Heat absorption and insulation composite pad and battery module

Abstract

The invention relates to the technical field of battery flame-retardant materials, in particular to a heat-absorbing and heat-insulating composite pad and a battery module, the heat-absorbing and heat-insulating composite pad comprises an elastic heat-absorbing frame and at least one rigid heat-insulating plate, the elastic heat-absorbing frame is provided with a mounting port in a penetrating manner, and the rigid heat-insulating plate is arranged in the mounting port; the elastic heat absorption frame comprises a foam body and heat absorption bodies, a plurality of through holes are formed in the foam body in a penetrating mode, a plurality of closed holes are further formed in the foam body, the through holes and the closed holes are filled with the heat absorption bodies, and the surface of the foam body is covered with the heat absorption bodies. The rigid heat insulation plate is made of rigid heat insulation materials. The thickness of the elastic heat absorption frame is larger than that of the rigid heat insulation plate. The heat insulation pad can quickly and efficiently absorb heat and dissipate heat, effectively reduce the surface temperature of a thermal runaway battery cell, effectively buffer the expansion stress of the battery cell, reduce the thermal runaway risk of adjacent battery cells, and solve the problems that the surface temperature of the thermal runaway battery cell cannot be reduced, the expansion stress of the battery cell is difficult to effectively buffer, and the thermal runaway risk of the battery cell is increased; and the safety of the whole battery module is influenced.

Description

Technical Field

[0001] This invention relates to the field of battery flame retardant materials technology, and in particular to a heat-absorbing and heat-insulating composite pad and a battery module. Background Technology

[0002] As a core component of electric vehicles, battery modules primarily function to store, manage, and convert electrical energy. They are typically composed of numerous battery cells connected in series and parallel. During charging and discharging, battery cells (such as lithium-ion cells) expand in volume, compressing adjacent cells. Furthermore, external impacts, vibrations, packaging defects, or overcharging can all trigger thermal runaway in battery cells. Once thermal runaway occurs, the cell releases a large amount of heat; for example, the release temperature of ternary lithium batteries can exceed 1000℃, and lithium iron phosphate batteries can reach as high as 800℃. Under the influence of heat transfer, adjacent cells will successively experience thermal runaway, forming a chain reaction that may ultimately lead to battery module combustion or even explosion, increasing the safety risks of electric vehicles.

[0003] To address these risks, existing technologies typically place thermal insulation pads between adjacent cells to block heat transfer. However, with the widespread application of high-capacity cells (>500Ah), the heat generated by thermal runaway of these cells is several times greater than that of existing 280Ah and 314Ah cells.

[0004] Currently, battery cell heat insulation pads use a single aerogel material as the insulation material. Although its low thermal conductivity provides insulation, its high rigidity and low compressibility make it difficult for the heat insulation pad to absorb the expansion stress of the battery cell through its own elastic deformation. Moreover, aerogel materials, relying solely on insulation, can only alleviate the heat transfer rate of thermally runaway cells; over time, this will eventually induce thermal runaway in adjacent cells. Using polymer materials such as foam as separators between cells, while offering good elasticity and able to withstand the volume expansion and stress during normal charging and discharging, the poor heat resistance of polymers means that they will ignite when a cell is in thermal runaway, failing to prevent the spread of thermal runaway. Existing heat insulation pads cannot quickly and efficiently absorb and dissipate heat, cannot reduce the surface temperature of thermally runaway cells, and are ineffective in buffering the expansion stress of cells, increasing the risk of thermal runaway in adjacent cells, affecting the safety of the entire battery module, and even causing safety accidents. Summary of the Invention

[0005] In response to the problems raised in the background technology, the purpose of this invention is to provide a heat-absorbing and heat-insulating composite pad that can quickly and efficiently absorb and dissipate heat, effectively reduce the surface temperature of thermally runaway battery cells, inhibit the spread of heat diffusion, and effectively buffer the expansion stress of battery cells, preventing structural damage to adjacent battery cells due to expansion stress, and reducing the risk of thermal runaway in adjacent battery cells. This solves the problems of existing heat insulation pads that cannot quickly and efficiently absorb and dissipate heat, cannot reduce the surface temperature of thermally runaway battery cells, and are difficult to effectively buffer the expansion stress of battery cells, increasing the risk of thermal runaway in adjacent battery cells, affecting the safety of the entire battery module, and even causing safety accidents.

[0006] Another objective of this invention is to propose a battery module including the aforementioned heat-absorbing and heat-insulating composite pad. The heat-absorbing and heat-insulating composite pad can quickly and efficiently absorb and dissipate heat, effectively reducing the surface temperature of the thermal runaway cell, inhibiting the spread of heat diffusion, preventing adjacent cells from experiencing thermal runaway successively, and effectively buffering the expansion stress of the cell, preventing structural damage to adjacent cells due to expansion stress, and reducing the risk of thermal runaway in adjacent cells. This battery module has high safety and can effectively prevent safety accidents.

[0007] To achieve this objective, the present invention adopts the following technical solution: A heat-absorbing and heat-insulating composite pad includes an elastic heat-absorbing frame and at least one rigid heat-insulating plate. The elastic heat-absorbing frame has a through-hole, and the rigid heat-insulating plate is disposed in the through-hole. The four edges of the rigid heat-insulating plate are all fixed in the through-hole. The elastic heat-absorbing frame includes a foam body and a heat-absorbing body. The foam body is made of hydrophilic foam. The foam body has several through holes, and several adjacent through holes are interconnected. The foam body also has several closed pores inside. The heat-absorbing body is filled in several through holes and several closed pores. The surface of the foam body is covered with the heat-absorbing body. The heat-absorbing body is a cross-linked hydrogel material. The rigid heat insulation board is a rigid heat insulation material. The rigid heat insulation board is used to provide the battery cell with the functions of maintaining thickness, blocking heat and rigid protection, and the thickness of the elastic heat absorption frame is greater than the thickness of the rigid heat insulation board.

[0008] Optionally, the heat absorber is a glucomannan hydrogel; the elastic heat-absorbing frame further includes a first packaging body, which is a thermoplastic film material and completely wraps the foam body, and the first packaging body is used to seal and protect the foam body; The method for preparing the elastic heat-absorbing frame includes the following steps: Step S1: Prepare a dispersion suspension by mixing glucomannan and water evenly; prepare a crosslinking agent suspension by mixing crosslinking agent and water evenly. The crosslinking agent is selected from oxides of divalent metals or basic carbonates of divalent metals; Step S2: After heating the dispersion suspension, add the crosslinking agent suspension, maintain the temperature and stir evenly to prepare glucomannan aqueous slurry; Step S3: Maintain the temperature of step S2, immerse the foam body in the glucomannan aqueous slurry while it is still hot, and cool it to room temperature to obtain a mixture, the mixture including the foam body and the heat absorber; Step S4: The mixture is cured at room temperature for more than 24 hours to obtain an elastic cross-linked heat absorber; Step S5: Cut the cross-linked heat absorber according to the preset size and position to form the installation port, and then seal the cut cross-linked heat absorber with the first packaging body to obtain the elastic heat absorber frame.

[0009] Optionally, the mass fraction of glucomannan in the dispersion suspension in step S1 is 2%-20%; When the crosslinking agent is an oxide of a divalent metal, the mass ratio of the crosslinking agent to the glucomannan is (3-10):1, and the mass fraction of the crosslinking agent in the crosslinking agent suspension is 2%-20%. When the crosslinking agent is a basic carbonate of a divalent metal, the mass ratio of the crosslinking agent to the glucomannan is (4-10):1, and the mass fraction of the crosslinking agent in the crosslinking agent suspension is 4%-20%.

[0010] Optionally, the divalent metal includes one or more of Mg, Zn, Ca, Sr, Ba, Cu, and Mn.

[0011] Optionally, the heating temperature in steps S2 and S3 is 50-100℃.

[0012] Optionally, there are several mounting ports and several rigid heat insulation plates. The rigid heat insulation plates are arranged in a one-to-one correspondence with the mounting ports, and the elastic heat absorption frame is embedded in the four edges of each rigid heat insulation plate.

[0013] Optionally, the total projected area A2 of the rigid heat insulation board accounts for 50%-85% of the projected area A1 of the heat-absorbing and heat-insulating composite pad, and the total projected area A3 of the elastic heat-absorbing frame accounts for 15%-50% of the projected area A1 of the heat-absorbing and heat-insulating composite pad.

[0014] Optionally, the thickness of the elastic heat-absorbing frame is 1.2-3 times the thickness of the rigid heat insulation board.

[0015] Optionally, the rigid insulation board is any one of aerogel board, nano-insulation board, porous ceramic board, mica board, and aluminosilicate ceramic fiber board.

[0016] The present invention also proposes a battery module, comprising any of the above-described heat-absorbing and heat-insulating composite pads and at least two battery cells, wherein a heat-absorbing and heat-insulating composite pad is provided between two adjacent battery cells.

[0017] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: 1. In this invention, the elastic heat-absorbing frame includes a foam body and a heat-absorbing body. The heat-absorbing body is filled in several through holes and several closed holes, and the surface of the foam body is covered with the heat-absorbing body. The heat-absorbing body is a cross-linked hydrogel material. When the thermal runaway battery cell releases a large amount of heat, the water inside the heat-absorbing body absorbs the heat and vaporizes to produce water vapor. Moreover, the skeleton of the heat-absorbing body can further absorb heat and decompose. The heat-absorbing body plays a heat-absorbing role and can quickly, efficiently and in large quantities absorb the heat released by the thermal runaway battery cell, so that the elastic heat-absorbing frame has the effect of heat absorption and temperature reduction. Meanwhile, by placing the elastic heat-absorbing frame around the rigid heat insulation plate, the two are placed side by side on a horizontal plane. The generated water vapor can be directly released to the outside. That is, the present invention can directly discharge gas to the external environment while carrying away heat. The transfer and diffusion of heat are not hindered by the rigid heat insulation plate. Therefore, the present invention can absorb and dissipate heat quickly and efficiently, effectively reduce the surface temperature of the thermal runaway cell, play a role in inhibiting the spread of heat diffusion, and prevent adjacent cells from successively experiencing thermal runaway. At the same time, it has fireproof and flame-retardant effects, improves the safety of the entire battery module, and avoids safety accidents.

[0018] 2. The foam body of this invention has a porous structure, and its own skeleton has compressibility and elasticity. When the foam body is subjected to the expansion and compression force of the battery cell, the foam body absorbs the pressure through its own compression deformation. Therefore, it plays a role in adapting to the volume expansion changes of the battery cell and buffering stress during the charging and discharging process. Moreover, the foam body can also play a role in shock absorption and impact resistance during subsequent use or transportation. The foam body adopts a hydrophilic foam setting, and combined with the setting of the heat absorber being a cross-linked hydrogel material, it is beneficial for the heat absorber to be stably adsorbed inside or on the surface of the foam body, further ensuring the filling inside the foam body or the coating on the surface. The foam contains more heat absorbers; in addition, the porous structure of the foam itself gives it excellent heat insulation properties. When the heat absorbers are fully vaporized and decomposed, the heat transferred to the foam directly acts on the through-holes inside the foam. These through-holes increase thermal resistance by extending the heat conduction path and the low thermal conductivity of the gas, thus blocking heat transfer and playing a role in heat insulation. Furthermore, through-holes have the advantage of high load capacity compared to closed-holes, and more heat absorbers can be filled in the through-holes. Therefore, by combining several through-holes and several closed-holes, the interior of the foam can be filled with more heat absorbers, ultimately achieving the goal of absorbing more heat.

[0019] 3. The elastic heat-absorbing frame of this invention is thicker than the rigid heat insulation plate. The compressive force generated by the volume expansion of the battery cell under normal operating conditions acts on the elastic frame, which can resist the expansion compressive force generated during thermal runaway of the battery cell through its own elastic deformation, thus providing stress relief. Simultaneously, the thickness difference between the elastic heat-absorbing frame and the rigid heat insulation plate provides space for battery cell expansion. This invention, combining foam and rigid heat insulation plate, effectively buffers the expansion stress of the battery cell, preventing structural damage to adjacent cells due to expansion stress. Furthermore, the rigid heat insulation plate, with its low thermal conductivity, provides flame retardancy and heat insulation, effectively suppressing heat diffusion and further reducing the risk of thermal runaway in adjacent cells, thus meeting the flame retardancy and heat insulation requirements of the battery module in the event of battery cell thermal runaway. Therefore, this invention can quickly and efficiently absorb and dissipate heat, effectively reducing the surface temperature of the thermal runaway cell, inhibiting the spread of heat diffusion, preventing adjacent cells from experiencing thermal runaway, and effectively buffering the expansion stress of the cell, preventing structural damage to adjacent cells due to expansion stress, reducing the risk of thermal runaway in adjacent cells, thereby improving the safety of the entire battery module and preventing safety accidents. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a heat-absorbing and heat-insulating composite pad according to an embodiment of the present invention; Figure 2 This is a cross-sectional view of the elastic heat-absorbing frame of a heat-absorbing and heat-insulating composite pad according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the structure of a heat-absorbing and heat-insulating composite pad according to another embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a heat-absorbing and heat-insulating composite pad according to another embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of a battery module according to an embodiment of the present invention; Figure 6 This is a schematic diagram of a thermal runaway experiment conducted on a battery module according to an embodiment of the present invention. Figure 7 This is a thermocouple temperature curve diagram of Embodiment 1 of the present invention; Figure 8 This is a thermocouple temperature curve diagram for Comparative Example 1 of the present invention.

[0021] In the attached diagram: 1. Elastic heat-absorbing frame; 11. Foam body; 111. Through hole; 112. Closed hole; 12. Heat absorber; 13. First packaging body; 2. Rigid heat insulation plate; 3. Heat-absorbing and heat-insulating composite pad; 4. Battery module; 5. Battery cell; 51. Thermal runaway battery cell; 52. Adjacent battery cell; 53. Electrode of overcharge-induced thermal runaway battery cell; 6. Thermocouple. Detailed Implementation

[0022] This invention proposes a heat-absorbing and heat-insulating composite pad 3.

[0023] In embodiments of the present invention, such as Figure 1 and 2 As shown, the heat-absorbing and heat-insulating composite pad 3 includes an elastic heat-absorbing frame 1 and at least one rigid heat-insulating plate 2. The elastic heat-absorbing frame 1 is provided with an installation opening, and the rigid heat-insulating plate 2 is provided inside the installation opening. The four edges of the rigid heat-insulating plate 2 are all fixed inside the installation opening. The elastic heat-absorbing frame 1 includes a foam body 11 and a heat absorber 12. The foam body 11 is made of hydrophilic foam. The foam body 11 has several through holes 111, and several adjacent through holes 111 are interconnected. The foam body 11 also has several closed holes 112 inside. The several through holes 111 and several closed holes 112 are filled with heat absorber 12, and the surface of the foam body 11 is covered with heat absorber 12. The heat absorber 12 is a cross-linked hydrogel material. The rigid heat insulation board 2 is a rigid heat insulation material. The rigid heat insulation board 2 is used to provide the battery cell 5 with the functions of maintaining thickness, blocking heat and rigid protection, and the thickness of the elastic heat absorption frame 1 is greater than the thickness of the rigid heat insulation board 2.

[0024] In this invention, the elastic heat-absorbing frame 1 includes a foam body 11 and a heat-absorbing body 12. The heat-absorbing body 12 is filled in several through holes 111 and several closed holes 112, and the surface of the foam body 11 is covered with the heat-absorbing body 12. The heat-absorbing body 12 is a cross-linked hydrogel material. When the thermal runaway battery cell 51 releases a large amount of heat, the water inside the heat-absorbing body 12 absorbs the heat and vaporizes to produce water vapor. Moreover, the skeleton of the heat-absorbing body 12 can further absorb heat and decompose. The heat-absorbing body 12 plays a role in heat absorption and can quickly, efficiently and in large quantities absorb the heat released by the thermal runaway battery cell 51, so that the elastic heat-absorbing frame 1 has the effect of heat absorption and temperature reduction. Meanwhile, by placing the elastic heat-absorbing frame 1 around the rigid heat insulation plate 2, the two are placed side by side on a horizontal plane, and the generated water vapor can be directly released to the outside. That is, the present invention can directly discharge gas to the external environment while carrying away heat. The transfer and diffusion of heat are not hindered by the rigid heat insulation plate 2. Therefore, the present invention can absorb and dissipate heat quickly and efficiently, effectively reduce the surface temperature of the thermal runaway cell 51, play a role in inhibiting the spread of heat diffusion, and prevent adjacent cells 52 from successively experiencing thermal runaway. At the same time, it has fireproof and flame-retardant effects, improves the safety of the entire battery module 4, and avoids safety accidents.

[0025] The foam body 11 of this invention has a porous structure, and its own skeleton has compressibility and elasticity. When the foam body 11 is subjected to the expansion and compression force of the battery cell 5, the foam body 11 absorbs the pressure through its own compression deformation. Therefore, during the charging and discharging process of the battery cell 5, it plays a role in adapting to the volume expansion changes of the battery cell 5 and buffering stress. Moreover, during subsequent use or transportation, the foam body 11 can also play a role in shock absorption and impact resistance. The foam body 11 adopts a hydrophilic foam setting, and combined with the setting of the heat absorber 12 being a cross-linked hydrogel material, it is beneficial for the heat absorber 12 to be stably adsorbed inside or on the surface of the foam body 11, further ensuring that the interior of the foam body 11 is filled or the surface is covered with more heat absorbers 1. 2; In addition, the porous structure of the foam body 11 itself gives it a good heat insulation effect. When the heat absorber 12 is fully vaporized and decomposed, the heat transferred to the foam body 11 will directly act on the through holes 111 inside the foam body 11. These through holes 111 increase the thermal resistance by extending the heat conduction path and the low thermal conductivity of the gas, thus blocking the heat transfer and playing a heat insulation role. In addition, the through holes 111 have the advantage of high load capacity compared with the closed holes 112. More heat absorbers 12 can be filled in the through holes 111. Therefore, by combining several through holes 111 and several closed holes 112, more heat absorbers 12 can be filled inside the foam body 11, ultimately achieving the purpose of absorbing more heat.

[0026] The elastic heat-absorbing frame 1 of this invention has a thickness greater than that of the rigid heat insulation plate 2. The compressive force generated by the volume expansion of the battery cell 5 under normal operating conditions acts on the elastic frame, which can resist the expansion compressive force generated by the battery cell 5 under thermal runaway conditions through its own elastic deformation, thus providing stress relief. Simultaneously, the thickness difference between the elastic heat-absorbing frame 1 and the rigid heat insulation plate 2 provides reserved space for the expansion of the battery cell 5. This invention, combining the foam body 11 and the rigid heat insulation plate 2, can effectively buffer the expansion stress of the battery cell 5, preventing structural damage to adjacent battery cells 52 due to expansion stress. Furthermore, combined with its low thermal conductivity, the rigid heat insulation plate 2 has flame-retardant and heat-insulating properties, effectively suppressing heat diffusion and further reducing the risk of thermal runaway in adjacent battery cells 52, thus meeting the flame-retardant and heat-insulating requirements of the battery module 4 in the event of thermal runaway of the battery cell 5. Therefore, the present invention can absorb and dissipate heat quickly and efficiently, effectively reducing the surface temperature of the thermal runaway cell 51, suppressing the spread of heat diffusion, preventing adjacent cells 52 from experiencing thermal runaway one after another, and effectively buffering the expansion stress of the cell 5, preventing adjacent cells 52 from being structurally damaged due to expansion stress, reducing the risk of thermal runaway of adjacent cells 52, thereby improving the safety of the entire battery module 4 and preventing safety accidents.

[0027] This invention solves the problems of existing heat insulation pads being unable to absorb and dissipate heat quickly and efficiently, unable to reduce the surface temperature of thermally runaway battery cells, and unable to effectively buffer the expansion stress of battery cells, increasing the risk of thermal runaway in adjacent battery cells, affecting the safety of the entire battery module, and even causing safety accidents.

[0028] To further explain, the principle of filling the through-holes 111 and closed-holes 112 of the foam body 11 with the heat absorber 12 is as follows: the foam body 11 is a porous material and uses hydrophilic foam, and the heat absorber 12 is a cross-linked hydrogel material. Before the cross-linked hydrogel material undergoes cross-linking and curing, the cross-linked hydrogel material can be penetrated into the through-holes 111 of the foam body 11 by soaking. At the same time, it can also diffuse to the wall of the closed-holes 112 and finally penetrate into the closed-holes 112, so as to achieve a full combination of the heat absorber 12 and the foam body 11.

[0029] In one embodiment of this application, the heat absorber 12 is a glucomannan hydrogel; the elastic heat-absorbing frame 1 also includes a first packaging body 13, which is a thermoplastic film material and completely wraps the foam body 11. The first packaging body 13 is used to seal and protect the foam body 11. The preparation method of the elastic heat-absorbing frame 1 includes the following steps: Step S1: Prepare a dispersion suspension by mixing glucomannan and water evenly; prepare a crosslinking agent suspension by mixing crosslinking agent and water evenly. The crosslinking agent is selected from oxides of divalent metals or basic carbonates of divalent metals; Step S2: After heating the dispersion suspension, add the crosslinking agent suspension, maintain the temperature and stir evenly to prepare glucomannan aqueous slurry; Step S3: Maintain the temperature of step S2, immerse the foam body 11 in the glucomannan aqueous slurry while it is still hot, and cool it to room temperature to obtain a mixture, which includes the foam body 11 and the heat absorber 12. Step S4: The mixture is cured at room temperature for more than 24 hours to obtain an elastic cross-linked heat absorber; Step S5: Cut the cross-linked heat absorber according to the preset size and position to form an installation opening, and then use the first packaging body 13 to seal the cut cross-linked heat absorber to obtain the elastic heat absorber frame 1.

[0030] The heat absorber 12 is a glucomannan hydrogel. During the preparation of the elastic heat-absorbing frame 1, the aqueous glucomannan slurry can effectively penetrate into the through-pores 111 and closed-pores 112 of the foam body 11 and cover the surface of the foam body 11. After cooling, it forms a glucomannan hydrogel, resulting in a mixture. The glucomannan hydrogel has the advantage of high specific heat capacity. When the thermal runaway battery cell 51 releases a large amount of heat, the heat absorber 12 can efficiently and massively absorb the heat. The water inside the heat absorber 12 vaporizes, producing water vapor. Due to the use of thermoplastic film material in the first packaging body 13, the first packaging body 13 can melt and rupture at high temperatures, creating a rupture opening. This allows the water vapor to escape from the rupture opening, ultimately achieving heat absorption and dissipation. Furthermore, by placing the first packaging body 13 around the rigid heat insulation plate 2, the first packaging body 13 and the rigid heat insulation plate 2 are placed side by side on a horizontal plane. When the thermal runaway cell 51 releases heat, the first packaging body 13 melts and ruptures around the rigid heat insulation plate 2. This makes it easier to open the first packaging body 13, directly expelling gas to the external environment while carrying away heat. This invention combines heat absorption and heat dissipation to effectively reduce the surface temperature of the thermal runaway cell 51, maintaining its temperature within a stable range. This not only prevents adjacent cells 52 from experiencing thermal runaway successively but also reduces temperature unevenness caused by local overheating, thereby balancing the temperature difference of the entire battery module.

[0031] The first packaging body 13 protects and isolates the heat absorber 12, preventing moisture evaporation and drying of the heat absorber 12 during normal use of the lithium battery. Without the first packaging body 13, the function of the heat absorber 12 may decrease, making it difficult to absorb heat during thermal runaway of the battery cell 5, potentially leading to successive thermal runaway of adjacent battery cells 52. Therefore, the first packaging body 13 effectively seals and protects the foam body 11, thereby ensuring that the elastic heat-absorbing frame 1 can effectively absorb heat.

[0032] In step S1, the crosslinking agent is selected from divalent metal oxides or divalent metal basic carbonates. Divalent metal oxides and divalent metal basic carbonates have low solubility in water. When the crosslinking agent is stirred evenly with water, the divalent metal oxides and divalent metal basic carbonates slowly diffuse and dissolve in water. At this time, the alkalinity of the crosslinking agent suspension is relatively weak, so the crosslinking and curing process of glucomannan (the crosslinking reaction of glucomannan under the action of the crosslinking agent) is slow, the gelation speed of glucomannan is appropriate, and the glucomannan molecules will not quickly form a tight three-dimensional network. That is, the glucomannan aqueous slurry will not form glucomannan hydrogel too early. This is beneficial for the soaking operation in step S3, which allows the glucomannan aqueous slurry to fully penetrate into the through holes 111 and closed holes 112 of the foam body 11, and at the same time, it fully covers the surface of the foam body 11, further improving the heat absorption effect of the elastic heat-absorbing frame 1. If a strong base of a monovalent metal is used as the crosslinking agent, the alkalinity of the crosslinking agent suspension is relatively strong, the crosslinking reaction rate of glucomannan is too fast, and the aqueous glucomannan slurry quickly forms a glucomannan hydrogel, which cannot penetrate into the foam body 11. This results in a reduction in the heat absorption effect of the elastic heat-absorbing frame 1, and when the battery cell 5 experiences thermal runaway, it cannot reduce the surface temperature of the thermal runaway battery cell 51, nor can it suppress the spread of heat diffusion.

[0033] Preferably, the foam body 11 is made of hydrophilic polyurethane foam or melamine foam.

[0034] To further illustrate, in the embodiments of the present invention, the foam body 11 is selected from polyurethane sponge or melamine sponge with a porosity of 50%-95%.

[0035] Preferably, the first packaging body 13 is an aluminum-plastic film or a plastic sealed bag.

[0036] Specifically, when the first packaging body 13 is a plastic sealed bag, the cut cross-linked heat absorber is placed into the plastic sealed bag and then vacuum sealed.

[0037] To further clarify, the water temperature in step S1 is 20℃-25℃. Preferably, the water temperature in step S1 is 25℃.

[0038] To further explain, the soaking time in step S3 is 5-60 seconds. In embodiments of the present invention, the preferred soaking time is 5-10 seconds.

[0039] In one embodiment of this application, the mass fraction of glucomannan in the dispersion suspension of step S1 is 2%-20%; When a divalent metal oxide is selected as the crosslinking agent, the mass ratio of the crosslinking agent to glucomannan is (3-10):1, and the mass fraction of the crosslinking agent in the crosslinking agent suspension is 2%-20%. When the crosslinking agent is a basic carbonate of a divalent metal, the mass ratio of the crosslinking agent to glucomannan is (4-10):1, and the mass fraction of the crosslinking agent in the crosslinking agent suspension is 4%-20%.

[0040] Oxides of divalent metals react directly with water, and the resulting hydroxides, although having low solubility, quickly dissolve divalent metal ions. These ions can rapidly crosslink with glucomannan, resulting in a fast crosslinking reaction. In contrast, basic carbonates of divalent metals require a longer time to release sufficient free divalent metal ions when placed in water, thus failing to rapidly supply metal ions and slowing the crosslinking reaction. Consequently, the crosslinking and curing process of glucomannan is slow, and the crosslinking efficiency of basic carbonates of divalent metals is lower than that of divalent metal oxides. Based on the above, this invention controls the mass fraction of glucomannan in the dispersion suspension, combines two crosslinking agents, and controls the mass ratio of crosslinking agents to glucomannan, as well as the mass fraction of crosslinking agents in the crosslinking agent suspension. When the dispersion suspension and the crosslinking agent suspension are stirred evenly, a glucomannan aqueous slurry with a water content of over 80%, suitable viscosity, and uniform crosslinking agent distribution can be obtained. This facilitates the full penetration of the glucomannan aqueous slurry into the interior of the foam body 11, thereby improving the heat absorption effect of the elastic heat-absorbing frame 1.

[0041] In one embodiment of this application, the divalent metal includes one or more of Mg, Zn, Ca, Sr, Ba, Cu, and Mn.

[0042] In this invention, the crosslinking agent is selected from oxides or basic carbonates of divalent metals. The divalent metals include one or more of Mg, Zn, Ca, Sr, Ba, Cu, and Mn. When these oxides or basic carbonates of divalent metals are dissolved in water, the divalent metal ions generated by the decomposition can undergo a mild crosslinking reaction with glucomannan, controlling the gelation rate of glucomannan and slowing down the crosslinking and solidification process of glucomannan. This facilitates the full penetration of the glucomannan aqueous slurry into the foam body 11 and its stable adsorption on the foam body 11, thereby ensuring that the prepared elastic heat-absorbing frame 1 has a high heat absorption effect.

[0043] In one embodiment of this application, the heating temperature in steps S2 and S3 is 50-100°C.

[0044] Compared to using a strong base of a monovalent metal as a crosslinking agent, the two crosslinking agents selected in this invention (oxides of divalent metals or basic carbonates of divalent metals) have low solubility in water, and the crosslinking and curing process of glucomannan is relatively slow. By controlling the heating temperature of steps S2 and S3, the crosslinking reaction of glucomannan can be promoted, and the gelation speed of glucomannan can be appropriately increased. In this way, there is no need to prolong the soaking time of the foam body 11 in the aqueous glucomannan slurry, which improves the production efficiency of the elastic heat-absorbing frame 1.

[0045] like Figure 3 and 4 As shown, in one embodiment of this application, there are several installation ports and several rigid heat insulation plates 2. The rigid heat insulation plates 2 are arranged in a one-to-one correspondence with the installation ports, and each rigid heat insulation plate 2 has an elastic heat absorption frame 1 embedded in its four edges.

[0046] The rigid heat insulation plate 2 has elastic heat-absorbing frames 1 embedded in all four edges, and the rigid heat insulation plate 2 is fixedly connected to the elastic heat-absorbing frame 1 by inlaying. By setting several mounting holes and configuring the rigid heat insulation plate 2 at each mounting hole, the present invention makes the shape of the elastic heat-absorbing frame 1 more diverse. This also means that the elastic heat-absorbing frame 1 is not only set for the outer ring position of the battery cell 5, but can adapt to different areas of the battery cell 5, thereby absorbing heat from multiple positions on the surface of the battery cell 5, further improving the heat absorption and heat dissipation effect, and effectively reducing the surface temperature of the thermal runaway battery cell 51. At this time, the foam body 11 of the elastic heat-absorbing frame 1 has a better buffering stress effect.

[0047] Preferably, the heat-absorbing and heat-insulating composite pad 3, the rigid heat insulation plate 2, and the mounting opening of the present invention are all rectangular.

[0048] like Figure 3 As shown, in one embodiment of the present invention, two mounting ports are provided, and two rigid heat insulation plates 2 are provided accordingly. At this time, the two rigid heat insulation plates 2 can respectively correspond to two areas of the battery cell 5. Compared with only one rigid heat insulation plate 2, it can absorb the heat of different areas of the thermal runaway battery cell 51, thereby effectively reducing its surface temperature.

[0049] like Figure 4 As shown, in another embodiment of the present invention, four mounting ports are provided, and four rigid heat insulation plates 2 are provided accordingly. At this time, the four rigid heat insulation plates 2 can respectively correspond to the four areas of the battery cell 5, and the elastic heat absorption frame 1 can adapt to multiple areas of the battery cell 5, quickly and efficiently absorbing the heat of the thermal runaway battery cell 51.

[0050] In one embodiment of this application, the total projected area A2 of the rigid heat insulation board 2 accounts for 50%-85% of the projected area A1 of the heat-absorbing and heat-insulating composite pad 3, and the total projected area A3 of the elastic heat-absorbing frame 1 accounts for 15%-50% of the projected area A1 of the heat-absorbing and heat-insulating composite pad 3.

[0051] In this invention, the total projected area A3 of the elastic heat-absorbing frame 1 accounts for 15%-50% of the projected area A1 of the heat-absorbing and heat-insulating composite pad 3. If the total projected area A3 of the elastic heat-absorbing frame 1 is greater than 50%, then when the heat absorber 12 absorbs the heat from the thermally runaway battery cell 51 and fully vaporizes and decomposes, there will be no more heat absorber 12 inside the through holes 111 and closed holes 112 of the foam body 11, and the heat insulation effect of the foam body 11 will be limited. At this time, the total projected area A2 of the rigid heat insulation plate 2 is less than 50%. The area ratio of the rigid heat insulation plate 2 is too small, which means that the heat insulation area is too small. Under the condition that the thermally runaway battery cell 51 continues to release heat, it will eventually lead to thermal runaway of the adjacent battery cell 52. Therefore, by controlling the proportion of the total projected area A2 of the rigid heat insulation plate 2 and the proportion of the total projected area A3 of the elastic heat-absorbing frame 1, this invention can ensure that the heat-absorbing and heat-insulating heat dissipation pad can stably and fully exert its heat absorption and heat insulation effects.

[0052] In one embodiment of this application, the thickness of the elastic heat-absorbing frame 1 is 1.2-3 times the thickness of the rigid heat insulation plate 2.

[0053] In this invention, the thickness of the elastic heat-absorbing frame 1 is greater than the thickness of the rigid heat insulation board 2, and the foam body 11 skeleton itself is compressible with a large compression ratio. When the battery cell 5 expands in volume during charging and discharging, the battery cell 5 will first compress the foam body 11. At this time, the foam body 11 absorbs the pressure through its own compression deformation, thereby playing a role in buffering stress. If the thickness of the elastic heat-absorbing frame 1 is less than 1.2 times the thickness of the rigid heat insulation board 2, the stress buffering effect of the foam body 11 is not good. However, if the thickness of the elastic heat-absorbing frame 1 is more than 3 times the thickness of the rigid heat insulation board 2, the thickness of the elastic heat-absorbing frame 1 is too large and the thickness of the rigid heat insulation board 2 is too small. The rigid heat insulation board 2 is prone to loosening. Moreover, when this invention is installed between two battery cells 5, the foam body 11 will generate a large amount of compression. If the compression ratio is too large, the foam body 11 cannot play a role in buffering stress and will also cause mechanical damage to the battery cell 5.

[0054] In one embodiment of this application, the rigid insulation board 2 is any one of aerogel board, nano-insulation board, porous ceramic board, mica board and aluminum silicate ceramic fiber board.

[0055] The rigid heat insulation board 2 is any one of aerogel board, nano heat insulation board, porous ceramic board, mica board and aluminum silicate ceramic fiber board. The rigid heat insulation board 2 has good heat insulation performance and mechanical strength, flame retardant and heat insulation functions, and can also resist the expansion and extrusion force generated by the thermal runaway state of the battery cell 5, providing rigid protection for the adjacent battery cell 52.

[0056] In one embodiment of the present invention, when the rigid heat insulation board 2 is selected as a ceramic fiber aerogel board, the rigid heat insulation board 2 includes aerogel and a second packaging body. The second packaging body completely covers the aerogel and is used to seal and protect the aerogel to prevent damage to the aerogel under external force. More specifically, the second packaging body is a PET film.

[0057] The present invention also proposes a battery module 4, such as Figure 5 As shown, the battery module 4 includes any of the above-mentioned heat-absorbing and heat-insulating composite pads 3 and at least two battery cells 5, with a heat-absorbing and heat-insulating composite pad 3 provided between two adjacent battery cells 5.

[0058] This battery module 4 includes a heat-absorbing and heat-insulating composite pad 3. The heat-absorbing and heat-insulating composite pad 3 can quickly and efficiently absorb and dissipate heat, effectively reducing the surface temperature of the thermal runaway cell 51, inhibiting the spread of heat diffusion, preventing adjacent cells 5 from successively experiencing thermal runaway, and effectively buffering the expansion stress of the cell 5, preventing structural damage to adjacent cells 5 due to expansion stress, reducing the risk of thermal runaway in adjacent cells 5, thereby improving the safety of the entire battery module 4 and preventing safety accidents. Therefore, this battery module 4 has high safety and can effectively prevent safety accidents.

[0059] In one embodiment of the present invention, the battery module 4 further includes insulating adhesive, and the heat-absorbing and heat-insulating composite pad 3 is connected to the battery cell 5 through the insulating adhesive.

[0060] Specifically, the insulating adhesive is an insulating double-sided adhesive. The present invention is fixed between two battery cells 5 using the insulating double-sided adhesive. Specifically, the insulating double-sided adhesive is used to apply adhesive to the back of the elastic heat-absorbing frame 1 and the rigid heat-insulating plate 2 respectively, so as to attach the present invention between the two battery cells 5 (such as lithium battery cells).

[0061] To facilitate understanding of the present invention, a more complete description is provided below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0062] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0063] Example 1 A heat-absorbing and heat-insulating composite pad 3 includes an elastic heat-absorbing frame 1 and a rigid heat-insulating plate 2 (4 rigid heat-insulating plates 2 are provided). The elastic heat-absorbing frame 1 is provided with an installation opening (4 installation openings are provided). The rigid heat-insulating plate 2 is provided in the installation opening, and the four edges of the rigid heat-insulating plate 2 are all fixed in the installation opening. The elastic heat-absorbing frame 1 includes a foam body 11 and a heat absorber 12. The foam body 11 is made of hydrophilic foam (the foam body 11 is made of hydrophilic polyurethane sponge with a porosity of 90%). The foam body 11 has several through holes 111, and several adjacent through holes 111 are interconnected. The foam body 11 also has several closed pores 112 inside. The several through holes 111 and several closed pores 112 are filled with heat absorbers 12, and the surface of the foam body 11 is covered with heat absorbers 12. The heat absorber 12 is a cross-linked hydrogel material (the heat absorber 12 is glucomannan hydrogel). The rigid heat insulation board 2 is a rigid heat insulation material (the rigid heat insulation board 2 is a ceramic fiber aerogel board, the rigid heat insulation board 2 includes aerogel and a second packaging body, the second packaging body is a PET film). The rigid heat insulation board 2 is used to provide the battery cell 5 with the functions of maintaining thickness, blocking heat and rigid protection, and the thickness of the elastic heat absorption frame 1 is greater than the thickness of the inductive heat insulation board 2. The elastic heat-absorbing frame 1 also includes a first packaging body 13 (the first packaging body 13 is a plastic sealed bag), and the preparation method of the elastic heat-absorbing frame 1 includes the following steps: Step S1: Prepare a dispersion suspension by mixing 80g glucomannan powder with 1000g water (water temperature is 25℃) until homogeneous; prepare a crosslinking agent suspension by mixing 240g magnesium oxide powder with 1000g water (water temperature is 25℃) until homogeneous. Step S2: After heating the dispersion suspension to 80°C, add the crosslinking agent suspension, maintain the temperature (80°C) and stir evenly to prepare the glucomannan aqueous slurry; Step S3: Maintain the temperature of step S2, and soak the foam body 11 in the glucomannan aqueous slurry while it is still hot (soaking time is 10 seconds). After cooling to room temperature, a mixture is obtained, which includes the foam body 11 and the heat absorber 12. Step S4: The mixture is cured at room temperature for more than 24 hours to obtain an elastic cross-linked heat absorber; Step S5: Cut the cross-linked heat absorber according to the preset size and position to form an installation opening. Then, use the first packaging body 13 to seal the cut cross-linked heat absorber (the specific steps are to put the cut cross-linked heat absorber into a plastic sealing bag and then vacuum seal it) to obtain the elastic heat absorber frame 1.

[0064] The heat-absorbing and heat-insulating composite pad 3 has a length and width of 205mm*172mm, the rigid heat insulation board 2 has a length and width of 90mm*75mm, the total projected area A2 of the rigid heat insulation board 2 accounts for 76.6% of the projected area A1 of the heat-absorbing and heat-insulating composite pad 3, and the total projected area A3 of the elastic heat-absorbing frame 1 accounts for 23.4% of the projected area A1 of the heat-absorbing and heat-insulating composite pad 3. The elastic heat-absorbing frame 1 has a thickness of 2.5 mm, the rigid heat insulation board 2 has a thickness of 1 mm, and the thickness of the elastic heat-absorbing frame 1 is 2.5 times the thickness of the rigid heat insulation board 2.

[0065] The heat-absorbing and heat-insulating composite pad 3 of Example 1 is assembled with the battery cell 5 (lithium-ion battery cell) to form a battery module 4. The battery module 4 includes 5 battery cells 5, and a heat-absorbing and heat-insulating composite pad 3 is provided between two adjacent battery cells 5 (the heat-absorbing and heat-insulating composite pad 3 is attached between two adjacent battery cells 5 using double-sided adhesive).

[0066] Examples 2-9 The difference between Examples 2-9 and Example 1 lies in the different preparation parameters of steps S1 and S2 (i.e., the different glucomannan aqueous slurries prepared). Specifically, the mass of glucomannan in step S1, the mass of water used to prepare the dispersion suspension, the mass of the crosslinking agent and its mass, the mass of water used to prepare the crosslinking agent suspension, and the heating temperature in step S2 are different, as shown in Table 1.

[0067] Table 1 Comparison of preparation parameters for steps S1 and S2 in Examples 1-9 .

[0068] Examples 10-14 The difference between Examples 10-14 and Example 1 lies in the parameters and types of the rigid heat insulation board 2 and the elastic heat absorption frame 1. This includes the number, length, width, thickness, and type of the rigid heat insulation board 2, as shown in Table 2. It also includes the thickness of the elastic heat absorption frame 1, the type of foam body 11, and the glucomannan water-based slurry, as shown in Table 3.

[0069] Table 2 Comparison of parameters and types of rigid insulation boards in Examples 1 and 10-14 .

[0070] Table 3 Comparison of parameters and types of elastic heat-absorbing frames in Examples 1 and 10-14 .

[0071] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that a rigid heat insulation board 2 (a ceramic fiber aerogel board) is used instead of the heat-absorbing and heat-insulating composite pad 3. The elastic heat-absorbing frame 1 is not used in this comparative example. The number, length, width, thickness and type of the rigid heat insulation board 2 are shown in Table 4.

[0072] The ceramic fiber aerogel plate is assembled with the battery cell 5 (lithium-ion battery cell 5) to form a battery module. In this comparative example, the battery module includes 5 battery cells 5, and a ceramic fiber aerogel plate is provided between two adjacent battery cells 5 (the ceramic fiber aerogel plate is attached between two adjacent battery cells 5 using insulating double-sided tape).

[0073] Comparative Example 2 The difference between Comparative Example 2 and Example 10 is that the width of the rigid heat insulation board 2 and the glucomannan water-based slurry are different. The specific parameters and types of the rigid heat insulation board 2 are shown in Table 4, and the parameters and types of the elastic heat absorption frame 1 are shown in Table 5.

[0074] Table 4 Comparison of parameters and types of rigid insulation boards in Example 1 and Comparative Examples 1-2 .

[0075] Table 5 Comparison of parameters and types of elastic heat-absorbing frames in Example 1 and Comparative Examples 1-2 .

[0076] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that in step S1, 200g of sodium hydroxide and 100g of water (the temperature of the water is 25°C) are stirred evenly to prepare a crosslinking agent suspension.

[0077] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that the thickness of the elastic heat-absorbing frame 1 is 7 mm, the thickness of the rigid heat-absorbing plate is 1 mm, and the thickness of the elastic heat-absorbing frame 1 is 7 times the thickness of the rigid heat-insulating plate 2.

[0078] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that the foam body 11 is made of hydrophilic polyurethane sponge with a porosity of 45%.

[0079] Thermal runaway experiments were conducted on the battery modules composed of Example 1 and Comparative Example 1. The specific steps of the thermal runaway experiment are as follows: thermal runaway was induced in the intermediate cell 5 using an overcharge method, such as... Figure 6As shown, the middle cell 5 is the thermal runaway cell 51, and the other four cells 5 are adjacent cells 52. A thermocouple 6 is placed between the middle cell 5 and one of the heat-absorbing and heat-insulating composite pads 3. The temperature of the thermocouple 6 represents the surface temperature of the middle cell 5. The surface of the middle cell 5 is provided with an electrode, which is the electrode 53 of the overcharge-induced thermal runaway cell. During the experiment, (1) the highest surface temperature of the middle cell 5 is recorded; (2) it is determined whether a cooling valley occurs and the duration of the cooling valley; (3) the time required for the thermal runaway to end when the surface temperature of the middle cell 5 drops to 150°C is taken as the end point; and (4) it is checked whether the safety valves of the two adjacent cells 52 of the middle cell 5 are open. To further explain, the surface of the existing cell 5 is usually provided with electrodes and safety valves. The safety valve is a low-voltage switch installed on cell 5 by the cell manufacturer. When cell 5 experiences thermal runaway and the internal pressure exceeds the pressure the safety valve can withstand, the safety valve will open, releasing the vaporized electrolyte inside the thermally runaway cell 51. The temperature at which the safety valve opens is related to the design of cell 5.

[0080] After the thermal runaway experiment is completed, a thermocouple temperature curve will be obtained.

[0081] Thermocouple temperature curve of Example 1 is shown below. Figure 7 As shown, from Figure 7 It can be seen that after the intermediate battery cell 5 experienced thermal runaway, its temperature rose sharply, reaching a maximum of 361°C, before rapidly decreasing to 248°C. The cooling process lasted approximately 7 minutes. The temperature then rose to 331°C before slowly cooling down. A cooling trough occurred between the maximum temperature of 361°C and 331°C. This is because the intermediate battery cell 5 released a large amount of heat, causing the first packaging body 13 of the elastic heat-absorbing frame 1 to melt and rupture, creating a rupture. The heat absorber 12 absorbed the heat and vaporized, producing water vapor that escaped from the rupture. Simultaneously, the frame of the heat absorber 12 further absorbed heat and decomposed. The heat absorber 12 absorbed a large amount of heat released by the intermediate battery cell 5, directly releasing gas into the environment while carrying away heat, thus cooling the intermediate battery cell 5 and effectively reducing its surface temperature. In Example 1, the time required to cool down to 150°C was 5753 seconds, and the safety valves of the two adjacent battery cells 52 did not open.

[0082] The thermocouple temperature curve of Comparative Example 1 is shown below. Figure 8 As shown, from Figure 8It can be seen that after the intermediate cell 5 experienced thermal runaway, its temperature rose sharply to 561°C, and then cooled down slowly without any cooling trough. The highest temperature of Comparative Example 1 was about 200°C higher than that of Example 1, and the time required for Comparative Example 1 to cool down to 150°C was 6816s (1063s longer than that required for Example 1), and the safety valves of both adjacent cells 52 opened. This is because Comparative Example 1 only used a rigid heat insulation plate 2 and did not use an elastic heat absorption frame 1. When the intermediate cell 5 released a large amount of heat, the rigid heat insulation plate 2 could only slow down the heat transfer rate and could not absorb or dissipate heat. Therefore, it would eventually induce thermal runaway in the two adjacent cells 52.

[0083] In Comparative Example 2, the total projected area A2 of the rigid heat insulation board 2 accounts for 45.9% of the projected area A1 of the heat-absorbing and heat-insulating composite pad 3. At this time, the total projected area A3 of the elastic heat-absorbing frame 1 accounts for 54.1%. The heat released by the intermediate battery cell 5 causes the heat absorber 12 of the elastic heat-absorbing frame 1 to fully vaporize and decompose. The through holes 111 and closed holes 112 of the foam body 11 no longer have heat absorbers 12. Although the foam body 11 has a good heat insulation effect due to its porous structure, the heat insulation effect of the foam body 11 is limited. Moreover, the area ratio of the rigid heat insulation board 2 is too small, which means that the heat insulation area is too small. Under the condition that the intermediate battery cell 5 continues to release heat, it will eventually lead to thermal runaway of the two adjacent battery cells 52.

[0084] In Comparative Example 3, sodium hydroxide (a strong base of monovalent metals) was selected as the crosslinking agent. After stirring evenly, the sodium hydroxide dissolved to obtain a clear and transparent crosslinking agent solution. The temperature rose to 72°C. At this time, the crosslinking agent solution was highly alkaline. When added to the dispersion suspension preheated to 80°C, the two reacted rapidly and formed a gel block, which was not conducive to the soaking of the foam body 11. At this time, the glucomannan aqueous slurry could not penetrate into the foam body 11, resulting in poor heat absorption effect of the elastic heat-absorbing frame 1. Therefore, when the battery cell 5 experienced thermal runaway, its surface temperature could not be reduced.

[0085] In Comparative Example 4, the thickness of the elastic heat-absorbing frame 1 is 7 times the thickness of the rigid heat insulation plate 2. Because the thickness of the elastic heat-absorbing frame 1 is too large, when it is used to assemble the battery cell module, the thickness of the elastic heat-absorbing frame 1 is also relatively large when the pre-tightening force is applied to compress the elastic heat-absorbing frame 1. This will cause the gap between it and the battery cell to be too large (4mm). The rigid heat insulation plate 2 will not be firmly fixed and will shake.

[0086] In Comparative Example 5, the porosity of the foam body 11 is 45%, which is too small. The number of through-holes 111 and closed-holes 112 in the foam body 11 is small. After soaking, the foam body 11 does not adsorb and load enough glucomannan aqueous slurry, resulting in less heat absorber 12 filling the inside of the foam body 11. This leads to insufficient heat absorption of the thermal runaway battery cell 51, and the heat absorption effect of the elastic heat-absorbing frame 1 is poor. When the battery cell 5 experiences thermal runaway, it cannot reduce its surface temperature and it is difficult to suppress the spread of thermal runaway of the battery cell 5. Ultimately, this will lead to thermal runaway of two adjacent battery cells 52.

[0087] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A heat absorbing and insulating composite pad, characterized by, The elastic heat-absorbing frame is provided with a mounting opening, and the rigid heat-insulating plate is arranged in the mounting opening and fixed around the mounting opening. The elastic heat-absorbing frame comprises a foam body and a heat-absorbing body, the foam body is made of hydrophilic foam, the foam body is provided with a plurality of through holes, and the through holes are communicated with each other, the foam body is further provided with a plurality of closed holes, the through holes and the closed holes are filled with the heat-absorbing body, and the surface of the foam body is covered with the heat-absorbing body, and the heat-absorbing body is a cross-linked hydrogel material. The rigid heat-insulating plate is made of rigid heat-insulating material, and is used for maintaining the thickness of the battery cell, blocking heat and providing rigid protection, and the thickness of the elastic heat-absorbing frame is greater than that of the rigid heat-insulating plate.

2. The thermally absorbing, thermally insulating composite blanket of claim 1, wherein, The heat-absorbing body is a glucosan hydrogel, the elastic heat-absorbing frame further comprises a first packaging body, the first packaging body is made of thermoplastic film material and completely wraps the foam body, and the first packaging body is used for sealing and protecting the foam body. The preparation method of the elastic heat-absorbing frame comprises the following steps: In step S1, a dispersion suspension is prepared by uniformly stirring glucosan and water, and a cross-linking agent suspension is prepared by uniformly stirring a cross-linking agent and water; The cross-linking agent is selected from oxides of divalent metals or basic carbonates of divalent metals; In step S2, the dispersion suspension is heated, the cross-linking agent suspension is added, and the temperature is maintained to uniformly stir to prepare a glucosan aqueous slurry; In step S3, the temperature of step S2 is maintained, the foam body is soaked in the glucosan aqueous slurry while hot, and a mixture is obtained after cooling to room temperature, the mixture comprises the foam body and the heat-absorbing body; In step S4, the mixture is cured at room temperature for more than 24 hours to obtain a cross-linked heat-absorbing body with elasticity; In step S5, the cross-linked heat-absorbing body is cut according to the predetermined size and position to form the mounting opening, and then the cross-linked heat-absorbing body after cutting is sealed by using the first packaging body to obtain the elastic heat-absorbing frame.

3. The radiant heat barrier and insulating composite pad of claim 2, wherein, In step S1, the mass fraction of glucosan in the dispersion suspension is 2%-20%; When the cross-linking agent is selected from oxides of divalent metals, the mass ratio of the cross-linking agent to the glucosan is (3-10):1, and the mass fraction of the cross-linking agent in the cross-linking agent suspension is 2%-20%; When the cross-linking agent is selected from basic carbonates of divalent metals, the mass ratio of the cross-linking agent to the glucosan is (4-10):1, and the mass fraction of the cross-linking agent in the cross-linking agent suspension is 4%-20%.

4. The radiant heat barrier and insulating composite mat of claim 2, wherein, The divalent metal comprises one or more of Mg, Zn, Ca, Sr, Ba, Cu and Mn.

5. The radiant heat barrier and insulating composite mat of claim 2, wherein, The heating temperature of step S2 and step S3 is 50-100℃.

6. The radiant heat barrier and insulating composite mat of claim 1, wherein, The mounting opening is provided with a plurality of mounting openings, the rigid heat-insulating plate is provided with a plurality of rigid heat-insulating plates, and the rigid heat-insulating plate is arranged in one-to-one correspondence with the mounting opening, and the four edges of each rigid heat-insulating plate are embedded in the elastic heat-absorbing frame.

7. The thermally absorptive, thermally insulative composite gasket of claim 6, wherein, The total orthographic projection area A2 of the rigid heat insulation plate accounts for 50%-85% of the orthographic projection area A1 of the heat-absorbing and heat-insulating composite pad, and the total orthographic projection area A3 of the elastic heat-absorbing frame accounts for 15%-50% of the orthographic projection area A1 of the heat-absorbing and heat-insulating composite pad.

8. The thermally absorptive, thermally insulative composite blanket of claim 1, wherein, The thickness of the elastic heat-absorbing frame is 1.2-3 times the thickness of the rigid heat insulation plate.

9. The thermally absorptive, thermally insulative composite gasket of claim 8, wherein, The rigid heat insulation plate is any one of an aerogel plate, a nano heat insulation plate, a porous ceramic plate, a mica plate and an aluminum silicate ceramic fiber plate.

10. A battery module, characterized by The heat-absorbing and heat-insulating composite pad as claimed in any one of claims 1 to 9 and at least two electric cores are included, and one heat-absorbing and heat-insulating composite pad is arranged between two adjacent electric cores.

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