Battery pack and electric device

Abstract

The application relates to the technical field of batteries, and discloses a battery pack and an electric device, the battery pack comprising: a shell, an insulating layer; an outer surface of one side of the shell is defined as an opening surface, and the insulating layer is at least partially penetrated in a region of the opening surface to form an opening part; adjacent conductor plates are arranged in parallel and are spaced apart from each other; in a direction perpendicular to the opening surface, the area of the opening part is defined as s1, and the area of a covered part is defined as s2; the minimum distance between the outer surface of the shell and the adjacent conductor plate, which is overlapped with the projection of the opening part and is close to the adjacent conductor plate, is defined as d1, and the thickness of the insulating layer in the covered part is defined as d2; and the following formula is satisfied: 8.86E-10 <= 100*k1*s1 / d1 + k2*s2 / d2 <= 4.55E-08, unit: F. The battery pack provided by the application can reasonably control the size of the opening part, ensure the precision of electrolyte leakage detection, avoid the occurrence of charging interruption, and ensure the accuracy of whole vehicle leakage detection.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery pack and an electrical device. Background Art

[0002] The battery shell is typically made of metal, such as aluminum. To insulate the battery shell, an insulating film is typically wrapped around the outer surface. In related technologies, batteries must be filled with electrolyte after assembly. Due to processing errors, sealing defects, and other factors, there is a certain probability of electrolyte leakage after the battery is filled. Batteries with leakage need to be identified promptly to prevent defective products from entering the market.

[0003] However, when the insulating film wraps around the battery, it hinders electrolyte leakage detection. Providing openings in the insulating film can greatly improve battery leakage detection efficiency. However, openings in the insulating film can easily cause charging interruptions, affecting the user's charging experience and increasing safety risks. They can also affect the accuracy of vehicle leakage detection. Summary of the Invention

[0004] In view of this, the present invention provides a battery pack and an electrical device to solve the problem that the enlarged opening of the insulating film easily leads to charging interruption and affects the accuracy of vehicle leakage detection.

[0005] In a first aspect, the present invention provides a battery pack, comprising:

[0006] A battery cell, comprising a shell and an insulating layer covering the outer surface of the shell;

[0007] The outer surface of one side of the housing is defined as an opening surface, the area where the insulating layer covers the opening surface at least partially penetrates through the opening portion, and the area where the insulating layer covers the opening surface and is located outside the opening portion forms a covering portion;

[0008] The battery pack further includes: an adjacent conductor plate adjacent to the opening surface, with an insulating layer interposed between the adjacent conductor plate and the opening surface;

[0009] In the direction perpendicular to the opening surface, the area of ​​the opening is defined as s1, and the area of ​​the covering is defined as s2. The minimum distance between the outer surface of the shell overlapping with the projection of the opening and close to the adjacent conductor plate and the adjacent conductor plate is defined as d1, and the thickness of the insulating layer in the covering is defined as d2. The following conditions are satisfied:

[0010] 8.86E-10≤100·k1·s1 / d1+k2·s2 / d2≤4.55E-08, unit: F;

[0011] Wherein, k1 is the dielectric constant of the structural adhesive layer bonded between the outer surface of the housing and the adjacent conductor plate at 40°C, and k2 is the dielectric constant of the insulation layer at 40°C;

[0012] The value range of k1 is 3.01E-11≤k1≤3.81E-11; the value range of k2 is 2.66E-11≤k2≤3.01E-11, unit: F / m.

[0013] The above-described technical solution has the following beneficial effects: Because the insulating layer covering the opening surface has an opening, the accuracy of electrolyte leakage detection is ensured while the opening size of the insulating layer is rationally set, thereby controlling the leakage current between the battery housing and adjacent conductors, reducing the occurrence of charging interruptions and improving the accuracy of leakage detection for the entire vehicle. When the total area of ​​the opening surface is constant, the area of ​​the covering portion, s2, is indirectly determined by rationally setting the area of ​​the opening, s1. Furthermore, by rationally selecting d1 and d2, the upper limit of k1·s1 / d1+k2·s2 / d2 can be guaranteed, thereby controlling the leakage current between the battery housing and adjacent conductor plates within a safe range.

[0014] In a second aspect, the present invention further provides an electrical device comprising the battery pack as described above.

[0015] Since the electrical device includes a battery pack and has the same effect as the battery pack, it will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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.

[0017] Figure 1 A schematic diagram of a battery cell with an opening located on the side of the battery cell according to the present invention;

[0018] Figure 2 Schematic diagram of a battery cell with an opening located on the top surface of the present invention;

[0019] Figure 3 A schematic diagram of a battery cell with an opening located at the bottom surface of the present invention;

[0020] Figure 4 is an enlarged schematic diagram of a battery cell and adjacent metal plates of the present invention;

[0021] Description of reference numerals:

[0022] 100, battery cell; 1, housing; 11, opening surface; 12, injection hole; 2, insulation layer; 21, opening; 22, covering portion; 3, structural adhesive layer;

[0023] 200. Adjacent conductor plates. DETAILED DESCRIPTION

[0024] 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.

[0025] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0027] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] The battery casing is typically made of metal, such as aluminum or steel. The casing houses the battery cell, which consists of the positive and negative electrodes and the separator between them, wound or stacked together. The cell serves as the smallest independent charge and discharge unit housed within the battery casing and electrically connected to the electrode assembly mounted on the casing. To insulate the battery casing, an insulating layer is typically applied to the outer surface of the casing.

[0029] In related technologies, batteries need to be injected with electrolyte after assembly. Due to processing errors, sealing defects and other reasons, there is a certain probability of electrolyte leakage after the battery is injected. Batteries with leakage need to be identified in a timely manner to avoid defective products from entering the market.

[0030] However, when the insulating layer wraps the battery, it will hinder the detection of electrolyte leakage. If an opening is set in the insulating layer, the efficiency of battery leakage detection can be greatly improved. When the battery shell is wrapped with an insulating layer and the insulating layer has no opening, the electrolyte will remain between the battery shell and the insulating layer after leakage, and will not overlap with the box (or cold plate). No circuit is formed. At this time, it is impossible to detect whether the electrolyte has leaked through the insulation detection device. When the battery shell is wrapped with an insulating layer and there is a gap in the insulating layer, the larger the gap, the greater the probability that the leaked electrolyte will overlap with the box (or cold plate) after leakage. At this time, a loop is formed through the battery shell-electrolyte-box / cold plate. At this time, detection by the insulation detection device will sound an alarm, and the insulation detection device can be used to detect whether the electrolyte has leaked.

[0031] However, the openings in the insulation layer should not be too large. Larger openings in the insulation layer can lead to excessive leakage current during slow charging. The RCD can detect this and cut off the high-voltage circuit, which is often said to cause the RCD to trip, resulting in charging interruption. RCD refers to a residual current device, and the relevant standards require that the RCD detection threshold be 30mA.

[0032] Depending on the location of the insulation layer opening, excessive leakage current can occur between the battery and the base plate, between the battery and the metal plate of the box beam, or between the battery and the metal plate of the liquid cooling plate. Excessive leakage current can easily cause charging interruptions, affecting the user's charging experience and increasing safety risks. It can also affect the accuracy of vehicle leakage detection.

[0033] The battery pack provided by the embodiments of the present invention reasonably sets the opening size on the insulating layer while ensuring the accuracy of electrolyte leakage detection, thereby controlling the leakage current value between the battery shell and the adjacent conductor, reducing the occurrence of charging interruptions, and improving the accuracy of vehicle leakage detection.

[0034] The following combination Figures 1 to 4 , describing embodiments of the present invention.

[0035] According to an embodiment of the present invention, on one hand, a battery pack is provided, comprising:

[0036] The battery cell 100 includes a shell 1 and an insulating layer 2 covering the outer surface of the shell 1;

[0037] The outer surface of one side of the housing 1 is defined as an opening surface 11. The area of ​​the insulating layer 2 covering the opening surface 11 at least partially penetrates through the opening portion 21 to form a covering portion 22.

[0038] The battery pack further includes: adjacent conductive plates 200 adjacent to the opening surface 11, with an insulating layer 2 interposed between the adjacent conductive plates 200 and the opening surface 11;

[0039] In a direction perpendicular to the opening surface 11, the area of ​​the opening 21 is defined as s1, and the area of ​​the covering portion 22 is defined as s2. The minimum distance between the outer surface of the housing 1 overlapping with the projection of the opening 21 and close to the adjacent conductor plate 200 and the adjacent conductor plate 200 is defined as d1. The thickness of the insulating layer 2 at the covering portion 22 is defined as d2. The following conditions are satisfied:

[0040] 8.86E-10≤100·k1·s1 / d1+k2·s2 / d2≤4.55E-08, unit: F;

[0041] When the battery is running or charging, the temperature rises. k1 is the dielectric constant of the structural adhesive layer 3 bonded between the outer surface of the housing 1 and the adjacent conductive plate 200 at 40°C, and k2 is the dielectric constant of the insulating layer 2 at 40°C.

[0042] k1=ε0·εr1, ε0 is the dielectric constant of vacuum, εr1 is the dielectric constant of the structural adhesive layer 3;

[0043] K2=ε0·εr2, ε0 is the dielectric constant of vacuum, and εr2 is the dielectric constant of the insulating layer 2.

[0044] In this embodiment, the material of the structural adhesive layer 3 is selected from organic silicon structural adhesive, polyurethane or epoxy resin; the material of the insulating layer 2 is selected from PP film, PC film, PET film or PI film.

[0045] Among them, the test method of εr can be carried out in accordance with the International Electrotechnical Commission standard IEC 62631-2-1:2018. The test equipment used can be an LCR tester, and the test temperature is 40°C.

[0046] d1 is adjusted based on the space requirements and fixing strength requirements of the battery cell in the battery pack. The range of d1 is 1.00E-03≤d1≤5.00E-03, unit: m.

[0047] Furthermore, the preferred range of d1 is 2.00E-03≤d1≤4.00E-03, unit: m.

[0048] d2 is the thickness of the insulating layer at the covering portion, the range of d2 is 1.00E-5≤d2≤2.50E-04, unit: m.

[0049] Furthermore, the preferred range of d2 is 5.00E-5≤d2≤2.50E-04, unit: m.

[0050] Furthermore, the preferred range of d2 is 8.00E-5≤d2≤1.10E-04, unit: m.

[0051] In some embodiments, the value range of k1 is 3.01E-11≤k1≤3.81E-11, unit: F / m; the value range of k2 is 2.66E-11≤k2≤3.01E-11, unit: F / m.

[0052] In this embodiment, the area where the insulating layer 2 covers the opening surface 11 is at least partially penetrated to form an opening portion 21, and the opening portion 21 can expose the outer surface of the shell 1; and the area where the insulating layer 2 covers the opening surface 11 and is located outside the opening portion 21 forms a covering portion 22, and the covering portion 22 can wrap the area outside the opening portion 21 to prevent the outer surface of the shell 1 in this area from being exposed.

[0053] It should be noted that the area covered by the insulating layer 2 on the opening surface 11 at least partially penetrates to form an opening portion 21, wherein the number of the opening portions 21 can be one or more. When the number of the opening portions 21 is multiple, in the direction perpendicular to the opening surface 11, the area s1 of the opening portion 21 is the sum of the areas of the multiple opening portions 21.

[0054] In this embodiment, adjacent conductor plates 200 are parallel to the opening surface 11 and spaced apart. The adjacent conductor plates 200 can be metal plates such as the battery box bottom plate, side plate, liquid cooling plate, or a metal flat plate of a box beam.

[0055] The dielectric constant is a physical quantity that measures a substance's response to an electric field. It increases with the molecular dipole moment and polarizability. In other words, the dielectric constant is related to the specific material of the insulating medium between two adjacent conductors. For example, if air is placed between two adjacent conductors, the dielectric constant is 1. Similarly, if polyvinyl chloride is used as the insulating medium between two adjacent conductors, the dielectric constant ranges from 3.1 to 3.5.

[0056] In this embodiment, both k1 and k2 are related to the dielectric constant of the insulating medium interposed between the adjacent conductive plates 200 and the opening surface 11. Specifically, k1 corresponding to the opening 21 region may be the product of the dielectric constant of the structural adhesive layer 3 and the dielectric constant of a vacuum, while k2 corresponding to the covering portion 22 region may be the product of the dielectric constant of the insulating layer 2 and the dielectric constant of a vacuum.

[0057] The battery pack provided by the embodiment of the present invention has an opening portion 21 formed on the insulating layer 2 covering the opening surface 11. While ensuring the accuracy of electrolyte leakage detection, the opening size on the insulating layer is reasonably set, thereby controlling the leakage current value between the battery shell and the adjacent conductor, reducing the occurrence of charging interruptions, and improving the accuracy of vehicle leakage detection.

[0058] In addition, by reasonably controlling the size of the opening 21 and the leakage current value between the battery shell and the adjacent conductor plate 200 , the safety performance of the entire battery pack can be improved to a certain extent.

[0059] The minimum distance d1 between the outer surface of the housing 1 overlapping with the projection of the opening 21 and the adjacent conductive plate 200 is greater than the minimum distance d2 between the covering portion 22 and the adjacent conductive plate 200 .

[0060] In this embodiment, when the total area of ​​the opening surface 11 is constant, by reasonably setting the area s1 of the opening portion 21 and by reasonably selecting d1 and d2, a reasonable range of k1·s1 / d1+k2·s2 / d2 can be ensured, thereby controlling the leakage current value between the battery shell and the adjacent conductor plate 200 within a safe range.

[0061] In some embodiments, 0.22≤s1 / (s1+s2)≤0.77, the value range of s1 is: 6.72E-04≤s1≤1.16E-02, unit: m 2 The value range of s2 is: 1.38E-03≤s2≤1.17E-02, unit: m 2 .

[0062] Additionally, by providing an opening 21 in the insulating layer 2, the bonding strength of the battery can be increased. After the battery is placed in the box, in order to ensure that the battery is firmly fixed, the battery is often bonded to the bottom plate, and the adjacent batteries can also be bonded. Taking the bonding of the battery to the bottom plate as an example, since the outer surface of the shell is wrapped with an insulating layer, the insulating layer is actually bonded to the bottom plate, which leads to a certain risk of detachment between the battery and the bottom plate. By providing an opening in the insulating layer, the shell in the opening area is directly bonded to the bottom plate, thereby increasing the bonding strength of the battery and ensuring the fixing effect.

[0063] It should be noted that since the electrolyte has conductive properties, after the battery leaks, the traces of the leakage also have conductive properties. By providing an opening on the insulating layer, the leakage detection device can facilitate detection using the circuit formed by the leakage. The circuit is generally formed in the following manner: battery shell-leaked electrolyte-battery pack box or cold plate, thereby ensuring that the battery with electrolyte leakage is detected; the specific detection method can be to detect the resistance value between the battery high voltage and the battery pack shell through insulation detection. Because the electrolyte is conductive, a resistance value that is too low indicates leakage.

[0064] In addition, when conducting leakage detection, the specific application of the national standard for insulation testing can refer to GB 18384-2020 "Safety Requirements for Electric Vehicles" and obtain corresponding test results.

[0065] The specific safety testing method is as follows: Each group of 100 batteries is tested with different control groups. Batteries with different window sizes are assembled into a pack. The pack is then slow-charged. The PE line in the slow-charge charger is disconnected, and the voltage between the vehicle body / battery pack housing and the bottom surface is measured. A leakage detection rate of 80% is acceptable.

[0066] Since the safety voltage for the human body is 36V, when the voltage between two points is ≥36V, it means there is a safety risk of electric shock; when the voltage between two points is <36V, there is no risk of electric shock.

[0067] The specific effects of the battery pack provided by the present invention are verified below in combination with several experimental examples and comparative examples, as shown in Table 1 below.

[0068] Table 1

[0069]

[0070]

[0071] Combined with the above table, the following explanations are given:

[0072] k1 is the dielectric constant of the structural adhesive layer 3 bonded between the outer surface of the housing 1 and the adjacent conductive plate 200. Depending on the material of the structural adhesive layer 3 selected, through experiments, among structural adhesive layers 3 made of various materials, the upper limit of k1 is 3.81E-11, and the lower limit of k1 is 3.01E-11. The unit is F / m.

[0073] k2 is the dielectric constant of the insulating layer 2. Depending on the material of the insulating layer 2, through experiments, in the insulating layer 2 of various materials, the upper limit of k2 is 3.01E-11, and the lower limit of k2 is 2.66E-11, unit: F / m.

[0074] The upper limit of the area s1 of the opening 21 is 1.16E-02m 2 The lower limit is 6.72E-04m 2 The upper limit of the area s2 of the covering portion 22 is 1.17E-02m 2 The lower limit is 1.38E-03m 2 .

[0075] The minimum distance between the outer surface of the housing 1 where the projections of the openings 21 overlap and are close to the adjacent conductor plate 200 and the adjacent conductor plate 200 is d1, the upper limit of d1 is 5.00E-03, the lower limit is 1.00E-03, and the unit is m.

[0076] The upper limit of the thickness d2 of the insulating layer 2 at the covering portion 22 is 2.50E-04, and the lower limit is 5.00E-05, unit: m.

[0077] In Example 1, the value of 100·k1·s1 / d1+k2·s2 / d2 is selected as 4.55E-08, unit: F, which is within the upper and lower limits of 100·k1·s1 / d1+k2·s2 / d2. At this time, k1 is 3.81E-11F / m, s1 is 1.16E-02m2, k2 is 3.01E-11F / m, d1 is 1.00E-03m, d2 is 8.00E-05m, and s2 is 3.40E-03m 2 After testing, under this embodiment, after leakage occurs, the leakage detection rate is 100%, which can meet the accuracy requirements, and the safety detection results meet the requirements, which can avoid charging interruption caused by electrolyte leakage and ensure the accuracy of vehicle leakage detection.

[0078] In Example 2, the value of 100·k1·s1 / d1+k2·s2 / d2 is selected as 8.86E-10, unit: F, which is within the upper and lower limits of 100·k1·s1 / d1+k2·s2 / d2. At this time, k1 is 3.01E-11F / m, s1 is 6.72E-04m2, k2 is 2.66E-11F / m, d1 is 5.00E-03m, d2 is 8.00E-05m, and s2 is 1.45E-03m 2 After testing, under this embodiment, after leakage occurs, the leakage detection rate is 82%, which can meet the accuracy requirements, and the safety detection results meet the requirements, which can avoid charging interruptions caused by electrolyte leakage and ensure the accuracy of vehicle leakage detection.

[0079] In Example 3, the value of 100·k1·s1 / d1+k2·s2 / d2 is selected as 2.89E-08, unit: F, which is within the upper and lower limits of 100·k1·s1 / d1+k2·s2 / d2. At this time, k1 is 3.81E-11F / m, k2 is 3.01E-11F / m, d1 is 1.0E-03m, d2 is 8.00E-05m, and s1 is 7.36E-03m 2 , s2 is 2.34E-03m 2 After testing, under this embodiment, after leakage occurs, the leakage detection rate is 98%, which can meet the accuracy requirements, and the safety detection results meet the requirements, which can avoid charging interruptions caused by electrolyte leakage and ensure the accuracy of vehicle leakage detection.

[0080] In Example 4, the value of 100·k1·s1 / d1+k2·s2 / d2 is selected as 7.50E-09, unit: F, which is within the upper and lower limits of 100·k1·s1 / d1+k2·s2 / d2. At this time, k1 can be selected as 3.01E-11F / m, k2 as 2.66E-11F / m, d1 as 5.0E-03m, d2 as 8.00E-05m, and further s1 as 5.98E-03m 2 , s2 is 1.17E-02m 2 After testing, under this embodiment, after leakage occurs, the leakage detection rate is 83%, which can meet the accuracy requirements, and the safety detection results meet the requirements, which can avoid charging interruptions caused by electrolyte leakage and ensure the accuracy of vehicle leakage detection.

[0081] In Example 5, the value of 100·k1·s1 / d1+k2·s2 / d2 is selected as 1.68E-09, unit: F, which is within the upper and lower limits of 100·k1·s1 / d1+k2·s2 / d2. At this time, k1 is 3.01E-11F / m, k2 is 2.66E-11F / m, d1 is 5.00E-03m, d2 is 8.00E-05m, and s1 is 1.39E-03m 2 , s2 is 2.54E-03m 2 After testing, under this embodiment, after leakage occurs, the leakage detection rate is 81%, which can meet the accuracy requirements, and the safety detection results meet the requirements, which can avoid charging interruptions caused by electrolyte leakage and ensure the accuracy of vehicle leakage detection.

[0082] In Example 6, the value of 100·k1·s1 / d1+k2·s2 / d2 is selected as 1.74E-08, unit: F, which is within the upper and lower limits of 100·k1·s1 / d1+k2·s2 / d2. At this time, k1 is 3.81E-11F / m, k2 is 3.01E-11F / m, d1 is 1.00E-03m, d2 is 8.00E-05m, and s1 is 4.40E-03m 2 , s2 value is 1.60E-03m 2 After testing, under this embodiment, after leakage occurs, the leakage detection rate is 94%, which can meet the accuracy requirements, and the safety detection results meet the requirements, which can avoid charging interruptions caused by electrolyte leakage and ensure the accuracy of vehicle leakage detection.

[0083] In Example 7, the value of 100·k1·s1 / d1+k2·s2 / d2 is selected as 1.07E-08, unit: F, which is within the upper and lower limits of 100·k1·s1 / d1+k2·s2 / d2. At this time, the value of k1 is 3.99E-11F / m, the value of k2 is 3.01E-11F / m, the value of d1 is 3.00E-03m, the value of d2 is 8.00E-05m, and the value of s1 is 7.36E-03m 2 , s2 value is 2.34E-03m 2 After testing, under this embodiment, after leakage occurs, the leakage detection rate is 98%, which can meet the accuracy requirements, and the safety detection results meet the requirements, which can avoid charging interruptions caused by electrolyte leakage and ensure the accuracy of vehicle leakage detection.

[0084] With respect to Examples 8 to 16, by selecting the value of 100·k1·s1 / d1+k2·s2 / d2 within the upper and lower limits and by reasonably setting the values ​​of various parameters, testing has shown that leakage can be detected promptly after it occurs, meeting accuracy requirements, and the safety detection results meet requirements, thus avoiding charging interruptions caused by electrolyte leakage and ensuring the accuracy of vehicle leakage detection. This will not be further elaborated here.

[0085] In Examples 17 to 25, by selecting the value of 100·k1·s1 / d1+k2·s2 / d2 within the upper and lower limits, and focusing on making diversified selections for the value of d2, and selecting the value of d2 within the range of 5.00E-5 to 2.50E-04, and the values ​​of the other parameters are all reasonably set, after testing, it is possible to detect leakage in a timely manner after leakage occurs, meet the accuracy requirements, and the safety detection results meet the requirements, which can avoid charging interruptions caused by electrolyte leakage and ensure the accuracy of vehicle leakage detection. No further details are given here.

[0086] In Example 26, by selecting the value of 100·k1·s1 / d1+k2·s2 / d2 within the upper and lower limits, and selecting the value of d2 to 4.50E-05m, and the numerical values ​​of the remaining parameters are all reasonably set, after testing, even if the value of d2 is not in the range of 5.00E-5 to 2.50E-04, the leakage can still be detected in time after the leakage occurs, meeting the accuracy requirements, and the safety detection results meet the requirements, which can avoid charging interruptions caused by electrolyte leakage and ensure the accuracy of vehicle leakage detection.

[0087] In Comparative Example 1, the value of 100·k1·s1 / d1+k2·s2 / d2 is 5.24E-08, unit: F, which exceeds the upper limit of the value range. At this time, k1 is 3.81E-11F / m, k2 is 3.01E-11F / m, d1 is 1.0E-03m, and s1 is 1.36E-02m 2 ; s2 is 1.38E-03m 2 After testing, it was found that under this embodiment, after leakage occurred, leakage could be detected, but the safety detection result could not meet the requirements, and there was a risk of electric shock.

[0088] In Comparative Example 2, the value of 100·k1·s1 / d1+k2·s2 / d2 is 8.10E-10, unit: F, which exceeds the lower limit of the value range. At this time, k1 is 3.01E-11F / m, k2 is 2.66E-11F / m, d1 is 5.0E-03m, and s1 is 3.90E-04m 2 ; s2 is 1.73E-03m 2 After testing, it was found that, under this embodiment, although the safety detection results met the requirements, after leakage occurred, the leakage detection rate was only 65%, which could not meet the accuracy requirements and therefore could not meet the needs.

[0089] In Comparative Example 3, the value of 100·k1·s1 / d1+k2·s2 / d2 is 4.75E-08, unit: F, which exceeds the upper limit of the value range. At this time, s1 is 1.16E-02m 2 , and ensure that s1 / (s1+s2) is within the range. After testing, under this embodiment, after leakage occurs, leakage can be detected, but the safety detection result cannot meet the requirements and there is a risk of electric shock.

[0090] In some embodiments, the battery pack provided by the embodiments of the present invention satisfies: 0.22≤s1 / (s1+s2)≤0.77.

[0091] When the total area of ​​the opening surface 11 is constant, if the area s1 of the opening portion 21 increases, the area s2 of the covering portion 22 will decrease; conversely, if the area s1 of the opening portion 21 decreases, the area s2 of the covering portion 22 will increase.

[0092] Because the insulating layer 2 covering the opening surface 11 forms an opening 21, the exposed housing area increases, which in turn increases the leakage current between the adjacent conductive plates 200 and the opening surface 11. Therefore, it is necessary to rationally control the size of the opening 21, that is, the upper limit of the area s1 of the opening 21, to avoid charging interruptions caused by excessive leakage current between the adjacent conductive plates 200 and the opening surface 11, thereby ensuring the accuracy of vehicle leakage detection. Furthermore, by controlling the lower limit of the area s1 of the opening 21, the housing 1 can be opened, ensuring direct bonding between the housing and the base plate in the opening area, maintaining the bonding strength of the battery and preventing loosening.

[0093] In some embodiments, the value range of s1 is: 6.72E-04≤s1≤1.16E-02, unit: m 2 .

[0094] In some embodiments, a liquid injection hole 12 is opened on one side of the outer surface of the shell 1 , and the outer surface of the shell 1 where the liquid injection hole 12 is opened is defined as an open surface.

[0095] As a first implementation form of the positional relationship between the hole surface and the opening surface 11 , the hole surface and the opening surface 11 are two surfaces of the shell 1 arranged opposite to each other.

[0096] In this embodiment, the following conditions are met:

[0097] 1.68E-09≤100·k1·s1 / d1+k2·s2 / d2≤4.55E-08, unit: F.

[0098] As a specific example of the first implementation form, the liquid injection hole 12 is opened on the top surface of the shell 1, that is, the opening surface is the top surface of the shell 1; since the opening surface and the opening surface 11 are two opposite surfaces of the shell 1, that is, the opening surface 11 is the bottom surface of the shell 1.

[0099] The battery pack includes a bottom plate located relatively below the battery cell 100 along the Z direction;

[0100] The adjacent conductor plate 200 includes a bottom plate.

[0101] It should be noted that in this embodiment, the Z direction refers to the height direction of the battery pack, that is, the top surface and the bottom surface of the shell 1 are respectively located on both sides of the Z direction.

[0102] Combine Figure 3As shown, in this embodiment, the opening surface 11 includes the bottom surface of the housing 1, and the insulating layer 2 at least partially penetrates the area covering the opening surface 11 to form an opening portion 21. The number of opening portions 21 can be multiple, and the area s1 of the opening portion 21 in a direction perpendicular to the opening surface 11 is the sum of the areas of the multiple opening portions 21. Furthermore, the shapes of the multiple opening portions 21 can be the same or different, and no further restrictions are imposed herein.

[0103] Since the adjacent conductor plate 200 is the bottom plate of the battery pack, the opening surface 11 is the bottom surface of the shell 1 arranged opposite to the bottom plate. At this time, the bottom surface of the shell 1 is bonded to the bottom plate of the battery pack, and an opening is made in the local area of ​​the bottom surface of the shell 1 corresponding to the insulating layer 2 to increase the bonding strength of the battery cell 100.

[0104] In this embodiment, the injection hole 12 and opening 21 are located on opposing surfaces, with opening 21 relatively far from the injection hole. Detecting even minor leaks requires increasing the opening area. Therefore, the lower limit of 100·k1·s1 / d1+k2·s2 / d2 needs to be increased to ensure successful detection of electrolyte leakage. By controlling the value of 1.68E-09≤100·k1·s1 / d1+k2·s2 / d2≤4.55E-08 (unit: F), the leakage current between the bottom surface of the battery cell 100 and the bottom plate of the battery pack is controlled. This ensures accurate electrolyte leakage detection while minimizing charging interruptions and improving the accuracy of vehicle leakage detection.

[0105] In this embodiment, s1 / (s1+s2) further satisfies the following: 0.32≤s1 / (s1+s2)≤0.77. Since the injection hole 12 and the opening 21 are on opposite surfaces, leakage from the injection hole 12 can be detected promptly, and thus the opening area can be appropriately increased. It should also be noted that an excessively large opening area can result in excessive leakage current between the adjacent conductive plate 200 and the opening 11, leading to charging interruption. Therefore, if leakage from the injection hole 12 can be detected promptly, the opening area does not need to be excessively large.

[0106] In this embodiment, the distance between the opening surface and the opening surface 11 is h, and satisfies: 5.08E-04≤s1 / h*(s1+s2)≤7.56E-03, unit: m -1 .

[0107] Since the opening surface 11 and the liquid injection hole 12 are on opposite surfaces, the height of the battery will affect the opening area. If the battery height is high, in order to detect leakage as soon as possible, the opening area needs to be increased. Conversely, if the battery height is small, the opening area can be appropriately reduced.

[0108] As a second implementation form of the positional relationship between the opening surface and the opening surface 11 , the opening surface and the opening surface 11 are the same surface of the shell 1 .

[0109] In this embodiment, the following conditions are met:

[0110] 8.86E-10≤100·k1·s1 / d1+k2·s2 / d2≤1.74E-08, unit: F.

[0111] As a specific example of the second implementation form, the liquid injection hole 12 is opened on the top surface of the shell 1; since the hole opening surface and the opening surface 11 are the same surface of the shell 1, the opening surface 11 is the top surface of the shell 1.

[0112] The battery pack includes a top plate located relatively above the battery cell 100 along the Z direction;

[0113] The adjacent conductor plate 200 includes a top plate.

[0114] In this embodiment, the injection hole 12 and the opening 21 are on the same surface, allowing for prompt detection of leakage from the injection hole 12. Therefore, the opening area of ​​the opening 21 can be appropriately reduced. By controlling the value of 8.86E-10≤100·k1·s1 / d1+k2·s2 / d2≤1.74E-08, the leakage current between the top surface of the battery cell 100 and the top plate of the battery pack is controlled. This ensures accurate electrolyte leakage detection while minimizing charging interruptions and improving the accuracy of vehicle leakage detection.

[0115] In this embodiment, since the opening surface 11 and the outer surface of the shell 1 where the liquid injection hole 12 is provided are the same surface, the electrolyte is more likely to flow out from the opening 21 after leakage occurs, and leakage detection is easier.

[0116] In some embodiments, the orthographic projection of the liquid injection hole 12 on the opening surface 11 is located within the opening portion 21 .

[0117] By positioning the orthographic projection of the injection hole 12 on the opening surface 11 within the opening portion 21 , the area surrounding the injection hole 12 is prevented from being covered by the insulating layer 2 . When leakage occurs from the injection hole 12 , it can be detected in time, thereby ensuring detection efficiency.

[0118] In this embodiment, the orthographic projection area of ​​the injection hole 12, in a direction perpendicular to the opening surface 11, is defined as s3, satisfying the following conditions: 5.19E-04 ≤ s3 / s1 ≤ 1.81E-02. By controlling the upper limit of the ratio of the orthographic projection area s3 of the injection hole 12 to the area s1 of the opening portion 21, the area surrounding the injection hole 12 can be prevented from being covered by the insulating layer 2, ensuring timely detection of leakage. By controlling the lower limit of the ratio of the orthographic projection area s3 of the injection hole 12 to the area s1 of the opening portion 21, the opening area of ​​the opening portion 21 can be prevented from being too large, reducing the occurrence of charging interruptions and improving the accuracy of vehicle leakage detection.

[0119] In this embodiment, in a direction perpendicular to the opening surface 11 , the distance from the center of the orthographic projection of the liquid injection hole 12 to the center of the opening portion 21 is L, which satisfies: 0 mm ≤ L ≤ 500 mm.

[0120] Combine Figure 2 As shown, the center of the orthographic projection of the injection hole 12 in the direction perpendicular to the opening surface 11 is the axis of the injection hole 12. In the direction perpendicular to the opening surface 11, the center of the opening 21 can refer to the intersection of the center of the opening 21 along the length direction and the center along the width direction.

[0121] Preferably, the center of the orthographic projection of the injection hole 12 can coincide with the center of the opening 21, i.e., L = 0 mm. By setting an upper limit for L, the injection hole 12 can be prevented from being too close to the edge of the opening 21, preventing the area around the injection hole 12 from being covered by the insulating layer 2, thereby ensuring timely detection of leakage.

[0122] As a third implementation form of the positional relationship between the hole surface and the opening surface 11 , the hole surface and the opening surface 11 are two adjacent surfaces of the shell 1 .

[0123] In this embodiment, the following conditions are met:

[0124] 8.86E-10≤100·k1·s1 / d1+k2·s2 / d2≤2.89E-08, unit: F. As a further preferred embodiment of the third embodiment of the positional relationship between the opening surface and the opening surface 11, the housing 1 includes a top surface located at the top along the Z-direction and a bottom surface located at the bottom, and the battery cell 100 further includes a side surface located between the top and bottom surfaces; the side surface includes a first side surface and the opening surface 11, wherein the surface area of ​​the first side surface is greater than that of the opening surface 11.

[0125] At this time, it satisfies:

[0126] 9.02E-10≤100·k1·s1 / d1+k2·s2 / d2≤2.89E-08, unit: F.

[0127] In this embodiment, the first side surface refers to the large side surface of the battery, i.e., the side surface with the largest area among all the side surfaces of the battery cell 100. Since multiple battery cells 100 are stacked perpendicular to the large side surface, the adjacent conductive plate 200 corresponding to the opening surface 11 of the battery cell 100 can be a side member of the battery pack, a longitudinal beam within the battery pack, or the opening surface 11 of another battery cell 100.

[0128] Because opening 21 is located on the side of the battery and not on its larger surface, it is relatively far from injection port 12. Therefore, detecting even minor leaks requires increasing the opening area to ensure successful detection of electrolyte leakage. By controlling 0.32 ≤ s1 / (s1 + s2) ≤ 0.76, the opening area of ​​opening 21 can be effectively maintained, thereby controlling the leakage current between the opening surface 11 of the battery cell 100 and the side rails of the battery pack. This ensures accurate electrolyte leakage detection while reducing the occurrence of charging interruptions and improving the accuracy of vehicle leakage detection.

[0129] According to an embodiment of the present invention, on the other hand, there is provided an electric device including: the battery pack as described above.

[0130] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. 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, and such modifications and variations are all within the scope defined by the present invention.

Claims

1. A battery pack, characterized in that: include: A battery cell (100), the battery cell (100) comprising a shell (1) and an insulating layer (2) covering the outer surface of the shell (1); The outer surface of one side of the shell (1) is defined as an opening surface (11), and the region where the insulating layer (2) covers the opening surface (11) at least partially penetrates through the region to form an opening portion (21); the region where the insulating layer (2) covers the opening surface (11) and is located outside the opening portion (21) forms a covering portion (22); The battery pack further comprises: an adjacent conductor plate (200) adjacent to the opening surface (11), with the insulating layer (2) being spaced between the adjacent conductor plate (200) and the opening surface (11); The area of ​​the opening portion (21) is defined as s1, and the area of ​​the covering portion (22) is defined as s2; in a direction perpendicular to the opening surface (11), the minimum distance between the outer surface of the shell (1) overlapping with the projection of the opening portion (21) and close to the adjacent conductor plate (200) and the adjacent conductor plate (200) is defined as d1, and the thickness of the insulating layer (2) located at the covering portion (22) is defined as d2; satisfying: 8.86E-10≤100·k1·s1 / d1+k2·s2 / d2≤4.55E-08, unit: F; Wherein, k1 is the dielectric constant of the structural adhesive layer (3) bonded between the outer surface of the shell (1) and the adjacent conductor plate (200) at 40°C, and k2 is the dielectric constant of the insulating layer (2) at 40°C; the value range of k1 is 3.01E-11≤k1≤3.81E-11; the value range of k2 is 2.66E-11≤k2≤3.01E-11, unit: F / m; Satisfies: 0.22≤s1 / (s1+s2)≤0.77; A liquid injection hole (12) is provided on one side of the outer surface of the shell (1), and the outer surface of the shell (1) on which the liquid injection hole (12) is provided is defined as an opening surface; The hole opening surface and the opening surface (11) are the same surface of the shell (1).

2. The battery pack according to claim 1, wherein: The value range of s1 is: 6.72E-04≤s1≤1.16E-02, unit: m 2 .

3. The battery pack according to claim 1, wherein: The value range of s2 is: 1.38E-03≤s2≤1.17E-02, unit: m 2 .

4. The battery pack according to claim 1, wherein: And it satisfies: 8.86E-10≤100·k1·s1 / d1+k2·s2 / d2≤1.74E-08, unit: F.

5. The battery pack according to claim 1, wherein: The orthographic projection of the liquid injection hole (12) on the opening surface (11) is located within the opening portion (21).

6. The battery pack according to claim 5, characterized in that: In a direction perpendicular to the opening surface (11), the orthographic projection area of ​​the liquid injection hole (12) is defined as s3, which satisfies the following conditions: 5.19E-04≤s3 / s1≤1.81E-02.

7. The battery pack according to claim 5, characterized in that: In a direction perpendicular to the opening surface (11), the distance from the center of the orthographic projection of the liquid injection hole (12) to the center of the opening portion (21) is L, which satisfies the following relationship: 0mm≤L≤500mm.

8. The battery pack according to claim 1, wherein: The range of d1 is 1.00E-03≤d1≤5.00E-03, unit: m.

9. The battery pack according to claim 8, characterized in that: The range of d1 is 2.00E-03≤d1≤4.00E-03, unit: m.

10. The battery pack according to claim 1, wherein: The range of d2 is 5.00E-5≤d2≤2.50E-04, unit: m.

11. The battery pack according to claim 10, characterized in that: The range of d2 is 8.00E-5≤d2≤1.10E-04, unit: m.

12. An electrical device, characterized in that: A battery pack comprising any one of claims 1 to 11.

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