Soft package battery module unit and battery module

Abstract

According to the soft package battery module unit and the battery module, the heat exchange device is arranged on the outer wall of the shell of the soft package battery module unit, so that the temperature of the environment where the soft package battery module unit is located is adjusted. The heat exchange comprises cooling and heating, and after at least one of cooling and heating functions is provided, the soft package battery module unit can be heated in a low-temperature environment, so that the charging power of the soft package battery module unit is improved, and the charging speed is improved; in a high-temperature environment, in order to avoid charging frequency reduction of the soft package battery module units, the ambient temperature is reduced, so that the charging speed is increased. Therefore, even if the heat exchange device has one of a heating function and a cooling function, the charging speed of the soft package battery module unit can be improved, so that the charging experience of a user of the electric vehicle carrying the soft package battery module unit is improved.

Description

Technical Field

[0001] This application relates to the field of lithium-ion battery technology, and in particular to a soft-pack battery module unit and battery module. Background Technology

[0002] Currently, pouch batteries are increasingly widely used in daily life and industry. They are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars. As the application areas of pouch batteries continue to expand, the market demand is also increasing. However, the increasing diversity of regions and climates presents many challenges to the performance of pouch batteries. In electric vehicles equipped with pouch batteries, fast charging performance is one of the important factors affecting user experience, but the fast charging performance of pouch batteries is affected by the ambient temperature. As electric vehicles equipped with pouch batteries enter markets in different regions and climates, the problem of excessively high or low temperatures reducing the charging speed of pouch batteries cannot be ignored. Utility Model Content

[0003] This application provides a pouch battery module unit and a battery module to at least solve the technical problem of slow charging speed in existing pouch batteries.

[0004] An embodiment of the first aspect of this application provides a pouch battery module unit, comprising:

[0005] A housing having a placement cavity and a mounting port communicating with the placement cavity;

[0006] A battery cell, the battery cell including tabs, the battery cell being disposed in the placement cavity, the tabs extending out of the housing through the mounting port;

[0007] A heat exchange device is disposed on the outer wall of the shell.

[0008] The soft-pack battery module unit according to the embodiments of this application has at least the following beneficial effects:

[0009] The pouch battery module unit of this application embodiment regulates the temperature of the environment in which the pouch battery module unit is located by providing a heat exchange device on the outer wall of the pouch battery module unit's housing. The heat exchange includes cooling and heating. Having at least one of the functions of cooling and heating, in a low-temperature environment, the pouch battery module unit can be heated, thereby increasing its charging power and thus improving the charging speed; in a high-temperature environment, to prevent the pouch battery module unit from slashing its charging frequency, the ambient temperature is lowered, thereby improving the charging speed. Therefore, even if the heat exchange device only has one function of heating or cooling, it can still improve the charging speed of the pouch battery module unit, thereby enhancing the charging experience for electric vehicle users equipped with it.

[0010] In one possible implementation, the heat exchange device includes a heating film. By providing the heating film, the pouch battery module unit can be heated in a cold environment to increase its temperature, thereby maintaining it at a suitable temperature and improving its charging speed.

[0011] In one possible implementation, the outer wall of the housing includes a front wall and a rear wall opposite each other along its thickness direction, a top wall and a bottom wall opposite each other, a left wall and a right wall opposite each other, the electrode tab is disposed on the top wall, and the heating film is disposed on at least one of the left wall and the right wall.

[0012] In one possible implementation, the length and width of the heating film do not exceed the length and width of the left wall and the right wall, so as to avoid overheating of the heating film of adjacent soft-pack battery module units.

[0013] In one possible implementation, along the direction from the bottom wall to the top wall or from the top wall to the bottom wall, at the left or right wall, the housing extends beyond the heating film by a length L, where L ranges from 1 mm to 5 mm. Setting L to a range of 1 to 5 mm helps to balance heat concentration and the heating effect inside the pouch battery module unit.

[0014] In one possible implementation, the thickness of the heating film is D, which ranges from 0.1 mm to 0.5 mm. Setting the thickness of the heating film to 0.1 mm to 0.5 mm helps to balance heating efficiency and heating film cost.

[0015] In one possible implementation, the heat exchange device further includes a cooling film. This serves two purposes: first, to address the issue of high internal temperatures in the pouch battery module unit due to high ambient temperatures; and second, to prevent overheating and reduced charging power in the pouch battery module unit during rapid charging, as the unit itself generates its own heat.

[0016] In one possible implementation, the outer wall of the housing includes a front wall and a rear wall opposite to each other along its thickness direction, a top wall and a bottom wall opposite to each other, and a left wall and a right wall opposite to each other. The soft-pack battery module unit also includes an explosion-proof valve, which is disposed at one end of the placement cavity near the bottom wall. The cooling film is disposed at least on the top wall, and the length and width of the cooling film do not exceed the length and width of the top wall, which can, to a certain extent, prevent the explosion-proof valve from failing to open the top wall in time.

[0017] In one possible implementation, along the direction from the left wall to the right wall and from the right wall to the left wall, at the top wall, the length of the housing extending beyond the cooling film is W, where W ranges from 1 mm to 5 mm. Setting W within the range of 1 mm to 5 mm helps to balance the safety and cooling effect of the pouch battery module unit.

[0018] An embodiment of the second aspect of this application provides a battery module including a group of pouch battery module units from any of the foregoing embodiments.

[0019] The battery module according to the embodiments of this application has at least the following beneficial effects:

[0020] By incorporating a pouch battery module unit with a heat exchange device, the charging speed of the battery module can be improved, thereby enhancing the charging experience for electric vehicle users. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of a soft-pack battery module unit provided in an embodiment of this application;

[0023] Figure 2 This is a cross-sectional schematic diagram of a soft-pack battery module unit provided in an embodiment of this application;

[0024] Figure 3 This is a side view of a soft-pack battery module unit provided in an embodiment of this application;

[0025] Figure 4 yes Figure 3 A partial schematic diagram of point A in the middle;

[0026] Figure 5 This is a top view of a soft-pack battery module unit provided in an embodiment of this application;

[0027] Figure 6 yes Figure 5 A partial schematic diagram at point B in the middle.

[0028] Figure label:

[0029] Shell-100, placement cavity-110, mounting port-120, outer wall-130, front wall-131, rear wall-132, top wall-133, bottom wall-134, left wall-135, right wall-136;

[0030] Battery cell-200, tab-210;

[0031] Heat exchanger-300, heating film-310, cooling film-320;

[0032] Explosion-proof valve-400. Detailed Implementation

[0033] The embodiments of this implementation are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this implementation, and should not be construed as limiting this implementation.

[0034] In the description of this embodiment, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this embodiment and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this embodiment.

[0035] In the description of this embodiment, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0036] In the description of this embodiment, unless otherwise explicitly limited, terms such as setting, installing, and connecting should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this embodiment in conjunction with the specific content of the technical solution.

[0037] Currently, electric vehicles and other transportation tools equipped with pouch battery modules are becoming increasingly common. As more and more users are involved with electric vehicles, the user experience is receiving increasing attention. Among these user experiences, charging speed is a crucial factor. Traditional gasoline vehicles extend their driving range by refueling, which is quick and convenient due to the abundance of gas stations. However, electric vehicles typically require about an hour to fully charge, making charging experience a significant factor influencing their development. With technological advancements, major electric vehicle manufacturers have introduced the concept of "fast charging" to reduce user waiting time for their vehicles to recharge.

[0038] Charging power is one of the indicators for measuring the charging speed of electric vehicles. The charging speed of an electric vehicle is largely affected by the charging power of its pouch battery module. The higher the charging power of the pouch battery module, the faster the charging speed and the shorter the time to fully charge. Among the many factors affecting the charging power of the pouch battery module, the ambient temperature is one of the most significant. As electric vehicles are sold in various regions and climates, the impact of temperature in the area where the vehicle is used on the charging speed of the pouch battery module is becoming increasingly important. Generally, the ambient temperature required for pouch battery modules to achieve fast charging power is 5-10℃. However, in higher latitude regions, especially in winter, the ambient temperature is generally below 0℃, which significantly impacts the fast charging capability of the pouch battery module. In some tropical or summery regions, high temperatures can cause the pouch battery module to reduce its charging power, thus affecting the charging speed.

[0039] The pouch battery module unit has a modular shape and is a battery technology that uses flexible materials to make the shell. It is a type of liquid lithium-ion battery. Its obvious difference from cylindrical batteries is the flexible shell. By connecting multiple pouch battery module units in parallel to form a battery module, the flexible shell has obvious advantages in terms of venting, etc., making it less likely to explode and safer.

[0040] This application provides a pouch battery module unit that can mitigate the negative impact of ambient temperature on charging rate. For example... Figure 1As shown, the pouch battery module unit includes a housing 100, a battery cell 200, and a heat exchange device 300, which is disposed on the outer wall 130 of the housing 100. The heat exchange device 300 is a device capable of heat exchange. By disposing of the heat exchange device 300 on the outer wall 130 of the housing 100 of the pouch battery module unit, the temperature of the environment in which the pouch battery module unit is located is regulated. Heat exchange includes cooling and heating. Having at least one of the functions of cooling and heating, in a low-temperature environment, the pouch battery module unit can be heated, thereby increasing the charging power of the pouch battery module unit and improving the charging speed; in a high-temperature environment, to prevent the pouch battery module unit from slashing its charging frequency, the ambient temperature is lowered, thereby improving the charging speed. Therefore, even if the heat exchange device 300 only has one function of heating or cooling, it can still improve the charging speed of the pouch battery module unit, thereby improving the charging experience for users of electric vehicles equipped with it.

[0041] like Figure 2 As shown, the housing 100 of the pouch battery module unit has a placement cavity 110 and a mounting port 120 communicating with the placement cavity 110. The battery cell 200 is disposed in the placement cavity 110 of the housing 100. The battery cell 200 includes tabs 210, alternating layers of positive electrode plates, separators, and negative electrode plates. The tabs 210 include positive and negative tabs. The positive and negative electrode plates extend out of the housing 100 through the mounting port 120, respectively, to serve as charging and discharging contact points.

[0042] Understandably, the housing 100 of the pouch battery module unit can be made of aluminum-plastic film to provide protection and support for the battery. The aluminum-plastic film generally consists of three layers: the outermost outer barrier layer (nylon or PET layer), which primarily provides impact resistance, heat resistance, abrasion resistance, and insulation, protecting the battery from environmental damage; the middle barrier layer, which mainly provides waterproofing, moisture resistance, and air isolation, preventing the internal electrolyte from reacting with the external environment, thereby extending the battery's lifespan; and the innermost inner layer, which effectively prevents the internal electrolyte from contacting the aluminum foil layer, avoiding corrosion of the aluminum foil layer, and providing heat-sealing performance to ensure the airtightness of the battery housing 100.

[0043] It can be understood that the positive electrode can be an aluminum foil coated with a positive electrode material, such as lithium cobalt oxide, lithium manganese oxide, and lithium iron phosphate. The negative electrode can be a copper foil coated with a negative electrode material, such as graphite, silicon, and other carbon-based materials.

[0044] Understandably, the pouch battery module unit also includes an electrolyte. After the cell 200 is installed into the placement cavity 110 of the housing 100, an electrolyte needs to be injected into the housing 100. After the electrolyte injection is completed, the housing 100 is sealed. The sealing process is set as required.

[0045] Furthermore, the heat exchange device 300 also includes a heating film 310. By providing the heating film 310, the pouch battery module unit can be heated in a cold environment to increase its temperature, thus maintaining it at a suitable temperature and improving its charging speed. In low-temperature environments, the rate of chemical reactions inside the battery decreases significantly, and the rate at which ions migrate between the positive and negative electrodes slows down, leading to increased internal resistance and affecting the battery's charging and discharging speed. Specifically, when the battery temperature decreases, the viscosity of the electrolyte increases, hindering ion migration and limiting the battery's normal operation.

[0046] Furthermore, the heating film 310 is in the form of a thin sheet, meaning that the length and width of the heating film 310 are much greater than its thickness. It can be understood that the shape of the heating film 310 can be designed according to the shape of the soft-pack battery module unit. Furthermore, the heating film 310 is attached to the outer wall 130 of the housing 100 using adhesive.

[0047] It is understood that the heating film 310 can be a silicone heating film, a polyimide (PI) heating film, an epoxy board heating film, a PET heating film, or an aluminum foil heating film, etc. The heating film 310 has the advantages of large-area uniform heating and energy saving and environmental protection, enabling it to uniformly raise the temperature of the electrolyte inside the soft-pack battery module unit. It can also simultaneously and uniformly reduce the viscosity of the electrolyte in different parts, thereby increasing the ion migration rate inside the soft-pack battery module unit and improving the charging speed.

[0048] Furthermore, the heat exchange device 300 also includes a wire connected to the heating film 310, the wire being used to supply power to the heating film 310.

[0049] Furthermore, such as Figure 3 and Figure 4As shown, the outer wall 130 of the housing 100 includes a front wall 131 and a rear wall 132 opposite to each other along the rearward direction of the housing 100, a top wall 134 opposite to each other, a left wall 135 and a right wall 136 opposite to each other, an electrode tab 210 is disposed on the top wall 133, and a heating film 310 is disposed on at least one of the left wall 135 and the right wall 136, and the projection of the heating film 310 in the direction from the left wall 135 to the right wall 136 lies within the projection of the left wall 135 or the right wall 136 in the direction from the left wall 135 to the right wall 136. Generally speaking, the heating effect of the heating film 310 is directly proportional to its area; the larger the area of ​​the heating film 310, the better the heating effect. The front wall 131 and rear wall 132 of the pouch battery module unit are often much larger than the left wall 135, right wall 136, top wall 133, and bottom wall 134. If the area of ​​the heating film 310 were made the same as the front wall 131 or rear wall 132, the temperature increase would certainly be optimal. However, from a cost and performance perspective, a heating film 310 as large as the front wall 131 is unnecessary. Experiments have shown that a heating film 310 with an area approximately the same as the left wall 135 or right wall 136 is sufficient to achieve the desired temperature increase. Therefore, considering both cost and performance, the area of ​​the heating film 310 does not need to be as large as the front wall 131 or rear wall 132. The second point concerns the placement of the heating film 310 on the left wall 135 or the right wall 136. This is because if the heating film 310, which has a much smaller area than the front wall 131, is attached to the front wall 131, after the pouch battery module units are connected in parallel to form a battery pack, the front wall 131 of the previous pouch battery module unit will come into contact with the rear wall 132 of the next pouch battery module unit. Since the heating film 310 is attached to the front wall 131 and the rear wall 132, there will be a relatively large gap between the front wall 131 and the rear wall 132. During the transportation of the battery pack, the gap will cause the two pouch battery module units to shake easily, affecting the stability of the battery pack.

[0050] Furthermore, at the left wall 135 or right wall 136, along the direction from the bottom wall 134 to the top wall 133 or from the top wall 133 to the bottom wall 134, the housing 100 extends beyond the heating film 310, meaning there is a gap between the heating film 310 and the top wall 133 or bottom wall 134. The length and width of the heating film 310 do not exceed the length and width of the left wall 135 and the right wall 136. After the pouch battery module units are subsequently connected in parallel to form a battery pack, the right wall 136 of the left pouch battery module unit and the left wall 135 of the right pouch battery module unit abut against each other. If the heating film 310 is directly aligned with the top wall 133 or bottom wall 134, the heating films 310 of the two adjacent left and right pouch battery module units will be relatively concentrated, causing overheating at the contact point, which will negatively affect the charging performance of the pouch battery module units.

[0051] Furthermore, such as Figure 4As shown, along the direction from the bottom wall 134 to the top wall 133 or from the top wall 133 to the bottom wall 134, at the left wall 135 or right wall 136, the length of the housing 100 extending beyond the heating film 310 is L. The range of L is 1mm to 5mm, for example, it can be 1mm, 2mm, 3mm, 4mm and 5mm, and there is no specific limitation. If L is too small, it may cause heat concentration and overheating; if L is too large, it may reduce the heating effect of the heating film 310 and fail to raise the temperature inside the soft-pack battery module unit to the expected value in time. Therefore, setting the range of L to 1 to 5mm helps to balance heat concentration and the heating effect inside the soft-pack battery module unit.

[0052] Furthermore, such as Figure 5 and Figure 6 The thickness of the heating film 310 is D, which ranges from 0.1mm to 0.5mm, for example, it can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, and 0.5mm, with no specific limitation. If the thickness of the heating film 310 is less than 0.1mm, the heat generated by the heating film 310 is insufficient; if the thickness of the heating film 310 is greater than 0.5mm, the heat generated by the heating film 310 is excessive, and the cost is high. By setting the thickness of the heating film 310 to 0.1mm to 0.5mm, it is beneficial to balance heating efficiency and the cost of the heating film 310.

[0053] Furthermore, the heat exchange device 300 also includes a cooling film 320. The heating film 310 addresses the problem of low charging rate of the pouch battery module unit due to excessively low temperature. The cooling film 320 addresses two issues: first, the problem of high internal temperature of the pouch battery module unit due to high ambient temperature; and second, the problem of overheating and reduced charging power caused by the pouch battery module unit itself generating heat during fast charging.

[0054] It is understandable that the cooling film 320 can be an active cooling film (requiring a power supply) or a passive cooling film. Active cooling films include, for example, semiconductor cooling films; passive cooling films include, for example, liquid cooling films.

[0055] Furthermore, such as Figure 3As shown, the cooling film 320 is disposed at least once on the top wall 133 and the bottom wall 134. For example, the cooling film 320 can be disposed solely on the top wall 133, solely on the bottom wall 134, or simultaneously on both the top wall 133 and the bottom wall 134. This is because, through practical research, it has been found that the heat generated during charging of the pouch battery module is primarily concentrated at the top and bottom of the housing 100, with less heat generated around the perimeter. Furthermore, the areas of the top wall 133 and the bottom wall 134 are much smaller than those of the front wall 131 and the rear wall 132. Similar to the principle of the heating film 310 being disposed on the left wall 135, disposing of the cooling film 320 on at least one of the top wall 133 and the bottom wall 134 helps to balance cost and the swaying of individual pouch battery module units within the battery pack.

[0056] Furthermore, such as Figure 2 As shown, the soft-pack battery module unit also includes an explosion-proof valve 400, which is located at one end of the placement cavity 110 near the top wall 133. A cooling film 320 is at least located on the top wall 133, extending from the left wall 135 to the right wall 136 and from the right wall 136 to the left wall 135. The housing 100 extends beyond the cooling film 320, meaning the length and width of the cooling film 320 do not exceed the length and width of the top wall 133. Since the top wall 133 corresponds to the explosion-proof valve 400, when the explosion-proof valve 400 is activated, it will push open the top wall 133. At the top wall 133, a certain gap is left between the cooling film 320 and the left and right edges of the top wall 133 to prevent the explosion-proof valve 400 from hindering its normal function.

[0057] Furthermore, such as Figure 6 As described above, along the direction from the left wall 135 to the right wall 136 and from the right wall 136 to the left wall 135, at the top wall 133, the length of the housing 100 extending beyond the cooling film 320 is W. The range of W is 1mm to 5mm, for example, it can be 1mm, 2mm, 3mm, 4mm, and 5mm, with no specific limitation. If W is too small, i.e., the gap between the cooling film 320 and the edge of the top wall 133 is small, the cooling film 320 will prevent the explosion-proof valve 400 from opening the top wall 133 when it is about to activate, affecting the safety of the soft-pack battery module unit. If W is too large, it will result in a large gap between the cooling film 320 and the edge of the top wall 133, making the effect of reducing the internal temperature of the soft-pack battery module unit insignificant. Setting W within the range of 1mm to 5mm helps to balance the safety and cooling effect of the soft-pack battery module unit.

[0058] A second aspect of this application provides a battery module comprising a group of pouch battery module units from any of the foregoing embodiments.

[0059] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this implementation. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] Although embodiments of this implementation have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this implementation, the scope of which is defined by the claims and their equivalents.

Claims

1. A soft-pack battery module unit, characterized in that, include: A housing (100) having a placement cavity (110) and a mounting port (120) communicating with the placement cavity (110); A battery cell (200) includes a tab (210), the battery cell (200) is disposed in the placement cavity (110), and the tab (210) extends out of the housing (100) through the mounting port (120); A heat exchange device (300) is disposed on the outer wall (130) of the housing (100).

2. The soft-pack battery module unit according to claim 1, characterized in that, The heat exchange device (300) includes a heating film (310).

3. The soft-pack battery module unit according to claim 2, characterized in that, The outer wall (130) of the housing (100) includes a front wall (131) and a rear wall (132) opposite to each other along its thickness direction, a top wall (133) and a bottom wall (134) opposite to each other, and a left wall (135) and a right wall (136) opposite to each other. The electrode (210) is disposed on the top wall (133), and the heating film (310) is disposed on at least one of the left wall (135) and the right wall (136).

4. The soft-pack battery module unit according to claim 3, characterized in that, The length and width of the heating film (310) do not exceed the length and width of the left wall (135) and the right wall (136).

5. The soft-pack battery module unit according to claim 3, characterized in that, Along the direction from the bottom wall (134) to the top wall (133) or from the top wall (133) to the bottom wall (134), at the left wall (135) or right wall (136), the length of the housing (100) extending beyond the heating film (310) is L, where L ranges from 1 mm to 5 mm.

6. The soft-pack battery module unit according to claim 2, wherein the thickness of the heating film (310) is D, and the range of D is 0.1 mm to 0.5 mm.

7. The soft-pack battery module unit according to any one of claims 1-6, characterized in that, The heat exchange device (300) also includes a cooling film (320).

8. The soft-pack battery module unit according to claim 7, characterized in that, The outer wall (130) of the housing (100) includes a front wall (131) and a rear wall (132) opposite to each other along its thickness direction, a top wall (133) and a bottom wall (134) opposite to each other, and a left wall (135) and a right wall (136) opposite to each other. The soft-pack battery module unit also includes an explosion-proof valve (400), which is disposed at one end of the placement cavity (110) near the top wall (133). The cooling film (320) is disposed at least on the top wall (133), and the length and width of the cooling film (320) do not exceed the length and width of the top wall (133).

9. The soft-pack battery module unit according to claim 8, characterized in that, Along the direction from the left wall (135) to the right wall (136) and from the right wall (136) to the left wall (135), at the top wall (133), the length of the housing (100) extending beyond the cooling film (320) is W, where W ranges from 1 mm to 5 mm.

10. A battery module, characterized in that, Includes the soft-pack battery module unit as described in any one of claims 1-9.

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