Explosion-proof battery housing and lithium battery
By using a separator plate and explosion-proof valve design, the lithium battery can be depressurized in stages under abnormal conditions. Combined with mechanical circuit disconnection and PTC thermistor protection, the safety hazard of lithium battery explosion is solved, achieving rapid depressurization and low maintenance costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HEFEI GUOXUAN HIGH TECH POWER ENERGY
- Filing Date
- 2025-06-16
- Publication Date
- 2026-06-23
Smart Images
Figure CN224400588U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of lithium battery technology, and in particular to an explosion-proof battery casing and a lithium battery. Background Technology
[0002] Lithium-ion batteries may experience thermal runaway under abnormal conditions such as overcharging, over-discharging, short circuits, or high temperatures, leading to a rapid increase in internal pressure and potentially even an explosion. Therefore, designing a casing structure that can effectively prevent battery explosions is of great significance for improving the safety of lithium-ion batteries.
[0003] For example, Chinese patent document (publication number: CN 116315320 A) discloses an explosion-proof structure for a lithium battery casing and an explosion-proof battery casing for a lithium battery. The explosion-proof structure includes a recessed area on the outer surface of the casing and a puncture line on the bottom surface of the recessed area. The puncture line has a V-shaped cross-section. The recessed area is manufactured using a stamping process. The ends of the puncture line are not connected; the puncture line forms an explosion-proof sheet within the recessed area, and the connecting line between the ends of the puncture line is the bending line of the explosion-proof sheet. When this explosion-proof structure is applied inside a battery casing, when the explosion-proof sheet is subjected to pressure, it breaks along the tip of the puncture line and folds away from the inner surface of the casing, thereby effectively relieving pressure.
[0004] However, the air pressure when the explosion-proof sheet is ruptured can also pose a significant safety hazard to other components in the surrounding area of the battery.
[0005] The relevant technologies do not provide effective solutions to the above problems. Utility Model Content
[0006] The main purpose of this invention is to provide an explosion-proof battery casing and a lithium battery, aiming to at least solve the technical problem of pressure shock caused by the outward leakage of battery pressure in related technologies.
[0007] To achieve the above objectives, this utility model proposes an explosion-proof battery housing, comprising: a housing body with a partition plate fixedly connected inside, one side of the partition plate being a battery compartment and the other side being an isolation compartment; the housing body having a pressure relief hole connecting to the outside and the isolation compartment; an explosion-proof valve connected to the partition plate, the explosion-proof valve including a connecting frame and an explosion-proof partition; the connecting frame being fixedly connected to the partition plate; the explosion-proof partition being fixedly connected to the connecting frame, at least a portion of the explosion-proof partition being able to disconnect and rotate under pressure; and a cover plate connected to the housing body, the cover plate being used to seal the isolation compartment; wherein, when the pressure value inside the battery compartment exceeds a preset pressure value, at least a portion of the explosion-proof partition is able to disconnect and rotate toward the isolation compartment, so that the isolation compartment communicates with the battery compartment.
[0008] In one embodiment of this utility model, the surface where the pressure relief hole is located is to the side of the surface where the explosion-proof partition is located.
[0009] In one embodiment of this utility model, the explosion-proof partition has a first groove and a second groove on the side near the isolation chamber. The first groove is elongated and perpendicular to one side wall of the shell body. The second groove is formed along the connection line between the explosion-proof partition and the connecting frame, and the depth of the second groove is greater than that of the first groove. The explosion-proof partition and the connecting frame can break at the second groove, so that the area enclosed by the second groove and the first groove can rotate along the first groove toward the isolation chamber.
[0010] In one embodiment of this utility model, two explosion-proof valves are provided, and the two explosion-proof valves are symmetrically arranged on the partition plate.
[0011] In one embodiment of this utility model, a plurality of isolation ribs perpendicular to the bottom plate of the shell body are fixedly connected to the inner wall of the shell body located in the battery compartment.
[0012] In one embodiment of this utility model, a positive terminal and a negative terminal are connected to the partition plate, and a first terminal and a second terminal are connected to the cover plate;
[0013] The first terminal is electrically connected to the positive terminal, and the second terminal is electrically connected to the negative terminal.
[0014] In one embodiment of this utility model, a positive temperature coefficient thermistor is further included, which is located between the first terminal and the positive terminal, and between the second terminal and the negative terminal.
[0015] In one embodiment of this utility model, the first terminal and the second terminal are slidably connected to the cover plate, and a spring piece is fixedly connected to the end of the first terminal and the second terminal located in the isolation chamber, and the spring piece is fixedly connected to the cover plate.
[0016] In one embodiment of the present invention, a first snap-fit block is fixedly connected to the inner wall of the shell body, and a second snap-fit block is fixedly connected to the cover plate, wherein the first snap-fit block and the second snap-fit block snap-fit together.
[0017] When the first locking block and the second locking block are locked together, the spring is in a compressed state.
[0018] This utility model also provides a lithium battery, which includes: an explosion-proof battery housing as described above; and a battery pack; wherein the battery pack is located inside the battery compartment.
[0019] Compared with the prior art, the technical solution provided by this utility model has the following advantages:
[0020] (1) The explosion-proof battery casing and lithium battery of this utility model reduce the risk of deflagration by step-by-step pressure relief, that is, the explosion-proof partition first opens the isolation chamber for buffering, and then discharges in a directional manner through the pressure relief hole.
[0021] (2) The explosion-proof battery casing and lithium battery of this utility model have the pressure relief hole located on the side of the explosion-proof partition, so that after the gas is released from the explosion-proof partition, the gas will not directly rush to the pressure relief hole, but will be fully buffered in the isolation chamber and then released from the pressure relief hole to further prevent explosion.
[0022] (3) The explosion-proof battery shell and lithium battery of this utility model have a first snap-fit block fixedly connected to the inner wall of the shell body and a second snap-fit block fixedly connected to the cover plate, and the first snap-fit block and the second snap-fit block snap-fit together; when the first snap-fit block and the second snap-fit block snap-fit together, the spring is in a compressed state, which realizes electrical self-isolation, and the mechanical circuit is disconnected by pressure triggering, resulting in a very fast response time and structural reusability. After depressurization, the explosion-proof valve can be replaced to restore use, reducing maintenance costs. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0024] Figure 1 This is a three-dimensional structural diagram of an explosion-proof battery housing according to an embodiment of the present invention;
[0025] Figure 2 A three-dimensional structural diagram of an explosion-proof battery housing according to one embodiment of the present invention is shown.
[0026] Figure 3 for Figure 2 Mid-top view of the structure;
[0027] Figure 4 A three-dimensional structural diagram of a cover plate of an explosion-proof battery housing according to an embodiment of the present invention;
[0028] Figure 5 A three-dimensional structural diagram of an explosion-proof valve in one embodiment of an explosion-proof battery housing provided by this utility model;
[0029] Figure 6 This is a cross-sectional structural schematic diagram of an embodiment of an explosion-proof battery housing provided by this utility model;
[0030] Figure 7 This is a schematic diagram of the structure of an explosion-proof battery housing provided by this utility model after the explosion-proof partition is opened in one embodiment.
[0031] Explanation of icon numbers:
[0032] 100. Main body of the casing; 110. Divider plate; 111. Positive terminal; 112. Negative terminal; 120. Battery compartment; 130. Isolation compartment; 140. Pressure relief hole; 150. Isolation rib; 160. First snap-fit block;
[0033] 200. Explosion-proof valve; 210. Connecting frame; 220. Explosion-proof partition; 221. First groove; 222. Second groove;
[0034] 300, cover plate; 301, first terminal; 302, second terminal; 310, positive temperature coefficient thermistor; 320, spring contact; 330, second snap-fit block.
[0035] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.
[0037] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.
[0038] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.
[0039] Please see Figures 1 to 7This utility model discloses a lithium battery, which includes an explosion-proof battery casing. The explosion-proof battery casing can improve the problem that current lithium batteries, under abnormal operating conditions such as overcharging, short circuits, or thermal shock, generate a large amount of gas through electrolyte decomposition, leading to a sudden increase in pressure.
[0040] Specifically, the explosion-proof battery housing includes a housing body 100, an explosion-proof valve 200, and a cover plate 300.
[0041] like Figure 1 , 2 As shown, a partition plate 110 is fixedly connected inside the shell body 100. One side of the partition plate 110 is the battery compartment 120, and the other side is the isolation compartment 130. The shell body 100 is provided with a pressure relief hole 140 that connects to the outside and the isolation compartment 130.
[0042] Furthermore, the shell body 100 is made of 6061-T6 aluminum alloy by extrusion molding, with a wall thickness of 2.5mm and an anodized surface treatment. The partition plate 110 is 3mm thick and is laser-welded to the center line of the shell body 100. Through the partition plate 110, the cavity is divided into a battery compartment 120 with a volume ratio of 85% and an isolation compartment 130 with a volume ratio of 15%. However, this is not the only option, and can be determined according to actual needs.
[0043] The pressure relief holes 140 have a diameter of 8 mm and are symmetrically located on both sides of the isolation chamber 130. A porous ceramic filter element with a pore size of 50 μm can be embedded within the pressure relief hole 140. This porous ceramic filter element can be used to prevent electrolyte splashing.
[0044] Multiple insulating ribs 150, perpendicular to the bottom plate of the shell body 100, are fixedly connected to the inner wall of the shell body 100 and located within the battery compartment 120. For example... Figure 6 As shown, the isolation ribs 150 are one-third the height of the battery compartment 120, 2mm wide, and distributed in an equidistant checkerboard pattern. They are integrally molded with the main body 100. By setting the isolation ribs 150, a certain gap is maintained between the lithium battery pack and the inner wall of the main body 100. When an abnormality occurs in the battery pack, airflow is allowed to pass through this gap to the area of the explosion-proof valve 200.
[0045] The explosion-proof valve 200 is connected to the partition plate 110, and the explosion-proof valve 200 includes a connecting frame 210 and an explosion-proof partition plate 220.
[0046] Specifically, refer to Figure 6 , 7The connecting frame 210 is fixedly connected to the partition plate 110. The explosion-proof partition plate 220 is fixedly connected to the connecting frame 210, and the connecting frame 210 may be made of nickel-based alloy. It is fixed to both sides of the center line of the partition plate 110 by laser welding, with two sets arranged symmetrically. The explosion-proof partition plate 220 is made of 1.2mm thick 316L stainless steel plate.
[0047] The explosion-proof partition 220 is fixedly connected to the connecting frame 210, and at least a portion of the explosion-proof partition 220 can be disconnected and flipped when under pressure.
[0048] When the pressure value inside the battery compartment 120 exceeds a preset pressure value, at least a portion of the explosion-proof partition 220 can be disconnected and rotated toward the isolation compartment 130, so that the isolation compartment 130 is connected to the battery compartment 120.
[0049] In this way, the gas first enters the isolation chamber 130 from the battery compartment 120, thus providing a buffer space for the gas, and finally flows out from the pressure relief hole 140. The explosion-proof battery casing in this application can reduce the risk of deflagration by releasing pressure in stages, that is, the explosion-proof partition first opens the isolation chamber for buffering, and then releases the gas in a directional manner through the pressure relief hole.
[0050] Preferably, the surface where the pressure relief hole 140 is located is to the side of the surface where the explosion-proof partition 220 is located, so that after the gas is released from the explosion-proof partition 220, the gas will not directly rush to the pressure relief hole 140, but will be fully buffered in the isolation chamber before being released from the pressure relief hole, so as to further prevent explosion.
[0051] As a preferred option, such as Figure 5 As shown, the explosion-proof partition 220 has a first groove 221 and a second groove 222 on the side near the isolation chamber 130. The first groove 221 is elongated and perpendicular to one side wall of the shell body 100. The second groove 222 is formed along the connection line between the explosion-proof partition 220 and the connecting frame 210, and the depth of the second groove 222 is greater than that of the first groove 221. The explosion-proof partition 220 and the connecting frame 210 can break at the second groove 222, so that the area enclosed by the second groove 222 and the first groove 221 can rotate along the first groove 221 towards the isolation chamber 130.
[0052] The design of the second groove 222 can take advantage of the strength difference between the explosion-proof partition 220 and the connecting frame 210, so that the explosion-proof partition 220 can break quickly along the second groove 222 when facing large internal pressure, and quickly start to release pressure. At the same time, this design prevents the broken area of the explosion-proof partition 220 from flying around, further reducing the possibility of damage to other components.
[0053] For example, in one embodiment, during the processing of the explosion-proof partition 220, the first groove 221 is precision milled to a depth of 0.4 mm and a length of 30 mm, with its direction perpendicular to the long side of the housing. The second groove 222 has a depth of 0.6 mm and is machined along the welding line between the explosion-proof partition 220 and the connecting frame 210, with a 0.2 mm unpenetrated allowance left at the bottom of the groove.
[0054] Understandably, based on the above settings and after pressure testing and calibration, specifically, when the pressure in the battery compartment 120 reaches 2.2 MPa, the second groove 222 breaks, and the explosion-proof partition 220 rotates 85° around the first groove 221 toward the isolation compartment 130, with an opening area of 90%.
[0055] In some embodiments, the cover plate 300 is attached to the shell body 100 and is used to seal the isolation chamber 130.
[0056] Furthermore, in order to improve the effectiveness of this device in actual use, such as... Figure 2 As shown, a positive terminal 111 and a negative terminal 112 are connected to the separator plate 110, as follows: Figure 3 As shown, a first terminal 301 and a second terminal 302 are connected to the cover plate 300. The first terminal 301 is electrically connected to the positive terminal 111, and the second terminal 302 is electrically connected to the negative terminal 112.
[0057] Meanwhile, positive temperature coefficient thermistors 310 are connected between the first terminal 301 and the positive terminal 111, and between the second terminal 302 and the negative terminal 112, respectively. The positive temperature coefficient thermistor 310 is epoxy-encapsulated, with a room temperature resistance of 8mΩ, and its resistance rises to 1.2kΩ at a trigger temperature of 85℃. When the resistance increases, it effectively cuts off the circuit.
[0058] It should be noted that the first terminal 301 and the second terminal 302 are slidably connected to the cover plate 300, and spring pieces 320 are fixedly connected to the ends of the first terminal 301 and the second terminal 302 located in the isolation chamber 130. The spring pieces 320 are fixedly connected to the cover plate 300.
[0059] For example, the first terminal 301 and the second terminal 302 may be made of silver-plated copper with an I-shaped cross-section, and are slidably connected to the cover plate 300 via a Teflon guide rail. The spring 320 is made of beryllium bronze with a pre-compression of 1.5 mm and an initial contact pressure of 7 N.
[0060] In actual explosion-proof operation, when the pressure in the isolation chamber 130 exceeds the preset pressure value, the cover plate 300 moves outward by a certain distance, and the spring 320 resets so that the terminals do not contact each other, and the contact force between the terminals drops to 0N, so that the circuit is quickly disconnected. Specifically, the disconnection time of the circuit is less than or equal to 8ms. This design can further improve the explosion-proof effect of the device.
[0061] It should be noted that, in order to improve the connection between the cover plate 300 and the shell body 100, a snap-fit mechanism may be provided between the shell body 100 and the cover plate 300.
[0062] Specifically, such as Figure 3 , Figure 4 and Figure 7 As shown, the locking mechanism includes a first locking block 160 and a second locking block 330. The first locking block 160 is fixedly connected to the inner wall of the shell body 100, and the second locking block 330 is fixedly connected to the cover plate 300, and the first locking block 160 and the second locking block 330 are locked together. For example, the first locking block 160 is a trapezoidal protrusion on the side wall of the shell with a height of 2mm; the second locking block 330 is a dovetail groove on the inner side of the cover plate 300 with a depth of 1.8mm.
[0063] It should be noted that when the first latching block 160 and the second latching block 330 are engaged with each other, the spring piece 320 is in a compressed state. The engagement between the first latching block 160 and the second latching block 330 can effectively improve the connection between the cover plate 300 and the shell body 100.
[0064] During assembly, a hydraulic clamp can be used to apply 50N of pressure to fully engage the first locking block 160 and the second locking block 330, at which point the spring 320 is compressed to its designed preload. Therefore, the design of the spring 320 and the sliding terminal ensures the reliability of the electrical connection.
[0065] This utility model also provides a lithium battery, which includes at least the explosion-proof battery casing and the battery pack provided in any of the above embodiments.
[0066] Understandably, the battery pack is located within the battery compartment 120. The explosion-proof performance of the lithium battery disclosed herein is ensured by an explosion-proof battery housing.
[0067] Based on this, when the pressure inside the battery compartment 120 exceeds the preset pressure value, the explosion-proof partition 220 and the connecting frame 210 break at the second groove 222 and rotate along the first groove 221 towards the isolation chamber 130, thereby connecting the isolation chamber 130 with the battery compartment 120. At this time, the high-pressure gas and heat inside the battery compartment 120 can be released to the outside through the isolation chamber 130 and the pressure relief hole 140, preventing the pressure inside the battery compartment 120 from continuously rising and causing an explosion. At the same time, the positive temperature coefficient thermistor 310 can adjust the circuit resistance according to temperature changes, playing an overheat protection role. When the first latching block 160 and the second latching block 330 are latched together, the spring 320 is in a compressed state, ensuring a good electrical connection between the first terminal 301 and the second terminal 302 and the positive terminal 111 and the negative terminal 112.
[0068] In summary, this utility model discloses an explosion-proof battery casing and a lithium battery. It reduces the risk of deflagration through staged pressure relief: the explosion-proof partition 220 first opens the isolation chamber 130 for buffering, and then the pressure is released directionally through the pressure relief hole 140. This application also achieves electrical self-isolation, with pressure triggering a mechanical circuit disconnection, combined with PTC dual protection, resulting in a response time of less than 10ms. Furthermore, it possesses structural reusability; after pressure relief, simply replacing the explosion-proof valve 200 restores the battery's usability, reducing maintenance costs.
[0069] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.
Claims
1. An explosion-proof battery casing, characterized in that, include: The shell body (100) has a partition plate (110) fixedly connected inside it. One side of the partition plate (110) is a battery compartment (120) and the other side is an isolation compartment (130). The shell body (100) is provided with a pressure relief hole (140) that connects to the outside and the isolation compartment (130). An explosion-proof valve (200) is connected to the partition plate (110). The explosion-proof valve (200) includes a connecting frame (210) and an explosion-proof partition plate (220). The connecting frame (210) is fixedly connected to the partition plate (110). The explosion-proof partition plate (220) is fixedly connected to the connecting frame (210). At least a portion of the explosion-proof partition plate (220) can be disconnected and flipped under pressure. A cover plate (300) is attached to the shell body (100) for sealing the isolation chamber (130); If the pressure value inside the battery compartment (120) exceeds a preset pressure value, at least a portion of the explosion-proof partition (220) can be disconnected and rotated toward the isolation compartment (130) so that the isolation compartment (130) is connected to the battery compartment (120).
2. The explosion-proof battery casing according to claim 1, characterized in that, The pressure relief hole (140) is located to the side of the explosion-proof partition (220).
3. The explosion-proof battery casing according to claim 1, characterized in that, The explosion-proof partition (220) has a first groove (221) and a second groove (222) on the side near the isolation chamber (130). The first groove (221) is elongated and perpendicular to one side wall of the shell body (100). The second groove (222) is formed along the connection line between the explosion-proof partition (220) and the connecting frame (210), and the depth of the second groove (222) is greater than that of the first groove (221). The explosion-proof partition (220) and the connecting frame (210) can break at the second groove (222) so that the area enclosed by the second groove (222) and the first groove (221) can rotate along the first groove (221) toward the isolation chamber (130).
4. The explosion-proof battery casing according to claim 3, characterized in that, Two explosion-proof valves (200) are provided, and the two explosion-proof valves (200) are symmetrically arranged on the partition plate (110).
5. The explosion-proof battery casing according to claim 1, characterized in that, On the inner wall of the shell body (100) located inside the battery compartment (120), a plurality of isolation ribs (150) perpendicular to the bottom plate of the shell body (100) are fixedly connected.
6. The explosion-proof battery casing according to claim 1, characterized in that, The partition plate (110) is connected to a positive terminal (111) and a negative terminal (112), and the cover plate (300) is connected to a first terminal (301) and a second terminal (302); The first terminal (301) is electrically connected to the positive terminal (111), and the second terminal (302) is electrically connected to the negative terminal (112).
7. The explosion-proof battery casing according to claim 6, characterized in that, It also includes a positive temperature coefficient thermistor (310) located between the first terminal (301) and the positive terminal (111), and between the second terminal (302) and the negative terminal (112).
8. The explosion-proof battery casing according to claim 6, characterized in that, The first terminal (301) and the second terminal (302) are slidably connected to the cover plate (300), and a spring piece (320) is fixedly connected to the end of the first terminal (301) and the second terminal (302) located in the isolation chamber (130). The spring piece (320) is fixedly connected to the cover plate (300).
9. The explosion-proof battery casing according to claim 8, characterized in that, A first snap-fit block (160) is fixedly connected to the inner wall of the shell body (100), and a second snap-fit block (330) is fixedly connected to the cover plate (300), and the first snap-fit block (160) and the second snap-fit block (330) are snap-fitted together. When the first latching block (160) and the second latching block (330) are latched together, the spring piece (320) is in a compressed state.
10. A lithium battery, characterized in that, include: The explosion-proof battery housing according to any one of claims 1 to 9 above; And battery pack; The battery pack is located inside the battery compartment (120).