in that: The battery cell includes an electrochemical cell body reflecting the chemical material of the battery cell, a safety valve, and a strain gauge attached to the surface of the safety valve. The device includes: a deformation determination module, configured to determine, based on a change in an electrical signal from the strain gauge, a number of deformations of the safety valve during charging or discharging of the battery cell; The service life determination module is used to determine the service life of the battery cell based on the number of deformations of the safety valve.

8. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the battery cell life prediction method based on a safety valve according to any one of claims 1 to 6 by executing the computer instructions.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the battery cell life prediction method based on a safety valve according to any one of claims 1 to 6.

10. A computer program product, characterized in that The method comprises computer instructions for causing a computer to execute the method for predicting the life of a battery cell based on a safety valve according to any one of claims 1 to 6.

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