A power battery cooling and protection system based on a porous medium filled with a phase change material

Abstract

The present invention discloses a power battery cooling and protection system based on a porous medium filled with a phase change material, which includes N battery monomers and N - 1 porous medium liquid cooling plates stacked alternately in sequence; the porous medium liquid cooling plates are arrayed in a face-centered cubic manner using closed-cell negative Poisson's ratio unit cells between two heat conducting plates, and are divided into a centrally sealed second cavity and a cooling flow channel surrounding the second cavity; the cooling flow channel and the second cavity are both filled with open-cell negative Poisson's ratio unit cells arrayed in a face-centered cubic manner; the voids in the second cavity are filled with a phase change material, and the voids in the cooling flow channel are filled with a cooling medium. The present invention has high heat dissipation efficiency, reliable heat dissipation temperature performance, long heat dissipation cycle, good temperature uniformity, and mechanical properties, and is used for heat dissipation and anti-collision of power batteries with high power and high charging cycles, which can improve the working performance and stability of the battery module.

Description

Technical Field

[0001] The present invention relates to the technical field of power battery temperature control, and particularly to a power battery cooling and protection system based on a porous medium filled with a phase change material. Background Art

[0002] Due to the advantages of low noise, low pollution, simple structure, convenient use and maintenance, and high energy conversion efficiency, electric vehicles have gradually become the future development direction of automobiles. And the power battery, which is the heart of an electric vehicle, is the power source of the vehicle and also a key factor affecting the development of electric vehicles.

[0003] In recent years, with the rapid development of electric vehicles, people's requirements for the driving range, fast charging characteristics and power of electric vehicles have been continuously improved. At the same time, the demand for power batteries with high energy density and power density has also been growing rapidly. However, the thermal safety of lithium-ion batteries with high energy density and power density is still the main problem faced by the development of lithium-ion batteries and electric vehicles. Higher energy density and power density mean that more heat will be generated during their operation, resulting in a drastic change in the internal temperature of lithium-ion batteries. Research shows that the charging and discharging capacity, cycle life and thermal safety of power batteries largely depend on temperature. Once the battery material is within an abnormal temperature range, the performance and stability of lithium-ion batteries will rapidly decline. Too low temperature will cause the internal resistance and polarization internal resistance of lithium-ion batteries to increase, the power and energy loss to become larger, and the discharge capacity of the battery to become smaller; too high temperature will exacerbate the degradation rate of the battery, thereby reducing the working performance and cycle life. Therefore, temperature has a great impact on the performance of battery devices, and controlling a stable and appropriate temperature plays a decisive role in improving the performance of batteries.

[0004] Currently, power battery devices mainly use the method of forced air convection heat transfer for heat dissipation and cooling, that is, forcing air to flow on the outer shell of a single battery to take away its heat. Due to the disadvantages of low thermal conductivity and small heat capacity of air, the heat transfer coefficient is small, and the heat dissipation and cooling efficiency is low. Moreover, the uneven flow of air in the battery device will affect the temperature uniformity of the battery device. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a power battery cooling and protection system based on a porous medium filled with a phase change material for the defects involved in the background art.

[0006] The present invention adopts the following technical solutions to solve the above technical problems:

[0007] A power battery cooling and protection system based on a porous medium filled with a phase change material, comprising N battery monomers and N - 1 porous medium liquid cooling plates, where N is a natural number greater than or equal to 2;

[0008] The porous medium liquid cooling plate is in the shape of a cuboid and includes a first to a second heat conducting plate, a first to a fourth outer frame, and a first to a fourth inner frame. Among them, the first to the second heat conducting plates have the same structure, are both rectangular, and are arranged in parallel; the first to the fourth outer frames are sequentially and perpendicularly fixedly connected end to end, are arranged between the first heat conducting plate and the second heat conducting plate, and are hermetically and fixedly connected to the first heat conducting plate and the second heat conducting plate, so that a sealed first cavity is formed between the first to the second heat conducting plates and the first to the fourth outer frames; the first to the fourth inner frames are sequentially and perpendicularly fixedly connected end to end, are arranged in the first cavity, and are hermetically and fixedly connected to the first heat conducting plate and the second heat conducting plate, so that a sealed second cavity is formed between the first to the second heat conducting plates and the first to the fourth inner frames, and a cooling flow channel is formed between the first to the fourth outer frames and the first to the fourth inner frames; a first through hole for the coolant to flow into the cooling flow channel is provided on the first outer frame, and a second through hole for the coolant to flow out of the cooling flow channel is provided on the third outer frame;

[0009] The first to the fourth outer frames and the first to the fourth inner frames are all formed by arranging closed-cell negative Poisson's ratio unit cells in a face-centered cubic manner; the closed-cell negative Poisson's ratio unit cell is an Archimedean tetrakaidecahedron, which is solid inside, and conical blind holes pointing to its center are provided at the centers of 8 triangular faces thereon, and the bottom of the conical blind hole is a spherical surface protruding outward;

[0010] The cooling flow channel and the second cavity are both filled by arranging open-cell negative Poisson's ratio unit cells in a face-centered cubic manner. The open-cell negative Poisson's ratio unit cell is an Archimedean tetrakaidecahedron, a spherical cavity is provided at its center, and conical through holes communicating with the spherical cavity inside are provided at the centers of 8 triangular faces on the open-cell negative Poisson's ratio unit cell;

[0011] The voids between the open-cell negative Poisson's ratio unit cells in the second cavity are filled with a phase change material, and the voids between the open-cell negative Poisson's ratio unit cells in the cooling flow channel are filled with a cooling medium;

[0012] The battery cell is in the shape of a cuboid. N battery cells and N - 1 porous medium liquid cooling plates are alternately stacked in sequence, and the electrode orientations of the N battery modules are the same; the first through holes and the second through holes of the N - 1 porous medium liquid cooling plates are both connected to an external cooling circulation system.

[0013] As a further optimized scheme of the power battery cooling and protection system based on porous medium filled with phase change material of the present invention, the phase change material is composed of a saturated fatty acid or a composite of a straight-chain alkane and expanded graphite, and its phase change temperature is 40 - 50 °C.

[0014] As a further optimized scheme of the power battery cooling and protection system based on porous medium filled with phase change material of the present invention, both the open-cell negative Poisson's ratio unit cell and the closed-cell negative Poisson's ratio unit cell are made of aluminum or aluminum alloy.

[0015] As a further optimized solution of the power battery cooling and protection system based on porous medium filled with phase change material in the present invention, the first through-hole and the second through-hole are filled with open-cell negative Poisson's ratio unit cells in a face-centered cubic array.

[0016] Compared with the prior art, the present invention adopts the above technical solutions and has the following technical effects:

[0017] 1. The phase change material in the present invention has a high thermal conductivity and a strong heat storage capacity, so that the heat storage and heat dissipation rates of the battery heat dissipation device are high;

[0018] 2. The porous medium liquid cooling plate in the present invention has a negative Poisson's ratio structure and has good anti-collision performance;

[0019] 3. The present invention uses negative Poisson's ratio unit cells for heat conduction and heat exchange between battery monomers, and has a high heat exchange coefficient and a faster heat transfer rate;

[0020] 4. The surface area of the negative Poisson's ratio unit cells in the present invention is large, so that the contact area between the fluid and the solid matrix is large, and the overall heat dissipation efficiency is higher;

[0021] 5. The phase change material filling area in the present invention is in contact with the central high-temperature area of the battery monomer, so that the temperature uniformity during battery operation is better, and the stability of battery operation is improved.

[0022] 6. The cooling and heat dissipation channels of the porous medium liquid cooling plate in the present invention can be designed according to the arrangement modes of the open-cell negative Poisson's ratio structure model and the closed-cell negative Poisson's ratio structure model, so that the cooling and heat dissipation channels can be freely designed according to the heat dissipation requirements, and the applicability is wider. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of the present invention;

[0024] Figure 2 is a schematic structural diagram of the cooperation of the open-cell and closed-cell negative Poisson's ratio unit cells in the porous medium liquid cooling plate of the present invention;

[0025] Figure 3 is a schematic structural diagram of the closed-cell negative Poisson's ratio unit cell of the present invention;

[0026] Figure 4 is a schematic structural diagram of the open-cell negative Poisson's ratio unit cell of the present invention.

[0027] In the figure, 1-battery monomer, 2-porous medium liquid cooling plate. DETAILED DESCRIPTION OF THE INVENTION

[0028] The technical solutions of the present invention will be further described in detail below with reference to the drawings:

[0029] The present invention can be implemented in many different forms and should not be considered limited to the embodiments described herein. On the contrary, these embodiments are provided so that the present disclosure is thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. In the drawings, components are enlarged for clarity.

[0030] It should be understood that although terms such as first, second, third, etc. may be used herein to describe various elements, components, and / or parts, these elements, components, and / or parts are not limited by these terms. These terms are only used to distinguish the elements, components, and / or parts from each other. Thus, the first element, component, and / or part discussed below may become the second element, component, or part without departing from the teachings of the present invention.

[0031] As Figure 1 shown, the present invention discloses a power battery cooling and protection system based on a porous medium filled with a phase change material, including N battery cells and N - 1 porous medium liquid cooling plates, where N is a natural number greater than or equal to 2;

[0032] The porous medium liquid cooling plate is in the shape of a cuboid and includes first to second heat conducting plates, first to fourth outer frames, and first to fourth inner frames. Among them, the first to second heat conducting plates have the same structure, are both rectangular, and are arranged in parallel; as Figure 2 shown, the first to fourth outer frames are sequentially and vertically fixedly connected end to end, are arranged between the first heat conducting plate and the second heat conducting plate, and are hermetically fixedly connected to the first heat conducting plate and the second heat conducting plate, so that a sealed first cavity is formed between the first to second heat conducting plates and the first to fourth outer frames; the first to fourth inner frames are sequentially and vertically fixedly connected end to end, are arranged in the first cavity, and are hermetically fixedly connected to the first heat conducting plate and the second heat conducting plate, so that a sealed second cavity is formed between the first to second heat conducting plates and the first to fourth inner frames, and a cooling flow channel is formed between the first to fourth outer frames and the first to fourth inner frames; a first through hole for coolant to flow into the cooling flow channel is provided on the first outer frame, and a second through hole for coolant to flow out of the cooling flow channel is provided on the third outer frame;

[0033] The first to fourth outer frames and the first to fourth inner frames are all formed by arranging closed - cell negative Poisson's ratio unit cells in a face - centered cubic manner; as Figure 3 shown, the closed - cell negative Poisson's ratio unit cell is an Archimedean tetrakaidecahedron, which is solid inside, and conical blind holes are provided at the centers of 8 triangular faces thereof and point to its center, and the bottom of the conical blind hole is a spherical surface protruding outward;

[0034] The cooling flow channel and the second cavity are both filled with open - cell negative Poisson's ratio unit cells arranged in a face - centered cubic manner, as Figure 4As shown, the open-cell negative Poisson's ratio unit cell is an Archimedean tetrakaidecahedron, with a spherical cavity in its center, and conical through-holes communicating with the inner spherical cavity are provided at the centers of the 8 triangular faces of the open-cell negative Poisson's ratio unit cell;

[0035] The voids between the open-cell negative Poisson's ratio unit cells in the second cavity are filled with a phase change material, and the voids between the open-cell negative Poisson's ratio unit cells in the cooling channels are filled with a cooling medium;

[0036] The battery cell is in a cuboid shape, N battery cells and N - 1 porous medium liquid cooling plates are alternately stacked in sequence, and the electrodes of the N battery modules face the same direction; the first through-holes and the second through-holes of the N - 1 porous medium liquid cooling plates are both connected to an external cooling circulation system.

[0037] The first through-hole and the second through-hole can also be filled with open-cell negative Poisson's ratio unit cells in a face-centered cubic array, and the voids between the open-cell negative Poisson's ratio unit cells are filled with a cooling medium.

[0038] As a further optimized scheme of the power battery cooling and protection system based on porous medium filled with phase change material of the present invention, the phase change material is composed of a composite of saturated fatty acids or straight-chain alkanes and expanded graphite, and its phase change temperature is 40 - 50 °C.

[0039] As a further optimized scheme of the power battery cooling and protection system based on porous medium filled with phase change material of the present invention, both the open-cell negative Poisson's ratio unit cell and the closed-cell negative Poisson's ratio unit cell are made of aluminum or aluminum alloy.

[0040] The present invention utilizes the advantages of the phase change material having a stable temperature and a high heat storage density during the solid-liquid phase change process, and can effectively improve the thermal physical properties of the power battery; the liquid cooling heat dissipation technology is currently the most effective method to solve the heat dissipation problems of electronic devices and power batteries. Filling the phase change material in the porous medium can enhance its heat transfer performance. Using the negative Poisson's ratio open structure and closed structure designed based on the same tetrakaidecahedron structure and arranged alternately to form cooling channels, and at the same time filling the phase change material in the internal high-temperature area can improve the overall heat dissipation efficiency and overall temperature uniformity of the system, and the negative Poisson's ratio characteristics presented by it can also provide a protection function for the battery pack. In addition, the porous medium liquid cooling plate is a negative Poisson's ratio structure, showing negative Poisson's ratio characteristics in three dimensions and having good anti-collision performance.

[0041] Those skilled in the art can understand that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as the general understanding of those of ordinary skill in the art to which the present invention pertains. It should also be understood that terms such as those defined in a general dictionary should be understood to have a meaning consistent with their meaning in the context of the prior art, and will not be interpreted in an idealized or overly formal sense unless defined as such here.

[0042] The specific embodiments described above further elaborate on the object, technical solution, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A power battery cooling and protection system based on a porous medium filled with a phase change material, characterized in that, It includes N battery cells and N - 1 porous medium liquid cooling plates, where N is a natural number greater than or equal to 2; The porous medium liquid cooling plate is in the shape of a cuboid and includes a first to a second heat conducting plate, a first to a fourth outer frame, and a first to a fourth inner frame. Among them, the first to the second heat conducting plates have the same structure, are both rectangular, and are arranged in parallel; the first to the fourth outer frames are successively and vertically fixedly connected end to end, are arranged between the first heat conducting plate and the second heat conducting plate, and are hermetically fixedly connected to the first heat conducting plate and the second heat conducting plate, so that a sealed first cavity is formed between the first to the second heat conducting plates and the first to the fourth outer frames; the first to the fourth inner frames are successively and vertically fixedly connected end to end, are arranged in the first cavity, and are hermetically fixedly connected to the first heat conducting plate and the second heat conducting plate, so that a sealed second cavity is formed between the first to the second heat conducting plates and the first to the fourth inner frames, and a cooling flow channel is formed between the first to the fourth outer frames and the first to the fourth inner frames; a first through hole for the coolant to flow into the cooling flow channel is provided on the first outer frame, and a second through hole for the coolant to flow out of the cooling flow channel is provided on the third outer frame; The first to the fourth outer frames and the first to the fourth inner frames are both formed by arranging closed - cell negative Poisson's ratio unit cells in a face - centered cubic manner; the closed - cell negative Poisson's ratio unit cell is an Archimedean tetrakaidecahedron, which is solid inside, and conical blind holes pointing to its center are provided at the centers of 8 triangular faces on it, and the bottom of the conical blind hole is a spherical surface protruding outward; The cooling flow channel and the second cavity are both filled with open - cell negative Poisson's ratio unit cells arranged in a face - centered cubic manner. The open - cell negative Poisson's ratio unit cell is an Archimedean tetrakaidecahedron, which has a spherical cavity in its center, and conical through holes communicating with the spherical cavity inside are provided at the centers of 8 triangular faces on the open - cell negative Poisson's ratio unit cell; The voids between the open - cell negative Poisson's ratio unit cells in the second cavity are filled with a phase - change material, and the voids between the open - cell negative Poisson's ratio unit cells in the cooling flow channel are filled with a cooling medium; The battery cell is in the shape of a cuboid. N battery cells and N - 1 porous medium liquid cooling plates are alternately stacked in sequence, and the electrodes of the N battery modules face the same direction; the first through holes and the second through holes of the N - 1 porous medium liquid cooling plates are both connected to an external cooling circulation system.

2. The power battery cooling and protection system based on a porous medium filled with a phase change material according to claim 1, wherein The phase - change material is composed of a saturated fatty acid or a composite of a straight - chain alkane and expanded graphite, and its phase - change temperature is 40 - 50 °C.

3. The power battery cooling and protection system based on a porous medium filled with a phase change material according to claim 1, characterized in that, Both the open - cell negative Poisson's ratio unit cell and the closed - cell negative Poisson's ratio unit cell are made of aluminum or aluminum alloy.

4. The power battery cooling and protection system based on a porous medium filled with a phase change material according to claim 1, wherein The first through hole and the second through hole are filled with open - cell negative Poisson's ratio unit cells arranged in a face - centered cubic manner.

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