CN218849593U - Battery module thermal runaway protector - Google Patents

Abstract

The utility model relates to a battery module thermal runaway protector. The battery module thermal runaway protector comprises a bottom liquid cooling plate which is arranged at the bottom of a battery module; the first side surface liquid cooling plate and the second side surface liquid cooling plate are oppositely arranged on two sides of the length direction of the battery module and are fixed on the bottom surface liquid cooling plate; the first end plate and the second end plate are oppositely arranged on two sides of the battery module in the width direction, and two sides of the first end plate and the second end plate are respectively fixed on the first side surface liquid cooling plate and the second side surface liquid cooling plate; the bottom surface liquid cooling plate, the first side surface liquid cooling plate, the second side surface liquid cooling plate, the first end plate and the second end plate are encircled to form a cavity for containing the battery module, and liquid cooling passages which are communicated with each other are arranged in the bottom surface liquid cooling plate, the first side surface liquid cooling plate and the second side surface liquid cooling plate and used for introducing cooling liquid. The utility model provides a battery module thermal runaway protector can guarantee the temperature homogeneity in the whole car test bin, can guarantee the battery module heat dissipation, effectively restraines battery module thermal runaway.

Description

Battery module thermal runaway protector

Technical Field

The utility model relates to a power battery thermal safety technical field especially relates to a battery module thermal runaway protector.

Background

Currently, in mainstream new energy electric vehicles, lithium ion batteries are most widely used due to the advantages of high energy density, long cycle life, fast charging speed and the like. The lithium ion battery anode material comprises lithium iron phosphate, lithium cobaltate, ternary lithium and the like, wherein the lithium ion battery taking the ternary lithium as the battery anode material has high energy density, high grouping efficiency and large use amount. However, ternary lithium batteries are poor in temperature resistance and safety, thermal runaway is easy to occur in a high-temperature environment, and then the thermal runaway is spread to surrounding batteries through thermal diffusion to cause module-level thermal runaway and vehicle accidents. The safety problem of the power battery becomes one of the important factors restricting the development of the electric automobile at present.

At present mainstream liquid cooling heat management technology mainly carries out the heat management control of normal heat dissipation and heating to the battery module to battery module bottom, and when taking place the thermal runaway, whole radiating rate is slow, is difficult to restrain or even clears up the thermal runaway risk.

In view of this, the utility model provides a can restrain protector that thermal runaway stretchs guarantees the heat dissipation of the normal operating of battery module on the one hand, on the other hand, the utility model provides a thermal protector with high-efficient heat dissipation and thermal-insulated synergism can effectively restrain battery module thermal runaway and stretch to other batteries.

SUMMERY OF THE UTILITY MODEL

To the above-mentioned problem of prior art, the utility model provides a battery module thermal runaway protector can guarantee the battery module heat dissipation, effectively restraines battery module thermal runaway.

Specifically, the utility model provides a battery module thermal runaway protector, the battery module includes a plurality of interval arrangements's battery piece, the big face of battery piece is parallel to each other, thermal runaway protector includes:

the bottom liquid cooling plate is arranged at the bottom of the battery module and used for absorbing heat generated at the bottom of the battery module;

the first side surface liquid cooling plate and the second side surface liquid cooling plate are oppositely arranged on two sides of the battery module in the length direction, are fixed on the bottom surface liquid cooling plate and are used for absorbing heat generated on two sides of the battery module;

the first end plate and the second end plate are oppositely arranged on two sides of the battery module in the width direction, and two sides of the first end plate and the second end plate are respectively fixed on the first side surface liquid cooling plate and the second side surface liquid cooling plate;

the bottom surface liquid cooling plate, the first side surface liquid cooling plate, the second side surface liquid cooling plate, the first end plate and the second end plate are encircled to form a cavity for containing the battery module, and liquid cooling passages which are mutually communicated are arranged in the bottom surface liquid cooling plate, the first side surface liquid cooling plate and the second side surface liquid cooling plate and used for introducing cooling liquid.

According to the utility model discloses an embodiment be equipped with insulating pad between battery module and the bottom surface liquid cooling board.

According to the utility model discloses an embodiment is adjacent be equipped with the insulating layer between the big face of battery piece, the insulating layer laminating the big face of battery piece, the insulating layer is made by ultralow thermal conductivity material.

According to an embodiment of the present invention, the heat insulation layer is a mica sheet layer, or a composite layer formed by laminating the mica sheet layer and the aerogel layer.

According to an embodiment of the present invention, the thickness of the thermal insulation layer is 3.5-4.5 mm.

According to the utility model discloses an embodiment, the both sides of first, second end plate are outwards bent and are formed the portion of bending the both sides of first, second side liquid cooling board are equipped with first pilot hole, the portion of bending is equipped with the second pilot hole, the portion of bending passes through the bolt fastening to first, second side liquid cooling board, the bolt with first, second pilot hole screw-thread fit is fixed.

According to an embodiment of the present invention, the bending angle of the bending portion is 95 to 120 °.

According to an embodiment of the present invention, a first liquid inlet pipe, a liquid outlet shunt pipe, a first liquid outlet pipe and a liquid inlet shunt pipe are arranged on the bottom liquid cooling plate;

and the first side surface liquid cooling plate and the second side surface liquid cooling plate are provided with a second liquid inlet pipe and a second liquid outlet pipe, the liquid outlet flow dividing pipe is communicated with the second liquid inlet pipe, and the liquid inlet flow dividing pipe is communicated with the second liquid outlet pipe.

According to an embodiment of the present invention, the liquid cooling channel comprises a first static pressure chamber, a second static pressure chamber, a main flow channel and a side flow channel;

two first static pressure chambers are arranged on two sides of the bottom surface liquid cooling plate in the length direction, a plurality of main flow channels communicated with the two first static pressure chambers are arranged on the bottom surface liquid cooling plate, the first liquid inlet pipe and the liquid outlet flow dividing pipe are arranged on one first static pressure chamber, and the first liquid outlet pipe and the liquid inlet flow dividing pipe are arranged on the other first static pressure chamber;

the first side surface and the second side surface of the liquid cooling plate are respectively provided with a first static pressure chamber and a second static pressure chamber, the first side surface and the second side surface of the liquid cooling plate are respectively provided with a plurality of side flow channels communicated with the first static pressure chambers, the first liquid inlet pipe is arranged on one first static pressure chamber, and the second liquid outlet pipe is arranged on the other second static pressure chamber.

According to an embodiment of the present invention, the flow channel axis of the side flow channel and the surfaces of the first and second side liquid cooling plates form an included angle of 20 to 45 °.

The utility model provides a pair of battery module thermal runaway protector through setting up bottom surface liquid cooling board, first, second side liquid cooling board, promotes the heat dispersion of battery module in a plurality of directions to effectively restrain the battery module thermal runaway.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:

fig. 1 shows a schematic structural diagram of a thermal runaway protector for a battery module according to an embodiment of the invention.

Fig. 2 shows a schematic view of the bottom liquid-cooled panel of fig. 1.

Fig. 3 shows a cross-sectional view of the bottom liquid-cooled panel of fig. 1.

Fig. 4 shows a schematic view of the first and second side liquid cold plates of fig. 1.

FIG. 5 illustrates a cross-sectional view of the first and second side liquid cold plates of FIG. 1.

Fig. 6 shows a partial cross-sectional view of a battery module thermal runaway protector according to an embodiment of the invention.

Fig. 7 shows a cross-sectional view of a battery module thermal runaway protector according to an embodiment of the invention.

Fig. 8 shows a graph of a thermal spread temperature of a battery module using a 2mm mica sheet layer.

Fig. 9 shows a graph of the thermal spread temperature of a battery module using a 4mm mica sheet layer.

Fig. 10 shows a graph of thermal spread temperature of a battery module employing a 2mm mica sheet layer and having only bottom surface liquid cooling.

Wherein the figures include the following reference numerals:

thermal runaway protector 100

Battery block 101

Bus bar 102

Bottom liquid cooling plate 103

First side liquid cold plate 104

Second side liquid cooling plate 105

First end plate 106

Second end plate 107

Insulating pad 108

First liquid inlet pipe 109

Liquid outlet shunt pipe 110

First liquid outlet pipe 111

Liquid inlet flow-dividing pipe 112

The second liquid inlet pipe 113

Second effluent pipe 114

A first static pressure chamber 115

A second static pressure chamber 116

Main flow channel 117

Side runner 118

Bolt hole site 119

Mounting boss 120

Bending part 121

First assembly hole 122

Thermocouple 123

Insulation layer 124

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the application, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the description of the present application, it is to be understood that the orientation or positional relationship indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the orientation or positional relationship shown in the drawings, and are used for convenience of description and simplicity of description only, and in the case of not making a reverse description, these directional terms do not indicate and imply that the device or element being referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore, should not be considered as limiting the scope of the present application; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

For ease of description, spatially relative terms such as "over 8230 \ 8230;,"' over 8230;, \8230; upper surface "," above ", etc. may be used herein to describe the spatial relationship of one device or feature to another device or feature as shown in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary terms "at 8230; \8230; 'above" may include both orientations "at 8230; \8230;' above 8230; 'at 8230;' below 8230;" above ". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of protection of the present application is not to be construed as being limited. Further, although the terms used in the present application are selected from publicly known and used terms, some of the terms mentioned in the specification of the present application may be selected by the applicant at his or her discretion, the detailed meanings of which are described in relevant parts of the description herein. Further, it is required that the present application is understood not only by the actual terms used but also by the meaning of each term lying within.

Fig. 1 shows a schematic structural diagram of a thermal runaway protector for a battery module according to an embodiment of the invention. As shown in the figure, the utility model provides a battery module thermal runaway protector 100. The battery module comprises a plurality of battery blocks 101 which are arranged at intervals, wherein the battery blocks 101 have the same size, and the large surfaces of the battery blocks 101 are parallel to each other. Conventionally, the battery block 101 is a rectangular parallelepiped, and two planes having the largest area among six planes of the rectangular parallelepiped are parallel to each other, and the plane having the largest area is referred to as a large plane of the battery block 101. The positive and negative electrodes of the battery blocks 101 are alternately connected by the bus bars 102 and are connected in series to form a medium-or high-voltage battery pack.

Specifically, in the present embodiment, the battery block 101 is a commercial 50Ah square ternary lithium ion battery. The structure size is 148mm multiplied by 98mm multiplied by 28mm, and the working voltage is 2.8V-4.25V. The entire battery module is composed of 8 prismatic battery blocks 101 connected in series in 2-parallel 4-series, and is connected to the tabs of the battery blocks 101 via bus bars 102. By way of example and not limitation, the battery module may be constructed using other types and numbers of battery blocks 101.

The thermal runaway protector 100 generally includes a bottom liquid cooled plate 103, first and second side liquid cooled plates 104, 105, and first and second end plates 106, 107.

Wherein, the bottom surface liquid cooling plate 103 is disposed at the bottom of the battery module. The bottom liquid cooling plate 103 is used for absorbing heat generated at the bottom of the battery module.

The first side surface liquid cooling plate 104 and the second side surface liquid cooling plate 105 are oppositely arranged on two sides of the length direction of the battery module and fixed on the bottom surface liquid cooling plate 103. The first and second side liquid cooling plates 104 and 105 are used for absorbing heat generated at two sides of the battery module.

The first and second end plates 106, 107 are oppositely disposed on both sides in the width direction of the battery module. The first and second end plates 106, 107 are fixed to the first and second side liquid-cooled plates 104, 105 at both sides thereof, respectively.

The bottom liquid cooling plate 103, the first and second side liquid cooling plates 104 and 105, and the first and second end plates 106 and 107 enclose a cavity for accommodating the battery module. Liquid cooling passages communicated with each other are arranged in the bottom liquid cooling plate 103 and the first and second side liquid cooling plates 104 and 105. And introducing cooling liquid into the liquid cooling passage to absorb heat generated by the battery module from the bottom surface and the side surface of the battery module. This kind of structure has improved the heat-sinking capability of whole battery module, reduces the difference in temperature of the upper portion and the lower part of battery module, improves whole temperature homogeneity, slows down the performance decay of battery module.

Preferably, an insulating pad 108 is disposed between the battery module and the bottom surface liquid cooling plate 103. Similarly, an insulating pad 108 is disposed between the battery module and the first and second side liquid cooled plates 104, 105. The thickness of the insulating pad 108 is set to about 1mm.

Preferably, a thermal insulation layer 124 is provided between the large faces of adjacent battery blocks 101. The thermal insulation layer 124 is attached to the large face of the battery block 101, and the thermal insulation layer 124 is made of an ultra-low thermal conductivity material. As shown, in this embodiment, 7 insulating layers 124 are provided to match 8 battery bricks 101. An insulating layer 124 is sandwiched between adjacent battery blocks 101. In the actual use process of the battery module, once a certain battery block 101 works abnormally, the battery block 101 generates heat seriously, the internal materials of the battery block 101 are damaged due to the temperature rise, thermal runaway occurs, and a large amount of heat is accumulated, so that the temperature rise can reach about 900 ℃. The resulting large amount of heat is transferred to the surroundings, thereby increasing the temperature of the adjacent battery blocks 101. The thermal insulation layer 124 functions to insulate a thermal runaway, i.e., to prevent or reduce heat transfer from a thermal runaway cell block 101 to an adjacent cell block 101.

Preferably, the thermal insulation layer 124 is a mica sheet layer, or a composite layer of the mica sheet layer and the aerogel layer. In particular, the thermal insulation layer 124 may be a mica sheet layer fitted in the gap between adjacent battery blocks 101 to reduce heat transfer between the battery blocks 101. The thermal insulation layer 124 may also be a composite layer of a mica sheet layer and an aerogel layer, for example, a piece of aerogel layer is disposed between two mica sheet layers, which can also reduce heat transfer between the battery blocks 101 and inhibit thermal runaway propagation. In addition, the thermal insulation layer 124 having such a structure can absorb a part of expansion stress by deformation when the battery block 101 is charged or thermally expanded. The thickness of the heat insulation layer 124 is 1-5 mm. More preferably, the thickness of the thermal insulation layer 124 is 3.5 to 4.5mm.

Fig. 2 shows a schematic view of the bottom liquid-cooled panel of fig. 1. Fig. 3 shows a cross-sectional view of the bottom liquid-cooled panel 103 of fig. 1. Fig. 4 shows a schematic view of the first and second side liquid cold plates of fig. 1. FIG. 5 illustrates a cross-sectional view of the first and second side liquid cold plates of FIG. 1. As shown in fig. 1, a first liquid inlet pipe 109, a liquid outlet branch pipe 110, a first liquid outlet pipe 111, and a liquid inlet branch pipe 112 are disposed on the bottom liquid cooling plate 103. The first and second side liquid cold plates 104, 105 are provided with a second liquid inlet pipe 113 and a second liquid outlet pipe 114. The liquid outlet branch pipe 110 is communicated with a second liquid inlet pipe 113, and the liquid inlet branch pipe 112 is communicated with a second liquid outlet pipe 114.

Preferably, the liquid cooling passage includes a first static pressure chamber 115, a second static pressure chamber 116, a primary flow passage 117, and a side flow passage 118. Referring to fig. 2, two first static pressure chambers 115 are provided at both sides of the bottom surface liquid cooling plate 103 in the length direction. The bottom surface liquid cooling plate 103 is provided with a plurality of main flow passages 117 communicating with the two first static pressure chambers 115. The first inlet pipe 109 and the two outlet manifolds 110 are arranged in a first static pressure chamber 115. A first outlet pipe 111 and two inlet manifolds 112 are provided in a further first static pressure chamber 115. In the present embodiment, 20 main flow channels 117 of a parallel structure are arranged on the bottom liquid cooling plate 103, and the main flow channels 117 are small rectangular cross-section flow channels. The height of the main flow channel 117 is 2mm, the width is 4-6 mm, and the wall thickness of the bottom liquid cooling plate 103 is 2mm. The width of the fin between two adjacent main flow channels 117 is 2-4 mm. The length and width of the first static pressure chamber 115 is 142 x 20mm. The first inlet pipe 109, the outlet branch pipe 110, the first outlet pipe 111 and the inlet branch pipe 112 are provided with reinforcing bosses at the connecting positions with the first static pressure chamber 115. The bottom liquid cooling plate 103 can be machined or stamped by a runner.

Referring to fig. 3 and 4, second static pressure chambers 116 are disposed on both sides of the first and second side liquid-cooled plates 104, 105 in the length direction. A plurality of side flow channels 118 which are communicated with the second static pressure chambers 116 at two sides are arranged on the first side surface liquid cooling plate 104 and the second side surface liquid cooling plate 105. The second inlet pipe 113 is arranged in one second static pressure chamber 116 and the second outlet pipe 114 is arranged in the other second static pressure chamber 116. In this embodiment, the first side liquid cooling plate 104 and the second side liquid cooling plate 105 have the same structure. Taking the first side liquid-cooled plate 104 as an example, referring to fig. 4, 8 side flow channels 118 in a parallel structure are arranged on the first side liquid-cooled plate 104, and the side flow channels 118 are small rectangular cross-section flow channels. The side flow channel 118 has a height of 1.6mm and a width of 2 to 6mm. The first side liquid cold plate 104 has a wall thickness of 1.2mm. The interval thickness between two adjacent side runners 118 is 1-6 mm. The length and width of the second static pressure chamber 116 is 74 x 15mm.

Referring to fig. 2 and 3, in the present embodiment, two liquid outlet branch pipes 110 and the first liquid inlet pipe 109 are arranged on one first static pressure chamber 115, that is, the two liquid outlet branch pipes 110 and the first liquid inlet pipe 109 are communicated with the first static pressure chamber 115. The outlet manifolds 110 each have a flared flow passage with a tapered opening size for collecting the cooling liquid entering the first static pressure chamber 115 from the first inlet pipe 109. The included angle between the axis of the liquid outlet shunt pipe 110 and the surface of the liquid cooling plate 103 on the bottom surface is 20-45 degrees. The bell mouth flow channel can reduce the flow resistance of the cooling liquid by combining the design of the included angle, and the flow uniformity is improved. Correspondingly, a first outlet pipe 111 and two inlet manifolds 112 are provided on the further first plenum 115. Similarly, the inlet manifold 112 is constructed and functions in the same way as the outlet manifold 110. An inlet manifold 112 is provided to collect cooling liquid from a second outlet pipe 114 into a first static pressure chamber 115. The liquid outlet flow-dividing pipe 110 and the second liquid inlet pipe 113, and the liquid inlet flow-dividing pipe 112 and the second liquid outlet pipe 114 are communicated through rubber hoses, so that the bottom liquid cooling plate 103 is respectively communicated with the liquid cooling passages of the first side liquid cooling plate 104 and the second side liquid cooling plate 105. Specifically, the cooling liquid flows from the first inlet pipe 109 into the first static pressure chamber 115, and after being split, a part of the cooling liquid flows into the other first static pressure chamber 115 through the main flow passage 117. The rest of the cooling liquid passes through the two liquid outlet branch pipes 110 and enters the second static pressure chambers 116 of the first and second side liquid-cooling plates 104 and 105 through the second liquid inlet pipe 113. The cooling liquid enters each of the other second static pressure chambers 116 through side channels 118. Then flows through an inlet manifold 112 via a second outlet pipe 114 and merges into a further first static pressure chamber 115. The cooling liquid is finally discharged from the first outlet pipe 111. The cooling liquid passes through the liquid cooling passages which are communicated with each other in the bottom surface liquid cooling plate 103 and the first and second side surface liquid cooling plates 104 and 105, and three surfaces of the bottom surface and the two side surfaces of the battery module are efficiently cooled. The cross-sectional area of the side flow channel 118 is slightly smaller than that of the main flow channel 117, so as to ensure the flow rate uniformity of the cooling liquid and help to reduce the overall weight and volume of the battery module thermal runaway protector 100. It will be readily appreciated that the flow of cooling liquid may also be reversed. For example, the positions of the first liquid inlet pipe 109 and the first liquid outlet pipe 111 are interchanged, and the positions of the liquid outlet branch pipe 110 and the liquid inlet branch pipe 112, and the positions of the second liquid inlet pipe 113 and the second liquid outlet pipe 114 are interchanged, so that the cooling liquid in the whole liquid cooling passage flows reversely.

Preferably, the bottom liquid cooling plate 103 is provided with 5 bolt hole sites 119 with a diameter of 4mm at equal intervals on the upper and lower sides in fig. 2. Correspondingly, the first side liquid cooling plate 104 is provided with a mounting boss 120 at the bottom in fig. 4, and 5 bolt hole sites 119 with the diameter of 4mm are arranged on the mounting boss 120. The bottom liquid cooling plate 103 and the first side liquid cooling plate 104 are fixed by bolts, and the bolts penetrate into corresponding bolt hole positions 119. Similarly, the bottom liquid-cooled plate 103 and the second side liquid-cooled plate 105 are fixed by bolts.

Preferably, the channel axis of the side channel 118 forms an included angle of 20 to 45 degrees with the surfaces of the first and second side liquid cooling plates 104 and 105, so as to reduce the flow resistance of the cooling liquid and improve the flow uniformity.

Preferably, referring to fig. 4, the first and second side liquid-cooled plates 104 and 105 employ side channels 118 having a wide cross section near the top of the battery module and side channels 118 having a narrow cross section near the bottom of the battery module. This allows more fluid to pass through the upper side flow channels 118, thereby improving the heat dissipation capacity of the upper portion of the battery module. The thermal resistance of the side flow path 118a having a width of 6mm (the width here means in the up-down direction of fig. 5) is significantly lower than that of the side flow path 118 having a width of 2mmb under the same inlet-outlet conditions and pressure difference. For example, at 2000Pa differential pressure, it can be calculated from the reference (Hengyun Zhang, missing Che, tingyu Lin, wensheng ZHao, modeling, analysis, design and Tests for Electronic Packaging and Moore, elsevier publication, 2020) that the upper side flow channel 118 of 6mm width has a lower surface thermal resistance than the lower 2mm width side flow channel 118, and the liquid cooling resistance at 2000Pa differential pressure differs by 1.3e to 4Km ² W, heat dissipation area of side liquid cooling plate is 10 multiplied by 266mm ² 200W heat dissipation, 6mm wideThe temperature of the side flow path 118a decreases by 1.3 e-4/(0.01 × 0.266) × 200=9.8 ℃ more than that of the side flow path 118b having a width of 2mm. The heat dissipation capacity of the upper part of the battery is improved by the arrangement mode of the side runners 118 with the widths gradually reduced from top to bottom, so that the temperature of the upper part of the battery module (corresponding to the highest temperature of the battery module) is further reduced, the temperature difference between the upper part and the lower part of the battery is reduced, and the temperature consistency and the thermal safety performance of the battery are improved.

Fig. 6 shows a partial cross-sectional view of a battery module thermal runaway protector according to an embodiment of the invention. Because the first and second side liquid cooling plates 104 and 105 and the first and second end plates 106 and 107 have the same connecting structure. Taking the first side liquid cooling plate 104 and the first end plate 106 as an example, referring to fig. 6 and 4, two sides of the first end plate 106 are bent outward to form a bent portion 121. Two sides of the first side liquid cooling plate 104 are provided with 3 first assembling holes 122 (bolt holes). The bent portion 121 is provided with 3 second attachment holes (bolt holes). The bent portion 121 is fixed to the first side liquid cooling plate 104 by bolts, and the bolts are fixed to the first assembling holes 122 and the second assembling holes in a threaded fit manner. The same structure is used to secure the first and second end plates 106, 107 between the first and second side liquid-cooled plates 104, 105. The first and second end plates 106, 107 can restrict the displacement of the battery module in the longitudinal direction thereof. First pilot hole 122 and second pilot hole correspond, for fillet rectangle hole site, allow bolt regulation fore-and-aft distance, bolt fixed connection leaves the fillet clearance, and the degree of laminating of first, second side liquid cold drawing 104, 105 and battery module can be adjusted through adjusting bolt's elasticity to reserve battery module assembly displacement inflation volume.

Preferably, the bending angle of the bending portion 121 is 95 to 120 °. The expansion gap between the first and second end plates 106, 107 and the first and second side liquid-cooling plates 104, 105 is reserved for about 1.5mm. When the battery module is fully charged, gas generated or thermally expanded, the bolt fixing pre-tightening force between the first and second end plates 106, 107 and the first and second side liquid cooling plates 104, 105 is increased, so as to maintain the tight assembly of the battery module. In other words, a bolt pre-tightening gap is reserved, so that the joint stress of the first side liquid cooling plate 104, the second side liquid cooling plate 105 and the battery module can be conveniently adjusted by adjusting the bolt pre-tightening force. Generally, the bonding stress should be maintained within the range of 0.5 to 3 atmospheres.

Fig. 7 shows a cross-sectional view of a battery module thermal runaway protector according to an embodiment of the invention. As shown in the drawing, the battery blocks 101 numbered 1 to 8 are arranged in order, 8 thermocouples 123 are arranged at the center position of the large face of each battery, and the measured temperature is taken as the temperature of the corresponding battery block 101.

According to practical experience and a lot of experiments, the heat insulation layer 124 arranged between the large surfaces of the adjacent battery blocks 101 is preferably a mica sheet layer, the thickness of the heat insulation layer is set to be 4mm, the heat conductivity coefficient of the heat insulation layer is 0.15W/m.K, and the heat insulation layer 124 can effectively prevent heat from being transferred to the surrounding battery blocks 101, so that the battery thermal runaway is prevented from spreading to other battery blocks 101 to a certain extent. Fig. 8 shows a graph of a thermal spread temperature of a battery module using a 2mm mica sheet layer. Referring to fig. 8, the thickness of the mica sheet is set to 2mm, and when thermal runaway occurs in the battery block 101 No. 1 (cell 1), a great amount of heat is released by redox reaction of positive and negative electrode materials of the battery block 101, and the maximum temperature reaches about 800 ℃ in about 10 seconds. The thermal runaway cell block 101 generates a large amount of heat, most of the heat is dissipated through the bottom liquid cooling plate 103, some of the heat is taken away from the first side liquid cooling plate 104 and the second side liquid cooling plate 105, and part of the heat is blocked by the mica sheet layer. But heat is also conducted to the No. 2 battery block 101 (cell 2) through the parallel bus 102, causing the No. 2 battery block 101 to thermally runaway at 160 seconds, reaching a maximum temperature of 795.4 ℃. This indicates that the use of the 2mm mica sheet layer does not effectively inhibit the thermal runaway of the cell block 101 from spreading to the adjacent cell block 101, although no thermal runaway occurs in the No. 3 to No. 8 cell blocks 101.

Fig. 9 shows a graph of the thermal spread temperature of a battery module using a 4mm mica sheet layer. Referring to fig. 9, for the above case, the thickness of the mica sheet layer is increased to 4mm to improve the heat insulation performance. When the thermal runaway of the No. 1 battery block 101 occurs, a great amount of heat is released by the redox reaction of the anode and cathode materials of the battery block 101, the maximum temperature is about 900 ℃ after about 10 seconds, although a small amount of heat is transferred to the anode and cathode of the No. 2 battery block 101 through the bus bar 102, most of the heat is dissipated through the bottom liquid cooling plate 103 and the first and second side liquid cooling plates 104 and 105, and meanwhile, the heat is transferred from the adjacent battery block 101 to the adjacent battery block 101 by the heat insulation of the 4mm mica sheet layer, so that the heat transfer from the heat runaway battery block 101 to the adjacent battery block 101 can be greatly inhibited. Within 600 seconds of thermal runaway of the No. 1 battery, the maximum heat dissipation power of the bottom liquid cooling plate 103 is 2800W, the maximum heat dissipation power of a single liquid cooling plate on the side surface is 1800W, the heat dissipation power of the double-side liquid cooling reaches 3600W, and then the heat dissipation power gradually decreases. Under the heat dissipation effect of the bottom liquid cooling plate 103, the first side liquid cooling plate 104 and the second side liquid cooling plate 105 and the heat insulation synergistic effect of the mica sheet layer, the cell temperature of the No. 2 battery block 101 reaches 100 ℃ at most, the maximum temperature of the tab of the No. 2 battery block 101 reaches 268 ℃ at most, and the temperature does not reach the triggering heat loss control temperature, so that the mica sheet layer with the thickness of 4mm can effectively inhibit the thermal runaway of the No. 1 battery block 101 from spreading to the adjacent battery block 101.

Fig. 10 shows a graph of the thermal spread temperature of a battery module employing a 2mm mica sheet layer and having only bottom surface liquid cooling. In contrast, in the case of the side panels without liquid-cooled panels, i.e. only the bottom liquid-cooled panel 103, the insulating mica sheet layer is 2mm thick. Referring to fig. 10, the battery block 101 of No. 1 is the first battery block 101, and after several seconds, the thermal runaway of the battery block 101 of No. 1 is completed, and all heat is released. The maximum temperature of the No. 1 battery block 101 reaches 796 ℃, a large amount of heat is taken away through the bottom liquid cooling plate 103, part of the heat is blocked by the heat insulation material, but part of the heat is transferred to the No. 2 battery block 101 through the bus bar 102, and thermal runaway of the No. 2 battery block 101 occurs in 93 s. The thermal runaway of the No. 3 battery occurs at 195s, and the battery sequentially spreads to other adjacent battery blocks 101. Finally, thermal runaway occurs in No. 8 battery block 101 at 539 s. The test shows that thermal runaway propagation of the battery block 101 module cannot be isolated under the condition of no side liquid cooling.

Preferably, a PI-packaged heating film is applied on the large face of the battery block 101. The heating film is slightly smaller than the battery surface (50-90% of the area of the large surface) and is used for rapidly heating the battery block 101 to a proper temperature of 0-10 degrees above zero in cold weather, so that the capacity attenuation and performance reduction of the battery module caused by the cold weather can be avoided.

The utility model provides a pair of battery module thermal runaway protector has following advantage:

1. the first side surface liquid cooling plate and the second side surface liquid cooling plate are used for strengthening heat dissipation, so that the thermal protection capability of the battery module is greatly improved, and the thermal runaway spreading rate and the occurrence probability are reduced; through the mode of arranging of the side runner that from top to bottom width reduces step by step, improve battery upper portion heat-sinking capability to help further reducing battery module upper portion temperature (the highest temperature that corresponds the battery module), reduce the battery upper portion and the lower part difference in temperature, improve battery temperature uniformity and thermal safety performance.

2. The first end plate and the second end plate adopt bending parts with adjustable fastening gaps, so that the first side surface liquid cooling plate and the second side surface liquid cooling plate can be ensured to be tightly connected with the battery without increasing additional stress; through the bolt pilot hole design of end plate and side liquid cooling board to and arrange the insulating layer between the battery piece, can reduce the battery module because of charging, the expansion stress that generates heat and lead to, further improve battery security performance.

3. The cooling liquid is introduced into the first side surface liquid cooling plate and the second side surface liquid cooling plate from the bottom surface liquid cooling plate, so that the integrated design efficiency is improved, and the increase of an additional shunt joint is avoided, so that the whole structure is compact.

It will be apparent to those skilled in the art that various modifications and variations can be made to the above-described exemplary embodiments of the present invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims (10)

1. The utility model provides a battery module thermal runaway protector which characterized in that, battery module includes a plurality of interval arrangement's battery piece, the big face of battery piece is parallel to each other, thermal runaway protector includes:

the bottom liquid cooling plate is arranged at the bottom of the battery module and used for absorbing heat generated at the bottom of the battery module;

the first side surface liquid cooling plate and the second side surface liquid cooling plate are oppositely arranged on two sides of the length direction of the battery module, fixed on the bottom surface liquid cooling plate and used for absorbing heat generated on two sides of the battery module;

the first end plate and the second end plate are oppositely arranged on two sides of the battery module in the width direction, and two sides of the first end plate and the second end plate are respectively fixed on the first side surface liquid cooling plate and the second side surface liquid cooling plate;

the bottom surface liquid cooling plate, the first side surface liquid cooling plate, the second side surface liquid cooling plate, the first end plate and the second end plate are encircled to form a cavity for containing the battery module, and liquid cooling passages which are mutually communicated are arranged in the bottom surface liquid cooling plate, the first side surface liquid cooling plate and the second side surface liquid cooling plate and are used for introducing cooling liquid.

2. The battery module thermal runaway protector of claim 1, wherein an insulating gasket is provided between the battery module and the bottom surface liquid cooling plate.

3. The battery module thermal runaway protector of claim 1, wherein a thermal insulation layer is disposed between the major faces of adjacent battery blocks, the thermal insulation layer conforms to the major faces of the battery blocks, and the thermal insulation layer is made of an ultra low thermal conductivity material.

4. The battery module thermal runaway protector of claim 3, wherein the thermal insulation layer is a mica sheet layer or a composite layer of a mica sheet layer and an aerogel layer.

5. The battery module thermal runaway protector of claim 4, wherein the thickness of the thermal insulation layer is 3.5-4.5 mm.

6. The battery module thermal runaway protector as recited in claim 1, wherein two sides of the first and second end plates are bent outward to form bent portions, wherein first assembly holes are formed in two sides of the first and second side liquid cooling plates, the bent portions are provided with second assembly holes, the bent portions are fixed to the first and second side liquid cooling plates by bolts, and the bolts are screwed into the first and second assembly holes.

7. The battery module thermal runaway protector of claim 6, wherein the bend angle of the bend is 95-120 °.

8. The battery module thermal runaway protector of claim 1, wherein a first inlet pipe, an outlet flow-dividing pipe, a first outlet pipe and an inlet flow-dividing pipe are arranged on the bottom liquid cooling plate;

and a second liquid inlet pipe and a second liquid outlet pipe are arranged on the first side surface liquid cooling plate and the second side surface liquid cooling plate, the liquid outlet flow dividing pipe is communicated with the second liquid inlet pipe, and the liquid inlet flow dividing pipe is communicated with the second liquid outlet pipe.

9. The battery module thermal runaway guard of claim 8, wherein the liquid cooling pathway comprises a first static pressure chamber, a second static pressure chamber, a main flow passage, and a side flow passage;

two first static pressure chambers are arranged on two sides of the bottom surface liquid cooling plate in the length direction, a plurality of main flow channels communicated with the two first static pressure chambers are arranged on the bottom surface liquid cooling plate, the first liquid inlet pipe and the liquid outlet flow dividing pipe are arranged on one first static pressure chamber, and the first liquid outlet pipe and the liquid inlet flow dividing pipe are arranged on the other first static pressure chamber;

the first side surface and the second side surface of the liquid cooling plate are respectively provided with a first static pressure chamber and a second static pressure chamber, the first side surface and the second side surface of the liquid cooling plate are respectively provided with a plurality of side flow channels communicated with the first static pressure chambers, the first liquid inlet pipe is arranged on one first static pressure chamber, and the second liquid outlet pipe is arranged on the other second static pressure chamber.

10. The battery module thermal runaway protector of claim 9, wherein the flow channel axis of the side flow channel forms an included angle of 20-45 degrees with the surfaces of the first and second side liquid cooling plates.

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