Battery pack and electric device

Abstract

The invention relates to the technical field of batteries, and discloses a battery pack and a power utilization device, the battery pack comprises a shell and an insulating layer; the outer surface of one side of the shell is defined as an opening surface, and the area, wrapping the opening surface, of the insulating layer at least partially penetrates through the opening surface to form an opening part; the adjacent conductor plates are parallel to the opening surface and are arranged at intervals; in the direction perpendicular to the opening surface, the area of the opening part is defined as s1, and the area of the coating part is defined as s2; the minimum distance between the outer surface of the shell which is overlapped with the projection of the opening part and is close to the adjacent conductor plate and the adjacent conductor plate is defined as d1, and the thickness of the insulating layer in the coating part is defined as d2; and 100 * k1 * s1 / d1 + k2 * s2 / d2 is more than or equal to 8.86 E-10 and less than or equal to 4.55 E-08, and the unit is F. According to the battery pack provided by the invention, the size of the opening part is reasonably controlled, the electrolyte leakage detection precision is ensured, meanwhile, the charging interruption condition is avoided, and the accuracy of electric leakage detection of the whole vehicle is ensured.

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 usually made of metal, such as aluminum. In order to insulate the battery shell, an insulating film is generally wrapped around the outer surface of the shell. In related technologies, the battery needs 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. For batteries with leakage, it is necessary to identify them in time to avoid defective products from entering the market.

[0003] However, when the insulating film wraps the battery, it will hinder the electrolyte leakage detection. If an opening is set in the insulating film, the battery leakage detection efficiency can be greatly improved. However, after the insulating film is set with an opening, it is easy to cause charging interruption, affecting the user's charging experience and increasing safety hazards; on the other hand, it will affect the accuracy of the 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 the leakage detection of the whole vehicle.

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

[0006] A battery cell, the 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 shell is defined as an opening surface, the area where the insulating layer covers the opening surface at least partially penetrates through the opening portion; 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 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 at the covering is defined as d2; satisfying:

[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 insulating 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 technical solution has the following beneficial effects: since the insulating layer covering the opening surface is formed with an opening, the accuracy of electrolyte leakage detection is ensured while 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 interruption, and improving the accuracy of vehicle leakage detection. When the total area of ​​the opening surface is constant, the area s2 of the covering portion is indirectly determined by reasonably setting the area s1 of the opening. And by reasonably selecting d1 and d2, the upper limit value of k1·s1 / d1+k2·s2 / d2 can be guaranteed, thereby controlling the leakage current value between the battery shell and the adjacent conductor plate 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 implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

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

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

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

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

[0021] Description of reference numerals:

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

[0023] 200. Adjacent conductor plates. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the 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 creative work are 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", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to 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 shell is usually made of metal, such as aluminum or steel. The shell is used to contain the battery cell, which includes the positive and negative electrodes and the diaphragm disposed between them, which are formed by winding or stacking. The battery cell is contained in the battery shell as the smallest independent charging and discharging unit and is electrically connected to the pole assembly disposed on the shell. In order to insulate the battery shell, an insulating layer is generally wrapped on the outer surface of the shell.

[0029] In the related art, the battery needs 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 time 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 insulating layer is wrapped outside the battery shell and the insulating layer is not opened, the electrolyte will remain between the battery shell and the insulating layer after leakage, and will not overlap with the box (or cold plate), and no circuit is formed. At this time, it is impossible to detect whether the electrolyte has leaked through the insulation detection device. When the insulating layer wrapped outside the battery shell 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 opening of the insulation layer should not be too large. The increase of the opening of the insulation layer will lead to excessive leakage current during slow charging. The RCD can detect it and cut off the high-voltage circuit, which is often said to cause the RCD to trip, resulting in charging interruption. Among them, RCD refers to the residual current protection device. The relevant standards require that the RCD detection threshold is 30mA.

[0032] Depending on the position of the opening of the insulation layer, the leakage current between the battery and the bottom 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 is too large. Excessive leakage current can easily lead to charging interruption, affecting the user's charging experience and increasing safety hazards; on the other hand, it can affect the accuracy of the vehicle leakage detection.

[0033] The battery pack provided by the embodiment 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] Combine the following Figures 1 to 4 , describing an embodiment of the present invention.

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

[0036] A battery cell 100, the battery cell 100 comprises a shell 1, and an insulating layer 2 coated on 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, and the area where the insulating layer 2 covers the opening surface 11 at least partially penetrates to form an opening portion 21; 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;

[0038] The battery pack further includes: an adjacent conductor plate 200, adjacent to the opening surface 11, and an insulating layer 2 is spaced between the adjacent conductor plate 200 and the opening surface 11;

[0039] In the 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, and the thickness of the insulating layer 2 at the covering portion 22 is defined as d2; satisfying:

[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 to the outer surface of the housing 1 and the adjacent conductor 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 implemented 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 according to the space requirements of the battery cell in the battery pack and the fixing strength requirements. 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 at least partially penetrates 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 are arranged at intervals, wherein the adjacent conductor plates 200 can be metal plates such as battery box bottom plate, side plate, liquid cooling plate, etc., and can also be metal flat plates of box beams.

[0055] The dielectric constant is a physical quantity that indicates the response of a substance to an electric field. The dielectric constant increases with the increase of the molecular dipole moment and polarizability, that is, the dielectric constant is related to the specific material of the insulating medium sandwiched between two conductors close to each other. For example, when the insulating medium sandwiched between two conductors close to each other is air, the dielectric constant is 1; for another example, when the insulating medium sandwiched between two conductors close to each other is polyvinyl chloride, the dielectric constant value ranges from 3.1 to 3.5.

[0056] In this embodiment, k1 and k2 are both related to the dielectric constant of the insulating medium sandwiched between the adjacent conductor plates 200 and the opening surface 11. Among them, k1 corresponding to the opening portion 21 area can be the product of the dielectric constant of the structural adhesive layer 3 and the dielectric constant of the vacuum, and k2 corresponding to the covering portion 22 area can be the product of the dielectric constant of the insulating layer 2 and the dielectric constant of the 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, which ensures the accuracy of electrolyte leakage detection while reasonably setting the opening size on the insulating layer, 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 controlling 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 conductor plate 200 is greater than the minimum distance d2 between the covering portion 22 and the adjacent conductor 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] In addition, by providing an opening 21 to 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 be further 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 on 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 in the insulating layer, it is convenient for the leakage detection device to use the circuit formed by the leakage for detection. The circuit is generally formed in the following manner: battery case - leaked electrolyte - battery pack case 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 the corresponding test results.

[0065] The specific safety testing method can be carried out in the following way: set up different control group experiments with 100 batteries for each group, select batteries with different window sizes to assemble into a whole pack, charge the whole pack slowly, disconnect the PE line in the slow charging gun, and measure the voltage of the body / battery pack shell to the bottom. The leakage detection rate is 80% qualified.

[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 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 are explained:

[0072] k1 is the dielectric constant of the structural adhesive layer 3 bonded to the outer surface of the shell 1 and the adjacent conductor plate 200. According to the different materials of the selected structural adhesive layer 3, through experiments, in the structural adhesive layers 3 of various materials, the upper limit of k1 is 3.81E-11, and the lower limit of k1 is 3.01E-11, unit: F / m.

[0073] k2 is the dielectric constant of the insulating layer 2. According to the different materials 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, and its value 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 interruptions 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, and its value 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 requirement, and the safety detection result meets the requirements, which can avoid charging interruption 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, and its value 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 requirement, and the safety detection result meets the requirements, which can avoid charging interruption 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, and its value 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 requirement, and the safety detection result meets the requirements, which can avoid charging interruption 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, and its value 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 requirement, and the safety detection result meets the requirements, which can avoid charging interruption 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, and its value 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 requirement, and the safety detection result meets the requirements, which can avoid charging interruption 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, and its value 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 requirement, and the safety detection result meets the requirements, which can avoid charging interruption caused by electrolyte leakage and ensure the accuracy of vehicle leakage detection.

[0084] Regarding 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, after testing, it is possible to detect leakage in time after leakage occurs, meet the accuracy requirements, and the safety detection results meet the requirements, and can avoid charging interruption caused by electrolyte leakage, ensuring the accuracy of vehicle leakage detection. I will not go into details 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 the values ​​of d2 are all selected within the range of 5.00E-5 to 2.50E-04, the values ​​of the remaining parameters are all reasonably set. After testing, the leakage can be detected in time after the leakage occurs, meeting the accuracy requirements, and the safety detection results meet the requirements, which can avoid the interruption of charging due to electrolyte leakage and ensure the accuracy of the leakage detection of the whole vehicle. I will not go into details 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 as 4.50E-05m, and the values ​​of other parameters are 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 be detected in time after the leakage occurs, meeting the accuracy requirement, and the safety detection result meets the requirements, which can avoid charging interruption 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 result met the requirements, after the leakage occurred, the leakage detection rate was only 65%, which could not meet the accuracy requirement and therefore could not meet the demand.

[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, the 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] Since the insulating layer 2 covering the opening surface 11 forms an opening 21, the exposed shell area increases, and thus the leakage current value between the adjacent conductor plate 200 and the opening surface 11 increases. Therefore, it is necessary to reasonably control the size of the opening 21, that is, the upper limit of the area s1 of the opening 21, so as to avoid the occurrence of charging interruption caused by excessive leakage current value between the adjacent conductor plate 200 and the opening surface 11, and ensure the accuracy of the vehicle leakage detection. And by controlling the lower limit of the area s1 of the opening 21, the shell 1 can have an opening, ensuring that the shell in the opening area is directly bonded to the bottom plate, ensuring the bonding strength of the battery, and avoiding 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 opening surface.

[0095] As a first implementation form of the positional relationship between the hole opening surface and the opening surface 11 , the hole opening 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 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] Combination Figure 3As shown, in this embodiment, the opening surface 11 includes the bottom surface of the housing 1, and the region 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 may be multiple, and in a 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. Furthermore, the shapes of the multiple opening portions 21 may be the same or different, and no further limitation is made here.

[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 a 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 the opening 21 are located on opposite surfaces, and the opening 21 is far away from the injection hole. In the case of a small leakage, the opening area needs to be increased to detect the leakage. Therefore, the lower limit range of 100·k1·s1 / d1+k2·s2 / d2 needs to be increased to ensure that the electrolyte leakage can be detected smoothly. By controlling 1.68E-09≤100·k1·s1 / d1+k2·s2 / d2≤4.55E-08, unit: F, the leakage current value between the bottom surface of the battery cell 100 and the bottom plate of the battery pack is controlled, while ensuring the accuracy of electrolyte leakage detection, the occurrence of charging interruption is reduced, and the accuracy of vehicle leakage detection is improved.

[0105] In this embodiment, s1 / (s1+s2) further satisfies: 0.32≤s1 / (s1+s2)≤0.77. Since the injection hole 12 and the opening 21 are on opposite surfaces, if the injection hole 12 leaks, it can be detected in time, so the opening area can be appropriately increased. At the same time, it should be noted that since a too large opening surface will lead to a too large leakage current value between the adjacent conductor plate 200 and the opening surface 11, causing charging interruption, if the injection hole 12 leaks, the opening area does not need to be too 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 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 hole opening surface and the opening surface 11 , the hole 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 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, and leakage of the injection hole 12 can be detected in time, so the opening area of ​​the opening 21 can be appropriately reduced. By controlling 8.86E-10≤100·k1·s1 / d1+k2·s2 / d2≤1.74E-08, the leakage current value between the top surface of the battery cell 100 and the top plate of the battery pack is controlled, while ensuring the accuracy of electrolyte leakage detection, the occurrence of charging interruption is reduced, and the accuracy of vehicle leakage detection is improved.

[0115] In this embodiment, since the opening surface 11 and the outer surface of the shell 1 where the 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 inside the opening portion 21 .

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

[0118] In this embodiment, in the direction perpendicular to the opening surface 11, the orthographic projection area of ​​the injection hole 12 is defined as s3, which satisfies: 5.19E-04≤s3 / s1≤1.81E-02. By controlling the upper limit of the proportion of the orthographic projection area s3 of the injection hole 12 to the area s1 of the opening 21, it is possible to avoid the surrounding area of ​​the injection hole 12 being covered by the insulating layer 2, thereby ensuring timely detection of leakage; and by controlling the lower limit of the proportion of the orthographic projection area s3 of the injection hole 12 to the area s1 of the opening 21, it is possible to avoid the opening area of ​​the opening 21 being too large, thereby reducing the occurrence of charging interruptions and improving the accuracy of vehicle leakage detection.

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

[0120] Combination Figure 2 As shown, in the direction perpendicular to the opening surface 11, the center of the orthographic projection of the injection hole 12 is the axis of the injection hole 12. In the direction perpendicular to the opening surface 11, the center of the opening 21 may 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, that is, L = 0 mm. By setting an upper limit of L, the injection hole 12 can be prevented from being too close to the edge of the opening 21, and the surrounding area of ​​the injection hole 12 can be prevented 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 opening surface and the opening surface 11 , the opening 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 solution of the third implementation form 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 also includes a side surface located between the top surface and the bottom surface; 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 is satisfied:

[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, that is, the side surface with the largest area among the sides of the battery cell 100. Since multiple battery cells 100 are stacked in a direction perpendicular to the large side surface, the adjacent conductor plate 200 corresponding to the opening surface 11 of the battery cell 100 can be a side beam of the battery pack, a longitudinal beam inside the battery pack, or an opening surface 11 of another battery cell 100.

[0128] Since the opening 21 is set on the side of the battery and not on the large surface of the battery, the opening 21 is far away from the injection hole 12. Therefore, in the case of a small leakage, the opening area needs to be increased to detect the leakage to ensure that the electrolyte leakage can be detected smoothly. By controlling 0.32≤s1 / (s1+s2)≤0.76, the opening area of ​​the opening 21 can be effectively guaranteed, and then the leakage current value between the opening surface 11 of the battery cell 100 and the side beam of the battery pack can be controlled. While ensuring the accuracy of electrolyte leakage detection, the occurrence of charging interruption is reduced, and the accuracy of vehicle leakage detection is improved.

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

[0130] Obviously, the above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. Although the embodiments of the present invention are described in conjunction with 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 all fall 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) coated on 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 (21) is defined as s1, and the area of ​​the covering (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 (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 (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, characterized in that: The value range of s1 is: 6.72E-04≤s1≤1.16E-02, unit: m 2 .

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

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

5. The battery pack according to claim 1, characterized in that: The orthographic projection of the liquid injection hole (12) on the opening surface (11) is located inside 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 injection hole (12) is defined as s3, satisfying 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 injection hole (12) to the center of the opening portion (21) is L, satisfying: 0mm≤L≤500mm.

8. The battery pack according to claim 1, characterized in that: 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, characterized in that: 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 above.

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