Battery thermal management system based on light-operated driving contact type phase change

Abstract

The invention belongs to the field of battery thermal management, and particularly relates to a battery thermal management system based on light-operated driving contact type phase change. The system comprises a thermochromic phase change material, a liquid storage cavity, a spring, a photosensitive assembly, a liquid flow channel and a light source assembly. One side of the battery is in close contact with one side of the solid-state thermochromic phase change material, the opening side of the liquid storage cavity is tightly attached to the other side of the solid-state thermochromic phase change material, and the liquid storage cavity can move towards the direction close to the solid-state thermochromic phase change material; a plurality of through holes are formed in the top of the liquid storage cavity, and a liquid flow channel for the liquid thermochromic phase change material to flow is formed between the upper surfaces of the liquid storage cavity and the thermochromic phase change material and the inner wall of the battery shell; one end of the spring is connected with one side of the liquid storage cavity opposite to the opening, and the other end is connected with the inner wall of the battery shell; the light source assembly and the photosensitive assembly are located on the side, making contact with the solid-state thermochromic phase change material, of the battery, the light-emitting end of the light source assembly faces the photosensitive end of the photosensitive assembly, and the photosensitive assembly receives light emitted by the light source assembly. The battery is always in contact with the solid-state phase change material, and heat dissipation is continuously performed on the battery in a latent heat form, so that the heat management capability is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power battery thermal management, and particularly relates to a battery thermal management system based on photo-controlled drive contact phase change, which is particularly suitable for power battery thermal management under high-rate charge and discharge conditions. Background Art

[0002] With the wide application of high-energy-density lithium-ion batteries in fields such as electric vehicles and energy storage power stations, the efficiency and reliability of the battery thermal management system have become the core issues restricting its performance and safety. A large amount of heat is generated during the charge and discharge process of the battery. Especially during rapid charging and high-load discharging, the internal temperature of the battery rises rapidly. If the temperature control system cannot dissipate heat in a timely and effective manner, the battery temperature may exceed the safe range, resulting in performance degradation, shortened service life, and even safety accidents. Therefore, how to efficiently manage the battery temperature and keep it within the optimal operating temperature range has become an urgent technical challenge for new energy vehicles and energy storage systems.

[0003] Traditional battery thermal management systems can be divided into various methods such as air cooling, liquid cooling, phase change material cooling, heat pipe cooling, and thermoelectric refrigeration. Phase change material cooling can, to a certain extent, balance the temperature change of the battery by virtue of its characteristic of absorbing or releasing a large amount of latent heat during the phase change process, avoiding the temperature from rising or falling too quickly and achieving the purpose of effective heat dissipation. However, there are still significant defects in the existing phase change material cooling in battery thermal management. Specifically, the solid phase change material in the area near the battery will preferentially absorb heat and undergo a phase change, while the thermal conductivity of the liquid phase change material usually drops significantly (usually below 0.2 W / mK), resulting in a significant reduction in its heat conduction efficiency. Moreover, the liquid phase change material in the area near the battery also hinders the surrounding solid phase change material from absorbing heat, making the heat generated by the battery unable to be conducted out in a timely and effective manner, thereby increasing the risk of local temperature runaway of the battery, especially during high-rate charge and discharge processes, where the rate of heat accumulation exceeds the rate of heat dissipation. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the technical problem to be solved by the present invention is to propose a battery thermal management system based on photo-controlled drive contact phase change.

[0005] The present invention adopts the following technical solutions to solve the above technical problems:

[0006] A battery thermal management system based on photo-controlled drive contact phase change, characterized in that it includes a thermochromic phase change material, a liquid storage cavity, a spring, a photosensitive component, a liquid flow channel, and a light source component;

[0007] One side of the battery is in close contact with one side of the solid-state thermochromic phase-change material, and the open side of the liquid storage cavity is closely attached to the other side of the solid-state thermochromic phase-change material. As the solid-state thermochromic phase-change material gradually transforms into the liquid-state thermochromic phase-change material, the liquid storage cavity can move towards the direction close to the solid-state thermochromic phase-change material. The solid-state thermochromic phase-change material is opaque, while the liquid-state thermochromic phase-change material is translucent. A number of through holes are provided at the top of the liquid storage cavity, and a liquid flow channel is formed between the upper surfaces of the liquid storage cavity and the thermochromic phase-change material and the inner wall of the battery housing. The liquid-state thermochromic phase-change material flows into the liquid storage cavity through the liquid flow channel. One end of the spring is connected to the side of the liquid storage cavity opposite to the opening, and the other end is connected to the inner wall of the battery housing. The light source assembly and the photosensitive assembly are located on the side where the battery is in contact with the solid-state thermochromic phase-change material. The light-emitting end of the light source assembly faces the photosensitive end of the photosensitive assembly. The photosensitive assembly receives the light emitted by the light source assembly and serves as the control signal for the movement of the liquid storage cavity.

[0008] Further, a heat-conducting sheet is provided in the liquid flow channel, and the heat-conducting sheet is in contact with the battery at the same time.

[0009] Further, a copper rod is provided on the open side of the liquid storage cavity; during the process of the liquid storage cavity moving towards the solid-state thermochromic phase-change material, the copper rod is not energized; during the process of the liquid storage cavity resetting, the copper rod is energized.

[0010] Further, a heating sheet is provided on the inner wall of the liquid storage cavity; during the process of the liquid storage cavity resetting, the heating sheet is energized.

[0011] Further, the working process of the system is as follows:

[0012] When the surface temperature of the battery is greater than or equal to the phase-change temperature, the solid-state thermochromic phase-change material in close contact with the battery undergoes a phase change and transforms into the liquid state. The light emitted by the light source assembly penetrates the liquid-state thermochromic phase-change material and is received by the photosensitive assembly. At this time, the liquid storage cavity moves towards the direction close to the solid-state thermochromic phase-change material. The liquid-state thermochromic phase-change material is squeezed and then flows into the liquid storage cavity through the liquid flow channel.

[0013] As the solid-state thermochromic phase-change material gradually melts, the liquid storage cavity gradually approaches the battery surface. When the light emitted by the light source assembly is blocked by the liquid storage cavity and the photosensitive assembly cannot receive the light emitted by the light source assembly, it indicates that the solid-state thermochromic phase-change material has completely melted and entered the liquid storage cavity, and the liquid storage cavity stops moving. After the liquid-state thermochromic phase-change material in the liquid storage cavity is completely solidified, the liquid storage cavity resets under the action of the spring, and the solid-state thermochromic phase-change material contacts the battery surface again to absorb heat and undergo a phase change. This cycle continues until the surface temperature of the battery is less than the phase-change temperature, and the system stops working.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] (1) Efficient thermal management: By driving the movement of the solid-state phase change material, the liquid phase change material generated by the phase change in contact with the battery is extruded, ensuring that the battery always maintains good contact with the solid-state phase change material. The solid-state phase change material absorbs heat in the form of latent heat, effectively absorbing and transferring the heat of the battery, keeping the battery temperature within a reasonable range at all times, and avoiding performance degradation or damage caused by excessive temperature.

[0016] (2) Simplified structural design: Through the color change of the thermochromic phase change material and the synergistic effect of the photosensitive component and the light source component, a light-sensing feedback mechanism is formed to control the movement of the liquid storage cavity; by combining the phase change material, the liquid storage cavity and the light-sensing feedback mechanism, the structure is compact, the response is rapid, and efficient thermal management can be achieved within a small volume.

[0017] (3) Sustainable recycling: During the heat dissipation process of the battery, the phase change material repeatedly converts between the solid state and the liquid state. By controlling the movement of the liquid storage cavity through the light-sensing feedback mechanism, and then driving the movement of the solid-state phase change material, the battery always maintains close contact with the solid-state phase change material, realizing self-adjustment of the position of the solid-state phase change material, being able to continuously dissipate heat from the battery, and reducing the dependence on external power or cooling systems. Description of the Drawings

[0018] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 is a longitudinal sectional view of the present invention along the front and back directions of the battery;

[0020] Figure 3 is a schematic diagram of the structure of the liquid storage cavity of the present invention;

[0021] Reference numerals: 1 - battery; 2 - solid-state thermochromic phase change material; 3 - liquid storage cavity; 4 - copper rod; 5 - spring; 6 - battery housing; 7 - photosensitive component; 8 - liquid flow channel; 9 - heat conducting sheet; 10 - light source component. Detailed Embodiments

[0022] The following provides specific embodiments in conjunction with the drawings. The specific embodiments are only used to introduce the technical solutions of the present invention in detail and do not limit the protection scope of this application.

[0023] Please refer to Figures 1 to 3 , the present invention provides a battery thermal management system based on light-controlled driving contact phase change, including a solid-state thermochromic phase change material 2, a liquid storage cavity 3, a spring 5, a photosensitive component 7, a liquid flow channel 8 and a light source component 10;

[0024] One side of the solid thermochromic phase change material 2 is in close contact with one side of the battery 1, and the solid thermochromic phase change material 2 is in block shape; the liquid storage chamber 3 is a box structure with one side open, and a plurality of through holes are provided on the top of the liquid storage chamber 3 for the liquid thermochromic phase change material to flow into the liquid storage chamber 3; the open side of the liquid storage chamber 3 is in close contact with the other side of the solid thermochromic phase change material 2, and as the solid thermochromic phase change material 2 absorbs heat and gradually melts into a liquid state, the liquid storage chamber 3 can move toward the direction close to the solid thermochromic phase change material 2, and the liquid storage chamber 3 and the thermochromic phase change material 2 are in close contact with each other. A liquid flow channel 8 is formed between the upper surface and the inner wall of the battery housing 6, and the liquid thermochromic phase change material flows into the liquid storage chamber 3 through the liquid flow channel 8; one end of the spring 5 is connected to the side of the liquid storage chamber 3 opposite to the opening, and the other end is connected to the inner wall of the battery housing 6, which is used for resetting the liquid storage chamber 3; the light source component 10 and the photosensitive component 7 are located on the side where the battery 1 contacts the solid thermochromic phase change material 2, the light emitting end of the light source component 10 faces the photosensitive end of the photosensitive component 7, and the photosensitive component 7 receives the light emitted by the light source component 10 and uses it as a control signal for the movement of the liquid storage chamber 3;

[0025] The color of the solid thermochromic phase change material 2 is opaque black, so the light emitted by the light source component 10 cannot penetrate the solid thermochromic phase change material 2 and be received by the photosensitive component 7; the battery 1 generates heat during the charging and discharging process, causing the temperature to rise, and transfers the heat to the solid thermochromic phase change material 2 close to its surface, and the temperature of the solid thermochromic phase change material 2 also rises accordingly. When the surface temperature of the battery 1 is greater than or equal to the phase change temperature, the solid thermochromic phase change material 2 in close contact with the battery 1 absorbs a large amount of heat and undergoes a phase change from solid to liquid, and the color of the thermochromic phase change material also changes from black to transparent. The light emitted by the light source component 10 penetrates the liquid thermochromic phase change material and is received by the photosensitive component 7. At this time, the liquid storage chamber 3 moves in the direction close to the solid thermochromic phase change material 2. After being squeezed, the liquid thermochromic phase change material flows into the liquid storage chamber 3 from the through hole at the top of the liquid storage chamber 3 through the liquid flow channel 8; during the movement of the liquid storage chamber 3 toward the battery 1, the spring 5 will be stretched and store elastic potential energy;

[0026] As the solid-state thermochromic phase-change material 2 gradually melts, the liquid storage cavity 3 gradually approaches the surface of the battery 1. When the light emitted by the light source assembly 10 is blocked by the liquid storage cavity 3 and the photosensitive assembly 7 cannot receive the light emitted by the light source assembly 10, it indicates that the solid-state thermochromic phase-change material 2 has completely melted, the liquid storage cavity 3 stops moving, and the liquid thermochromic phase-change material completely enters the liquid storage cavity 3 and gradually solidifies. After the liquid thermochromic phase-change material is completely solidified, the liquid storage cavity 3 will move away from the solid-state thermochromic phase-change material 2 under the action of the spring 5 and return to the initial position. The solid-state thermochromic phase-change material 2 contacts the surface of the battery 1 again to absorb heat and undergo a phase change. In this cycle, when the temperature of the battery surface is lower than the phase-change temperature, the system stops working. Since the solid-state thermochromic phase-change material 2 always maintains good contact with the surface of the battery 1, the phase-change material absorbs the heat of the battery 1 in the form of latent heat, thereby improving the thermal management performance.

[0027] To prevent the liquid thermochromic phase-change material from solidifying into a solid state and blocking the liquid flow channel 8 during the flow process, a heat-conducting sheet 9 is provided in the liquid flow channel 8, and the heat-conducting sheet 9 is in contact with the battery 1. The heat of the battery 1 is transferred to the heat-conducting sheet 9. On the one hand, it prevents the liquid thermochromic phase-change material from solidifying in the liquid flow channel 8 and ensures the smoothness of the liquid flow channel 8. On the other hand, the setting of the heat-conducting sheet 9 can further improve the thermal management efficiency and ensure that the heat of the battery 1 can be transferred out in a timely and effective manner.

[0028] To ensure that the liquid storage cavity 3 can effectively push the solid-state thermochromic phase-change material 2, a copper rod 4 is provided on the opening side of the liquid storage cavity 3. During the movement of the liquid storage cavity 3 towards the solid-state thermochromic phase-change material 2, the copper rod 4 is not energized and only serves to push the solid-state thermochromic phase-change material 2. During the reset process of the liquid storage cavity 3, the copper rod 4 is energized to heat the solid-state thermochromic phase-change material 2 in contact with it to promote its melting, so that the copper rod 4 can smoothly disengage from the solid-state thermochromic phase-change material 2 to reduce the resistance during the reset process of the liquid storage cavity 3. Further, to ensure that the liquid storage cavity 3 can smoothly disengage from the solid-state thermochromic phase-change material 2, a heating sheet can be provided on the inner wall of the liquid storage cavity 3. During the process of the liquid storage cavity 3 disengaging from the solid-state thermochromic phase-change material 2, the solid-state thermochromic phase-change material 2 in contact with the liquid storage cavity 3 is heated and melted by the heating sheet. The movement of the liquid storage cavity 3 can be realized by means such as electromagnetic drive and motor drive.

[0029] The function of the liquid storage cavity 3 is not only to store the liquid thermochromic phase change material, but also to cooperate with the light source assembly 10 and the photosensitive assembly 7 to form a light-sensing feedback mechanism for controlling the movement of the liquid storage cavity 3, pushing the solid thermochromic phase change material 2 to extrude the liquid thermochromic phase change material into the liquid storage cavity 3, so that the solid thermochromic phase change material 2 always maintains good contact with the surface of the battery 1, ensuring that heat can be effectively conducted and preventing the battery 1 from overheating. This system can effectively manage the battery temperature, always keep the battery within a reasonable working temperature range during the charging and discharging process, and prevent battery performance degradation or damage caused by overheating; by combining the phase change material, the liquid storage cavity and the light-sensing feedback mechanism, it not only has a compact structure and rapid response, but also has the advantage of sustainable recycling, and can reduce the dependence on external power or cooling systems.

[0030] What is not described in this invention is applicable to the prior art.

Claims

1. A battery thermal management system based on light-controlled drive contact phase change, characterized in that It includes a thermochromic phase change material, a liquid storage cavity, a spring, a photosensitive component, a liquid flow channel, and a light source component; One side of the battery is in close contact with one side of the solid thermochromic phase change material. The open side of the liquid storage cavity is closely attached to the other side of the solid thermochromic phase change material. As the solid thermochromic phase change material gradually converts into a liquid thermochromic phase change material, the liquid storage cavity can move towards the direction close to the solid thermochromic phase change material. The solid thermochromic phase change material is opaque, while the liquid thermochromic phase change material is transparent. A number of through holes are provided at the top of the liquid storage cavity. A liquid flow channel is formed between the upper surfaces of the liquid storage cavity and the thermochromic phase change material and the inner wall of the battery housing. The liquid thermochromic phase change material flows into the liquid storage cavity through the liquid flow channel. One end of the spring is connected to the side of the liquid storage cavity opposite to the opening, and the other end is connected to the inner wall of the battery housing. The light source component and the photosensitive component are located on the side where the battery contacts the solid thermochromic phase change material. The light emitting end of the light source component faces the photosensitive end of the photosensitive component. The photosensitive component receives the light emitted by the light source component and serves as a control signal for the movement of the liquid storage cavity.

2. The battery thermal management system based on light-controlled driving contact phase change according to claim 1, characterized in that, A heat conducting sheet is provided in the liquid flow channel, and the heat conducting sheet is in contact with the battery at the same time.

3. The battery thermal management system based on light-controlled driving contact phase change according to claim 1 or 2, characterized in that, A copper rod is provided on the open side of the liquid storage cavity; during the process of the liquid storage cavity moving towards the solid thermochromic phase change material, the copper rod is not energized; during the reset process of the liquid storage cavity, the copper rod is energized.

4. The battery thermal management system based on light-controlled driving contact phase change according to claim 3, characterized in that, A heating sheet is provided on the inner wall of the liquid storage cavity; during the reset process of the liquid storage cavity, the heating sheet is energized.

5. The battery thermal management system based on light-controlled driving contact phase change according to claim 1, wherein The working process of the system is as follows: When the surface temperature of the battery is greater than or equal to the phase change temperature, the solid thermochromic phase change material in close contact with the battery undergoes a phase change and converts into a liquid state. The light emitted by the light source component penetrates the liquid thermochromic phase change material and is received by the photosensitive component. At this time, the liquid storage cavity moves towards the direction close to the solid thermochromic phase change material. After being squeezed, the liquid thermochromic phase change material flows into the liquid storage cavity through the liquid flow channel; As the solid thermochromic phase change material gradually melts, the liquid storage cavity gradually approaches the battery surface. When the light emitted by the light source component is blocked by the liquid storage cavity and the photosensitive component cannot receive the light emitted by the light source component, it indicates that the solid thermochromic phase change material has completely melted and entered the liquid storage cavity, and the liquid storage cavity stops moving; after the liquid thermochromic phase change material in the liquid storage cavity is completely solidified, the liquid storage cavity resets under the action of the spring, and the solid thermochromic phase change material contacts the battery surface again to absorb heat and undergo a phase change. This cycle continues until the surface temperature of the battery is less than the phase change temperature, and the system stops working.

Images