Battery module heating structure and installation method therefor

Abstract

To provide a battery module heating structure and an installation method thereof that increase the structural stability of a battery module and absorb the effects of temperature differences between battery cells due to differences in placement position and working environment.SOLUTION: A battery module heating structure includes a case 1, a battery module, and a heating assembly 3. The case has a receiving groove 100, the battery module is installed in the receiving groove, and the heating assembly is installed between the bottom of the receiving groove and the battery module. The heating assembly has a first heating zone and a second heating zone for heating different zones of the battery module. The heating power of the first heating zone and the second heating zone is different.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the field of battery technology, and in particular to a heating structure for a battery module and a mounting method thereof. [Background technology]

[0002] A battery module is an entire unit made up of multiple individual batteries, and typically consists of multiple individual batteries, a battery management system (BMS), a battery protection circuit, connectors, and other components. The main function of a battery module is to combine individual batteries to increase the total battery capacity and voltage output, and to provide battery management and protection.

[0003] The battery module structure with a self-heating membrane, publication number CN108550734B, has a plurality of electric cells arranged in sequence, a plurality of separating holders attached one by one between adjacent electric cells, a heating membrane connected to the plurality of separating holders and abutting the electric cells, insulating end plates located at both ends in the arrangement direction of the electric cells, a fixed end plate attached to the insulating end plate on a side remote from the plurality of electric cells, metal side plates attached to both sides in the arrangement direction of the plurality of electric cells, both ends of the metal side plate fixedly connected to the fixed end plate, edges of the metal side plate are folded to form folding parts, and the folding parts cover the outside of the plurality of electric cells, a collecting cover attached to a side having electrode posts of the plurality of electric cells, and a top cover attached to the collecting cover on a side remote from the plurality of electric cells.

[0004] There are two heating methods for conventional battery modules: one is heating using a liquid cooling plate, and the other is heating using a heating film. The heating film is arranged by attaching it to the side of the electric cell. The conventional side-attaching method of the heating film, on the one hand, is prone to air bubbles during the assembly and attachment process, which causes the heating film to run dry during use. On the other hand, due to the vibration of the entire vehicle during use, the heating film can loosen, causing uneven heating and the electric cells to run dry. Furthermore, although there are temperature differences between the electric cells due to differences in the arrangement position and working environment, the heating power of the heating structure of the conventional battery module is all the same, so there are large temperature differences between the electric cells during heating, which reduces the performance and safety of the battery pack. Summary of the Invention [Problem to be solved by the invention]

[0005] In view of this, the present invention proposes a heating structure for a battery module and an installation method thereof. The heating structure is located at the bottom of the battery module, so that no air bubbles appear during assembly and it will not fall off due to vibration during long-term use, thereby improving the stability of the structure. At the same time, different heating powers are used for different heating zones of the heating structure, which can absorb the effects of temperature differences between battery cells due to differences in installation position and working environment, and effectively ensure the consistency of temperatures between different battery cells in the same battery module. [Means for solving the problem]

[0006] The technical solution of the present invention is realized as follows:

[0007] In a first aspect, the present invention provides a heating structure for a battery module, the heating structure comprising: a case, a battery module, and a heating assembly; A receiving groove is provided in the case, The battery module is installed in the receiving groove; The heating assembly is provided between the bottom of the accommodating groove and the battery module, and the heating assembly has a first heating zone and a second heating zone for heating different zones of the battery module, and the first heating zone and the second heating zone have different heating powers.

[0008] Based on the above technical solution, preferably, the heating assembly includes a plate and a resistance wire; the plate is disposed between the bottom of the receiving groove and the battery module, and the plate is an epoxy glass fiber board; the first heating zone and the second heating zone are both in the resistive wire; The resistance wire is provided inside the plate body, and both ends of the resistance wire are arranged side by side on the same side, and the resistance wire is used to heat the battery module.

[0009] Based on the above technical proposal, preferably, the resistance wire includes at least two bent portions, and the two opposing bent portions are symmetrically distributed along a vertical plane of the center line of the width of the plate body, and both ends on one side of the two opposing bent portions are fixedly connected, and both ends on the other side are arranged parallel to each other with a gap between them, and the resistance wire has an integral structure.

[0010] Based on the above technical solution, preferably, each of the at least two bending portions includes a plurality of U-shaped segments, and the plurality of U-shaped segments are sequentially connected along the longitudinal horizontal direction of the plate body.

[0011] Based on the above technical proposal, preferably, the diameter of the first heating zone is smaller than the diameter of the second heating zone, the second heating zone is located in the middle zone of the bending portion, and the first heating zone is located on both sides of the second heating zone.

[0012] According to the above technical solution, preferably, the device further includes a first adhesive layer and a thermally conductive adhesive layer; the first adhesive layer is provided between a groove bottom of the accommodating groove and the plate body, and is used to insulate the plate body from the case; The heat-conductive adhesive layer is disposed between the plate and the battery module and is used for conducting heat.

[0013] According to the above technical solution, preferably, the device further includes at least two position limiting members and a second adhesive layer; the at least two position limiting members are both provided on the groove bottom of the accommodating groove and are parallel to the longitudinal horizontal direction of the plate body, and the two opposing position limiting members are provided symmetrically with respect to a vertical plane of a center line of the width of the accommodating groove, the battery module abuts against surfaces of at least two of the position limiting members, the second adhesive layer is located on the outer sides of the two opposing position limiting members, and the second adhesive layer fills a gap between the battery module and a groove bottom of the accommodating groove; The first adhesive layer is positioned between two opposing position limiting members.

[0014] Based on the above technical solution, preferably, the area of ​​the zone enclosed between the two opposing position limiting members is equal to 2 / 3 of the area of ​​the bottom of the battery module.

[0015] According to the above technical solution, preferably, the position limiting member is flush with the height of the thermally conductive adhesive layer and the second adhesive layer.

[0016] In a second aspect, the present invention further provides a method for installing a heating structure for a battery module, the method being used for installing the heating structure for the battery module described above, comprising: S1: Adhere two position limiting members in the receiving groove, and determine that the area formed between the two position limiting members and the inner wall of the receiving groove is equal to 2 / 3 of the area of ​​the bottom of the battery module; S2: Applying a first adhesive layer between the two position limiting members, the first adhesive layer having a height lower than the height of the position limiting members, and placing a plate of the heating assembly between the two positioned position limiting members, and placing the surface of the plate and the first adhesive layer in a state where they overlap; S3: After the first adhesive layer and the plate body are fixed, a thermally conductive adhesive layer is applied to the surface of the plate body, and the height of the thermally conductive adhesive layer and the position limiting member are made equal; S4: Applying a second adhesive layer to the side where the two position limiting members are separated, the second adhesive layer having a height equal to the height of the position limiting members; S5. Arranging the battery modules on the surfaces of the two position limiting members, adhering and fixing the second adhesive layer and the thermal conductive adhesive layer to the bottom of the battery modules, and arranging the battery modules so that the center line of the width of the battery modules overlaps the center line of the width of the plate body. [Effects of the Invention]

[0017] The battery module heating structure and its mounting method of the present invention have the following beneficial effects over the prior art.

[0018] (1) By placing the heating assembly at the bottom of the battery module, no air bubbles will appear during assembly, and it will not fall off due to vibration during long-term use, which not only improves structural stability and ensures uniform heating, but also effectively avoids battery performance degradation and safety hazards caused by uneven heating. Furthermore, the first and second heating zones in the heating assembly use different heating powers, allowing for accurate heating according to the actual needs of the battery cells. This eliminates the effects of temperature differences due to differences in position and environment, effectively guarantees temperature consistency among different battery cells in the same battery module, and improves the performance and service life of the entire battery module.

[0019] (2) The bent portion increases the contact area between the resistance wire and the plate, thereby improving the heat conduction efficiency. At the same time, the resistance wire can generate a certain distortion when subjected to external force, thereby alleviating the stress concentration phenomenon and reducing the risk of fatigue failure due to long-term use.

[0020] (3) The plate and the electric cell are bonded with a thermally conductive adhesive layer, which not only prevents the flatness of the top surface of the plate and the bottom of the electric cell from affecting heating efficiency, but also prevents temperature differences from occurring in different zones of the same electric cell placed on the plate. A first adhesive layer is used to bond the plate and the case, which has poor thermal conductivity and prevents the plate from dissipating heat through the case, thereby improving the efficiency of the heating plate heating the electric cell.

[0021] (4) The mounting position of the plate is determined by the two position limiting members provided, and the plate is bonded to the case and the battery module via adhesive layers, thereby improving mounting efficiency.

[0022] (5) The plate covers only two-thirds of the bottom zone of the battery module, and the remaining bottom zone of the battery module is bonded to the case via the second adhesive layer. This not only increases the fixing strength of the battery module, but also covers the bottom of the electric cells, improves the heat retention performance of the electric cells, prevents the heat generated by the electric cells from being conducted to the case and dissipated, and satisfies the heating performance of the battery module. [Brief explanation of the drawings]

[0023] In order to more clearly describe the technical solutions in the embodiments of the present invention or the prior art, the following will briefly describe the drawings that need to be used in the description of the embodiments or the prior art. Of course, the drawings in the following description are only a part of the embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative work. [Figure 1] 1 is a perspective view of a heating structure for a battery module according to the present invention; [Figure 2] 1 is a perspective view of a heating assembly of a heating structure for a battery module according to the present invention; [Figure 3] 1 is a cross-sectional view of a heating assembly of a heating structure for a battery module according to the present invention; [Figure 4] 1 is a structural diagram of a resistance wire of a heating structure of a battery module according to the present invention; [Figure 5] 1 is a perspective view of the internal structure of a case of a heating structure for a battery module according to the present invention; [Figure 6] 3 is a side cross-sectional view of a case of the heating structure for a battery module according to the present invention. FIG. [Figure 7] 7 is an enlarged schematic view of a local area A in FIG. 6 of the heating structure for the battery module according to the present invention. [Figure 8] 2 is a schematic diagram illustrating the connection between an electric cell and a heating assembly in accordance with an embodiment of the heating structure of a battery module according to the present invention; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0024] The following provides a clear and complete description of the technical solutions in the embodiments of the present invention using the embodiments of the present invention, but it is clear that the described embodiments are only a part of the embodiments of the present invention and are not all of them. Based on the embodiments of the present invention, all other embodiments that can be obtained by those skilled in the art without any creative efforts shall fall within the scope of protection of the present invention.

[0025] There are two heating methods for conventional battery modules: one is heating using a liquid cooling plate, and the other is heating using a heating film. The heating film is arranged by attaching it to the side of the electric cell. The conventional side-attaching method of the heating film is prone to air bubbles during the assembly and attachment process, which causes the heating film to run dry during use. On the other hand, the heating film can loosen due to the vibration of the entire vehicle during use, causing uneven heating and the electric cell to run dry.

[0026] As shown in Figures 1 to 7, the heating structure of the battery module of the present invention includes a case 1, a battery module 2, and a heating assembly 3, in which an accommodating groove 100 is provided in the case 1, the battery module 2 is installed in the accommodating groove 100, and the heating assembly 3 is provided between the groove bottom of the accommodating groove 100 and the battery module 2, and the heating assembly 3 has a first heating zone 310 and a second heating zone 320 for heating different zones of the battery module 2, and the heating power of the first heating zone 310 and the second heating zone 320 is different.

[0027] Specifically, the battery module 2 in this embodiment includes electric cells, cable ties, end plates, and a CCS assembly. The battery module 2 is formed by stacking a plurality of electric cells in groups. The cable ties are used to bind the electric cells and the end plates, the end plates are used to prevent the end plates from approaching the electric cells, and the CCS assembly is used to collect the status of the electric cells. This is conventional technology, and further description is omitted here.

[0028] Furthermore, this battery module heating structure design not only improves heating efficiency, but also significantly improves the operating performance of the battery module 2 in cold environments. Because the heating assembly 3 is located at the bottom of the battery module 2, no air bubbles appear during assembly, and it will not fall off due to vibration during long-term use. This not only improves structural stability and ensures uniform heating, but also effectively avoids battery performance degradation and safety hazards caused by uneven heating.

[0029] The design of the heating assembly 3 also takes into account various conditions of the battery module in actual use. For example, cells at different positions in the battery module may have uneven temperature distribution due to differences in distance from the heating source or differences in operating environments such as ventilation conditions and external temperature. To address this issue, in this embodiment, the first heating zone 310 and the second heating zone 320 within the heating assembly 3 employ different heating powers, which allows accurate heating according to the actual needs of the battery cells and eliminates the effects of temperature differences due to differences in position and environment.

[0030] The heating structure of the battery module in this embodiment can effectively ensure the consistency of the temperature of the battery cells, improve the performance and service life of the entire battery module 2, and significantly improve the stability and reliability of the heating assembly 3, thereby reducing the risk of performance degradation or damage to the battery module due to failure of the heating assembly 3.

[0031] It is understood that the number of first heating zones 310 and second heating zones 320 installed is several, and the number and locations thereof are installed according to the temperature difference caused by the electric cells in different zones of the battery module 2, and the magnitude of the power of the installed heating zones is set according to the temperature difference that occurs in order to ensure the consistency of the temperature of each electric cell of the battery module 2.

[0032] In this embodiment, the heating assembly 3 includes a plate 31 and a resistance wire 32. The plate 31 is arranged between the bottom of the receiving groove 100 and the battery module 2. The plate 31 is an epoxy glass fiber board. The first heating zone 310 and the second heating zone 320 are both on the resistance wire 32. The resistance wire 32 is arranged inside the plate 31, and both ends of the resistance wire 32 are arranged side by side on the same side. The resistance wire 32 is used to heat the battery module 2.

[0033] The plate body (31) is made of an epoxy glass fiberboard material with excellent insulating properties and high temperature resistance, which can effectively isolate the electrical connection between the resistance wire 32 and the battery module 2 and prevent safety issues caused by electrical short circuits. At the same time, the epoxy glass fiberboard also has relatively high mechanical strength, which can withstand the vibrations and impacts generated by the battery module 2 during operation and ensure long-term and stable operation of the heating assembly. The resistance wire 32 is installed inside the plate body 31 as a heating element, which ensures efficient heat conduction between the resistance wire 32 and the battery module 2 and prevents damage to the resistance wire 32 that may occur if it is directly exposed to the external environment.

[0034] At the same time, both ends of the resistance wire 32 are arranged side by side on the same side, facilitating connection to an external control device. In addition, this embodiment further includes a heating harness, with two connection ends on each side of the heating harness, the two connection ends on one side of the heating harness are electrically connected to both ends of the resistance wire 32, and the two connection ends on the other side of the heating harness are electrically connected to one end of the external power supply and one end of the contact of the external relay, and the other end of the external power supply and the other end of the contact of the external relay are electrically connected, and the coil of the external relay is electrically connected to the output end of the battery BMS system and the input end of the external power supply.

[0035] Here, the CCS module is used to collect the status of the electric cells, and can be used to collect the temperature status of each electric cell of the battery module 2, and feed the collected temperature status of each electric cell of the battery module 2 back to the BMS system, and when the collected temperature value falls below the threshold, the BMS system controls the coil of the external relay to power up, closes the contact of the external relay, and the external power supply energizes the resistance wire 32 to heat the electric cell.

[0036] The resistance wire 32 is also provided with several first heating zones 310 and several second heating zones 320, each with a different heating power, which allows accurate heating according to the actual needs of different electric cells in the battery module 2, thereby eliminating the influence of temperature differences due to different positions and environments. By adjusting the heating power of different heating zones, uniform control of the temperature of the battery module can be achieved, and the operating performance and service life of the battery module 2 can be improved.

[0037] In this embodiment, the resistance wire 32 includes at least two bending portions 321, and the two opposing bending portions 321 are symmetrically distributed along a vertical plane of the center line of the width of the plate body 31, and both ends on one side of the two opposing bending portions 321 are fixedly connected, and both ends on the other side are arranged parallel to each other with a gap between them, and the resistance wire 32 has an integral structure.

[0038] Because the width of the electric cells of this battery module 2 is long, two bent portions 321 are symmetrically arranged along the longitudinal direction of the battery module, with the bent portions 321 slightly longer than the bottom length of the battery module. This symmetrical arrangement ensures a balanced heating assembly during the heating process and prevents localized overheating and cooling due to uneven heating. The resistance wire 32 effectively achieves uniform heating of the battery module 2. The presence of the bent portions 321 increases the contact area between the resistance wire 32 and the plate body 31, improving heat conduction efficiency. At the same time, the design of the bent portions 321 allows the resistance wire 32 to generate a more uniform heat field distribution during heating, preventing localized overheating due to heat concentration. Furthermore, the service life of the resistance wire 32 is improved. The presence of the bent portions 321 allows the resistance wire 32 to generate a certain strain when subjected to external force, mitigating stress concentration and reducing the risk of fatigue failure due to long-term use.

[0039] Here, each of the at least two bent portions 321 includes a plurality of U-shaped segments 3211, and the plurality of U-shaped segments 3211 are sequentially connected to one another along the longitudinal horizontal direction of the plate body 31.

[0040] Furthermore, each of the at least two bent portions 321 includes a plurality of U-shaped segments 3211. This structure not only increases the contact area between the resistance wire and the plate body 31, but also enables the resistance wire to generate a more uniform and stable heat field distribution during heating. The positions of the U-shaped segments 321 correspond one-to-one to the positions of each cell of the battery module 2. The resistance wire 32 can form a plurality of hot spots during heating, each hot spot corresponding to a respective cell of each battery module 2, allowing heat to be rapidly transferred to the battery module, and improving heating efficiency and uniformity.

[0041] Based on the above technical proposal, preferably, the diameter of the first heating zone 310 is smaller than the diameter of the second heating zone 320, the second heating zone 320 is located in the middle zone of the bending section 321, and the first heating zone 310 is located on both sides of the second heating zone 320, respectively.

[0042] Furthermore, the diameter of the first heating zone 310 is smaller than the diameter of the second heating zone 320, and this design allows the first heating zone 310 to generate relatively less heat when heated, while the second heating zone 320 can generate more heat.

[0043] Here, the formula for calculating the diameter D and power P of the heating plate resistor is P=I 2 R, and resistance R=ρL / S, where S=π(D / 2) 2 , where L is the length of the resistance wire, S is the cross-sectional area of ​​the resistance wire, and ρ is the resistance coefficient of the object.

[0044] This allows the heating power of the heating zone to be calculated through a formula, and the distribution of this differentiated heating power can be precisely adjusted based on the actual demand of the electric cells inside the battery module, thereby achieving precise control of the electric cell temperature.

[0045] At the same time, the first heating zone 310 is arranged on both sides of the second heating zone 320, respectively. This arrangement allows the first heating zone to heat the edges of the battery module, thereby preventing the electric cells at the edges from becoming too hot due to insufficient heat.

[0046] For example, the first heating zones 310 on both sides can be heated to achieve high heating power, and the second heating zone 320 in the middle can be heated to achieve low heating power. In this way, the heating assembly 3 can absorb the effects of temperature differences in the electric cells due to differences in placement position and operating environment by adopting different heating powers in different heating zones.

[0047] In this embodiment, the battery further includes a first adhesive layer 4 and a heat conductive adhesive layer 5. The first adhesive layer 4 is disposed between the groove bottom of the accommodating groove 100 and the plate body 31 and is used to insulate the plate body 31 from the case 1, and the heat conductive adhesive layer 5 is disposed between the plate body 31 and the battery module 2 and is used to conduct heat.

[0048] In addition, the plate 31 and the electric cell are bonded together via a thermally conductive adhesive layer 5, which prevents the flatness of the top surface of the plate 31 and the bottom of the electric cell from affecting heating efficiency and prevents temperature differences from occurring in different zones of the same electric cell placed above the plate 31. The plate 31 and the case 1 are bonded together using a first adhesive layer 4, which is cheaper than the thermally conductive adhesive layer 5 and has poor thermal conductivity, preventing the plate 31 from radiating heat through the case 1 and improving the efficiency with which the heating plate 31 heats the electric cell.

[0049] Specifically, the thermally conductive adhesive layer 5 in this embodiment is made of a resin matrix and a thermally conductive filler.

[0050] Here, the resin matrix includes epoxy resin, silicone, and polyurethane, and the thermally conductive filler includes aluminum nitride AlN, boron nitride BN, silicon nitride Si3N4, aluminum oxide A12O3, magnesium oxide MgO, and zinc oxide ZnO, which can enhance thermal conductivity.

[0051] In this embodiment, the battery module 2 further includes at least two position limiting members 6 and a second adhesive layer 7, wherein the at least two position limiting members 6 are both arranged on the bottom of the accommodating groove 100 and are parallel to the longitudinal horizontal direction of the plate body 31, the two opposing position limiting members 6 are arranged symmetrically with respect to the vertical plane of the center line of the width of the accommodating groove 100, the battery module 2 abuts against the surfaces of the at least two position limiting members 6, the second adhesive layer 7 is located outside the two opposing position limiting members 6, and the second adhesive layer 7 fills the gap between the battery module 2 and the bottom of the accommodating groove 100, and the first adhesive layer 4 is located between the two opposing position limiting members 6.

[0052] The position limiting member 6 is an insulating strip that not only ensures electrical isolation between the battery module 2 and the case 1, but also avoids the risk of short circuits caused by contact between metal parts. The installation of the second adhesive layer 7 further strengthens the connection strength between the battery module 2 and the case 1 and fills the gap between the battery module 2 and the bottom of the receiving groove 100, ensuring that the battery module 2 is tightly attached to the bottom of the groove, reducing the possibility of loosening or falling off due to vibration or impact, and improving the stability and safety of the structure.

[0053] In this embodiment, the area of ​​the zone enclosed between two opposing position limiting members 6 is equal to ⅔ of the area of ​​the bottom of the battery module 2 .

[0054] The plate body 31 covers only two-thirds of the bottom zone of the battery module 2, and the remaining bottom zone of the battery module 2 is adhered to the case 1 via the second adhesive layer 7. On the one hand, this increases the fixing strength of the battery module 2, and on the other hand, it covers the bottom of the electric cells, improving the heat retention performance of the electric cells and preventing the heat generated by the electric cells from being conducted to the case 1 and dissipated.

[0055] In addition, since the area of ​​the zone enclosed by the two opposing position limiting members 6 and the inner wall of the storage groove 100 is equal to 2 / 3 of the area of ​​the bottom of the battery module 2, the two position limiting members 6 also serve to position the mounting position of the plate body 31, making mounting easier and improving mounting efficiency.

[0056] The position limiting member 6 in this embodiment is flush with the height of the thermally conductive adhesive layer 5 and the second adhesive layer 7 .

[0057] Specifically, in this embodiment, two position limiting members 6 are provided in each accommodating groove 100, and the two position limiting members 6 are provided along the longitudinal direction of the accommodating groove 100, and both sides of the two position limiting members 6 abut against both side walls of the accommodating groove 100, respectively, dividing the accommodating groove 100 into three cavities, the first adhesive layer 4 is filled in the middle cavity, the second adhesive layer 7 is filled in the cavities on both sides, the bottom area of ​​the second adhesive layer 7 is the same as the bottom area of ​​the cavities on both sides, the height of the second adhesive layer 7 is equal to the height of the position limiting member 6, the bottom area of ​​the first adhesive layer 4 is equal to the bottom area of ​​the middle cavity, and the height of the first adhesive layer 4, together with the thickness of the plate body 31 and the thermal conductive adhesive layer 5, is equal to the height of the position limiting member 6.

[0058] Therefore, the heating efficiency is prevented from being affected by the flatness of the top surface of the plate 31 and the bottom of the cell, and the temperature difference between different zones of the same cell arranged above the plate 31 is also prevented.

[0059] Specifically, in this embodiment, the thickness H of the position limiting member 6 is 4 mm, the thickness H1 of the heating assembly 3 is 2 mm, the thickness H2 of the first adhesive layer 4 is 1.5 mm, the thickness H3 of the thermally conductive adhesive layer 5 is 1 mm, and the thickness H4 of the second adhesive layer 7 is 4.5 mm.

[0060] The thickness of the position limiting member 6 is H, and the parameter information of the inner adhesive layers of the two position limiting member 6 zones is H1 for the thickness of the heating assembly 3, H2 for the thickness of the first adhesive layer 4, and H3 for the thickness of the thermally conductive adhesive layer 5, and these parameters are related by H+0.5=H1+H2+H3.

[0061] The parameter information of the outer adhesive layers of the zones of the two position limiting members 6 is that the thickness of the second adhesive layer 7 is H4, and this parameter has the relationship H+0.5=H4.

[0062] To ensure that the time it takes for the bottom of the electric cell to reach the heating temperature value is shortest, H1+H3 must be as small as possible. The thickness H1 of the heating assembly 3 is calculated based on the diameter D of the heating plate resistor and the power P, and is set to a fixed thickness H1=2 mm.

[0063] The setting requirement is H-H1-H2-H3≧0.5. Because the current production process can only guarantee a flatness of 0.5 mm for the electric cells at the bottom of the module, this is set to 0.5 mm. Considering the manufacturing tolerance of the position limiting member 6 and the heating assembly 3 being 0.2 mm, an assembly tolerance of 0.1 mm is ensured. Furthermore, to reduce the heat transfer time from the heating assembly 3 to the bottom of the electric cells, the thickness H3 of the thermally conductive adhesive layer 5 must be as small as possible, so H3=1 mm. Furthermore, to reduce the heating energy loss of the heating assembly 3, the thickness H2 of the first adhesive layer 4 must be as large as possible. Considering that the case 1 is manufactured with a low flatness of only 1.2 mm, an assembly tolerance of 0.3 mm is ensured. Therefore, the thickness H2 of the first adhesive layer 4 = 1.5 mm. Therefore, the thickness H of the position limiting member 6 is calculated as 4 mm.

[0064] The present invention further provides a method for installing a heating structure of a battery module, the method comprising: S1: Adhere two position limiting members 6 in the receiving groove 100, and determine that the area formed between the two position limiting members 6 and the inner wall of the receiving groove 100 is equal to 2 / 3 of the area of ​​the bottom of the battery module 2; S2: Applying a first adhesive layer 4 between two position limiting members 6 to a height lower than that of the position limiting members 6, and placing the plate body 31 of the heating assembly 3 between the positioned two position limiting members 6, and placing the surfaces of the plate body 31 and the first adhesive layer 4 in an overlapping state; S3: After fixing the first adhesive layer 4 and the plate body 31, a heat conductive adhesive layer 5 is applied to the surface of the plate body 31, and the height of the heat conductive adhesive layer 5 and the position limiting member 6 are made equal; S4: Applying a second adhesive layer 7 having a height equal to the height of the position limiting member 6 on the side where the first adhesive layer 4 and the two position limiting members 6 are separated; S5, placing the battery module 2 on the surface of the two position limiting members 6, adhering and fixing the second adhesive layer 7 and the thermally conductive adhesive layer 5 to the bottom of the battery module 2, and arranging the battery module 2 so that the center line of the width of the battery module 2 overlaps the center line of the width of the plate body.

[0065] Example

[0066] As shown in FIG. 8, in this embodiment, the length of the electric cell is L, the height of the electric cell is H, the width of the heating plate is W, the maximum temperature of the top surface of the cell is T1, the minimum temperature of the top surface of the cell is T2, the maximum temperature of the side edge of the cell is T3, and the minimum temperature of the side edge of the cell is T4.

[0067] After determining the set values ​​of the length L of the electric cell, the height H of the electric cell, and the power P of the heating plate, experimental tests were conducted to obtain the relationship between the width W of the heating plate, the length L of the electric cell, the temperature difference in the top zone of the electric cell, and the temperature difference in the side zone of the electric cell.

[0068] The experimental method is as follows.

[0069] Test setup: A large number of thermal NTCs are placed on the top surface of the electric cell and on the side of the electric cell, and the widths of the different heating plates are W1>W2>W3>W4>W5, where W1=2.2 / 3L, W2=2.1 / 3L, W3=2 / 3L, W4=1.9 / 3L, W5=1.8 / 3L.

[0070] Test conditions Condition 1: In an environment of -20°C, heating was carried out by the heating assembly 3 until the maximum temperature of the top surface or side of the electric cell reached 10°C. Condition 2: In an environment of -10°C, heating was carried out by the heating assembly 3 until the maximum temperature of the top surface or side of the electric cell reached 10°C. Condition 3: In an environment of 0°C, heating was carried out by the heating assembly 3 until the maximum temperature of the top surface or side of the electric cell reached 10°C.

[0071] The test results are as follows: W1 = 2.2 / 3L, W2 = 2.1 / 3L, W3 = 2 / 3L, W4 = 1.9 / 3L, W5 = 1.8 / 3L, and the maximum temperature T1 on the top surface of the cell, the minimum temperature T2 on the top surface of the cell, the maximum temperature T3 on the side of the cell, the minimum temperature T4 on the side of the cell, the cell length L, and the cell height H are all fixed values, where L = 2.7H.

[0072] Under different test conditions, the temperature of each zone is as shown in the table below after heating until the maximum temperature of the top surface or side of the electric cell reaches 10°C. [Table 1]

[0073] From the above experimental data, When the width of the heating plate is set to W3, W4 or W5, the upper surface temperature collector can monitor the maximum temperature of the entire electric cell. When the width of the heating plate is set to W3, it reaches 2 / 3 of the width distance of the cell, and it can be confirmed that the temperature difference between the cells is the smallest at this time, and the temperature consistency of different cells in the same module is better.

[0074] The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A heating structure for a battery module, The battery includes a case (1), a battery module (2), and a heating assembly (3), A receiving groove (100) is provided in the case (1), The battery module (2) is installed in the receiving groove (100), The heating assembly (3) is provided between the bottom of the receiving groove (100) and the battery module (2), and the heating assembly (3) includes a first heating zone (310) and a second heating zone (320) for heating different zones of the battery module (2), and the first heating zone (310) and the second heating zone (320) have different heating powers. A heating structure for a battery module.

2. The heating assembly (3) includes a plate (31) and a resistance wire (32); The plate body (31) is provided between the groove bottom of the accommodation groove (100) and the battery module (2), and the plate body (31) is an epoxy glass fiber board; the first heating zone (310) and the second heating zone (320) are both in the resistive wire (32); The resistance wire (32) is provided inside the plate body (31), both ends of the resistance wire (32) are arranged side by side on the same side, and the resistance wire (32) is used to heat the battery module (2).

2. The heating structure for a battery module according to claim 1.

3. The resistance wire (32) includes at least two bent portions (321), and the two opposing bent portions (321) are symmetrically distributed along a plane perpendicular to the center line of the width of the plate body (31), and both ends of one side of the two opposing bent portions (321) are fixedly connected, and both ends of the other side are arranged parallel to each other with a gap therebetween, and the resistance wire (32) has an integral structure.

3. The heating structure for a battery module according to claim 2.

4. Each of the at least two bent portions (321) includes a plurality of U-shaped segments (3211), and the plurality of U-shaped segments (3211) are sequentially connected to one another along the longitudinal horizontal direction of the plate body (31).

4. The heating structure for a battery module according to claim 3.

5. The diameter of the first heating zone (310) is smaller than the diameter of the second heating zone (320), the second heating zone (320) is located in the middle zone of the folding portion (321), and the first heating zone (310) is located on both sides of the second heating zone (320).

4. The heating structure for a battery module according to claim 3.

6. It further comprises a first adhesive layer (4) and a thermally conductive adhesive layer (5), The first adhesive layer (4) is provided between the groove bottom of the accommodating groove (100) and the plate body (31) and is used to insulate the plate body (31) from the case (1); The heat-conductive adhesive layer (5) is provided between the plate body (31) and the battery module (2) and is used for conducting heat.

3. The heating structure for a battery module according to claim 2.

7. It further comprises at least two position limiting members (6) and a second adhesive layer (7), The at least two position limiting members (6) are both provided at the bottom of the receiving groove (100) and are parallel to the longitudinal horizontal direction of the plate body (31), and the two opposing position limiting members (6) are provided symmetrically with respect to a vertical plane of the center line of the width of the receiving groove (100); The battery module (2) abuts against the surfaces of at least two of the position limiting members (6), the second adhesive layer (7) is located outside the two opposing position limiting members (6), and the second adhesive layer (7) fills the gap between the battery module (2) and the bottom of the accommodation groove (100); The first adhesive layer (4) is located between two opposing position limiting members (6).

7. The heating structure for a battery module according to claim 6.

8. The area of ​​the zone enclosed between the two opposing position limiting members (6) is equal to 2 / 3 of the area of ​​the bottom of the battery module (2).

8. The heating structure for a battery module according to claim 7.

9. The position limiting member (6) is flush with the height of the thermally conductive adhesive layer (5) and the second adhesive layer (7).

9. The heating structure for a battery module according to claim 8.

10. A method for attaching a heating structure to a battery module, comprising: A battery module heating structure according to any one of claims 1 to 9 is used to mount the battery module heating structure, S1: Adhere two position limiting members (6) in the receiving groove (100) and determine that the area enclosed by the two position limiting members (6) and the inner wall of the receiving groove (100) is equal to 2 / 3 of the area of ​​the bottom of the battery module (2); S2: Applying a first adhesive layer (4) between two position limiting members (6) with a height lower than that of the position limiting members (6), and placing a plate (31) of the heating assembly (3) between the two positioned position limiting members (6), and placing the surface of the plate (31) and the surface of the first adhesive layer (4) in a state where they overlap; S3: After fixing the first adhesive layer (4) and the plate body (31), a heat conductive adhesive layer (5) is applied to the surface of the plate body (31), and the height of the heat conductive adhesive layer (5) and the position limiting member (6) is made equal; S4: Applying a second adhesive layer (7) to the side where the two position limiting members (6) are separated, the second adhesive layer (7) having a height equal to the height of the position limiting members (6); S5: placing the battery module (2) on the surface of the two position limiting members (6), adhering and fixing the second adhesive layer (7) and the heat conductive adhesive layer (5) to the bottom of the battery module (2), and arranging the battery module (2) so that the center line of the width of the battery module (2) overlaps the center line of the width of the plate body; A method for attaching a heating structure to a battery module, comprising:

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