Battery pack and powered device

Abstract

The present disclosure provides a battery pack and an electric device. The battery pack comprises a box, a plurality of batteries and a buffer frame. The box is internally provided with a box space. The plurality of batteries are accommodated in the box space, each battery comprising a cell and a shell accommodating the cell, the cell comprising at least one thinned portion, and the shell comprising a large face, two large faces of two adjacent batteries being opposite. The buffer frame is arranged between the two batteries and comprises a plurality of frame bodies arranged in a rectangle, the plurality of frame bodies comprising at least one first frame body and at least one second frame body, and the orthographic projection of each thinned portion on the large face at least partially overlaps the orthographic projection of the corresponding first frame body on the large face. In the case that the buffer frame is compressed and deformed by the two batteries, the pressure intensity of each first frame body applied to the large face is P1, in units of MPa, and the pressure intensity of each second frame body applied to the large face is P2, in units of MPa, P1>P2. While the thinned portion provides a pre-tightening force, the cell or the shell is prevented from being damaged or deformed due to excessive compression.

Description

Technical Field

[0001] This disclosure relates to the field of batteries, and in particular, to a battery pack and an electrical device having the battery pack. Background Technology

[0002] Batteries are typically made by stacking or winding multiple electrodes. During electrode manufacturing, the coated active material slurry is fluid before curing, naturally leveling and forming a gradually thinning edge at the boundary with the uncoated foil area. Because this thinning edge is located on the tab side during stacking, the overall thickness of the tab side of the cell is smaller than other areas of the cell due to the multiple layers of electrodes. When housing the batteries in a casing, multiple batteries can be stacked along the thickness direction, meaning that the large surfaces of adjacent batteries are in contact. Simultaneously, buffer pads or buffer frames are placed between the large surfaces of adjacent batteries to provide necessary pre-tightening force during stacking and prevent the batteries from scattering.

[0003] However, due to insufficient thickness of the thinned portion, the internal structure of the cell on the tab side is loose, and a tight interface contact cannot be formed between the positive electrode, negative electrode and the separator. Utility Model Content

[0004] In view of this, the present disclosure provides a battery pack designed to solve the problem that insufficient thickness of the thinned portion leads to a loose internal structure of the cell on the tab side, resulting in the inability to form a tight interfacial contact between the positive electrode, negative electrode and separator.

[0005] The battery pack includes a housing, multiple batteries, and a buffer frame. The housing has an internal space. Multiple batteries are housed within the internal space. Each battery includes a cell and a housing. The cell includes at least one thinned portion, and the housing includes a large surface, with the two large surfaces of adjacent batteries facing each other. A buffer frame is positioned between two batteries and includes multiple frames arranged in a rectangle. These frames include at least one first frame and at least one second frame. The orthographic projection of each thinned portion onto the large surface at least partially overlaps with the orthographic projection of the corresponding first frame onto the large surface. When the buffer frame is compressed and deformed by two batteries, each first frame exerts a pressure of P1 (in MPa) on the large surface, and each second frame exerts a pressure of P2 (in MPa), where P1 > P2.

[0006] A battery cell can be composed of multiple electrodes and separators stacked together. The internal structure of the cell in the thinned section is relatively loose, and gaps may exist between the electrodes and separators. When the battery is constrained within the casing and the buffer frame is compressed and deformed, the pressure P1 applied to the large surface by each first frame is greater than the pressure P2 applied by each second frame. This results in the first frame with a higher pressure P1 being applied to the thinned section of the cell, effectively compacting the side of the cell with the thinned section, ensuring close contact between the loose electrodes and separators, and suppressing the risk of lithium plating. Meanwhile, other areas are fitted with second frames with a lower pressure P2, providing the necessary pre-tightening force to prevent the battery from scattering while avoiding damage to the internal structure of the cell or deformation of the casing due to excessive compression, ultimately optimizing the overall safety and durability of the battery pack. Attached Figure Description

[0007] It should be understood that the following figures only illustrate certain embodiments of this disclosure and should not be construed as limiting the scope.

[0008] It should be understood that the same or similar reference numerals are used in the accompanying drawings to denote the same or similar elements.

[0009] It should be understood that the accompanying drawings are only schematic, and the dimensions and scales of the elements in the drawings are not necessarily precise.

[0010] Figure 1 This is a schematic diagram of the structure of a battery pack according to an embodiment of the present disclosure.

[0011] Figure 2 for Figure 1 A schematic diagram of the structure of the battery and buffer frame.

[0012] Figure 3 for Figure 2 A schematic diagram of the structure of the battery.

[0013] Figure 4 for Figure 2 A schematic diagram of the structure of the battery and buffer frame.

[0014] Figure 5 This is a schematic diagram of the structure of a buffer frame according to another embodiment of the present disclosure.

[0015] Figure 6 for Figure 4 A magnified view of part A in the middle.

[0016] Figure 7 for Figure 5 A magnified view of part B in the middle section.

[0017] Figure 8 This is a schematic diagram of the structure of a battery according to another embodiment of the present disclosure.

[0018] Figure 9This is a schematic diagram of the structure of a battery and a buffer frame according to another embodiment of the present disclosure.

[0019] Figure 10 This is a schematic diagram of the structure of a buffer frame according to another embodiment of the present disclosure.

[0020] Figure 11 This is a schematic diagram of the structure of a battery according to another embodiment of the present disclosure.

[0021] Figure 12 This is a schematic diagram of the structure of a battery and a buffer frame according to another embodiment of the present disclosure.

[0022] Figure 13 This is a schematic diagram of the structure of a buffer frame according to another embodiment of the present disclosure.

[0023] Figure 14 for Figure 4 A magnified view of part A in the middle.

[0024] Figure 15 for Figure 2 A schematic diagram of the structure of the buffer frame.

[0025] Figure 16 This is a partial cross-sectional view of an electrical appliance according to an embodiment of the present disclosure.

[0026] Figure captions: 100—Battery pack; 10—Box; 20—Battery; 21—Battery cell; 21a—Wound battery cell; 211—Thinning section; 211a—Inner edge of thinning section; 22—Shell; 221—Large surface; 221a—Corresponding side of large surface; 30—Buffer frame; 31—Frame; 311—First frame; 311a—Outer edge of first frame; 311b—Inner edge of first frame; 312—Second frame; 313—Side frame; 313a—Bottom end face of side frame; 313b—Inner side face of side frame; 314—Bottom frame; 314a—Upper side face of bottom frame; 314b—One end face of bottom frame; 315—Top frame; 200—Electrical equipment. Detailed Implementation

[0027] Numerous specific details are set forth below to provide an understanding of the structure, function, and use of the embodiments described and illustrated in the specification and figures. It is to be understood that the embodiments described and illustrated herein are non-limiting examples, and thus it will be appreciated that the particular structural and functional details disclosed herein are representative and exemplary. Variations and changes may be made to these embodiments without departing from the scope of the claims.

[0028] <Example Battery Pack> This disclosure provides a battery pack according to one embodiment. (See reference...) Figure 1The battery pack 100 includes a housing 10 and multiple batteries 20. The multiple batteries 20 are electrically connected to each other to form a battery pack. The housing 10 houses the batteries 20 and a battery management system. The batteries 20 are electrically connected to the battery management system to enable the charging and discharging of the multiple batteries 20. The housing 10 serves as an external protective structure, typically made of metal or composite materials, and is waterproof, dustproof, and impact-resistant, providing a safe operating environment for the internal components such as the batteries 20 and the battery management system.

[0029] The battery pack 100 may also include a battery group composed of multiple batteries 20 connected in series and parallel, and integrate a battery management system (BMS), a thermal management system, an electrical connection system (high-voltage / low-voltage connectors, wiring harnesses, etc.), structural components (casing, brackets, etc.), and protective components. These components are housed within the enclosure 10 and sealed by the top cover, forming a complete functional unit capable of directly outputting electrical energy. The battery pack 100 can serve as a rechargeable battery pack, acting as a power source for new energy vehicles, primarily for storing and providing electrical energy.

[0030] refer to Figures 2 to 4 The battery pack 100 also includes a buffer frame 30. The housing 10 has an internal space. Multiple batteries 20 are housed within the internal space. Each battery 20 includes a cell 21 and a housing 22 containing it. The cell 21 includes at least one thinned portion 211, and the housing 22 includes a large surface 221. The two large surfaces 221 of adjacent batteries 20 face each other. The buffer frame 30 is disposed between two batteries 20 and includes multiple frames 31 arranged in a rectangle. Each frame 31 includes at least one first frame 311 and at least one second frame 312. The orthographic projection of each thinned portion 211 onto the large surface 221 at least partially overlaps with the orthographic projection of the corresponding first frame 311 onto the large surface 221. When the buffer frame 30 is compressed and deformed by the two batteries 20, the pressure exerted on the large surface 221 by each first frame 311 is P1 (MPa), and the pressure exerted on the large surface 221 by each second frame 312 is P2 (MPa), where P1 > P2.

[0031] Figure 3 , Figure 8 and Figure 11 The figures show three structural diagrams of battery 20. In other diagrams including buffer frame 30, the tabs 23 are not shown to more clearly illustrate the assembly relationship and internal layout of buffer frame 30 and cell 21. This is a simplification for illustration and does not mean that tabs 23 are absent in the actual product or that there is no corresponding tab design at that location. The thinned portion 211 is the shaded area in the diagram.

[0032] The battery cell 21 can be formed by stacking multiple electrodes and multiple separators. The internal structure of the battery cell 21 in the thinned section 211 is relatively loose, and there may be gaps between the electrodes and separators. When the battery 20 is constrained within the housing 10 and the buffer frame 30 is compressed and deformed, the pressure P1 applied to the large surface 221 by each first frame 311 is greater than the pressure P2 applied by each second frame 312. This causes the first frame 311 with a higher pressure P1 to be applied to the thinned section 211 of the battery cell 21, thereby effectively compacting the side of the battery cell 21 with the thinned section 211, making the loose electrodes and separators come into close contact, and suppressing the risk of lithium plating. Other areas are provided with second frames 312 with a lower pressure P2, which provide the necessary pre-tightening force to prevent the battery 20 from falling out, while avoiding damage to the internal structure of the battery cell 21 or deformation of the housing 22 due to excessive compression, ultimately optimizing the overall safety and durability of the battery pack 100.

[0033] For ease of description, in the accompanying drawings of this disclosure, arrows X+ and X- respectively indicate opposite sides in the height direction, arrows Y+ and Y- respectively indicate opposite sides in the width direction, and arrows Z+ and Z- respectively indicate opposite sides in the thickness direction.

[0034] Continue to refer to Figures 2 to 4 Under a pressure of 1 MPa along the thickness direction of the buffer frame 30, the compression ratio of the first frame 311 is C1, and the compression ratio of the second frame 312 is C2, where C1 < C2. Since the adhesion between the electrode and separator layers in the thinned portion 211 region of the cell 21 is weak, gaps are prone to appear during cycling, inducing lithium plating. The first frame 311, with its lower compression ratio C1, provides higher structural rigidity to the thinned portion 211, resulting in less deformation and effectively maintaining close contact between the electrode and separator, thus ensuring the stability of the lithium-ion transport channel. In other areas of the cell 21, where the electrode and separator layers are denser, the second frame 312, with its larger compression ratio C2, can generate greater deformation under pressure. This not only absorbs and disperses mechanical stress but also provides appropriate pre-tightening force for the entire battery 20, preventing excessive constraint from causing hard compression of the cell 21.

[0035] Further, 0.011≤C1 / C2≤0.97, preferably 0.1≤C1 / C2≤0.9. More preferably, 0.2≤C1 / C2≤0.8. Alternatively, the ratio C1 / C2 can also be 0.3, 0.4, 0.5, 0.6, or 0.7. If C1 / C2 is too small, i.e., C1 / C2 is less than 0.011, the stiffness difference between the first frame 311 and the second frame 312 is large. When the battery 20 expands during charging and discharging, the deformation of the thinned portion 211 is excessively restricted, while the deformation of the surrounding area is large. This may cause the electrode at the edge of the thinned portion 211 to be subjected to excessive shear stress, which may lead to tearing or damage. If C1 / C2 is too large, i.e., C1 / C2 is greater than 0.97, the stiffness difference between the first frame 311 and the second frame 312 is small. The first frame 311 cannot provide sufficient rigid support to effectively suppress the formation of gaps inside the thinned section 211. The thinned section 211 may still develop gaps due to excessive deformation during cycling, and the risk of lithium plating cannot be effectively suppressed. According to the above ratio range, it is ensured that the first frame 311 provides sufficient rigid support for the thinned section 211, effectively compacting the electrode and separator to prevent gap formation. At the same time, it is ensured that the second frame 312 provides sufficient buffer for other areas of the cell 21, absorbing energy and dispersing stress.

[0036] Furthermore, 1% ≤ C1 ≤ 30%, preferably 5% ≤ C1 ≤ 25%. More preferably, 10% ≤ C1 ≤ 20%. Alternatively, the value of C1 can also be 12%, 14%, 16%, or 18%, etc. 20% ≤ C2 ≤ 90%. Preferably, 30% ≤ C2 ≤ 80%. More preferably, 40% ≤ C2 ≤ 70%. Alternatively, the value of C2 can also be 45%, 50%, 55%, 60%, or 65%, etc.

[0037] Continue to refer to Figures 2 to 4 The first frame 311 can be made of solid silicone, foamed silicone, resin, ceramic fiber aerogel, pre-oxidized fiber aerogel, or glass fiber aerogel. The second frame 312 can be made of foamed silicone, microporous foamed polypropylene, foamed polyimide, ceramic fiber aerogel, pre-oxidized fiber aerogel, glass fiber aerogel, ceramic fiber mat, or glass fiber mat. Based on these materials, the first frame 311 has a low compressibility, suppressing local deformation of the thinned portion 211 and providing sufficient rigid support. Based on these materials, the second frame 312 has a high compressibility, absorbing and dispersing the expansion stress generated by the battery 20 during charging and discharging, providing excellent flexible buffering.

[0038] refer to Figure 2 , Figure 4 and Figure 15In its uncompressed state, the thickness of the first frame 311 is T1 (mm), and the thickness of the second frame 312 is T2 (mm), where T1 > T2. That is, the first frame 311 and the second frame 312 can be made of the same material, and the thickness of the first frame 311 is greater than that of the second frame 312. When the battery pack 100 is installed into the housing 10 and secured, the buffer frame 30 is subjected to overall compression. At this time, the thicker first frame 311 will be compressed preferentially or more, resulting in a greater pre-compression in the thinned portion 211 area of ​​the cell 21. This allows the first frame 311, even when made of the same material as the other frames 31, to exert a higher initial pre-tightening force on the large surface 221 of the housing 22 due to its larger initial deformation, providing stronger basic support for the thinned portion 211. In another embodiment, the first frame 311 and the second frame 312 may be made of different materials, the compression ratio of the first frame 311 is less than that of the second frame 312, and the thickness of the first frame 311 is greater than that of the second frame 312.

[0039] Further, 1 ≤ T1 / T2 ≤ 2, preferably 1.1 ≤ T1 / T2 ≤ 1.9. More preferably, 1.2 ≤ T1 / T2 ≤ 1.8. Alternatively, the ratio T1 / T2 can also be 1.3, 1.4, 1.5, 1.6, or 1.7. If T1 / T2 is too small, i.e., T1 / T2 is less than 1, the thickness difference between the first frame 311 and the second frame 312 is insufficient. After compression, the difference in preload generated by the first frame 311 and the second frame 312 is not significant enough, weakening the compaction effect on the thinned portion 211. If T1 / T2 is too large, i.e., T1 / T2 is greater than 2, the thickness difference between the first frame 311 and the second frame 312 will be too large. During the fastening process of the housing 10, the excessively thick first frame 311 will be over-compressed, possibly reaching its compression limit, leading to plastic deformation or even crushing failure. At the same time, the second frame 312 cannot provide effective pre-tightening force and buffering function, putting the battery 20 at risk of being loose or insufficiently constrained in other areas of the cell 21. Based on the above ratio, it is ensured that the first frame 311 can generate a higher pre-compression amount and initial pre-tightening force than the second frame 312 after assembly, ensuring that the thinned part 211 can obtain rigid support, and also ensuring that the second frame 312 can be moderately compressed, so that the entire cell 21 is subjected to a uniform overall pre-tightening force.

[0040] Furthermore, 0.2mm ≤ T1 ≤ 10mm, preferably 0.5mm ≤ T1 ≤ 9mm. More preferably, 1mm ≤ T1 ≤ 8mm. Alternatively, the value of T1 can also be 2mm, 4mm, 6mm, or 7mm, etc. 0.2mm ≤ T2 ≤ 10mm. Preferably, 0.5mm ≤ T2 ≤ 9mm. More preferably, 1mm ≤ T2 ≤ 8mm. Alternatively, the value of T2 can also be 2mm, 4mm, 6mm, or 7mm, etc.

[0041] The first frame 311 and the second frame 312 can be made of the same material. This can reduce the manufacturing cost of the buffer frame 30 and simplify the process complexity. When the battery 20 expands and contracts during cycling, the buffer frame 30, made of the same material, can deform in a coordinated and uniform manner with the battery 20, dispersing mechanical stress and avoiding the formation of local stress concentration points on the surface of the cell 21.

[0042] The first frame 311 and the second frame 312 can both be made of solid silicone, foamed silicone, resin, ceramic fiber aerogel, pre-oxidized fiber aerogel, glass fiber aerogel, microporous foamed polypropylene, or foamed polyimide. Based on these materials, the overall elasticity and cushioning of the buffer frame 30 can be maintained, preventing indentations or damage to the surface of the housing 22 due to excessive localized hardness when the buffer frame 30 is compressed.

[0043] The length direction of each thinned portion 211 is the same as the length direction of the corresponding first frame 311. (See reference) Figure 4 The length direction of the thinned portion 211 is the height direction of the battery (i.e., the X+-X- direction). (Reference) Figure 4 and Figure 5 The first frame 311 consists of two side frames 313, and the second frame consists of a bottom frame 314 and a top frame 315. (Reference) Figure 9 and Figure 10 The length direction of the thinned part 211 is the width direction of the battery (i.e., the Y+-Y- direction), the first frame 311 is the top frame 315, and the second frame is two side frames 313 and a bottom frame 314.

[0044] refer to Figure 4 and Figure 5At least one thinning portion 211 may include two thinning portions 211, which are respectively located at both ends of the cell 21 in the width direction of the battery 20. At least one first frame 311 includes two side frames 313, which are spaced apart along the width direction and perpendicular to the width direction. That is, the positive and negative tabs 23 of the cell 21 are respectively located on both sides of the electrode in the width direction. This makes the cell 21 have relatively loose internal structure and weak interlayer adhesion on both sides of the width direction. Correspondingly, the buffer frame 30 also has two side frames 313 arranged at intervals along the width direction, which respectively cover the two thinning portions 211. The two side frames 313 apply the same rigid constraint to the thinning portions 211 on both sides of the width direction of the cell 21, which can effectively balance the expansion and contraction stress on both sides of the electrode during charging and discharging, prevent the cell 21 from twisting or unilateral overvoltage, and improve the structural stability and cycle life of the cell 21.

[0045] refer to Figure 4 and Figure 6 At least one second frame 312 may include a bottom frame 314 and a top frame 315 spaced apart along the height direction of the battery 20 and perpendicular to the height direction, with the bottom end face 313a of each side frame 313 facing the upper side face 314a of the bottom frame 314. This construction prevents the solid structural adhesive applied to the bottom plate of the housing 10 from seeping upwards into the joints of the buffer frame 30 before curing, thereby preventing it from spreading to the large surfaces 221 of adjacent batteries 20, ensuring a clean battery 20 interface, and avoiding interference with heat dissipation or unnecessary internal stress due to adhesive intervention.

[0046] refer to Figure 5 and Figure 7 In another embodiment, at least one second frame 312 may include a bottom frame 314 and a top frame 315 spaced apart along the height direction of the battery 20 and perpendicular to the height direction, with the inner surface 313b of each side frame 313 facing one end face 314b of the bottom frame 314. The first frame 311 may completely cover the thinned portion 211, allowing for better and tighter contact between the loose electrode and the separator, suppressing the risk of lithium plating.

[0047] refer to Figure 8 and Figure 9The buffer frame 30 may include a top frame 315, a bottom frame 314, and two side frames 313 arranged in a rectangle. The top frame 315 and the bottom frame 314 are spaced apart along the height direction and perpendicular to the height direction. The two side frames 313 are spaced apart along the width direction of the battery 20 and perpendicular to the width direction. At least one first frame 311 includes the top frame 315, and at least one thinning portion 211 includes a thinning portion 211 located at the top of the cell 21. That is, the positive and negative electrode tabs 23 of the cell 21 are located on one side of the electrode sheet in the height direction, i.e., the top side. This makes the cell 21 form a thinning portion 211 with a relatively loose internal structure and weak interlayer adhesion on the top side. Correspondingly, the first frame 311 is also provided in the top frame 315 to better cover the thinning portion 211.

[0048] Continue to refer to Figure 9 At least one second frame 312 may include two side frames 313 and a bottom frame 314. That is, the top frame 315 is the first frame 311, and the two side frames 313 and the bottom frame 314 are the second frames 312. The top frame 315 provides higher pressure, effectively compacting the loose electrode sheets and separator at the top, ensuring a stable lithium-ion transport channel. During the charging and discharging process of the battery 20, the two side frames 313 and the bottom frame 314 undergo moderate expansion deformation, releasing the stress inside the battery 20.

[0049] refer to Figure 10 At least one first frame 311 may also include two side frames 313, and at least one second frame 312 includes a bottom frame 314. That is, the top frame 315 and the two side frames 313 constitute the first frame 311, and the bottom frame 314 constitutes the second frame 312. When the battery 20 expands during cycling, the first frame 311 can effectively constrain the cell 21 in the main expansion direction during charging and discharging, namely the thickness and width directions, avoiding the risk of damage to the tab 23 area or cracking of the casing 22 that may result from the concentration of all stress in the top frame 315.

[0050] refer to Figure 11 and Figure 12The battery cell 21 can be a wound battery cell 21a, which includes a flat portion 212a and two curved portions 213a located at both ends along its width direction. The orthographic projection of each side frame 313 on the large surface 221 at least partially overlaps with the orthographic projection of the corresponding curved portion 213a on the large surface 221. Since the curved portions 213a at both ends of the width direction of the wound battery cell 21a pose a risk of loose internal structure of the electrode and separator and uneven interface pressure, by using the two side frames 313 as the first frame 311 corresponding to the projection of the curved portion 213a, a higher pressure P1 can be applied to the curved portion 213a, effectively constraining the deformation of the curved portion 213a during cycling, compacting the electrode and separator, suppressing lithium plating caused by loose interface, and jointly maintaining the overall compactness and interface stability of the wound battery cell 21a, thereby improving the cycle life and safety of the battery 20.

[0051] refer to Figure 13 In another embodiment, at least one first frame 311 may further include a bottom frame 314, and at least one second frame 312 may include two side frames 313. That is, the top frame 315 and the bottom frame 314 constitute the first frame 311, and the two side frames 313 constitute the second frame 312. This can evenly distribute the internal pressure of the battery 20 and prevent problems such as deformation of the casing 22, deterioration of interface contact, or risk of localized lithium plating caused by stress concentration in the top frame 315.

[0052] refer to Figure 4 and Figure 5 The orthographic projection of the first frame 311 onto the large surface 221 completely covers the orthographic projection of the thinned portion 211 onto the large surface 221 along the width direction of the first frame 311. That is, the first frame 311 completely covers the thinned portion 211 in the width direction. Due to different splicing methods, refer to... Figure 4 The first frame 311 may not completely cover the thinned portion 211 in the height direction, see reference. Figure 5 The first frame 311 can completely cover the thinned part 211 in the height direction.

[0053] refer to Figure 14The distance d1, in mm, is the distance from the orthographic projection of the outer edge 311a of the first frame 311 onto the corresponding side 221a of the large surface 221, where 0.5mm ≤ d1 ≤ 10mm. Preferably, 1mm ≤ d1 ≤ 9mm. More preferably, 2mm ≤ d1 ≤ 8mm. Alternatively, d1 can be 3mm, 4mm, 5mm, 6mm, or 7mm. If d1 is too small, i.e., less than 0.5mm, the first frame 311 is too biased towards the edge of the cell 21, which may result in insufficient coverage of the thinned portion 211. If d1 is too large, i.e., greater than 10mm, the coverage area of ​​the first frame 311 is too narrow towards the center of the large surface 221 of the battery 20, too far from the edge. The first frame 311 cannot cover the edge area near the tab 23, lacking sufficient constraint and easily causing gaps. Based on the aforementioned proportional range, the rigid support of the first frame 311 is ensured to fully cover all high-risk areas of the thinned portion 211 in the width direction. The distance between the orthographic projection of the inner edge 311b of the first frame 311 onto the large surface 221 and the orthographic projection of the inner edge 211a of the thinned portion onto the large surface 221 is d2, in mm, where 3mm ≤ d2 ≤ 30mm. Preferably, 5mm ≤ d2 ≤ 25mm. More preferably, 10mm ≤ d2 ≤ 20mm. Alternatively, the value of d2 can also be 12mm, 14mm, 16mm, or 18mm, etc. If d2 is too small, i.e., less than 3mm, the thinned portion 211 near the inner edge 311b of the first frame 311 will undergo relatively larger deformation due to insufficient constraint, which can easily lead to the separation of the electrode and the separator, creating a gap. Simultaneously, a small d2 places high demands on manufacturing and assembly tolerances; even minor alignment deviations may prevent the first frame 311 from completely covering the inner edge 211a of the thinned portion 211. If d2 is too large, i.e., greater than 30mm, this will cause part of the rigid support of the first frame 311 to be applied to the center of the cell 21, i.e., the area where the electrode and separator are pressed tightly together, potentially causing excessive constraint. Based on the above proportional range, it is ensured that the entire area of ​​the thinned portion 211 is effectively covered by the first frame 311, fundamentally suppressing the generation of gaps.

[0054] <Example Electrical Equipment> This utility model embodiment also provides an electrical device 200, which may include the battery pack 100 described above.

[0055] By way of example only, electrical equipment 200 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.

[0056] In addition, the electrical equipment 200 can also be used for the storage, conversion and release of recyclable electrical energy.

[0057] In a non-restrictive example, refer to Figure 16 The electrical equipment 200 can be the car 200, and the battery pack 100 can be used as a power source to power the car 200.

[0058] It should be noted that the elements described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0059] It should be understood that multiple components and / or parts can be provided by a single integrated component or part. Alternatively, a single integrated component or part can be divided into multiple separate components and / or parts. The use of the public designation "a" or "an" to describe a component or part does not imply the exclusion of other components or parts.

[0060] It should be understood that although terms such as “first” or “second” may be used in this disclosure to describe various elements (such as a first frame and a second frame), these elements are not defined by these terms, which are only used to distinguish one element from another.

[0061] The basic principles of this disclosure have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this disclosure are merely examples and not limitations, and should not be considered as essential features of each embodiment of this disclosure. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the scope of this disclosure to the necessity of employing the aforementioned specific details for implementation.

[0062] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A battery pack, characterized in that, include: The container has an internal space. Multiple batteries are housed within the box space. Each battery includes a cell and a housing containing it. The cell includes at least one thinned portion, and the housing includes a large surface, with two large surfaces of two adjacent batteries facing each other. as well as A buffer frame, disposed between the two batteries, includes a plurality of frames arranged in a rectangle, the plurality of frames including at least one first frame and at least one second frame, wherein the orthographic projection of each thinned portion on the large surface at least partially overlaps with the orthographic projection of the corresponding first frame on the large surface. When the buffer frame is compressed and deformed by the two batteries, the pressure applied to the large surface by each first frame is P1, in MPa, and the pressure applied to the large surface by each second frame is P2, in MPa, where P1 > P2.

2. The battery pack according to claim 1, characterized in that, Under a pressure of 1 MPa along the thickness direction of the buffer frame, the compression ratio of the first frame is C1, and the compression ratio of the second frame is C2, where C1 < C2.

3. The battery pack according to claim 2, characterized in that, 0.011≤C1 / C2≤0.97, and / or, 1%≤C1≤30%, and / or, 20%≤C2≤90%.

4. The battery pack according to claim 2 or 3, characterized in that, The first frame is made of solid silicone, foamed silicone, resin, ceramic fiber aerogel, pre-oxidized fiber aerogel or glass fiber aerogel, and / or the second frame is made of foamed silicone, microporous foamed polypropylene, foamed polyimide, ceramic fiber aerogel, pre-oxidized fiber aerogel, glass fiber aerogel, ceramic fiber mat or glass fiber mat.

5. The battery pack according to claim 1, characterized in that, In the uncompressed state, the thickness of the first frame is T1 in mm, and the thickness of the second frame is T2 in mm, where T1 > T2.

6. The battery pack according to claim 5, characterized in that, 1≤T1 / T2≤2, and / or, 0.2mm≤T1≤10mm, and / or, 0.2mm≤T2≤10mm.

7. The battery pack according to claim 5 or 6, characterized in that, The first frame and the second frame are made of the same material.

8. The battery pack according to claim 7, characterized in that, The first frame and the second frame are both made of solid silicone, foamed silicone, resin, ceramic fiber aerogel, pre-oxidized fiber aerogel, glass fiber aerogel, microporous foamed polypropylene or foamed polyimide.

9. The battery pack according to claim 1, characterized in that, The length direction of each thinning section is the same as the length direction of the corresponding first frame.

10. The battery pack according to claim 9, characterized in that, The at least one thinning portion includes two thinning portions, which are respectively located at both ends of the cell in the width direction of the battery. The at least one first frame includes two side frames, which are spaced apart along the width direction and perpendicular to the width direction.

11. The battery pack according to claim 10, characterized in that, The at least one second frame includes a bottom frame and a top frame spaced apart along the height direction of the battery and perpendicular to the height direction, with the bottom end face of each side frame facing the upper side face of the bottom frame.

12. The battery pack according to claim 10, characterized in that, The at least one second frame includes a bottom frame and a top frame spaced apart along the height direction of the battery and perpendicular to the height direction, with the inner side of each side frame facing one end face of the bottom frame.

13. The battery pack according to claim 9, characterized in that, The buffer frame includes a top frame, a bottom frame, and two side frames arranged in a rectangle. The top frame and the bottom frame are spaced apart along the height direction and perpendicular to the height direction. The two side frames are spaced apart along the width direction of the battery and perpendicular to the width direction. The at least one first frame includes the top frame. The at least one thinning portion includes a thinning portion located at the top of the battery cell.

14. The battery pack according to claim 13, characterized in that, The at least one second frame includes the two side frames and the bottom frame.

15. The battery pack according to claim 13, characterized in that, The at least one first frame also includes the two side frames, and the at least one second frame includes the bottom frame.

16. The battery pack according to claim 15, characterized in that, The battery cell is a wound battery cell, which includes a flat portion and two curved portions located at both ends along the width direction. The orthographic projection of each side frame on the large surface at least partially overlaps with the orthographic projection of the corresponding curved portion on the large surface.

17. The battery pack according to claim 13, characterized in that, The at least one first frame also includes the bottom frame, and the at least one second frame includes the two side frames.

18. The battery pack according to claim 9, characterized in that, The orthographic projection of the first frame on the large surface completely covers the orthographic projection of the thinned portion on the large surface along the width direction of the first frame.

19. The battery pack according to claim 18, characterized in that, The distance from the orthographic projection of the outer edge of the first frame onto the large surface to the corresponding side of the large surface is d1, in mm, where 0.5mm≤d1≤10mm; and / or, the distance from the orthographic projection of the inner edge of the first frame onto the large surface to the orthographic projection of the inner edge of the thinned portion onto the large surface is d2, in mm, where 3mm≤d2≤30mm.

20. An electrical appliance, characterized in that, Includes the battery pack according to any one of claims 1 to 19.

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