Battery module and battery system

Abstract

The utility model provides a battery module and a battery system. The battery module comprises a battery pack and a heating film, the battery pack comprises a plurality of sodium ion batteries which are arranged along a first direction. And a heating film is clamped between at least two adjacent sodium ion batteries. The plurality of sodium ion batteries are arranged along the first direction, and the heating film is clamped between at least two adjacent sodium ion batteries, so that compared with the traditional method of heating by using a liquid cooling plate, the thermal contact area between the sodium ion batteries and the heating film can be increased, the heat loss of the heating film in the battery heating process is reduced, and the battery heating efficiency is improved. The effective heat exchange between the sodium-ion battery and the heating film is improved, so that the temperature rise efficiency of the sodium-ion battery is improved, and the cold start time of the sodium-ion battery is shortened.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a battery module and a battery system. Background Technology

[0002] In certain situations, especially in cold climates, the starting performance of sodium-ion batteries is more susceptible to adverse effects compared to some other battery types, such as lithium-ion batteries, at low temperatures. This is because sodium ions are less mobile at low temperatures, leading to reduced battery performance. Therefore, to mitigate the potential impact on the starting capability of sodium-ion batteries in cold climates, it is necessary to heat the batteries to improve their performance and reliability. In related technologies, heat exchange is achieved through liquid cooling plates. Typically, the liquid cooling plate is located on the bottom side of a battery pack consisting of multiple individual sodium-ion batteries stacked together. As the coolant flows through the liquid cooling plate, it provides heat to the sodium-ion batteries. The sodium-ion batteries continuously absorb heat from the liquid cooling plate, thus achieving the effect of heating the batteries. However, the heating efficiency in these technologies is not high. Utility Model Content

[0003] The embodiments of this utility model provide a battery module and a battery system that can improve the technical problem of low heating efficiency when heating batteries in related technologies.

[0004] In a first aspect, embodiments of the present invention provide a battery module, comprising:

[0005] A battery pack includes multiple batteries, which are arranged along a first direction.

[0006] A heating film is sandwiched between at least two adjacent batteries.

[0007] In one embodiment, it also includes a power supply, a BMS, and a temperature sensor.

[0008] The power supply is electrically connected to the heating film, the temperature sensor is located on the surface of the battery to monitor the temperature of the battery, and the BMS is electrically connected to the temperature sensor to control the power supply to power on or off the heating film according to the temperature collected by the temperature sensor.

[0009] In one embodiment, a relay is also included, the relay comprising a coil, a conductive element, and two spaced-apart contacts, the coil being connected in series with the BMS, and the two contacts being electrically connected to the power supply and the heating film, respectively, and the BMS controlling the coil to be energized so that the conductive element is electrically connected to the two contacts.

[0010] In one embodiment, a fuse is also included, which is connected in series with the power supply and the heating film.

[0011] In one embodiment, the heating film is a PI heating film.

[0012] In one embodiment, the PI heating film is provided between any two adjacent batteries in the battery pack; and / or,

[0013] Along the length of the battery pack, at least one of the two ends of the battery pack is provided with the PI heating film; and / or,

[0014] Along the width direction of the battery pack, at least one of the two sides of the battery pack is provided with the PI heating film; and / or,

[0015] Along the height direction of the battery pack, the bottom side of the battery pack is provided with the PI heating film.

[0016] In one embodiment, in any two adjacent batteries, each battery includes a mounting surface facing the other battery, and the PI heating film is sandwiched between the mounting surfaces of the batteries, with the edge of the PI heating film and the edge of the mounting surface spaced apart.

[0017] In one embodiment, the distance between the edge of the PI heating film and the edge of the mounting surface is between 3 mm and 4 mm.

[0018] In one embodiment, the thickness of the PI heating film is between 0.35 mm and 0.37 mm.

[0019] Secondly, embodiments of the present invention provide a battery system, comprising:

[0020] casing; and

[0021] The battery module is the battery module described in any embodiment of this application, and the battery module is disposed on the housing.

[0022] The beneficial effects of the embodiments of this utility model are as follows:

[0023] The battery module provided in this embodiment arranges multiple sodium-ion batteries along a first direction, with a heating film sandwiched between at least two adjacent sodium-ion batteries. Compared to the traditional method of heating with a liquid cooling plate, this design increases the thermal contact area between the sodium-ion battery and the heating film, reduces heat loss during the heating process, and improves the effective heat exchange between the sodium-ion battery and the heating film. After the heating film is activated, heating the sodium-ion battery helps to improve the temperature rise efficiency of the sodium-ion battery, effectively increases the internal chemical reaction rate of the sodium-ion battery, thereby enhancing the starting capability of the sodium-ion battery, shortening the cold start time, and improving the charging and discharging efficiency of the sodium-ion battery. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the battery module provided in an embodiment of this utility model;

[0026] Figure 2 This is an exploded view of the battery module provided in an embodiment of this utility model;

[0027] Figure 3 This is a schematic diagram of the assembly of a sodium-ion battery and a heating film provided in an embodiment of this utility model;

[0028] Figure 4 This is a schematic diagram of the heating circuit of the battery module provided in an embodiment of this utility model.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Battery module; x, first direction / length direction; y, width direction; z, height direction;

[0031] 10. Battery pack; 11. Sodium-ion battery; 111. Mounting surface; 20. Heating film;

[0032] 30. Power supply; 40. BMS; 50. Temperature acquisition device; 60. Relay; 61. Coil; 62. Conductive component; 63. Contact; 70. Fuse. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0034] In certain situations, particularly in cold climates, the reduced rate of chemical reactions in a battery makes it difficult to start at low temperatures. The chemical reactions in a battery generate current through the transfer of ions in the electrolyte, and low temperatures slow down these reactions, resulting in a decrease in the battery's ability to output current. Specifically, at low temperatures, the battery electrolyte becomes more viscous, the migration rate of ions slows down, and the rate of chemical reactions decreases. This leads to a slower release rate of stored energy, reducing the battery's ability to output current and making it difficult to start. Furthermore, low temperatures increase the battery's internal resistance, further weakening its output capacity. This increased internal resistance makes it even more difficult for the battery to provide sufficient current to start an engine or supply power to other devices at low temperatures.

[0035] Therefore, at low temperatures, batteries require longer startup times or external heating devices to raise their temperature and increase their output capacity. Sodium-ion batteries, as a novel energy storage technology, are attracting increasing attention and investment. However, among various battery types, the startup performance of sodium-ion batteries is more susceptible to adverse effects at low temperatures compared to traditional batteries such as lithium-ion batteries. This is because sodium ions are less active at low temperatures, leading to reduced battery performance. To mitigate the potential impact on startup capability in cold climates, heating is necessary to improve performance and reliability. One solution to the startup difficulties of sodium-ion batteries in such conditions is to use liquid cooling plates for heat exchange. Typically, these plates are located at the bottom of a battery pack consisting of multiple stacked sodium-ion cells. The coolant flowing through the cooling plate provides heat to the sodium-ion cells, which continuously absorb heat, thus achieving the effect of heating. However, the heating efficiency is not high.

[0036] Please see Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the battery module provided in an embodiment of this application. Figure 2This is an exploded view of a battery module provided in an embodiment of this application. The battery module 1 includes a battery pack 10 and a heating film 20. The battery pack 10 may include multiple sodium-ion batteries 11, which can be arranged along a first direction x. The multiple sodium-ion batteries 11 are connected together in series or parallel to achieve larger capacity, higher voltage, or higher power output. A heating film 20 is sandwiched between at least two adjacent sodium-ion batteries 11. The heating film 20 may have a heating area adapted to the surface of the sodium-ion battery 11. The amount of heat generated by the heating film 20 can be adjusted by controlling the current of the heating film 20. The heating film 20 heats the sodium-ion batteries 11 to improve the performance of the sodium-ion batteries 11 in low-temperature environments, thereby keeping the sodium-ion batteries 11 within a suitable operating temperature range.

[0037] The battery module 1 provided in this embodiment arranges multiple sodium-ion batteries 11 along a first direction x, with a heating film 20 sandwiched between at least two adjacent sodium-ion batteries 11. Compared with the traditional method of heating with a liquid cooling plate, this design can increase the thermal contact area between the sodium-ion battery 11 and the heating film 20, reduce the heat loss of the heating film 20 during the heating of the sodium-ion battery 11, and improve the effective heat exchange between the sodium-ion battery 11 and the heating film 20. After the heating film 20 is activated, heating the sodium-ion battery 11 helps to improve the temperature rise efficiency of the sodium-ion battery 11, effectively improve the chemical reaction rate inside the sodium-ion battery 11, thereby enhancing the starting capability of the sodium-ion battery 11, shortening the cold start time, and improving the charging and discharging efficiency of the sodium-ion battery 11.

[0038] The heating film 20 is a thin film material used to heat the sodium-ion battery 11. It contains conductive material, which generates heat to heat the sodium-ion battery 11 when energized. The heating film 20 can be a PI heating film, a metal conductive heating film, a carbon fiber heating film, a conductive polymer heating film, a thermally conductive film, or a nano-heating film. This embodiment uses a PI heating film as an example for illustrative description; implementation details of other types of heating films can be found in the description of PI heating films in this specification. The thickness of the PI heating film provided in this embodiment can be designed according to the operating environment of the battery module 1 to achieve the desired heating effect. The sodium-ion battery provided in this embodiment can be a square battery, a cylindrical battery, a battery with a customized shape, or a battery with an unconventional shape. This embodiment does not specifically limit the shape of the sodium-ion battery. The length direction x of the sodium-ion battery can be the thickness direction of the sodium-ion battery 11, or the arrangement direction of multiple sodium-ion batteries 11. The width direction y of the sodium-ion battery is a direction perpendicular to its length direction x, and the height direction z is a direction parallel to its gravity. The thickness of the PI heating film can be set between 0.35mm and 0.37mm. A PI heating film can be provided between any two adjacent sodium-ion batteries 11 in the battery pack 10, and / or, along the length direction x of the battery pack 10, at least one end of the battery pack 10 is provided with a PI heating film, and / or, along the width direction y of the battery pack 10, at least one side of the battery pack 10 is provided with a PI heating film, and / or, along the height direction z of the battery pack 10, the bottom side of the battery pack 10 is provided with a PI heating film. This application, by arranging PI heating films at one or more locations in the battery pack 10, has the advantage of achieving uniform heating of the entire battery pack 10, helping to ensure uniform temperature distribution in all parts of the battery pack 10, preventing local overheating or overcooling, and improving the charge and discharge performance of the sodium-ion battery 11. In this embodiment, "and / or" describes the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / ", unless otherwise specified, generally indicates that the preceding and following associated objects have an "or" relationship.

[0039] Please see Figure 3 , Figure 3This is a schematic diagram of the assembly of a sodium-ion battery and a heating film provided in an embodiment of this application. In some embodiments, the designer can place the PI heating film on the surface of the sodium-ion battery 11 that needs to be heated, according to the heating requirements, so as to achieve heating of the corresponding surface of the sodium-ion battery 11, ensuring good heating effect, reasonable energy consumption and uniform temperature distribution. For example, in any two adjacent sodium-ion batteries 11, each sodium-ion battery 11 includes a mounting surface 111 facing the other sodium-ion battery 11. A PI heating film is sandwiched between the mounting surfaces 111 of the sodium-ion batteries 11. The edge of the PI heating film and the edge of the mounting surface 111 are spaced apart. The distance between the edge of the PI heating film and the edge of the mounting surface 111 is between 3mm and 4mm. In some embodiments, the distance Δd between the edge of the PI heating film and the edge of the mounting surface 111 can be set to any value within this range, such as 3mm, 3.25mm, 3.5mm, 3.75mm, or 4mm. This allows for a larger thermal contact area between the PI heating film and the sodium-ion battery 11, increasing the temperature rise rate of the sodium-ion battery 11. At the same time, the preset distance between the PI heating film and the edge of the sodium-ion battery 11 can effectively reduce the safety risks caused by overheating and reduce the production input cost of the product. In some embodiments, the mounting surface 111 of the sodium-ion battery 11 may be bent to some other surfaces of the sodium-ion battery 11. In this embodiment, a curved surface is formed between the mounting surface 111 and other surfaces of the sodium-ion battery 11. In this case, the edge of the mounting surface 111 refers to the intersection line where it intersects with the curved surface.

[0040] Please refer to the figure. Figure 4 , Figure 4This is a schematic diagram of the heating circuit of the battery module provided in this application embodiment. In addition to the battery pack 10 and heating film 20 described above, the battery module 1 may also include a power supply 30, a BMS 40 (Battery Management System), and a temperature sensor 50. The power supply 30 is electrically connected to the heating film 20, providing electrical energy to the heating film 20. The heating film 20 converts the electrical energy provided by the power supply 30 into heat energy that raises the temperature of the sodium-ion battery 11. The temperature sensor 50 can be any suitable type of component, such as a thermistor temperature sensor, a temperature sensor chip, an infrared temperature sensor, or a fiber optic temperature sensor. The temperature sensor 50 is disposed on the surface of the sodium-ion battery 11 to monitor and record the temperature of the sodium-ion battery 11. The temperature sensor 50 is used in conjunction with the battery management system BMS 40. The temperature sensor 50 can convert the acquired data related to the temperature of the sodium-ion battery 11 into electrical signals that can be recognized and processed by the BMS 40. The BMS 40 is a... A system for monitoring, protecting, and managing a battery pack 10 includes a BMS40 that stores a temperature control program. The BMS40 is electrically connected to a temperature sensor 50. After acquiring the temperature of the sodium-ion battery, the BMS40 determines when and how to control the operation of the heating film 20 based on its stored temperature control program. For example, the BMS40 controls the power supply 30 to energize or de-energize the heating film 20 according to the temperature acquired by the temperature sensor 50, ensuring the sodium-ion battery 11 operates stably and continuously within a safe temperature range. This allows the heating film 20 to operate according to the set program. When the temperature of the sodium-ion battery 11 exceeds the safe range, the power supply 30, under the control of the BMS40, can stop charging and discharging the heating film 20 or reduce the charging and discharging current to prevent the heating film 20 from continuously heating and causing the sodium-ion battery 11 to overheat and be damaged. It should be noted that in this embodiment, "connection" can be understood as an electrical connection. The connection between two electrical components can be a direct or indirect connection between the two components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0041] The battery module 1 may also include a relay 60, which includes a coil 61, a conductive element 62, and two spaced-apart contacts 63. The coil 61 is connected in series with the BMS 40, and the two contacts 63 are electrically connected to the power supply 30 and the heating film 20, respectively. The BMS 40 controls the coil 61 to be energized so that the conductive element 62 is electrically connected to the two contacts 63. The relay 60 may also include a bracket, with the coil 61 fixed to the bracket and the conductive element 62 elastically connected to the bracket. The conductive element 62 is made of a magnetic conductive material. When the coil 61 is energized, it can generate a magnetic field, which can cause the conductive element 62 to approach and contact the two contacts 63, thereby establishing an electrical connection between the power supply 30 and the heating film 20. When the coil 61 is de-energized, the magnetic field disappears, the conductive element 62 resets and eventually moves away from the two contacts 63, thereby disconnecting the electrical connection between the power supply 30 and the heating film 20.

[0042] In order to enable the circuit to be quickly cut off when the current in the circuit exceeds the safe range, so as to prevent dangerous situations such as fire and equipment damage caused by overload or short circuit, in some embodiments, the battery module 1 may also include a fuse 70. The fuse 70 is connected in series with the power supply 30 and the heating film 20. When the current in the circuit exceeds the rated value of the fuse 70, the fuse 70 is heated and melted, thereby quickly cutting off the circuit, preventing excessive current from flowing, and protecting the safety of equipment and personnel.

[0043] This application also proposes a battery system, which includes a housing and a battery module 1, wherein the battery module is the battery module 1 of any embodiment of this application, and the battery module 1 is disposed in the housing.

[0044] To help those skilled in the art better understand the implementation methods of the battery module and battery system provided in the embodiments of this application, the following is an illustrative description of the working process of the battery module.

[0045] If the temperature sensor detects that the sodium-ion battery is within the first temperature range, the BMS energizes the relay coil based on the sensed temperature. The relay coil generates a magnetic field, which connects the conductive parts to the contacts. At this time, the power supply and the heating film are electrically connected, and the heating film begins to heat the sodium-ion battery.

[0046] If the temperature sensor detects that the sodium-ion battery is within the second temperature range, the BMS stops energizing the relay coil based on the sensed temperature. The coil's magnetic field disappears, and the conductive parts are disconnected from the contacts. At this time, the power supply and heating film are electrically disconnected, and the heating film stops generating heat to heat the sodium-ion battery.

[0047] The first temperature range is smaller than the second temperature range. For example, in some embodiments, the first temperature range may be a temperature range below 25°C, and the second temperature range may be a temperature range above 30°C.

[0048] For example, when the ambient temperature is below 25°C, a cold start is required for the sodium-ion battery. In this case, the heating film is activated to heat the sodium-ion battery until the sodium-ion battery starts running and the cold start is completed. After that, the heating film power is reduced or the heating film heating is stopped as the temperature of the sodium-ion battery changes.

[0049] After the sodium-ion battery completes its cold start, it enters a normal charge-discharge cycle. Due to the low temperature rise of the sodium-ion battery and insufficient heat generation during its own charge-discharge process, the temperature of the sodium-ion battery may still be below 25°C during operation. When the temperature of the sodium-ion battery is below 25°C, the heating film is activated to heat the sodium-ion battery and bring it back to the suitable temperature range of 30°C-35°C. When the temperature of the sodium-ion battery is above 30°C, the heating film is stopped from continuing to heat the sodium-ion battery.

[0050] Through the above methods, the battery system can adjust the output power and operating status of the heating film in real time according to the temperature changes of the sodium-ion battery during operation, so that the sodium-ion battery is kept within a suitable temperature range.

[0051] In summary, the battery module and battery system provided in this application have at least the following beneficial effects: On the one hand, by arranging multiple sodium-ion batteries along a first direction and sandwiching a heating film between at least two adjacent sodium-ion batteries, the thermal contact area between the sodium-ion batteries and the heating film can be increased, heat loss during the heating process of the heating film can be reduced, and the effective heat exchange between the sodium-ion batteries and the heating film can be improved, thereby improving the temperature rise efficiency of the sodium-ion batteries and shortening the cold start time of the sodium-ion batteries; on the other hand, by using a PI heating film at one or more locations in the battery pack, uniform heating of the entire battery pack can be achieved, which helps to ensure uniform temperature distribution in all parts of the battery pack, prevent local overheating or overcooling, and improve the charge and discharge performance of the sodium-ion batteries.

[0052] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A battery module, characterized in that, include: The battery pack includes multiple sodium-ion batteries, which are arranged along a first direction. A heating film is sandwiched between at least two adjacent batteries, and the heating film is a PI heating film; Wherein, the PI heating film is provided between any two adjacent batteries in the battery pack; and / or, Along the length of the battery pack, at least one of the two ends of the battery pack is provided with the PI heating film; and / or, Along the width direction of the battery pack, at least one of the two sides of the battery pack is provided with the PI heating film; and / or, Along the height direction of the battery pack, the bottom side of the battery pack is provided with the PI heating film.

2. The battery module according to claim 1, characterized in that, It also includes the power supply, BMS, and temperature acquisition unit. The power supply is electrically connected to the heating film, the temperature sensor is located on the surface of the battery to monitor the temperature of the battery, and the BMS is electrically connected to the temperature sensor to control the power supply to power on or off the heating film according to the temperature collected by the temperature sensor.

3. The battery module according to claim 2, characterized in that, It also includes a relay, which includes a coil, a conductive element, and two contacts spaced apart from each other. The coil is connected in series with the BMS, and the two contacts are electrically connected to the power supply and the heating film, respectively. The BMS controls the coil to be energized so that the conductive element is electrically connected to the two contacts.

4. The battery module according to claim 2, characterized in that, It also includes a fuse, which is connected in series with the power supply and the heating film.

5. The battery module according to claim 1, characterized in that, In any two adjacent batteries, each battery includes a mounting surface facing the other battery. The PI heating film is sandwiched between the mounting surfaces of the battery, and the edges of the PI heating film and the edges of the mounting surfaces are spaced apart.

6. The battery module according to claim 5, characterized in that, The distance between the edge of the PI heating film and the edge of the mounting surface is between 3mm and 4mm.

7. The battery module according to claim 1, characterized in that, The thickness of the PI heating film is between 0.35 mm and 0.37 mm.

8. A battery system, characterized in that, include: chassis; as well as A battery module, wherein the battery module is the battery module according to any one of claims 1-7, and the battery module is disposed in the housing.

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