Battery case, battery cell, and battery device

Abstract

The utility model discloses a battery shell, battery monomer and battery device, battery shell includes: casing and insulating coating. The casing is equipped with pressure release mouth, is provided with pressure relief valve at pressure release mouth, and the pressure relief valve includes pressure relief valve piece and connecting ring, and the connecting ring is set around pressure relief valve piece and is connected between the outer peripheral wall of pressure relief valve piece and the inner peripheral wall of pressure release mouth, and the thickness of at least part of connecting ring is less than the thickness of casing and the thickness of pressure relief valve piece, and the insulating coating is set on the outer surface of casing, and the insulating coating does not cover connecting ring, to make connecting ring bare. According to the battery shell of the utility model, through insulating coating replaces blue film and makes the connecting place of insulating coating not cover pressure relief valve and casing, plays the insulating protection of battery at the same time, can make the burst pressure value of pressure relief valve accurate and reliable, is favorable to the safety of battery.

Description

Technical Field

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

[0002] In related technologies, the outer casing of batteries is typically made of metal. To prevent short circuits caused by contact between external conductive materials and the casing, an insulating layer is required to cover its outer surface. However, in these technologies, a blue film is used to cover the outer surface of the casing. During the application of this blue film, the coverage area cannot be precisely controlled. The film often covers the connection point between the pressure relief valve and the casing, leading to inaccurate pressure relief thresholds, abnormal rupture modes, and serious safety hazards. Therefore, improvements are needed. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, one objective of this invention is to provide a battery casing that uses an insulating coating instead of a blue film, and ensures that the insulating coating does not cover the connection between the pressure relief valve and the casing. This provides insulation protection for the battery while allowing the burst pressure value of the pressure relief valve to be accurate and reliable, thus improving battery safety.

[0004] This utility model also proposes a battery cell having the above-mentioned battery casing.

[0005] This utility model also proposes a battery device having the above-mentioned battery cells.

[0006] A battery casing according to a first aspect of the present invention includes: a housing having a pressure relief port, a pressure relief valve being provided at the pressure relief port, the pressure relief valve including a pressure relief valve plate and a connecting ring, the connecting ring being disposed around the pressure relief valve plate and connected between the outer peripheral wall of the pressure relief valve plate and the inner peripheral wall of the pressure relief port, at least a portion of the thickness of the connecting ring being less than the thickness of the housing and the thickness of the pressure relief valve plate; and an insulating coating disposed on the outer surface of the housing, the insulating coating not covering the connecting ring, thereby exposing the connecting ring.

[0007] According to the battery casing of this utility model embodiment, an insulating coating is provided on the outer surface of the casing to provide insulation protection. Since the insulating coating is applied to the outer surface of the casing, the coverage area of ​​the insulating coating can be precisely controlled, ensuring that the insulating coating does not cover the connecting ring between the outer peripheral wall of the pressure relief valve plate and the inner peripheral wall of the pressure relief port (i.e., the connection point between the pressure relief valve and the casing). Therefore, while providing insulation protection for the battery by providing an insulating coating on the outer surface of the casing, the burst pressure value of the pressure relief valve is accurate and reliable, which is beneficial to improving battery safety. Furthermore, by using an insulating coating instead of a blue film, the insulating coating is less likely to detach from the casing and has better scratch resistance. Its insulation protection performance is less prone to failure, providing stable and reliable insulation protection.

[0008] According to some embodiments of the present invention, the insulating coating covers the outer surface of the pressure relief valve plate; or, the insulating coating does not cover the pressure relief valve plate, leaving the pressure relief valve plate exposed.

[0009] According to some embodiments of the present invention, the connecting ring is provided with grooves; and / or the pressure relief valve is circular.

[0010] According to some embodiments of the present invention, the edge of the insulating coating near the connecting ring is the coating edge, and the distance between the coating edge and the connecting ring is D, where 0.5mm≤D≤5mm.

[0011] According to some embodiments of the present invention, the insulating coating includes a coating body area and a coating thinning area, the thickness of the coating thinning area is less than the thickness of the coating body area, the coating thinning area is provided on the inner circumferential side and / or the outer circumferential side of the connecting ring, and the coating thinning area is formed as an annulus extending circumferentially along the connecting ring.

[0012] According to some embodiments of the present invention, the thickness of the coating thinning region gradually decreases in the radial direction of the connecting ring and in the direction close to the connecting ring.

[0013] According to some embodiments of the present invention, the radial width of the coating thinning zone is d, and the thickness of the coating main zone is T, where 1mm≤d≤3mm or d≥5T.

[0014] According to some embodiments of this utility model, the thickness of the coating body area is T, where 50μm≤T≤300μm.

[0015] A battery cell according to a second aspect of the present invention includes: a battery casing according to the first aspect of the present invention; and an electrode assembly disposed within the battery casing.

[0016] According to the battery cell of this utility model embodiment, by setting the above-mentioned battery casing, the battery casing replaces the blue film with an insulating coating and the insulating coating does not cover the connection between the pressure relief valve and the casing, which not only provides insulation protection for the battery, but also makes the burst pressure value of the pressure relief valve accurate and reliable, which is beneficial to improving the safety of the battery.

[0017] A battery device according to a third aspect of the present invention includes: a housing; and a battery cell according to the second aspect of the present invention, wherein the battery cell is disposed within the housing.

[0018] According to the battery device of the present invention, by setting the above-mentioned battery cell, the battery casing of the battery cell is replaced by an insulating coating instead of a blue film, and the insulating coating does not cover the connection between the pressure relief valve and the casing. This provides insulation protection for the battery, while making the burst pressure value of the pressure relief valve accurate and reliable, which is beneficial to improving the safety of the battery.

[0019] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of a battery cell according to some embodiments of the present invention; Figure 2 It is along Figure 1 Cross-sectional view of line AA in the middle; Figure 3 yes Figure 2 Enlarged view of point B in the middle; Figure 4 This is a schematic diagram showing the coverage of the insulating coating at the location of the pressure relief valve plate on the battery casing according to some embodiments of the present utility model, wherein the insulating coating does not cover the connecting ring; Figure 5 This is a schematic diagram showing the coverage of the insulating coating at the location of the pressure relief valve plate on the battery casing according to other embodiments of the present invention, wherein the insulating coating does not cover the connecting ring and the pressure relief valve plate; Figure 6 This is a schematic diagram of a battery device according to some embodiments of the present invention.

[0021] Figure label: 100. Battery cell; 10. Battery casing; 11. Housing; 12. Insulating coating; 121. Main coating area; 122. Coating thinning area; 13. Pressure relief valve; 131. Pressure relief valve plate; 132. Connecting ring; 133. Score; 20. Electrode assembly; 200. Battery assembly; 30. Housing. Detailed Implementation

[0022] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0023] The following is for reference. Figures 1-5 The battery casing 10 according to an embodiment of the present utility model is described.

[0024] refer to Figures 1-3 According to a first aspect embodiment of the present invention, a battery casing 10 includes a casing 11 and an insulating coating 12. The casing 11 has a pressure relief port, and a pressure relief valve 13 is provided at the pressure relief port, covering the pressure relief port. The pressure relief valve 13 includes a pressure relief valve plate 13 and a connecting ring 132, the connecting ring 132 surrounding the pressure relief valve plate 13 and connecting between the outer peripheral wall of the pressure relief valve plate 13 and the inner peripheral wall of the pressure relief port.

[0025] The thickness of at least a portion of the connecting ring 132 is less than the thickness of the housing 11 and the thickness of the pressure relief valve plate 131. For example, the thickness of a portion of the connecting ring 132 is less than the thickness of the housing 11, and the thickness of a portion of the connecting ring 132 is less than the thickness of the pressure relief valve plate 131. For example, the thickness of the connecting ring 132 at each location is less than the thickness of the housing 11, and the thickness of a portion of the connecting ring 132 is less than the thickness of the pressure relief valve plate 131. For example, the thickness of a portion of the connecting ring 132 is less than the thickness of the housing 11, and the thickness of a portion of the connecting ring 132 is less than the thickness of the pressure relief valve plate 131. For example, the thickness of the connecting ring 132 at each location is less than the thickness of the housing 11, and the thickness of a portion of the connecting ring 132 is less than the thickness of the pressure relief valve plate 131.

[0026] Since at least a portion of the thickness of the connecting ring 132 is less than the thickness of the housing 11 and the pressure relief valve plate 131, the structural strength of the connecting ring 132 is relatively weaker than that of the housing 11 and the pressure relief valve plate 131. When the battery experiences thermal runaway, the battery housing 10 will rupture preferentially from the connecting ring 132, and the pressure relief valve 13 will open the pressure relief port, thereby allowing the high-temperature gas inside the battery housing 10 to be discharged from the pressure relief port, which can achieve directional pressure relief.

[0027] The housing 11 can be a metal housing 11, such as a steel housing, an aluminum housing, or an aluminum alloy housing.

[0028] An insulating coating 12 is applied to the outer surface of the housing 11. The insulating coating 12 can be applied to the outer surface of the housing 11 by spraying or coating. The insulating coating 12 can be a resin coating, such as an epoxy resin coating or a polyurethane resin coating. By covering the outer surface of the housing 11 with the insulating coating 12, the battery can be insulated and protected, preventing short circuits caused by contact between external conductive materials and the housing 11. By replacing the blue film with the insulating coating 12, the insulating coating 12 is less likely to peel off from the housing 11 and has better scratch resistance. Its insulating protective performance is less prone to failure, providing stable and reliable insulation protection.

[0029] In this design, the insulating coating 12 does not cover the connecting ring 132, leaving the connecting ring 132 exposed. Since the insulating coating 12 is applied to the outer surface of the housing 11, its coverage area can be precisely controlled. This ensures that the insulating coating 12 does not cover the connecting ring 132 between the pressure relief valve plate 13 and the inner circumferential wall of the pressure relief port (i.e., the connection point between the pressure relief valve 13 and the housing 11), leaving the connecting ring 132 exposed. This avoids affecting the thickness and mechanical properties of the connecting ring 132. Furthermore, if the insulating coating 12 covers the connecting ring 132, the insulating coating 12 at the location of the connecting ring 132 may age, become brittle, crack, or peel off during long-term use due to vibration and thermal cycling. This aging can unpredictably alter the burst performance of the pressure relief valve 13. By leaving the connecting ring 132 exposed, the performance uncertainty caused by the aging of the insulating coating 12 at the location of the connecting ring 132 can be better avoided.

[0030] An insulating coating 12 is provided on the outer surface of the housing 11 to provide insulation protection for the battery, while ensuring that the insulating coating 12 does not cover the connecting ring 132, so that the connecting ring 132 is exposed. This allows the burst pressure value of the pressure relief valve 13 to be accurate and reliable, which is beneficial to improving the safety of the battery.

[0031] According to the embodiment of this utility model, the battery casing 10, by providing an insulating coating 12 on the outer surface of the casing 11, can achieve an insulating and protective function. Since the insulating coating 12 is applied to cover the outer surface of the casing 11, the coverage area of ​​the insulating coating 12 can be precisely controlled, ensuring that the insulating coating 12 does not cover the connecting ring 132 between the outer peripheral wall of the pressure relief valve plate 13 and the inner peripheral wall of the pressure relief port (i.e., the connection position between the pressure relief valve 13 and the casing 11). Thus, while providing insulating protection for the battery by providing an insulating coating 12 on the outer surface of the casing 11, the burst pressure value of the pressure relief valve 13 can be made accurate and reliable, which is beneficial to improving battery safety. In addition, by replacing the blue film with the insulating coating 12, the insulating coating 12 is less likely to fall off the casing 11 and has better scratch resistance. The insulating protective performance is less likely to fail, and it can provide a stable and reliable insulating and protective function.

[0032] According to some embodiments of this utility model, refer to Figure 4 The insulating coating 12 does not cover the connecting ring 132, but covers the outer surface of the pressure relief valve plate 13. This exposes the connecting ring 132 between the pressure relief valve plate 13 and the inner peripheral wall of the pressure relief port, and ensures that the outer surface of the pressure relief valve plate is covered by the insulating coating 12, thereby achieving the following technical effects: First, it can enhance local protection and improve corrosion resistance: Covering the non-functional area of ​​the pressure relief valve 13 (the area of ​​the pressure relief valve 13 other than the connecting ring 132 or the notch 133, i.e. the pressure relief valve plate 13) with an insulating coating 12 can provide a physical barrier for the pressure relief valve plate 13, isolating it from external water vapor, salt spray, chemicals and other corrosive media. The insulating coating 12 itself has good chemical corrosion resistance. The insulating coating 12 covering the outer surface of the pressure relief valve plate 13 can effectively prevent pitting corrosion, oxidation and other damage to the outer surface of the pressure relief valve plate 13, which has a positive effect on extending the material life of the non-core area of ​​the pressure relief valve 13. Secondly, it can optimize the electric field distribution and reduce the risk of edge partial discharge: In high-voltage battery systems, there may be electric field concentration at the edge of the metal casing 11. If the central burst area of ​​the pressure relief valve 13 (i.e., the pressure relief valve plate 13) is close to surrounding components with high voltage potential, covering the outer surface of the pressure relief valve plate 13 with an insulating coating 12 can smooth the electric field distribution. The dielectric constant of the insulating coating 12 is different from that of air. After the outer surface of the pressure relief valve plate 13 is coated with an insulating coating 12, the uniformity of the electric field can be improved, which theoretically can reduce the potential risk of partial discharge at the metal edge.

[0033] Third, it can simplify the protection management in the production process: by covering the outer surface of the pressure relief valve plate 13 with an insulating coating 12, there is no need to provide special physical protection for the pressure relief valve plate 13 during battery production, transportation and assembly, because the insulating coating 12 itself provides a certain degree of resistance to minor scratches, avoiding the need to separately protect the outer surface of the pressure relief valve plate 13 during process turnover, and simplifying logistics and management costs.

[0034] According to some embodiments of this utility model, refer to Figure 5 The insulating coating 12 does not cover the connecting ring 132 and the pressure relief valve plate 13, leaving the pressure relief valve plate 13 exposed. This exposes both the connecting ring 132 and the pressure relief valve plate 13, achieving the following technical effects: It better maintains the design function of the pressure relief valve 13; it allows for more precise bursting, ensuring that the thickness and mechanical properties of the entire pressure relief valve 13 remain unchanged, enabling it to open more accurately and promptly at the design pressure value, thus achieving better controllable pressure relief; it makes the rupture of the pressure relief valve 13 more controllable, ensuring that during thermal runaway, the rupture will strictly occur along the predetermined location of the connecting ring 132 (e.g., where the connecting ring 132 has a notch 133 structure, this is the location of the notch 133), forming the expected opening, efficiently exporting energy and matter from inside the battery, and avoiding the generation of uncontrollable fragments.

[0035] According to some embodiments of this utility model, refer to Figure 2 and Figure 3 A notch 133 is formed at the connecting ring 132, and the notch 133 is a groove structure recessed into the interior of the battery casing 10. By directly setting the notch 133 on the casing 11, the pressure relief valve 13 structure can be easily formed, and the structure located on the inner circumference of the notch 133 forms the pressure relief valve plate 13. The structural strength at the notch 133 position of the casing 11 is relatively weaker than other places. In the event of battery thermal runaway, the notch 133 position of the casing 11 will crack first, and the pressure relief valve plate 13 will open the pressure relief port, thereby allowing the high-temperature gas inside the battery casing 10 to be discharged from the pressure relief port, which can achieve directional pressure relief.

[0036] According to some embodiments of this utility model, refer to Figures 2-5 The pressure relief valve 13 is circular. By making the pressure relief valve 13 circular, the structure of the pressure relief valve 13 can be simplified, and sharp structures on the outer edge of the pressure relief valve 13 can be avoided, which would affect the pressure relief effect.

[0037] According to some embodiments of this utility model, refer to Figure 2 and Figure 3The edge of the insulating coating 12 near the connecting ring 132 is called the coating edge, and the distance between the coating edge and the connecting ring 132 is D, 0.5mm ≤ D ≤ 5mm. For example, the distance D between the coating edge and the connecting ring 132 can be 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 0.5mm, 4.5mm, 5mm, etc. By setting the distance between the coating edge of the insulating coating 12 and the connecting ring 132 to 0.5mm to 5mm, the insulating coating 12 can be better prevented from covering the connecting ring 132, and the exposed area of ​​the core area of ​​the pressure relief valve 13 (i.e., the connecting ring 132) can be better guaranteed. This ensures that the connecting ring 132 of the pressure relief valve 13 can be broken and opened normally, and avoids a large exposed area on the outer surface of the housing 11, thus also ensuring the insulation and protective performance of the insulating coating 12.

[0038] According to some embodiments of this utility model, refer to Figure 2 and Figure 3 The insulating coating 12 includes a coating body region 121 and a coating thinning region 122. The thickness of the coating thinning region 122 is less than the thickness of the coating body region 121. The inner and / or outer peripheral sides of the connecting ring 132 are provided with the coating thinning region 122. The coating thinning region 122 is formed as an annulus extending circumferentially along the connecting ring 132.

[0039] For example, when the outer surface of the pressure relief valve plate 13 is not covered with the insulating coating 12, a coating thinning area 122 is provided on the outer periphery of the connecting ring 132; when the outer surface of the pressure relief valve plate 13 is covered with the insulating coating 12, a coating thinning area 122 is provided on the inner periphery of the connecting ring 132 and a coating thinning area 122 is provided on the outer periphery of the connecting ring 132. By providing a thinner coating thinning area 122 near the connecting ring 132 of the insulating coating 12, the coating thinning area 122 defines a safety buffer zone. Even if there are slight process fluctuations in spraying or masking, it can ensure that the sensitive connecting ring 132 or the area with the notch 133, which is not allowed to have any coating, is clean. This can provide process tolerance for the spraying process of the insulating coating 12. It physically isolates the thicker coating body area 121 from the functional area of ​​the pressure relief valve 13 (i.e., the connecting ring 132 or the notch 133 structure), and can better avoid the influence of the insulating coating 12 on the function of the pressure relief valve 13, thus better ensuring the reliability of the function of the pressure relief valve 13.

[0040] According to some embodiments of this utility model, refer to Figure 2 and Figure 3 The thickness of the coating thinning region 122 gradually decreases in the radial direction along and close to the connecting ring 132. By gradually reducing the thickness of the coating thinning region 122 in the direction close to the connecting ring 132, the following technical effects can be achieved: First, reduce stress concentration in the insulating coating 12 to prevent cracking and peeling: Avoid sharp "cliff" edges at the termination boundary of the insulating coating 12. If the edge of the insulating coating 12 is vertical and sharp, this area will become a huge stress concentration point. Under the long-term vibration and thermal cycling of the battery, due to the difference in thermal expansion coefficients between the insulating coating 12 and the metal substrate, stress will accumulate here, which can easily cause the insulating coating 12 to crack, lift or peel off in large areas starting from the edge. The thickness of the coating thinning area 122 gradually decreases, so that the smooth thickness transition forms a gentle "slope", which can effectively disperse and release stress, greatly improve the adhesion and long-term reliability of the insulating coating 12 at the edge, and ensure the integrity of the insulation barrier. Second, improve insulation withstand voltage performance and avoid local electric field concentration: improve the electrical insulation strength of the edge area to prevent partial discharge. In high voltage systems, the electric field will concentrate at sharp edges. A steep coating edge will distort the electric field lines, causing the electric field strength in that area to be much higher than in other areas, which may trigger partial discharge (corona). Over time, it will gradually erode and damage the insulation material. The thickness of the coating thinning area 122 gradually decreases, making the thickness transition smoother and the electric field distribution more uniform, eliminating potential electric field concentration points, thereby improving the overall insulation withstand voltage level and long-term stability. Third, the coating thinning zone 122 defines a safety buffer zone, which can ensure that even if there are slight process fluctuations in spraying or masking, the sensitive connecting ring 132 or score 133 area, which is not allowed to have any coating, is clean. It can provide process tolerance for the spraying process of the insulating coating 12. It physically isolates the thick coating body area 121 from the functional area of ​​the pressure relief valve 13 (i.e., the connecting ring 132 or score 133 structure), and can better avoid the influence of the insulating coating 12 on the function of the pressure relief valve 13, and can better ensure the reliability of the function of the pressure relief valve 13. Fourth, it improves the mechanical properties and environmental resistance of the insulating coating 12: it enhances the insulation coating 12's resistance to mechanical impact and environmental corrosion. The smooth transition edges have better mechanical toughness than sharp edges, making it less prone to damage from collisions or scratches. At the same time, it also reduces the risk of moisture and corrosive media penetrating the bottom channels of the insulating coating 12 due to edge cracking.

[0041] According to some embodiments of this utility model, refer to Figure 2 and Figure 3The radial width of the coating thinning region 122 is d, and the thickness of the coating body region 121 is T, where 1mm ≤ d ≤ 3mm or d ≥ 5T. For example, the radial width d of the coating thinning region 122 can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, etc. For example, the radial width d of the coating thinning region 122 can be 5T, 6T, 7T, 8T, 9T, 10T, etc. By ensuring that the radial width d of the coating thinning region 122 is between 1mm and 3mm or not less than 5T, sufficient length can be ensured for a smooth transition, avoiding an overly abrupt transition that would lose the stress release effect, and also preventing the transition region from being too long, resulting in excessive loss of effective insulation area.

[0042] According to some embodiments of this utility model, refer to Figure 2 and Figure 3 The thickness of the coating body region 121 is T, which is 50μm ≤ T ≤ 300μm. For example, the thickness T of the coating body region 121 can be 50μm, 100μm, 150μm, 200μm, 250μm, 300μm, etc. By setting the thickness T of the coating body region 121 to 50μm to 300μm, the insulation strength of the insulating coating 12 can be reliably guaranteed within this range, while avoiding cracking or heat dissipation problems caused by an excessively thick insulating coating 12.

[0043] Reference Figure 1 and Figure 2 According to a second aspect embodiment of the present invention, a battery cell 100 includes a battery casing 10 and an electrode assembly 20 according to the first aspect embodiment of the present invention, wherein the electrode assembly 20 is disposed inside the battery casing 10.

[0044] The electrode assembly 20 may include a positive electrode, a negative electrode, and an insulating separator, with the insulating separator disposed between the positive and negative electrode. The electrode assembly 20 includes a positive electrode tab and a negative electrode tab, and the battery casing 10 may have a positive electrode post and a negative electrode post, with the positive electrode tab connected to the positive electrode post and the negative electrode tab connected to the negative electrode post.

[0045] According to the embodiment of the present utility model, the battery cell 100, by providing the above-mentioned battery casing 10, the battery casing 10 replaces the blue film with an insulating coating 12 and the insulating coating 12 does not cover the connection between the pressure relief valve 13 and the housing 11, which provides insulation protection for the battery and makes the burst pressure value of the pressure relief valve 13 accurate and reliable, which is beneficial to improving the safety of the battery.

[0046] Reference Figure 6 The battery device 200 according to the third aspect of the present invention includes: a housing 30 and a battery cell 100 according to the second aspect of the present invention described above. The battery cell 100 is disposed inside the housing 30, and there may be multiple battery cells 100.

[0047] For example, battery device 200 can be used in energy storage devices.

[0048] According to the battery device 200 of this utility model embodiment, by setting the above-mentioned battery cell 100, the battery casing 10 of the battery cell 100 is replaced by an insulating coating 12 instead of a blue film, and the insulating coating 12 does not cover the connection between the pressure relief valve 13 and the casing 11. While providing insulation protection for the battery, it can make the burst pressure value of the pressure relief valve 13 accurate and reliable, which is beneficial to improving the safety of the battery.

[0049] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0050] In the description of this utility model, "first feature" and "second feature" may include one or more of the features.

[0051] In the description of this utility model, "multiple" means two or more.

[0052] In the description of this utility model, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or it may include the first and second features not being in direct contact but being in contact through another feature between them.

[0053] In the description of this utility model, the terms "above", "over" and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicate that the first feature is at a higher horizontal level than the second feature.

[0054] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0055] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery casing, characterized in that, include: The housing has a pressure relief port, and a pressure relief valve is provided at the pressure relief port. The pressure relief valve includes a pressure relief valve plate and a connecting ring. The connecting ring is arranged around the pressure relief valve plate and connected between the outer peripheral wall of the pressure relief valve plate and the inner peripheral wall of the pressure relief port. The thickness of at least a portion of the connecting ring is less than the thickness of the housing and the thickness of the pressure relief valve plate. An insulating coating is provided on the outer surface of the housing, and the insulating coating does not cover the connecting ring, so that the connecting ring is exposed.

2. The battery casing according to claim 1, characterized in that, The insulating coating covers the outer surface of the pressure relief valve plate; or, the insulating coating does not cover the pressure relief valve plate, leaving the pressure relief valve plate exposed.

3. The battery casing according to claim 1, characterized in that, The connecting ring has grooves; and / or the pressure relief valve is circular.

4. The battery casing according to claim 1, characterized in that, The edge of the insulating coating near the connecting ring is the coating edge, and the distance between the coating edge and the connecting ring is D, where 0.5mm≤D≤5mm.

5. The battery casing according to any one of claims 1-4, characterized in that, The insulating coating includes a coating body area and a coating thinning area. The thickness of the coating thinning area is less than the thickness of the coating body area. The coating thinning area is provided on the inner and / or outer circumferential sides of the connecting ring. The coating thinning area is formed as an annular shape extending circumferentially along the connecting ring.

6. The battery casing according to claim 5, characterized in that, The thickness of the coating thinning zone gradually decreases in the radial direction of the connecting ring and in the direction close to the connecting ring.

7. The battery casing according to claim 5, characterized in that, The radial width of the coating thinning zone is d, and the thickness of the coating main zone is T, where 1mm≤d≤3mm or d≥5T.

8. The battery casing according to claim 5, characterized in that, The thickness of the main coating area is T, where 50μm≤T≤300μm.

9. A single battery cell, characterized in that, include: Battery casing according to any one of claims 1-8; An electrode assembly is disposed within the battery casing.

10. A battery device, characterized in that, include: Box; According to claim 9, the battery cell is disposed within the housing.

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