Visual and thermal runaway self-suppression square shell battery structure and preparation method thereof

Abstract

The invention provides a visual and thermal runaway self-suppression square shell battery structure and a preparation method, and relates to the technical field of battery design, the visual and thermal runaway self-suppression square shell battery structure comprises a square visual battery shell and a cylindrical battery shell, the cylindrical battery shell is located in the square visual battery shell, and the cylindrical battery shell is located in the square visual battery shell. The four corners of the cylindrical battery shell and the four corners of the square visual battery shell form an arc-shaped cavity with the four corners of a top cover extending downwards; observation openings are formed in the edges of the arc-shaped cavity extending downwards from the four corners of the top cover, and transparent glass sheets are embedded in the observation openings; the arc-shaped cavities extending downwards from the four corners of the top cover are divided into the inner-layer cavity and the outer-layer cavity by the aluminum plates, the inner-layer cavity is filled with the thermal-stable paraffin filler, and the outer-layer cavity is filled with the thermal-runaway-inhibiting composite paraffin filler, so that a complete square-shell battery structure capable of visualizing thermal runaway is obtained, the inner side of the inner-layer cavity is attached to the battery cell as much as possible, and the thermal runaway is prevented from being damaged. Space at four corners is reduced, stability of the battery cell is improved, and space utilization rate in the square-shell battery cell is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of battery design, and particularly to a square shell battery structure with visualization and self-suppression of thermal runaway and a preparation method thereof. Background Art

[0002] The statements in this part merely provide background technical information related to the present disclosure and do not necessarily constitute prior art.

[0003] With the rapid development of technology, as a key component for energy storage and supply, the design and manufacturing process of batteries are also constantly progressing. In modern battery manufacturing processes, the battery core is usually wound by a positive electrode, a negative electrode, and a separator. This winding structure enables the battery to obtain a higher energy density in a limited space, thereby achieving a longer battery life and higher working efficiency. However, during the winding process, due to factors such as the shape and material of the battery core housing, there are often certain spaces at the four corners.

[0004] However, due to the existence of the above spaces, a series of problems may be brought to the performance and safety of the battery. First of all, the spaces at the four corners may cause the movement and vibration of the battery core inside the housing, thus causing the risk of internal short circuit of the battery. At the same time, these spaces may also become dead zones during the charge and discharge process of the battery, affecting the energy utilization efficiency of the battery. The existing designed square shell battery structure also cannot avoid the waste of the R - corner space of the traditional square shell battery core structure and the influence of the R - corner on the performance and safety of the single - cell battery core. The stability of the battery core is poor and the space utilization rate is low. At the same time, problems such as controlling the temperature rise rate of the battery core, thermal runaway warning, and suppressing thermal runaway cannot be solved. Summary of the Invention

[0005] In order to solve the above problems, the present disclosure proposes a square shell battery structure with visualization and self - suppression of thermal runaway and a preparation method thereof. A square shell battery structure with visualized thermal runaway is designed, and a battery housing with a double - layer cavity is designed, so that the inner side of the inner cavity is as close as possible to the battery core, reducing the space at the four corners, improving the stability of the battery core, and increasing the space utilization rate inside the square shell battery core.

[0006] According to some embodiments, the present disclosure adopts the following technical solutions:

[0007] A square shell battery structure with visualization and self - suppression of thermal runaway, comprising a square visualization battery housing and a cylindrical battery housing. The cylindrical battery housing is located inside the square visualization battery housing, and an arc - shaped cavity extending downward from the four corners of the top cover is formed between the cylindrical battery housing and the four corners of the square visualization battery housing;

[0008] Observation ports are provided on the edges of the arc - shaped cavity extending downward from the four corners of the top cover, and transparent glass sheets are inlaid at the observation ports; the arc - shaped cavity extending downward from the four corners of the top cover is separated into an inner cavity and an outer cavity by an aluminum plate;

[0009] The inner cavity is filled with a first filler;

[0010] The outer cavity is filled with a second filler.

[0011] Further, the observation port is arranged at the central position of the edge of the arc-shaped cavity extending downward from the four corners of the top cover, and the observation port is in a shape with axial symmetry such as a rhombus, rectangle, circle, ellipse or triangle.

[0012] Further, a transparent glass sheet is inlaid at the observation port. The shape of the transparent glass sheet is the same as that of the observation port, and its thickness is the same as that of the square visual battery housing. The transparent glass bottle is a high borosilicate glass sheet.

[0013] Further, an arc-shaped aluminum plate is welded at the four corners of the arc-shaped cavity. The two sides of the arc-shaped aluminum plate are respectively connected to the short side and the long side of the square visual battery housing. The arc-shaped aluminum plate is close to the rounded corner radian of the finished square wound pole piece battery cell. A square aluminum plate is added in the middle of the arc-shaped cavity. The two sides of the square aluminum plate are respectively connected to the long side and the short side of the square visual battery housing to form a triangular prism space with the four corners of the square visual battery housing. The outer side separated by the square aluminum plate is the outer cavity, and the inner side is the inner cavity.

[0014] Further, the first filler is a heat-stable paraffin filler; the second filler is a thermal runaway suppression composite paraffin filler.

[0015] Further, the heat-stable paraffin filler is a paraffin material with a phase change temperature range of 35°C - 75°C, and the thermal runaway suppression composite paraffin filler is a paraffin material mixed with a temperature-sensitive color-changing powder and having a phase change temperature range of 75°C - 105°C.

[0016] Further, the area of the observation port is 0.25 cm 2 -1 cm 2 .

[0017] According to some embodiments, the present disclosure adopts the following technical solutions:

[0018] A preparation method of a visual and thermal runaway self-suppressing square shell battery structure, comprising:

[0019] The preparation method steps of the thermal runaway suppression composite paraffin filler include:

[0020] First, heat the paraffin material with a phase change temperature range of 75°C - 105°C to a liquid state, and then add a set mass of the temperature-sensitive color-changing powder accounting for the thermal runaway suppression composite paraffin into it, and stir evenly. Among them, the stirring operation is carried out at a set stirring speed and stirring time to make the temperature-sensitive color-changing powder evenly dispersed in the liquid paraffin, and the thermal runaway suppression composite paraffin is obtained after solidification.

[0021] Further, the set stirring speed is 300 rpm - 500 rpm, and the set stirring time is 1 h - 2 h.

[0022] Further, the mass of the thermosensitive discoloring powder in the composite paraffin for suppressing thermal runaway is set to 0.6 - 2.0 wt%.

[0023] Compared with the prior art, the beneficial effects of the present disclosure are as follows:

[0024] A visualized and self - suppressing thermal runaway prismatic battery structure of the present disclosure designs a square visualized battery outer shell and a cylindrical battery shell. The cylindrical battery shell is located inside the square visualized battery outer shell, and an arc - shaped cavity is formed at the four corners of the top cover where the four corners of the cylindrical battery shell extend downward. Observation ports are provided on the edges of the arc - shaped cavity where the four corners of the top cover extend downward, which can make full use of the shell space of the prismatic battery, improve the space utilization rate of the battery core, provide additional functions for the square battery core, that is, improve the thermal stability during the operation of the battery core and monitor the temperature rise situation.

[0025] A visualized and self - suppressing thermal runaway prismatic battery structure of the present disclosure divides the arc - shaped cavity where the four corners of the top cover extend downward into an inner cavity and an outer cavity by using an aluminum plate. The inner cavity is filled with a first filler, and the outer cavity is filled with a second filler. The first filler is a thermally stable paraffin filler, a thermally stable paraffin phase - change material, which can effectively control the thermal heating rate of the battery core through solid - liquid phase - change endothermic during the charge and discharge operation of the battery core, conduct the heat generated by the battery core to both sides of the battery shell, and keep the battery core operating in a lower temperature range, inhibiting side reactions caused by high - temperature operation of the battery core.

[0026] A visualized and self - suppressing thermal runaway prismatic battery structure of the present disclosure, the second filler is a composite paraffin filler for suppressing thermal runaway. The composite paraffin phase - change material for suppressing thermal runaway can, when the temperature of the battery core is in the temperature range of 75 - 105 degrees, that is, on the verge of thermal runaway of the battery core, timely suppress the thermal runaway of the battery through solid - liquid phase - change endothermic, conduct the heat to the four corners of the battery shell, increase the heat dissipation area of the battery core, and thus improve the safety of the battery.

[0027] A visualized and self - suppressing thermal runaway prismatic battery structure of the present disclosure, the thermosensitive discoloring material added to the composite paraffin for suppressing thermal runaway can change color in the thermal runaway temperature range of 75℃ - 105℃. Through the visual observation port, the thermal runaway situation of the battery and the temperature rise difference between different regions inside the battery core can be judged in a timely manner, which is conducive to more accurate failure analysis for subsequent positioning. Description of the Drawings

[0028] The accompanying drawings forming a part of this disclosure are used to provide a further understanding of the disclosure. The schematic embodiments and descriptions thereof of the disclosure are used to explain the disclosure and do not constitute an improper limitation of the disclosure.

[0029] Figure 1 Overall schematic diagram of the structure of a square shell battery with visualization and self - suppression of thermal runaway according to an embodiment of the present disclosure;

[0030] Figure 2 Side view of the structure of a square shell battery with visualization and self - suppression of thermal runaway according to an embodiment of the present disclosure;

[0031] Figure 3 Top - down schematic view of the structure of a square shell battery with visualization and self - suppression of thermal runaway according to an embodiment of the present disclosure;

[0032] Figure 4 Schematic diagram of the filling of the structure of a square shell battery with visualization and self - suppression of thermal runaway according to an embodiment of the present disclosure.

[0033] Among them, 1. Square visual battery outer shell, 2. Observation port, 3. Arc - shaped cavity, 4. Inner - layer cavity, 5. Cylindrical battery shell, 6. Outer - layer cavity, 7. Arc - shaped aluminum plate, 8. Square aluminum plate. Detailed implementation manners

[0034] The present disclosure will be further described below in conjunction with the accompanying drawings and embodiments.

[0035] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanations of the present disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present disclosure belongs.

[0036] It should be noted that the terms used herein are only for describing specific implementation manners and are not intended to limit the exemplary embodiments according to the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "include" and / or "comprise" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0037] Embodiment 1

[0038] In an embodiment of the present disclosure, a structure of a square shell battery with visualization and self - suppression of thermal runaway is provided. As Figure 1 shown, it includes a square visual battery outer shell 1 and a cylindrical battery shell 5. The cylindrical battery shell 5 is located inside the square visual battery outer shell 1. An arc - shaped cavity 3 is formed at the four corners of the cylindrical battery shell 5 and the square visual battery outer shell 1, extending downward from the four corners of the top cover, which is convenient for filling materials here. The square visual battery outer shell is a square battery core aluminum shell.

[0039] As shown Figure 2 in the figure, observation ports 2 are provided on the edges of the arc-shaped cavities 3 extending downward from the four corners of the top cover. Transparent glass sheets are inlaid at the observation ports 2; the housing space of the square shell battery can be fully utilized, the space utilization rate of the battery core can be improved, and additional functions can be provided for the square battery core, that is, the thermal stability during the operation of the battery core and the monitoring of the temperature rise situation can be improved.

[0040] As shown Figure 4 in the figure, the arc-shaped cavities extending downward from the four corners of the top cover are separated into an inner cavity 4 and an outer cavity 6 by an aluminum plate; the first filler is filled in the inner cavity 4, and the second filler is filled in the outer cavity 6, so that the inner side of the inner cavity is as close as possible to the battery core, reducing the space at the four corners and improving the stability of the battery core and the space utilization rate inside the square shell battery core.

[0041] Further, as shown Figure 2 in the figure, the observation port 2 is arranged at the central position of the edge of the arc-shaped cavity extending downward from the four corners of the top cover and is set as a rhombus. As an embodiment, the observation port can be a rhombus, rectangle, circle, ellipse or triangle with an axisymmetric characteristic shape. A transparent glass sheet is inlaid at the observation port, and the shape of the transparent glass sheet is the same as that of the observation port, and its thickness is the same as that of the square visual battery housing. The transparent glass bottle is a high borosilicate glass sheet. The high borosilicate glass can be installed by bonding or plugging, etc., and the change of the composite paraffin for suppressing thermal runaway can be observed from the outside, so as to understand the battery state.

[0042] As an embodiment, a central position on the edge of the arc-shaped cavity extending downward from the four corners of the top cover is provided with an observation port with an area of 0.25 cm 2 -1 cm 2 , and a high borosilicate glass sheet with the same shape as the observation port and the same thickness as the housing is inlaid at the observation port.

[0043] Further, as shown Figure 3 in the figure, an arc-shaped aluminum plate 7 is welded at the four corners of the arc-shaped cavity 3. The two sides of the arc-shaped aluminum plate 7 are respectively connected to the short side and the long side of the square visual battery housing 1. The arc-shaped aluminum plate 7 is close to the rounded corner radian of the finished square wound pole piece battery core. A square aluminum plate 8 is added in the middle of the arc-shaped cavity. The two sides of the square aluminum plate 8 are respectively connected to the long side and the short side of the square visual battery housing 1 to form a triangular prism space with the four corners of the square visual battery housing. The outer side separated by the square aluminum plate is the outer cavity 6, and the inner side is the inner cavity 4. This structure can fully utilize the housing space of the square shell battery, improve the space utilization rate of the battery core, and provide additional functions for the square battery core, that is, improve the thermal stability during the operation of the battery core and the monitoring of the temperature rise situation.

[0044] Further, as shown Figure 4As shown, the inner cavity 4 is filled with the first filler, and the outer cavity 6 is filled with the second filler. The first filler is a thermally stable paraffin filler, and the second filler is a thermal runaway suppression composite paraffin filler. Among them, the thermally stable paraffin filler is a paraffin material with a phase change temperature range of 35°C - 75°C, and the thermal runaway suppression composite paraffin filler is a paraffin material mixed with thermosensitive discoloring powder and having a phase change temperature range of 75°C - 105°C. The two paraffin fillers are injected into the inner and outer cavities at the four corners of the battery cell housing. A syringe or a special filling device can be used for precise filling to ensure uniform filling and no air bubble residue. Before injection, the two paraffin filling materials can be heated to a liquid state. The filling amount should be controlled according to the space size. Generally, after filling, the solid paraffin should account for 75% - 85% of the volume of the corresponding cavity, leaving a certain space for the volume expansion of the paraffin during the phase change process. Thus, the square shell battery structure with visual thermal runaway composed of various components can not only increase the stability of the battery cell but also be timely detected through the observation port when thermal runaway occurs in the battery.

[0045] As an embodiment, a square shell battery structure with visualization and self - suppression of thermal runaway is provided. Circular observation ports with an area of 0.5 cm 2 are respectively opened at the central positions of the edges of the arc - shaped cavities extending downward from the four corners of the top cover. High - borosilicate glass sheets with the same shape as the observation ports and the same thickness as the housing are inlaid at the observation ports; the inner cavity is filled with a thermally stable paraffin filler with a phase change temperature range of 40°C - 70°C, and the outer cavity of the double - cavity battery housing is filled with a thermal runaway suppression composite paraffin filler with a phase change temperature range of 80°C - 100°C, and then a complete square shell battery structure with visual thermal runaway can be obtained.

[0046] As an embodiment, a square shell battery structure with visualization and self - suppression of thermal runaway is provided. Rectangular observation ports with an area of 1 cm 2 are respectively opened at the central positions of the edges of the arc - shaped cavities extending downward from the four corners of the top cover. High - borosilicate glass sheets with the same shape as the observation ports and the same thickness as the housing are inlaid at the observation ports; the inner cavity is filled with a thermally stable paraffin filler with a phase change temperature range of 40°C - 70°C, and the outer cavity of the double - cavity battery housing is filled with a thermal runaway suppression composite paraffin filler with a phase change temperature range of 80°C - 100°C, and then a complete square shell battery structure with visual thermal runaway can be obtained.

[0047] As an embodiment, a square shell battery structure with visualization and self - suppression of thermal runaway is provided. A square shell battery structure with visualization and self - suppression of thermal runaway is provided. Circular observation ports with an area of 0.5 cm 2A circular observation port, where a high borosilicate glass sheet with the same shape as the observation port and the same thickness as the outer shell is inlaid; the inner cavity is filled with a thermally stable paraffin filler with a phase change temperature range of 35°C - 75°C, and the outer cavity of the double-layer cavity battery case is filled with a composite paraffin filler for suppressing thermal runaway with a phase change temperature range of 75°C - 105°C, and a complete square shell battery structure with visual thermal runaway can be obtained.

[0048] Example 2

[0049] In an embodiment of the present disclosure, a preparation method of a square shell battery structure with visualization and self-suppression of thermal runaway is provided. Among them, the preparation method steps of the composite paraffin filler for suppressing thermal runaway include:

[0050] First, heat the paraffin material with a phase change temperature range of 75°C - 105°C to a liquid state, and then add a set mass of thermochromic powder accounting for the composite paraffin filler for suppressing thermal runaway into it, and stir evenly. Among them, the stirring operation is carried out at a set stirring speed and stirring time to make the thermochromic powder evenly dispersed in the liquid paraffin, and the composite paraffin filler for suppressing thermal runaway is obtained after solidification.

[0051] As an embodiment, the set stirring speed is 300 rpm - 500 rpm, the set stirring time is 1 h - 2 h; the set mass of the thermochromic powder accounting for the composite paraffin filler for suppressing thermal runaway is 0.6 - 2.0 wt%.

[0052] Example 3

[0053] In an embodiment of the present disclosure, a method for self-suppression of thermal runaway of a square shell battery structure with visualization and self-suppression of thermal runaway is provided, including:

[0054] The thermal runaway structure achieves the effect of self-suppression of thermal runaway through the physical phase change of the filler in the structure. The filler is phase change paraffin. When the ambient temperature rises, this material can liquefy and absorb heat, storing the heat in the paraffin material. At the same time, the contact area between the liquefied paraffin and the battery outer wall is larger and the contact is closer, and the heat conduction efficiency is higher, so as to achieve the purpose of maintaining the normal working temperature of the battery core, that is, self-suppression of thermal runaway.

[0055] The present disclosure is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present disclosure. It should be understood that each process and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of the processes and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate for implementing the process Figure 1one or more processes and / or blocks Figure 1 means for the functions specified in one or more blocks.

[0056] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus, so that a series of operational steps are performed on the computer or other programmable apparatus to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable apparatus provide means for realizing the steps of the functions specified in one or more processes Figure 1 one or more processes and / or blocks Figure 1 steps of the functions specified in one or more blocks.

[0057] Although the foregoing has described the specific embodiments of the present disclosure in conjunction with the accompanying drawings, it is not a limitation on the protection scope of the present disclosure. Those skilled in the art should understand that, based on the technical solutions of the present disclosure, various modifications or deformations that can be made by those skilled in the art without creative efforts are still within the protection scope of the present disclosure.

Claims

1. A visualized and thermally runaway self-inhibiting prismatic battery structure, characterized in that It includes a square visual battery housing and a cylindrical battery case. The cylindrical battery case is located inside the square visual battery housing, and arc-shaped cavities extending downward from the four corners of the top cover are formed between the cylindrical battery case and the four corners of the square visual battery housing. Observation ports are provided on the edges of the arc-shaped cavities extending downward from the four corners of the top cover, and transparent glass sheets are inlaid at the observation ports. The arc-shaped cavities extending downward from the four corners of the top cover are partitioned into an inner cavity and an outer cavity by an aluminum plate. A first filler is filled in the inner cavity. A second filler is filled in the outer cavity.

2. The visualized and thermal runaway self-inhibiting prismatic battery structure according to claim 1, characterized in that, The observation ports are arranged at the central positions of the edges of the arc-shaped cavities extending downward from the four corners of the top cover, and the observation ports are in shapes with axial symmetry such as rhombus, rectangle, circle, ellipse or triangle.

3. The prismatic battery structure with visualization and self-suppression of thermal runaway as described in claim 1, characterized in that, Transparent glass sheets are inlaid at the observation ports. The shapes of the transparent glass sheets are the same as those of the observation ports, and their thicknesses are the same as the thickness of the square visual battery housing. The transparent glass bottles are high borosilicate glass sheets.

4. A prismatic battery structure with visualization and self - inhibition of thermal runaway as claimed in claim 1, wherein An arc-shaped aluminum plate is welded at the four corners of the arc-shaped cavity. The two sides of the arc-shaped aluminum plate are respectively connected to the short side and the long side of the square visual battery housing. The arc-shaped aluminum plate is close to the rounded corner radian of the finished square wound pole piece battery cell. A square aluminum plate is added in the middle of the arc-shaped cavity. The two sides of the square aluminum plate are respectively connected to the long side and the short side of the square visual battery housing to form a triangular prism space with the four corners of the square visual battery housing. The outer side separated by the square aluminum plate is the outer cavity, and the inner side is the inner cavity.

5. The visualized and thermal runaway self-suppressing prismatic battery structure according to claim 1, wherein The first filler is a thermally stable paraffin filler; the second filler is a thermal runaway suppression composite paraffin filler.

6. The visualized and thermal runaway self-inhibiting prismatic battery structure according to claim 5, wherein The thermally stable paraffin filler is a paraffin material with a phase change temperature range of 35°C - 75°C, and the thermal runaway suppression composite paraffin filler is a paraffin material mixed with a temperature-sensitive color-changing powder and having a phase change temperature range of 75°C - 105°C.

7. The square shell battery structure with visualization and self-inhibition of thermal runaway as described in claim 1, characterized in that, The area of the observation port is 0.25 cm 2 -1 cm 2 .

8. A preparation method of a prismatic battery structure with visualization and self-inhibition of thermal runaway as described in any one of claims 1-7, characterized in that, The preparation method steps of the thermal runaway suppression composite paraffin filler include: First, heat the paraffin material with a phase change temperature range of 75°C - 105°C to a liquid state, and then add a set mass of the temperature-sensitive color-changing powder accounting for the thermal runaway suppression composite paraffin into it, and stir evenly. Among them, the stirring operation is carried out at a set stirring speed and stirring time to make the temperature-sensitive color-changing powder evenly dispersed in the liquid paraffin, and the thermal runaway suppression composite paraffin is obtained after solidification.

9. The preparation method of a prismatic battery structure with visualization and self-suppression of thermal runaway as claimed in claim 8, wherein, The set stirring speed is 300 rpm - 500 rpm, and the set stirring time is 1 h - 2 h.

10. The preparation method of a prismatic battery structure with visualization and self-inhibition of thermal runaway according to claim 8, characterized in that, The set mass of the temperature-sensitive color-changing powder accounting for the thermal runaway suppression composite paraffin is 0.6 - 2.0 wt%.

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