A lithium battery cooling device and method of use

Abstract

The application relates to the technical field of battery cooling, in particular to a lithium battery cooling device and a use method. The lithium battery cooling device comprises a cooling shell, the cooling shell comprises an air inlet cavity, an elastic air storage cavity and an air outlet cavity which are communicated, the air inlet cavity is provided with an air inlet, the air outlet cavity is provided with an air outlet, the air outlet cavity and the air inlet cavity are respectively arranged at two ends of the elastic air storage cavity, and the air inlet cavity, the elastic air storage cavity and the air outlet cavity form a containing space. The application provides a lithium battery cooling device and a use method, so as to solve the problem that the existing jet flow cooling system still has low system integration, thereby causing a complex structure.

Description

Technical Field

[0001] This invention relates to the field of battery cooling technology, specifically to a lithium battery cooling device and its usage method. Background Technology

[0002] With the rapid development of new energy technologies, lithium-ion batteries, as core components for energy storage and conversion, have been widely used in key areas such as electric vehicles and energy storage power stations. In the continuous breakthroughs in battery technology, the widespread adoption of high-energy-density cells and the iteration of fast-charging technology have significantly increased the heat generation power of battery packs. For every 10°C increase in the operating temperature of a single cell, the battery cycle life will be shortened by approximately 50%. Localized hot spots generated under extreme operating conditions can even trigger a thermal runaway chain reaction, seriously threatening system safety. Therefore, efficient and reliable battery cooling technology has become a key technological bottleneck restricting the development of the new energy industry.

[0003] Currently, lithium-ion battery thermal management technologies mainly include the following categories: (1) natural cooling technology; (2) forced air cooling technology; (3) liquid cooling technology; (4) phase change material cooling technology; and (5) composite cooling technology (such as cold plate integration, heat pipe coupling, etc.). According to the thermal management method, they can be divided into two major categories: passive temperature control and active temperature control. Among the above technical solutions, directional jet cooling and embedded heat pipe technology are considered to be the most promising battery thermal management solutions. Among them, jet cooling technology has shown significant effects in the field of battery pack temperature control due to its advantages such as high convective heat transfer coefficient and fast temperature response speed.

[0004] Existing jet cooling systems still suffer from technical bottlenecks such as low system integration and complex structure, which severely restrict their large-scale application in space-sensitive scenarios such as vehicle battery packs. Summary of the Invention

[0005] In view of this, the present invention provides a lithium battery cooling device and a method of use to solve the problem that existing jet cooling systems still have low system integration and complex structure.

[0006] In a first aspect, the present invention provides a lithium battery cooling device, comprising: A cooling housing, the cooling housing comprising an air inlet chamber, an elastic air storage chamber, and an air outlet chamber connected in communication; An air intake chamber is provided with an air inlet; The air outlet chamber is provided with an air outlet, and the air outlet chamber and the air inlet chamber are respectively located at both ends of the elastic air storage chamber. The air inlet chamber, the elastic air storage chamber and the air outlet chamber form a receiving space.

[0007] In the intake state, the outlet is closed, increasing the volume of the elastic air storage chamber, allowing ambient air to enter through the intake chamber. In the exhaust state, the intake is closed, decreasing the volume of the elastic air storage chamber, allowing ambient air to exit through the exhaust chamber. The entire casing is integrated into a single unit. By designing intake and exhaust states, air can quickly carry away dissipated heat, resulting in a relatively simple structure that effectively achieves cooling.

[0008] In one optional embodiment, an intake piezoelectric film is provided in the intake chamber, and a gap is left between the intake piezoelectric film and the intake port. The intake piezoelectric film closes the intake port when the air is being discharged. An outlet piezoelectric film is provided in the outlet chamber, and a gap is left between the outlet piezoelectric film and the outlet port. The outlet piezoelectric film closes the outlet port when the air is being discharged.

[0009] In one optional embodiment, an intake valve is provided on the pipe of the air inlet, and an outlet valve is provided on the pipe of the air outlet.

[0010] In one alternative embodiment, the elastic gas storage chamber includes at least one piezoelectric film, at least one of the piezoelectric films being deformed in either an inlet or outlet state.

[0011] In one optional embodiment, the elastic gas storage chamber includes a first piezoelectric film and a second piezoelectric film disposed opposite to each other. The first piezoelectric film and the second piezoelectric film deform in the gas intake state to increase the volume of the accommodating space, and the first piezoelectric film and the second piezoelectric film deform in the gas exhaust state to decrease the volume of the accommodating space.

[0012] In an alternative embodiment, a battery pack is also included, with the cooling housing disposed on the housing of the battery pack.

[0013] In an alternative embodiment, the system further includes a battery pack, the housing of which is connected to the cooling housing via piping.

[0014] In one optional embodiment, an AC power source is further included, which is connected to the circuitry of the first piezoelectric film, the second piezoelectric film, the inlet piezoelectric film, and the outlet piezoelectric film, respectively.

[0015] In one optional embodiment, the device further includes a controller and a plurality of strain gauges, wherein the first piezoelectric film, the second piezoelectric film, the inlet piezoelectric film, and the outlet piezoelectric film are each provided with strain gauges, and the controller is connected to each of the strain gauges and the AC power supply line.

[0016] Secondly, the present invention also provides a method of using a lithium battery cooling device. In the air intake state, the air outlet is closed, the volume of the elastic air storage chamber increases, and the air from the external environment enters into the elastic air storage chamber through the air intake chamber; in the air outlet state, the air inlet is closed, the volume of the elastic air storage chamber decreases, and the air from the external environment flows out of the elastic air storage chamber through the air outlet chamber. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the lithium battery cooling device in the air intake state according to Embodiment 1 of the present invention. Figure 2 This is a schematic diagram of the lithium battery cooling device in the gas venting state according to Embodiment 1 of the present invention. Figure 3 This is a schematic diagram of the lithium battery cooling device and battery pack in embodiment 1 of the present invention. Figure 4 This is a schematic diagram of the lithium battery cooling device and battery pack in embodiment 2 of the present invention. Figure 5 This is a schematic diagram of the lithium battery cooling device according to Embodiment 2 of the present invention.

[0019] Explanation of reference numerals in the attached drawings: 1. Inlet chamber; 2. Outlet chamber; 3. Elastic gas storage chamber; 4. Inlet; 5. Outlet; 6. First piezoelectric film; 7. Second piezoelectric film; 8. Battery pack; 9. AC power supply; 10. Thermometer; 11. Inlet valve; 12. Outlet valve; 13. Inlet piezoelectric film; 14. Outlet piezoelectric film. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1 The following is combined with Figures 1 to 3 The following describes embodiments of the present invention.

[0022] According to an embodiment of the present invention, a lithium battery cooling device is provided, comprising: a cooling housing, the cooling housing including an inlet chamber 1, an elastic gas storage chamber 3 and an outlet chamber 2 connected in communication; the inlet chamber 1 is provided with an inlet 4; the outlet chamber 2 is provided with an outlet 5, the outlet chamber 2 and the inlet chamber 1 are respectively located at both ends of the elastic gas storage chamber 3, and the inlet chamber 1, the elastic gas storage chamber 3 and the outlet chamber 2 form a receiving space.

[0023] In the intake state, the outlet 5 is closed, increasing the volume of the elastic air storage chamber 3, allowing ambient air to enter the elastic air storage chamber 3 through the intake chamber 1. In the exhaust state, the outlet 4 is closed, decreasing the volume of the elastic air storage chamber 3, allowing ambient air to flow out through the exhaust chamber 2. The entire casing is integrated into one unit. By setting intake and exhaust states, air can quickly carry away dissipated heat, resulting in a relatively simple structure that achieves a cooling effect.

[0024] In one embodiment, such as Figure 1 , Figure 2 As shown, an intake piezoelectric diaphragm 13 is provided in the intake chamber 1, with a gap between the intake piezoelectric diaphragm 13 and the intake port 4. In the exhaust state, the intake piezoelectric diaphragm 13 closes the intake port 4. An exhaust piezoelectric diaphragm 14 is provided in the exhaust chamber 2, with a gap between the exhaust piezoelectric diaphragm 14 and the exhaust port 5. In the intake state, the exhaust piezoelectric diaphragm 14 closes the exhaust port 5. By setting the intake piezoelectric diaphragm 13 and the exhaust piezoelectric diaphragm 14, the intake piezoelectric diaphragm 13 is open in the intake state, and the exhaust piezoelectric diaphragm 14 is closed in the intake state. External gas enters through the intake port 4, and the exhaust port 5 cannot flow out, thereby increasing the gas volume within the containment space. In the exhaust state, the intake piezoelectric diaphragm 13 closes the intake port 4, and the exhaust piezoelectric diaphragm 14 opens the exhaust port 5, allowing the gas within the containment space to flow out through the exhaust port 5, thus realizing the flow of gas within the containment space and generating heat within the containment space.

[0025] In one embodiment, such as Figure 1 , Figure 2 As shown, the elastic gas storage chamber 3 includes at least one piezoelectric film. The piezoelectric film deforms in either the gas inlet or gas outlet state. In the gas inlet state, the deformation increases the volume of the storage space, and in the gas outlet state, it decreases the volume of the storage space. It should be noted that the deformation directions of the piezoelectric film are opposite in the gas inlet and gas outlet states.

[0026] In one embodiment, such as Figure 1 , Figure 2As shown, the elastic gas storage chamber 3 includes a first piezoelectric film 6 and a second piezoelectric film 7 disposed opposite to each other. The first piezoelectric film 6 and the second piezoelectric film 7 deform in the gas intake state to increase the volume of the accommodating space, and deform in the gas exhaust state to decrease the volume of the accommodating space. In this embodiment, in the gas intake state, the first piezoelectric film 6 and the second piezoelectric film 7 deform in a direction away from each other, that is, the first piezoelectric film 6 deforms in a direction away from the second piezoelectric film 7, and the second piezoelectric film 7 deforms in a direction away from the first piezoelectric film 6; in the gas exhaust state, the first piezoelectric film 6 and the second piezoelectric film 7 deform in a direction closer to each other, that is, the first piezoelectric film 6 deforms in a direction closer to the second piezoelectric film 7, and the second piezoelectric film 7 deforms in a direction closer to the first piezoelectric film 6.

[0027] In this embodiment, the inlet piezoelectric film 13, the outlet piezoelectric film 14, the first piezoelectric film 6, and the second piezoelectric film 7 are all thin-film piezoelectric materials. The materials should be polyvinylidene fluoride (PVDF) (film), other organic piezoelectric (film) materials represented by PVDF (film), piezoelectric crystals, or piezoelectric ceramics. Furthermore, the inlet chamber 1 has a gradually expanding and contracting structure, providing space for the movement of the inlet piezoelectric film 13 within the chamber. The constituent material should be a metal or non-metal material with a certain mechanical strength. Similarly, the outlet chamber 2 should have a gradually expanding and contracting structure, providing space for the movement of the outlet piezoelectric film 14 within the chamber. The constituent material should be a metal or non-metal material with a certain mechanical strength.

[0028] In one embodiment, such as Figure 1 , Figure 2 , Figure 3 As shown, it also includes a battery pack 8, with a cooling housing disposed on the casing of the battery pack 8. The battery pack 8 generates heat, which is dissipated to the outside of the battery pack 8. The gas flow of the lithium battery cooling device quickly removes the heat dissipated by the battery pack 8. In this embodiment, the cooling housing consists of an inlet chamber 1, a flexible gas storage chamber 3, and an outlet chamber 2. Figure 3 As shown, the battery pack 8 includes several batteries, each battery corresponding to a cooling housing, which is fixed to the battery casing. In this embodiment, the method of fixing the cooling housing to the battery is not specifically limited; it can be glued, plugged in, or other methods.

[0029] In one embodiment, such as Figure 1 , Figure 2 , Figure 3As shown, it also includes an AC power supply 9, which is connected to the circuits of the first piezoelectric film 6, the second piezoelectric film 7, the inlet piezoelectric film 13, and the outlet piezoelectric film 14. The AC power supply 9 provides current in different directions within one cycle, causing the first piezoelectric film 6, the second piezoelectric film 7, the inlet piezoelectric film 13, and the outlet piezoelectric film 14 to deform in different directions within one cycle.

[0030] In one embodiment, such as Figure 1 As shown, it also includes a controller and several strain gauges. The first piezoelectric film 6, the second piezoelectric film 7, the inlet piezoelectric film 13 and the outlet piezoelectric film 14 are each equipped with a strain gauge. The controller is connected to each strain gauge and the AC power supply 9 line respectively.

[0031] A method of using a lithium battery cooling device, comprising a no-power state, an air-intake state, and an air-out state, includes the following steps: (1) In the absence of electricity, when no current passes through, the first piezoelectric film 6 and the second piezoelectric film 7 are in parallel, the inlet piezoelectric film 13 and the outlet piezoelectric film 14 are in parallel, no gas passes through the inlet 4 and the outlet 5, and the lithium battery cooling device is in a stable non-operating state. (2) After the AC power is introduced, in the air intake state, the first piezoelectric film 6 and the second piezoelectric film 7 undergo mechanical deformation under the action of the electric field, and both gradually expand outward. At the same time, the air intake piezoelectric film 13 expands outward to open the air intake port 4 for gas to enter, and the air outlet piezoelectric film 14 contracts inward to isolate the elastic storage chamber 3 from the air outlet chamber 2. The deformation of the first piezoelectric film 6 and the second piezoelectric film 7 causes the volume of the elastic storage chamber 3 to increase and the air pressure to decrease. The pressure difference between the elastic storage chamber 3 and the atmosphere causes air to enter the elastic storage chamber 3 from the air intake port 4 through the air intake chamber 1 to maintain pressure balance and complete the air intake state. At the same time, the strain gauges set on the first piezoelectric film 6, the second piezoelectric film 7, the air intake piezoelectric film 13 and the air outlet piezoelectric film 14 monitor the deformation in real time and feed it back to the controller. The closed-loop control of the deformation direction and amplitude is achieved by adjusting the phase and amplitude of the AC power (e.g., using sine wave or square wave modulation). (3) When the alternating current changes in the direction of voltage in the same cycle, in the gas outlet state, the first piezoelectric film 6 and the second piezoelectric film 7 undergo mechanical deformation under the action of the electric field and gradually shrink inward; at the same time, the gas outlet piezoelectric film 14 expands outward to open the gas outlet channel of the elastic gas storage chamber 3, and the gas inlet piezoelectric film 13 shrinks inward to isolate the elastic gas storage chamber 3 from the gas inlet chamber 1. The first piezoelectric film 6 and the second piezoelectric film 7 cause the volume of the elastic gas storage chamber 3 to shrink and the gas pressure to rise. The pressure difference between the elastic gas storage chamber 3 and the atmosphere causes the air to maintain pressure balance from the elastic gas storage chamber 3 through the gas outlet chamber 2 and the gas outlet 5, thus completing the gas outlet state.

[0032] Through the action of alternating current, the lithium battery cooling device continuously undergoes a process of "air intake → air exhaust → air intake → air exhaust...", which can quickly remove the heat dissipated by the battery casing.

[0033] The lithium battery cooling device provided by the present invention has the following advantages: (1) In the air intake state, the air outlet 5 is closed, the volume of the elastic gas storage chamber 3 increases, and the air from the external environment enters into the elastic gas storage chamber 3 through the air intake chamber 1; in the air outlet state, the air inlet 4 is closed, the volume of the elastic gas storage chamber 3 decreases, and the air from the external environment flows out to the outside of the elastic gas storage chamber 3 through the air outlet chamber 2. The entire shell is integrated into one unit. By setting the air intake and exhaust states, the air can quickly carry away the dissipated heat. The entire structure is relatively simple, so as to achieve the cooling effect. (2) Compared with the device without piezoelectric film control, it can make the gas flow in a directional manner instead of repeatedly circulating on the surface of the lithium-ion battery, which better forms convective heat transfer and avoids the gas circulating near the high-temperature device and is difficult to discharge, further improving the heat transfer efficiency of the lithium-ion battery. (3) Compared with the traditional jet device and the traditional active convective heat transfer structure, this device is smaller and has a simpler structure. During operation, the piezoelectric film is controlled by the change of current. The overall process has low noise and lower energy consumption. (4) Piezoelectric materials have good self-bearing capacity, self-diagnosis, self-adaptation and self-repair functions. Piezoelectric materials have piezoelectric effect and inverse piezoelectric effect. The inverse piezoelectric effect refers to the piezoelectric material producing directional mechanical deformation under the action of an external electric field. Piezoelectric materials, under the inverse piezoelectric effect, can respond quickly to changes in the electric field. They are quieter and consume less power during mechanical deformation. Furthermore, piezoelectric materials can be made into small structures such as thin films, giving lithium battery cooling devices outstanding advantages such as directional output, high efficiency and energy saving, quiet and stable operation, and small size in the cooling of lithium-ion batteries.

[0034] Example 2 In this embodiment, except for the structures of the inlet chamber 1 and the outlet chamber 2, the remaining structures are completely identical to those in Embodiment 1. In this embodiment, as... Figure 4 , Figure 5 As shown, an intake valve 11 is installed on the pipeline of the intake port 4, and an exhaust valve 12 is installed on the pipeline of the exhaust port 5.

[0035] During use, in the air intake state, the air intake valve 11 is opened and the air outlet valve 12 is closed. The first piezoelectric film 6 and the second piezoelectric film 7 undergo mechanical deformation under the action of the electric field, and both gradually expand outward. The deformation of the first piezoelectric film 6 and the second piezoelectric film 7 causes the volume of the elastic air storage chamber 3 to increase and the air pressure to decrease. The pressure difference between the elastic air storage chamber 3 and the atmosphere causes air to enter the elastic air storage chamber 3 from the air intake port 4 through the air intake chamber 1 to maintain pressure balance and complete the air intake state. In the air-out state, the air-out valve 12 is opened and the air-in valve 11 is closed. The first piezoelectric film 6 and the second piezoelectric film 7 undergo mechanical deformation under the action of the electric field, and both gradually contract inward. The first piezoelectric film 6 and the second piezoelectric film 7 cause the volume of the elastic air-storage chamber 3 to decrease and the air pressure to increase. The pressure difference between the elastic air-storage chamber 3 and the atmosphere causes air to flow from the elastic air-storage chamber 3 through the air-out chamber 2 and through the air-out port 5 to maintain pressure balance, thus completing the air-out state.

[0036] As an alternative implementation, a battery pack 8 is also included, the housing of which is connected to a cooling housing pipe, that is, the airflow generated by the cooling housing is sprayed onto the surface of the battery pack 8 through the pipe to remove the heat from the surface of the battery pack 8.

[0037] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A lithium battery cooling device, characterized in that, include: The cooling housing includes an air inlet chamber (1), an elastic air storage chamber (3), and an air outlet chamber (2) that are connected in series. The air intake chamber (1) is provided with an air inlet (4); The air outlet chamber (2) is provided with an air outlet (5). The air outlet chamber (2) and the air inlet chamber (1) are respectively located at both ends of the elastic air storage chamber (3). The air inlet chamber (1), the elastic air storage chamber (3) and the air outlet chamber (2) form a accommodating space.

2. The lithium battery cooling device according to claim 1, characterized in that, The air intake chamber (1) is provided with an air intake piezoelectric film (13), and there is a gap between the air intake piezoelectric film (13) and the air intake port (4). The air intake piezoelectric film (13) closes the air intake port (4) in the air exhaust state. The air exhaust chamber (2) is provided with an air exhaust piezoelectric film (14), and there is a gap between the air exhaust piezoelectric film (14) and the air exhaust port (5). The air exhaust piezoelectric film (14) closes the air exhaust port (5) in the air intake state.

3. The lithium battery cooling device according to claim 1, characterized in that, An air inlet valve (11) is provided on the pipeline of the air inlet (4) shown, and an air outlet valve (12) is provided on the pipeline of the air outlet (5).

4. The lithium battery cooling device according to claim 2 or 3, characterized in that, The elastic gas storage chamber (3) includes at least one piezoelectric film, at least one of the piezoelectric films being deformed in the gas inlet or gas outlet state.

5. The lithium battery cooling device according to claim 4, characterized in that, The elastic gas storage chamber (3) includes a first piezoelectric film (6) and a second piezoelectric film (7) arranged opposite to each other. The first piezoelectric film (6) and the second piezoelectric film (7) deform in the air intake state to increase the volume of the storage space, and the first piezoelectric film (6) and the second piezoelectric film (7) deform in the air exhaust state to decrease the volume of the storage space.

6. The lithium battery cooling device according to claim 5, characterized in that, It also includes a battery pack (8), and the cooling housing is disposed on the housing of the battery pack (8).

7. The lithium battery cooling device according to claim 5, characterized in that, It also includes a battery pack (8), the housing of which is connected to the cooling housing pipeline.

8. The lithium battery cooling device according to claim 6, characterized in that, It also includes an AC power supply (9), which is connected to the lines of the first piezoelectric film (6), the second piezoelectric film (7), the inlet piezoelectric film (13), and the outlet piezoelectric film (14), respectively.

9. The lithium battery cooling device according to claim 8, characterized in that, It also includes a controller and several strain gauges. The first piezoelectric film (6), the second piezoelectric film (7), the inlet piezoelectric film (13) and the outlet piezoelectric film (14) are respectively provided with strain gauges. The controller is connected to each of the strain gauges and the AC power supply (9) line respectively.

10. A method of using a lithium battery cooling device, for using the lithium battery cooling device according to claim 1, characterized in that, In the intake state, the outlet (5) is closed, the volume of the elastic storage chamber (3) increases, and the air from the external environment enters the elastic storage chamber (3) through the intake chamber (1); in the exhaust state, the outlet (4) is closed, the volume of the elastic storage chamber (3) decreases, and the air from the external environment flows out of the elastic storage chamber (3) through the exhaust chamber (2).

Images