Evaluation method of battery packaging, electronic equipment, storage medium and program product

Abstract

The embodiment of the invention provides a battery packaging evaluation method, electronic equipment, a storage medium and a program product. The method comprises the following steps: determining that an evaluation result of battery packaging is invalid or safe according to a liquid loss parameter and a critical parameter of a wet-sealed battery electrolyte; wherein when the fluid loss parameter comprises the fluid loss amount, the critical parameter comprises the critical fluid loss amount or further comprises the critical mass concentration; wherein when the liquid loss parameter comprises the mass concentration of the electrolyte at the sealing position after wet sealing, the critical parameter comprises the critical mass concentration or further comprises the critical liquid loss amount. The method is used for obtaining the packaging effect of the soft package battery under the condition of reducing the cost.

Description

Technical Field

[0001] The present application relates to the field of lithium-ion batteries, and in particular to a battery packaging evaluation method, electronic equipment, storage medium and program product. Background Art

[0002] Soft-pack batteries (soft-pack lithium batteries) have become one of the most important products in the field of new energy due to their advantages of light weight, high energy density, and flexible shape. As a key component of soft-pack batteries, aluminum-plastic composite film is generally composed of nylon layer, adhesive, aluminum layer and polypropylene (Poly Propylene, referred to as PP) layer. Soft-pack batteries are encapsulated by thermal fusion of the PP layer of the double-layer aluminum-plastic film. Good encapsulation effect can effectively prevent lithium-ion batteries from leaking, bloating, and even explosion.

[0003] According to the seal position, the packaging of soft-pack batteries is generally divided into the following processes: side sealing, top sealing, airbag pre-sealing and secondary sealing. Among them, side sealing (also known as dry sealing) and secondary sealing (also known as wet sealing) are carried out under dry batteries and wet batteries, respectively. During the wet sealing process, the electrolyte is easy to remain in the seal, resulting in a decrease in the seal peeling strength and affecting the packaging effect. Especially in the lying degassing (Degas) process, when the electrolyte is extracted, it flows from the battery body through the seal to the airbag, and the probability of residue at the seal is greatly increased. Therefore, in order to ensure the packaging effect of the soft-pack battery, the packaging of the soft-pack battery needs to be tested.

[0004] At present, when testing the packaging of soft-pack batteries, not only is the testing environment demanding, but it will also damage the packaged soft-pack batteries, which is costly. How to know the packaging effect of soft-pack batteries while reducing costs is still a problem that needs to be solved. Summary of the invention

[0005] The embodiments of the present application provide a battery packaging evaluation method, electronic device, storage medium and program product, which are used to achieve the effect of knowing the packaging effect of soft-pack batteries while reducing costs.

[0006] In a first aspect, an embodiment of the present application provides a battery packaging evaluation method, comprising:

[0007] Determine whether the evaluation result of the battery packaging is failure or safety based on the liquid loss parameters and critical parameters of the battery electrolyte after wet sealing;

[0008] Wherein, when the fluid loss parameter includes the fluid loss amount, the critical parameter includes the critical fluid loss amount, or also includes the critical mass concentration;

[0009] Wherein, when the fluid loss parameter includes the mass concentration of the electrolyte at the seal after wet sealing, the critical parameter includes the critical mass concentration, or also includes the critical fluid loss amount.

[0010] In a possible implementation manner, when the fluid loss parameter includes the amount of fluid loss, the method further includes:

[0011] The amount of electrolyte loss in the battery after wet sealing is determined based on the first weight of the battery after electrolyte is injected, the length of the air pocket generated by the battery packaging, the width of the air pocket, the density of the aluminum-plastic film surface and the second weight of the finished battery.

[0012] In a possible implementation, determining the amount of electrolyte loss in the battery after wet sealing according to the first weight of the battery after the electrolyte is injected, the length of the air pocket generated by the battery packaging, the width of the air pocket, the density of the aluminum-plastic film surface, and the second weight of the finished battery includes:

[0013] Determining a reference weight according to the length of the air pocket generated by the battery packaging, the width of the air pocket and the density of the aluminum-plastic film surface;

[0014] The amount of electrolyte loss in the battery after wet sealing is determined according to the first weight, the second weight and the reference weight.

[0015] In a possible implementation manner, determining the reference weight according to the length of the air pocket generated by the battery packaging, the width of the air pocket and the density of the aluminum-plastic film surface includes:

[0016] The reference weight is determined according to the formula B=Wq×Lq×ρ, wherein B represents the reference weight, Wq represents the width of the air bag, Lq represents the length of the air bag, and ρ represents the density of the aluminum-plastic film surface.

[0017] In a possible implementation manner, determining the amount of electrolyte loss of the battery after wet sealing according to the first weight, the second weight and the reference weight includes:

[0018] According to the formula A=m1-m2-B, the amount of electrolyte loss of the battery after wet sealing is determined; wherein A represents the amount of electrolyte loss of the battery after wet sealing, m1 represents the first weight, m2 represents the second weight, and B represents the reference weight.

[0019] In a possible implementation, determining the amount of electrolyte loss in the battery after wet sealing according to the first weight of the battery after the electrolyte is injected, the length of the air pocket generated by the battery packaging, the width of the air pocket, the density of the aluminum-plastic film surface, and the second weight of the finished battery includes:

[0020] Determining a reference weight according to the length of the air pocket generated by the battery packaging, the width of the air pocket and the density of the aluminum-plastic film surface;

[0021] The amount of electrolyte loss in the battery after wet sealing is determined according to the first weight, the second weight and the reference weight.

[0022] In a possible implementation, when the fluid loss parameter includes the fluid loss amount, determining whether the evaluation result of the battery package is failure or safety according to the fluid loss amount and the critical parameter includes:

[0023] When the liquid loss amount is less than or equal to the critical liquid loss amount, determining that the evaluation result of the battery package is failure;

[0024] When the liquid loss amount is greater than the critical liquid loss amount, the evaluation result of the battery package is determined to be safe.

[0025] In a possible implementation manner, the critical liquid loss amount includes a first critical liquid loss amount and a second critical liquid loss amount, the failure includes a first level failure and a second level failure, and when the liquid loss amount is less than or equal to the critical liquid loss amount, determining that the evaluation result of the battery package is a failure includes:

[0026] When the liquid loss amount is less than or equal to the first critical liquid loss amount, determining that the evaluation result of the battery package is a first level failure;

[0027] When the liquid loss amount is greater than the first critical liquid loss amount and less than or equal to the second critical liquid loss amount, it is determined that the evaluation result of the battery package is a second level failure.

[0028] In a possible implementation manner, when the liquid loss amount is greater than the critical liquid loss amount, determining that the evaluation result of the battery package is safe includes:

[0029] When the liquid loss amount is greater than the second critical liquid loss amount, it is determined that the evaluation result of the battery package is safe.

[0030] In a possible implementation, when the liquid loss parameter includes mass concentration, determining whether the evaluation result of the battery package is failure or safety according to the liquid loss parameter and the critical parameter includes:

[0031] When the mass concentration is greater than or equal to the critical mass concentration, determining that the evaluation result of the battery package is failure;

[0032] When the mass concentration is less than the critical mass concentration, it is determined that the evaluation result of the battery packaging is safe.

[0033] In a possible implementation manner, the critical mass concentration includes a first critical mass concentration and a second critical mass concentration; the failure includes a first level failure and a second level failure;

[0034] When the mass concentration is greater than or equal to the critical mass concentration, determining that the evaluation result of the battery package is failure includes:

[0035] When the mass concentration is greater than or equal to the first critical mass concentration, determining that the evaluation result of the battery package is a first level failure;

[0036] When the mass concentration is less than the first critical mass concentration and greater than or equal to the second critical mass concentration, it is determined that the evaluation result of the battery package is a second level failure.

[0037] In a possible implementation, when the mass concentration is less than or equal to the critical mass concentration, determining that the evaluation result of the battery package is safe includes:

[0038] When the mass concentration is less than the second critical mass concentration, it is determined that the evaluation result of the battery package is safe.

[0039] In a possible implementation manner, when the fluid loss parameter includes the fluid loss amount, and the critical parameter also includes a critical mass concentration, the method further includes:

[0040] According to the liquid loss amount, the evaporation amount of the solvent in the electrolyte lost after the battery is wet sealed, and the residual liquid coefficient, the mass concentration of the electrolyte at the seal after wet sealing is determined, and the mass concentration is used as one of the liquid loss parameters.

[0041] In a possible implementation, determining the mass concentration of the battery electrolyte after wet sealing according to the liquid loss, the evaporation amount of the solvent in the electrolyte lost after the battery is wet sealed, and the residual liquid coefficient includes:

[0042] The mass concentration is determined according to the formula c=k×A×12.9% / (k×A-bl); wherein c represents the mass concentration, A represents the liquid loss, k represents the residual liquid coefficient, and bl represents the evaporation amount.

[0043] In a possible implementation, when the critical parameter includes a critical liquid loss amount, before obtaining the liquid loss amount of the battery electrolyte after wet sealing, the method further includes:

[0044] Obtaining electrolyte loss of multiple batteries after wet sealing and packaging performance parameters of multiple batteries after wet sealing;

[0045] The critical liquid loss amount is determined according to the electrolyte loss amount of the multiple batteries after wet sealing and the packaging performance parameters of the multiple batteries after wet sealing.

[0046] In a possible implementation, when the critical parameter includes a critical mass concentration, before obtaining the amount of liquid loss of the battery electrolyte after wet sealing, the method further includes:

[0047] Obtaining electrolyte loss of multiple batteries after wet sealing and packaging performance parameters of multiple batteries after wet sealing;

[0048] For each of the plurality of batteries, determining the mass concentration of the electrolyte at the battery seal according to the amount of electrolyte loss of the battery after wet sealing;

[0049] The critical mass concentration is determined according to the mass concentration of the electrolyte at the seal of each battery in the plurality of batteries and the packaging performance parameters of each battery after wet sealing.

[0050] In a second aspect, the present application provides a battery packaging evaluation device, comprising:

[0051] A processing module, used to determine whether the evaluation result of the battery packaging is failure or safety according to the liquid loss parameter and critical parameter of the battery electrolyte after wet sealing;

[0052] Wherein, when the fluid loss parameter includes the fluid loss amount, the critical parameter includes the critical fluid loss amount, or also includes the critical mass concentration;

[0053] Wherein, when the fluid loss parameter includes mass concentration, the critical parameter includes critical mass concentration, or also includes critical fluid loss amount.

[0054] In a third aspect, an embodiment of the present application provides an electronic device, including: a memory, a processor;

[0055] The memory stores computer-executable instructions;

[0056] The processor executes the computer-executable instructions stored in the memory, so that the processor executes the above first aspect and / or various possible implementations of the first aspect.

[0057] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the first aspect above and / or various possible implementations of the first aspect.

[0058] In a fifth aspect, an embodiment of the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the above first aspect and / or various possible implementation methods of the first aspect.

[0059] The battery packaging evaluation method, electronic device, storage medium and program product provided in the embodiments of the present application determine the evaluation result of the battery packaging by measuring the amount of electrolyte loss in the battery after wet sealing, without destroying the packaged soft-pack battery, thus reducing the cost of obtaining the packaging effect of the soft-pack battery. In addition, in terms of factors affecting packaging failure, the prediction of the impact of foreign matter residues such as electrolyte at the seal of the wet sealing process has been expanded, which is of great significance for ensuring the heat sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0061] Figure 1 The results of Fourier infrared testing of normal aluminum-plastic film and aluminum-plastic film with poor heat sealing in the battery provided by this application;

[0062] Figure 2 Schematic diagram of the process of evaluating the battery packaging provided in this application Figure 1 ;

[0063] Figure 3 Schematic diagram of the process of evaluating the battery packaging provided in this application Figure 2 ;

[0064] Figure 4 Schematic diagram of the process of evaluating the battery packaging provided in this application Figure 3 ;

[0065] Figure 5 Schematic diagram of the process of evaluating the battery packaging provided in this application Figure 4 ;

[0066] Figure 6 A schematic diagram of the structure of the battery packaging evaluation device provided in this application;

[0067] Figure 7 A schematic diagram of the structure of the electronic device provided in this application.

[0068] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0069] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0070] The specific application scenario of this application is to evaluate the packaging of soft-pack batteries (soft-pack lithium batteries).

[0071] Soft-pack batteries (soft-pack lithium batteries) have become one of the most important products in the field of new energy due to their advantages of light weight, high energy density, and flexible shape. As a key component of soft-pack batteries, aluminum-plastic composite film is generally composed of nylon layer, adhesive, aluminum layer and polypropylene (Poly Propylene, referred to as PP) layer. Soft-pack batteries are encapsulated by thermal fusion of the PP layer of the double-layer aluminum-plastic film. Good encapsulation effect can effectively prevent lithium-ion batteries from leaking, bloating, and even explosion.

[0072] According to the seal position, the packaging of soft pack batteries is generally divided into the following processes: side sealing, top sealing, air bag pre-sealing and secondary sealing. Among them, side sealing (also known as dry sealing) and secondary sealing (also known as wet sealing) are carried out under dry batteries and wet batteries respectively.

[0073] During the wet seal process, electrolyte is likely to remain at the seal, causing the seal peel strength to decrease and affecting the packaging effect. Especially in the flat degassing process, when the electrolyte is extracted, it flows from the battery body through the seal to the air bag, and the probability of residual at the seal increases significantly.

[0074] The electrolyte residue at the seal will directly affect the sealing effect at the seal. In previous experiments, the thickness of the wet-sealed defective sites was measured. After encapsulation, the thickness of the two aluminum-plastic films at the same bonding site were 180 microns (μm) and 178μm, respectively, which were both higher than the unencapsulated aluminum-plastic film incoming material detection thickness of 153μm. Through microscopic measurement, the thickness of the unencapsulated aluminum-plastic film, the encapsulated aluminum-plastic film and the aluminum-plastic film PP layer at the defective site were 73.56μm, 46.89μm and 100.56μm, respectively. The thickness of the aluminum-plastic film PP layer at the defective site is significantly higher than that of the unencapsulated aluminum-plastic film PP layer, indicating that the surface of the defective site contains foreign matter, resulting in excessive thickness.

[0075] Further Fourier infrared (FTIR) tests were performed on normal aluminum-plastic films and aluminum-plastic films with poor heat sealing sites. The results are as follows: Figure 1 As shown. The aluminum-plastic film at the poor heat-sealing site is at 841.92 cm -1 and 560.59cm -1 There are two strong absorption peaks, which can be attributed to hexafluorophosphate (PF 6 - )'s phosphorus-fluorine (PF) bond stretching vibration and bending, indicating that the foreign matter at the seal is the precipitated hexafluorophosphate (LiPF 6 ) crystals. The cells after injection and after fractionation were kept at 75℃ for 12h, and then disassembled and directly observed for crystallization on the aluminum-plastic film. No crystallization was found, indicating that LiPF 6 It is generated in the Degas wet sealing stage and directly affects the wet sealing effect of the soft-pack battery.

[0076] Therefore, in order to ensure the packaging effect of soft-pack batteries, the packaging of soft-pack batteries needs to be tested.

[0077] Currently, when testing the packaging of soft-pack batteries, not only is the testing environment demanded to be high, but the packaged soft-pack batteries will also be damaged, resulting in high costs.

[0078] How to achieve the packaging effect of soft-pack batteries while reducing costs still needs to be solved.

[0079] The battery packaging evaluation method provided in the present application is a technical means for determining the battery packaging effect by the amount of battery electrolyte loss after wet sealing, which solves the technical problem of high cost in the prior art when obtaining the packaging effect of soft-pack batteries.

[0080] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0081] Figure 2 Schematic diagram of the process of evaluating the battery packaging provided in this application Figure 1 ,like Figure 2 As shown, the method includes:

[0082] S201. Determine whether the evaluation result of the battery packaging is failure or safety according to the liquid loss parameter and critical parameter of the battery electrolyte after wet sealing.

[0083] Wherein, when the fluid loss parameter includes the fluid loss amount, the critical parameter includes the critical fluid loss amount, or also includes the critical mass concentration. Optionally, when the critical parameter also includes the critical mass concentration, the mass concentration of the battery electrolyte after wet sealing is determined according to the fluid loss amount, and then the mass concentration is compared with the critical mass concentration.

[0084] Wherein, when the fluid loss parameter includes the mass concentration of the electrolyte at the seal after wet sealing, the critical parameter includes the critical mass concentration, or also includes the critical fluid loss amount. Optionally, when the critical parameter also includes the critical fluid loss amount, the fluid loss amount of the battery electrolyte after wet sealing can be determined according to the mass concentration, and then the fluid loss amount is compared with the critical fluid loss amount.

[0085] Before determining the evaluation result of the battery packaging, the liquid loss amount or the mass concentration of the battery electrolyte after wet sealing needs to be obtained. When obtaining the mass concentration, the liquid loss amount can be obtained first, and then the mass concentration can be calculated based on the liquid loss amount, or the mass concentration can be obtained by other methods, which is not limited in this embodiment.

[0086] Among them, the amount of electrolyte extracted from the battery during the Degas process is defined as the liquid loss.

[0087] The amount of liquid loss can be obtained by weighing without destroying the packaged battery.

[0088] It is understandable that during the electrolyte extraction process of the Degas process, according to the Bernoulli equation, when the fluid cross section remains unchanged, the liquid is at the same height, and the liquid flow rate in the seal area and the air bag area is consistent. Therefore, the more liquid is lost, the more electrolyte stays at the seal. Assuming that the amount of liquid loss is A and the amount of electrolyte at the seal is b, the ideal relationship between A and b is b = k × A. Where k is the residual liquid coefficient, which is the ratio of the seal width Wf to the air bag width Wq, and can be taken as k = 7 / 80.

[0089] During the Degas packaging process, the overall temperature of the seal is relatively high (about 180°C) and the air pressure is relatively low (about 40kPa). The state of the electrolyte around the seal is different from other processes. Specifically, the low air pressure in the battery cavity can reduce the boiling point of the electrolyte solvent at the seal, and the high temperature of the head can make part of the solvent reach the boiling point corresponding to the cavity air pressure, and the electrolyte solvent evaporates. It can be seen from the Mazak formula that when the external environment is the same, the evaporation amount of the solvent (set as bl) is only related to the saturated vapor pressure.

[0090] Therefore, under the condition of the same solvent evaporation amount, the smaller the liquid loss amount A, the higher the electrolyte concentration at the seal, the greater the electrolyte viscosity, and the more difficult it is for the electrolyte to be discharged to both sides when the head is pressed down. At this time, the continuous heating of the head makes it easy for crystallization to occur at the seal, resulting in poor packaging of the soft-pack battery. The larger the liquid loss amount A, the smaller the electrolyte concentration at the seal, the smaller the electrolyte viscosity, and the easier it is for the electrolyte to be discharged to both sides when the head is pressed down, which is beneficial to the packaging of the soft-pack battery. When the electrolyte concentration is lower than a certain safety threshold, the packaging effect of the battery can be guaranteed. In general, when the liquid loss amount A changes from small to large, there is a critical concentration of the electrolyte at the seal. Above the critical concentration, the seal will produce crystallization, causing poor packaging, and below the critical concentration, the packaging is good.

[0091] As described above, the liquid loss amount A and the electrolyte concentration at the seal are both related to the packaging effect at the seal. Therefore, by using the critical liquid loss amount and the critical mass concentration as critical parameters and comparing them with the obtained liquid loss amount or the mass concentration, the evaluation result of the battery packaging can be determined.

[0092] Among them, the critical parameter can be obtained according to the experiment before evaluating the battery packaging (before executing step S201). Specifically, the packaging performance parameters of a large number of batteries are obtained, and the critical parameter is determined according to the packaging performance parameters. The packaging performance parameters may include the amount of crystallization, thickness, bubble defect rate, sol defect rate, etc. at the packaging. When obtaining the packaging performance parameters, they can be measured and obtained after disassembling the soft-pack battery.

[0093] The critical parameter may also be set according to actual needs, and is not limited in this embodiment.

[0094] The evaluation results of battery packaging are failure or safety. Failure means that the battery packaging effect is not good, which can be understood as invalid packaging. Safety means that the battery packaging effect is good, which can be understood as effective packaging.

[0095] Optionally, as described above, the smaller the liquid loss amount A, the easier it is to cause poor packaging of the soft-pack battery. On the contrary, the larger the liquid loss amount A, the more beneficial it is to the packaging of the soft-pack battery. Therefore, when the liquid loss amount is less than or equal to the critical liquid loss amount, it can be determined that the evaluation result of the battery packaging is failure. When the liquid loss amount is greater than the critical liquid loss amount, it can be determined that the evaluation result of the battery packaging is safe.

[0096] Optionally, as described above, the smaller the amount of liquid loss A, the higher the electrolyte concentration at the seal, and the easier it is to cause poor packaging of the soft-pack battery. On the contrary, when the amount of liquid loss A is larger, the lower the electrolyte concentration at the seal, the more beneficial it is to the packaging of the soft-pack battery. Therefore, the mass concentration of the electrolyte at the seal can be determined based on the amount of liquid loss. When the mass concentration of the electrolyte at the seal is greater than the critical mass concentration, the evaluation result of the battery packaging can be determined to be failure. When the mass concentration of the electrolyte at the seal is less than or equal to the critical mass concentration, the evaluation result of the battery packaging can be determined to be safe.

[0097] The battery packaging evaluation method provided in the embodiment of the present application includes: determining whether the battery packaging evaluation result is failure or safety based on the liquid loss parameters and critical parameters of the battery electrolyte after wet sealing; wherein the critical parameters include critical liquid loss amount and / or critical mass concentration.

[0098] At present, the detection of battery packaging effect is destructive, and the requirements for the detection environment are high, which has caused difficulties for mass production. This embodiment determines the evaluation result of battery packaging by the amount of battery electrolyte lost after wet sealing. It does not need to destroy the packaged soft-pack battery, which reduces the cost of knowing the packaging effect of the soft-pack battery. In addition, in terms of factors affecting packaging failure, the prediction of the influence of foreign matter residues such as electrolyte at the seal of the wet sealing process has been expanded, which is of great significance to ensuring the heat sealing effect.

[0099] In some embodiments, when the fluid loss parameter includes the fluid loss amount, the battery packaging evaluation method further includes:

[0100] Step 1: Determine the amount of electrolyte loss after wet sealing based on the first weight of the battery after electrolyte injection, the length of the air pocket generated by the battery packaging, the width of the air pocket, the density of the aluminum-plastic film surface and the second weight of the finished battery.

[0101] Specifically, the reference weight is first determined according to the length of the air pocket generated by the battery packaging, the width of the air pocket and the density of the aluminum-plastic film surface, and then the amount of electrolyte loss of the battery after wet sealing is determined according to the first weight, the second weight and the reference weight.

[0102] For example, the reference weight is determined according to the formula B = Wq × Lq × ρ, where B represents the reference weight, Wq represents the width of the airbag, Lq represents the length of the airbag, and ρ represents the density of the aluminum-plastic film surface. The amount of electrolyte loss after wet sealing is determined according to the formula A = m1-m2-B, where A represents the amount of electrolyte loss after wet sealing, m1 represents the first weight, m2 represents the second weight, and B represents the reference weight.

[0103] The above formula can also be expressed as A=m1-m2-Wq×Lq×ρ, where A represents the amount of electrolyte loss after wet sealing, m1 represents the first weight, m2 represents the second weight, Wq represents the width of the air bag, Lq represents the length of the air bag, and ρ represents the density of the aluminum-plastic film surface.

[0104] It should be noted that the acquisition of the length and width of the airbag does not require the destruction of the packaged battery, and only requires measurement, which is a simple acquisition method. The acquisition of the first weight and the second weight also does not require the destruction of the packaged battery, and only requires recording the weight during the corresponding process.

[0105] Therefore, the method provided in this embodiment is not only simple and efficient in obtaining the amount of electrolyte loss of the battery after wet sealing, but also does not require destroying the packaged battery and is low in cost.

[0106] Figure 3 Schematic diagram of the process of evaluating the battery packaging provided in this application Figure 2 ,like Figure 3 As shown, in this embodiment Figure 2 Based on the examples, the evaluation method of the battery package is described in detail.

[0107] When the fluid loss parameter includes the fluid loss amount, and the critical parameter includes the critical fluid loss amount, the method includes:

[0108] S301. When the liquid loss amount is less than or equal to the critical liquid loss amount, determining that the evaluation result of the battery package is failure.

[0109] When the electrolyte concentration remains unchanged, different liquid loss amounts have different effects on poor packaging. Therefore, the relationship between different liquid loss amounts and the evaluation results of battery packaging is established, which is conducive to avoiding poor packaging at the level of battery liquid loss design and is conducive to the prediction of actual production packaging effects.

[0110] The critical fluid loss amount can be obtained based on historical experience or set according to actual needs.

[0111] For example, when the critical liquid loss is 3 grams (g), when the liquid loss is less than or equal to 3 g, the evaluation result of the battery package is determined to be failure.

[0112] S302: When the liquid loss amount is greater than the critical liquid loss amount, determine that the evaluation result of the battery package is safe.

[0113] For example, when the critical liquid loss is 3 g, when the liquid loss is greater than 3 g, the evaluation result of the battery package is determined to be safe.

[0114] Optionally, when obtaining the critical liquid loss, packaging performance parameters of a large number of batteries are obtained, and the critical parameter is determined according to the packaging performance parameters. The packaging performance parameters are the packaging defect rate described below.

[0115] A method for obtaining the critical fluid loss is described below.

[0116] Optionally, in the battery packaging process, the battery is wet-sealed while Degas is performed, and the wet-sealing temperature is 170 degrees Celsius (℃), the insulation time is 8 seconds (s), and the pressure is 200 kilograms (kg). After the wet-sealing is completed, the air bag part is cut off, and then the finished battery is obtained after folding and hot edge processing. Select several qualified finished batteries with liquid loss above a~b, b~c, c~d, d~e, f~L0 and L0 for disassembly, and then cut the seal of the wet seal, perform thickness test and peel test on the seal, observe and record the failure cause, peeling and sol state.

[0117] The seals cut from the air bag side of finished batteries with liquid loss a-b, b-c, c-d, d-e, f-L0 and above L0 were peeled off, and three types of poor wet sealing phenomena were found: unmelted glue penetration channel, local poor melting of glue and bubbles.

[0118] In detail, when the amount of liquid loss is between a and b, the packaging defect rate after disassembly is 75%, of which air bubble defect, adhesive melt defect, and unmelted adhesive penetrating channel account for 55.55%, 33.33%, and 11.11%, respectively.

[0119] When the amount of liquid loss is between b and c, the packaging defect rate after disassembly is 75%, of which air bubble defect, adhesive melt defect and unmelted adhesive penetrating channel account for 33.33%, 66.67% and 0% respectively.

[0120] When the amount of liquid loss is between c and d, the packaging defect rate after disassembly is 75%, of which air bubble defect, adhesive melt defect and unmelted adhesive penetrating channel account for 0%, 33.33% and 66.67% respectively.

[0121] When the liquid loss is between d and e, the packaging defect rate after disassembly is 45.45%, of which air bubble defect, adhesive melt defect and unmelted adhesive penetrating channel account for 40%, 40% and 20% respectively.

[0122] When the liquid loss is between e and f, the packaging defect rate after disassembly is 24.14%, of which air bubble defect, adhesive melt defect and unmelted adhesive penetrating channel account for 42.86%, 57.14% and 0% respectively.

[0123] When the amount of liquid loss is between f and L0, the defective rate of packaging after disassembly is 28.57%, of which air bubble defect, adhesive melt defect, and unmelted adhesive penetrating channel account for 100%, 0%, and 0%, respectively.

[0124] When the liquid loss is less than L0, the packaging defective rates are 75%, 46.67% and 22.22% under the liquid loss ranges of a~b, b~d and d~L0, respectively.

[0125] In summary, when the amount of liquid loss is less than L0, the packaging defective rates under the conditions of a-b, b-d and d-L0 are 75%, 46.67% and 22.22% respectively. It can be seen that as the amount of liquid loss decreases, the defective rate increases. The probability of packaging defective is very high when the amount of liquid loss is between a and d. A total of 67 batteries were disassembled, and 28 batteries were defective, of which 46.43% (13 pcs) were defective bubbles, 39.29% (11 pcs) were defective melts, and 14.29% (4 pcs) were unmelted glue through the channel. When the amount of liquid loss is greater than L0, no packaging defect occurs.

[0126] At this time, L0 can be defined as the critical liquid loss amount. When the liquid loss amount obtained in step S201 is less than or equal to L0, the evaluation result of the battery package is determined to be failure. When the liquid loss amount obtained in step S201 is greater than L0, the evaluation result of the battery package is determined to be safe.

[0127] The method provided in this embodiment determines the evaluation result of battery packaging by measuring the amount of electrolyte loss in the battery after wet sealing, without destroying the packaged soft-pack battery, thus reducing the cost of obtaining the packaging effect of the soft-pack battery. In addition, in terms of factors affecting packaging failure, the prediction of the influence of foreign matter residues such as electrolyte at the seal of the wet sealing process has been expanded, which is of great significance for ensuring the heat sealing effect.

[0128] For some examples, see Figure 4 , the critical fluid loss includes a first critical fluid loss and a second critical fluid loss, and the failure includes a first level failure and a second level failure. Wherein, the first critical fluid loss is less than the second critical fluid loss.

[0129] When determining the evaluation results of the battery packaging effect, include:

[0130] Step 1: When the liquid loss amount is less than or equal to the first critical liquid loss amount, determining that the evaluation result of the battery package is a first level failure.

[0131] As described above, it can be known that the smaller the liquid loss, the worse the corresponding battery packaging effect. The larger the liquid loss, the better the corresponding battery packaging effect. Therefore, when the liquid loss is less than or equal to the first critical liquid loss, it proves that the packaging is seriously defective, and the evaluation result of the corresponding battery packaging is the first level failure. The first level failure can be understood as a serious failure.

[0132] The first critical liquid loss amount can be obtained based on the packaging performance parameters of the packaged batteries. For example, the packaging performance parameters of a large number of batteries are obtained, and the first critical liquid loss amount is determined based on the packaging performance parameters. The packaging performance parameters are the packaging defect rate described above.

[0133] The first critical liquid loss is, for example, 1.4 g. Assuming that the liquid loss of the battery electrolyte after wet sealing is A, when 0 g ≤ A ≤ 1.4 g, it is proved that serious packaging failure occurs.

[0134] Step 2: When the liquid loss amount is greater than the first critical liquid loss amount and less than or equal to the second critical liquid loss amount, determining that the evaluation result of the battery package is a second-level failure.

[0135] As described above, it can be known that the smaller the liquid loss, the worse the corresponding battery packaging effect. The larger the liquid loss, the better the corresponding battery packaging effect. Therefore, when the liquid loss is greater than the first critical liquid loss and less than or equal to the second critical liquid loss, it is proved that poor packaging occurs, and the evaluation result of the corresponding battery packaging is a second-level failure. The second-level failure can be understood as a failure or a common failure.

[0136] The second critical liquid loss amount can be obtained based on the packaging performance parameters of the packaged battery. For example, the packaging performance parameters of a large number of batteries are obtained, and the second critical liquid loss amount is determined based on the packaging performance parameters. The packaging performance parameters are the packaging defect rate described above.

[0137] The second critical liquid loss is, for example, 3 g. Assuming that the liquid loss of the battery electrolyte after wet sealing is A, when 1.4 g < A ≤ 3 g, it is proved that packaging failure occurs.

[0138] Step three: when the liquid loss amount is greater than the second critical liquid loss amount, determining that the evaluation result of the battery package is safe.

[0139] As described above, it can be known that the smaller the liquid loss, the worse the corresponding battery packaging effect. The larger the liquid loss, the better the corresponding battery packaging effect. Therefore, when the liquid loss is greater than the second critical liquid loss, it proves that the battery packaging effect is good, and the corresponding battery packaging evaluation result is safe.

[0140] The second critical liquid loss is, for example, 3 g. Assuming that the liquid loss of the battery electrolyte after wet sealing is A, when 3 g < A, it proves that the packaging effect is good, and the evaluation result of the corresponding battery packaging is safe.

[0141] The method provided in this embodiment further distinguishes different levels of failure when the evaluation result of the battery package is failure. That is, the critical liquid loss is set to include a first critical liquid loss and a second critical liquid loss, and the failure includes a first-level failure and a second-level failure. When the liquid loss is less than or equal to the first critical liquid loss, the evaluation result of the battery package is determined to be a first-level failure. When the liquid loss is greater than the first critical liquid loss, and less than or equal to the second critical liquid loss, the evaluation result of the battery package is determined to be a second-level failure. In this way, by setting different levels of failure, the failure degree of the battery package is more finely divided, the evaluation result of the battery package is more accurate, and the practicality and effectiveness of the evaluation result of the battery package are improved.

[0142] Figure 5 Schematic diagram of the process of evaluating the battery packaging provided in this application Figure 3 ,like Figure 5 As shown, in this embodiment Figure 2 Based on the examples, the evaluation method of the battery package is described in detail.

[0143] When the fluid loss parameter includes the fluid loss amount, the critical parameter includes the critical fluid loss amount, and also includes the critical mass concentration, the method includes:

[0144] S501. Determine the mass concentration of the electrolyte at the seal after wet sealing according to the liquid loss.

[0145] After the mass concentration is determined, the mass concentration is used as one of the fluid loss parameters.

[0146] In a conventional concentration (1 mol / L) electrolyte, lithium hexafluorophosphate (LiPF 6 ) mass concentration is about 12.9%, and the mass concentration of the solvent is about 87.1%. The mass concentration c of the electrolyte at the seal corresponding to the loss of liquid A can be calculated based on the lithium hexafluorophosphate (LiPF 6) mass concentration, residual liquid coefficient, and evaporation amount of solvent in the electrolyte lost after the battery is wet-sealed.

[0147] Optionally, when determining the mass concentration of the electrolyte at the seal, the evaporation amount of the solvent in the electrolyte lost after the battery is wet-sealed and the residual liquid coefficient are obtained, and then the mass concentration is determined based on the liquid loss, the evaporation amount and the residual liquid coefficient.

[0148] For example, it is calculated by the following formula: c=k×A×12.9% / (k×A-bl), wherein k represents the residual liquid coefficient as described above, A represents the liquid loss of the battery electrolyte after wet sealing, and bl represents the evaporation amount of the solvent.

[0149] As described above, when the external environment is the same, the evaporation amount bl of the solvent is only related to the saturated vapor pressure. Optionally, when calculating the evaporation amount bl of the solvent, bl = evaporation rate × evaporation area × time. The calculation formula is: bl = M × (0.000352 + 0.000786V) × P × F × T. Among them, M is the molecular weight of the liquid, and the average molar mass of the electrolyte is taken here, with the unit of g / mol (grams per mole). Among them, V represents the air flow rate on the surface of the evaporating liquid, in m / s, and its value can generally be 0.2m / s~0.5m / s, and the preferred value can be 0.35m / s. Among them, P represents the air pressure at the corresponding liquid temperature, in mmHg (millimeters of mercury), and the preferred value can be 160mmHg (21.325kPa). Among them, F represents the surface area of ​​the liquid evaporation surface, in m 2 (square meters), the preferred value can be the sealing surface area of ​​0.00317m 2 T is the evaporation time, in seconds, and preferably the sealing heating time is 8 seconds. According to the preferred values, the solvent evaporation amount of the electrolyte around the seal bl=0.070g can be calculated.

[0150] S502: When the mass concentration is greater than or equal to the critical mass concentration, determining that the evaluation result of the battery package is failure.

[0151] The critical mass concentration can be determined according to the critical liquid loss, or according to the packaging performance parameters of a large number of batteries, or according to actual needs, which is not limited in this embodiment. When determining the critical mass concentration according to the critical liquid loss, the critical liquid loss can be substituted into the formula c=k×A×12.9% / (k×A-bl) to obtain the critical mass concentration.

[0152] As described above, when the liquid loss A changes from small to large, there is a critical concentration of the electrolyte at the seal. Above the critical concentration, the seal will produce crystallization, causing poor packaging, and below the critical concentration, the packaging is good.

[0153] Therefore, when it is determined that the mass concentration is greater than or equal to the critical mass concentration, it is proved that crystallization may occur at the seal, causing poor packaging, and the corresponding evaluation result of the battery packaging is failure.

[0154] S503: When the mass concentration is less than the critical mass concentration, determine that the evaluation result of the battery packaging is safe.

[0155] As described above, when the liquid loss A changes from small to large, there is a critical concentration of the electrolyte at the seal. Above the critical concentration, the seal will produce crystallization, causing poor packaging, and below the critical concentration, the packaging is good.

[0156] Therefore, when it is determined that the mass concentration is less than the critical mass concentration, it is proved that the packaging at the seal is good, and the corresponding evaluation result of the battery packaging is safe.

[0157] The method provided in this embodiment determines the evaluation result of battery packaging by measuring the amount of electrolyte loss in the battery after wet sealing, without destroying the packaged soft-pack battery, thus reducing the cost of obtaining the packaging effect of the soft-pack battery. In addition, in terms of factors affecting packaging failure, the prediction of the influence of foreign matter residues such as electrolyte at the seal of the wet sealing process has been expanded, which is of great significance for ensuring the heat sealing effect.

[0158] In some embodiments, see also Figure 4 , the critical mass concentration includes a first critical mass concentration and a second critical mass concentration; the failure includes a first level failure and a second level failure.

[0159] When determining the evaluation results of the battery packaging effect, include:

[0160] Step 1: when the mass concentration is greater than or equal to the first critical mass concentration, determining that the evaluation result of the battery package is a first level failure.

[0161] As described above, it can be known that when the mass concentration is greater, the corresponding battery packaging effect is worse. When the mass concentration is smaller, the corresponding battery packaging effect is better. Therefore, when the mass concentration is greater than or equal to the first critical mass concentration, it is proved that the packaging is seriously bad, and the evaluation result of the corresponding battery packaging is the first level failure. The first level failure can be understood as a serious failure.

[0162] The first critical mass concentration can be obtained according to the packaging performance parameters of the packaged batteries. For example, the packaging performance parameters of a large number of batteries are obtained, and the first critical mass concentration is determined according to the packaging performance parameters. The packaging performance parameters are the packaging defect rate described above.

[0163] Step 2: When the mass concentration is less than the first critical mass concentration and greater than or equal to the second critical mass concentration, determining that the evaluation result of the battery package is a second level failure.

[0164] As described above, it can be known that when the mass concentration is greater, the corresponding battery packaging effect is worse. When the mass concentration is smaller, the corresponding battery packaging effect is better. Therefore, when the mass concentration is less than the first critical mass concentration and greater than or equal to the second critical mass concentration, it is proved that poor packaging occurs, and the evaluation result of the corresponding battery packaging is a second-level failure. The second-level failure can be understood as a failure or a common failure.

[0165] Step three: when the mass concentration is less than the second critical mass concentration, determining that the evaluation result of the battery packaging is safe.

[0166] As described above, it can be known that when the mass concentration is greater, the corresponding battery packaging effect is worse. When the mass concentration is smaller, the corresponding battery packaging effect is better. Therefore, when the mass concentration is less than the second critical mass concentration, it proves that the battery packaging effect is good, and the corresponding battery packaging evaluation result is safe.

[0167] The method provided in this embodiment further distinguishes different levels of failure when the evaluation result of the battery package is failure. By setting different levels of failure, the failure degree of the battery package is more finely divided, the evaluation result of the battery package is more accurate, and the practicality and effectiveness of the evaluation result of the battery package are improved.

[0168] In some embodiments, when the critical parameter includes a critical liquid loss amount, before the step of obtaining the liquid loss amount of the battery electrolyte after wet sealing, the battery packaging evaluation method further includes:

[0169] Step 1: Obtain the electrolyte loss of multiple batteries after wet sealing and the packaging performance parameters of multiple batteries after wet sealing.

[0170] In the battery packaging process, the battery is wet-sealed while Degas is performed, with a wet-sealing temperature of 170 degrees Celsius (℃), a heat preservation time of 8 seconds (s), and a pressure of 200 kilograms (kg). After the wet-sealing is completed, the air bag part is cut off, and then the battery is folded and hot-stamped to obtain the finished product.

[0171] For example, select a number of qualified finished batteries with liquid loss in the range of a-b, b-c, c-d, d-e, f-L0 and above L0. Disassemble the batteries, cut the seals of the wet seals, perform thickness tests and peel tests on the seals, observe and record the failure causes, peeling and sol states.

[0172] The seals cut from the air bag side of finished batteries with liquid loss a-b, b-c, c-d, d-e, f-L0 and above L0 were peeled off, and three types of poor wet sealing phenomena were found: unmelted glue penetration channel, local poor melting of glue and bubbles.

[0173] In detail, when the amount of liquid loss is between a and b, the packaging defect rate after disassembly is 75%, of which air bubble defect, adhesive melt defect, and unmelted adhesive penetrating channel account for 55.55%, 33.33%, and 11.11%, respectively.

[0174] When the amount of liquid loss is between b and c, the packaging defect rate after disassembly is 75%, of which air bubble defect, adhesive melt defect and unmelted adhesive penetrating channel account for 33.33%, 66.67% and 0% respectively.

[0175] When the amount of liquid loss is between c and d, the packaging defect rate after disassembly is 75%, of which air bubble defect, adhesive melt defect and unmelted adhesive penetrating channel account for 0%, 33.33% and 66.67% respectively.

[0176] When the liquid loss is between d and e, the packaging defect rate after disassembly is 45.45%, of which air bubble defect, adhesive melt defect and unmelted adhesive penetrating channel account for 40%, 40% and 20% respectively.

[0177] When the liquid loss is between e and f, the packaging defect rate after disassembly is 24.14%, of which air bubble defect, adhesive melt defect and unmelted adhesive penetrating channel account for 42.86%, 57.14% and 0% respectively.

[0178] When the amount of liquid loss is between f and L0, the defective rate of packaging after disassembly is 28.57%, of which air bubble defect, adhesive melt defect, and unmelted adhesive penetrating channel account for 100%, 0%, and 0%, respectively.

[0179] When the liquid loss is less than L0, the packaging defective rates are 75%, 46.67% and 22.22% under the liquid loss ranges of a~b, b~d and d~L0, respectively.

[0180] Step 2: determining the critical liquid loss amount according to the electrolyte loss amount of the multiple batteries after wet sealing and the packaging performance parameters of the multiple batteries after wet sealing.

[0181] As shown in the above example, when the amount of liquid loss is less than L0, the packaging defective rates under the conditions of a-b, b-d and d-L0 are 75%, 46.67% and 22.22% respectively. It can be seen that as the amount of liquid loss decreases, the defective rate increases. The probability of packaging defective is very high when the amount of liquid loss is between a and d. A total of 67 batteries were disassembled, and 28 batteries were defective, of which 46.43% (13 pcs) were defective due to bubbles, 39.29% (11 pcs) were defective due to melted glue, and 14.29% (4 pcs) were due to unmelted glue penetration. When the amount of liquid loss is greater than L0, no packaging defect occurs.

[0182] At this time, L0 can be defined as the critical liquid loss amount. When the liquid loss amount obtained in step S201 is less than or equal to L0, the evaluation result of the battery package is determined to be failure. When the liquid loss amount obtained in step S201 is greater than L0, the evaluation result of the battery package is determined to be safe.

[0183] The method provided in this embodiment can be executed only once to save resources. The method provided in this embodiment can also be executed multiple times according to actual needs to more flexibly adapt to actual needs.

[0184] The method provided in this embodiment determines the critical liquid loss amount according to the actual packaging results of multiple batteries. The determined critical liquid loss amount is more real and reliable, and can indirectly improve the accuracy and reliability of the evaluation results of battery packaging.

[0185] In some embodiments, when the critical parameter includes a critical mass concentration, before the step of obtaining the amount of liquid loss of the battery electrolyte after wet sealing, the battery packaging evaluation method further includes:

[0186] Step 1: Obtain the electrolyte loss of multiple batteries after wet sealing and the packaging performance parameters of multiple batteries after wet sealing.

[0187] In the battery packaging process, the battery is wet-sealed while Degas is performed, with a wet-sealing temperature of 170 degrees Celsius (℃), a heat preservation time of 8 seconds (s), and a pressure of 200 kilograms (kg). After the wet-sealing is completed, the air bag part is cut off, and then the battery is folded and hot-stamped to obtain the finished product.

[0188] For example, select a number of qualified finished batteries with liquid loss in the range of a-b, b-c, c-d, d-e, f-L0 and above L0. Disassemble the batteries, cut the seals of the wet seals, perform thickness tests and peel tests on the seals, observe and record the failure causes, peeling and sol states.

[0189] The seals cut from the air bag side of finished batteries with liquid loss a-b, b-c, c-d, d-e, f-L0 and above L0 were peeled off, and three types of poor wet sealing phenomena were found: unmelted glue penetration channel, local poor melting of glue and bubbles.

[0190] In detail, when the amount of liquid loss is between a and b, the packaging defect rate after disassembly is 75%, of which air bubble defect, adhesive melt defect, and unmelted adhesive penetrating channel account for 55.55%, 33.33%, and 11.11%, respectively.

[0191] When the amount of liquid loss is between b and c, the packaging defect rate after disassembly is 75%, of which air bubble defect, adhesive melt defect and unmelted adhesive penetrating channel account for 33.33%, 66.67% and 0% respectively.

[0192] When the amount of liquid loss is between c and d, the packaging defect rate after disassembly is 75%, of which air bubble defect, adhesive melt defect and unmelted adhesive penetrating channel account for 0%, 33.33% and 66.67% respectively.

[0193] When the liquid loss is between d and e, the packaging defect rate after disassembly is 45.45%, of which air bubble defect, adhesive melt defect and unmelted adhesive penetrating channel account for 40%, 40% and 20% respectively.

[0194] When the liquid loss is between e and f, the packaging defect rate after disassembly is 24.14%, of which air bubble defect, adhesive melt defect and unmelted adhesive penetrating channel account for 42.86%, 57.14% and 0% respectively.

[0195] When the amount of liquid loss is between f and L0, the defective rate of packaging after disassembly is 28.57%, of which air bubble defect, adhesive melt defect, and unmelted adhesive penetrating channel account for 100%, 0%, and 0%, respectively.

[0196] When the liquid loss is less than L0, the packaging defective rates are 75%, 46.67% and 22.22% under the liquid loss ranges of a~b, b~d and d~L0, respectively.

[0197] Step 2: for each battery among the multiple batteries, determine the mass concentration of the electrolyte at the battery seal according to the amount of electrolyte loss after the battery is wet sealed.

[0198] For example, for each of the qualified finished batteries with liquid loss amounts between a~b, b~c, c~d, d~e, f~L0 and above L0, the mass concentration of the electrolyte at the seal is determined according to the liquid loss amount.

[0199] Alternatively, the mass concentration may be determined according to the formula c=k×A×12.9% / (k×A-bl), wherein k represents the residual liquid coefficient as described above, A represents the liquid loss, and bl represents the evaporation amount of the solvent.

[0200] Step three, determining the critical mass concentration according to the mass concentration of the electrolyte at the seal of each battery in the multiple batteries and the packaging performance parameters of each battery after wet sealing.

[0201] As in the above example, when the packaging failure rates are 75%, 46.67% and 22.22% respectively under the loss of liquid in a-b, b-d and d-L0, the packaging effect of the battery is good. The mass concentration of the electrolyte at the battery seal corresponding to the packaging failure rates of 75%, 46.67% and 22.22% is obtained, which is the critical mass concentration.

[0202] Optionally, when the liquid loss is less than L0, the packaging defective rates under the liquid loss a-b, b-d and d-L0 are 75%, 46.67% and 22.22% respectively. At this time, the packaging effect of the battery is good. Substituting the liquid loss L0 into the formula c=k×A×12.9% / (k×A-bl), the critical mass concentration can be determined.

[0203] The method provided in this embodiment can be executed only once to save resources. The method provided in this embodiment can also be executed multiple times according to actual needs to more flexibly adapt to actual needs.

[0204] The method provided in this embodiment determines the critical mass concentration based on the actual packaging results of multiple batteries. The determined critical mass concentration is more real and reliable, and can indirectly improve the accuracy and reliability of the evaluation results of battery packaging.

[0205] Figure 6 A schematic diagram of the structure of the battery packaging evaluation device provided in this application, such as Figure 6 As shown, the battery packaging evaluation device 60 provided in this embodiment includes:

[0206] The processing module 601 is used to determine whether the evaluation result of the battery packaging is failure or safety according to the liquid loss parameter and critical parameter of the battery electrolyte after wet sealing; wherein, when the liquid loss parameter includes the liquid loss amount, the critical parameter includes the critical liquid loss amount, or also includes the critical mass concentration; wherein, when the liquid loss parameter includes the mass concentration of the electrolyte at the seal after wet sealing, the critical parameter includes the critical mass concentration, or also includes the critical liquid loss amount.

[0207] In a possible implementation, the battery packaging evaluation device 60 also includes an acquisition module 602. When the liquid loss parameter includes the liquid loss amount, the acquisition module 602 is used to determine the liquid loss amount of the battery electrolyte after wet sealing based on the first weight of the battery after electrolyte is injected, the length of the air bag generated by the battery packaging, the width of the air bag, the density of the aluminum-plastic film surface and the second weight of the finished battery.

[0208] In a possible implementation, the acquisition module 602 is used to: determine a reference weight based on the length of the air bag generated by the battery packaging, the width of the air bag and the density of the aluminum-plastic film surface; and determine the amount of electrolyte loss of the battery after wet sealing based on the first weight, the second weight and the reference weight.

[0209] In a possible implementation, the acquisition module 602 is used to determine the reference weight according to the formula B=Wq×Lq×ρ; wherein B represents the reference weight, Wq represents the width of the airbag, Lq represents the length of the airbag, and ρ represents the density of the aluminum-plastic film surface.

[0210] In one possible implementation, the acquisition module 602 is used to determine the amount of liquid loss of the battery electrolyte after wet sealing according to the formula A=m1-m2-B; wherein A represents the amount of liquid loss of the battery electrolyte after wet sealing, m1 represents the first weight, m2 represents the second weight, and B represents the reference weight.

[0211] In a possible implementation, when the critical parameter includes a critical liquid loss amount, the processing module 601 is used to: when the liquid loss amount is less than or equal to the critical liquid loss amount, determine that the evaluation result of the battery package is failure; when the liquid loss amount is greater than the critical liquid loss amount, determine that the evaluation result of the battery package is safe.

[0212] In a possible implementation, the critical liquid loss amount includes a first critical liquid loss amount and a second critical liquid loss amount, the failure includes a first level failure and a second level failure, and the processing module 601 is used to: when the liquid loss amount is less than or equal to the first critical liquid loss amount, determine that the evaluation result of the battery package is a first level failure; when the liquid loss amount is greater than the first critical liquid loss amount and less than or equal to the second critical liquid loss amount, determine that the evaluation result of the battery package is a second level failure.

[0213] In a possible implementation, the processing module 601 is used to: when the liquid loss amount is greater than the second critical liquid loss amount, determine that the evaluation result of the battery package is safe.

[0214] In one possible implementation, when the liquid loss parameter includes mass concentration, the processing module 601 is used to: when the mass concentration is greater than or equal to the critical mass concentration, determine that the evaluation result of the battery package is failure; when the mass concentration is less than the critical mass concentration, determine that the evaluation result of the battery package is safe.

[0215] In one possible implementation, the critical mass concentration includes a first critical mass concentration and a second critical mass concentration; the failure includes a first-level failure and a second-level failure; the processing module 601 is used to: when the mass concentration is greater than or equal to the first critical mass concentration, determine that the evaluation result of the battery package is a first-level failure; when the mass concentration is less than the first critical mass concentration and greater than or equal to the second critical mass concentration, determine that the evaluation result of the battery package is a second-level failure.

[0216] In a possible implementation, the processing module 601 is used to: when the mass concentration is less than the second critical mass concentration, determine that the evaluation result of the battery package is safe.

[0217] In a possible implementation, when the fluid loss parameter includes the fluid loss amount, and the critical parameter also includes the critical mass concentration, the processing module 601 is used to: determine the mass concentration of the electrolyte at the seal after wet sealing according to the fluid loss amount, the evaporation amount of the solvent in the electrolyte lost after the battery is wet sealed, and the residual liquid coefficient, and take the mass concentration as one of the fluid loss parameters.

[0218] In a possible implementation, the processing module 601 is used to determine the mass concentration according to the formula c=k×A×12.9% / (k×A-bl); wherein c represents the mass concentration, A represents the liquid loss, k represents the residual liquid coefficient, and bl represents the evaporation amount.

[0219] In a possible implementation, when the critical parameter includes a critical liquid loss amount, the acquisition module 601 is used to: obtain the liquid loss amount of the electrolyte of the multiple batteries after wet sealing and the packaging performance parameters of the multiple batteries after wet sealing; determine the critical liquid loss amount according to the liquid loss amount of the electrolyte of the multiple batteries after wet sealing and the packaging performance parameters of the multiple batteries after wet sealing.

[0220] In a possible implementation, when the critical parameter includes a critical mass concentration, the acquisition module 601 is used to: obtain the amount of electrolyte loss of multiple batteries after wet sealing and the packaging performance parameters of multiple batteries after wet sealing; for each battery in the multiple batteries, determine the mass concentration of the electrolyte at the battery seal according to the amount of electrolyte loss of the battery after wet sealing; determine the critical mass concentration according to the mass concentration of the electrolyte at the seal of each battery in the multiple batteries and the packaging performance parameters of each battery after wet sealing.

[0221] The battery package evaluation device 60 provided in this embodiment can execute the battery package evaluation method provided in the above method embodiment, and its implementation principle and technical effect are similar, which will not be described in detail in this embodiment.

[0222] Figure 7 This is a schematic diagram of the structure of the electronic device provided in this application. Figure 7 As shown, the electronic device 70 provided in this embodiment includes: at least one processor 701 and a memory 702. Optionally, the device 70 further includes a communication component 703. The processor 701, the memory 702 and the communication component 703 are connected via a bus 704.

[0223] In a specific implementation process, at least one processor 701 executes the computer-executable instructions stored in the memory 702, so that at least one processor 701 executes the above method.

[0224] The specific implementation process of the processor 701 can be found in the above method embodiment, and its implementation principle and technical effect are similar, so this embodiment will not be repeated here.

[0225] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the invention may be directly implemented as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0226] The memory may include a high-speed memory (Random Access Memory, RAM), and may also include a non-volatile memory (Non-volatile Memory, NVM), such as at least one disk memory.

[0227] The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the bus in the drawings of the present application is not limited to only one bus or one type of bus.

[0228] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0229] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above method is implemented.

[0230] The above-mentioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general or special-purpose computer.

[0231] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (Application Specific Integrated Circuits, referred to as: ASIC). Of course, the processor and the readable storage medium can also exist in the device as discrete components.

[0232] The division of units is only a logical function division, and there may be other divisions in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0233] The units described as segmented components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0234] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0235] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0236] Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[0237] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for evaluating battery packaging, characterized in that: include: Determine whether the evaluation result of the battery packaging is failure or safety based on the liquid loss parameters and critical parameters of the battery electrolyte after wet sealing; Wherein, when the fluid loss parameter includes the fluid loss amount, the critical parameter includes the critical fluid loss amount, or also includes the critical mass concentration; Wherein, when the fluid loss parameter includes the mass concentration of the electrolyte at the seal after wet sealing, the critical parameter includes the critical mass concentration, or also includes the critical fluid loss amount.

2. The method according to claim 1, characterized in that When the fluid loss parameter includes the amount of fluid loss, the method further comprises: The amount of electrolyte loss in the battery after wet sealing is determined based on the first weight of the battery after electrolyte is injected, the length of the air pocket generated by the battery packaging, the width of the air pocket, the density of the aluminum-plastic film surface and the second weight of the finished battery.

3. The method according to claim 2, characterized in that Determining the amount of electrolyte loss after wet sealing of the battery according to the first weight of the battery after the electrolyte is injected, the length of the air pocket generated by the battery packaging, the width of the air pocket, the density of the aluminum-plastic film surface and the second weight of the finished battery includes: Determining a reference weight according to the length of the air pocket generated by the battery packaging, the width of the air pocket and the density of the aluminum-plastic film surface; The amount of electrolyte loss in the battery after wet sealing is determined according to the first weight, the second weight and the reference weight.

4. The method according to claim 3, characterized in that Determining the reference weight according to the length of the air bag generated by the battery packaging, the width of the air bag and the density of the aluminum-plastic film surface includes: The reference weight is determined according to the formula B=Wq×Lq×ρ, wherein B represents the reference weight, Wq represents the width of the air bag, Lq represents the length of the air bag, and ρ represents the density of the aluminum-plastic film surface.

5. The method according to claim 3, characterized in that: Determining the amount of electrolyte loss of the battery after wet sealing according to the first weight, the second weight and the reference weight includes: According to the formula A=m1-m2-B, the amount of electrolyte loss of the battery after wet sealing is determined; wherein A represents the amount of electrolyte loss of the battery after wet sealing, m1 represents the first weight, m2 represents the second weight, and B represents the reference weight.

6. The method according to claim 1, characterized in that When the fluid loss parameter includes the fluid loss amount, determining whether the evaluation result of the battery package is failure or safety according to the fluid loss parameter and the critical parameter includes: When the liquid loss amount is less than or equal to the critical liquid loss amount, determining that the evaluation result of the battery package is failure; When the liquid loss amount is greater than the critical liquid loss amount, the evaluation result of the battery package is determined to be safe.

7. The method according to claim 6, characterized in that The critical liquid loss includes a first critical liquid loss and a second critical liquid loss, the failure includes a first level failure and a second level failure, and when the liquid loss is less than or equal to the critical liquid loss, determining that the evaluation result of the battery package is a failure includes: When the liquid loss amount is less than or equal to the first critical liquid loss amount, determining that the evaluation result of the battery package is a first level failure; When the liquid loss amount is greater than the first critical liquid loss amount and less than or equal to the second critical liquid loss amount, it is determined that the evaluation result of the battery package is a second level failure.

8. The method according to claim 7, characterized in that When the liquid loss amount is greater than the critical liquid loss amount, determining that the evaluation result of the battery package is safe includes: When the liquid loss amount is greater than the second critical liquid loss amount, it is determined that the evaluation result of the battery package is safe.

9. The method according to claim 1, characterized in that: When the liquid loss parameter includes mass concentration, determining whether the evaluation result of the battery package is failure or safety according to the liquid loss parameter and the critical parameter includes: When the mass concentration is greater than or equal to the critical mass concentration, determining that the evaluation result of the battery package is failure; When the mass concentration is less than the critical mass concentration, it is determined that the evaluation result of the battery packaging is safe.

10. The method according to claim 9, characterized in that The critical mass concentration includes a first critical mass concentration and a second critical mass concentration; the failure includes a first level failure and a second level failure; When the mass concentration is greater than or equal to the critical mass concentration, determining that the evaluation result of the battery package is failure includes: When the mass concentration is greater than or equal to the first critical mass concentration, determining that the evaluation result of the battery package is a first level failure; When the mass concentration is less than the first critical mass concentration and greater than or equal to the second critical mass concentration, it is determined that the evaluation result of the battery package is a second level failure.

11. The method according to claim 10, characterized in that When the mass concentration is less than or equal to the critical mass concentration, determining that the evaluation result of the battery package is safe includes: When the mass concentration is less than the second critical mass concentration, it is determined that the evaluation result of the battery package is safe.

12. The method according to claim 9, characterized in that When the fluid loss parameter includes the fluid loss amount, and the critical parameter also includes the critical mass concentration, the method further includes: According to the liquid loss amount, the evaporation amount of the solvent in the electrolyte lost after the battery is wet sealed, and the residual liquid coefficient, the mass concentration of the electrolyte at the seal after wet sealing is determined, and the mass concentration is used as one of the liquid loss parameters.

13. The method according to claim 12, characterized in that Determining the mass concentration of the battery electrolyte after wet sealing according to the liquid loss, the evaporation amount of the solvent in the electrolyte lost after the battery is wet sealed, and the residual liquid coefficient includes: The mass concentration is determined according to the formula c=k×A×12.9% / (k×A-bl); wherein c represents the mass concentration, A represents the liquid loss, k represents the residual liquid coefficient, and bl represents the evaporation amount.

14. The method according to any one of claims 1 to 13, characterized in that: When the critical parameter includes a critical liquid loss amount, before obtaining the liquid loss amount of the battery electrolyte after wet sealing, the method further includes: Obtaining electrolyte loss of multiple batteries after wet sealing and packaging performance parameters of multiple batteries after wet sealing; The critical liquid loss amount is determined according to the electrolyte loss amount of the multiple batteries after wet sealing and the packaging performance parameters of the multiple batteries after wet sealing.

15. The method according to any one of claims 1 to 13, characterized in that: When the critical parameter includes a critical mass concentration, before obtaining the amount of electrolyte loss of the battery after wet sealing, the method further includes: Obtaining electrolyte loss of multiple batteries after wet sealing and packaging performance parameters of multiple batteries after wet sealing; For each of the plurality of batteries, determining the mass concentration of the electrolyte at the battery seal according to the amount of electrolyte loss of the battery after wet sealing; The critical mass concentration is determined according to the mass concentration of the electrolyte at the seal of each battery in the plurality of batteries and the packaging performance parameters of each battery after wet sealing.

16. A battery packaging evaluation device, characterized in that: include: A processing module, used to determine whether the evaluation result of the battery packaging is failure or safety according to the liquid loss parameter and critical parameter of the battery electrolyte after wet sealing; Wherein, when the fluid loss parameter includes the fluid loss amount, the critical parameter includes the critical fluid loss amount, or also includes the critical mass concentration; Wherein, when the fluid loss parameter includes mass concentration, the critical parameter includes critical mass concentration, or also includes critical fluid loss amount.

17. An electronic device, characterized in that: include: Memory, processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method according to any one of claims 1 to 15.

18. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 15 when executed by a processor.

19. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 15 when executed by a processor.

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