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] This invention relates to the field of battery technology, and more specifically to a battery pack and an electrical device. Background Technology

[0002] Battery casings are typically made of metal, such as aluminum. To insulate the casing, an insulating film is usually wrapped around its outer surface. In related technologies, electrolyte needs to be injected into the battery after assembly. Due to processing errors, sealing defects, etc., there is a certain probability of electrolyte leakage after injection. Leaking batteries need to be identified promptly to prevent defective products from entering the market.

[0003] However, when the insulating film covers the battery, it hinders the detection of electrolyte leakage. Creating openings in the insulating film could significantly improve the efficiency of battery leakage detection. However, openings in the insulating film can lead to charging interruptions, affecting the user's charging experience and increasing safety hazards; furthermore, it can affect the accuracy of overall 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 increasing the opening of the insulating film can easily lead to charging interruption and affect the accuracy of vehicle leakage detection.

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

[0006] A battery cell, which includes a housing and an insulating layer covering the outer surface of the housing;

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

[0008] The battery pack also includes: adjacent conductor plates, which are adjacent to the opening surface, and an insulating layer is spaced between the adjacent conductor plates 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 portion is defined as s2; the minimum distance between the outer surface of the shell overlapping 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 portion 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 to the outer surface of the shell and the adjacent conductor plate at 40℃, and k2 is the dielectric constant of the insulating layer at 40℃.

[0012] The range of values ​​for k1 is 3.01E-11≤k1≤3.81E-11; the range of values ​​for 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 has an opening, while ensuring the accuracy of electrolyte leakage detection, the opening size on the insulating layer can be reasonably set to control the leakage current value between the battery casing and adjacent conductors, reducing charging interruptions and improving the accuracy of vehicle leakage detection. When the total area of ​​the opening surface is constant, the area s2 of the covering part can be indirectly determined by reasonably setting the area s1 of the opening. Furthermore, by reasonably selecting d1 and d2, the upper limit of k1·s1 / d1 + k2·s2 / d2 can be guaranteed, thereby controlling the leakage current value between the battery casing and adjacent conductor plates within a safe range.

[0014] Secondly, the present invention also provides an electrical device, including 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. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a battery cell with its opening located on the side.

[0018] Figure 2 This is a schematic diagram of a battery cell with its opening located on the top surface, according to the present invention.

[0019] Figure 3 This is a schematic diagram of a battery cell with its opening located on the bottom surface, according to the present invention.

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

[0021] Explanation of reference numerals in the attached figures:

[0022] 100. Battery cell; 1. Casing; 11. Opening surface; 12. Liquid injection hole; 2. Insulating layer; 21. Opening portion; 22. Covering portion; 3. Structural adhesive layer;

[0023] 200. Adjacent conductor plates. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this 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 this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] Furthermore, 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] Battery casings are typically made of metal, such as aluminum or steel. The casing houses the battery cells, which consist of positive and negative electrodes and a separator between them. These cells are formed by winding or stacking, serving as the smallest independent charge / discharge unit housed within the battery casing and electrically connected to the terminal assembly mounted on the casing. To insulate the battery casing, an insulating layer is usually wrapped around its outer surface.

[0029] In related technologies, electrolyte needs to be injected into the battery after assembly. Due to processing errors, sealing defects, and other reasons, there is a certain probability that electrolyte leakage will occur after the battery is injected. For batteries that leak, it is necessary to identify them in time to prevent defective products from entering the market.

[0030] However, when an insulating layer surrounds the battery, it hinders electrolyte leakage detection. Adding openings to the insulating layer can significantly improve leakage detection efficiency. When the battery casing is encased in an insulating layer without openings, leaked electrolyte will remain between the casing and the insulating layer, without contacting the enclosure (or cold plate), thus creating no circuit. In this case, the leakage cannot be detected by an insulation detection device. However, when the battery casing is encased in an insulating layer with gaps, the larger the gap, the greater the probability that the leaked electrolyte will contact the enclosure (or cold plate). This creates a circuit through the battery casing, electrolyte, and enclosure / cold plate, triggering an alarm through an insulation detection device, allowing the leakage to be detected.

[0031] However, the opening in the insulation layer should not be too large. An enlarged opening can lead to excessive leakage current during slow charging, which the RCD can detect and disconnect the high-voltage circuit, commonly known as causing the RCD to trip and interrupting charging. Here, RCD refers to a residual current device, and relevant standards require an RCD detection threshold of 30mA.

[0032] Depending on the location of the opening in the insulation layer, excessive leakage current can occur between the battery and the base plate, between the battery and the metal plate of the housing beam, or between the battery and the metal plate of the liquid cooling plate. Excessive leakage current can easily lead to charging interruptions, affecting the user's charging experience and increasing safety hazards; furthermore, it can affect the accuracy of vehicle-wide leakage detection.

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

[0034] The following is combined with Figures 1 to 4 The following describes embodiments of the present invention.

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

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

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

[0038] The battery pack also includes: an adjacent conductor plate 200, which is 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 shell 1, which overlaps with the projection of the opening 21 and is close to the adjacent conductor plate 200, and the adjacent conductor plate 200 is defined as d1; the thickness of the insulating layer 2 in 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 temperature rises during operation or charging, k1 is the dielectric constant of the structural adhesive layer 3 bonded to the outer surface of the casing 1 and the adjacent conductor plate 200 at 40℃, and k2 is the dielectric constant of the insulating layer 2 at 40℃.

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

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

[0044] In this embodiment, the structural adhesive layer 3 is made of silicone structural adhesive, polyurethane or epoxy resin; the insulating layer 2 is made of PP film, PC film, PET film or PI film.

[0045] The test method for εr can be performed in accordance with the International Electrotechnical Commission standard IEC 62631-2-1:2018, and the test equipment can be an LCR tester with a test temperature of 40℃.

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

[0047] Furthermore, the preferred range for d1 is 2.00E-03≤d1≤4.00E-03, in m.

[0048] d2 is the thickness of the insulation layer in the covered part. The range of d2 is 1.00E-5≤d2≤2.50E-04, and the unit is m.

[0049] Furthermore, the preferred range for d2 is 5.00E-5 ≤ d2 ≤ 2.50E-04, in meters.

[0050] Furthermore, the preferred range for d2 is 8.00E-5≤d2≤1.10E-04, in meters.

[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 of ​​the insulating layer 2 covering the opening surface 11 at least partially extends to form an opening 21, which allows the outer surface of the housing 1 to be exposed; while the area of ​​the insulating layer 2 covering the opening surface 11 and located outside the opening 21 forms a covering portion 22, which can wrap around the area outside the opening 21, preventing the outer surface of the housing 1 in that part of the area from being exposed.

[0053] It should be noted that the area of ​​the insulating layer 2 covering the opening surface 11 is at least partially penetrated to form the opening 21. The number of openings 21 can be one or more. When there are multiple openings 21, the area s1 of the opening 21 in the direction perpendicular to the opening surface 11 is the sum of the areas of the multiple openings 21.

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

[0055] The dielectric constant is a physical quantity that measures the response of a material to an electric field. The dielectric constant increases with the increase of the molecular dipole moment and polarizability. In other words, the magnitude of the dielectric constant depends on the specific material of the insulating medium sandwiched between two closely spaced conductors. For example, when the space between two closely spaced conductors is air, the dielectric constant is 1; and when the insulating medium sandwiched between two closely spaced conductors is polyvinyl chloride (PVC), its dielectric constant 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 plate 200 and the opening surface 11. Specifically, k1 corresponding to the opening 21 region can be the product of the dielectric constant of the structural adhesive layer 3 and the vacuum dielectric constant, and k2 corresponding to the covering region 22 can be the product of the dielectric constant of the insulating layer 2 and the vacuum dielectric constant.

[0057] The battery pack provided in the embodiments of the present invention has an opening 21 formed in 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 casing and adjacent conductors, reducing the occurrence of charging interruption, and improving the accuracy of vehicle leakage detection.

[0058] In addition, by reasonably controlling the size of the opening 21, the leakage current value between the battery casing and the adjacent conductor plate 200 can be controlled, which can also improve the overall safety performance of the battery pack to a certain extent.

[0059] The minimum distance d1 between the outer surface of the shell 1, which overlaps with the projection of the opening 21, and the adjacent conductor plate 200 is greater than the minimum distance d2 between the covering part 22 and the adjacent conductor plate 200.

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

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

[0062] Additionally, providing an opening 21 in the insulating layer 2 can further increase the battery's adhesive strength. After the battery is placed in the case, it is often bonded to the base plate to ensure secure fixation, and adjacent batteries can also be bonded together. Taking the bonding of the battery to the base plate as an example, since the outer surface of the casing is covered with an insulating layer, it is essentially bonding the insulating layer to the base plate, which leads to a certain risk of detachment. By providing an opening in the insulating layer, the casing in the opening area can be directly bonded to the base plate, thereby increasing the battery's adhesive strength and ensuring a secure fixation.

[0063] It should be noted that since the electrolyte has conductive properties, after the battery leaks, the trace where the leaked liquid passes also has conductive properties. By providing an opening in the insulating layer, it is convenient for the leakage detection device to detect using the circuit formed by the leaked liquid. The general way to form the circuit is: battery case - leaked electrolyte - battery pack box or cold plate, so as to ensure that the battery with electrolyte leakage is detected; the specific detection method can be through an insulation detection method to measure the resistance value between the high voltage of the battery and the outer shell of the battery pack. Since the electrolyte is conductive, a too low resistance value indicates a leakage situation.

[0064] Additionally, when conducting leakage detection, the specific national standard for insulation detection applied can be referred to GB 18384-2020 "Safety Requirements for Electric Vehicles" for implementation and obtain the corresponding test results.

[0065] The specific safety detection method can be carried out as follows: For each group, 100 batteries are used for detection, setting different control group experiments. Assemble complete packs with batteries of different window opening sizes, perform slow charging on the complete packs, disconnect the PE wire in the slow charging gun, and measure the voltage of the vehicle body / battery pack outer shell to the bottom surface. The leakage detection rate of 80% is considered qualified.

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

[0067] The following combines several experimental examples and comparative examples to verify the specific effects of the battery pack provided by the present invention, as shown in Table 1 below.

[0068] Table 1

[0069]

[0070]

[0071] Combined with the above table, the following is explained:

[0072] k1 is the dielectric constant of the structural adhesive layer 3 bonded between the outer surface of the housing 1 and the adjacent conductor plate 200. According to the different materials of the selected structural adhesive layer 3, through experiments, among various materials of the structural adhesive layer 3, the upper limit of the value of k1 is 3.81E-11, and the lower limit of the value 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 selected insulating layer 2, through experiments, among various materials of the insulating layer 2, the upper limit of the value of k2 is 3.01E-11, and the lower limit of the value 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 of the value is 6.72E-04m. 2 The upper limit of the area s2 of the covering part 22 is 1.17E-02m. 2 The lower limit of the value is 1.38E-03m. 2 .

[0075] The minimum distance between the outer surface of the housing 1, which is close to the adjacent conductor plate 200 and whose projection overlaps with the opening 21, and the adjacent conductor plate 200, is d1. The upper limit of d1 is 5.00E-03 and the lower limit is 1.00E-03. The unit is m.

[0076] The thickness d2 of the insulating layer 2 located in the covering part 22 has an upper limit of 2.50E-04 and a lower limit of 5.00E-05, in meters.

[0077] In Example 1, the value of 100·k1·s1 / d1+k2·s2 / d2 is selected as 4.55E-08, in F. This value falls within the upper and lower limits of 100·k1·s1 / d1+k2·s2 / d2. At this point, 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 Tests showed that, under this embodiment, the leakage detection rate was 100% after leakage occurred, which met the accuracy requirements, and the safety detection results met the requirements. It 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, in F. This value falls within the upper and lower limits of 100·k1·s1 / d1+k2·s2 / d2. At this point, 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 Tests showed that, under this embodiment, the leakage detection rate was 82% after leakage occurred, which meets the accuracy requirements, and the safety detection results meet the requirements. It 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, in F. This value falls within the upper and lower limits of 100·k1·s1 / d1+k2·s2 / d2. At this point, 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 Tests showed that, under this embodiment, the leakage detection rate was 98% after leakage occurred, which meets the accuracy requirements, and the safety detection results meet the requirements. It 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, in F. This value falls within the upper and lower limits of 100·k1·s1 / d1+k2·s2 / d2. Therefore, 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 s1 as 5.98E-03m. 2 s2 is 1.17E-02m 2 Tests showed that, under this embodiment, the leakage detection rate was 83% after leakage occurred, which meets the accuracy requirements, and the safety detection results also meet the requirements. This 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, in F. This value falls within the upper and lower limits of 100·k1·s1 / d1+k2·s2 / d2. At this point, 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 Tests showed that, under this embodiment, the leakage detection rate was 81% after leakage occurred, which meets the accuracy requirements, and the safety detection results also meet the requirements. This 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, in F. This value falls within the upper and lower limits of 100·k1·s1 / d1+k2·s2 / d2. At this point, 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 The value of s2 is 1.60E-03m 2 Tests showed that, under this embodiment, the leakage detection rate was 94% after leakage occurred, which meets the accuracy requirements, and the safety detection results also meet the requirements. This 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, in F. This value falls within the upper and lower limits of 100·k1·s1 / d1+k2·s2 / d2. At this point, k1 is 3.99E-11F / m, k2 is 3.01E-11F / m, d1 is 3.00E-03m, d2 is 8.00E-05m, and s1 is 7.36E-03m. 2 The value of s2 is 2.34E-03m 2 Tests showed that, under this embodiment, the leakage detection rate was 98% after leakage occurred, which meets the accuracy requirements, and the safety detection results meet the requirements. It can avoid charging interruptions caused by electrolyte leakage and ensure the accuracy of vehicle leakage detection.

[0084] Regarding Examples 8 to 16, by selecting the values ​​of 100·k1·s1 / d1+k2·s2 / d2 within the upper and lower limits, and by reasonably setting the values ​​of each parameter, tests showed that leakage could be detected promptly after it occurred, meeting the accuracy requirements, and the safety detection results met the requirements. This avoids charging interruptions caused by electrolyte leakage and ensures the accuracy of vehicle leakage detection. Further details will not be elaborated here.

[0085] In Examples 17 to 25, by selecting the values ​​of 100·k1·s1 / d1+k2·s2 / d2 within the upper and lower limits, and focusing on diversifying the values ​​of d2, with each d2 value selected within the range of 5.00E-5 to 2.50E-04, and by setting the values ​​of all other parameters appropriately, tests showed that leakage could be detected promptly after it occurred, meeting accuracy requirements, and the safety detection results met requirements. This avoids charging interruptions caused by electrolyte leakage and ensures the accuracy of vehicle leakage detection. Further details are omitted here.

[0086] In Example 26, by selecting the values ​​of 100·k1·s1 / d1+k2·s2 / d2 within the upper and lower limits, and selecting the value of d2 as 4.50E-05m, while the values ​​of the other parameters are reasonably set, it was found that even if the value of d2 is not within the range of 5.00E-5 to 2.50E-04, leakage can still be detected in a timely manner after leakage occurs, meeting the accuracy requirements, and the safety detection results meet the requirements. This 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, in F, which exceeds the upper limit of the 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 Testing showed that in this embodiment, leakage could be detected after it occurred, but the safety detection results failed to meet the requirements, posing 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 range. At this point, 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 Testing revealed that while the safety detection results met the requirements in this embodiment, the leakage detection rate was only 65% ​​after a leak occurred, failing to meet the accuracy requirements and thus not fulfilling the overall need.

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

[0090] In some embodiments, the battery pack provided by 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 21 increases, the area s2 of the covering part 22 will decrease; conversely, if the area s1 of the opening 21 decreases, the area s2 of the covering part 22 will increase.

[0092] Because the insulating layer 2 covering the opening surface 11 forms an opening 21, the exposed shell area increases, which in turn increases the leakage current between the adjacent conductor plate 200 and the opening surface 11. 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, to avoid charging interruption caused by excessive leakage current between the adjacent conductor plate 200 and the opening surface 11, and to ensure the accuracy of leakage detection of the whole vehicle. 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 preventing loosening.

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

[0094] In some embodiments, an injection hole 12 is provided on one side of the outer surface of the housing 1, and the outer surface of the housing 1 on which the injection hole 12 is provided is defined as the opening surface.

[0095] As the first realization of the positional relationship between the opening surface and the opening surface 11, the opening surface and the opening surface 11 are two surfaces of the housing 1 that are 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, 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 surfaces opposite to each other of the shell 1, that is, the opening surface 11 is the bottom surface of the shell 1.

[0099] The battery pack includes a base plate located opposite the battery cell 100 along the Z direction;

[0100] The adjacent conductor plate 200 includes a base 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 and bottom surfaces of the casing 1 are 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. The insulating layer 2 covers the area of ​​the opening surface 11, at least partially penetrating to form an opening 21. The number of openings 21 can be multiple. In the direction perpendicular to the opening surface 11, the area s1 of the openings 21 is the sum of the areas of the multiple openings 21. Furthermore, the shapes of the multiple openings 21 can be the same or different, and no further limitations are imposed here.

[0103] Since the adjacent conductor plate 200 is the bottom plate of the battery pack, and the opening surface 11 is the bottom surface of the housing 1 which is opposite to the bottom plate, the bottom surface of the housing 1 is bonded to the bottom plate of the battery pack. The bonding strength of the battery cell 100 is increased by making an opening in a local area of ​​the insulating layer 2 corresponding to the bottom surface of the housing 1.

[0104] In this embodiment, the injection hole 12 and the opening 21 are located on opposite surfaces, with the opening 21 being farther from the injection hole. Detecting a small leak 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 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 reducing charging interruptions and improving the overall vehicle leakage detection accuracy.

[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, leakage from the injection hole 12 can be detected in a timely manner, therefore the opening area can be appropriately increased. It should also be noted that an excessively large opening area can lead to excessive leakage current between the adjacent conductor plate 200 and the opening surface 11, causing charging interruptions. Therefore, if leakage from the injection hole 12 can be detected in a timely manner, 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, in meters. -1 .

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

[0108] As a second realization 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, the injection hole 12 is opened on the top surface of the shell 1; since the opening surface and the opening surface 11 are the same surface of the shell 1, that is, the opening surface 11 is the top surface of the shell 1.

[0112] The battery pack includes a top plate located opposite 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 from the injection hole 12 can be detected in a timely manner. Therefore, 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 can be controlled. This ensures the accuracy of electrolyte leakage detection while reducing the occurrence of charging interruptions and improving the accuracy of vehicle leakage detection.

[0115] In this embodiment, since the outer surface of the opening 11 and the outer surface of the housing 1 where the injection hole 12 is opened 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 injection hole 12 onto the opening surface 11 is located within the opening 21.

[0117] By positioning the orthographic projection of the injection hole 12 onto the opening surface 11 within the opening 21, the area surrounding the injection hole 12 is prevented from being covered by the insulating layer 2. This ensures timely detection of any leakage from the injection hole 12, thereby guaranteeing detection efficiency.

[0118] In this embodiment, the projected area of ​​the injection hole 12 is defined as s3 in the direction perpendicular to the opening surface 11, satisfying: 5.19E-04≤s3 / s1≤1.81E-02. By controlling the upper limit of the proportion of the projected 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, ensuring timely detection of leakage; and by controlling the lower limit of the proportion of the projected 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, 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: 0mm≤L≤500mm.

[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 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 coincides with the center of the opening 21, i.e., L = 0 mm. By setting an upper limit for L, it is possible to prevent the injection hole 12 from being too close to the edge of the opening 21, and to prevent the area around the injection hole 12 from being covered by the insulating layer 2, thus ensuring timely detection of leakage.

[0122] As a third implementation of the positional relationship between the opening surface and the opening surface 11, the opening surface and the opening surface 11 are two surfaces of the housing 1 that are adjacent to each other.

[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 implementation 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 larger than that of the opening surface 11.

[0125] At this point, the following condition is met:

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

[0127] In this embodiment, the first side refers to the large surface of the battery, that is, the side with the largest area among all the sides of the battery cell 100. Since multiple battery cells 100 are stacked along a direction perpendicular to the large 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 the opening surface 11 of another battery cell 100.

[0128] Since the opening 21 is located on the side of the battery and not on its main surface, and is relatively far from the electrolyte injection hole 12, detecting even small leaks requires increasing the opening area to ensure successful detection. By controlling 0.32≤s1 / (s1+s2)≤0.76, the opening area of ​​the opening 21 can be effectively guaranteed, thereby controlling the leakage current between the opening surface 11 of the battery cell 100 and the side beam of the battery pack. This ensures the accuracy of electrolyte leakage detection while reducing charging interruptions and improving the accuracy of overall vehicle leakage detection.

[0129] According to an embodiment of the present invention, another aspect provides an electrical device, including a battery pack as described above.

[0130] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and all such modifications and variations fall within the scope defined by the present invention.

Claims

1. A battery pack, characterized in that, include: A battery cell (100) includes a housing (1) and an insulating layer (2) covering the outer surface of the housing (1). The outer surface of one side of the housing (1) is defined as the opening surface (11), and the area covered by the insulating layer (2) of the opening surface (11) at least partially penetrates to form an opening (21); the area covered by the insulating layer (2) of the opening surface (11) and located outside the opening (21) forms a covering part (22). A liquid injection hole (12) is provided on one side of the outer surface of the housing (1). The outer surface of the housing (1) where the liquid injection hole (12) is provided is defined as the opening surface. The opening surface and the opening surface (11) are two surfaces of the housing (1) that are opposite to each other, or the opening surface and the opening surface (11) are the same surface of the housing (1). The housing (1) is made of aluminum or steel; The insulating layer (2) is made of PET or PC; The battery pack further includes: an adjacent conductor plate (200) adjacent to the opening surface (11), and the insulating layer (2) is 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 part (22) is defined as s2; in the direction perpendicular to the opening surface (11), the minimum distance between the outer surface of the shell (1) that overlaps with the projection of the opening (21) and is 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 in the covering part (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 at 40℃ between the outer surface of the shell (1) and the adjacent conductor plate (200), and k2 is the dielectric constant of the insulating layer (2) at 40℃; 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; It satisfies: 0.22 ≤ s1 / (s1+s2) ≤ 0.77; The range of values ​​for s1 is: 6.72E-04 ≤ s1 ≤ 1.16E-02, in meters (m). 2 .

2. The battery pack according to claim 1, characterized in that, The range of values ​​for s² is: 1.38E-03 ≤ s² ≤ 1.17E-02, in meters (m). 2 .

3. The battery pack according to claim 1, characterized in that, Satisfies: 1.68E-09≤100·k1·s1 / d1+k2·s2 / d2≤4.55E-08, unit: F.

4. The battery pack according to claim 1, characterized in that, 0.32≤s1 / (s1+s2)≤0.

77.

5. The battery pack according to claim 1, characterized in that, 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, in meters. -1 .

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

7. The battery pack according to claim 1, characterized in that, And it satisfies: 8.86E-10≤100·k1·s1 / d1+k2·s2 / d2≤2.89E-08, unit: F.

8. The battery pack according to claim 1, characterized in that, The housing (1) includes a top surface located at the top along the Z direction and a bottom surface located at the bottom. 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 larger than that of the opening surface (11).

9. The battery pack according to claim 8, characterized in that, And it satisfies: 9.02E-10≤100·k1·s1 / d1+k2·s2 / d2≤2.89E-08, unit: F.

10. The battery pack according to claim 1, characterized in that, The injection hole (12) is projected onto the opening surface (11) within the opening (21).

11. The battery pack according to claim 10, characterized in that, In the direction perpendicular to the opening surface (11), the orthogonal projected area of ​​the injection hole (12) is defined as s3, which satisfies: 5.19E-04≤s3 / s1≤1.81E-02.

12. The battery pack according to claim 10, characterized in that, 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: 0mm≤L≤500mm.

13. The battery pack according to claim 1, characterized in that, The range of d1 is 1.00E-03≤d1≤5.00E-03, unit: m.

14. The battery pack according to claim 13, characterized in that, The range of d1 is 2.00E-03≤d1≤4.00E-03, unit: m.

15. The battery pack according to claim 1, characterized in that, The range of d2 is 5.00E-5≤d2≤2.50E-04, unit: m.

16. The battery pack according to claim 15, characterized in that, The range of d2 is 8.00E-5≤d2≤1.10E-04, unit: m.

17. An electrical device, characterized in that, Includes the battery pack as described in any one of claims 1 to 16 above.

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