Battery pack and electric equipment

Abstract

The invention discloses a battery pack and electric equipment, the battery pack comprises a bottom plate and a plurality of batteries arranged on the bottom plate along a first direction, each battery comprises a metal shell, the metal shell comprises two oppositely arranged first wall parts, two oppositely arranged second wall parts and a bottom surface, the area of the first wall parts is larger than that of the second wall parts, and the first wall parts and the second wall parts are arranged on the bottom surface. The first wall parts of two adjacent batteries are oppositely arranged, and the outer surfaces of the first wall parts are provided with insulating layers; the bottom surface is provided with a first exposed area; the insulation paste comprises a first part and a second part, the first part is arranged between two adjacent batteries, and the second part is arranged between the first exposed area and the bottom plate; the insulating layer and the insulating paste meet the condition that [(2D1 + D2) / 2L] H is greater than or equal to 0.001 mm and less than or equal to 2.5 mm, D1 is the thickness of the insulating layer in the first direction, D2 is the thickness of the first part in the first direction, L is the length of the battery in the first direction, and H is the distance between the top end of the first part and the top surface of the bottom plate.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically, to a battery pack and an electrical device having the battery pack. Background Technology

[0002] Battery packs can be used to store or provide electrical energy. A battery pack typically contains multiple batteries, which are connected in parallel or series to meet the pack's requirements for electrical energy or voltage.

[0003] When assembling multiple batteries into a battery pack, the batteries are housed in corresponding enclosures, and their bottom surfaces are directly bonded to the bottom plate of the enclosure. The insulating layer around the battery's metal casing weakens the bond between the battery bottom and the bottom plate, leading to potential peeling. Exposing the battery bottom casing and bonding the enclosure with an adhesive layer improves the connection strength between the battery bottom and the bottom plate, preventing separation and potential failure of the battery connection structure. However, this arrangement introduces a safety risk of short circuits between adjacent batteries. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a battery pack and an electrical device having the battery pack. The aim is to at least solve the problem of easy separation between the battery and the bottom plate of the casing.

[0005] On one hand, the present invention provides a battery pack, which includes a base plate; a plurality of batteries arranged and fixedly disposed on the base plate along a first direction, each battery including a metal casing, the metal casing including two opposing first walls and two opposing second walls, the area of ​​the first walls being larger than the area of ​​the second walls, in the plurality of batteries, the first walls of adjacent batteries being arranged opposite each other, and the outer surface of the first walls being provided with an insulating layer; the metal casing also includes a bottom surface facing the base plate, the bottom surface having a first exposed area; insulating adhesive including a first part and a second part, the first part being disposed between two adjacent batteries and fixingly connecting the two adjacent batteries, the second part being at least partially disposed between the first exposed area and the base plate and fixingly connecting the batteries and the base plate; the insulating layer and the insulating adhesive satisfy: 0.001mm≤[(2D1+D2) / 2L]×H≤2.5mm.

[0006] Wherein, D1 is the thickness of the insulating layer in the first direction, in mm; D2 is the thickness of the first part in the first direction, in mm; L is the length of the battery in the first direction, in mm; and H is the distance between the top of the first part and the top surface of the base plate, in mm.

[0007] On the other hand, the present invention provides an electrical device that includes a battery pack as described above.

[0008] According to the battery device and electrical equipment provided in this disclosure, by setting an exposed area on the bottom surface of the metal casing, the metal casing and the bottom plate of the housing are directly bonded together with insulating adhesive to improve the connection strength between the battery and the bottom plate. The batteries are arranged along the first direction, improving the overall internal space utilization of the battery. Furthermore, the thickness of the insulating layer and the insulating adhesive in the first direction, as well as the distance between the insulating adhesive and the bottom plate, are reasonably set to satisfy the formula 0.001mm≤[(2D1+D2) / 2L]×H≤2.5mm. Within this range, on the one hand, the electrical safety between adjacent batteries can be improved, avoiding safety risks such as short circuits between adjacent batteries; on the other hand, it can also prevent adjacent batteries from expanding along the first direction, where insufficient expansion space leads to excessive internal pressure in the battery, causing the risk of thermal runaway and battery explosion. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a top view of an exemplary battery pack of the present invention.

[0011] Figure 2 for Figure 1 A partial schematic diagram of the sectional view along the BB direction.

[0012] Figure 3 for Figure 2 A schematic diagram of the structure between any two adjacent batteries, as exemplified in the example.

[0013] Figure 4 for Figure 2 A schematic diagram of the structure in which the barrier between any two adjacent batteries is fixedly connected to the insulating adhesive.

[0014] Figure 5 for Figure 2 A schematic diagram showing a structure in which there is a gap between the barrier and the insulating adhesive between any two adjacent batteries.

[0015] Figure 6 This is a schematic diagram of an exemplary battery.

[0016] Figure 7 This is a front view of an exemplary battery.

[0017] In the picture, 100. Battery pack; 10. Base plate; 20. Battery; 21. Insulating layer; 22. Cell; 23. Metal casing; 231. First wall portion; 232. Second wall portion; 233. Bottom surface; 24. Terminal post; 30. Insulating adhesive; 31. First part; 32. Second part; 40. Barrier component; 50. First spacer; 60. Second spacer. Detailed Implementation

[0018] In one related technology, to address the issue of insulation between multiple batteries within a battery pack, an insulating film or insulating coating is applied to the sidewalls, or bottom surface, of the battery casing. When assembling multiple batteries onto a base plate, the corresponding insulating film or coating on the bottom surface of the casing is bonded to the base plate using structural adhesive. In other words, the bonding relationship between the battery and the base plate becomes the bonding between the insulating film or coating and the base plate. During operation, the connection between the bottom surface of the casing and the insulating film or coating often fails, directly leading to the separation of the battery from the base plate.

[0019] To address the aforementioned problems, the inventors made numerous attempts. First, they discovered that an insulating film or coating could be omitted from the bottom surface of the casing, allowing direct bonding between the bottom surface of the battery casing and the base plate. However, this approach increased the risk of insulation failure between adjacent batteries. The inventors then discovered that using insulating adhesive as a structural adhesive, and ensuring that the adhesive met certain dimensional requirements, could solve the problem of insulation failure between adjacent batteries. Ultimately, the inventors creatively proposed the following technical solution: By creating an exposed area on the bottom surface of the metal casing, the metal casing and the bottom plate of the housing are directly bonded together with insulating adhesive, improving the connection strength between the battery and the bottom plate. The batteries are arranged along the first direction, increasing the overall internal space utilization of the battery. Furthermore, the thickness of the insulating layer and the insulating adhesive in the first direction, as well as the distance between the insulating adhesive and the bottom plate, are rationally set to satisfy the formula 0.001mm ≤ [(2D1+D2) / 2L]×H ≤ 2.5mm. Within this range, on the one hand, electrical safety between adjacent batteries can be improved, avoiding safety risks such as short circuits between adjacent batteries; on the other hand, it can also prevent adjacent batteries from expanding along the first direction, where insufficient expansion space could lead to excessive internal pressure and the risk of thermal runaway causing battery explosion.

[0020] Research has found that when the first walls of two adjacent batteries are positioned opposite each other, and this first wall constitutes the large surface area of ​​the battery casing, the internal expansion of the battery is significant. The insulating adhesive placed between adjacent batteries reduces the expansion space of the internal cells during charging and discharging, causing internal pressure to accumulate and potentially leading to the abnormal opening of the battery's explosion-proof valve, thus affecting the overall safety of the battery pack. However, the absence of insulating adhesive between adjacent batteries results in a smaller electrical safety distance, creating a safety risk of overlap between adjacent batteries.

[0021] The formula [(2D1+D2) / 2L]×H has a narrow range, resulting in a short electrical insulation distance between adjacent batteries and an increased risk of short circuits. Besides the first exposed area on the bottom of the metal casing, the sides of the metal casing are also prone to short circuits due to insufficient electrical safety distances. Conversely, if the formula range is too large, the excessive thickness and / or height of the insulating adhesive and insulation layer between batteries can lead to higher internal pressure, posing a safety risk of abnormal battery pressure leakage.

[0022] 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, and 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.

[0023] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0024] Furthermore, the terminology used in the description of this invention is for illustrative purposes only and is not intended to limit the scope of the invention. The terms "comprising" and / or "including" are used to specify the presence of said elements, steps, operations, and / or components, but do not exclude the presence or addition of one or more other elements, steps, operations, and / or components. The terms "first," "second," etc., may be used to describe various elements, do not represent an order, and do not limit these elements. Moreover, in the description of this invention, unless otherwise stated, "a plurality of" means two or more. These terms are used only to distinguish one element from another. These and / or other aspects become apparent in conjunction with the following drawings, and those skilled in the art will more readily understand the description of the embodiments of the invention. The drawings are used for illustrative purposes only to depict the embodiments of the invention. Those skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods shown in the invention can be employed without departing from the principles of the invention.

[0025] For ease of understanding, in the attached figures, the X-axis represents the width direction of the battery pack, which is also the width direction of the battery, or the first direction; the Y-axis represents the length direction of the battery pack, which is also the length direction of the battery; and the Z-axis represents the height direction of the battery pack, which is also the height direction of the battery. The positive direction of the Z-axis indicates the direction from the bottom surface of the battery pack to its top surface, which is also the direction from the bottom surface of the battery to its top surface. The terms "top" or "bottom" used in any element of this disclosure can be used as a reference here.

[0026] <Example Battery Pack> This invention provides a battery pack 100. The overall structure of the battery pack 100 according to this disclosure will be described below by way of example. It should be understood that the structure of the battery pack 100 is not limited to the following description. For example, one or more elements mentioned below may be omitted or replaced, and their layout relationships may be changed.

[0027] See Figures 1 to 6 The battery pack 100 includes a base plate 10, multiple batteries 20, insulating adhesive 30, and barrier components 40.

[0028] Battery 20 is an energy storage unit capable of repeated charging and discharging, and can be interpreted as a "secondary battery". In this application, the concept of "secondary battery" can be, but is not limited to, lithium-ion secondary batteries, sodium-ion secondary batteries, lead-acid batteries, and nickel-metal hydride batteries, etc.

[0029] The battery 20 can be, for example, a square battery, which can be understood as a battery in the shape of a quadrangular prism. The battery 20 can also be other types of batteries that, when arranged along the first direction, have two opposing first walls 231. The battery pack 100 of the present invention will be described in detail below using a square battery as an example.

[0030] by Figure 1 For example, multiple batteries 20 in the battery pack 100 are arranged along a first direction on the base plate 10. Figure 1 The area enclosed by the dashed line can be understood as the smallest unit of arrangement of multiple batteries 20, and can be called a battery pack or battery module. The battery pack 100 may include one battery module or multiple battery modules. The number of batteries 20 in each battery module can be determined according to the capacity or voltage requirements of the battery pack 100. This application does not specifically limit the number of batteries 20 contained in a battery module. The following will use a single battery module as an example to specifically describe the battery pack 100 described in this application.

[0031] The first direction can be understood, for example, as the width direction of the battery pack 100, that is, multiple batteries 20 are arranged sequentially along the width direction of the battery pack 100 to form a battery module. One or more battery modules are assembled into the corresponding housing to form the battery pack 100.

[0032] It should be noted that multiple batteries 20 can also be arranged along the length direction, height direction or other specific direction of the battery pack 100, and the first direction does not have a special meaning.

[0033] The base plate 10 can be understood, for example, as part of the housing of the battery pack 100, that is, the bottom part of the housing. The base plate 10 can also be understood as an independent part, that is, it can be connected to the housing through a specific connection structure.

[0034] The base plate 10 serves to mount and support the battery; it can be a simple support plate or a functional heat exchange plate. When used as a heat exchange plate, it has heat exchange channels in the middle, allowing heat exchange between the battery and the heat exchange medium. Depending on the battery pack's operating environment and requirements, the heat exchange plate can function as both a cooling and heating plate. The base plate 10 can be connected to the battery frame around its perimeter using fasteners such as bolts, drill screws, or structural adhesive.

[0035] The base plate 10 is a metal plate, which can be made of aluminum, steel, copper, nickel, titanium, or other metals or their alloys. See also Figure 6 Each battery 20 in the battery module includes a cell 22 and a metal casing 23. The metal casing 23 mainly provides protection and support for the battery 20, and the cell 22 is housed within the space formed by the metal casing 23. The metal casing 23 includes, for example, two opposing first wall portions 231, two opposing second wall portions 232, and a bottom surface 233. The area of ​​the first wall portion 231 is larger than the area of ​​the second wall portion 232.

[0036] Specifically, the two first wall portions 231 can be, for example, two wall portions arranged opposite each other in the width direction of the battery 20; the two second wall portions 232 can be, for example, two wall portions arranged opposite each other in the length direction of the battery 20; and the bottom surface 233 can be, for example, a surface located at the bottom end in the height direction of the battery 20. The two first wall portions 231, the two second wall portions 232, and the bottom surface 233 together form the receiving space of the metal casing 23.

[0037] In this embodiment, multiple batteries 20 are arranged along the width direction of the battery pack 100, so that in the battery module composed of multiple batteries 20, the first wall portions 231 of any two adjacent batteries 20 are arranged opposite each other, that is, the larger wall portions of the metal casing 23 are arranged opposite each other.

[0038] The first wall portion 231 is provided with an insulating layer 21. It can be understood that the insulating layer 21 is provided on the surface of the first wall portion 231 away from the battery cell 22. This surface of the first wall portion 231 away from the battery cell 22 can be referred to as the outer surface of the first wall portion 231. Providing an insulating layer on the outer surface of the first wall portion 231 can improve the insulation performance between two adjacent batteries 20, preventing insulation failure between any two adjacent batteries 20 in the battery module due to contact between the opposing first walls 231.

[0039] Optionally, the insulating layer 21 can be an insulating film or an insulating coating, or other layer structure with insulating function. The insulating film can be made of materials such as polyethylene terephthalate, polyimide, polypropylene, or acrylic adhesive. The insulating coating can be made of materials such as polyethylene terephthalate, polyimide, mica, UV coating materials, or epoxy resin. See also Figures 3 to 5 The battery pack 100 also includes insulating adhesive 30. The insulating adhesive 30 includes a first part 31 and a second part 32. The first part 31 is disposed between two adjacent batteries 20 and fixably connects the two adjacent batteries 20, and the second part 32 is disposed between the first exposed area of ​​the bottom surface 233 of the metal casing 23 and the base plate 10 and fixably connects the battery 20 and the base plate 10.

[0040] Specifically, the first portion 31 is disposed in the region between the two opposing first wall portions 231 of two adjacent batteries 20. That is, the first portion 31 is "clamped" between the first wall portion 231 on the right side of the first battery 20 and the first wall portion 231 on the left side of the second battery 20. It can be understood that the first portion 31 is in contact with the insulating layer 21 disposed on the outer surface of the first wall portion 231. Thus, the portion of the first wall portion 231 near the bottom surface 233 not only has the insulating layer 21 but also has the first portion 31. At this location, the insulating layer 21 and the first portion 31 can simultaneously provide insulation for the battery 20. In this way, the first portion 31 can not only improve the electrical safety of the two adjacent batteries 20, but also provide a certain degree of adhesive fixation for the two adjacent batteries 20, thereby improving the stability of the battery 20 within the metal casing 23.

[0041] Based on this, the second part 32 is disposed between the bottom surface 233 of the two adjacent batteries and the base plate 10. That is, the second part 32 extends along the width direction of the battery pack 100 on the top surface of the base plate 10.

[0042] Specifically, a first exposed area is provided on the bottom surface 233, and a second part 32 is located between the first exposed area and the base plate 10. In this way, the battery 20 can be directly bonded to the base plate 10 through the second part 32 of the first exposed area, which improves the stability of the bond between the battery 20 and the base plate 10 and reduces the risk of peeling between them.

[0043] It should be noted that the first part 31 and the second part 32 can be formed in one step or in stages. For example, the second part 32 can be formed on the base plate 10 first, and then the first part 31 can be formed between two adjacent batteries 20. Furthermore, there is no clear dividing line between the first part 31 and the second part 32; they are artificially distinguished. The first part 31 and the second part 32 do not have any particularly limiting meaning.

[0044] Optionally, the insulating adhesive 30 can be, for example, polyurethane structural adhesive, acrylic structural adhesive, or epoxy structural adhesive. Part 31 and Part 32 can be selected from the same material or from different materials. This application does not specifically limit them.

[0045] Preferably, the elastic modulus of the first part 31 is less than that of the second part 32. In this way, the first part 31 can provide expansion space for the buffer between two adjacent batteries 20, ensuring the orderly flow of gas inside the battery 20 and preventing the battery 20 from bursting prematurely due to excessive gas pressure inside the battery 20.

[0046] The inventors discovered that a stable connection between the battery 20 and the base plate 10 can be achieved while simultaneously ensuring insulation between adjacent batteries 20 within the battery module. This can be achieved by setting the corresponding dimensions of the insulating layer 21 and the insulating adhesive 30 such that the dimensions satisfy the following relationship: this ensures insulation not only between the battery 20 and the base plate 10, but also between adjacent batteries 20.

[0047] 0.001mm≤[(2D1+D2) / 2L]×H≤2.5mm (1) Where D1 is the thickness of the insulating layer 21 in the first direction, in mm. That is, D1 is the thickness of the insulating film or insulating coating on the outer surface of the first wall portion 231 in the first direction. Specifically, it is the vertical distance from the side of the insulating layer 21 closest to the first wall portion 231 to the side furthest from the first wall portion 231 at a certain location. It can be understood that the thickness of the insulating layer 21 should be considered a uniform thickness, meaning the thickness of the insulating layer 21 is equal at all locations. However, if the thickness of the insulating layer 21 differs at some locations from other locations, the average value of the overall thickness of the insulating layer 21 can be used as the value of D1. The larger the value of D1, the better the insulation effect of the insulating layer 21; conversely, the smaller the value of D1, the worse the insulation effect of the insulating layer 21.

[0048] D2 is the thickness of the first part 31 in the first direction, in mm. For example, D2 can be understood as the vertical distance from the outer surface of the insulating layer 21 on the right side of the first battery 20 to the outer surface of the insulating layer 21 on the left side of the second battery, in two adjacent batteries 20. It can be understood that the thickness of the first part 31 is uniform, meaning the thickness is equal at all locations. For cases where the thickness of the first part 31 is non-uniform, the average thickness of the entire first part 31 can be used as the value of D2. The larger the value of D2, the better the insulation effect between two adjacent batteries 20; conversely, the smaller the value of D2, the worse the insulation effect between two adjacent batteries 20.

[0049] L represents the length of the battery 20 in the first direction, measured in mm. For example, L can be understood as the distance between two relatively disposed first wall portions 231 of the battery 20, i.e., the distance between the outer surface of one first wall portion 231 and the outer surface of the other. It can be understood that L should be interpreted as the distance between the two first wall portions 231 when the metal casing 23 has not undergone any deformation. The value of L varies depending on the battery 20; this application primarily focuses on the proportional relationship between L and several other elements.

[0050] H is the distance between the top of the first part 31 and the top surface of the base plate 10, in mm. For example, H can be understood as the vertical distance from the end of the first part 31 furthest from the base plate 10 to the top surface of the base plate 10 at its corresponding position. It can be understood that the distance between all positions of the top of the first part 31 and the top surface of the base plate 10 is equal. If the distances between the various positions of the top of the first part 31 and the top surface of the base plate 10 are unequal, the average value of the distances between all positions of the first part 31 and the top surface of the base plate 10 can be used as the value of H. The larger the value of H, the better the insulation effect between two adjacent batteries 20; conversely, the smaller the value of H, the worse the insulation effect between two adjacent batteries 20.

[0051] For ease of description, the above inequality will be referred to as Equation 1 below. A battery pack 100 that satisfies the above range can not only ensure a firm bond between the battery 20 and the base plate 10, but also ensure insulation between two adjacent batteries 20.

[0052] It can be understood that, based on Equation 1 satisfying the above range, the thickness D1 of the insulating layer 21 in the first direction satisfies a certain range of values, for example, D1 satisfies: 0.05mm≤D1≤0.2mm.

[0053] Optionally, D1 can be 0.06mm, 0.08mm, 0.1mm, 0.12mm, 0.15mm, 0.16mm, 0.18mm, and 0.19mm. A D1 within the above range not only ensures that the insulating layer 21 has sufficient thickness to provide good insulation for the battery 20, but also prevents it from being scratched during use, further improving the insulation performance of the battery 20. At the same time, it avoids making the insulating layer 21 too thick, meaning it won't substantially affect the energy density of the battery 20, keeping the energy density of the battery 20 within a relatively ideal range.

[0054] Similarly, based on Equation 1 satisfying the above range, the first part 31 of the insulating adhesive 30 satisfies a certain value range. For example, the first part 31 satisfies: 0.2mm≤D2≤0.7mm, and / or, 0.5mm≤H≤20mm.

[0055] Optionally, D2 can be 0.3mm, 0.4mm, 0.5mm, or 0.6mm, etc. H can be 2mm, 5mm, 6mm, 8mm, 10mm, 12mm, 15mm, 16mm, 17mm, 18mm, or 19mm, etc.

[0056] A D2 that meets the above range can, on the one hand, ensure a sufficient safe distance between two adjacent batteries 20, thus preventing the risk of short circuit between the two batteries 20; on the other hand, it will not make the gap between two adjacent batteries 20 too large, thus affecting the energy density of the battery pack 100.

[0057] If H satisfies the above range, on the one hand, the first part 31 can extend a sufficient distance in the height direction of the battery 20, thereby reducing the risk of insulation failure caused by the direct bonding of the bottom surface 233 of the metal casing 23 to the base plate 10; on the other hand, the height of the first part 31 will not be too large, that is, sufficient expansion space can be left for the two adjacent batteries 20, reducing the risk of thermal runaway of the battery 20 due to excessive internal pressure.

[0058] In addition, battery 20 meets the requirement of 25mm ≤ L ≤ 150mm. For example, L can be 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 120mm, 130mm, or 140mm, etc. In use, L can be determined according to the requirements of battery 20, and then D1, D2, and H can be determined according to the value of L.

[0059] It is understandable that only a portion of the bottom surface 233 can be designated as the first exposed area, or all of the bottom surface 233 can be designated as the first exposed area. When the entire bottom surface 233 is designated as the first exposed area, the risk of short circuit between adjacent batteries 20 increases, requiring appropriate adjustment of the range of Equation 1 to improve the insulation effect between adjacent batteries 20. For example, the insulating layer 21 and the insulating adhesive 30 satisfy the following relationship: 0.04mm≤[(2D1+D2) / 2L]×H≤2.5mm (2) Meeting the above requirements not only ensures a firm bond between the battery 20 and the base plate 10, but also ensures insulation between two adjacent batteries 20.

[0060] In one alternative embodiment, the insulating layer 21 completely covers the first wall portion 231. That is, the orthographic projection of the insulating layer 21 onto the first wall portion 231 completely coincides with the first wall portion 231. For example, it can be understood that the length of the insulating layer 21 in the longitudinal direction of the battery 20 is equal to the length of the first wall portion 231 in the longitudinal direction of the battery 20; and the height of the insulating layer 21 in the height direction of the battery 20 is equal to the height of the first wall portion 231 in the height direction of the battery 20.

[0061] Specifically, taking a square battery as an example, the upper edge of the insulating layer 21 is flush with the upper edge of the first wall portion 231; the lower edge of the insulating layer 21 is flush with the lower edge of the first wall portion 231; the left edge of the insulating layer 21 is flush with the left edge of the first wall portion 231; and the right edge of the insulating layer 21 is flush with the right edge of the first wall portion 231.

[0062] At this point, the insulation effect between the two adjacent batteries 20 is good, and the risk of failure is reduced. Therefore, the range of Equation 1 can be appropriately adjusted. The relevant dimensions of the insulating layer 21 and the insulating adhesive 30 can satisfy the following relationship: 0.001mm≤[(2D1+D2) / 2L]×H≤2.5mm (3) Meeting the aforementioned requirements not only ensures the insulation effect between the battery 20 and the base plate 10, but also ensures that the size of the insulating adhesive between two adjacent batteries 20 is small. This allows for more space between two adjacent batteries 20, preventing the explosion-proof valve of the battery 20 from abnormally opening due to insufficient expansion space after expansion.

[0063] In one alternative embodiment, the insulating layer 21 extends onto the bottom surface 233. That is, in addition to completely covering the first wall portion 231, a portion of the insulating layer 21 extends onto the bottom surface 233. In this way, a portion of the bottom surface 233 is also covered by the insulating layer 21, increasing the creepage distance between two adjacent batteries 20 and reducing the risk of short circuit between two adjacent batteries 20.

[0064] Preferably, the ratio of the dimensions C and L of the insulating layer 21 extending on the bottom surface 233 is 0.02 ≤ C / L ≤ 0.3. Satisfying the above range ensures that the extended dimension of the insulating layer 21 is large enough to reduce the risk of short circuit between two adjacent batteries 20; on the other hand, it ensures that the extended dimension of the insulating layer 21 is not too large, so as not to affect the bonding strength between the battery 20 and the base plate 10.

[0065] The value of C ranges from 1mm to 10mm. For example, C can be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, or 9mm, etc.

[0066] In one alternative embodiment, the insulating layer 21 partially covers the first wall portion 231, thereby giving the first wall portion 231 a second exposed area, and the first portion 31 at least partially covers the second exposed area.

[0067] It is understandable that when the insulating layer 21 does not completely cover the first wall portion 231, that is, when there is a second exposed area on the first wall portion 231, the portion of the metal casing 23 corresponding to the second exposed area is exposed. By partially or completely covering the second exposed area with the first portion 31, the metal casing 23 within the second exposed area can provide insulation, reducing the risk of short circuits between two adjacent batteries 20. In addition, the first portion located in the second exposed area can also provide adhesion between the two adjacent batteries 20, thereby improving the overall strength between the two adjacent batteries 20.

[0068] At this point, the height H of the first part 31 can be adjusted appropriately. For example, the value of H can be in the range of 5mm-20mm. Within this range, H can ensure that the first part 31 has sufficient height to reduce the risk of short circuit between two adjacent batteries 20; on the other hand, it will not make H too large, thus leaving more space between two adjacent batteries 20, avoiding insufficient expansion space for the batteries 20, and reducing the risk of thermal runaway between two adjacent batteries 20.

[0069] It is easy to understand that when the first wall portions 231 of two adjacent batteries 20 are both provided with second exposed areas, the risk of short circuit between the two adjacent batteries 20 increases. In this case, the risk of short circuit between the two batteries 20 can be reduced by appropriately adjusting the range of Equation 1. For example, the range of Equation 1 can be adjusted as follows: 0.05mm≤[(2D1+D2) / 2L]×H≤2.5mm (4) By satisfying the range of Equation 4, the thickness of the insulating layer 21 and / or the first portion 31 in the first direction can be larger, and / or the height H of the first portion 31 can be larger. This increases the creepage distance between two adjacent batteries 20, reducing the short-circuit risk between them.

[0070] In one alternative implementation, such as Figure 7 As shown, in a direction perpendicular to the base plate 10, the edge of the insulating layer 21 located on the first wall portion 231, parallel to and near the bottom surface 233, has a first gap 50 between it and the bottom surface 233. That is, the insulating layer 21 does not completely cover the first wall portion 231.

[0071] Specifically, taking a square battery as an example: the lower edge of the insulating layer 21 is not flush with the lower edge of the first wall portion 231, thus creating a first gap 50 between them. It is understood that the first wall portion 231 located within the first gap 50 area is exposed, meaning that this portion of the first wall portion 231 is at risk of insulation failure. Therefore, the range of Equation 1 can be appropriately adjusted so that the insulating layer 21 and insulating adhesive 30, satisfying the following relationship, can still ensure the insulation effect of the battery pack 100. At this time, the insulating layer 21 and insulating adhesive 30 satisfy: 0.01mm≤[(2D1+D2) / 2L]H≤2.5mm (5) For ease of description, the above relationship is referred to as Equation 5. When Equation 5 satisfies the above range, it can ensure a stable bond between the battery 20 and the base plate 10, and at the same time, it can also ensure the insulation effect between two adjacent batteries 20.

[0072] Furthermore, in the direction perpendicular to the base plate 10, H is greater than the height of the first interval 50. That is, the extension distance of the first portion 31 in the height direction of the battery 20 is greater than the distance of the first interval 50 in the height direction of the battery 20. Thus, the first portion 31 provides insulation to the first wall portion 231 located within the area of ​​the first interval 50. This reduces the risk of insulation failure between two adjacent batteries 20 due to the first interval 50.

[0073] Preferably, the height of the first gap 50 in the direction perpendicular to the base plate 10 ranges from 0.1mm to 0.3mm. A first gap 50 that meets the above range can ensure that the first wall portion 231 has a sufficiently large insulating layer 21 to reduce the risk of short circuit between two adjacent batteries 20.

[0074] In one optional embodiment, the dielectric constant of the insulating adhesive 30 ranges from 2 F / m to 5.5 F / m. For example, the dielectric constant of the insulating adhesive 30 can be 2.5 F / m, 3.0 F / m, 3.5 F / m, 4.0 F / m, or 4.5 F / m. Insulating adhesive 30 meeting the above range ensures its insulation effect and improves the safety performance between adjacent batteries 20.

[0075] See Figure 4 In one optional embodiment, the battery pack 100 further includes a barrier 40 located between the first wall portions 231 of any two adjacent batteries 20. The barrier 40 can be, for example, a separator or a barrier frame, a structural component with a certain structural strength. It can provide a certain degree of isolation between two adjacent batteries 20, increasing the creepage distance between adjacent batteries 20 and further reducing the risk of insulation failure between adjacent batteries 20.

[0076] Alternatively, the barrier 40 can be, for example, a heat exchange plate or a heat insulation pad with heat exchange function to prevent heat conduction between adjacent batteries 20. In this case, the barrier 40 can be aerogel, silicone frame, etc. with heat insulation effect; or it can be a metal heat exchange plate with a heat exchange channel in the heat exchange plate containing a liquid, gas or a cooling medium capable of phase change.

[0077] Understandably, the thickness of the barrier 40 should be less than the thickness of the first portion 31. That is, the barrier 40 does not contact the first wall portion 231 of either of the two adjacent batteries 20. This allows for sufficient expansion space to be provided for the two adjacent batteries 20, reducing the risk of thermal failure due to excessive internal pressure.

[0078] Furthermore, a portion of the barrier member 40 is fixedly connected to the insulating adhesive 30. It can be understood that the portion of the barrier member 40 closest to the insulating adhesive 30 is fixedly connected to the insulating adhesive 30. That is, the bottom of the barrier member 40 is bonded to the first part 31; for example, the bottom of the barrier member 40 is inserted into the first part 31. In this way, the first part 31 can fix the barrier member 40, eliminating the need for additional fixing structures for the barrier member 40, which helps reduce the weight of the battery 20. Simultaneously, the fixed connection between the barrier member 40 and the first part 31 ensures that there are no points where short circuits could occur between the first walls 231 of adjacent batteries 20, further improving the insulation effect between adjacent batteries 20.

[0079] Alternatively, see Figure 5 There is a second gap 60 between the barrier 40 and the insulating adhesive 30. That is, the bottom of the barrier 40 does not contact the first part 31, and there is a second gap 60 between them in the height direction of the battery 20. In this way, the second gap 60 can also reserve a certain space for the expansion of the battery 20, reducing the risk of thermal runaway of the battery 20.

[0080] It is understood that, at this time, the barrier 40 can be fixed through its upper part. For example, the barrier 40 can be fixed to the top surface of the metal housing 23 through its upper part. The barrier 40 can also be fixed in other ways, which are not specifically limited in this application.

[0081] In one alternative embodiment, the height of the cell 22 is M in the direction perpendicular to the base plate 10, and the ratio of H to M ranges from 0.002 to 0.15.

[0082] The height of cell 22 here can be understood as excluding the height of cell 22 with terminal posts. The first part 31 meets the above range, which can make the first part 31 have sufficient height to reduce the risk of short circuit between adjacent batteries 20; at the same time, it will not make the height of the first part 31 too large, avoiding the risk of cell 22 falling off, and the battery 20 explosion-proof valve abnormally opening due to the small expansion space of the battery 20.

[0083] In an optional embodiment, the battery 20 further includes an explosion-proof valve disposed on the bottom surface 233 of the metal housing 23. It is understood that the explosion-proof valve is generally thinned or defect-treated to facilitate the release of pressure within the metal housing 23. In this case, the insulating adhesive 30 at the location corresponding to the explosion-proof valve is designed with a perforated structure to expose the valve. That is, no insulating adhesive is provided at the location corresponding to the explosion-proof valve. Consequently, the bonding area of ​​the insulating adhesive 30 between the battery 20 and the base plate 10 is reduced, allowing for further limitation of Equation 1. This ensures that the insulating layer 21 and the insulating adhesive 30 satisfying the following relationship not only achieve stable bonding between the battery 20 and the base plate 10 but also ensure the insulation effect of the battery pack 100. At this time, the insulating layer 21 and the insulating adhesive 30 satisfy: 0.15mm≤[(2D1+D2) / 2L]H≤2.5mm (6).

[0084] For ease of description, the above relationship is referred to as Equation 6. When Equation 6 satisfies the above range, it can ensure a stable bond between the battery 20 and the base plate 10, and at the same time, it can also ensure the insulation effect between two adjacent batteries 20.

[0085] In one alternative embodiment, the battery cell 22 includes a base plate located between the bottom surface of the battery cell 22 and the metal casing 23.

[0086] Optionally, the end of the first portion 31 furthest from the base plate 10 is located above the base plate. That is, the top of the first portion 31 is positioned higher than the top of the base plate in the height direction of the battery 20. Furthermore, the extension distance of the first portion 31 in the height direction of the battery 20 should be less than 2 / 5 of the height of the battery 20.

[0087] At this time, the space for expansion of cell 22 during charging and discharging is reduced. To ensure the thermal stability of battery 20, the range of Equation 1 needs to be appropriately adjusted. That is, the insulating layer 21 and the insulating adhesive 30 satisfy the following relationship: 0.001mm≤[(2D1+D2) / 2L]×H≤2.0mm (7) For ease of description, the above relationship is referred to as Equation 7. When Equation 7 satisfies the above range, it can not only ensure the insulation effect between two adjacent batteries 20, but also ensure that there is enough expansion space for two adjacent batteries 20, so as to avoid the problem of abnormal explosion-proof valve opening due to small expansion space.

[0088] Alternatively, the end of the first part 31 closest to the base plate 10 is located below the base plate. That is, the bottom end of the first part 31 is positioned lower than the bottom end of the base plate in the height direction of the battery 20. This avoids the risk of the insulating adhesive 30 causing the battery cell 22 to be squeezed and fall off due to expansion, and provides more expansion space for the battery cell 22.

[0089] In an alternative embodiment, the battery 20 further includes terminals 24 located on the surface of the metal casing 23 facing the base plate 10. Terminals 24 can be understood, for example, as current output terminals of the battery 20, enabling series or parallel connection between adjacent batteries 20.

[0090] It is understandable that when the terminal post 24 is located on the surface of the metal casing 23 facing the base plate 10, the bonding area between the battery 20 and the base plate 10 will decrease accordingly, and the range of Equation 1 can be appropriately adjusted. The inventors discovered that when Equation 1 satisfies the following relationship, it can ensure both the bonding strength between the battery 20 and the base plate 10 and the insulation effect between adjacent batteries 20. At this time, the insulating layer 21 and the insulating adhesive 30 satisfy: 0.015mm≤[(2D1+D2) / 2L]×H≤2.5mm (8) For ease of description, the above relationship is referred to as Equation 8. When Equation 8 satisfies the above range, it can ensure a stable bond between the battery 20 and the base plate 10, and at the same time, it can also ensure the insulation effect between two adjacent batteries 20.

[0091] Alternatively, the terminal 24 is located on the surface of the metal casing 23 facing away from the base plate 10. That is, the terminal 24 is located on the top surface of the metal casing 23. In this case, the distance between the terminal 24 and the first exposed area of ​​the bottom surface 233 is relatively large, avoiding the risk of short circuit between the terminal 24 and the first exposed area. In this way, the range of Equation 1 can be appropriately adjusted to reserve more expansion space between adjacent batteries 20 while ensuring insulation effect. At this time, the insulating layer 21 and the insulating adhesive 30 can satisfy: 0.001mm≤[(2D1+D2) / 2L]×H≤2.2mm (9).

[0092] For ease of description, the above relationship is referred to as Equation 9. When Equation 9 satisfies the above range, it can ensure the electrical safety of battery 20. At the same time, it can also ensure that there is sufficient expansion space between two adjacent batteries 20 to avoid the explosion valve from abnormally opening due to insufficient expansion space.

[0093] <Example Electrical Equipment> This invention also provides an electrical device that may include the battery pack 100 described above.

[0094] By way of example only, electrical equipment can be, but is not limited to, vehicles, ships, aircraft, household appliances, and industrial equipment. For example, vehicles can be passenger cars, trucks, construction vehicles, etc.

[0095] The following specific embodiments will illustrate the effects of insulating layer 21 and insulating adhesive 30 on the insulation performance of battery 20 and thermal runaway.

[0096] Battery manufacturing methods: The battery can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this embodiment is not limited to this. A battery typically includes a battery casing, a cell, an adapter plate, and an electrolyte. The battery casing is used to house the cell and the electrolyte. The battery casing generally includes a casing body and a cover plate, with at least one positive electrode post and at least one negative electrode post disposed on the casing and / or the cover plate. The cell includes one or more electrode assemblies, which are formed by stacking or winding positive electrode plates, negative electrode plates, and a separator. The separator is located between adjacent positive and negative electrode plates to insulate them, and at least one end of the electrode assembly has a tab. One end of the adapter plate is electrically connected to the tab, and the other end is electrically connected to the electrode post.

[0097] Taking a wound battery cell as an example, the specific manufacturing process is as follows: Positive electrode sheets, negative electrode sheets, and a separator are wound to form an electrode assembly. A tab is led out from one end of the electrode assembly. When fixing the tab to the adapter plate, the electrode assembly and tab are first placed along the tab's lead-out direction. Then, the tab of the electrode assembly is welded to the tab welding area of ​​the adapter plate. Subsequently, the adapter plate and the electrode post on the cover plate are welded to the electrode post welding area of ​​the adapter plate. After welding, the electrode post and tab are located on the same side in the thickness direction of the adapter plate. Then, the electrode assembly is folded along the connection point between the tab and the electrode assembly. This positions the electrode assembly and electrode post on opposite sides in the thickness direction of the adapter plate. The folded electrode assembly is then inserted into the casing, and the cover plate is welded and sealed to the battery casing body. Electrolyte injection, formation, and sealing of the injection hole yield a single battery cell.

[0098] Test method: Multiple sets of batteries, each containing 45 cells, were fabricated using conventional methods. All cells in each set were identical in performance and structural parameters except for their cell size L. An insulating layer, for example, an insulating film of a specific material, was attached to each of the four sides of the cells. This insulating film, except for its thickness D1, had identical performance, structural parameters, and attachment area. To facilitate recording the opening pressure during thermal runaway testing, pressure sensors were installed inside each cell during the fabrication process.

[0099] A batch of battery boxes with the same structural dimensions and materials were selected. Forty-five sample batteries from each group were arranged in rows of 15 along the width of the battery and packed into the boxes. Three rows were installed within each battery box, and the boxes were bonded to the battery base plate using polyurethane structural adhesive. The adhesive layer thickness on the bottom of the battery was 1.5 mm. The thickness D2 and height H of the first part of the insulating adhesive between adjacent batteries within each battery pack were different. The assembled battery packs were placed in a 45°C environment and left to stand for 48 hours to obtain the sample battery packs. The specific selection of the parameters L, D1, D2, and H is detailed in Table 1.

[0100] 1. Insulation test: Insulation withstand voltage tests were performed on the batteries in the aforementioned sample battery packs. The positive and negative interfaces of the insulation withstand voltage tester were connected to the exposed portions of the cover plates of two adjacent sample batteries, specifically the locations where the QR codes protrude from the battery cover. The withstand voltage tester was set to the 4000V DC voltage range for 60 seconds, and the maximum leakage current during the test was recorded in mA. Ten sets of measurements were randomly taken from each sample battery pack; any battery pack with a leakage current exceeding 0.5 mA was considered a failure.

[0101] 2. Thermal runaway test: Thermal runaway tests were performed on five areas within each of the aforementioned battery pack samples. Specifically, the four corners and the middle of the battery pack were selected, and the pressure at which the battery's explosion-proof valves opened in each of the five areas was recorded. The maximum pressure was subtracted from the minimum pressure; a difference greater than 0.4 MPa was considered a failure. This demonstrates that abnormal pressure release within the battery pack led to a significant deviation in the battery's explosion pressure, affecting the battery pack's performance.

[0102] The specific testing method is as follows: fully charge the battery pack to 100% SOC, let it stand for 24 hours to ensure stable voltage and temperature, and the ambient temperature is 25℃.

[0103] Table 1. Specific parameters and test results for each embodiment. Install the heating device at the center of the first wall (large surface) of the target battery, and tightly attach a high-temperature heating element. The high-temperature heating element has a power of 150W and a temperature resistance of 500℃. Fix the high-temperature heating element to the first wall with high-temperature tape, ensuring there are no gaps between them. Connect the heating element's power cord to an external programmable power supply to heat the target battery at a constant power of 150W. If the battery temperature ≥150℃ and the temperature rise rate >1℃ / s, or if the voltage drops sharply by >20%, the battery is considered to have thermal runaway. The internal pressure sensor records the burst pressure.

[0104] Following the above plan, a brand new battery pack of the same specifications was used, with identical heating element positions / power and sensor arrangements. Another area out of the five areas of the battery pack was selected for testing, and the same steps were repeated. This enabled the thermal runaway valve opening pressure test of the five areas within the same battery pack to be performed, and the differences in thermal runaway characteristics and explosion-proof valve opening pressures between different areas were analyzed.

[0105] According to the test results in Table 1, the performance parameters of the selected test sample batteries in Examples 1 to 17 meet the following condition: 0.001 ≤ ((2D1+D2) / 2L)×H ≤ 2.5. In the insulation test, all requirements were met. That is, the leakage current between any two adjacent test sample batteries was less than 0.5mA, meeting the insulation performance requirements. In the thermal runaway test, when the batteries in the five zones of the sample battery pack experienced thermal runaway, the explosion pressure difference between any two adjacent test sample batteries was less than 0.4MPa. This proves that the battery operating environment inside the battery pack is normal, the battery explosion-proof valve pressure is normal, and the design requirements are met.

[0106] In Examples 13 to 17, the selected test sample batteries met the following performance parameters: 0.001 ≤ ((2D1+D2) / 2L)×H ≤ 2.5, all of which met the test requirements for insulation testing and thermal runaway testing. However, it was found that the selection of parameters such as D1, D2, H, and L also had a certain impact on the battery performance. Specifically: In Examples 14 and 17, D1 is smaller, posing a risk of the insulation layer being punctured during battery assembly. Furthermore, the expansion and compression of the insulation film during battery use poses a risk of insulation film failure.

[0107] In Examples 15 to 17, D2 is larger. During testing, it was found that the size of multiple batteries increased when placed into the pack, requiring a larger pre-tightening force to hold the batteries. At the same time, the distance between two adjacent batteries is larger, reducing the number of batteries that can be assembled in the same battery pack, and the energy density of the battery pack is relatively lower; heat dissipation during battery use is also affected to some extent.

[0108] In Example 13, D2 is relatively small. When the batteries are assembled into the box, the first part of the insulating adhesive between two adjacent batteries is easily squeezed and thinned, which poses a certain risk of insulation failure.

[0109] In Examples 13 and 16, L is smaller, and a larger number of batteries can be assembled in the same battery box. The battery casing occupies a larger space, resulting in a larger battery pack weight.

[0110] In Example 15, L is relatively large, resulting in a larger battery width, making it difficult to assemble the battery when placing it into the box during the manufacturing process.

[0111] In Examples 13 and 16, H is smaller, increasing the risk of insulation failure between two adjacent batteries.

[0112] In Examples 14 and 17, H is relatively large, resulting in a large constraint area when the battery expands, which affects the battery's charging and discharging performance.

[0113] In Comparative Examples 1 to 3, the performance parameters of the selected test sample batteries met the following range: ((2D1+D2) / 2L)×H<0.001. In the thermal runaway test, when the batteries in the five zones of the sample battery pack experienced thermal runaway, the burst pressure difference between any two batteries was less than 0.4 MPa, proving that the battery operating environment inside the battery pack was normal, the battery burst valve pressure was normal, and the design requirements were met. However, in the insulation test, the leakage current between adjacent batteries was greater than 0.5 mA, indicating that the insulation performance of the tested sample batteries did not meet the design requirements.

[0114] In Comparative Examples 4 to 6, the performance parameters of the selected test sample batteries met the following range: ((2D1+D2) / 2L)×H>2.5. In the insulation test, all met the requirements; the leakage current between any two adjacent tested sample batteries was less than 0.5mA, satisfying the insulation performance requirements. However, in the thermal runaway test, when the batteries in the five zones of the sample battery pack experienced thermal runaway, the burst pressure difference between any two adjacent batteries was greater than 0.4MPa. This indicates that the burst pressure of the batteries in the sample battery pack is abnormal, and the valve opening pressure of some sample batteries is affected during operation, failing to meet the thermal runaway design requirements.

[0115] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0116] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are meant to be within the scope of the invention and form different embodiments.

[0117] Those skilled in the art will understand that although the invention has been described with reference to exemplary embodiments, various changes may be made and its elements may be substituted with equivalents without departing from the scope of the invention. Furthermore, many modifications may be made to adapt particular situations or materials to the teachings of the invention without departing from the essential scope of the invention.

Claims

1. A battery pack, characterized in that, include: Base plate; Multiple batteries are arranged and fixedly mounted on the base plate along a first direction. Each battery includes a metal casing, which includes two opposing first walls and two opposing second walls. The area of ​​the first walls is larger than the area of ​​the second walls. In the multiple batteries, the first walls of two adjacent batteries are arranged opposite each other. An insulating layer is provided on the outer surface of the first wall. The first direction is perpendicular to the first wall. The insulating layer partially covers the first wall, giving the first wall a second exposed area. The first portion at least partially covers the second exposed area. The metal casing also includes a bottom surface, which faces the base plate and has a first exposed area. The insulating adhesive includes a first part and a second part. The first part is disposed between two adjacent batteries and fixes the two adjacent batteries in place. At least a portion of the second part is disposed between the first exposed area and the base plate and fixes the batteries and the base plate in place. It also includes a barrier element located between the first wall portions of two adjacent batteries, a portion of which is fixedly connected to the insulating adhesive; The insulating layer and the insulating adhesive satisfy the following: 0.001mm≤[(2D1+D2) / 2L]×H≤2.5mm Wherein, D1 is the thickness of the insulating layer in the first direction, in mm; D2 is the thickness of the first part in the first direction, in mm; L is the length of the battery in the first direction, in mm; and H is the distance between the top of the first part and the top surface of the base plate, in mm.

2. The battery pack as described in claim 1, characterized in that, The insulating layer completely covers the first wall portion, and the insulating layer and the insulating adhesive satisfy the following: 0.001mm≤[(2D1+D2) / 2L]×H≤2.1mm.

3. The battery pack as described in claim 2, characterized in that, The insulating layer extends to the bottom surface.

4. The battery pack as described in claim 3, characterized in that, In the first direction, the ratio of the extension dimension C of the insulating layer on the bottom surface to the dimension L is 0.02 ≤ C / L ≤ 0.

3.

5. The battery pack as described in claim 4, characterized in that, In the first direction, the extension dimension C of the insulating layer on the bottom surface ranges from 1mm to 10mm.

6. The battery pack as described in claim 1, characterized in that, The value of H ranges from 5mm to 20mm.

7. The battery pack as described in claim 1, characterized in that, The first part completely covers the second exposed area.

8. The battery pack as claimed in claim 1, characterized in that, The first wall portions of two adjacent batteries, arranged opposite each other, are each provided with a second exposed area, and the insulating layer and the insulating adhesive satisfy the following: 0.05mm≤[(2D1+D2) / 2L]×H≤2.5mm.

9. The battery pack as claimed in claim 1, characterized in that, The elastic modulus of the first part is less than that of the second part.

10. The battery pack as claimed in claim 1, characterized in that, In a direction perpendicular to the base plate, the edge of the insulating layer disposed on the first wall portion, parallel to and close to the bottom surface, has a first gap with the bottom surface, and the insulating layer and the insulating adhesive satisfy the following: 0.01mm≤[(2D1+D2) / 2L]×H≤2.5mm.

11. The battery pack as claimed in claim 3, characterized in that, In the direction perpendicular to the base plate, H is greater than the height of the first interval.

12. The battery pack as claimed in claim 10, characterized in that, In the direction perpendicular to the base plate, the height of the first interval ranges from 0.1mm to 0.3mm.

13. The battery pack as claimed in claim 1, characterized in that, The dielectric constant of the insulating adhesive ranges from 2F / m to 5.5F / m.

14. The battery pack as claimed in claim 1, characterized in that, It also includes a barrier element located between the first wall portions of two adjacent batteries; The barrier component and the insulating adhesive do not come into contact.

15. The battery pack according to any one of claims 1-14, characterized in that, The battery also includes a cell, which is disposed inside the metal casing. In the direction perpendicular to the base plate, the height of the cell is M, in mm, and the value of the H / M ratio ranges from 0.002 to 0.

15.

16. The battery pack according to any one of claims 1-14, characterized in that, The battery also includes an explosion-proof valve, which is disposed on the bottom surface. The insulating layer and the insulating adhesive satisfy the following: 0.15mm≤[(2D1+D2) / 2L]×H≤2.5mm.

17. The battery pack as claimed in claim 16, characterized in that, The insulating adhesive is provided with a hollow structure at the position opposite to the explosion-proof valve to expose the explosion-proof valve.

18. The battery pack as claimed in claim 15, characterized in that, The battery cell includes a base plate located between the bottom surface of the battery cell and the metal casing.

19. The battery pack as claimed in claim 18, characterized in that, The first portion, at the end furthest from the base plate, is located above the base plate, and the insulating layer and the insulating adhesive satisfy the following: 0.001mm≤[(2D1+D2) / 2L]×H≤2.0mm.

20. The battery pack as claimed in claim 18, characterized in that, The end of the first portion near the base plate is located below the base plate.

21. The battery pack as claimed in claim 1, characterized in that, The battery further includes terminals located on the surface of the metal casing facing the base plate, and the insulating layer and the insulating adhesive satisfy the following: 0.015mm≤[(2D1+D2) / 2L]×H≤2.5mm.

22. The battery pack as claimed in claim 1, characterized in that, The battery further includes terminals located on the surface of the metal casing facing away from the base plate, and the insulating layer and the insulating adhesive satisfy the following: 0.001mm≤[(2D1+D2) / 2L]×H≤2.2mm.

23. The battery pack as claimed in claim 1, characterized in that, The entire bottom surface is set as the first exposed area, and the insulating layer and the insulating adhesive satisfy the following: 0.04mm≤[(2D1+D2) / 2L]×H≤2.5mm.

24. The battery pack as claimed in claim 1, characterized in that, The insulating layer satisfies: 0.05mm≤D1≤0.2mm.

25. The battery pack as claimed in claim 1, characterized in that, The insulating adhesive satisfies the following: 0.2mm≤D2≤0.7mm, and / or 0.5mm≤H≤20mm.

26. The battery pack as claimed in claim 1, characterized in that, The battery satisfies: 25mm≤L≤150mm.

27. The battery pack as claimed in claim 1, characterized in that, The multiple batteries are square batteries.

28. An electrical appliance, characterized in that, Includes the battery pack as described in any one of claims 1-14.

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