Heat insulation pad, battery pack and vehicle

Abstract

The utility model relates to a heat insulation pad, a battery pack and a vehicle, and the heat insulation pad comprises a frame and a core body; the core body comprises a heat insulation part and a liquid absorption part, the liquid absorption rate of the liquid absorption part is larger than that of the heat insulation part, and the frame is arranged in the circumferential direction of the core body and fixed to the core body. The heat insulation pad can realize heat insulation and cooling effects between the large surfaces of the battery cells, so that the safety of the battery pack is ensured, and the situation that the thickness of the heat insulation pad is relatively large and the occupied space is relatively large can be avoided.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, specifically to a heat insulation pad, a battery pack, and a vehicle. Background Technology

[0002] Thermal insulation pads are placed between the battery cells. These pads prevent the rapid transfer of high temperatures to surrounding cells in the event of thermal runaway in a single cell, thus avoiding a chain reaction that could ultimately lead to a fire or explosion of the entire battery pack, thereby improving safety. Furthermore, the thermal insulation pads fill the gaps between the cells, enhancing the overall structural stability of the battery pack and making it more resistant to external impacts and vibrations. The thermal insulation pads also possess a degree of elasticity and cushioning, absorbing volume changes that occur during charging and discharging and reducing vibration and friction between the cells. In addition, they provide some electrical insulation, preventing short circuits between the cells.

[0003] In existing technologies, thermal insulation pads mainly use core materials with low thermal conductivity, such as aerogel and nanoplates, to achieve thermal insulation. When a cell experiences thermal runaway, the thermal insulation effect of the aerogel controls the surface temperature of adjacent cells, ensuring that adjacent cells are not triggered into thermal runaway. However, with changes in the cell system, the ejector temperature during cell thermal runaway is becoming increasingly higher. To ensure safety, the thickness of the core material needs to be increased to achieve better thermal insulation, which occupies space within the battery pack and affects the cell arrangement.

[0004] Therefore, how to ensure the safety of the battery pack while avoiding the large space occupied by the thick heat insulation pad is a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] The purpose of this application is to provide a heat insulation pad, a battery pack, and a vehicle that can ensure the safety of the battery pack while avoiding the situation where the heat insulation pad occupies a large amount of space due to its large thickness.

[0006] To solve the above-mentioned technical problems, this application provides a heat insulation pad, including a frame and a core; the core includes a heat insulation part and a liquid absorption part, the liquid absorption rate of the liquid absorption part is greater than the liquid absorption rate of the heat insulation part, and the frame is arranged along the circumference of the core and fixed to the core.

[0007] Optionally, the bottom of the liquid-absorbing portion extends to the bottom end face of the core.

[0008] Optionally, the liquid-absorbing part includes at least one of a capillary structure, a water-absorbing bead, and a water-absorbing resin component.

[0009] Optionally, the heat insulation part and the liquid absorption part are spliced ​​together along the height direction, and the liquid absorption part is located below the heat insulation part.

[0010] Optionally, the top of the liquid-absorbing part is provided with a groove that is adapted to the heat-insulating part, and the heat-insulating part is located in the groove.

[0011] Optionally, the ratio of the volume of the heat insulation part to the volume of the core is not less than 2 / 5;

[0012] And / or, the ratio of the height of the heat insulation portion to the height of the core is not greater than 2 / 3.

[0013] Optionally, the liquid-absorbing part and the heat-insulating part are spliced ​​together along the length direction, and there are two liquid-absorbing parts, with the heat-insulating part disposed between the two liquid-absorbing parts.

[0014] Optionally, the total length of the two liquid-absorbing portions is greater than the total length of the heat-insulating portion, and the length of the heat-insulating portion is not less than 2 / 5 of the total length of the core.

[0015] Optionally, the lower side wall of the heat insulation part is provided with a first step structure, the liquid absorption part is in contact with the step surface of the first step structure, and the side surface of the liquid absorption part away from the step surface is aligned with the side wall surface of the heat insulation part.

[0016] Optionally, the top side wall of the liquid absorption part is provided with a second step structure, and the step surface of the second step structure is in contact with the step surface of the first step structure.

[0017] Optionally, the number of the frame edges is two, and the core is sandwiched between the two frame edges;

[0018] Alternatively, the core is located within the area enclosed by the frame, and the thickness of the core is less than the thickness of the frame.

[0019] Optionally, the core body is further wrapped with a first encapsulation layer, and there are two borders, which are respectively located in the core body and fixed to the first encapsulation layer.

[0020] Optionally, the number of the borders is one, the core is located within the area enclosed by the borders, and the thickness of the core is less than the thickness of the borders.

[0021] Optionally, it further includes a second encapsulation layer, which is encapsulated outside the frame and the core to fix the frame and the core.

[0022] This application also provides a battery pack, including battery cells and a heat insulation pad as described above, the heat insulation pad being sandwiched between the large surfaces of two adjacent battery cells.

[0023] This application also provides a vehicle including the battery pack described above.

[0024] The heat insulation pad, battery pack, and vehicle provided in this application have the following technical advantages compared to existing solutions:

[0025] Liquids are excellent phase change materials. When individual cells experience thermal runaway, the temperature inside the battery pack rises sharply. The liquid absorbed in the liquid absorbent section absorbs heat and evaporates, changing from a liquid state to a gaseous state. Since the liquid needs to absorb heat during the process of changing from a liquid state to a gaseous state, it can effectively reduce the temperature of adjacent cells.

[0026] When the core is configured to include a heat insulation section and a liquid absorption section, the heat insulation section provides heat insulation, while the liquid absorption section absorbs liquid and actively cools the cell by absorbing a large amount of heat when the liquid evaporates into vapor in the event of thermal runaway, preventing heat propagation. This ensures safety during thermal runaway while maintaining the same core thickness, avoiding the situation where the heat insulation pad occupies a large space in the battery pack and affects the cell arrangement. With the same battery pack size, more cells can be arranged, which helps to improve the energy density of the battery pack and thus improve the vehicle's range. Attached Figure Description

[0027] Figure 1 This is an exploded view of the heat insulation pad and battery cell provided in the embodiments of this application;

[0028] Figure 2 This is a top view of the structure of the heat insulation pad at the factory.

[0029] Figure 3 yes Figure 2 Exploded view;

[0030] Figure 4 This is a structural diagram of the first arrangement of the core;

[0031] Figure 5 This is a structural diagram of the second arrangement of the core;

[0032] Figure 5a yes Figure 5 Schematic diagram of the liquid absorption section;

[0033] Figure 6 This is a structural diagram of the third arrangement of the core;

[0034] Figure 7 This is a structural diagram of the fourth arrangement of the core;

[0035] Figure 7a yes Figure 7 Schematic diagram of the structure of the central heat insulation section;

[0036] Figure 8 This is a structural diagram of the fifth arrangement of the core;

[0037] Figure 8a yes Figure 8 Schematic diagram of the structure of the central heat insulation section;

[0038] Figure 8b yes Figure 8 Schematic diagram of the liquid absorption section;

[0039] Figure 9 This is a top view of the insulation pad with two borders, after removing the encapsulation layer;

[0040] Figure 10 yes Figure 9 Exploded view;

[0041] Figure 11 This is a cross-sectional view of the frame and core in the installed state when the heat insulation pad has two frames;

[0042] Figure 12 This is a schematic diagram of the structure of a heat insulation pad with a border, after removing the encapsulation layer;

[0043] Figure 13 This is a schematic diagram of the border structure.

[0044] Appendix Figures 1-13 The reference numerals in the attached figures are explained as follows:

[0045] 10 heat insulation pads; 20 battery cells; 201 large surface area;

[0046] 1. Border;

[0047] 2 core, 21 heat insulation part, 211 first step structure, 22 liquid absorption part, 221 groove, 222 second step structure, 231 first part, 232 second part, 233 third part, 24 first encapsulation layer;

[0048] 3 Second encapsulation layer, 31 Recessed structure;

[0049] 4. Second adhesive layer;

[0050] 5 release layers, 51 operating ears;

[0051] 6. First adhesive layer. Detailed Implementation

[0052] To enable those skilled in the art to better understand the technical solutions of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0053] This application provides a heat insulation pad, a battery pack, and a vehicle. The vehicle includes a battery pack containing multiple battery cells 20 arranged in parallel. The large surfaces 201 (the side wall with the largest area) of two adjacent parallel battery cells 20 are positioned opposite each other. Furthermore, as... Figure 1As shown, a heat insulation pad 10 is installed between two adjacent battery cells 20. This heat insulation pad 10 serves to insulate the cells 20 from heat in the event of thermal runaway in a single cell 20, preventing rapid heat transfer to adjacent cells and thus avoiding a chain reaction. This reduces the probability of the entire battery pack catching fire or exploding, improving safety. Furthermore, the heat insulation pad 10 also provides electrical insulation, preventing short circuits between the cells 20.

[0054] like Figure 2 and Figure 3 As shown, the heat insulation pad 10 includes a frame 1 and a core 2. The frame 1 is arranged circumferentially along the core 2. The core 2 includes a heat insulation part 21 and a liquid absorption part 22. The liquid absorption rate of the liquid absorption part 22 is greater than that of the heat insulation part 21. Taking volumetric liquid absorption rate as an example, volumetric liquid absorption rate refers to the ratio of the volume of liquid absorbed by the liquid absorption part 22 under certain conditions to the volume of the liquid absorption part 22 under dry conditions. It is usually expressed as a percentage. The fact that the liquid absorption rate of the liquid absorption part 22 is greater than that of the heat insulation part 21 means that, under the same volume and conditions, the amount of liquid absorbed by the liquid absorption part 22 is greater than that absorbed by the heat insulation part 21.

[0055] The liquid absorption section 22 has a relatively strong liquid absorption effect. Compared with the aerogel heat insulation pad used in the prior art, it has a stronger liquid absorption capacity. In this embodiment, there is no limitation on the liquid absorbed by the absorption section 22. It can be water, ethanol, ethylene glycol, and mixtures, etc. For example, in the processing, storage or use environment, the liquid absorption section 22 can absorb moisture in the air. Or, if a spray device is installed in the battery pack, after individual cells 20 experience thermal runaway, the temperature inside the battery pack rises sharply. The high temperature can melt the spray device inside the battery pack, causing the spray device to spray coolant into the battery pack. The liquid absorption section 22 can absorb the coolant sprayed by the spray device.

[0056] Liquids are excellent phase change materials. When individual cells 20 experience thermal runaway, the temperature inside the battery pack rises sharply. The liquid absorbed in the liquid absorbent section 22 absorbs heat and evaporates, changing from a liquid to a gaseous state. Since the liquid absorbs heat during the evaporation process, it can effectively reduce the temperature of adjacent cells. Taking water as an example, water's maximum temperature at normal atmospheric pressure is 100°C. Absorbing heat will only cause it to boil and vaporize, without raising its temperature. Therefore, the evaporation of water absorbed by the liquid absorbent section 22 can reduce the temperature inside the battery pack. Before the water in the liquid absorbent section 22 completely evaporates, the maximum temperature of adjacent cells 20 will not exceed 100°C. This effectively prolongs the time before adjacent cells 20 experience thermal runaway, reduces the probability of heat propagation, lowers the probability of the entire battery pack catching fire or exploding, and improves safety.

[0057] Specifically, taking water as an example of liquid absorbed by the liquid absorption part 22, the dimensions of the liquid absorption part 22 are 95.2mm × 205mm × 3.6mm. If its volumetric water absorption rate can reach 78%, and it absorbs 50g of water, the total amount of heat that 50g of water can absorb when it rises from an initial temperature of 50℃ to boiling at 100℃ is:

[0058] Heat absorbed during temperature rise: 4.2 (specific heat capacity of water) × 50g × 50℃ = 10500J = 10.5kJ;

[0059] Boiling endothermic reaction: 2260 (heat capacity of vaporization) × 50g = 113000J = 113kJ;

[0060] Total heat absorbed = 10.5 + 113 = 123.5 kJ;

[0061] Assuming a specific heat of 1, if the mass of cell 20 is 2.3 kg, the heat absorbed by the liquid-absorbing part 22 when 50 g of water completely changes from liquid to gas can reduce the temperature of a single cell 20 by 53.7 °C, which is a significant cooling effect.

[0062] The phase change of water allows for rapid heat absorption during thermal runaway. Water has a latent heat of 2260 kJ / kg. The more water absorbed, the more heat is carried away during thermal runaway, effectively preventing heat propagation and improving overall package safety.

[0063] With the changes in the battery cell 20 system, the temperature emitted during thermal runaway of the battery cell 20 is also increasing. To ensure safety, the requirements for the thermal insulation performance of the heat insulation pad 10 between the battery cells 20 are also higher. Compared with the traditional heat insulation pad 10 that only uses aerogel components, when the core body 2 is configured to include a heat insulation part 21 and a liquid absorption part 22, the heat insulation part 21 plays a role in heat insulation, and the liquid absorption part 22 absorbs liquid and absorbs a large amount of heat by the liquid evaporating into vapor during thermal runaway, thereby actively cooling the battery cell 20 and preventing heat spread. This can ensure safety during thermal runaway when the core body 2 has the same thickness, and avoid the situation where the heat insulation pad 10 occupies a large space in the battery pack and affects the arrangement of the battery cells 20. With the same battery pack size, more battery cells 20 can be arranged, which is conducive to improving the energy density of the battery pack and thus improving the vehicle's range.

[0064] In this embodiment, the heat insulation part 21 can be made of aerogel (such as glass fiber aerogel, ceramic fiber aerogel), nanoplate, etc., and the liquid absorption part 22 has a higher liquid absorption rate than the heat insulation part 21. Specifically, a component with a volume liquid absorption rate of not less than 30% can be selected. There are no specific limitations on the structure and material of the liquid absorption part 22. The liquid absorption part 22 can absorb liquid physically or chemically. When the liquid absorption part 22 absorbs liquid physically, it can be at least one of capillary structures and water-absorbing beads. When the liquid absorption part 22 absorbs liquid chemically, it can include a water-absorbing resin component. Specifically, the liquid absorption part 22 can simultaneously employ both physical and chemical water absorption methods.

[0065] When the liquid-absorbing part 22 includes a capillary structure, it can adsorb liquid through capillary action. Specifically, the liquid-absorbing part 22 can be fluff pulp, which forms micropores through plant fibers and quickly adsorbs liquid through capillary action. The liquid-absorbing part 22 can also be a sponge, which has small channels in a porous structure that generate capillary force to absorb liquid. Alternatively, the liquid-absorbing part 22 can also be glass fiber needle-punched felt, ceramic fiber, etc. When the liquid-absorbing part 22 includes water-absorbing beads, it can adsorb liquid through the surface of the water-absorbing beads or trap liquid through pores. The liquid-absorbing part 22 can be silica gel desiccant, with a high specific surface area porous structure (pore size 2nm-3nm) that physically adsorbs liquid molecules. The liquid-absorbing part 22 can also be zeolite (molecular sieve), which has a regular microporous structure (0.3nm-10nm). The absorbent part 22 can selectively adsorb small molecule liquids (nm). It can also be activated alumina, where the porous alumina surface adsorbs liquids through polar interactions. When the absorbent part 22 includes a liquid-absorbing resin component, it can lock in water through chemical bonds or ionic interactions. Specifically, the absorbent part 22 can include sodium polyacrylate (SAP), where sodium carboxylate ions in the cross-linked polymer chain form hydrogen bonds with water, absorbing up to 100 times their own weight in liquid. It can also be polyvinyl alcohol (PVA), where hydroxyl groups form hydrogen bonds with water molecules, swelling into a gel after absorbing liquid. Alternatively, it can be polyacrylamide (PAM), which binds to water through amide groups and is used as a water-retaining agent or thickener. In other words, the absorbent part 22 can be made of any absorbent material with a water absorption rate ≥100%, such as gels, fibers, felts, sponges, or absorbent resins.

[0066] In this embodiment, the specific structure and position of the heat insulation part 21 and the liquid absorption part 22 are not limited. Preferably, the bottom of the liquid absorption part 22 extends downward to the bottom end face of the core 2. "Down" means that the heat insulation pad 10 is facing the bottom of the battery pack when in use. When the spraying device sprays coolant, the coolant gathers at the bottom of the battery pack. The bottom of the liquid absorption part 22 extending to the bottom end face of the core 2 facilitates the rapid absorption of the coolant at the bottom, further improving the cooling effect.

[0067] The specific arrangement of the heat insulation part 21 and the liquid absorption part 22 is not limited, including but not limited to, such as Figures 4-7 The five arrangement methods are shown.

[0068] like Figure 4 In the first arrangement shown, the heat insulation part 21 and the liquid absorption part 22 can be spliced ​​vertically along the height direction. Both the heat insulation part 21 and the liquid absorption part 22 are regular square structures, which are simple in structure and have high material utilization. The height of the heat insulation part 21 is a, the height of the liquid absorption part 22 is b, and the total height of the core 2 is a+b. The ratio of the height of the liquid absorption part 22 to the total height of the core 2 is not less than 1 / 3, that is, b / (a+b) ≥1 / 3, to ensure that the liquid absorption part 22 can absorb a sufficient amount of liquid to ensure that the cooling effect is achieved through liquid evaporation.

[0069] like Figure 5 and Figure 5a In the second arrangement shown, the top of the liquid-absorbing part 22 has an upward-opening groove 221, meaning the liquid-absorbing part 22 has an upward-opening U-shaped structure. The size and shape of the groove 221 are adapted to the heat insulation part 21, and the heat insulation part 21 is located exactly within the groove 221. Essentially, the liquid-absorbing part 22 surrounds the bottom and left and right sides of the heat insulation part 21. The liquid-absorbing part 22 is configured as a structure including a first section, a second section, and a third section arranged in the left-right direction. The first, second, and third sections can be an integral structure or a separate structure. The first and third sections are located on the sides of the heat insulation part 21, and the second section is located at the bottom of the heat insulation part 21. The bottoms of the first, second, and third sections extend downwards to the bottom end face of the core 2. The large volume of the liquid-absorbing part 22 effectively ensures the liquid absorption effect, thereby ensuring the cooling effect of the battery cell 20 through liquid evaporation.

[0070] Specifically, the width of the first and third segments is *c*, the width of the second segment and the heat insulation part 21 is *d*, the height of the heat insulation part 21 is *e*, and the volume of the heat insulation part 21 is no less than 2 / 5 of the volume of the core 2 to ensure the heat insulation effect. Furthermore, the height *e* of the heat insulation part 21 is no more than 2 / 3 of the total height of the core 2 to ensure the liquid absorption effect of the liquid absorption part 22. With this configuration, the heat insulation part 21 can cover the middle position and the upper part of the battery cell 20 in the height direction. In the event of thermal runaway, the heat insulation part 21 is close to the highest temperature point of the battery cell 20, blocking heat transmission and improving safety.

[0071] Of course, in this embodiment, the heat insulation part 21 can also be set as a T-shaped structure, that is, the top of the first segment and the third segment can also be provided with the heat insulation part 21. And if the heat insulation part 21 is completely set in the groove 221, its structure is square and the structure is simpler.

[0072] like Figure 6In the third arrangement shown, the heat insulation part 21 and the liquid absorption part 22 are spliced ​​along the left and right direction. In the embodiment shown in the figure, one heat insulation part 21 is set between two liquid absorption parts 22. The width of the heat insulation part 21 is g, and the width of the two liquid absorption parts 22 is f. That is, the two liquid absorption parts 22 are symmetrically arranged on both sides of the heat insulation part 21. The total width of the liquid absorption part 22 is 2f. The total length of the core 2 in the left and right direction is g+2f. The total length of the liquid absorption part 22, 2f, is not less than the length g of the heat insulation part 21. Furthermore, the ratio of the length g of the heat insulation part 21 to the total length of the core 2 is not less than 2 / 5, that is, 2f≥g≥2 / 5(g+2f), so as to ensure the heat insulation effect and the liquid absorption effect.

[0073] Of course, there can also be two heat insulation parts 21 and one liquid absorption part 22 located between the two heat insulation parts 21, or one heat insulation part 21 and one liquid absorption part 22 spliced ​​together in the left and right direction, or the number of heat insulation parts 21 and the number of liquid absorption parts 22 can also be other numbers.

[0074] The two liquid absorption parts 22 are located on both sides of the heat insulation part 21, which simplifies the overall structure. The liquid absorption parts 22 are symmetrically arranged on both sides of the heat insulation part 21, which can further ensure the effect of liquid evaporation and heat absorption to reduce the temperature of the battery cell 20 when thermal runaway occurs. In addition, the heat insulation part 21 is located in the middle of the core 2. When the battery cell 20 experiences thermal runaway, the heat insulation part 21 is close to the highest temperature point of the battery cell 20 at the time of thermal runaway, which is conducive to achieving the heat insulation effect and ensuring safety.

[0075] like Figure 7 and Figure 8 As shown, the heat insulation part 21 and the liquid absorption part 22 also include portions that are stacked along the thickness direction.

[0076] Specifically, such as Figure 7 and Figure 7a In the fourth arrangement shown, a first step structure 211 is also provided on the lower side wall of the heat insulation part 21. The liquid absorption part 22 is attached to the step surface of the first step structure 211, and the side surface of the liquid absorption part 22 away from the step surface is aligned with the side wall surface of the heat insulation part 21. That is to say, the upper part of the core 2 is the heat insulation part 21, and the lower part is a structure in which the heat insulation part 21 and the liquid absorption part 22 are spliced ​​together in the thickness direction. At this time, the heat insulation part 21 has a structure similar to an inverted L-shape.

[0077] Or, it could also be like Figure 8 , Figure 8a , Figure 8bIn the fifth arrangement shown, a first step structure 211 is provided on the lower side wall of the heat insulation part 21, and a second step structure 222 is provided on the top side wall of the liquid absorption part 22. The step surfaces of the first step structure 211 and the second step structure 222 are in contact. That is, the core 2 includes a first part 231, a second part 232, and a third part 233 arranged sequentially from top to bottom. The first part 231 is the heat insulation part 21, the third part 233 is the liquid absorption part 22, and the second part 232 is formed by splicing the heat insulation part 21 and the liquid absorption part 22. The thickness of the heat insulation part 21 and the liquid absorption part 22 in the second part can be the same. In this case, both the heat insulation part 21 and the liquid absorption part 22 have a similar L-shaped structure.

[0078] Alternatively, the core 2 can be formed entirely by splicing the heat insulation part 21 and the liquid absorption part 22 along the thickness direction. Figure 7 and Figure 8 The solution shown can ensure the liquid absorption capacity of the bottom liquid absorption part 22 while also ensuring the heat insulation capacity of the top heat insulation part 21, thus providing higher safety.

[0079] Of course, in this embodiment, the specific shapes of the heat insulation part 21 and the liquid absorption part 22 are not limited, and can be any shape such as triangle, trapezoid, square, circle, etc.

[0080] The frame 1 is arranged circumferentially along the core 2, serving as a buffer and support between the two cells 20, filling the gap between them, and enhancing the overall structural stability of the battery pack, making it more resistant to external impacts and vibrations. The frame 1 is preferably a plastic frame 1, although the material is not limited; plastic can also be used. The plastic frame 1 provides sufficient support strength while also exhibiting elasticity and buffering capacity through deformation, absorbing volume changes during charging and discharging, and reducing vibration and friction between the cells 20.

[0081] The side wall of the large surface 201 of the core 2 facing the cell 20 does not protrude from the side wall of the frame 1. The frame 1 can play a buffering and supporting role between the two cells 20, while the middle position of the frame 1 can also provide space for the cell 20 to bulge.

[0082] The number of borders 1 can be as follows Figure 9 and Figure 10 As shown in the two examples, the core 2 is sandwiched between the two side frames 1. In other words, the side frames 1, core 2, and side frames 1 are stacked in sequence. At this time, the core 2 has a larger area and better heat insulation and cooling effect.

[0083] Furthermore, when there are two borders, such as Figure 11As shown, the heat insulation pad 10 also includes a first encapsulation layer 24, which wraps around the core 2 and is fixed to the frame 1. The first encapsulation layer 24 can provide protection for the core 2 and facilitates fixation to the frame 1. After thermal runaway occurs, the temperature rises and the first encapsulation layer 24 is heated and cracks, and the water-absorbing core leaks out, which can absorb liquid from the outside.

[0084] The first encapsulation layer 24 and the frame 1 are bonded and fixed together by the first adhesive layer 6. The first adhesive layer 6 can be double-sided tape or the like. Bonding and fixing the first encapsulation layer 24 and the frame 1 together by the first adhesive layer 6 can simplify the fixing process.

[0085] The number of borders can also be one, such as... Figure 2 , Figure 3 and Figure 12 As shown, the frame 1 is a square frame formed by four sides connected end to end. The core 2 is located within the space of this square frame, and the thickness of the core 2 is less than the thickness of the frame 1, so that the sidewalls of the core 2 do not protrude from the sides of the frame 1. In the event of thermal runaway, liquid can enter the space formed by the frame 1 and the two battery cells 20. The core 2 is located within this space, and the liquid absorption part 22 can absorb the liquid that enters the space. With this configuration, the thickness of the frame 1 and the width of each side can be designed according to the spacing between the two battery cells 20 and the design requirements of the supporting force. The structure of the frame 1 is as follows. Figure 13 As shown, the dimensions of the four sides of border 1 can be the same or different, and can be set according to the actual situation.

[0086] Furthermore, when the number of border 1s is one, such as Figure 2 and Figure 3 As shown, the heat insulation pad 20 also includes a second encapsulation layer 3, which can be encapsulated around the frame 1 and the core 2 to fix the frame 1 and the core 2 into a plate-like structure. The second encapsulation layer 3 can play a fixing role to fix the frame 1 and the core 2, ensuring stability in the installed state. At the same time, the second encapsulation layer 3 can also prevent the problem of insulation withstand voltage failure of the entire package.

[0087] When there is only one frame 1, the thickness of the frame 1 is greater than the thickness of the core 2. The second encapsulation layer 3 has two layers, and the two second encapsulation layers 3 are respectively encapsulated on both sides of the frame 1 and the core 2, which can form a recessed structure 31 at the inner edge of the frame 1.

[0088] The materials of the first encapsulation layer 24 and the second encapsulation layer 3 are not limited; they can be PET, PC, or PE layers, etc.

[0089] The heat insulation pad 10 is sandwiched between the large surfaces 201 of the two battery cells 20. To ensure stability during installation, the heat insulation pad 10 can be fixed between the side wall of the heat insulation pad 10 and the large surface 201 of the battery cell 20 by a second adhesive layer 4. The second adhesive layer 4 can be a double-sided adhesive layer. The adhesive layer 4 is arranged along the circumference of the heat insulation pad 10, specifically along the circumference of the frame 1, and located on the outer surface of the frame 1 or the outer surface of the second encapsulation layer 3.

[0090] When the heat insulation pad 10 leaves the factory, if Figure 2 and Figure 3 As shown, the second adhesive layer 4 can be directly applied to the outer surface of the heat insulation pad 10. The heat insulation pad 10 also includes two release layers 5, which are respectively applied to both sides of the heat insulation pad 10 and fixed by the second adhesive layer 4. That is to say, at the factory, the two release layers 5 provide protection for the second adhesive layer 4 on both sides of the heat insulation pad 10. During installation, the operator can directly remove the release layer 5 and attach it to the large surface 201 of the battery cell 20 through the second adhesive layer 4. The installation operation is relatively convenient and facilitates the improvement of battery pack assembly efficiency.

[0091] And, as Figure 2 and Figure 3 As shown, the release layer 5 also has an operating ear 51 extending outward from its side. During installation, the operating ear 51 can be used to act on the release layer 5 to detach it from the second adhesive layer 4. Specifically, the operating ear 51 can be formed by extending outward from the edge of any position in the circumference of the release layer 5.

[0092] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0093] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0094] The above are merely preferred embodiments of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A heat insulation pad, characterized in that, Includes the border (1) and the core (2); The core (2) includes a heat insulation part (21) and a liquid absorption part (22). The liquid absorption rate of the liquid absorption part (22) is greater than that of the heat insulation part (21). The frame (1) is arranged along the circumference of the core (2) and fixed to the core (2).

2. The heat insulation pad according to claim 1, characterized in that, The bottom of the liquid absorption part (22) extends to the bottom end face of the core (2).

3. The heat insulation pad according to claim 1, characterized in that, The liquid-absorbing part (22) includes at least one of capillary structure, water-absorbing beads and water-absorbing resin component.

4. The heat insulation pad according to any one of claims 1-3, characterized in that, The heat insulation part (21) and the liquid absorption part (22) are spliced ​​along the height direction, and the liquid absorption part (22) is located below the heat insulation part (21).

5. The heat insulation pad according to any one of claims 1-3, characterized in that, The top of the liquid absorption part (22) is provided with a groove (221) that is adapted to the heat insulation part (21), and the heat insulation part (21) is located in the groove (221).

6. The heat insulation pad according to claim 5, characterized in that, The ratio of the volume of the heat insulation part (21) to the volume of the core (2) is not less than 2 / 5; And / or, the ratio of the height of the heat insulation part (21) to the height of the core (2) is not greater than 2 / 3.

7. The heat insulation pad according to any one of claims 1-3, characterized in that, The liquid absorption part (22) and the heat insulation part (21) are spliced ​​together along the length direction, and there are two liquid absorption parts (22), with the heat insulation part (21) located between the two liquid absorption parts (22).

8. The heat insulation pad according to claim 7, characterized in that, The total length of the two liquid absorption parts (22) is greater than the total length of the heat insulation part (21), and the length of the heat insulation part (21) is not less than 2 / 5 of the total length of the core (2).

9. The heat insulation pad according to any one of claims 1-3, characterized in that, The lower side wall of the heat insulation part (21) is provided with a first step structure (211), the liquid absorption part (22) is in contact with the step surface of the first step structure (211), and the side surface of the liquid absorption part (22) away from the step surface is aligned with the side wall surface of the heat insulation part (21).

10. The heat insulation pad according to claim 9, characterized in that, The top side wall of the liquid absorption part (22) is provided with a second step structure (222), and the step surface of the second step structure (222) is in contact with the step surface of the first step structure (211).

11. The heat insulation pad according to any one of claims 1-10, characterized in that, The core (2) is also wrapped with a first encapsulation layer (24), and there are two borders (1). The two borders (1) are located on the core (2) and fixed to the first encapsulation layer (24).

12. The heat insulation pad according to any one of claims 1-10, characterized in that, The number of the frame (1) is one, the core (2) is located in the area enclosed by the frame (1), and the thickness of the core (2) is less than the thickness of the frame (1).

13. The heat insulation pad according to claim 12, characterized in that, It also includes a second encapsulation layer (3), which is encapsulated outside the frame (1) and the core (2) to fix the frame (1) and the core (2).

14. A battery pack, characterized in that, It includes a battery cell (20) and a heat insulation pad as described in any one of claims 1-13, the heat insulation pad being sandwiched between the large surfaces (201) of two adjacent battery cells (20).

15. A vehicle, characterized in that, Includes the battery pack as described in claim 14.

Images