Lithium battery case that inhibits the propagation of thermal runaway

Abstract

The application discloses a lithium battery box for inhibiting the spread of thermal runaway, which comprises a battery box body, a plurality of battery monomers and a plurality of battery grooves. The battery grooves are arranged in an array, and elastic members are connected between each row of the battery grooves. If there is only one row, the battery grooves at both ends of the row are slidably connected with the battery box body. If the number of rows is greater than or equal to two, all the battery grooves in the first row and the last row are slidably connected with the battery box body, and the battery grooves between adjacent rows are slidably connected. The battery monomers are connected in the battery grooves. The application has the beneficial effects that the separation between the runaway battery and the non-runaway battery is realized, the process of heat spreading to the normal battery is delayed, the contact area between the battery monomers and the surrounding environment is increased, the heat exchange efficiency is improved, the excess heat can be dissipated faster, the spread of thermal runaway in the battery box body can be effectively inhibited, and the safety performance of the battery system is significantly improved.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, and more particularly to a lithium battery case. Background Technology

[0002] Today, the energy crisis and environmental pollution problems are becoming increasingly severe. Therefore, electricity, as a clean energy source, is receiving increasing attention. Lithium-ion batteries, as one of the important carriers of electrical energy, are widely used in aerospace, energy storage power stations, and electric vehicles due to their advantages such as high energy density, long cycle life, and no memory effect. However, the chemical substances inside lithium-ion batteries are very reactive. Under improper use conditions such as thermal abuse and mechanical misuse, a series of exothermic reactions may occur, eventually leading to thermal runaway and the release of large amounts of heat and flammable gases. This can lead to fires or even explosions, posing a potential threat to people's lives and property. Furthermore, in practical applications, multiple batteries are usually used in battery clusters. If one battery in a cluster experiences thermal runaway, the heat may spread to adjacent batteries, triggering thermal runaway propagation and increasing the risk even further. This limits the possibility of further widespread application of lithium-ion batteries.

[0003] To address these issues, scientists and engineers are actively developing new technologies and methods to ensure the safety performance of lithium batteries. These include, but are not limited to: improving battery structure and design to enhance their resistance to thermal and mechanical abuse, thereby reducing the possibility of thermal runaway; introducing intelligent temperature monitoring and control systems to promptly detect abnormal battery temperatures and take corresponding measures, such as reducing the battery's charge and discharge rates, to prevent thermal runaway; developing safer fire-resistant materials for battery packaging and battery cluster design to isolate the spread of heat and flammable gases during thermal runaway; and establishing comprehensive intelligent monitoring systems to monitor the status of individual cells within the battery cluster in real time, promptly detecting anomalies and taking measures to prevent the spread of thermal runaway. For example, CN116742248A describes a fireproof and explosion-proof lithium battery device for fire-fighting equipment. This device features an explosion-proof shell and explosion-proof plate made of Q235 carbon steel, which is very robust and solid, isolating external fire sources. The fireproof and explosion-proof structures on all sides of the lithium battery pack provide comprehensive protection, making it safer and more reliable. However, the explosion-proof structure added to the outside of the lithium battery in this method makes the entire lithium battery very large, which does not meet the current requirements for integration and small size. Furthermore, this explosion-proof device only serves as an isolation device and cannot suppress thermal runaway that has already occurred. Alternatively, CN216311907U describes an explosion-proof and flame-retardant structure for lithium batteries, which also isolates the battery pack from the external environment, but cannot suppress the initial expansion of one or more batteries. Therefore, the above methods either struggle to overcome technical bottlenecks or incur additional resources and costs.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] The technical problem to be solved by this invention is: how to solve the problem that the current method of thermal runaway in lithium battery boxes cannot suppress thermal runaway in the early stage of expansion of one or several batteries.

[0006] The present invention solves the above-mentioned technical problems through the following technical means:

[0007] A lithium battery box for suppressing thermal runaway propagation includes a battery box body, multiple battery cells, and multiple battery slots. The battery slots are arranged in an array, and elastic elements connect each row of battery slots. If there is only one row, the two ends of the battery slots in that row are slidably connected to the battery box body. If there are two or more rows, all battery slots in the first and last rows are slidably connected to the battery box body, and the battery slots in adjacent rows are slidably connected to each other. The battery cells are connected to the battery slots.

[0008] In normal conditions, the elastic element is in its natural state, and the battery cells are located within the battery compartments. When one or more battery cells experience thermal runaway and gas rapidly accumulates, the expansion force is converted into a thrust between the battery compartments, causing them to slide and separate along the battery casing. This achieves separation between the runaway and non-runaway batteries. This design effectively reduces the contact area between the runaway and non-runaway batteries, significantly decreasing the heat transfer rate between them and thus delaying the spread of heat to the normal batteries. Simultaneously, the separation between the battery compartments increases the contact area between the battery cells and the surrounding environment, improving the heat exchange efficiency between the battery cells and the air, allowing excess heat to dissipate more quickly. Through these combined effects, this invention effectively suppresses the propagation of thermal runaway within the battery casing, significantly improving the safety performance of the battery system.

[0009] Preferably, the battery box is a rectangular cavity with an empty bottom. The bottom sides of the battery box include slide rails or grooves, and the sides of the battery slot include slide grooves or slide rails. The battery slot and the battery box are slidably connected by slide rails and slide grooves.

[0010] Preferably, the top of the battery compartment includes a battery housing cavity, the bottom of the battery cell is connected to the battery housing cavity, and the battery housing cavity and the bottom of the battery cell are in transition fit or clearance fit.

[0011] Preferably, the battery box is a rectangular cavity with a through hole in the middle. The two sides of the through hole include slide rails or grooves, and the side of the battery slot includes a groove or slide rail. The battery slot and the battery box are slidably connected by slide rails and grooves. The middle of the battery slot has a vertical through structure, and the battery cell passes through the middle through structure.

[0012] Preferably, the central through-structure of the battery slot is fitted with or has a clearance fit with the central part of the battery cell.

[0013] Preferably, the slide rail is any one of a rectangular slide rail, a dovetail slide rail, a triangular slide rail, a trapezoidal slide rail, and an arc-shaped slide rail, and the slide groove is any one of a rectangular slide groove, a dovetail slide groove, a triangular slide groove, a trapezoidal slide groove, and an arc-shaped slide groove.

[0014] In this invention, the battery housing cavity or central through-structure within each battery slot can firmly fix the individual battery cells, effectively preventing relative displacement between the battery cells and the battery slot, thus making it a unified structure. Simultaneously, the battery slot also functions to transfer the thrust generated during thermal runaway of the prismatic battery to the battery slot. This design not only provides strong support for the stability of the individual battery cells but also lays the foundation for the subsequent sliding capability of the battery slot.

[0015] Preferably, the elastic element is a spring, and the elastic element is in its natural state when the individual battery cells inside the battery box are in their natural state.

[0016] Preferably, when there are multiple elastic elements, the elastic elements are arranged in parallel at intervals.

[0017] Preferably, a receiving groove is formed on the side of the battery slot connecting elastic member, and the end portion of the elastic member is accommodated in the receiving groove.

[0018] The elastic element can be partially built into the receiving groove to reduce the distance between adjacent battery compartments in their natural state. Some expansion space can be reserved at both ends inside the battery box so that after expansion, the battery cells that have not experienced thermal runaway can move away smoothly from the battery cells that have experienced thermal runaway.

[0019] Preferably, the battery housing is made of a rigid shell.

[0020] The rigid shell design ensures that the battery cells can expand significantly in the event of thermal runaway. This characteristic applies compressive force to adjacent battery cells, thereby separating them from each other. This lays the foundation for the safe separation of subsequent battery cells in case of an accident and effectively prevents possible chain reactions.

[0021] The advantages of this invention are:

[0022] (1) Under normal conditions, the elastic element is in its natural state, and the battery cells are located inside the battery compartment. When one or more battery cells experience thermal runaway and gas rapidly accumulates, the expansion force is converted into a thrust between the battery compartments, causing the battery compartments to slide and separate along the battery casing. This achieves separation between the runaway and non-runaway batteries. This design effectively reduces the contact area between the runaway and non-runaway batteries, significantly reducing the heat transfer rate between them, thereby delaying the spread of heat to the normal batteries. At the same time, the separation between the battery compartments also increases the contact area between the battery cells and the surrounding environment, improving the heat exchange efficiency between the battery cells and the air, allowing excess heat to dissipate more quickly. Under the combined effect, this invention can effectively suppress the propagation of thermal runaway inside the battery casing and significantly improve the safety performance of the battery system.

[0023] (2) In this invention, the battery housing cavity or central through-structure within each battery slot can firmly fix the battery cells, effectively preventing relative displacement between the battery cells and the battery slot, thus making it a unified structure. Simultaneously, the battery slot also has the function of transferring the thrust generated during thermal runaway of the prismatic battery to the battery slot. This design not only provides strong support for the stability of the battery cells but also lays the foundation for the subsequent sliding capability of the battery slot;

[0024] (3) The elastic element can be partially built into the receiving groove to reduce the distance between adjacent battery slots in their natural state. Some expansion space can be reserved at both ends of the battery box so that after expansion, the battery cells that have not experienced thermal runaway can move away smoothly from the battery cells that have experienced thermal runaway.

[0025] (4) A hard shell design is adopted to ensure that the battery cells can expand significantly in the event of thermal runaway. This characteristic is used to apply pressure to adjacent battery cells, thereby achieving separation between them. This lays the foundation for the safe separation of subsequent battery cells in case of accident and effectively prevents possible chain reactions. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the lithium battery box for suppressing thermal runaway propagation according to Embodiment 1 of the present invention;

[0027] Figure 2 This is a schematic diagram of the connection between adjacent battery cells and the elastic element in Embodiment 1 of the present invention;

[0028] Figure 3 This is a top view of a multi-row, multi-cell battery cell according to Embodiment 1 of the present invention;

[0029] Figure 4 This is a schematic diagram of the lithium battery box for suppressing thermal runaway propagation according to Embodiment 2 of the present invention;

[0030] Figure 5This is a schematic diagram of the connection between adjacent battery cells and the elastic element in Embodiment 2 of the present invention;

[0031] Numbering on the map:

[0032] 1. Battery housing; 2. Battery cell; 3. Battery slot; 4. Elastic component. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1:

[0035] like Figure 1 , Figure 2 As shown, a lithium battery box for suppressing thermal runaway propagation includes a battery box body 1, multiple battery cells 2, and multiple battery slots 3. The multiple battery slots 3 are arranged in an array, and elastic members 4 connect each row of battery slots 3. If there is only one row, then the two ends or one end of each battery slot 3 in that row are slidably connected to the battery box body 1. If the number of rows is greater than or equal to two, then all battery slots 3 in the first and last rows are slidably connected to the battery box body 1, and the battery slots 3 in adjacent rows are slidably connected to each other. The battery cells 2 are connected to the battery slots 3.

[0036] like Figure 1 As shown in the illustration, this embodiment presents the case with only one row of battery slots 3, with an example of three battery slots 3 in that row. In this case, both ends of these three battery slots 3 are slidably connected to the battery housing 1 along their length. While it is possible to slide with one end of the battery slot 3 slidably connected to the battery housing 1 and the other end not in contact with it, this method results in poor stability. Therefore, it is preferable that both ends of the battery slot 3 are slidably connected to the battery housing 1.

[0037] It should be noted that if the number of rows is greater than or equal to two, all battery slots 3 in the first and last rows are slidably connected to the battery housing 1, and the battery slots 3 in adjacent rows are slidably connected to each other. Figure 3As shown, there are nine battery slots 3 horizontally and three vertically, arranged in three rows and nine columns. The first row is the first horizontal row, and the last row is the third horizontal row. In this arrangement, the tops of the nine battery slots 3 in the first horizontal row are slidably connected to the top of the battery housing 1, and their bottoms are slidably connected to the tops of the nine battery slots 3 in the second horizontal row. The bottoms of the nine battery slots 3 in the second horizontal row are slidably connected to the tops of the nine battery slots 3 in the third horizontal row, and the bottoms of the nine battery slots 3 in the third horizontal row are slidably connected to the bottom of the battery housing 1. Adjacent battery slots 3 within each horizontal row are connected by elastic members 4. The battery slots 3 at both ends of each horizontal row do not contact the battery housing 1, leaving expansion space. Of course, this embodiment can also be extended to other numbers and rectangular arrangements of battery slots 3.

[0038] like Figure 1 , Figure 2 As shown, the battery housing 1 is a rectangular cavity with an empty bottom. The bottom sides of the battery housing 1 include slide rails or grooves, and the sides of the battery slot 3 include slide grooves or slide rails. The battery slot 3 and the battery housing 1 are slidably connected via slide rails and grooves. Multiple battery slots 3 are connected as a whole by elastic members 4 and inserted into the side grooves of the battery housing 1. Once the battery cell 2 is connected to the battery slot 3, the battery slot 3 cannot slide out of the battery housing 1.

[0039] The battery compartment 3 includes a battery housing cavity at its top, and the bottom of the battery cell 2 is connected to the battery housing cavity. The battery housing cavity and the bottom of the battery cell 2 are either transitionally fitted or clearance-fitted. In this embodiment, the battery housing cavity in each battery compartment 3 can firmly fix the battery cell 2, effectively preventing relative displacement between the battery cell 2 and the battery compartment 3, making the battery compartment 3 and the battery cell 2 a single integrated structure. Simultaneously, the battery compartment 3 also has the function of transferring the thrust generated by the expansion between the battery cells 2 during thermal runaway of the prismatic battery to the battery compartment 3. This design not only provides strong support for the stability of the battery cell 2 but also lays the foundation for the subsequent sliding of the battery compartment 3.

[0040] All battery slots 3 have the same overall structure and dimensions, allowing them to slide smoothly on the sliding structure. Furthermore, the battery slots 3 can be inserted from the outside of the battery housing 1, reducing assembly difficulty. After inserting the battery slot 3, the battery cell 2 is installed inside the battery slot 3. Since the battery cell 2 is confined within the battery housing 1, the battery slot 3 will not slip out of the battery housing 1.

[0041] The slide rail can be any one of a rectangular slide rail, a dovetail slide rail, a triangular slide rail, a trapezoidal slide rail, or an arc-shaped slide rail, and the slide groove can be any one of a rectangular slide groove, a dovetail slide groove, a triangular slide groove, a trapezoidal slide groove, or an arc-shaped slide groove. Other sliding forms are also possible, such as rollers on both sides of the battery slot 3 and roller grooves on the inner side of the battery housing 1. This embodiment is not limited to sliding forms; it only requires that the battery slot 3 and the battery housing 1 be slidably connected. The slide rails, slide grooves, or other sliding mechanisms should be selected with low friction to not only meet the track requirements when the battery is separated but also reduce unnecessary friction and resistance during operation, protecting the appearance of the battery cell 2 and the battery housing 1 from damage, and reducing repair time and maintenance costs.

[0042] In this embodiment, under normal conditions, the elastic element 4 is in its natural state, and the battery cell 2 is located within the battery compartment 3. When one or more battery cells 2 experience thermal runaway and gas rapidly accumulates, the expansion force is converted into a thrust between the battery compartments 3, causing the battery compartments 3 to slide and separate along the battery housing 1. This achieves separation between the runaway and non-runaway batteries. This design effectively reduces the contact area between the runaway and non-runaway batteries, significantly reducing the heat transfer rate between them, thereby delaying the spread of heat to the normal batteries. Simultaneously, the separation between the battery compartments 3 increases the contact area between the battery cell 2 and the surrounding environment, improving the heat exchange efficiency between the battery cell 2 and the air, allowing excess heat to dissipate more quickly. Under these combined effects, this embodiment effectively suppresses the propagation of thermal runaway within the battery housing 1, significantly improving the safety performance of the battery system.

[0043] Example 2:

[0044] like Figure 4 , Figure 5 As shown, the position of battery slot 3 in this embodiment is different from that in embodiment one;

[0045] The battery housing 1 is a rectangular cavity with a through hole in the center. The two sides of the through hole include slide rails or grooves. The side of the battery slot 3 also includes a groove or slide rail. The battery slot 3 and the battery housing 1 are slidably connected via the slide rails and grooves. The battery slot 3 also has a vertical through-hole in its center, through which the battery cell 2 passes. The through-hole structure of the battery slot 3 has a transition fit or clearance fit with the center of the battery cell 2.

[0046] By placing the battery slot 3 in the middle of the battery housing 1, it is possible to apply thrust more effectively during expansion.

[0047] In the above embodiments one and two, the elastic element 4 is a spring. When the battery cells 2 inside the battery box 1 are in their natural state, the elastic element 4 is also in its natural state. When one or more battery cells 2 experience thermal runaway and the surrounding gas expands, the elastic element 4 helps to push the battery cells 2 that have not experienced thermal runaway away.

[0048] The elastic element 4 can be one or more. When there are multiple elastic elements 4, they can be arranged in parallel intervals to ensure that the battery slot 3 is subjected to uniform force.

[0049] A receiving groove can also be formed on the side of the battery slot 3 connected to the elastic member 4, and the end portion of the elastic member 4 is accommodated in the receiving groove. When the end of the elastic member 4 is built into the receiving groove, the distance between adjacent battery slots 3 in their natural state can be reduced, thereby increasing the battery capacity density inside the battery box 1.

[0050] In the above embodiments one and two, the battery housing 1 is made of a rigid shell. The rigid shell design ensures that the battery cells 2 can expand significantly in the event of thermal runaway, and this characteristic applies compressive force to adjacent battery cells 2, thereby achieving separation between them. This lays the foundation for the safe separation of subsequent battery cells 2 in unexpected situations and effectively prevents possible chain reactions.

[0051] When the battery slots 3 are in their natural state, the distance between them is small, and the elastic element 4 is relaxed, applying no force to the battery slots 3 and allowing them to move freely. However, when the battery cells 2 expand, the battery slots 3 tend to separate under the action of the elastic element 4. Due to the constraints of the slide rail and the slide groove, the battery slots 3 can only slide on the guide rail, and due to the constraint of the elastic element 4, the battery slots 3 will not remain in a state of separation. Therefore, facing the normal expansion of the battery cells 2 during normal charging and discharging, the relative displacement between the battery slots 3 is small, and even if the battery slots 3 are far away, they can still be reset by the elastic element 4 after charging and discharging. Only when the expansion of the battery cells 2 is very significant and a large expansion force is maintained will sufficient and sustained thrust be transmitted to the battery slots 3, increasing the degree of separation of the battery slots 3 and preventing them from being reset. This achieves the mechanism that the sliding of the battery slots 3 only responds to thermal runaway.

[0052] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A lithium battery box for suppressing thermal runaway propagation, characterized in that, The device includes a battery housing, multiple battery cells, and multiple battery slots arranged in an array. Elastic members connect each row of battery slots. If there is only one row, the two ends of the battery slots in that row are slidably connected to the battery housing. If there are two or more rows, all battery slots in the first and last rows are slidably connected to the battery housing, and the battery slots in adjacent rows are slidably connected to each other. The battery cells are connected within the battery slots. The battery box is a rectangular cavity with an empty bottom. The bottom sides of the battery box include slide rails or grooves, and the sides of the battery slot include slide grooves or slide rails. The battery slot and the battery box are slidably connected by slide rails and slide grooves. The battery box is a rectangular cavity with a through hole in the middle. The two sides of the through hole include slide rails or grooves. The side of the battery slot includes a groove or slide rail. The battery slot and the battery box are slidably connected by slide rails and grooves. The middle of the battery slot has a vertical through structure, through which the battery cell passes.

2. The lithium battery box for suppressing thermal runaway propagation according to claim 1, characterized in that, The top of the battery compartment includes a battery housing cavity, and the bottom of the battery cell is connected to the battery housing cavity. The battery housing cavity and the bottom of the battery cell are either transitionally fitted or clearance fitted.

3. The lithium battery box for suppressing thermal runaway propagation according to claim 1, characterized in that, The central through-structure of the battery compartment is either in a transitional or clearance fit with the central part of the battery cell.

4. The lithium battery box for suppressing thermal runaway propagation according to claim 1, characterized in that, The slide rail is any one of rectangular slide rail, dovetail slide rail, triangular slide rail, trapezoidal slide rail, and arc-shaped slide rail, and the slide groove is any one of rectangular slide groove, dovetail slide groove, triangular slide groove, trapezoidal slide groove, and arc-shaped slide groove.

5. The lithium battery box for suppressing thermal runaway propagation according to claim 1, characterized in that, The elastic element is a spring, and when the individual battery cells inside the battery box are in their natural state, the elastic element is in its natural state.

6. The lithium battery box for suppressing thermal runaway propagation according to claim 1, characterized in that, When there are multiple elastic elements, the elastic elements are arranged in parallel at intervals.

7. The lithium battery box for suppressing thermal runaway propagation according to claim 1, characterized in that, The side of the battery slot connecting the elastic member has a receiving groove, and the end portion of the elastic member is accommodated in the receiving groove.

8. The lithium battery box for suppressing thermal runaway propagation according to claim 1, characterized in that, The battery casing is made of a rigid shell.

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