Battery cell connection structure, battery and vehicle

Abstract

The utility model relates to the technical field of batteries, in particular to a battery cell connecting structure, a battery and a vehicle, the battery cell connecting structure comprises a first piece, a second piece, a third piece and a conversion part, the first piece can be connected with a first electrode of a first battery cell; the second bar can be connected with one of the positive electrode and the negative electrode of the adjacent second battery cell, and the polarity of the electrode connected with the second bar is opposite to that of the electrode connected with the first bar; the third chip can be connected with the second electrode of the first battery cell; the conversion part is connected with the second sheet and comprises a hot melt, and the hot melt is in a solid state at normal temperature and is heated and melted into a liquid state; and when the hot melt is changed from a solid state to a liquid state, the second bar can be disconnected from the first bar and is electrically connected with the third bar. According to the battery cell connecting structure, when the first battery cell is in thermal runaway, the thermal runaway battery cell is disconnected from the whole high-voltage loop, and meanwhile, normal connection of the high-voltage loop is ensured, so that the thermal runaway battery can continuously and stably output electric energy.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a battery core connection structure, a battery and a vehicle. Background Art

[0002] New energy vehicles, especially electric vehicles, have achieved rapid development in recent years, with sales rising year by year. However, there have also been many vehicle fire accidents caused by thermal safety accidents of battery systems. Therefore, ensuring thermal safety of battery systems has become an important prerequisite for the development and application of electric vehicles.

[0003] There are more and more thermal safety protection designs in existing battery systems. With the improvement of protection measures, it is increasingly difficult for thermal runaway of a single battery cell to cause thermal runaway of other battery cells, and safety performance is gradually improved.

[0004] However, most of the current battery systems are single cells connected in series to form a high-voltage system. When a single cell thermally runs away, the internal positive electrode melts and the cell is disconnected in the circuit. At this time, the high-voltage circuit of the battery system is disconnected, causing the battery system to no longer be able to output power. If used in a vehicle, the entire vehicle will lose its power output function. If the car is in motion at this time, the loss of power will cause a great safety hazard and cause traffic accidents. At present, there is no design in the industry that allows the battery system to continue to output power after the cell thermal runaway. Utility Model Content

[0005] The utility model provides a battery cell connection structure, a battery and a vehicle, which are used to solve the problem in the prior art that when a single battery cell thermally runs away, the battery cell will be disconnected in the circuit, resulting in a high-voltage short circuit of the battery system, and the battery system can no longer continue to output electric energy.

[0006] On the one hand, the utility model provides a battery cell connection structure, comprising:

[0007] A first tab, capable of being connected to a first electrode of a first battery cell;

[0008] The second bar piece can be connected to one of the positive and negative electrodes of the adjacent second battery cell, and the polarity of the electrode connected to the second bar piece is opposite to that of the electrode connected to the first bar piece;

[0009] A third bar can be connected to the second electrode of the first battery cell, and the first electrode has opposite polarity to the second electrode;

[0010] A conversion unit, used for switching the connection between the second bar and the first bar or the third bar;

[0011] The conversion part includes a hot melt, which is solid at room temperature and melts into a liquid state when heated; when the hot melt changes from solid to liquid, the second bar piece can be disconnected from the first bar piece and electrically connected to the third bar piece.

[0012] In some specific embodiments, the conversion unit further includes:

[0013] A moving body connected to the second bar;

[0014] A driving member connected to the moving body;

[0015] When the hot melt is in a solid state, the hot melt can prevent the moving body from moving;

[0016] When the hot melt changes from a solid state to a liquid state, the driving member can drive the moving body along a preset direction, so that the moving body is disconnected from the first bar piece and connected to the third bar piece.

[0017] In some specific embodiments,

[0018] The middle part of the moving body is slidably connected with the second bar, the first bar is located at the upper end of the moving body, and the third bar is located at the lower end of the moving body;

[0019] When the upper end of the moving body is in contact with and connected to the first bar, the second bar is electrically connected to the first bar;

[0020] When the lower end of the moving body is in contact with and connected to the third bar, the second bar is electrically connected to the third bar.

[0021] In some specific embodiments,

[0022] The moving body comprises a guide part and a limiting part, wherein the limiting part is arranged radially along the guide part; the second bar is slidably connected with the guide part;

[0023] The driving member is arranged between the limiting portion and the second bar piece, and the driving member can move along the guiding portion to cause the guiding portion and the second bar piece to move relative to each other.

[0024] In some specific embodiments,

[0025] The driving member comprises a compression spring sleeved on the guide portion, one end of the compression spring abuts against the upper end of the limiting portion, and the other end abuts against the lower end of the second bar.

[0026] In some specific embodiments,

[0027] The hot melt is filled in the gaps between the guide portion, the limiting portion, the compression spring and the second bar;

[0028] When the hot melt is in a solid state, the guide portion and the second bar remain relatively stationary;

[0029] When the hot melt is in liquid state, under the elastic force of the compression spring, the guide portion is displaced relative to the second bar, so that the moving body reaches the second position.

[0030] In some specific embodiments, it also includes:

[0031] The packaging shell, the conversion part is arranged in the packaging shell, and one end of the first bar piece, the second bar piece and the third bar piece are respectively arranged in the packaging shell.

[0032] In some specific embodiments, it also includes:

[0033] The insulator is arranged in the packaging shell, and is respectively arranged between the first bar piece and the second bar piece, and between the second bar piece and the third bar piece, so as to insulate the first bar piece, the second bar piece and the third bar piece from each other.

[0034] On the other hand, the utility model further provides a battery, comprising the battery cell connection structure provided by any of the above specific embodiments.

[0035] On the other hand, the utility model further provides a vehicle, comprising the battery provided by any of the above specific embodiments.

[0036] The beneficial effects of the utility model are as follows:

[0037] 1. The battery cell connection structure of the utility model is provided with a first bar, a second bar and a third bar. The second bar is connected to the conversion part. The first bar and the third bar can be electrically connected to the second bar through the conversion part: Under normal circumstances, the second bar is electrically connected to the first bar, and the first battery cell and the second battery cell are normally connected in series. When the first battery cell is in thermal runaway, the hot melt changes from solid to liquid due to heat, so that the second bar is disconnected from the first bar, and the second bar is electrically connected to the third bar. At this time, the first battery cell is disconnected from the second battery cell, and the high-voltage circuit of the second battery cell can also be kept normally connected. In this way, the thermal runaway battery cell can be disconnected from the entire high-voltage circuit, while ensuring the normal connection of the high-voltage circuit, so that the thermal runaway battery system can continue to output electrical energy stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of a battery cell connection structure according to an embodiment of the utility model;

[0039] Figure 2 This is a schematic diagram of a circuit connection in a battery cell of a battery cell connection structure according to an embodiment of the utility model;

[0040] Figure 3 Another circuit connection schematic diagram of a battery cell connection structure in a battery cell according to an embodiment of the utility model;

[0041] Figure 4 for Figure 1 A schematic cross-sectional view of the first battery cell along AA in a normal state;

[0042] Figure 5 for Figure 1A schematic cross-sectional view along AA of the first battery cell in the thermal runaway state;

[0043] Reference numerals:

[0044] 100 - first bar, 200 - second bar, 300 - third bar, 400 - conversion part, 410 - moving body, 411 - guide part, 412 - limiting part, 420 - driving member, 430 - hot melt, 500 - packaging shell, 600 - insulator, 700 - first battery cell, 800 - second battery cell. DETAILED DESCRIPTION

[0045] The technical solution of the utility model will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0046] As mentioned in the background technology, most of the current battery systems are single cells connected in series to form a high-voltage system. When a single cell thermally runs away, the internal positive electrode melts and the cell is disconnected in the circuit. At this time, the high-voltage circuit of the battery system is broken, causing the battery system to no longer be able to output electrical energy.

[0047] To improve the above problems, this embodiment provides a cell connection structure, such as Figure 1 As shown, it includes a first bar piece 100, a second bar piece 200, a third bar piece 300 and a conversion unit 400, wherein the first bar piece 100 can be connected to the first electrode of the first battery cell 700. The second bar piece 200 can be connected to one of the positive and negative electrodes of the adjacent second battery cell 800, and the polarity of the electrode connected to the second bar piece 200 is opposite to that of the electrode connected to the first bar piece 100. The third bar piece 300 can be connected to the second electrode of the first battery cell 700, and the second electrode has an opposite polarity to that of the first motor. It can be understood that the polarity of the electrode connected to the third bar piece 300 is the same as that of the electrode connected to the second bar piece 200.

[0048] The conversion unit 400 is connected to the second bar 200, and is used to switch the connection between the second bar and the first bar or the third bar.

[0049] The conversion part 400 includes a hot melt 430, which is solid at room temperature and melts into a liquid state when heated. When the hot melt 430 changes from solid to liquid, the second bar 200 can be disconnected from the first bar 100 and electrically connected to the third bar 300.

[0050] Specifically, the first bar sheet 100, the second bar sheet 200, and the third bar sheet 300 are made of conductive metal materials and have conductivity. In this embodiment, the first bar sheet 100 is connected to the negative electrode of the first battery cell 700, the second bar sheet 200 is connected to the positive electrode of the adjacent second battery cell 800, and the third bar sheet 300 is connected to the positive electrode of the first battery cell 700.

[0051] In a normal state, the first bar 100 is electrically connected to the second bar 200, so that the negative electrode of the first battery cell 700 is connected to the positive electrode of the second battery cell 800, so that the first battery cell 700 and the second battery cell 800 are normally connected in series. Figure 2 As shown, no current flows through the third bar 300, and the current flows into the positive electrode of the first battery cell 700, flows through the inside of the first battery cell 700, passes through the first bar 100 and the second bar 200, and flows out from the negative electrode of the first battery cell 700 to the positive electrode of the second battery cell 800, thereby realizing normal series connection between the battery cells.

[0052] In the case of thermal runaway of the first battery cell 700, the hot melt 430 changes from solid to liquid due to heat, disconnecting the second bar 200 from the first bar 100 and electrically connecting to the third bar 300, so that the positive electrode of the first battery cell 700 is directly connected to the positive electrode of the second battery cell 800. Figure 3 As shown, the current flows from the positive electrode of the first battery cell 700, through the third bar plate 300 and the second bar plate 200, and flows into the positive electrode of the second battery cell 800, disconnecting the first battery cell 700 from the high-voltage circuit of the entire battery, while maintaining the normal connection of the high-voltage circuit of the entire battery, thereby ensuring that the entire battery can continue to output electrical energy.

[0053] In some specific embodiments, the conversion unit 400 further includes a driving member 420 and a moving body 410, wherein the driving member 420 is connected to the moving body 410 and is used to drive the moving body 410 to move from the first position to the second position. Figure 4 is the first position of the moving body, Figure 5 is the second position of the moving body. When the moving body 410 is in the first position, the moving body 410 is connected to the first bar 100, so that the second bar 200 is electrically connected to the first bar 100, and the third bar 300 is in an open circuit state. When the moving body 410 is in the second position, the moving body 410 is connected to the third bar 300, so that the second bar 200 is disconnected from the first bar 100, and the second bar 200 is electrically connected to the third bar 300.

[0054] The hot melt 430 is connected to the moving body 410. The hot melt 430 is solid at room temperature and can be melted into liquid when heated in a high temperature environment. When the hot melt 430 is solid, it has a certain structural strength and can prevent the moving body 410 from moving. When the hot melt 430 is liquid, it loses its structural strength, and the driving member 420 can drive the moving body 410 in a preset direction, so that the moving body 410 moves from the first position to the second position.

[0055] Specifically, the hot melt 430 is a hot melt metal, which melts at high temperatures. The conversion part 400 is placed on the upper part of the explosion-proof valve in the first battery cell 700. Under normal circumstances, the hot melt 430 is solid, and the structural strength of the hot melt 430 itself can limit the moving body 410 and the driving member 420, so that the moving body 410 remains in the first position. When the first battery cell 700 is thermally runaway, the high-temperature ejecta of the explosion-proof valve sprays toward the conversion part 400, and the hot melt 430 melts and loses its structural strength under high temperature conditions. The hot melt 430 loses its limiting effect on the moving part and the driving member 420. Under the action of the driving member 420, the moving part moves from the first position to the second position.

[0056] In some specific embodiments, the middle of the moving body 410 is slidably connected to the second bar 200, the first bar 100 is located at the upper end of the moving body 410, and the third bar 300 is located at the lower end of the moving body 410. Figure 4 As shown, when the moving body 410 is located at the first position, the upper end of the moving body 410 is in contact with and connected to the first bar 100. Figure 5 As shown, when the moving body 410 is located at the second position, the lower end of the moving body 410 is in contact and connected with the third bar 300 .

[0057] The moving body 410 is made of a conductive metal material, and the second bar 200 is slidably connected to the moving body 410, so that the electrical connection between the second bar 200 and the moving body 410 is always maintained. Under normal conditions, the upper end of the moving body 410 is connected to the first bar 100, so that the first bar 100 is electrically connected to the second bar 200. When the first battery cell 700 thermally runs away, the moving body 410 moves downward, so that the lower end of the moving body 410 is connected to the third bar 300, and the upper end is separated from the first bar 100, so that the second bar 200 is electrically connected to the third bar 300.

[0058] In some specific embodiments, the movable body 410 includes a guide portion 411 and a limiting portion 412, the limiting portion 412 is radially arranged along the guide portion 411, the second bar 200 is slidingly connected to the guide portion 411, and the driving member 420 is arranged between the limiting portion 412 and the second bar 200. The driving member 420 can move along the guide portion 411 to cause relative displacement between the guide portion 411 and the second bar 200.

[0059] By providing the guide portion 411, the guide portion 411 is always electrically connected to the second bar 200 when sliding. By providing the limit portion 412 perpendicular to the guide portion 411, it is convenient for the driving member 420 to apply force to the limit portion 412 along the guide portion 411.

[0060] In some specific embodiments, the driving member 420 includes a compression spring sleeved on the guide portion 411, one end of the compression spring abuts against the upper end of the limiting portion 412, and the other end abuts against the lower end of the second bar 200. By arranging the compression spring between the limiting portion 412 and the second bar 200, the compression spring can be limited, so that the compression spring can be stably in a compressed state.

[0061] In some specific embodiments, the hot melt 430 is filled in the gap between the guide portion 411, the limiting portion 412, the compression spring and the second bar piece 200. When the hot melt 430 is in a solid state, the structural strength of the hot melt 430 itself can keep the compression spring stably in a compressed state, and at the same time, the guide portion 411 is fixedly connected to the second bar piece 200, so that the guide portion 411 and the second bar piece 200 remain relatively stationary. When the hot melt 430 is in a liquid state, the hot melt 430 loses its structural strength and loses the limiting function on the guide portion 411, the limiting portion 412, the compression spring and the second bar piece 200. Under the elastic force of the compression spring, the limiting portion 412 is pushed downward, and the guide portion 411 is displaced relative to the second bar piece 200, so that the moving body 410 reaches the second position.

[0062] In some specific embodiments, the cell connection structure further includes a packaging shell 500, the conversion part 400 is disposed in the packaging shell 500, and one end of the first bar piece 100, the second bar piece 200, and the third bar piece 300 are respectively disposed in the packaging shell 500. The packaging shell 500 plays a role in fixing and supporting the first bar piece 100, the second bar piece 200, the third bar piece 300 and the conversion part 400.

[0063] The packaging shell 500 can be made of high temperature resistant inorganic solid glue material to ensure structural strength and insulation.

[0064] In some specific embodiments, the battery cell connection structure also includes an insulator 600, which is disposed in the packaging shell 500. The insulator 600 is respectively disposed between the first bar piece 100 and the second bar piece 200, and between the second bar piece 200 and the third bar piece 300, and is used to insulate the first bar piece 100, the second bar piece 200 and the third bar piece 300 from each other, ensuring that the electrical connection relationship between the first bar piece 100, the second bar piece 200 and the third bar piece 300 can be realized and changed by the movable body 410.

[0065] Working principle:

[0066] Under normal circumstances, the limiting portion 412 squeezes the compression spring so that the upper contact of the guide portion 411 contacts the first bar 100, and at the same time, the solidified hot melt 430 fills the area where the guide portion 411, the limiting portion 412, the second bar 200 and the compression spring are located, so that the compression spring is stably in a compressed state, thereby allowing the guide portion 411 to stably connect the first bar 100 and the second bar 200 with high voltage. At this time, the target battery is in an effective series state.

[0067] During thermal runaway, the high-temperature eruption of the explosion-proof valve heats the conversion part 400, and the hot melt 430 melts under high temperature and loses structural strength. At this time, the compression spring pops open, driving the limit part 412 to move downward, so that the lower end contact of the guide part 411 contacts the third bar piece 300, and the upper end contact is separated from the first bar piece 100. Under the series connection of the moving body 410, the second bar piece 200 and the third bar piece 300 are connected, and at the same time, the melted part of the hot melt 430 flows into the area between the limit part 412 and the third bar piece 300. After the high temperature disappears, the hot melt 430 solidifies, realizing a reliable connection between the guide part 411 and the third bar piece 300. At this time, the thermal runaway battery cell is in a circuit-breaking state, and at the same time, the stable connection of the target battery high-voltage line can be guaranteed.

[0068] The utility model also provides a battery, including the cell connection structure provided by any of the above specific embodiments, which can ensure that the overall high-voltage circuit of the battery is normal when some of the cells are in thermal runaway, so that the battery can continue to output electrical energy stably.

[0069] The utility model also provides a vehicle, comprising the battery provided by any of the above specific embodiments. The vehicle can ensure that the overall high-voltage circuit of the battery system is normal when some cells in the battery system are in thermal runaway, so that the battery system continues to stably output electrical energy to the vehicle, so that the vehicle continues to maintain a powered driving state, and has a high safety factor.

[0070] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0071] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0072] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0073] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0074] In the present utility model, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0075] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A battery cell connection structure, characterized in that: include: A first tab, capable of being connected to a first electrode of a first battery cell; The second bar piece can be connected to one of the positive and negative electrodes of the adjacent second battery cell, and the polarity of the electrode connected to the second bar piece is opposite to that of the electrode connected to the first bar piece; A third tab, capable of being connected to the second electrode of the first battery cell, wherein the first electrode has opposite polarity to the second electrode; A conversion unit, used for switching the connection between the second bar and the first bar or the third bar; The conversion part includes a hot melt, which is solid at room temperature and melts into a liquid state when heated; when the hot melt changes from solid to liquid, the second bar piece can be disconnected from the first bar piece and electrically connected to the third bar piece.

2. The battery cell connection structure according to claim 1, characterized in that: The conversion unit also includes: A moving body connected to the second bar; A driving member connected to the moving body; When the hot melt is in a solid state, the hot melt can prevent the moving body from moving; When the hot melt changes from a solid state to a liquid state, the driving member can drive the moving body along a preset direction, so that the moving body is disconnected from the first bar piece and connected to the third bar piece.

3. The battery cell connection structure according to claim 2, characterized in that: The middle part of the moving body is slidably connected with the second bar, the first bar is located at the upper end of the moving body, and the third bar is located at the lower end of the moving body; When the upper end of the moving body is in contact with and connected to the first bar, the second bar is electrically connected to the first bar; When the lower end of the moving body is in contact with and connected to the third bar, the second bar is electrically connected to the third bar.

4. The battery cell connection structure according to claim 3, characterized in that: The moving body comprises a guide portion and a limiting portion, wherein the limiting portion is arranged radially along the guide portion; the second bar is slidably connected to the guide portion; The driving member is disposed between the limiting portion and the second bar piece, and the driving member can move along the guiding portion to cause relative displacement between the guiding portion and the second bar piece.

5. The battery cell connection structure according to claim 4, characterized in that: The driving member comprises a compression spring sleeved on the guide portion, one end of the compression spring abuts against the upper end of the limiting portion, and the other end of the compression spring abuts against the lower end of the second bar.

6. The battery cell connection structure according to claim 5, characterized in that: The hot melt is filled in the gaps between the guide portion, the limiting portion, the compression spring and the second bar; When the hot melt is in a solid state, the guide portion and the second bar remain relatively stationary; When the hot melt is in liquid state, under the elastic force of the compression spring, the guide portion is displaced relative to the second bar, so that the moving body reaches the second position.

7. The battery cell connection structure according to claim 1, characterized in that: Also includes: The conversion portion is disposed in the packaging shell, and one end of the first bar piece, the second bar piece, and the third bar piece are respectively disposed in the packaging shell.

8. The battery cell connection structure according to claim 7, characterized in that: Also includes: The insulator is arranged in the packaging shell, and is respectively arranged between the first bar piece and the second bar piece, and between the second bar piece and the third bar piece, so as to insulate the first bar piece, the second bar piece and the third bar piece from each other.

9. A battery, characterized in that: The invention comprises the battery cell connection structure according to any one of claims 1 to 8.

10. A vehicle, characterized in that: A battery comprising the battery of claim 9.

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