Battery case and battery

Abstract

The utility model discloses a battery case and battery, the battery case includes: frame, and the accommodation cavity is enclosed to form, the cover board, the cover is established on the frame and closes the accommodation cavity, wherein, the frame is provided with first explosion -proof valve, and the first explosion -proof valve includes first explosion -proof area and explosion -proof score, the thickness at first explosion -proof area is less than the wall thickness of frame, and the explosion -proof score sets up in first explosion -proof area. The utility model discloses battery case is applied to battery, and its explosion -proof valve structure will not accidentally split when battery carries out anti -drop test or suffers external impact in actual use, and when the pressure of battery inside is caused by overcharge, short circuit or other abnormal conditions and leads to sharp rise, can also split in time and smoothly, forms the stable and reliable pressure -relief passage, guarantees the effective realization of pressure -relief function.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, and in particular to a battery casing and a battery. Background Technology

[0002] With the booming development of new energy technologies, lithium batteries are widely used in consumer electronics and other fields due to their outstanding advantages such as high energy density, long cycle life and low self-discharge rate.

[0003] In related technologies, lithium batteries typically employ a combined structure of a steel casing and battery cells, with the battery cells encapsulated within the steel casing. The steel casing is constructed by welding a frame and a cover plate together. The cover plate is equipped with an explosion-proof valve, which includes explosion-proof grooves etched into it. These explosion-proof grooves are a crucial structural feature ensuring the safe operation of lithium batteries. When a lithium battery encounters abnormal conditions such as overcharging, short circuits, or thermal runaway during use, a large amount of gas rapidly accumulates inside the battery, causing a sharp increase in pressure. At this point, the explosion-proof grooves can crack, forming an effective pressure relief channel to quickly release the internal pressure, thereby preventing explosions caused by continuous pressure accumulation and constructing a critical line of defense for the safe operation of lithium batteries.

[0004] However, since the cover plate is typically only about 0.1mm thick, it is thinner and weaker than the frame. When lithium batteries undergo drop tests or are subjected to external impacts during actual use, the thin cover plate is easily deformed. Once the cover plate deforms, the explosion-proof markings on it will be squeezed, causing them to crack unexpectedly and affecting the normal use of the battery. If the explosion-proof markings are placed on the frame, although the higher strength of the frame can prevent deformation from squeezing the markings, the thicker structure of the frame will make it difficult for the markings to crack normally when the internal pressure of the battery rises abnormally, thus failing to achieve the expected pressure relief function. Utility Model Content

[0005] The main purpose of this utility model is to propose a battery casing that solves the technical problem that the thin steel casing of lithium batteries is prone to accidental cracking of the explosion-proof markings, while the thicker frame makes it difficult for the explosion-proof markings to crack normally.

[0006] To achieve the above objectives, this utility model proposes a battery casing, which includes:

[0007] The frame encloses and forms a receiving cavity;

[0008] A cover plate is placed on the frame and closes the receiving cavity;

[0009] The frame is provided with a first explosion-proof valve, which includes a first explosion-proof zone and explosion-proof markings. The thickness of the first explosion-proof zone is less than the wall thickness of the frame, and the explosion-proof markings are provided in the first explosion-proof zone.

[0010] Optionally, the frame includes multiple side frames connected end to end to enclose and form the receiving cavity;

[0011] The first explosion-proof valve is provided on at least one of the plurality of side frames.

[0012] Optionally, the number of cover plates is set to two, and the two cover plates are respectively disposed on opposite sides of the frame and welded to each of the side frames.

[0013] Optionally, the maximum length of the first explosion-proof zone is L1, and the length of the side frame with the first explosion-proof valve is L2, satisfying: L2-L1≥2mm; and / or,

[0014] The maximum width of the first explosion-proof zone is W1, and the width of the side frame of the first explosion-proof valve is W2, satisfying: W2-W1≥0.2mm.

[0015] Optionally, the residual thickness of the frame wall at the explosion-proof notch is 10μm to 50μm.

[0016] Optionally, the projection shape of the explosion-proof groove in the wall thickness direction of the frame is one of the following: linear, circular, elliptical, and polygonal.

[0017] Optionally, the wall thickness of the frame is greater than the thickness of the cover plate.

[0018] Optionally, the first explosion-proof valve is replaced by a second explosion-proof valve, which includes a second explosion-proof zone and a filling part with a variable heat-sensitive shape. A through-hole is formed in the second explosion-proof zone, extending through the frame along the wall thickness direction, and the filling part fills the through-hole.

[0019] Optionally, the filling portion is a heat-fusible filling portion; or,

[0020] The filling part is a heat-shrinkable filling part.

[0021] This utility model also proposes a battery, which includes a battery cell and a battery casing as described above, wherein the battery cell is housed in the accommodating cavity of the battery casing.

[0022] This utility model battery casing incorporates a first explosion-proof valve on the frame and explosion-proof markings in a first explosion-proof zone with a thickness less than the frame wall thickness. On one hand, by utilizing the frame's inherent high strength, the risk of accidental cracking of the explosion-proof markings due to deformation during drop tests or actual use is significantly reduced, ensuring normal battery use and improving the battery's impact resistance. On the other hand, the thinner design of the first explosion-proof zone allows the explosion-proof markings to crack promptly and smoothly when the internal pressure of the battery rises sharply due to abnormal conditions such as overcharging or short circuits, forming a stable and reliable pressure relief channel and ensuring the effective realization of the pressure relief function. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the battery casing in one embodiment of the present invention;

[0024] Figure 2 for Figure 1 A schematic diagram of a portion of the battery casing frame in the embodiment;

[0025] Figure 3 for Figure 1 A schematic diagram of the battery casing frame from one perspective in the embodiment;

[0026] Figure 4 This is a schematic diagram of the battery casing frame from one perspective in another embodiment of the present invention;

[0027] Figure 5 for Figure 4 A schematic diagram of a portion of the battery casing frame in the embodiment;

[0028] Figure 6 This is a schematic diagram of the battery casing in another embodiment of the present invention;

[0029] Figure 7 for Figure 6 A schematic diagram of the battery casing frame from one perspective in the embodiment; Attached image description:

[0031] label name label name 110 frame 120 cover plate 130 First explosion-proof valve 131 First explosion-proof zone 132 Explosion-proof markings 111 Side border 1111 First side frame 1112 Second side frame 140 Second explosion-proof valve 141 Second explosion-proof zone 142 Filling part

[0032] 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

[0033] The solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0034] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0035] It should also be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0036] Furthermore, the use of terms such as "first" and "second" in this utility model is 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. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0037] This utility model embodiment provides a battery casing, referring to... Figure 1 and Figure 2 The battery casing includes:

[0038] The frame 110 encloses and forms a receiving cavity;

[0039] A cover plate 120 is placed on the frame 110 and closes the receiving cavity;

[0040] The frame 110 is provided with a first explosion-proof valve 130, which includes a first explosion-proof area 131 and an explosion-proof groove 132. The thickness of the first explosion-proof area 131 is less than the wall thickness of the frame 110, and the explosion-proof groove 132 is provided in the first explosion-proof area 131.

[0041] like Figure 1As shown, the battery casing involved in this embodiment mainly consists of a frame 110 and a cover plate 120. The frame 110 encloses a cavity to accommodate the battery cells and other core components. The shape of the frame 110 can be set according to actual needs; for example, the frame 110 can be a rectangular frame. The cover plate 120 covers the frame 110 and seals the cavity, forming a complete battery casing structure together with the frame 110, providing protection and sealing for the internal battery cells. In actual manufacturing, the frame 110 can be made of a high-strength metal material, such as stainless steel, and processed into a cavity structure with a specific shape and size through stamping, forming, and other processes to ensure sufficient strength and rigidity to withstand external impacts and internal pressure. The cover plate 120 is also made of a suitable metal material and is tightly connected to the frame 110 through welding, riveting, or other methods to ensure the sealing of the cavity.

[0042] like Figure 1 and Figure 2 As shown, the first explosion-proof valve 130 is disposed on the frame 110, mainly including a first explosion-proof area 131 and explosion-proof grooves 132. The first explosion-proof area 131 can be formed by thinning the outer surface of the frame 110 through machining or laser processing, and its thickness is thinner than the wall thickness of the frame 110. Alternatively, it can be considered that the first explosion-proof area 131 is recessed from the outer surface of the frame 110 to form an explosion-proof cavity. The shape and size of the first explosion-proof area 131 can be set according to actual needs, for example, as... Figure 1 As shown, the first explosion-proof area 131 is elliptical in shape, but it can also be rectangular, including but not limited to this. Based on this, explosion-proof markings 132 are provided in the first explosion-proof area 131 to form a complete first explosion-proof valve 130 structure. Corresponding to the explosion-proof cavity in the first explosion-proof area 131, the explosion-proof markings 132 are located on the cavity wall of the explosion-proof cavity.

[0043] Specifically, during normal use of the battery, the frame 110, with its high strength and rigidity, and the sealed structure formed by its tight fit with the cover plate 120, provides a stable and reliable protective space for the battery cell, resisting possible external impacts such as collisions and compressions.

[0044] If the battery experiences overcharging, short circuit, or thermal runaway, a large amount of gas will rapidly be generated inside, causing a sharp increase in pressure within the containment cavity. At this point, because the thickness of the first explosion-proof zone 131 is less than the wall thickness of the frame 110, it becomes a weak point in the overall frame 110 structure. When the internal pressure reaches a certain threshold, the explosion-proof groove 132 located in the first explosion-proof zone 131 will crack promptly and smoothly under stress, thus forming an effective pressure relief channel. High-pressure gas is quickly discharged through this channel, rapidly reducing the internal pressure of the battery and preventing serious safety accidents such as explosions caused by continuous pressure accumulation, ensuring the safe operation of the battery.

[0045] In this embodiment, the battery casing has a first explosion-proof valve 130 on the frame 110 and an explosion-proof groove 132 is set in the first explosion-proof area 131 with a thickness less than the wall thickness of the frame 110. On the one hand, by utilizing the high strength of the frame 110 itself, the risk of the explosion-proof groove 132 accidentally cracking due to deformation under force can be significantly reduced when the battery is subjected to drop test or external force impact in actual use, thus ensuring the normal use of the battery and improving the battery's impact resistance. On the other hand, the thin design of the first explosion-proof area 131 allows the explosion-proof groove 132 to crack in a timely and smooth manner when the pressure inside the battery rises sharply due to abnormal conditions such as overcharging or short circuit, forming a stable and reliable pressure relief channel and ensuring the effective realization of the pressure relief function.

[0046] Furthermore, this design does not require significant modifications to existing battery manufacturing processes, facilitating mass production applications. This ensures battery safety under normal use and unexpected conditions, while also improving overall battery reliability and lifespan, broadening the battery's application range in more demanding scenarios, and demonstrating significant technological advantages and practical value.

[0047] In some embodiments, such as Figure 1 and Figure 2 As shown, the frame 110 includes multiple side frames 111, which are connected end to end to enclose and form an accommodating cavity.

[0048] At least one of the multiple side frames 111 is provided with a first explosion-proof valve 130.

[0049] In this embodiment, the frame 110 is composed of multiple side frames 111, which are connected end-to-end to form a cavity for accommodating battery cells. The number of side frames 111 can be set according to actual needs; for example, there can be four side frames 111, but this is not limited to them. The side frames 111 can be integrally formed or fixed by high-strength connection processes such as welding and riveting to ensure the sealing and structural stability of the cavity and provide reliable protective space for the internal battery cells. A first explosion-proof valve 130 is provided on at least one of the multiple side frames 111.

[0050] In practical applications, depending on the battery size, usage scenario, and internal pressure distribution characteristics, a first explosion-proof valve 130 can be installed on one or more side frames 111 of the frame 110 to achieve optimal pressure relief and safety protection. For example, multiple first explosion-proof valves 130 can be installed on multiple side frames 111 to form a multi-point pressure relief mechanism, preventing pressure concentration in one place and avoiding irreversible damage to the battery casing due to excessive local pressure, thereby improving the overall pressure resistance and service life of the battery casing.

[0051] Reference Figure 1 The multiple side borders 111 include two first side borders 1111 and two second side borders 1112, the length of the second side border 1112 is less than the length of the first side border 1111;

[0052] In the width direction of the frame 110, two first side borders 1111 are arranged opposite each other; in the length direction of the frame 110, two second side borders 1112 are arranged opposite each other.

[0053] A first explosion-proof valve 130 is provided on one of the two first side frames 1111. Alternatively, a first explosion-proof valve 130 is provided on both first side frames 1111.

[0054] In this embodiment, the frame 110 adopts a rectangular structure design, consisting of multiple side frames 111, specifically including two first side frames 1111 and two second side frames 1112, wherein the length of the second side frames 1112 is less than the length of the first side frames 1111. In the width direction of the frame 110, the two first side frames 1111 are arranged opposite each other, providing the main longitudinal boundary of the frame 110; in the length direction of the frame 110, the two second side frames 1112 are arranged opposite each other, forming the lateral boundary of the frame 110. The four side frames 111 are connected end-to-end through high-strength processes such as welding and riveting, precisely enclosing a cavity for accommodating the battery cells.

[0055] Since the first side frame 1111 is relatively long and has a large surface area in the frame 110 structure, setting the first explosion-proof valve 130 at this position will not weaken the structural strength of the frame 110 too much. In other words, the structural characteristics of the side frame 111 are fully utilized to optimize the safety protection performance of the battery case, so that the battery case can still maintain good integrity when subjected to external forces such as drops and collisions.

[0056] In some embodiments, two cover plates 120 are provided, each disposed on opposite sides of the frame 110 and welded to the respective side frames 111. In this embodiment, the battery adopts a double-cover plate 120 structure design. Specifically, in the thickness direction of the frame 110 (different from the wall thickness direction of the frame 110), or in the width direction of the side frames 111, the frame 110 serves as a middle frame, and the two cover plates 120 are respectively installed on opposite sides of the frame 110 and tightly connected to the respective side frames 111 of the frame 110 through a welding process. The welding process employs high-precision laser welding or ultrasonic welding technology to ensure that a continuous, uniform, and high-strength weld is formed between the cover plate 120 and the side frames 111, so that the cover plate 120 and the frame 110 together constitute a complete and sealed accommodating space for safely and stably encapsulating the battery cell and other internal components.

[0057] In addition to the above embodiments, in other embodiments, the number of cover plates 120 is set to one, and the cover plate 120 is disposed on one side of the frame 110 and welded to each side frame 111. That is, the battery adopts a single cover plate 120 structure design, the frame 110 also includes a bottom frame, multiple side frames 111 are disposed along the edge of the bottom frame and integrally formed with the bottom frame, and the cover plate 120 is positioned opposite to the bottom frame to cover the frame 110.

[0058] In some embodiments, refer to Figure 3 The maximum length of the first explosion-proof zone 131 is L1, and the length of the side frame 111 with the first explosion-proof valve 130 is L2, satisfying: L2-L1≥2mm; and / or,

[0059] The maximum width of the first explosion-proof zone 131 is W1, and the width of the side frame 111 of the first explosion-proof valve 130 is W2, satisfying: W2-W1≥0.2mm.

[0060] In this embodiment, the dimensions of the area where the first explosion-proof valve 130 is located are precisely defined. Specifically, for the side frame 111 of the frame 110 where the first explosion-proof valve 130 is installed, the dimensional relationship between the first explosion-proof area 131 and the side frame 111 in the length and / or width directions is clearly defined.

[0061] In the length direction, let the maximum length of the first explosion-proof zone 131 be L1, and the length of the side frame 111 with the first explosion-proof valve 130 be L2. Both must satisfy L2-L1≥2mm. This dimensional requirement is based on the stress characteristics of the battery during actual use and testing. When the battery undergoes drop testing or is subjected to external impact during use, the corners of the frame 110 are prone to deformation. If L2-L1<2mm, the position of the first explosion-proof valve 130 is too close to the corner of the frame 110, and it will be affected by the stress transmission caused by the deformation of the corner of the frame 110. This could lead to accidental cracking of the explosion-proof notch 132 or related structures in the first explosion-proof valve 130, thereby compromising the explosion-proof function and overall safety of the battery casing. By limiting L2-L1≥2mm, the problem of the first explosion-proof valve 130 accidentally cracking due to the deformation of the corner of the frame 110 during cell drop testing or actual use is effectively avoided. Alternatively, the minimum distance between the edges of the first explosion-proof zone 131 and the side frame 111 on either side along the length direction shall not be less than 1mm, and may be set within the range of 1mm to 21mm.

[0062] In the width direction, let the maximum width of the first explosion-proof zone 131 be W1, and the width of the side frame 111 with the first explosion-proof valve 130 be W2. Both must satisfy W2 - W1 ≥ 0.2 mm. This dimensional limitation is closely related to the welding process of the frame 110 and the cover plate 120. During the battery casing manufacturing process, the frame 110 and the cover plate 120 are connected by welding. If W2 - W1 < 0.2 mm, it means that the first explosion-proof zone 131 is too close to the edge of the side frame 111 in the width direction, resulting in insufficient effective weld penetration when welding the frame 110 and the cover plate 120. Insufficient weld penetration will directly affect the welding tensile strength between the cover plate 120 and the frame 110, reducing the strength of the welded connection, thereby increasing the risk of cell leakage and threatening the normal use and safety of the battery. By precisely limiting the dimensions of the first explosion-proof zone 131 and the side frame 111 in the length and width directions as described above, the reliability of the first explosion-proof valve 130 under various operating conditions and the stability of the overall battery casing structure are ensured. By limiting W2-W1 to ≥ 0.2mm, sufficient effective weld penetration is ensured when welding the frame 110 and the cover plate 120. Sufficient penetration guarantees a strong welded connection between the cover plate 120 and the frame 110, increases weld tensile strength, and effectively reduces the risk of cell leakage. Alternatively, the minimum distance between the edges of the first explosion-proof zone 131 and the side frame 111 on either side in the width direction is not less than 0.1mm, specifically within the range of 0.1mm to 2.1mm.

[0063] In some embodiments, the residual wall thickness of the frame 110 at the explosion-proof notch 132 is 10 μm to 50 μm. Wherein, as... Figure 2 As shown, the residual thickness of the frame 110 at the explosion-proof notch 132 is t. In actual settings, t can be selected within the range of 10μm to 50μm. For example, t can be set to 10μm, 30μm, or 50μm. From a safety perspective, if the residual thickness t is too small, i.e., the explosion-proof notch 132 is too deep, it may cause the explosion-proof notch 132 to crack unexpectedly when the battery is subjected to only slight vibration or small external force during normal use, affecting the normal use of the battery. On the other hand, if the residual thickness t is too large, it means that the explosion-proof notch 132 is too shallow. When the internal pressure of the battery rises sharply due to abnormal conditions, the explosion-proof notch 132 may not be able to crack in time under the appropriate pressure threshold, failing to effectively release pressure and increasing the risk of explosion. In this embodiment, by controlling the residual thickness t to be between 10μm and 50μm, the explosion-proof groove 132 can maintain structural stability during normal battery operation and can quickly and reliably open the pressure relief channel when the internal pressure reaches a dangerous value. This precisely balances the safety of normal use with the timeliness of abnormal pressure relief, greatly improving the safety performance of the battery.

[0064] In some embodiments, refer to Figures 3 to 5The explosion-proof notch 132, projected onto the wall thickness of the frame 110, can be linear, elliptical, or polygonal. Linear notches include straight lines and curves, while polygons include triangles, rectangles, trapezoids, parallelograms, and other geometric shapes. Specifically, when the explosion-proof notch 132 is projected as a line, whether it's the simplicity of a straight line or the flexibility of a curve, it can be rationally distributed in the first explosion-proof area 131 according to the structural characteristics of the battery casing and actual usage requirements. Specifically, straight explosion-proof notches 132 are relatively simple to manufacture and can quickly form a regular stress concentration line in the first explosion-proof area 131. When the internal pressure of the battery increases, it can quickly crack along the straight direction, forming a straight and smooth pressure relief channel, allowing gas to escape rapidly. Curved explosion-proof notches 132 can better adapt to the complex structural shape of the battery casing. In some irregular areas of the frame 110, curves can more rationally disperse and concentrate stress, ensuring stable cracking under various pressure distribution conditions and improving the reliability of pressure relief. like Figure 4 and Figure 5 As shown, if the projection is elliptical, due to its symmetrical curved structure, the stress will be evenly distributed around the elliptical contour under the pressure inside the battery, so that the explosion-proof groove 132 can be cracked more evenly under stress, and the area of ​​the pressure relief channel formed is more stable, effectively avoiding unexpected cracking caused by excessive local stress, and improving the controllability and stability of the pressure relief process; the explosion-proof groove 132 with polygonal projection, such as triangles, rectangles, etc., can accurately control the stress distribution path due to its regular geometric shape.

[0065] The diverse projection shape design of the explosion-proof grooves 132 in this embodiment allows the battery case to flexibly select the most suitable explosion-proof groove shape 132 according to different application scenarios, battery structures and usage requirements, which significantly improves the adaptability and versatility of the battery case.

[0066] In some embodiments, the wall thickness of the frame 110 is greater than the thickness of the cover plate 120. In this embodiment, because the wall thickness of the frame 110 is greater than the thickness of the cover plate 120, the first explosion-proof valve 130 disposed on the frame 110 has a more stable supporting foundation. When the battery is subjected to external impact, such as a drop or collision, or when internal abnormalities such as overcharging or short circuits cause pressure to rise, the thicker frame 110 can effectively resist deformation, reducing the risk of the first explosion-proof valve 130 being accidentally opened due to structural deformation (i.e., the explosion-proof notch 132 being accidentally cracked). The wall thickness of the frame 110 can be 0.1mm to 0.3mm, and the thickness of the cover plate 120 can be 0.05mm to 0.1mm.

[0067] To address the technical problem that the thin battery cover 120 is prone to accidental cracking of the explosion-proof groove 132, while the thick frame 110 makes it difficult for the explosion-proof groove 132 to crack normally, in addition to the structural design of the first explosion-proof valve 130 in the above embodiment, other explosion-proof valve structural designs can also be adopted as an optional solution, such as:

[0068] In some embodiments, refer to Figure 6 and Figure 7 The first explosion-proof valve 130 is replaced by the second explosion-proof valve 140. The second explosion-proof valve 140 includes a second explosion-proof zone 141 and a filling part 142 with a variable heat-induced shape. A through-hole is formed in the second explosion-proof zone 141, which extends through the frame 110 along the wall thickness direction. The filling part 142 fills the through-hole.

[0069] The second explosion-proof valve 140 is disposed on the frame 110 and consists of a second explosion-proof zone 141 and a filling part 142. The through-hole in the second explosion-proof zone 141 can be formed by conventional machining or laser processing, and the through-hole penetrates the frame 110 along its wall thickness direction. The filling part 142 can be made of a material with heat-sensitive properties, such as a low-melting-point alloy or heat-sensitive plastic, but is not limited to these. During battery assembly, the filling part 142 is precisely filled into the through-hole, ensuring a tight fit with the inner wall of the through-hole. It remains stable and solid at room temperature, sealing the through-hole. When the temperature rises to a preset temperature, the filling part 142 rapidly undergoes a morphological change, opening the through-hole. Optionally, the position and size of the second explosion-proof zone 141 can be set with reference to the position and size of the first explosion-proof zone 131 in the aforementioned embodiment; this embodiment will not elaborate on this.

[0070] Specifically, when the battery is working normally, the closed structure formed by the frame 110 and the cover plate 120 provides a safe and stable working environment for the battery cell. The filling part 142 of the second explosion-proof valve 140 remains solid, sealing the through-hole and ensuring the sealing and stability of the battery.

[0071] When a battery experiences abnormal conditions such as overcharging, short circuits, or thermal runaway, the electrochemical reactions inside the battery intensify, generating a large amount of heat and causing a rapid rise in the internal temperature. As the temperature increases, the filling portion 142 undergoes morphological changes due to heat. For example, the low-melting-point alloy filling portion 142 gradually melts, and the heat-sensitive plastic filling portion 142 softens or even vaporizes. This change in the shape of the filling portion 142 prevents it from continuing to fill the through-hole, opening it up. The high-pressure gas accumulated inside the battery is then rapidly released through the through-hole, forming a pressure relief channel. This reduces the internal pressure of the battery, preventing safety accidents such as explosions or fires caused by excessive pressure, and ensuring the safe operation of the battery.

[0072] This utility model's battery casing, by setting a second explosion-proof valve 140 on the frame 110, fills the through-hole formed at the second explosion-proof zone 141 with a heat-sensitive, shape-changing filling part 142. On the one hand, by utilizing the high strength of the frame 110 itself, the risk of accidental cracking of the explosion-proof valve (such as the filling part 142) due to deformation under force can be significantly reduced when the battery is subjected to drop tests or external impacts in actual use, ensuring normal battery use and improving the battery's impact resistance. On the other hand, the filling design of the heat-sensitive, shape-changing filling part 142, replacing the structural design of the explosion-proof notch 132, allows the through-hole to be opened smoothly by the heat-sensitive filling part 142 changing shape when the pressure inside the battery rises sharply due to abnormal conditions such as overcharging or short circuits. The high-pressure gas accumulated inside the battery is quickly discharged through the through-hole, forming a stable and reliable pressure relief channel, ensuring the effective realization of the pressure relief function.

[0073] In some embodiments, refer to Figure 6 and Figure 7 The filling part 142 is a heat-fusible filling part 142; or,

[0074] The filling part 142 is a heat-shrinkable filling part 142.

[0075] In this embodiment, the filling portion 142 of the second explosion-proof valve 140 has a variety of designs. Specifically, the filling portion 142 can be a heat-melting filling portion 142 or a heat-shrinkable filling portion 142.

[0076] When the filling part 142 is a heat-melting filling part 142, it is made of a material with a specific melting point, such as a low-melting-point alloy or a fusible plastic. Under normal operating temperature conditions, this type of filling part 142 remains solid and tightly fills the penetration opening of the second explosion-proof zone 141. Relying on its own mechanical strength and tight bonding with the inner wall of the penetration opening, it maintains the closed state of the penetration opening, ensuring the internal sealing of the battery, so that the frame 110 and the cover plate 120 together provide a stable working environment for the battery cell. However, when the temperature inside the battery rises sharply due to abnormal conditions such as overcharging, short circuit, or thermal runaway, reaching the melting point of the filling part 142, the filling part 142 melts rapidly. The liquid filling part 142 can no longer seal the penetration opening, and the penetration opening is opened, thereby forming a pressure relief channel to release the excessive pressure inside the battery in a timely manner.

[0077] When the filling part 142 is a heat-shrinkable filling part 142, a material with heat-shrinkable properties is selected, such as certain heat-shrinkable rubbers or shape memory polymers. Under normal operating conditions, the filling part 142 fills the through-hole, ensuring the airtightness of the battery interior. Once abnormal heating occurs inside the battery, as the temperature rises, the filling part 142 shrinks in volume due to its heat-shrinkable properties, creating a gap between it and the inner wall of the through-hole, thereby opening the through-hole and achieving rapid pressure relief, preventing the battery's internal pressure from continuously rising and causing a safety accident.

[0078] This utility model embodiment also proposes a battery, which includes a battery cell and a battery casing as described above, wherein the battery cell is housed in the accommodating cavity of the battery casing. The specific structure of the battery casing is the same as described in the above embodiments. Since this battery adopts all the technical solutions of all the above embodiments, it possesses at least all the technical effects brought about by the technical solutions of the above embodiments, and will not be elaborated further here. The battery can be a lithium battery.

[0079] The above description is only a part or preferred embodiment of this utility model. Neither the text nor the drawings should limit the scope of protection of this utility model. All equivalent structural transformations made using the content of this utility model specification and drawings under the overall concept of this utility model, or direct / indirect applications in other related technical fields, are included within the scope of protection of this utility model.

Claims

1. A battery casing, characterized in that, include: The frame encloses and forms a receiving cavity; A cover plate is placed on the frame and closes the receiving cavity; The frame is provided with a first explosion-proof valve, which includes a first explosion-proof zone and explosion-proof markings. The thickness of the first explosion-proof zone is less than the wall thickness of the frame, and the explosion-proof markings are provided in the first explosion-proof zone.

2. The battery casing according to claim 1, characterized in that, The frame includes multiple side frames, which are connected end to end to enclose and form the receiving cavity; The first explosion-proof valve is provided on at least one of the plurality of side frames.

3. The battery casing according to claim 2, characterized in that, The number of cover plates is set to two, and the two cover plates are respectively disposed on opposite sides of the frame and welded to each of the side frames.

4. The battery casing according to claim 2, characterized in that, The maximum length of the first explosion-proof zone is L1, and the length of the side frame containing the first explosion-proof valve is L2, satisfying: L2-L1≥2mm; and / or, The maximum width of the first explosion-proof zone is W1, and the width of the side frame of the first explosion-proof valve is W2, satisfying: W2-W1≥0.2mm.

5. The battery casing according to claim 1, characterized in that, The residual thickness of the frame wall at the explosion-proof markings is 10μm to 50μm.

6. The battery casing according to claim 1, characterized in that, The projection shape of the explosion-proof markings in the wall thickness direction of the frame is one of the following: linear, circular, elliptical, and polygonal.

7. The battery casing according to claim 1, characterized in that, The wall thickness of the frame is greater than the thickness of the cover plate.

8. The battery casing according to any one of claims 1 to 7, characterized in that, The first explosion-proof valve is replaced by a second explosion-proof valve, which includes a second explosion-proof zone and a filling part with a variable heat-sensitive shape. A through-hole is formed in the second explosion-proof zone, which extends through the frame along the wall thickness direction of the frame. The filling part fills the through-hole.

9. The battery casing according to claim 8, characterized in that, The filling part is a heat-melting filling part; or, The filling part is a heat-shrinkable filling part.

10. A battery, characterized in that, It includes a battery cell and a battery casing as described in any one of claims 1 to 9, wherein the battery cell is housed in the receiving cavity of the battery casing.

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