Integrated battery composite thermal management device

Abstract

The invention provides an integrated battery composite thermal management device which mainly solves the common problems of low thermal management efficiency, poor temperature uniformity, system complexity and the like in a traditional battery thermal management system. According to the invention, the vapor chamber vapor chamber, the phase change material chamber and the micro channel are highly integrated in the same component, and the vapor chamber vapor chamber is used for uniformly distributing the surface temperature of the battery and effectively controlling the temperature gradient of the battery within a safe range; the phase change material cavity has the characteristic of absorbing heat in the phase change process, can absorb heat of the cold end of the vapor chamber vapor chamber, and provides effective heat storage in the battery charging and discharging process; the micro-channel cooling technology can realize rapid heat dissipation, and the risk of thermal management failure caused by complete melting of the phase change material is avoided. According to the integrated design, the efficiency and the system stability of the composite thermal management system can be improved, the overall weight of the composite thermal management device can be reduced, and the installation and maintenance cost of the device is reduced.

Description

Technical Field

[0001] The present invention relates to the field of battery thermal management, and in particular to an integrated battery composite thermal management device. Background Art

[0002] Under the strategic background of the "dual carbon" goal, optimizing the energy structure and reducing carbon emissions have become important tasks for the global response to climate change. The electrification of automobiles, ships, and aircraft has become a core component of energy transformation with its significant carbon emission reduction potential. Lithium-ion batteries have become the first choice for automotive and marine batteries due to their high energy density, low self-discharge rate, and long cycle life. Lithium-ion batteries are sensitive to temperature. Too high or too low temperatures will reduce battery performance and shorten their life. The optimal operating temperature of the battery is usually 20°C to 40°C, and the temperature difference between battery modules should also be strictly controlled. Therefore, the development of an efficient and reliable battery thermal management system has become the key to ensuring battery safety and improving the overall performance of the battery.

[0003] Battery thermal management systems can use cooling methods such as air cooling, liquid cooling, phase change materials, heat pipes, and temperature equalizers. Because they each have their own advantages but also limitations, composite thermal management devices that use two or even three cooling methods have strong application prospects. Hybrid devices have high flexibility and can adapt to a variety of different application scenarios. However, the hybrid device has many components and a complex structure, which will bring the risk of reduced reliability of the thermal management system. Therefore, it is urgent to develop highly integrated battery composite thermal management devices. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art and effectively solve the problems of insufficient thermal management efficiency, poor temperature uniformity and complex system in the existing battery thermal management system, this application proposes an integrated battery composite thermal management device. The device integrates a vapor chamber heat spreader, phase change material and microchannel cold plate. The heat spreader effectively reduces the temperature difference at different positions of the battery cell, enhances the uniformity of battery temperature distribution, and avoids local overheating or overcooling; the phase change material can absorb the change in battery temperature by utilizing its heat storage and heat release characteristics during the phase change process; the microchannel cold plate is integrated into the integrated battery composite thermal management device, and its efficient heat exchange capacity can quickly take away the heat generated by the battery; the heat spreader, phase change material and microchannel cold plate share a solid wall surface, which is convenient for integrated design and manufacturing. Through reasonable structural design, the three forms of thermal management can be closely coordinated to ensure the stable and efficient operation of the entire thermal management system.

[0005] An integrated battery composite thermal management device comprises a vapor chamber heat spreader, a phase change material cavity and a microchannel; the phase change material cavity is a rectangular parallelepiped; the side of the phase change material cavity is provided with a microchannel; the microchannel is a through hole; the side of the phase change material cavity provided with the microchannel is the front side; a vapor chamber heat spreader is provided on one side of the phase change material cavity; the vapor chamber heat spreader, the phase change material cavity and the microchannel are integrally formed.

[0006] Furthermore, based on an integrated battery composite thermal management device, it includes a second steam chamber heat spreader; the second steam chamber heat spreader is arranged on the other side of the phase change material cavity; the steam chamber heat spreader, the phase change material cavity and the second steam chamber heat spreader are arranged in sequence to form a three-layer structure; the steam chamber heat spreader, the phase change material cavity, the second steam chamber heat spreader and the micro-channel are integrated into one.

[0007] Furthermore, the shape of the microchannel is a cylinder or a polyhedron; the larger the surface area shared by the microchannel and the phase change material cavity is, the better the heat dissipation effect of the cold fluid after passing through the microchannel is.

[0008] Furthermore, the number of the microchannels is greater than one.

[0009] Furthermore, the microchannel is arranged on a line connecting midpoints of short sides of the front side of the phase change material.

[0010] Furthermore, the microchannel is arranged on one side or both sides of a line connecting the midpoints of the short sides of the front side of the phase change material.

[0011] The beneficial effects of the present invention are:

[0012] 1. The integrated battery composite thermal management device can achieve complementary advantages of cooling effects of multiple thermal management methods by integrating the vapor chamber heat sink, phase change material and micro-channel cold plate;

[0013] 2. The integrated battery composite thermal management device reduces the contact thermal resistance in the split composite thermal management system, improves the thermal management capability of the device, facilitates modular prefabrication and can reduce the size and weight of the device.

[0014] 3. The integrated battery composite thermal management device avoids the installation, coordination and debugging process between multiple components of the split composite thermal management system, and can improve the reliability and practicality of the composite thermal management system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of a symmetrically distributed integrated battery composite thermal management device

[0016] Figure 2Schematic diagram of an asymmetrically distributed integrated battery composite thermal management device

[0017] Figure 3 A partial schematic diagram of a battery pack using a symmetrically distributed integrated battery composite thermal management device

[0018] Figure 4 It is a partial schematic diagram of a battery pack using an asymmetrically distributed integrated battery composite thermal management device;

[0019] Among them, 1-vapor chamber heat spreader; 1'-second vapor chamber heat spreader; 2-phase change material cavity; 3-micro channel; 4-hot end of vapor chamber heat spreader; 5-solid wall shared by cold end of vapor chamber heat spreader and phase change material cavity; 6-solid wall shared by micro channel and phase change material cavity; 7-battery core. DETAILED DESCRIPTION

[0020] An integrated battery composite thermal management device comprises a vapor chamber heat spreader, a phase change material cavity and a microchannel; the phase change material cavity is a rectangular parallelepiped; the side of the phase change material cavity is provided with a microchannel; the microchannel is a through hole; the side of the phase change material cavity provided with the microchannel is the front side; a vapor chamber heat spreader is provided on one side of the phase change material cavity; the vapor chamber heat spreader, the phase change material cavity and the microchannel are integrally formed.

[0021] An integrated battery composite thermal management device includes a second steam chamber heat spreader; the second steam chamber heat spreader is arranged on the other side of a phase change material cavity; the steam chamber heat spreader, the phase change material cavity and the second steam chamber heat spreader are arranged in sequence to form a three-layer structure; the steam chamber heat spreader, the phase change material cavity, the second steam chamber heat spreader and the microchannel are integrally formed.

[0022] The shape of the micro-channel is a cylinder or a polyhedron; the larger the surface area shared by the micro-channel and the phase change material cavity is, the better the heat dissipation effect of the cold fluid after passing through the micro-channel is.

[0023] The number of the microchannels is greater than one.

[0024] The microchannel is arranged on a line connecting the midpoints of the short sides of the front side of the phase change material.

[0025] The microchannel is arranged on one side or both sides of a line connecting the midpoints of the short sides of the front side of the phase change material.

[0026] When in use, the hot end of the vapor chamber is placed close to the battery cell. After absorbing the heat released by the battery cell, the liquid in the vapor chamber vaporizes into steam, which quickly diffuses in the cavity of the vapor chamber vapor chamber. After encountering the solid wall shared by the cold end of the vapor chamber vapor chamber and the phase change material cavity, it releases heat and condenses into liquid. The condensed liquid is sucked back to the hot end under the capillary action of the capillary core arranged inside the vapor chamber vapor chamber. This cycle is repeated to achieve efficient heat transfer.

[0027] The phase change material filled in the phase change material cavity absorbs heat. When the temperature of the battery cell is too high, the phase change material cavity absorbs heat from the solid wall shared by the cold end of the vapor chamber heat spreader and the phase change material cavity and gradually changes from solid to liquid. The heat is stored in the phase change material, thereby reducing the temperature of the battery cell.

[0028] When the battery dissipates heat, a cold fluid is introduced into the microchannel to quickly take away the heat in the phase change material cavity. The shape of the microchannel is not limited to a rectangular straight channel, and different geometric shapes and structural types can be used. The number of microchannels is also only a schematic description, and can be flexibly designed according to needs in actual applications. The microchannel can be arranged in the middle of the two phase change material cavities, or on one side or both sides.

[0029] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0030] Figure 1 Schematic diagram of a symmetrically distributed integrated battery thermal management device. Specifically, the symmetrically distributed integrated battery thermal management device refers to a phase change material cavity with a vapor chamber heat sink on both sides, showing a symmetrical distribution. Figure 2 Schematic diagram of an asymmetrically distributed integrated battery thermal management device. Specifically, an asymmetrically distributed integrated battery thermal management device refers to a phase change material cavity having a vapor chamber heat sink on only one side.

[0031] Figure 3 This is a partial schematic diagram of a battery pack using a symmetrically distributed integrated composite battery thermal management device. Figure 4 It is a partial schematic diagram of a battery pack using an asymmetrically distributed integrated battery thermal management device. Specifically, the integrated composite battery thermal management device can be installed between battery cells. The specific structure of the integrated composite battery thermal management device can be freely selected based on the heating characteristics of the battery cells, the battery cell layout, the thermophysical properties of the phase change material, the microchannel structure, the thermophysical properties of the fluid in the microchannel, etc., and a symmetrically distributed integrated battery thermal management device or an asymmetrically distributed integrated electric thermal management device and its derivative structure can be selected;

[0032] The function of the heat spreader is to even out the battery temperature and ensure that the temperature gradient of the battery remains within a reasonable range, thereby avoiding problems such as reduced battery performance, reduced efficiency, and shortened cycle life due to excessive temperature gradients.

[0033] The hot end of the vapor chamber is in close contact with the battery surface, and its large equivalent thermal coefficient can quickly transfer the heat generated by the battery. When the hot end absorbs heat, the liquid working fluid in the vapor chamber evaporates into steam. The steam then condenses at the cold end, releasing latent heat and converting into condensate. A capillary wick structure is arranged inside the vapor chamber, which guides the condensate back to the hot end through capillary action to form a closed loop.

[0034] The cold end of the vapor chamber shares a solid wall with the cavity encapsulating the phase change material. This can effectively avoid the additional contact thermal resistance generated by the split design, thereby improving the overall heat transfer efficiency. This design not only reduces the thermal resistance but also effectively reduces the overall weight of the battery thermal management device.

[0035] The function of the phase change material is to absorb the heat of the battery. The heat quickly transferred by the battery through the heat spreader is first absorbed by the phase change material at the condensation end, and the phase change material melts when it exceeds the melting point. During the charge and discharge process of the battery, the phase change material can be dynamically adjusted according to the heat generated by the battery, and the battery can be kept operating within the ideal temperature range by absorbing excess heat or releasing stored heat.

[0036] The phase change material is encapsulated in a closed cavity and does not directly contact the battery, which has the advantage of reducing the leakage problem caused by the chemical instability and expansion of the phase change material.

[0037] A micro-channel is also integrated in the cavity encapsulating the phase change material. The wall of the micro-channel and the cavity encapsulating the phase change material share a solid wall, which also reduces the thermal resistance and the weight of the device.

[0038] The cooling fluid is introduced into the microchannel, which can efficiently take away the heat generated by the battery to the outside for final cooling.

Claims

1. An integrated battery composite thermal management device, characterized in that: It includes a steam chamber heat spreader, a phase change material cavity and a microchannel; the phase change material cavity is a rectangular parallelepiped; the side of the phase change material cavity is provided with a microchannel; the microchannel is a through hole; the side of the phase change material cavity provided with the microchannel is the front side; a steam chamber heat spreader is provided on one side of the phase change material cavity; the steam chamber heat spreader, the phase change material cavity and the microchannel are integrally formed.

2. The integrated battery composite thermal management device according to claim 1, characterized in that: It includes a second steam chamber heat spreader; the second steam chamber heat spreader is arranged on the other side of the phase change material cavity; the steam chamber heat spreader, the phase change material cavity and the second steam chamber heat spreader are arranged in sequence to form a three-layer structure; the steam chamber heat spreader, the phase change material cavity, the second steam chamber heat spreader and the microchannel are integrated into one.

3. An integrated battery composite thermal management device according to claim 1 or claim 2, characterized in that: The shape of the microchannel is a cylinder or a polyhedron; the larger the surface area shared by the microchannel and the phase change material cavity is, the better the heat dissipation effect of the cold fluid after passing through the microchannel is.

4. An integrated battery composite thermal management device according to claim 1 or claim 2, characterized in that: The number of the microchannels is greater than one.

5. The integrated battery composite thermal management device according to claim 4, characterized in that: The microchannel is arranged on a line connecting the midpoints of the short sides of the front side of the phase change material.

6. The integrated battery composite thermal management device according to claim 1, characterized in that: The microchannel is arranged on one side or both sides of a line connecting the midpoints of the short sides of the front side of the phase change material.

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