Battery cell capable of monitoring operation pressure in real time, cylindrical battery, battery pack and automobile

Abstract

The utility model discloses a battery cell capable of monitoring operation pressure in real time, a cylindrical battery, a battery pack and an automobile, the battery cell comprises a roll core, and the roll core is formed by winding one side edge of a battery pole piece towards the other side opposite to the side edge; the number of the flexible sensors is at least two, the flexible sensors are located at the positions with different radiuses away from the center of the roll core, and one side face of each flexible sensor is in a circular arc shape attached to the roll core; wherein the battery pole piece in the roll core is disconnected at the position where the flexible sensor is arranged, two opposite side edges of the flexible sensor are connected with two side edges of the disconnected position of the battery pole piece respectively, and the flexible sensor is attached to the cambered surface of the battery pole piece located on the inner side of the flexible sensor. The pressure data acquired by the flexible sensor is more accurate, the pressure at different positions in the cylindrical battery can be acquired, the internal pressure distribution data of the roll core can be acquired, and the internal force field distribution of the cylindrical battery can be constructed. The relationship between the pressure and the battery life is used for predicting the service life of the cylindrical battery.

Description

Technical Field

[0001] The utility model relates to the technical field of battery safety, and more specifically, to a battery cell, a cylindrical battery, a battery pack and a car capable of monitoring operating pressure in real time. Background Art

[0002] In recent years, lithium-ion batteries have been widely used in the electric vehicle market, and electric vehicles using cylindrical lithium-ion batteries have occupied a large market share. Unlike square shells and soft packs, cylindrical batteries are difficult to capture their overall operating pressure during operation due to their curved arc surface structural characteristics. The difficult-to-obtain operating pressure data is not conducive to the study of the internal force transmission mechanism of cylindrical cells, and is not conducive to the optimal strength design of cylindrical shells, which can easily lead to over-design.

[0003] There is a close connection between the pressure and life of the battery during its life cycle, and they show a positive correlation. When the battery life decays faster, the corresponding pressure also shows the same trend of accelerated growth. When the battery is running stably, its pressure changes are relatively stable and no major mutations occur. The health of the battery can be assessed by the changing trend of the pressure, and the real-time health monitoring of the battery can be achieved by the real-time value and outlier degree of the pressure. In addition, for extreme conditions such as thermal runaway, early detection and early response can be achieved by monitoring the changes in pressure, further reducing possible safety risks. Therefore, it is very necessary to obtain the operating pressure data in cylindrical batteries. Utility Model Content

[0004] The utility model provides a battery cell, a cylindrical battery, a battery pack and a car capable of monitoring operating pressure in real time, solving the problem of how to more accurately obtain operating pressure data in a cylindrical battery and obtain the pressure at different positions of a winding core.

[0005] In order to achieve the above-mentioned purpose, the technical solution provided by the utility model is:

[0006] A battery cell capable of real-time monitoring of operating pressure, comprising:

[0007] A winding core is formed by winding one side of the battery electrode toward the other side opposite to the side;

[0008] At least two flexible sensors are provided, each of which is located at a different radius from the center of the winding core, and a side surface of each of the flexible sensors is in an arc shape that fits the winding core;

[0009] The battery electrode inside the winding core is disconnected at the location where the flexible sensor is set, and the two opposite sides of the flexible sensor are respectively connected to the two sides of the disconnected location of the battery electrode, and the flexible sensor is attached to the arc surface of the battery electrode located on its inner side.

[0010] Furthermore, one side of the flexible sensor located on the outside of the winding core is connected to the side of the battery electrode sheet, and the flexible sensor is attached to the arc surface of the battery electrode sheet located on the inside thereof.

[0011] Furthermore, the length of the flexible sensor is consistent with the height of the winding core.

[0012] Further, when the flexible sensors are arranged in an even number, two adjacent flexible sensors are located on opposite sides of the center line of the winding core.

[0013] Further, when the flexible sensors are arranged in an odd number, adjacent flexible sensors are arranged in an array around the center line of the winding core.

[0014] Furthermore, the flexible sensor is connected to the outside through a wire.

[0015] Furthermore, the flexible sensor is connected to the outside via wireless transmission.

[0016] The utility model also provides a cylindrical battery, comprising the battery core capable of real-time monitoring of operating pressure, a shell located outside the winding core, and cover plates located at both ends of the winding core.

[0017] The utility model also provides a battery pack, comprising a controller, a battery box and a plurality of cylindrical batteries, wherein the cylindrical batteries are located in the battery box, and the flexible sensor is also connected to the controller.

[0018] The utility model also provides a car, comprising a car body and the battery pack, wherein the battery pack is arranged in the car body.

[0019] Compared with the prior art, the technical solution provided by the utility model has the following beneficial effects:

[0020] By setting flexible sensors at different positions in the winding core, and the battery pole piece inside the winding core is disconnected at the flexible sensor, the two opposite sides of the flexible sensor are respectively connected to the two sides of the disconnected battery pole piece, and the flexible sensor is attached to the arc surface of the battery pole piece located inside it, so that the pressure data obtained by the flexible sensor is more accurate. During the operation of the cylindrical battery, the internal pressure change of the battery during the operation is obtained. Through the pressure change, on the one hand, the pressure distribution law of different parts during the operation of the cylindrical battery can be analyzed for the evaluation of the battery health status. On the other hand, the extreme pressure at the end of the battery life can provide data support for the strength design of the battery to avoid over-design. In addition, the acquisition of the extreme pressure also provides guidance for the design of new batteries with large pressure changes during the charge and discharge cycle, such as silicon-carbon negative electrode lithium-ion batteries, solid-state lithium-ion batteries, etc. Compared with traditional cylindrical batteries, by implanting flexible sensors, the operating mechanism of cylindrical batteries is further studied, the battery is more intelligent, the design is more reasonable, and the use is safer, which escorts the wider application of cylindrical batteries and is easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a graph showing the relationship between the operating pressure in the battery and the battery life;

[0022] Figure 2 This is a schematic diagram of the cylindrical battery structure;

[0023] Figure 3 Schematic diagram of cylindrical battery structure;

[0024] Figure 4 Set up a location diagram for the external flex sensor;

[0025] Figure 5 Schematic diagram of the winding core structure;

[0026] Figure 6 Diagram of setting the position for the middle flex sensor.

[0027] Description of labels:

[0028] 1. Lower cover; 2. Shell; 3. Winding core; 4. Flexible sensor; 4-1. External flexible sensor; 4-2. Middle flexible sensor; 5. Upper cover. DETAILED DESCRIPTION

[0029] In order to further understand the content of the utility model, the utility model is described in detail in conjunction with the drawings and embodiments.

[0030] The structures, proportions, sizes, etc. illustrated in the drawings of the present utility model are only used to match the contents disclosed in the specification so as to be understood and read by people familiar with the technology. They are not used to limit the restrictive conditions for the implementation of the present utility model, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present utility model without affecting the effects and purposes that can be achieved by the present utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on used in the present utility model are only for the convenience of description, and are not used to limit the scope of implementation. The change or adjustment of the relative relationship should also be regarded as the scope of implementation of the present utility model without substantial changes in the technical content.

[0031] like Figure 1 As shown, during the life cycle of the battery, there is a close connection between its internal pressure and its life, so obtaining the internal pressure data of the battery is very important for predicting the battery life and for monitoring the battery health. In the previous internal pressure test method of cylindrical batteries, the flexible sensor is usually set inside the cylindrical battery core. The core of the cylindrical battery is usually formed by winding one side of the battery electrode toward the other side opposite to the side. In this case, after the cylindrical battery core is formed, the position where the flexible sensor is set will have a certain thickness difference relative to other positions. When the cylindrical battery expands during the charging and discharging process, the position where the flexible sensor is set will be squeezed to a greater extent, which will cause an error between the pressure data detected by the flexible sensor and the actual internal pressure data of the cylindrical battery, resulting in inaccurate pressure data obtained.

[0032] like Figure 4 , Figure 5 and Figure 6 As shown, this embodiment provides a battery cell that can monitor the operating pressure in real time, and can obtain more accurate internal pressure data of the cylindrical battery.

[0033] The battery cell in this embodiment includes a winding core 3 and a flexible sensor 4. The winding core 3 is cylindrical, and is formed by winding one side of the battery pole piece toward the other side opposite to the side. The battery pole piece in the cylindrical winding core 3 is arc-shaped, which makes it difficult to capture the battery pressure inside the battery. By setting the flexible sensor 4 and attaching it to the arc side of the battery pole piece in the winding core 3, more accurate battery internal pressure data can be obtained.

[0034] Specifically, at least two flexible sensors 4 are arranged, one side of which is in an arc shape fitting with the core 3, and they are respectively located at positions of different radii from the center of the core 3, so as to obtain pressure data at different positions in the core 3, thereby obtaining the internal pressure distribution data of the core 3, constructing the internal force field distribution of the cylindrical battery, and used for analyzing the pressure distribution law of different parts during the operation of the cylindrical battery, and through the relationship between pressure and battery life, used for predicting the operating life of the cylindrical battery.

[0035] In this embodiment, two flexible sensors 4 are provided. Of course, in other embodiments, the number of flexible sensors 4 is not limited and is determined according to the required amount of pressure data. In this embodiment, one flexible sensor 4 is provided inside the winding core 3, and the other flexible sensor 4 is provided outside the winding core 3.

[0036] Recombination Figure 6 As shown, the flexible sensor 4 located inside the winding core 3 is the middle flexible sensor 4-2. At the location where the middle flexible sensor 4-2 is located, the battery pole piece is disconnected at this location. The two opposite straight sides of the middle flexible sensor 4-2 are respectively connected to the two straight sides where the battery pole piece is disconnected, and the middle flexible sensor 4-2 is attached to the arc surface of the battery pole piece located inside it. This avoids the battery pole piece in the winding core 3 being subjected to a large extrusion force at the location where the middle flexible sensor 4-2 is located after the battery pole piece is wound, so that the pressure data detected by the middle flexible sensor 4-2 is more accurate.

[0037] Recombination Figure 4 As shown, the flexible sensor 4 located outside the winding core 3 is an external flexible sensor 4-1, and a straight side of the external flexible sensor 4-1 is connected to the straight side of the battery pole piece, and the external flexible sensor 4-1 is attached to the arc surface of the battery pole piece located inside it. After the winding core 3 is assembled into a cylindrical battery, the other side of the external flexible sensor 4-1 is against the shell 2 of the cylindrical battery. When the cylindrical battery expands, the flexible sensor 4 cooperates with other components of the battery, and through the principle of action and reaction, the flexible sensor 4 monitors the internal pressure signal of the winding core in real time.

[0038] As a further improvement, the length of the flexible sensor 4 is consistent with the height of the winding core 3, so that the flexible sensor 4 is attached to the entire height of the cylindrical battery, and the pressure data can be detected more accurately. Figure 2 To explain, Figure 2 The up-down direction in the illustration direction is the length direction of the flexible sensor 4 and the height direction of the winding core 3 .

[0039] In some cases, the flexible sensors 4 are arranged in an even number. In this case, two adjacent flexible sensors 4 are located on opposite sides of the center line of the winding core 3, so that the pressure data detected by the two adjacent flexible sensors 4 can be compared, thereby detecting more accurate pressure data.

[0040] In other cases, the flexible sensors 4 are arranged in an odd number. In this case, the adjacent flexible sensors 4 are arranged in an array around the center line of the winding core 3, so that the pressure data detected by the adjacent flexible sensors 4 can be compared.

[0041] Combination Figure 2 and Figure 3 As shown, the utility model also provides a cylindrical battery, including the above-mentioned battery cell capable of real-time monitoring of operating pressure, a shell 2 and a cover plate. The winding core 3 is located in the shell 2, and the two ends of the shell 2 have openings, and covers are arranged at the openings, namely, a lower cover plate 1 and an upper cover plate 5, which serve as a positive electrode cover plate and a negative electrode cover plate, respectively. Electrolyte is filled in the cylindrical battery, and the flexible sensor 4 is made of a material resistant to electrolyte corrosion.

[0042] The utility model also provides a battery pack, including a controller, a battery box and a plurality of the above cylindrical batteries, wherein the cylindrical batteries are located in the battery box, and the flexible sensor 4 is also connected to the controller. The controller in this embodiment is a control unit in a battery management system, and the flexible sensor 4 is connected to the controller by wire or wireless transmission.

[0043] The utility model also provides a car, comprising a car body and the battery pack, wherein the battery pack is arranged in the car body.

[0044] It can be seen from the above description that the utility model sets a flexible sensor 4 in the winding core 3 so that the flexible sensor 4 is attached to the battery pole piece in the winding core 3, and the battery pole piece is disconnected at the position where the flexible sensor 4 is set inside the winding core 3, so that the pressure data detected by the flexible sensor 4 is more accurate; and the flexible sensor 4 is set at different positions in the winding core 3, so that the pressure data at different positions in the winding core 3 can be detected, the internal force field distribution of the cylindrical battery can be constructed, and the operating life of the cylindrical battery can be predicted through the relationship between the battery pressure and the battery life. In addition, the operating limit pressure of the cylindrical battery can be obtained, which provides a reference for the structural strength design of the cylindrical battery and the selection of shell component materials.

[0045] The above schematically describes the present invention and its implementation methods, which are not restrictive. The drawings show only one implementation method of the present invention, and the actual structure is not limited thereto. Therefore, if ordinary technicians in this field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A battery cell capable of real-time monitoring of operating pressure, characterized in that: include, A winding core (3) is formed by winding one side edge of the battery electrode sheet toward another side opposite to the side edge; At least two flexible sensors (4) are provided, each of which is located at a position with a different radius from the center of the winding core (3), and a side surface of each of the flexible sensors (4) is in an arc shape that fits the winding core (3); The battery electrode sheet inside the winding core (3) is disconnected at the location where the flexible sensor (4) is provided, and two opposite side edges of the flexible sensor (4) are respectively connected to two side edges at the location where the battery electrode sheet is disconnected, and the flexible sensor (4) is attached to the arc surface of the battery electrode sheet located on its inner side.

2. The battery cell capable of real-time monitoring of operating pressure according to claim 1, characterized in that: One side edge of the flexible sensor (4) located outside the winding core (3) is connected to the side edge of the battery electrode sheet, and the flexible sensor (4) is attached to the arc surface of the battery electrode sheet located inside the flexible sensor (4).

3. The battery cell capable of real-time monitoring of operating pressure according to claim 1 or 2, characterized in that: The length of the flexible sensor (4) is consistent with the height of the winding core (3).

4. The battery cell capable of real-time monitoring of operating pressure according to claim 3, characterized in that: When the flexible sensors (4) are arranged in an even number, two adjacent flexible sensors (4) are located on opposite sides of the center line of the winding core (3).

5. The battery cell capable of real-time monitoring of operating pressure according to claim 3, characterized in that: When the flexible sensors (4) are arranged in an odd number, adjacent flexible sensors (4) are arranged in an array around the center line of the winding core (3).

6. The battery cell capable of real-time monitoring of operating pressure according to claim 1, characterized in that: The flexible sensor (4) is connected to the outside via a wire.

7. The battery cell capable of real-time monitoring of operating pressure according to claim 1, characterized in that: The flexible sensor (4) is connected to the outside via wireless transmission.

8. A cylindrical battery, characterized in that: It comprises the battery cell capable of real-time monitoring of operating pressure as claimed in any one of claims 1 to 7, a shell (2) located outside the winding core (3), and cover plates located at both ends of the winding core (3).

9. A battery pack, characterized in that: It comprises a controller, a battery box and several cylindrical batteries as claimed in claim 8, wherein the cylindrical batteries are located in the battery box, and the flexible sensor (4) is also connected to the controller.

10. An automobile, characterized in that: The invention comprises a vehicle body and the battery pack according to claim 9, wherein the battery pack is arranged in the vehicle body.

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