Battery cell, battery module, battery pack and automobile

Abstract

The utility model discloses a battery cell, which comprises a plurality of roll cores arranged along a first direction and extending along the height direction of the battery cell; the heat conduction block is of a closed hollow structure and is provided with a peripheral wall, the heat conduction block is located between the two adjacent roll cores in the first direction, the peripheral wall of the heat conduction block is attached to the roll cores, the peripheral wall is made of a heat conduction material, and the hollow structure is filled with heat insulation fluid. By adopting the technical scheme, when the roll core generates heat in operation, the peripheral wall of the heat conduction block can quickly conduct the heat out, and meanwhile, as the hollow structure is filled with the heat insulation fluid, the heat can be effectively prevented from being transferred between the adjacent roll cores, the heat of a single roll core is prevented from being transferred to other roll cores, and the heat is prevented from being diffused. Therefore, the battery cell can be ensured to work at a proper temperature, and the safety of the battery cell is further ensured. The utility model further discloses a battery module, a battery pack and an automobile.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the battery technical field, concretely relates to a battery cell, a battery module, a battery pack and an automobile. BACKGROUND

[0002] With the rapid development of electric vehicles and the continuous expansion of its application area, the operating conditions and operating environment conditions of vehicles are increasingly complex and severe. This puts higher requirements on the power performance and safety performance of the battery. For example, under high power output, the battery (battery cell) will generate a large amount of heat, at which time the battery temperature must be kept within a reasonable range. At the same time, even in harsh environments, the battery must be ensured to be free of thermal safety risks.

[0003] To meet the energy needs of the whole vehicle, battery products are developing towards high capacity. However, the length, width and height dimensions of high-capacity batteries are large, which easily leads to internal heat accumulation and thus safety risks. Therefore, how to effectively manage heat and ensure battery safety under the conditions of high capacity, high energy and high power output is a key problem that needs to be continuously concerned and solved at present and in the future. SUMMARY

[0004] The utility model provides the following technical scheme to solve the above technical problem.

[0005] The utility model provides a battery cell, which comprises:

[0006] a plurality of winding cores arranged along a first direction, the winding cores extending along the height direction of the battery cell;

[0007] a heat-conducting block having a hollow structure and a peripheral wall, the heat-conducting block being located between two adjacent winding cores along the first direction and the peripheral wall of the heat-conducting block being attached to the winding cores, the peripheral wall being made of a heat-conducting material, and the hollow structure being filled with a heat-insulating fluid.

[0008] When the winding cores generate heat during operation, the peripheral wall of the heat-conducting block can quickly conduct the heat away. At the same time, since the hollow structure is filled with a heat-insulating fluid, the heat-insulating fluid can effectively prevent the heat from being transferred between the adjacent winding cores, thereby preventing the heat of a single winding core from being transferred to other winding cores and preventing the spread of heat. In this way, the battery cell can be ensured to work at an appropriate temperature, thereby ensuring the safety of the battery cell.

[0009] Optionally, the battery cell further comprises:

[0010] a shell extending along the height direction, the shell having a top end and a bottom end oppositely arranged along the height direction, and the plurality of winding cores being located in the shell;

[0011] a pole extending from the top end of the shell and used for collecting and transmitting the current of the battery cell to an external circuit;

[0012] a tab, leading out from the core, located between the core and the post;

[0013] a connecting piece, located in the housing, for conducting the tab and the post;

[0014] a heat-conducting block extending along a height direction, the heat-conducting block having a top end and a bottom end oppositely arranged along the height direction, the top end of the heat-conducting block having a spacing from the post, the bottom end of the heat-conducting block being in contact with a bottom end of the housing, and / or a part of the peripheral wall being in contact with two adjacent cores, at least one part of the remaining part of the peripheral wall being in contact with the housing, for conducting the heat generated by the core to the housing.

[0015] Optionally, the height of the heat-conducting block is not more than the height of the core or the height of the heat-conducting block is the same as the height of the core.

[0016] Optionally, the thickness of the peripheral wall along the first direction is d1, the peripheral wall includes a first inner side wall and a second inner side wall oppositely arranged along a direction perpendicular to the first direction, the spacing between the first inner side wall and the second inner side wall is d2, wherein 0 < d1 / d2 ≤ 1 / 2.

[0017] Optionally, 3mm ≤ d2 ≤ 6mm.

[0018] Optionally, the heat-conducting material is copper, aluminum, steel or alloy.

[0019] Optionally, the heat-insulating fluid is CO2, inert gas, air, water or fire extinguishing agent.

[0020] The utility model also provides a kind of battery module, the battery module includes multiple electric cores in any of above-mentioned embodiments, multiple electric cores are arranged along second direction, and the battery module further includes second heat-conducting block, second heat-conducting block is located between two adjacent electric cores along second direction and is in contact with electric core, second heat-conducting block is closed hollow structure, second heat-conducting block has peripheral wall, peripheral wall is heat-conducting material, and hollow structure is filled with heat-insulating fluid.

[0021] By the above technical scheme, not only the heat generated by the electric core can be conducted out in time, but also the heat transmission between adjacent electric cores can be effectively prevented, the heat diffusion is prevented, and the safety performance of the battery is improved.

[0022] The utility model also provides a kind of battery pack, the battery module includes multiple battery modules in above-mentioned embodiments, multiple battery modules are arranged along third direction, and the battery pack further includes third heat-conducting block, third heat-conducting block is located between two adjacent battery modules along third direction and is in contact with battery module, third heat-conducting block is closed hollow structure, third heat-conducting block has peripheral wall, peripheral wall is heat-conducting material, and hollow structure is filled with heat-insulating fluid.

[0023] The technical scheme has the advantages that the heat generated by the battery module can be discharged in time, and the heat is effectively prevented from transferring between adjacent battery modules, the heat diffusion is prevented, and the safety performance of the battery is improved.

[0024] The utility model further provides a car, the car includes the battery pack in above-mentioned embodiment.

[0025] The technical scheme has the advantages that the car has good safety performance. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 Show the three-dimensional structure schematic diagram of the electric core in an embodiment of the utility model Figure 1 ;

[0027] Figure 2 Show the side surface cross section view of the electric core in an embodiment of the utility model;

[0028] Figure 3 Show the front cross section view of the electric core in an embodiment of the utility model;

[0029] Figure 4 Show the three-dimensional structure schematic diagram of the electric core in an embodiment of the utility model Figure 2 ;

[0030] Figure 5 Show the three-dimensional structure schematic diagram of the electric core in an embodiment of the utility model Figure 3 ;

[0031] Figure 6 Show the three-dimensional structure schematic diagram of the heat conduction block in an embodiment of the utility model.

[0032] (Symbol explanation)

[0033] 1-electric core, 2-winding core, 3-heat conduction block, 3.1-top end of heat conduction block, 3.2-bottom end of heat conduction block, 4-housing, 4.1-top end of housing, 4.2-bottom end of housing, 5-pole, 6-tab, 7-connection piece, 8-week wall, 8.1-first inner side wall, 8.2-second inner side wall, 9-hollow structure, 10-insulating block, X-first direction, Z-height direction. DETAILED DESCRIPTION

[0034] The following describes the embodiments of the present application with specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosure. Although the description of the present application will be introduced in combination with the preferred embodiments, it does not mean that the features of the present application are limited to the embodiments. On the contrary, the purpose of introducing the present application in combination with the embodiments is to cover other options or modifications that can be extended based on the claims of the present application. In order to provide a deep understanding of the present application, many specific details will be included in the following description. The present application can also be implemented without using these details. In addition, in order to avoid confusion or obscure the focus of the present application, some specific details will be omitted in the description. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0035] The terms "first", "second", and the like are only used to distinguish description, and cannot be understood as indicating or implying relative importance.

[0036] It should be noted that in the present specification, similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0037] In order to make the purpose, technical scheme and advantages of the present application more clear, the embodiments of the present application will be further described in detail below in combination with the drawings.

[0038] During the operation of the battery cell, especially in the case of rapid charging and discharging or high ambient temperature, the winding core will generate a large amount of heat. If this heat cannot be timely discharged, it will cause the temperature of the battery cell to rise, thereby affecting the performance and service life of the battery cell, and in severe cases, it may even cause a safety accident. Based on this, the present application provides the following technical solutions to solve the above technical problems.

[0039] As shown in Figures 1-2 The present application provides a battery cell 1, which comprises:

[0040] A plurality of winding cores 2 arranged along a first direction (for example, the X direction in Figure 2 and Figure 4 The winding core 2 extends along the height direction (for example, the Z direction in Figures 2-3 of the battery cell 1;

[0041] The heat-conducting block 3 is a sealed hollow structure with a peripheral wall 8. The heat-conducting block 3 is located between two adjacent cores 2 along the first direction X, and its peripheral wall 8 is in contact with the core 2 to effectively absorb the heat generated by the core 2. The peripheral wall 8 is made of a thermally conductive material, and the hollow structure 9 is filled with a heat-insulating fluid. The function of the heat-insulating fluid is to reduce or prevent heat transfer between adjacent cores 2.

[0042] By employing the above technical solution, when the core 2 generates heat during operation, the peripheral wall 8 of the heat-conducting block 3 can quickly conduct the heat away. Simultaneously, because the hollow structure 9 is filled with insulating fluid, it effectively prevents heat transfer between adjacent cores 2, avoiding the transfer of heat from a single core 2 to other cores 2 and preventing heat diffusion. This ensures that the battery cell operates at a suitable temperature, thereby ensuring battery cell safety.

[0043] Furthermore, such as Figures 2-3 As shown, in the above embodiment, cell 1 further includes:

[0044] The housing 4 extends along the height direction Z and has a top end 4.1 and a bottom end 4.2 that are arranged opposite each other along the height direction Z. A plurality of cores 2 are located inside the housing 4.

[0045] The pole post 5 extends from the top 4.1 of the housing 4 and is used to collect the current of the cell 1 and transmit it to the external circuit.

[0046] The tab 6 is drawn from the core 2 and is located between the core 2 and the pole post 5;

[0047] The connecting piece 7, located inside the housing 4, is used to connect the tab 6 and the terminal 5 to enable current conduction. The connecting piece 7 is a metal sheet with good conductivity, such as a copper or aluminum sheet. The current generated by the winding core 2 can be transmitted through the tab 6 to the connecting piece 7, then through the connecting piece 7 to the terminal 5, and finally to the external circuit.

[0048] The heat-conducting block 3 extends along the height direction Z, and has a top end 3.1 and a bottom end 3.2 oppositely arranged along the height direction Z. The top end 3.1 of the heat-conducting block 3 is spaced apart from the pole 5, and the bottom end 3.2 of the heat-conducting block 3 is in contact with the bottom end 4.2 of the shell 4, and / or, a part of the peripheral wall 8 is in contact with the adjacent two winding cores 2, and at least one part of the remaining part of the peripheral wall 8 is in contact with the shell 4, for conducting the heat generated by the winding core 2 to the shell 4. That is, it can be that the bottom end 3.2 of the heat-conducting block 3 is in contact with the bottom end 4.2 of the shell 4, and at least one part of the remaining part of the peripheral wall 8 (not including the part in contact with the adjacent two winding cores 2) is in contact with the shell; it can also be that only the bottom end 3.2 of the heat-conducting block 3 is in contact with the bottom end 4.2 of the shell 4, and the heat generated by the winding core 2 is directly conducted to the bottom end 4.2 of the shell 4 through the heat-conducting block 3 for heat dissipation; and it can also be that only at least one part of the remaining part of the peripheral wall 8 (not including the part in contact with the adjacent two winding cores 2) is in contact with the shell 4. Specifically, which part of the remaining part is in contact with the shell 4 is not limited herein. Preferably, the bottom end 3.2 of the heat-conducting block 3 is in contact with the bottom end 4.2 of the shell 4, and a part of the peripheral wall 8 is in contact with the adjacent two winding cores 2, and the remaining part of the peripheral wall 8 is in contact with the shell 4, so that the heat dissipation effect can be improved.

[0049] According to the positional relationship of the pole 5, the tab 6, the connecting piece 7 and the heat-conducting block 3, the top end 3.1 of the heat-conducting block 3 is kept spaced apart from the pole 5, and the bottom end 3.2 of the heat-conducting block 3 is in contact with the shell 4. Through the above arrangement, on the one hand, the heat generated by the winding core 2 during operation can be directly and rapidly conducted to the shell 4 through the heat-conducting block 3, and then dissipated to the external environment through the shell 4. In this way, the accumulation of internal heat is avoided. On the other hand, since the peripheral wall of the heat-conducting block 3 is made of a heat-conducting material, such as metal, keeping a space between the top end 3.1 of the heat-conducting block 3 and the pole 5 can reduce the risk of electrical short circuit. At the same time, this space also avoids the direct contact between the heat-conducting block 3 and the connecting piece 7 or the tab 6, further preventing the occurrence of short circuit. On the other hand, the existence of the space between the top end 3.1 of the heat-conducting block 3 and the pole 5 also prevents the heat from spreading to the pole 5, avoiding the thermal damage to the pole 5, thereby significantly improving the safety and service life of the battery. Specifically, in this embodiment, the tab 6 is fixedly welded to the connecting piece 7, the connecting piece 7 is fixedly welded to the pole 5, and the pole 5 is fixedly assembled to the shell 4 through the insulating block 10.

[0050] Further, in the above embodiment, the height of the heat-conducting block 3 does not exceed the height of the winding core 2. As shown in FIG. 1, the height of the heat-conducting block 3 is less than the height of the winding core 2. In this way, the heat-conducting block 3 can be arranged in the space between the winding core 2 and the shell 4, and the heat generated by the winding core 2 can be directly and rapidly conducted to the shell 4 through the heat-conducting block 3. Figures 2-3As shown, the pole column 5, the connecting piece 7 or the tab 6 can be in contact with the heat-conducting block 3 when being pressed. Therefore, setting the height of the heat-conducting block 3 to be no more than the height of the winding core 2 can further reduce the risk of short circuit. Meanwhile, this design can also prevent the heat of the heat-conducting block 3 from being conducted to the pole column 5, the tab 6 or the connecting piece 7, thereby avoiding thermal impact on them and further improving the safety and service life of the battery.

[0051] Further, in the above embodiment, as shown in Figure 2 、 Figures 4-6 , the height of the heat-conducting block 3 is the same as the height of the winding core 2. Since the peripheral wall 8 of the heat-conducting block 3 closely adheres to the winding core 2 and the height of the heat-conducting block 3 is the same as the height of the winding core 2, it can be ensured that the heat generated by the winding core 2 can be fully absorbed and conducted by the heat-conducting block 3, thereby effectively improving the heat dissipation efficiency.

[0052] Further, as shown in Figure 2 , in the above embodiment, the thickness of the peripheral wall 8 along the first direction X is d1, the peripheral wall 8 includes a first inner side wall 8.1 and a second inner side wall 8.2 oppositely arranged along a direction perpendicular to the first direction X, and the distance between the first inner side wall 8.1 and the second inner side wall 8.2 is d2, wherein 0 < d1 / d2 ≤ 1 / 2. On the one hand, the greater the thickness d1 of the peripheral wall 8 along the first direction X, the greater the heat capacity of the heat-conducting block 3, and the more heat it can absorb and conduct; however, the greater the thickness d1, the greater the weight of the heat-conducting block 3, which is not conducive to the lightweight of the battery cell 1, which will reduce the energy density of the battery cell 1. On the other hand, the distance d2 between the first inner side wall 8.1 and the second inner side wall 8.2 determines the size of the hollow structure 9 inside the heat-conducting block 3, i.e. the capacity of the heat insulation fluid. The greater the distance d2, the greater the capacity of the heat insulation fluid, and the better the heat insulation effect of the heat-conducting block 3; however, the greater the distance d2, the greater the overall size of the heat-conducting block 3, which may occupy more internal space of the battery cell 1. Controlling d1 / d2 to be 0 < d1 / d2 ≤ 1 / 2, i.e. the thickness d1 of the peripheral wall 8 is no more than half of the distance d2 between the first inner side wall 8.1 and the second inner side wall 8.2, can balance the heat management, lightweight and space occupation. That is, it can ensure that the heat-conducting block 3 has sufficient heat capacity to absorb and conduct heat, avoid the heat-conducting block 3 being too heavy to affect the energy density of the battery cell 1, and also avoid the heat-conducting block 3 being too large in size to occupy too much internal space of the battery cell 1. The specific values of d1 and d2 can be adjusted according to the size and heat management requirements of the battery cell 1. For example, for large battery cells 1, larger values of d1 and d2 can be selected; for small battery cells 1, smaller values of d1 and d2 can be selected.

[0053] Further, in the above embodiments, 3mm≤d2≤6mm. For general battery specifications, d2 is controlled in the range of 3-6mm, which can not only ensure that the heat conduction block 3 has sufficient heat insulation effect, but also avoid the energy density of the battery cell 1 being too low due to the heat conduction block 3 being too heavy. Further, for general battery specifications, the volume of the hollow structure 9 is set to 50-90ml.

[0054] Further, in the above embodiments, the heat conduction material is copper, aluminum, steel or alloy.

[0055] Further, in the above embodiments, the heat insulation fluid is CO2, inert gas, air, water or fire extinguishing agent. Among them, gases and liquids with high specific heat capacity are selected as heat insulation fluids, such as CO2, inert gas, air and water, which can effectively balance the temperature distribution of the battery cell when the winding core generates heat, thereby preventing local overheating. Fire extinguishing agent is a substance that can suppress or extinguish fire, including water-based fire extinguishing agent, foam fire extinguishing agent, dry powder fire extinguishing agent, gas fire extinguishing agent, etc. The thermal conductivity, density and specific heat capacity of the fire extinguishing agent depend on its specific composition and state. The main advantage of the fire extinguishing agent is its fire extinguishing function, which can suppress the flame when the battery cell is in thermal runaway, thereby improving the safety of the battery cell. In particular, when CO2 is selected as the heat insulation fluid, not only can it effectively insulate heat, but also can quickly extinguish the fire when the battery cell is in thermal runaway. In addition, as a gas, CO2 can also play a role in elastic buffering when the battery cell is subjected to impact or battery swelling, preventing mechanical damage caused by pressing the battery pole piece, further enhancing the safety protection performance of the battery cell. Further, the gas pressure in the hollow structure 9 is 0.05-0.2Mpa. Such a gas pressure setting can not only improve the heat insulation effect, but also ensure that there is enough amount of fire extinguishing gas to quickly respond to potential safety risks when thermal runaway occurs.

[0056] The utility model also provides a kind of battery module, the battery module includes multiple any one of above-mentioned embodiments in battery cell 1, multiple battery cell 1 is arranged along second direction, and the battery module further includes second heat conduction block, second heat conduction block is located between two adjacent battery cells along second direction and is attached with battery cell, second heat conduction block is closed hollow structure, second heat conduction block has perimeter wall, and the perimeter wall of second heat conduction block is heat conduction material, and the hollow structure of second heat conduction block is filled with heat insulation fluid. Wherein, second direction is arbitrary direction. Second direction can be same with the first direction X in each of the above embodiments, and also can be different with the first direction X in each of the above embodiments.

[0057] The technical scheme has the advantages that not only can the heat generated by the battery cell be discharged in time, but also the heat can be effectively prevented from transferring between adjacent battery cells, the heat diffusion is prevented, and the safety performance of the battery is improved.

[0058] The utility model also provides a battery pack, the battery module includes a plurality of above -mentioned electric battery module in the embodiment, a plurality of battery modules arrange along third direction, the battery pack also includes third heat conducting block, third heat conducting block is located between two adjacent battery modules and is pasted with battery module along third direction, third heat conducting block is closed hollow structure, third heat conducting block has the circumferential wall, the circumferential wall of third heat conducting block is heat conducting material, and the hollow structure of third heat conducting block is filled with heat insulation fluid, wherein, third direction is arbitrary direction.

[0059] The technical scheme has the advantages that not only can the heat generated by the battery cell be discharged in time, but also the heat can be effectively prevented from transferring between adjacent battery cells, the heat diffusion is prevented, and the safety performance of the battery is improved.

[0060] The utility model also provides a car, the car includes above -mentioned battery pack in the embodiment.

[0061] The technical scheme has the advantages that not only can the heat generated by the battery cell be discharged in time, but also the heat can be effectively prevented from transferring between adjacent battery cells, the heat diffusion is prevented, and the safety performance of the battery is improved.

[0062] Although the utility model has been illustrated and described with reference to certain preferred embodiments thereof, it should be understood that the above description is further detailed explanation of the utility model in combination with specific embodiments, and the specific implementation of the utility model should not be limited to these descriptions. Those skilled in the art can make various changes in form and details, including making a number of simple derivations or replacements, without departing from the spirit and scope of the utility model.

Claims

1. An electric cell, characterized by, The battery module comprises: a plurality of winding cores arranged along a first direction, the winding cores extending along a height direction of the winding core; a heat-conducting block having a hollow structure and a peripheral wall, the heat-conducting block being located between two adjacent winding cores along the first direction and the peripheral wall of the heat-conducting block being in contact with the winding cores, the peripheral wall being made of heat-conductive material, and the hollow structure being filled with heat-insulating fluid.

2. The electric cell of claim 1, wherein, Further comprising: a shell extending along the height direction, the shell having a top end and a bottom end arranged oppositely along the height direction, and the plurality of winding cores being located in the shell; a pole extending from the top end of the shell for collecting and transmitting current of the winding core to an external circuit; a tab extending from the winding core and located between the winding core and the pole; a connecting sheet located in the shell for conducting the tab and the pole; the heat-conducting block extending along the height direction, the heat-conducting block having a top end and a bottom end arranged oppositely along the height direction, the top end of the heat-conducting block being spaced apart from the pole, the bottom end of the heat-conducting block being in contact with the bottom end of the shell, and / or a part of the peripheral wall being in contact with the two adjacent winding cores, and at least one part of the remaining part of the peripheral wall being in contact with the shell for conducting heat generated by the winding core to the shell.

3. The electric cell of claim 2, wherein, The height of the heat-conducting block is not more than the height of the winding core or the height of the heat-conducting block is the same as the height of the winding core.

4. The electric cell of claim 1, wherein, The thickness of the peripheral wall along the first direction is d1, the peripheral wall comprises a first inner side wall and a second inner side wall arranged oppositely along a direction perpendicular to the first direction, and the distance between the first inner side wall and the second inner side wall is d2, wherein 0 5. The electric cell of claim 4, wherein, 3mm≤d2≤6mm.

6. The electric cell of claim 1, wherein, The heat-conductive material is copper, aluminum, steel or alloy.

7. The electric cell of claim 1, wherein, The heat-insulating fluid is CO2, inert gas, air, water or fire extinguishing agent.

8. A battery module, characterized by The battery module comprises a plurality of winding cores arranged along a first direction, the winding cores extending along a height direction of the winding core, and a heat-conducting block having a hollow structure and a peripheral wall, the heat-conducting block being located between two adjacent winding cores along the first direction and the peripheral wall of the heat-conducting block being in contact with the winding cores, the peripheral wall being made of heat-conductive material, and the hollow structure being filled with heat-insulating fluid.

9. A battery pack, characterized by, The battery module comprises a plurality of winding cores arranged along a first direction, the winding cores extending along a height direction of the winding core, and a heat-conducting block having a hollow structure and a peripheral wall, the heat-conducting block being located between two adjacent winding cores along the first direction and the peripheral wall of the heat-conducting block being in contact with the winding cores, the peripheral wall being made of heat-conductive material, and the hollow structure being filled with heat-insulating fluid.

10. An automobile characterized by comprising: The battery module comprises a plurality of winding cores arranged along a first direction, the winding cores extending along a height direction of the winding core, and a heat-conducting block having a hollow structure and a peripheral wall, the heat-conducting block being located between two adjacent winding cores along the first direction and the peripheral wall of the heat-conducting block being in contact with the winding cores, the peripheral wall being made of heat-conductive material, and the hollow structure being filled with heat-insulating fluid.

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