Low-temperature heating battery module structure

Abstract

The utility model discloses a low-temperature heating battery module structure, which comprises a battery module and a protective plate arranged on the surface of the battery module, a first electric heating film is arranged on the surface, contacted with the protective plate, of the battery module, and a second electric heating film is arranged on the surface, not contacted with the protective plate, of the battery module. The low-temperature heating battery module structure disclosed by the utility model has the characteristics of good heating uniformity, high heating efficiency and convenience in operation.

Description

Technical Field

[0001] The utility model relates to the technical field of secondary batteries, in particular to a battery module structure with low-temperature heating. Background Technique

[0002] Temperature has an important impact on the performance of secondary batteries. Taking the low-temperature performance of lithium-ion batteries as an example, the low-temperature environment has a profound impact on the performance of lithium-ion batteries and is reflected in many aspects, including the energy density, charge-discharge efficiency, cycle life, and overall safety performance of the battery, etc. Specifically, it includes:

[0003] For example, the electro-chemical reaction kinetics will slow down: Under low-temperature conditions, the electro-chemical reaction rate of lithium-ion batteries usually slows down. This is because the chemical reactions inside the battery are affected by temperature, and low temperature leads to a decrease in the diffusion rate and reaction rate of ions, thereby reducing the power density of the battery. Ion migration: The migration speed of lithium ions in the electrolyte will slow down, affecting their effective movement between the positive and negative electrodes. The viscosity of the electrolyte increases: Low temperature will cause the viscosity of the electrolyte to increase, further hindering the flow of ions.

[0004] For example, the internal resistance will increase: In a low-temperature environment, the internal resistance of lithium-ion batteries generally increases, mainly due to the decrease in the conduction ability of electrons and ions in the battery. The following factors will all cause an increase in internal resistance. At the same time, the rate of the electrode reaction decreases, and the reaction between the anode and cathode materials and the electrolyte slows down, resulting in energy loss. In addition, it will also affect the solid electrolyte interface (SEI) film. At low temperature, the SEI film of the battery may become more stable and difficult to reconstruct, thereby increasing the impedance.

[0005] For example, the energy and power output will decrease: Due to the changes in the reaction rate and internal resistance, the energy and power output of lithium-ion batteries will be significantly reduced at low temperature. At the same time, the discharge capacity decreases. At low temperature, the effective capacity of the battery may be greatly reduced. For example, the capacity of some batteries at -20°C may only reach 40%-60% of that at room temperature. In addition, the charging process becomes slow, and the charging efficiency of the battery at low temperature decreases significantly, the charging time is long, and it may cause the battery to not be fully charged.

[0006] For example, in terms of the cycle life, the low-temperature usage conditions may also affect the cycle life of lithium-ion batteries, and it will also cause lithium metal precipitation. During the charging process, lithium metal precipitation may occur under low-temperature conditions, which will lead to an increase in the self-discharge rate of the battery and a shortening of the cycle life. Thus, the performance of the electrode material decays. Long-term operation in a low-temperature environment may lead to a decrease in the structural stability of the electrode material, thereby affecting the cycle performance of the battery.

[0007] In terms of safety hazards, the low-temperature environment may also trigger some safety hazards. For example, the uneven migration of lithium ions. In some cases, the uneven migration of lithium ions may cause some parts of the battery to overheat, thus triggering safety hazards. Another example is battery freezing. At extremely low temperatures, the electrolyte inside the battery may freeze, resulting in a significant decline in electrochemical performance and potentially irreversible damage to the battery.

[0008] In summary, in a low-temperature environment, the performance of secondary batteries such as lithium-ion batteries and sodium-ion batteries will be significantly affected, including aspects such as capacity, power, safety, and service life. Therefore, when designing and applying lithium-ion batteries, it is necessary to fully consider these influencing factors and take effective measures to improve the reliability and performance of the batteries under low-temperature conditions.

[0009] In the design of energy storage battery modules, the impact of low temperature on performance cannot be ignored either. In the existing technology, for the low-temperature heating of battery modules, external heating methods such as air heating and / or liquid heating are mostly used, resulting in uneven heating of the battery modules, slow heating speed, and low efficiency. Summary of the Invention

[0010] The purpose of the present utility model is to provide a battery module structure for low-temperature heating, which has the characteristics of good heating uniformity, high heating efficiency, and convenient operation.

[0011] The present utility model can be realized through the following technical solutions:

[0012] The present utility model discloses a battery module structure for low-temperature heating, including a battery module and a protection board arranged on the surface of the battery module. The battery module is provided with a first electric heating film on the surface in contact with the protection board, and the battery module is provided with a second electric heating film on the surface not in contact with the protection board.

[0013] Further, the first electric heating film is located at the top of the battery module, and the second electric heating film is located at the bottom of the battery module. By respectively arranging the first electric heating film and the second electric heating film on two opposite sides of the battery module, two-way synchronous heating is formed, which not only ensures the heating uniformity but also improves the heating efficiency.

[0014] 3 Further, the first electric heating film and the second electric heating film are arranged on the surface of the battery module by an adhesive method. During the operation, as long as the back glue of the electric heating film is torn off, the electric heating film can be pasted at the corresponding position, simplifying the operation process.

[0015] Further, the first electric heating film and the second electric heating film are carbon fiber electric heating films, self-regulating electric heating films or polymer electric heating films. Different electric heating films have their own characteristics. For example, a carbon fiber electric heating film is a heating film that uses carbon fiber material as a heating element. It has a high thermal conductivity and can quickly heat up, with excellent heating efficiency; it is usually very thin in thickness, can be easily installed, and does not occupy space; moreover, it has good durability and strong anti-aging performance. A polymer electric heating film mainly uses conductive polymers as electrothermal materials. It has good flexibility and processing performance, can cover irregular surfaces; it is light in weight, the installation process is simple, and it will not impose a burden on the structure; moreover, it can be used in a variety of environments and is suitable for electrical equipment occasions. A self-regulating electric heating film is a heating film that automatically adjusts the heating temperature according to the ambient temperature. Its self-control temperature avoids the risk of overheating and can flexibly respond to different environmental conditions; after reaching the set temperature, it will automatically reduce the power and reduce unnecessary energy consumption.

[0016] Further, the areas of the first electric heating film and the second electric heating film are both smaller than the surface of the battery module they are in contact with, ensuring that the first electric heating film and the second electric heating film are fully combined with the contact surface, and ensuring the reliability of their adhesion.

[0017] Further, the first electric heating film and the second electric heating film are both electrically connected to the protection board, and the heating control is carried out by the protection board, combining the low-temperature heating of the battery module in the protection board control to more accurately achieve low-temperature heating.

[0018] Further, the heating temperature range of the first electric heating film and the second electric heating film is 0-10 degrees Celsius, ensuring an appropriate temperature range, energy-saving and environmentally friendly.

[0019] Further, the battery module is a secondary battery with series-parallel grouping, and the secondary battery is a lithium-ion battery or a sodium-ion battery, meeting the usage needs of different types of secondary batteries.

[0020] Further, the lithium-ion battery is a lithium cobalt oxide battery, a lithium manganese oxide battery, a lithium iron phosphate battery or a ternary material battery, meeting the usage needs of different types of lithium-ion batteries.

[0021] Further, the sodium-ion battery is a layered oxide sodium-ion battery, a polyanion-type material sodium-ion battery or a Prussian blue material sodium-ion battery, meeting the usage needs of different types of sodium-ion batteries.

[0022] The battery module structure with low-temperature heating of the present utility model has the following beneficial effects:

[0023] First, the heating uniformity is high. By using the first electric heating film and the second electric heating film to heat the battery module from different sides simultaneously, based on the fact that the temperatures at all positions of the electric heating film are kept consistent, a high heating uniformity is ensured;

[0024] Second, high heating efficiency. By adopting the method of directly contacting the first electric heating film and the second electric heating film with the battery module for heating instead of the external heating method in the prior art, the heat transfer efficiency of solids is much higher than that of air or liquid heat transfer, thus improving the heating efficiency;

[0025] Third, convenient installation. By adopting the first electric heating film and the second electric heating film, the heating film can be directly attached to the surface of the battery module, and the whole operation is very simple and convenient to meet the heating requirements of battery modules with different shapes and structures. Description of the Drawings

[0026] Appendix Figure 1 is a schematic structural diagram of a battery module structure with low-temperature heating according to the present invention;

[0027] The marks in the drawings include: 100, battery module; 200, protection board; 300, first electric heating film; 400, second electric heating film. Detailed Embodiment

[0028] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the products of the present invention will be further described in detail below in conjunction with the embodiments and the drawings.

[0029] As Figure 1 shown, the present invention discloses a battery module structure with low-temperature heating, including a battery module 100 and a protection board 200 arranged on the surface of the battery module 100. A first electric heating film 300 is arranged on the surface of the battery module 100 in contact with the protection board 200, and a second electric heating film 400 is arranged on the surface of the battery module 100 not in contact with the protection board 200. Specifically, the first electric heating film is located at the top of the battery module, and the second electric heating film is located at the bottom of the battery module. For the convenience of operation, the first electric heating film and the second electric heating film are arranged on the surface of the battery module by an adhesive method.

[0030] In the present invention, there is no special requirement for the type of the electric heating film. The first electric heating film and the second electric heating film are carbon fiber electric heating films, self-regulating electric heating films or polymer electric heating films.

[0031] In the present invention, in order to ensure the reliability of adhesion, the areas of the first electric heating film and the second electric heating film are both smaller than the surface of the battery module in contact with them. Of course, in order to meet the convenience of operation at the same time, a tear-off part is convexly arranged on the electric heating film. The tear-off part protrudes from the battery module, which is convenient for operation and observation.

[0032] In the present invention, in order to achieve precise control, the first electric heating film and the second electric heating film are both electrically connected to the protection board, and the heating control is carried out by the protection board.

[0033] Furthermore, the heating temperature range of the first electric heating film and the second electric heating film is 0 - 10 degrees Celsius.

[0034] The structure of the present utility model has good applicability. The battery module is a secondary battery with series and parallel configuration, and the secondary battery is a lithium-ion battery or a sodium-ion battery. Specifically, the lithium-ion battery is a lithium cobalt oxide battery, a lithium manganese oxide battery, a lithium iron phosphate battery, or a ternary material battery; the sodium-ion battery is a layered oxide sodium-ion battery, a polyanion-type material sodium-ion battery, or a prussian blue material sodium-ion battery.

[0035] The principle of the present utility model is as follows:

[0036] 1. Installation: After the aluminum sheets of the battery module are laser welded, after the first heating film and the second electric heating film are peeled off the back glue, they are pasted on both sides of the battery module without exposing the battery module.

[0037] 2. Power connection: One wire of the first electric heating film and the second electric heating film is respectively fixed to the positive electrode of the battery module, and the other wire of the first electric heating film and the second electric heating film is welded to the "heating" position of the protection board.

[0038] 3. Heating control: When the temperature is less than 0°C, the first electric heating film and the second electric heating film start heating, and the battery module triggers low-temperature protection; when the temperature reaches 10°C, the heating functions of the first electric heating film and the second electric heating film are turned off.

[0039] In the description of the present utility model, it should be understood that terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0040] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, "a plurality" means two or more, unless otherwise specifically defined.

[0041] In the present utility model, unless otherwise clearly stipulated and defined, terms such as "installation", "connection", "linkage", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0042] The above embodiments are only specific embodiments of the present utility model, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several deformations and improvements can still be made, and these obvious replacement forms all belong to the protection scope of the present utility model.

Claims

1. A low-temperature heated battery module structure, comprising a battery module and a protective plate arranged on the surface of the battery module, characterized in that: The battery module is provided with a first electric heating film on a surface in contact with the protection plate, and the battery module is provided with a second electric heating film on a surface not in contact with the protection plate.

2. The low temperature heated battery module structure according to claim 1, characterized in that: The first electric heating film is located at the top of the battery module, and the second electric heating film is located at the bottom of the battery module.

3. The low temperature heated battery module structure according to claim 2, characterized in that: The first electric heating film and the second electric heating film are arranged on the surface of the battery module by bonding.

4. The low temperature heated battery module structure according to claim 3, characterized in that: The first electric heating film and the second electric heating film are carbon fiber electric heating films, self-temperature regulating electric heating films or polymer electric heating films.

5. The low temperature heated battery module structure according to claim 4, characterized in that: The areas of the first electric heating film and the second electric heating film are both smaller than the surface of the battery module in contact with them.

6. The low temperature heated battery module structure according to claim 5, characterized in that: The first electric heating film and the second electric heating film are both electrically connected to the protection plate, and heating is controlled by the protection plate.

7. The low temperature heated battery module structure according to claim 6, characterized in that: The heating temperature range of the first electric heating film and the second electric heating film is 0-10 degrees Celsius.

8. The low temperature heated battery module structure according to claim 7, characterized in that: The battery module is a secondary battery connected in series and parallel, and the secondary battery is a lithium-ion battery or a sodium-ion battery.

9. The low temperature heated battery module structure according to claim 8, characterized in that: The lithium-ion battery is a lithium cobalt oxide battery, a lithium manganese oxide battery, a lithium iron phosphate battery or a ternary material battery.

10. The low temperature heated battery module structure according to claim 8, characterized in that: The sodium ion battery is a layered oxide sodium ion battery, a polyanion material sodium ion battery or a Prussian blue material sodium ion battery.

Images