Battery, battery pack and energy storage system

Abstract

The utility model provides a battery, a battery pack and an energy storage system, and belongs to the technical field of batteries. A battery cover plate and a battery shell of the battery are connected and matched to form a closed cavity for accommodating a battery cell. The battery cover plate comprises a cover plate and an insulating base plate which are laminated, a valve hole penetrating through the cover plate and the insulating base plate, and an anti-explosion valve for sealing the valve hole, the explosion-proof valve comprises a valve plate and an insulating fireproof layer which are sequentially distributed along the axis direction of the valve hole, the insulating fireproof layer is closer to the battery core relative to the valve plate, the insulating fireproof layer is provided with a tearing line, the tearing line comprises a plurality of holes which are arranged at intervals, and the insulating fireproof layer is a fireproof crack piece which can be cracked based on the tearing line and can be expanded outwards along the radial direction. And the fireproof splinters can cover metal at the valve hole when being unfolded, which comprises at least one of the inner wall of the valve hole, the plate surface of the cover plate located at the outer side of the valve hole and the rupture valve plate, so that the risk of fire caused by friction between the active substance and the metal at the valve hole is reduced, and the thermal runaway of the aggravated battery cell is avoided.

Description

Technical Field

[0001] The embodiments of the utility model relate to the field of battery technology, and in particular to batteries, battery packs and energy storage systems. Background Art

[0002] Secondary batteries such as lithium-ion batteries usually include: battery cells, battery shells and battery covers. The battery cover is welded to the battery shell to form a sealed cavity, and the battery cells are contained in the sealed cavity. When an exothermic side reaction occurs inside the battery cell and causes heat accumulation, it will not only cause combustion or explosion, but also produce toxic gases at the moment of fire. Therefore, an explosion-proof valve is usually set on the battery cover to timely release the pressure inside the battery and discharge toxic gases.

[0003] In the related art, a battery cover is provided with a valve hole, and the explosion-proof valve comprises a valve plate, which is arranged inside the valve hole and has notches on the valve plate, so that when the explosion-proof valve is opened, the valve plate ruptures along the notches to release pressure and gas.

[0004] Since the valve plate and the cover plate in the battery cover are usually made of aluminum, when the explosion-proof valve is opened, the gas will be sprayed out with some active substances inside the battery cell, causing it to rub against the metal exposed at the valve hole, such as the aluminum inner wall of the valve hole, the ruptured aluminum valve plate, etc. This may cause heat accumulation and friction fire, thereby aggravating thermal runaway of the battery cell. Utility Model Content

[0005] The embodiments of the present utility model provide a battery, a battery pack and an energy storage system, which can solve the technical problems existing in the related technologies. Specifically, the technical solution is as follows.

[0006] On the one hand, a battery is provided, comprising: a battery cover, a battery shell and a battery cell, wherein the battery cover is connected to the battery shell and cooperates to form a closed cavity to accommodate the battery cell; the battery cover comprises: a cover plate and an insulating pad arranged in a stacked manner, a valve hole penetrating the cover plate and the insulating pad, and an explosion-proof valve closing the valve hole; the explosion-proof valve comprises: a valve sheet and an insulating fireproof layer distributed in sequence along the axial direction of the valve hole, and the insulating fireproof layer is closer to the battery cell than the valve sheet, the insulating fireproof layer has a tear line, the tear line comprises a plurality of holes arranged at intervals, and the insulating fireproof layer can be ruptured based on the tear line and form fireproof cracks that expand outward in a radial direction.

[0007] The battery provided by the embodiment of the utility model has an explosion-proof valve with an insulating fireproof layer added on the basis of the valve plate, and the insulating fireproof layer has a tear line formed by a plurality of holes arranged at intervals. When the thermal runaway of the battery cell causes the internal pressure of the battery to be too high and exceeds the opening pressure of the explosion-proof valve, the insulating fireproof layer ruptures based on its tear line and forms fireproof cracks that expand outward in the radial direction (which can also be understood as expanding in the direction close to the inner wall of the valve hole), and the valve plate also ruptures accordingly. Since the insulating fireproof layer is closer to the battery cell than the valve plate, the fireproof cracks can cover the metal exposed at the valve hole when they expand outward in the radial direction. The metal includes at least one of the inner wall of the valve hole, the plate surface of the cover plate located outside the valve hole, and the ruptured valve plate, thereby reducing or even avoiding the risk of fire caused by friction between the active substances discharged from the battery cell and the metal at the valve hole, avoiding aggravating the thermal runaway of the battery cell, and improving the safety of battery use.

[0008] In addition, when the battery cell is in thermal runaway, if the active substances discharged from the battery cell rub against the metal at the valve hole and cause a fire, it will also pose a safety threat to the adjacent battery cells. The embodiment of the utility model reduces or even avoids the sparks generated by the friction between the active substances discharged from the battery cell and the metal at the valve hole by setting an insulating fireproof layer in the explosion-proof valve, which can also avoid the safety threat to the adjacent battery cells. It can be seen that the explosion-proof valve involved in the embodiment of the utility model makes the valve plate and the insulating fireproof layer cooperate to effectively inhibit the friction fire when the battery cell opens the valve, reduce the hazard of thermal runaway of the battery cell, and the explosion-proof valve also has the advantages of simple structure, simple molding and preparation process, low cost, and excellent safety and practicality.

[0009] In some embodiments, the valve sheet is located in the valve hole, and the insulating fireproof layer is located on the surface of the insulating pad facing the battery core.

[0010] Exemplarily, the insulating fireproof layer is an insulating fireproof film material with ductility or an insulating fireproof film material with plasticity.

[0011] In some embodiments, the inner wall of the valve hole has an insulating fireproof coating, the insulating fireproof layer is located on the surface of the cover plate facing away from the insulating pad, and the valve plate is connected to the surface of the cover plate facing away from the insulating pad and covers the insulating fireproof layer.

[0012] Exemplarily, the insulating fireproof layer is an insulating fireproof film material with ductility, an insulating fireproof film material with plasticity, or an insulating fireproof coating.

[0013] In some embodiments, the insulating fireproof layer is stacked on the surface of the valve sheet facing the battery core to cooperate to form a composite explosion-proof valve, and the composite explosion-proof valve is arranged in the valve hole.

[0014] Exemplarily, the insulating fireproof layer is an insulating fireproof film material with ductility, an insulating fireproof film material with plasticity, or an insulating fireproof coating.

[0015] In some embodiments, the tear line is a closed loop structure, and the tear line separates the insulating fireproof layer into an inner ring portion and an outer ring portion, and the area of ​​the inner ring portion is smaller than the area of ​​the valve plate. By making the area of ​​the inner ring portion of the insulating fireproof layer smaller than the area of ​​the valve plate, it is possible to ensure that the area of ​​the outer ring portion of the insulating fireproof layer is large enough, so as to cover the metal exposed at the valve hole based on the sufficient area.

[0016] Exemplarily, the tear line has a shape of a circle, an ellipse, a rectangle or a regular polygon.

[0017] In some embodiments, the valve sheet has a notch, and the projection of the tear line on the valve sheet coincides with the notch.

[0018] On the other hand, a battery pack is provided, the battery pack comprising a plurality of any of the above-mentioned batteries, the plurality of the batteries being connected in series or in parallel. The battery pack provided by the embodiment of the utility model has all the advantages of the battery provided by the embodiment of the utility model.

[0019] On the other hand, an energy storage system is provided, the energy storage system comprising a power converter and at least one battery pack as described above; the power converter is used to convert the voltage output by the battery pack into power and output it to a power grid or a load, and / or to convert the voltage output by an external power source into power and output it to the battery pack. The energy storage system provided by the embodiment of the utility model has all the advantages of the battery or battery pack provided by the embodiment of the utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A diagram of an exemplary battery assembly provided for an embodiment of the utility model;

[0021] Figure 2 An exploded view of an exemplary battery provided for an embodiment of the utility model;

[0022] Figure 3 A partial exploded view of an exemplary battery cover provided by an embodiment of the utility model;

[0023] Figure 4 A schematic diagram of the structure of an exemplary valve plate provided in an embodiment of the utility model;

[0024] Figure 5 A schematic structural diagram of an exemplary insulating fireproof layer provided in an embodiment of the utility model;

[0025] Figure 6A schematic diagram of an exemplary explosion-proof valve arrangement provided in an embodiment of the utility model;

[0026] Figure 7 for Figure 6 A bottom view of the explosion-proof valve shown before rupture;

[0027] Figure 8 for Figure 6 A bottom view of the explosion-proof valve after rupture;

[0028] Fig. 9 for Figure 6 The explosion-proof valve is shown in a diagram showing the expanded state of the insulating fireproof layer as viewed from a bottom up angle after being ruptured;

[0029] Fig.10 for Figure 6 The explosion-proof valve is shown in a top-down view of the expanded state of the insulating fireproof layer after it is ruptured;

[0030] Fig.11 A schematic diagram of another exemplary explosion-proof valve arrangement provided in an embodiment of the utility model;

[0031] Fig.12 Based on Fig.11 The preparation flow chart of the explosion-proof valve shown;

[0032] Fig.13 A schematic diagram of another exemplary explosion-proof valve arrangement provided in an embodiment of the utility model;

[0033] Fig.14 Based on Fig.13 A bottom view of a type of explosion-proof valve shown;

[0034] Fig.15 Based on Fig.13 A bottom view of another type of explosion-proof valve is shown;

[0035] Fig.16 for Fig.15 A top view of the explosion proof valve is shown after rupture.

[0036] The reference numerals represent:

[0037] 100. Battery cover;

[0038] 11. Cover plate; 12. Insulating pad; 13. Valve hole; 130. Insulating fireproof coating; 131. Periphery of the valve hole;

[0039] 14. Explosion-proof valve;

[0040] 141, valve plate; 1410, notch; 1411, valve plate split; 142, insulating fireproof layer; 1420, tear line; 1421, fireproof split;

[0041] 15. Negative pole; 16. Positive pole; 17. Liquid injection hole;

[0042] 200. Battery housing;

[0043] 300. Battery cell. DETAILED DESCRIPTION

[0044] In the description of the embodiments of the present invention, it should be understood that the terms "inside", "outside", "top", "bottom", "vertical", "horizontal", "height", "depth" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. When the product is placed in different postures, the orientation may change, and therefore cannot be understood as a limitation on the embodiments of the present invention.

[0045] For secondary batteries such as lithium-ion batteries, they usually include: battery cells, battery shells and battery cover plates. The battery cover plates are welded to the battery shells to form a sealed cavity, and the battery cells are contained in the sealed cavity. When exothermic side reactions occur inside the battery cells and heat accumulates, it will not only cause combustion or explosion, but also produce toxic gases at the moment of fire. Therefore, an explosion-proof valve is usually set on the battery cover plate to timely release the pressure inside the battery and discharge toxic gases.

[0046] In the related art, a valve hole is provided on the battery cover, and the explosion-proof valve includes a valve plate, which is arranged inside the valve hole and has notches on the valve plate, so that when the explosion-proof valve is opened, the valve plate ruptures along the notches to release pressure and gas.

[0047] Since the valve plate and the cover plate in the battery cover are usually made of aluminum, when the explosion-proof valve is opened, the gas will be sprayed out with some active substances inside the battery cell, causing it to rub against the metal exposed at the valve hole, such as the aluminum inner wall of the valve hole, the ruptured aluminum valve plate, etc. This may cause heat accumulation and friction fire, thereby aggravating thermal runaway of the battery cell.

[0048] In view of the technical problems existing in the related art, the present utility model provides a battery, as shown in the attached Figure 1 and attached Figure 2 As shown, the battery comprises: a battery cover 100, a battery shell 200 and a battery cell 300. The battery cover 100 is connected to the battery shell 200 and cooperates to form a closed cavity to accommodate the battery cell 300. Figure 3As shown, the battery cover 100 includes: a cover 11 and an insulating pad 12 arranged in a stacked manner, the cover 11 is located above the insulating pad 12, a valve hole 13 passes through the cover 11 and the insulating pad 12, and an explosion-proof valve 14 closes the valve hole 13, and the explosion-proof valve 14 includes: a valve sheet 141 and an insulating fireproof layer 142 sequentially distributed along the axial direction of the valve hole 13, and the insulating fireproof layer 142 is closer to the battery cell 300 than the valve sheet 141, and further combined Figure 5 As shown, the insulating fireproof layer 142 has a tear line 1420, and the tear line 1420 includes a plurality of holes arranged at intervals. The insulating fireproof layer 142 can be broken based on the tear line 1420 and form fireproof split pieces 1421 that expand outwardly in a radial direction.

[0049] The "expanding outward in the radial direction" involved in the embodiment of the utility model refers to starting from the central axis of the valve hole 13 and expanding toward the periphery around the central axis of the valve hole 13. When the fireproof split piece 1421 is expanded outward in the radial direction, the fireproof split piece 1421 can cover the metal exposed at the valve hole 13, wherein the metal involved here includes at least one of the inner wall of the valve hole 13, the plate surface of the cover plate 11 located outside the valve hole 13, and the broken valve piece 141.

[0050] The explosion-proof valve 14 of the battery provided by the embodiment of the utility model has an insulating fireproof layer 142 added to the valve plate 141. The insulating fireproof layer 142 has a tear line 1420 formed by a plurality of holes arranged at intervals. When the battery cell 300 thermally runs away and the internal pressure of the battery is too large and exceeds the opening pressure of the explosion-proof valve 14, the insulating fireproof layer 142 ruptures based on the tear line 1420 and forms a fireproof split 1421 that expands outward in the radial direction (it can also be understood as expanding in the direction close to the inner wall of the valve hole 13), and the valve plate 141 also breaks. Since the insulating fireproof layer 142 is closer to the battery cell 300 than the valve sheet 141, the fireproof crack 1421 can cover the metal exposed at the valve hole 13 when it expands outward in the radial direction. The metal includes at least one of the inner wall of the valve hole 13, the plate surface of the cover plate 11 located outside the valve hole 13, and the ruptured valve sheet 141, thereby reducing or even avoiding the risk of fire caused by friction between the active substances discharged from the battery cell 300 and the metal at the valve hole 13, avoiding aggravating the thermal runaway of the battery cell 300, and improving the safety of battery use.

[0051] In addition, when the battery cell 300 is in thermal runaway, if the active substances discharged from the battery cell 300 rub against the metal at the valve hole 13 and cause a fire, it will also pose a safety threat to the adjacent battery cells 300. The embodiment of the utility model reduces or even avoids the generation of sparks due to the friction between the active substances discharged from the battery cell 300 and the metal at the valve hole 13 by providing an insulating fireproof layer 142 in the explosion-proof valve 14, which can also avoid the safety threat to the adjacent battery cells 300.

[0052] It can be seen that the explosion-proof valve 14 involved in the embodiment of the utility model enables the valve plate 141 to cooperate with the insulating fireproof layer 142 to effectively suppress the friction fire when the battery cell 300 opens the valve, and reduce the hazard of thermal runaway of the battery cell 300. In addition, the explosion-proof valve 14 also has the advantages of simple structure, simple molding and preparation process, low cost, and excellent safety and practicality.

[0053] The valve plate 141 involved in the embodiment of the utility model can adopt the currently known explosion-proof valve plate structure, which is not specifically limited here. It should be noted that, as shown in the attached Figure 4 As shown, the valve sheet 141 involved in the embodiment of the utility model has a notch 1410 (also called a bursting notch 1410), so that when the explosion-proof valve 14 is opened, the valve sheet 141 ruptures along the notch 1410, thereby releasing the pressure and gas inside the battery.

[0054] For the insulating fireproof layer 142 involved in the explosion-proof valve 14, it can be an independent membrane material structure or a coating structure attached to other components. In addition, the size of the insulating fireproof layer 142 can at least meet the requirement that it can completely cover the valve hole 13. The outer contour shape of the insulating fireproof layer 142 can be any geometric shape. For example, a regular geometric shape that is easy to form and prepare can be adopted, which includes but is not limited to: circle, ellipse, rectangle, regular polygon, etc.

[0055] By providing a plurality of holes arranged at intervals on the insulating fireproof layer 142, an easily ruptured tear line 1420 is formed. The shape of the hole forming the tear line 1420 can be any geometric shape, and the shapes of the plurality of holes can be the same or different. Exemplary, some holes that are easy to form and prepare include but are not limited to: round holes, strip holes, arc holes, etc. The plurality of holes forming the tear line 1420 are arranged at intervals, wherein the spacing between any two holes can be the same or different. In order to simplify the preparation process of the tear line 1420, the spacing between any two holes can be the same.

[0056] In addition, on the basis of ensuring that the tear line 1420 is easily broken under the rupture pressure, the area of ​​the hole can be made as small as possible, which is conducive to making the area of ​​the insulating fireproof region of the insulating fireproof layer 142 correspondingly larger, thereby optimizing the fireproof effect of the insulating fireproof layer 142.

[0057] In an embodiment of the utility model, the insulating fireproof layer 142 is configured so that after the tear line 1420 breaks, the multiple fireproof fragments 1421 formed can expand toward the direction close to the inner wall of the valve hole 13, so that the fireproof fragments 1421 can cover the metal exposed at the valve hole 13, thereby reducing or even completely avoiding the probability of sparks formed by friction between the active substance and the metal exposed at the valve hole 13.

[0058] When the insulating fireproof layer 142 is an independent membrane structure, the insulating fireproof layer 142 can be ductile, that is, non-brittle, so that it can be folded or bent without breaking. In some examples, the insulating fireproof layer 142 is an insulating fireproof membrane material with ductility, thereby ensuring that the fireproof cracks 1421 formed by the insulating fireproof layer 142 can be fully unfolded without secondary rupture, thereby ensuring that it can cover the exposed metal at the valve hole 13.

[0059] Taking into account that the insulating fireproof layer 142 also needs to have high temperature resistance (to give it fireproof properties) and electrical insulation (to prevent fire caused by friction with active substances), in addition to its ductility requirements, some ductile film materials suitable for the insulating fireproof layer 142 of the embodiment of the utility model include but are not limited to: mica paper (withstands temperature of 500℃-1000℃), aluminum silicate ceramic fiber paper (withstands temperature of 1260℃-1400℃), etc.

[0060] The embodiment of the utility model also expects that the fireproof cracks 1421 of the insulating fireproof layer 142 can cover at least one of the inner wall of the valve hole 13, the plate surface of the cover plate located outside the valve hole 13, and the ruptured valve plate 141 after being unfolded. For example, it can cover the inner wall of the valve hole 13, the plate surface of the cover plate located outside the valve hole 13, and the ruptured valve plate 141 at the same time, so as to achieve a more reliable anti-friction fire effect.

[0061] The embodiment of the utility model can further ensure that the above functions are reliably realized by adjusting the structure of the tear line 1420 and the layout of the tear line 1420 on the insulating fireproof layer 142 .

[0062] In some examples, such as the attached Figure 5 As shown, the tear line 1420 is a closed loop structure, so as to separate the insulating fireproof layer 142 into an inner ring portion and an outer ring portion, and the area of ​​the inner ring portion is smaller than the area of ​​the valve plate 141. The tear line 1420 is a closed loop structure, which means that the tear line 1420 is connected end to end to form a ring structure, the inner ring portion refers to the portion of the insulating fireproof layer 142 located inside the tear line 1420, and the outer ring portion refers to the portion of the insulating fireproof layer 142 located outside the tear line 1420.

[0063] In the embodiment of the utility model, the axis of the insulating fireproof layer 142 can coincide with the axis of the valve plate 141, so that the inner ring portion of the insulating fireproof layer 142 corresponds to the middle area of ​​the valve plate 141. After the insulating fireproof layer 142 is broken based on the tear line 1420, its fireproof split 1421 is mainly composed of the outer ring portion of the insulating fireproof layer 142. In the embodiment of the utility model, the area of ​​the inner ring portion of the insulating fireproof layer 142 is smaller than the area of ​​the valve plate 141, so that the area of ​​the outer ring portion of the insulating fireproof layer 142 is ensured to be large enough, so as to cover the metal exposed at the valve hole 13 based on the sufficient area.

[0064] In other examples, the area of ​​the inner ring can be made small enough so that a large number of fireproof splits 1421 can be formed after the insulating fireproof layer 142 is broken based on the tear line 1420, and the areas of the multiple fireproof splits 1421 can be made as uniform as possible. For example, the ratio of the area of ​​the valve plate 141 to the area of ​​the inner ring can be made 2:1 to 10:1.

[0065] For the tear line 1420 of the closed-loop structure involved above, the shape of the tear line 1420 can be a regular geometric shape or an irregular geometric shape. In order to simplify the preparation process of the tear line 1420, the shape of the tear line 1420 can be a regular geometric shape, which includes but is not limited to: circle, ellipse, rectangle or regular polygon, etc.

[0066] As attached Figure 5 As shown, taking the tear line 1420 as a circle for example, the central axis of the circle corresponding to the tear line 1420 coincides with the central axis of the valve plate 141 , and the diameter of the circle corresponding to the tear line 1420 is smaller than the diameter of the valve plate 141 .

[0067] On the basis of the above-mentioned insulating fireproof layer 142 , regarding the assembly method of the insulating fireproof layer 142 and the valve sheet 141 in the battery cover 100 , reference may be made to the following exemplary scheme.

[0068] In embodiment (1), an explosion-proof valve 14 is provided, as shown in the attached Figure 6 -Attached Figure 8 As shown, the valve plate 141 is located in the valve hole 13 , and the insulating fireproof layer 142 is located on the surface of the insulating pad 12 facing the battery cell 300 .

[0069] For implementation scheme (1), the insulating fireproof layer 142 is arranged independently of the valve plate 141, and the valve plate 141 is connected and arranged in the valve hole 13 corresponding to the cover plate 11. The arrangement of the valve plate 141 in the valve hole 13 can adopt a currently known scheme, which will not be repeated here. Among them, the insulating fireproof layer 142 can adopt an insulating fireproof film material with ductility or an insulating fireproof film material with plasticity. The insulating fireproof film material with ductility is, for example, mica paper, aluminum silicate ceramic fiber paper, etc., and the insulating fireproof film material with plasticity is, for example, asbestos cloth, etc.

[0070] The tear line 1420 on the insulating fireproof layer 142 can be a closed loop structure such as a circle, an ellipse, a regular polygon, etc. For example, the tear line 1420 is a circle, the central axis of the circle corresponding to the tear line 1420 coincides with the central axis of the valve plate 141, and the diameter of the circle corresponding to the tear line 1420 is smaller than the diameter of the valve plate 141.

[0071] The operating mechanism of implementation scheme (1) is as follows: when the battery cell 300 thermally runs away and causes its internal pressure to be too high, causing the explosion-proof valve 14 to open (that is, when the internal pressure of the battery cell 300 is too high and causes the valve to blow out), the insulating fireproof layer 142 is first ruptured based on its tear line 1420, and forms a fireproof splinter 1421 that expands toward the inner wall of the valve hole 13. The valve sheet 141 is then ruptured based on its notch 1410. As a result, when the fireproof splinter 1421 expands outward, it can cover the metal exposed at the valve hole 13, which includes at least one of the inner wall of the valve hole 13, the plate surface of the cover plate 11 located outside the valve hole 13, and the ruptured valve sheet 141, thereby reducing or even avoiding the friction between the active substances discharged from the battery cell 300 and the metal at the valve hole 13 to ignite, thereby slowing down the thermal runaway of the battery cell 300. Among them, the state of the fireproof splinter 1421 when it expands outward can be seen in Figure 8 , Fig. 9 and Fig.10 ,Depend on Figure 8 and Fig. 9 As shown, both show the fireproof split 1421 spreading outward and covering the metal inner wall of the valve hole 13 from a bottom-up perspective. Fig.10 The top view shows that when the fireproof split piece 1421 is expanded outward, it not only covers the metal inner wall of the valve hole 13, but also covers the plate surface of the cover plate 11 located outside the valve hole 13, and some of the broken valve pieces 141 remaining on the cover plate 11 are also covered. It should be noted that Fig.10 The elliptical dotted line involved in the figure refers to the periphery 131 of the valve hole 13. Although it is covered by the fireproof split 1421, in order to more intuitively show the unfolded state of the fireproof split 1421, it is represented here by a dotted line.

[0072] In some embodiments (2), an explosion-proof valve 14 is provided, as shown in the attached Fig.11 -Attached Fig.12 As shown, the inner wall of the valve hole 13 has an insulating fireproof coating 130, the insulating fireproof layer 142 is located on the surface of the cover plate 11 facing away from the insulating pad 12, and the valve plate 141 is connected to the surface of the cover plate 11 facing away from the insulating pad 12 and covers the insulating fireproof layer 142.

[0073] For implementation (2), the insulating fireproof layer 142 can be arranged independently of the valve plate 141. For example, the preparation process of the explosion-proof valve 14 involved in implementation (2) can be found in Fig.12 First, the valve hole 13 is covered with an insulating fireproof layer 142, and then a valve plate 141 is provided to further cover the insulating fireproof layer 142. For example, the insulating fireproof layer 142 can be fixed between the valve plate 141 and the cover plate 11 by being pressed by the valve plate 141.

[0074] Of course, in implementation (2), the insulating fireproof layer 142 can also be stacked on the valve plate 141 so that the two are arranged in an integrated manner, and the insulating fireproof layer 142 can be connected to the valve plate 141 (of course, it can also be connected to the cover plate 11) by bonding, coating adhesion, etc., so as to achieve a fixed arrangement of the valve plate 141. As for the valve plate 141, it can be connected to the cover plate 11 by welding.

[0075] Compared with the related art, the difference of implementation scheme (2) is that an insulating fireproof coating 130 is provided on the inner wall of the valve hole 13, which is more excellent and reliable for improving the effect of the explosion-proof valve 14 in suppressing friction fire of the battery cell 300 when the valve is opened, and the valve plate 141 is not provided inside the valve hole 13, but the valve plate 141 is provided outside the valve hole 13, which is more advantageous for simplifying the assembly of the explosion-proof valve 14. Exemplarily, the thickness of the insulating fireproof coating 130 provided inside the valve hole 13 can be 0.2mm-0.5mm, which includes but is not limited to: 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, etc.

[0076] Of course, the valve plate 141 involved here is larger in size than the valve plate arranged inside the valve hole 13 to ensure effective coverage of the insulating fireproof layer 142.

[0077] When the insulating fireproof layer 142 is arranged independently relative to the valve plate 141, the insulating fireproof layer 142 can be made of an insulating fireproof film material with ductility or an insulating fireproof film material with plasticity. The insulating fireproof film material with ductility is, for example, mica paper, aluminum silicate ceramic fiber paper, etc., and the insulating fireproof film material with plasticity is, for example, asbestos cloth, etc. The tear line 1420 on the insulating fireproof layer 142 can be a closed loop structure such as a circle, an ellipse, a regular polygon, etc. For example, the tear line 1420 is a circle, the central axis of the circle corresponding to the tear line 1420 coincides with the central axis of the valve plate 141, and the diameter of the circle corresponding to the tear line 1420 is smaller than the diameter of the valve plate 141.

[0078] When the insulating fireproof layer 142 is stacked on the valve plate 141 so that the two are arranged in an integrated manner, the insulating fireproof layer 142 can be made of an insulating fireproof film material with ductility, an insulating fireproof film material with plasticity, or an insulating fireproof coating. The insulating fireproof layer 142 can be connected to the surface of the valve plate 141 facing the battery cell 300 by bonding. At this time, the insulating fireproof layer 142 can be made of an insulating fireproof film material with ductility (the tear line 1420 can be pre-set), and its specific arrangement method can be referred to above, which will not be repeated here. Alternatively, the insulating fireproof layer 142 can be obtained by bonding an insulating fireproof film material with plasticity to the surface of the valve plate 141 facing the cover plate 11 by ultrasonic welding, wherein some suitable insulating fireproof films with plasticity can be asbestos cloth (the insulating fireproof film material with plasticity can be pre-set with a tear line 1420). Alternatively, the insulating fireproof layer 142 can be formed by spraying an insulating fireproof coating onto the surface of the valve plate 141 facing the cover plate 11 and then etching to obtain the tear line 1420 .

[0079] The tear line 1420 on the various types of insulating fireproof layers 142 involved here can be a closed-loop structure such as a circle, an ellipse, a regular polygon, etc. For example, the tear line 1420 is a circle, and the central axis of the circle corresponding to the tear line 1420 coincides with the central axis of the valve plate 141, and the diameter of the circle corresponding to the tear line 1420 is smaller than the diameter of the valve plate 141.

[0080] Alternatively, tear line 1420 may correspond to notch 1410 on valve plate 141 (this includes that the shapes and sizes of the two are consistent, and tear line 1420 corresponds to notch 1410, that is, the projection of tear line 1420 on valve plate 141 coincides with notch 1410).

[0081] For the insulating fire-retardant coating 130 arranged on the inner wall of the valve hole 13, as an example, it can be formed by adhering the above-mentioned insulating fire-retardant layer 142 to the inner wall of the valve hole 13. As another example, the insulating fire-retardant coating can also be sprayed onto the inner wall of the valve hole 13. This method makes the preparation of the insulating fire-retardant coating 130 easier and more reliable. Unlike the above-mentioned insulating fire-retardant layer 142, the insulating fire-retardant coating 130 formed based on the insulating fire-retardant coating can have no ductility requirements, and can meet the requirements of high temperature resistance (to give it fire-retardant properties) and electrical insulation (to prevent friction with active substances to ignite).

[0082] Some insulating fire retardant coatings suitable for the insulating fire retardant coating 130 of the embodiment of the utility model may be ceramic coatings or insulating fire retardant coating products currently on the market.

[0083] The operating mechanism of implementation scheme (2) is as follows: when the thermal runaway of the battery cell 300 causes the internal pressure to be too high and the explosion-proof valve 14 to open, the gas and active substances discharged from the battery cell 300 first impact the inner wall of the valve hole 13. Since the inner wall of the valve hole 13 is provided with an insulating fireproof coating 130, the risk of fire caused by friction between the active substances discharged from the battery cell 300 and the metal inner wall of the valve hole 13 is avoided. Then, the insulating fireproof layer 142 first breaks based on its tear line 1420, and forms a fireproof splinter 1421 that expands outward in the radial direction. At the same time, the valve sheet 141 breaks based on its notch 1410, so that the fireproof splinter 1421 can cover the plate surface of the cover plate 11 located outside the valve hole 13 and / or the broken valve sheet 141 when it expands outward, thereby reducing or even avoiding the risk of fire caused by friction between the active substances discharged from the battery cell 300 and the metal outside the valve hole 13, and slowing down the thermal runaway of the battery cell 300.

[0084] In some embodiments (3), an explosion-proof valve 14 is provided, as shown in the attached Fig.13 -Attached Fig.15 As shown, the insulating fireproof layer 142 is stacked on the surface of the valve sheet 141 facing the battery cell 300 to form a composite explosion-proof valve 14 , and the composite explosion-proof valve 14 is arranged in the valve hole 13 .

[0085] In implementation scheme (3), the valve plate 141 and the insulating fireproof layer 142 are arranged in an integrated manner, and the formed composite explosion-proof valve 14 is connected to the inner wall of the valve hole 13 through the valve plate 141.

[0086] With respect to the above-mentioned embodiment (3), the insulating fireproof layer 142 can be made of an insulating fireproof film material with ductility, an insulating fireproof film material with plasticity, or an insulating fireproof coating. The insulating fireproof layer 142 can be connected to the surface of the valve plate 141 facing the battery cell 300 by bonding. At this time, the insulating fireproof layer 142 can be made of an insulating fireproof film material with ductility (the tear line 1420 can be pre-set). The specific arrangement method can be referred to above and will not be repeated here. Alternatively, the insulating fireproof layer 142 can be obtained by stacking and arranging the insulating fireproof film material with plasticity on the surface of the valve plate 141 facing the cover plate 11 by ultrasonic welding, wherein some suitable insulating fireproof film materials with plasticity can be asbestos cloth (the insulating fireproof film materials with plasticity can be pre-set with a tear line 1420). Alternatively, the insulating fireproof layer 142 can be formed into an insulating fireproof coating by spraying an insulating fireproof coating onto the surface of the valve plate 141 facing the cover plate 11, and then etching to obtain the tear line 1420.

[0087] In some examples, such as the attached Fig.14 As shown, the tear line 1420 on the various insulating fireproof layers 142 involved in implementation scheme (3) can be a closed-loop structure shape such as a circle, an ellipse, a regular polygon, etc. For example, the tear line 1420 is a circle, and the central axis of the circle corresponding to the tear line 1420 coincides with the central axis of the valve plate 141, and the diameter of the circle corresponding to the tear line 1420 is smaller than the diameter of the valve plate 141.

[0088] In other examples, such as the Fig.15 As shown, the tear lines 1420 on the various types of insulating fireproof layers 142 involved in implementation scheme (3) may also correspond to the notches 1410 on the valve plate 141 (this includes that the shapes and sizes of the two are consistent, and the tear lines 1420 correspond to the notches 1410, that is, the projection of the tear lines 1420 on the valve plate 141 coincides with the notches 1410). Since the insulating fireproof layer 142 is stably combined with the valve plate 141, when the tear lines 1420 correspond to the notches 1410, after the explosion-proof valve 14 is broken, the fireproof splinters 1421 formed by the insulating fireproof layer 142 can always stably cover the splinters formed after the valve plate 141 is broken, and it is also possible to further expand and cover the inner wall exposed in the valve hole 13 and / or the plate surface of the cover plate 11 located outside the valve hole 13.

[0089] The operating mechanism of implementation scheme (3) is as follows: when the battery cell 300 thermally runs away and its internal pressure is too high, causing the explosion-proof valve 14 to open, the composite explosion-proof valve 14 composed of the insulating fireproof layer 142 and the valve plate 141 ruptures, and the fireproof cracks 1421 formed by the insulating fireproof layer 142 cover the metal cracks formed by the valve plate 141 and expand radially outward. The composite cracks formed by the two will cover the exposed inner wall of the valve hole 13 and / or the plate surface of the cover plate 11 located outside the valve hole 13, thereby reducing or even avoiding the friction between the active substances discharged from the battery cell 300 and the metal parts at the valve hole 13 to catch fire, thereby slowing down the thermal runaway of the battery cell 300. Fig.16 For the composite explosion-proof valve, the fireproof split 1421 formed by the insulating fireproof layer 142 expands outward. On the one hand, the fireproof split 1421 covers and blocks the split 1411 formed by the valve plate 141 from contacting the discharged active substances. On the other hand, after the fireproof split 1421 is fully expanded outward, it will also cover at least part of the plate surface of the cover plate 11 located outside the valve hole 13.

[0090] It should be noted that the battery cover 100 involved in the present invention, in addition to the cover 11, the insulating pad 12 and the explosion-proof valve 14, further includes a negative electrode column 15, a positive electrode column 16 and a liquid injection hole 17, which are respectively arranged through the stacked cover 11 and the insulating pad 12.

[0091] The battery mentioned in the embodiment of the utility model comprises a bare battery cell and an insulating diaphragm covering the outside of the bare battery cell, a negative electrode ear and a positive electrode ear are arranged on the top of the bare battery cell, and the battery cover is electrically connected to the negative electrode ear and the positive electrode ear of the battery cell through the negative electrode column and the positive electrode column respectively.

[0092] The types of batteries involved in the embodiments of the present invention include, but are not limited to, lithium-ion batteries, sodium-ion batteries, and the like.

[0093] On the other hand, an embodiment of the present invention further provides a battery pack, which includes a plurality of batteries as described above, and the plurality of batteries are connected in series or in parallel.

[0094] The battery pack provided by the embodiment of the utility model has all the advantages of the battery provided by the embodiment of the utility model.

[0095] On the other hand, an embodiment of the utility model further provides an energy storage system, which includes a power converter and at least one battery pack as described above; the power converter is used to convert the voltage output by the battery pack into power and output it to a power grid or a load, and / or, convert the voltage output by an external power supply into power and output it to the battery pack.

[0096] The energy storage system provided by the embodiment of the utility model has all the advantages of the battery or battery pack provided by the embodiment of the utility model.

[0097] The above description is only for the purpose of facilitating the technical solution of the present invention to be understood by those skilled in the art, and is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A battery, characterized in that: The battery comprises: a battery cover plate (100), a battery shell (200) and a battery cell (300); the battery cover plate (100) is connected to the battery shell (200) and cooperates to form a closed cavity to accommodate the battery cell (300); The battery cover plate (100) comprises: a cover plate (11) and an insulating pad (12) arranged in a stacked manner, a valve hole (13) penetrating the cover plate (11) and the insulating pad (12), and an explosion-proof valve (14) closing the valve hole (13); The explosion-proof valve (14) comprises: a valve plate (141) and an insulating fireproof layer (142) which are sequentially distributed along the axial direction of the valve hole (13), and the insulating fireproof layer (142) is closer to the battery cell (300) than the valve plate (141), and the insulating fireproof layer (142) has a tear line (1420), and the tear line (1420) comprises a plurality of holes arranged at intervals, and the insulating fireproof layer (142) is capable of being broken based on the tear line (1420) and forming a fireproof split (1421) which expands outward in a radial direction.

2. The battery according to claim 1, characterized in that The valve plate (141) is located in the valve hole (13), and the insulating fireproof layer (142) is located on a surface of the insulating pad (12) facing the battery core (300).

3. The battery according to claim 2, characterized in that The insulating fireproof layer (142) is an insulating fireproof film material with ductility or an insulating fireproof film material with plasticity.

4. The battery according to claim 1, characterized in that The inner wall of the valve hole (13) has an insulating fireproof coating (130), the insulating fireproof layer (142) is located on the surface of the cover plate (11) facing away from the insulating pad (12), and the valve plate (141) is connected to the surface of the cover plate (11) facing away from the insulating pad (12) and covers the insulating fireproof layer (142).

5. The battery according to claim 4, characterized in that The insulating fireproof layer (142) is an insulating fireproof film material with ductility, an insulating fireproof film material with plasticity, or an insulating fireproof coating.

6. The battery according to claim 1, characterized in that The insulating fireproof layer (142) is stacked on the surface of the valve sheet (141) facing the battery core (300) to form a composite explosion-proof valve (14); the composite explosion-proof valve (14) is arranged in the valve hole (13).

7. The battery according to claim 6, characterized in that The insulating fireproof layer (142) is an insulating fireproof film material with ductility, an insulating fireproof film material with plasticity, or an insulating fireproof coating.

8. The battery according to any one of claims 1 to 7, characterized in that: The tear line (1420) is a closed-loop structure. The tear line (1420) separates the insulating fireproof layer (142) into an inner ring portion and an outer ring portion. The area of ​​the inner ring portion is smaller than the area of ​​the valve plate (141).

9. The battery according to claim 8, characterized in that The tear line (1420) may have a circular, elliptical, rectangular or regular polygonal shape.

10. The battery according to any one of claims 1 to 7, characterized in that: The valve plate (141) has a notch (1410), and a projection of the tear line (1420) on the valve plate (141) coincides with the notch (1410).

11. A battery pack, characterized in that: The battery pack comprises a plurality of batteries as described in any one of claims 1 to 10, and the plurality of batteries are connected in series or in parallel.

12. An energy storage system, characterized in that: The energy storage system comprises a power converter and at least one battery pack as claimed in claim 11; The power converter is used to convert the voltage output by the battery pack into power and output it to a power grid or a load, and / or to convert the voltage output by an external power source into power and output it to the battery pack.

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