Battery top cover structure and battery

Abstract

The utility model relates to the technical field of power batteries, and particularly discloses a battery top cover structure and a battery. Wherein the battery top cover structure covers an opening of the battery shell, and a pole group is arranged in the battery shell. Specifically, the battery top cover structure comprises a cover plate, a plastic end plate and a support frame, the cover plate is provided with an anti-explosion valve; one side face of the plastic end plate is attached to the cover plate, and the plastic end plate is provided with a limiting cavity. And the support frame is made of a high-temperature-resistant and electrolyte-resistant material, is fixed in the limiting cavity, and is suitable for being propped between the cover plate and the pole group under the condition that the plastic end plate is melted due to thermal runaway of the battery, so that an exhaust channel communicated with the ventilation opening of the explosion-proof valve is formed between the cover plate and the pole group. According to the scheme, the pole group is prevented from blocking the explosion-proof valve under the impact extrusion of airflow, adverse consequences caused by thermal runaway of the battery are relieved, and the safety performance of the battery is improved. In addition, the battery comprises the battery top cover structure, so that the battery has all the beneficial effects of the battery top cover structure.

Description

Technical Field

[0001] The utility model relates to the technical field of power batteries, in particular to a battery top cover structure and a battery. Background Art

[0002] At present, with the increasing maturity of lithium-ion battery technology, lithium-ion batteries have been widely used as power batteries in the field of electric vehicles. Therefore, people's requirements for the safety performance of lithium-ion batteries are increasing.

[0003] In the traditional lithium-ion battery structure, the cover plate and the shell are welded to encapsulate the electrode group inside the shell; the plastic end plate of the cover plate is against the electrode group, which plays the role of limiting the electrode group. However, when the battery has thermal runaway, the internal temperature of the battery increases, and the gas generation increases, causing the explosion-proof valve to automatically open for exhaust; at this time, the plastic end plate may melt at high temperature, thereby losing the limiting effect on the electrode group, and the electrode group may block the explosion-proof valve under the impact of the airflow, aggravating the battery runaway and posing a greater safety risk. Utility Model Content

[0004] In view of this, the utility model provides a battery top cover structure and a battery to solve the existing problem that when thermal runaway occurs in the battery, the pole group may block the explosion-proof valve under the impact of airflow, aggravating the battery runaway and posing a greater safety risk.

[0005] In the first aspect, the utility model provides a battery top cover structure, which is covered on the opening of the battery shell; the battery shell is provided with a pole group. Specifically, the battery top cover structure includes a cover plate, a plastic end plate and a support frame; wherein the cover plate is provided with an explosion-proof valve; one side of the plastic end plate is fitted with the cover plate, and the plastic end plate is provided with a limiting cavity; the support frame is made of a material resistant to high temperature and electrolyte, and is fixed in the limiting cavity, and the support frame is suitable for abutting between the cover plate and the pole group when the plastic end plate melts due to thermal runaway of the battery, so that an exhaust channel connected to the air vent of the explosion-proof valve is formed between the cover plate and the pole group.

[0006] In an optional embodiment, the exhaust passage has a plurality of guide openings, and the sum of the areas of the plurality of guide openings is greater than or equal to the area of ​​the air vent of the explosion-proof valve.

[0007] In an optional implementation, the air vent of the explosion-proof valve is a waist-shaped hole, and the length of the support frame is greater than the width of the air vent of the explosion-proof valve.

[0008] In an optional implementation, there is a gap between the bottom wall of the limiting cavity and the top surface of the pole group.

[0009] In an optional embodiment, the opening of the limiting cavity is located on the side facing the cover plate; the support frame includes a base plate and folding plates respectively arranged at both ends of the base plate, the base plate is fitted with the bottom surface of the limiting cavity, the folding plate is connected to the bottom plate at a folded angle, and the folding plate extends toward the opening of the limiting cavity; one of the folding plate and the side wall of the limiting cavity is provided with a latch tongue, and the other is provided with a slot, and the latch tongue is engaged with the slot.

[0010] In an optional embodiment, the width of the folding plate is not less than 5 mm.

[0011] In an optional embodiment, the height of the folding plate is smaller than the depth of the limiting cavity.

[0012] In an optional embodiment, the plastic end plate is provided with a plurality of limiting cavities, and the support frames are provided in a plurality, and the plurality of support frames are arranged in the plurality of limiting cavities in a one-to-one correspondence.

[0013] In an optional embodiment, pole ears are respectively provided at both ends of the top surface of the pole group in the length direction, and limiting cavities located outside the pole ears are respectively provided at both ends of the plastic end plate.

[0014] In a second aspect, the utility model further provides a battery, comprising a battery housing, a pole group disposed inside the battery housing, and the battery top cover structure in the first aspect, wherein the battery top cover structure covers an opening of the battery housing.

[0015] Beneficial effects: In the battery top cover structure of the first aspect, a support frame is added between the cover plate and the plastic end plate. When the plastic end plate melts due to thermal runaway of the battery, the support frame abuts between the cover plate and the pole group, so that an exhaust channel connected to the air vent of the explosion-proof valve is formed between the cover plate and the pole group, preventing the pole group from blocking the explosion-proof valve under the impact of the air flow, alleviating the adverse consequences of thermal runaway of the battery, and increasing the safety performance of the battery. In addition, the battery of the second aspect includes the battery top cover structure of the first aspect, so the battery of the second aspect has all the beneficial effects of the battery top cover structure of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 An exploded view of the battery top cover structure according to an embodiment of the utility model;

[0018] Figure 2 This is a schematic diagram of the structure of the battery according to an embodiment of the utility model;

[0019] Figure 3 for Figure 2 Cross-sectional view at AA in the middle;

[0020] Figure 4 for Figure 3 The enlarged view of point B in the middle;

[0021] Figure 5 It is a schematic structural diagram of the support frame described in an embodiment of the utility model.

[0022] Description of reference numerals:

[0023] 100. Battery;

[0024] 110. Battery top cover structure; 120. Battery housing; 130. Electrode group;

[0025] 111. cover plate; 112. plastic end plate; 113. support frame;

[0026] 1111, explosion-proof valve; 1112, pole;

[0027] 1121, limiting cavity; 1122, card slot;

[0028] 1131. Bottom plate; 1132. Folding plate; 1133. Tab. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0030] In order to deepen the understanding of the solution of the utility model, it is necessary to elaborate on the technical problems in detail in combination with relevant technologies. The specific contents are as follows:

[0031] In the traditional lithium-ion battery structure, the cover plate and the shell are welded to encapsulate the electrode group inside the shell; the plastic end plate of the cover plate is against the electrode group, which plays the role of limiting the electrode group. However, when the battery has thermal runaway, the internal temperature of the battery increases, and the gas generation increases, causing the explosion-proof valve to automatically open for exhaust; at this time, the plastic end plate may melt at high temperature, thereby losing the limiting effect on the electrode group, and the electrode group may block the explosion-proof valve under the impact of the airflow, aggravating the battery runaway and posing a greater safety risk.

[0032] Furthermore, batteries generally control their temperature through a dedicated temperature control circuit. When the temperature control circuit fails, the battery may suffer thermal runaway, intensifying the chemical reaction inside the battery and generating more gas. If the high temperature melts the plastic end plate at this time and the electrode group blocks the vent of the explosion-proof valve, the battery is in danger of exploding.

[0033] In order to alleviate the above technical problems, the utility model provides a battery top cover structure and a battery. Figures 1 to 5 The embodiments of the present utility model are described in detail.

[0034] First, refer to Figures 1 to 4 The utility model provides a battery top cover structure 110, which is covered on the opening of the battery housing 120. The battery housing 120 is provided with a pole group 130. The battery top cover structure 110 includes a cover plate 111, a plastic end plate 112 and a support frame 113. The cover plate 111 is provided with an explosion-proof valve 1111; one side of the plastic end plate 112 is in contact with the cover plate 111, and the plastic end plate 112 is provided with a limiting cavity 1121; the support frame 113 is made of a material resistant to high temperature and electrolyte, and is provided in the limiting cavity 1121. The support frame 113 is suitable for abutting between the cover plate 111 and the pole group 130 when the plastic end plate 112 melts due to thermal runaway of the battery 100, so that an exhaust channel connected to the air vent of the explosion-proof valve 1111 is formed between the cover plate 111 and the pole group 130.

[0035] Specifically, a support frame 113 is added between the cover plate 111 and the plastic end plate 112. When the plastic end plate 112 melts due to thermal runaway of the battery 100, the support frame 113 abuts between the cover plate 111 and the electrode group 130, so that an exhaust channel connected to the air vent of the explosion-proof valve 1111 is formed between the cover plate 111 and the electrode group 130, thereby preventing the electrode group 130 from clogging the explosion-proof valve 1111 under the impact of air flow, alleviating the adverse consequences brought about by thermal runaway of the battery 100, and increasing the safety performance of the battery 100.

[0036] More specifically, the surfaces of the plastic end plate 112 and the cover plate 111 fit together, and the plastic end plate 112 is provided with a limiting cavity 1121, which is recessed in a direction away from the cover plate 111, and the support frame 113 is received in the limiting cavity 1121 of the plastic end plate 112, thereby reducing the additional space occupied by the support frame 113 inside the battery housing 120 and having little impact on the overall volume of the battery 100; moreover, the limiting cavity 1121 wraps and limits the support frame 113 to prevent the support frame 113 from moving inside the battery housing 120 and damaging the electrode group 130.

[0037] Furthermore, the plastic end plate 112 is a soft material, and when the battery 100 is subjected to external impact, the plastic end plate 112 will deform; the support frame 113 is arranged in the limiting cavity 1121 of the plastic end plate 112, which can increase the strength of the plastic end plate 112 to reduce the deformation of the plastic end plate 112.

[0038] In particular, the plastic end plate 112 is preferably made of PP (Polypropylene) material with a melting temperature of 160°C.

[0039] In some embodiments, reference Figure 1 The exhaust passage has a plurality of guide ports, and the sum of the areas of the plurality of guide ports is greater than or equal to the area of ​​the air vent of the explosion-proof valve 1111.

[0040] Specifically, in this solution, the sum of the areas of the multiple guide ports is greater than or equal to the area of ​​the air vent of the explosion-proof valve 1111, so that the exhaust rate is not affected and the exhaust can be normal.

[0041] More specifically, after the plastic end plate 112 melts due to thermal runaway of the battery 100, the support frame 113 is supported between the cover plate 111 and the electrode group 130 to form an exhaust channel; the gas generated inside the battery casing 120 enters the exhaust channel from the guide port, and the gas flow directions at different guide ports are different, but all converge at the explosion-proof valve 1111, and then are discharged from the battery casing 120 from the explosion-proof valve 1111.

[0042] Preferably, the exhaust channel extends along the length direction of the cover plate 111, the middle part of the exhaust channel is connected to the air vent when the explosion-proof valve 1111 is opened, and the two ends of the exhaust channel in the length direction are the main guide ports, so the guide port area mainly depends on the height of the support frame 113.

[0043] More preferably, the height of the support frame 113 is greater than or equal to 3 mm.

[0044] In some embodiments, reference Figure 1 The air vent of the explosion-proof valve 1111 is a waist-shaped hole, and the length of the support frame 113 is greater than the width of the air vent of the explosion-proof valve 1111.

[0045] Specifically, the air vent of the explosion-proof valve 1111 is a waist-shaped hole, and the length of the support frame 113 is greater than the width of the air vent of the explosion-proof valve 1111, to prevent the support frame 113 from being flushed out of the explosion-proof valve 1111 by the airflow inside the battery housing 120 after the plastic end plate 112 melts due to thermal runaway of the battery 100.

[0046] In particular, the air vent of the explosion-proof valve 1111 may also be a circular hole, an elliptical hole, or an irregularly shaped opening, and no restriction is imposed on the shape of the air vent; the length of the support frame 113 is greater than the maximum inner diameter of the air vent of the explosion-proof valve 1111, that is, the length of the longest line segment connecting the inner edges of the air vent is less than the length of the support frame 113. The above embodiments are all within the protection scope of this patent.

[0047] In some embodiments, reference Figure 3 and Figure 4 There is a gap between the bottom wall of the limiting cavity 1121 and the top surface of the electrode group 130.

[0048] Specifically, a gap is formed between the side of the limiting cavity 1121 close to the electrode group 130 and the electrode group 130 to prevent the electrode group 130 from being crushed.

[0049] In particular, the plastic end plate 112 is made of soft material, and the side wall of the limiting cavity 1121 close to the pole group 130 slightly presses the pole group 130, while ensuring that the compression deformation of the limiting cavity 1121 is not greater than 2 mm, that is, there is no gap between the side of the limiting cavity 1121 close to the pole group 130 and the pole group 130. This solution can also prevent the pole group 130 from being crushed, and is also within the protection scope of this patent.

[0050] It should be noted that the distance between the other parts of the plastic end plate 112 excluding the limiting cavity 1121 and the electrode group 130 is the same as above, that is, a gap can be maintained between the plastic end plate 112 and the electrode group 130 , or the plastic end plate 112 can slightly press the electrode group 130 .

[0051] In some embodiments, reference Figure 1 and Figure 5 , focus on Figure 5 The opening of the limiting cavity 1121 is located on the side facing the cover plate 111; the support frame 113 includes a bottom plate 1131 and folding plates 1132 respectively arranged at both ends of the bottom plate 1131, the bottom plate 1131 is in contact with the bottom surface of the limiting cavity 1121, the folding plate 1132 is connected to the bottom plate 1131 at an angle, and the folding plate 1132 extends toward the opening of the limiting cavity 1121; one of the folding plate 1132 and the side wall of the limiting cavity 1121 is provided with a latch 1133, and the other is provided with a slot 1122, and the latch 1133 is engaged with the slot 1122.

[0052] Specifically, this solution is a specific implementation of the limiting cavity 1121 and the support frame 113. The limiting cavity 1121 and the support frame 113 are fixed by snapping, which is easy to operate and has a tight connection.

[0053] More specifically, the limiting cavity 1121 extends along the width direction of the plastic end plate 112, and the side walls at both ends of the limiting cavity 1121 are provided with a slot 1122. The folding plate 1132 is provided with a tongue 1133. The tongue 1133 is stamped from the folding plate 1132, and the tongue 1133 protrudes outward, and the bottom edge is connected to the folding plate 1132, and the remaining parts are separated from the folding plate 1132; the bottom of the tongue 1133 has an inclined surface inclined inwardly, and the top of the tongue 1133 is bent with a tendency to return to its original shape upward. When placing the support frame 113 into the limiting cavity 1121, the side wall of the limiting cavity 1121 presses the latch 1133, causing it to have elastic potential energy protruding outward, until the bottom plate 1131 fits against the bottom wall of the limiting cavity 1121, and the latch 1133 is just inserted into the slot 1122; at this time, the top edge of the latch 1133 abuts against the top wall of the slot 1122, or a gap of no more than 0.5 mm is left to limit the height direction of the support frame 113; the width of the latch 1133 is not less than 2 mm to ensure a certain degree of elasticity; the width of the slot 1122 is greater than the latch 1133, and the bottom wall of the slot 1122 is lower than the bottom edge of the latch 1133, so that the latch 1133 can be easily inserted into the slot 1122.

[0054] Furthermore, the folding plate 1132 is the same width as the bottom plate 1131 and is integrally formed, and the bending angle between the folding plate 1132 and the bottom plate 1131 can be 90°±15°, preferably 90°; the width and length of the limiting cavity 1121 are slightly larger than the width and length of the bottom plate 1131, so as to facilitate placing the support frame 113 into the limiting cavity 1121; however, the dimensional difference between the length and width of the limiting cavity 1121 and the length and width of the support frame 113 is within 0.5 mm, so as to prevent the support frame 113 from shaking in the limiting cavity 1121.

[0055] In particular, the support frame 113 is preferably made of metal, for example, aluminum, copper, stainless steel, etc., which can meet the requirements of electrolyte resistance and high temperature resistance; because aluminum is relatively soft, in order for the support frame 113 to be able to resist impact and not deform when the battery 100 is thermally runaway, when the support frame 113 is made of aluminum, the thickness must be not less than 0.5mm; if the support frame 113 is made of copper, the thickness must be not less than 0.3mm; when the support frame 113 is made of stainless steel, the thickness must be not less than 0.2mm. In addition, when the support frame 113 is made of copper, try not to place it on the negative side of the battery 100 to avoid the negative electrode potential being low due to a micro-short circuit of the battery 100, and the lithium ions being embedded in the aluminum causing corrosion, which will destroy the mechanical properties of the support frame 113 that plays a supporting role.

[0056] In some embodiments, reference Figure 5 , the width of the folding plate 1132 is not less than 5 mm.

[0057] Specifically, the width of the folding plate 1132 is not less than 5 mm, which ensures the strength of the support frame 113 and can leave enough material for stamping the tongue 1133 .

[0058] Furthermore, the folding plate 1132 is relatively wide, that is, the support frame 113 is relatively wide and has a certain strength, thereby ensuring that the support frame 113 will not be plastically deformed under the impact of the pole group 130 .

[0059] In some embodiments, reference Figure 4 , the height of the folding plate 1132 is less than the depth of the limiting cavity 1121.

[0060] Specifically, the height of the folding plate 1132 is less than the depth of the limiting cavity 1121, and there is a gap between the top of the folding plate 1132 and the cover plate 111. The cover plate 111 is preferably an aluminum plate to prevent the folding plate 1132 from contacting and colliding with the cover plate 111, causing metal chips to fall into the battery housing 120 and cause a micro short circuit.

[0061] In some embodiments, reference Figure 1 The plastic end plate 112 is provided with a plurality of limiting cavities 1121 , and the supporting frames 113 have a plurality of supporting frames 113 , which are arranged in the plurality of limiting cavities 1121 in a one-to-one correspondence.

[0062] Specifically, this solution can make the flow cross-section of the exhaust passage uniform after the battery 100 thermally runs away, and further increase the overall structural strength.

[0063] More specifically, the limiting cavity 1121 and the support frame 113 do not affect the structural design of other components of the battery 100 .

[0064] In some embodiments, reference Figure 1 and Figure 3 The top surface of the electrode group 130 is provided with electrode ears at both ends in the length direction, and the two ends of the plastic end plate 112 are provided with limiting cavities 1121 located outside the electrode ears.

[0065] Specifically, after the plastic end plate 112 melts due to thermal runaway of the battery 100 , the tabs have a blocking effect on the support frame 113 , preventing the support frame 113 from being impacted by airflow and moving.

[0066] More specifically, poles 1112 are provided at both ends of the cover plate 111 , and the poles 1112 correspond to the pole ears and are electrically connected.

[0067] Secondly, refer to Figure 2 and Figure 3 The utility model further provides a battery 100 , including a battery housing 120 , a pole group 130 disposed inside the battery housing 120 , and a battery top cover structure 110 , wherein the battery top cover structure 110 covers an opening of the battery housing 120 .

[0068] Specifically, the battery 100 in this solution includes a battery top cover structure 110, so the battery 100 has all the beneficial effects of the battery top cover structure 110. In addition, the battery 100 in this solution also includes other components such as a battery protection plate, and only the components related to this solution are listed here, but the composition of the battery 100 is not limited.

[0069] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery top cover structure, covering the opening of a battery housing, wherein a pole group is arranged inside the battery housing, characterized in that: The battery top cover structure comprises: A cover plate, wherein the cover plate is provided with an explosion-proof valve; A plastic end plate, one side of which is in contact with the cover plate, and the plastic end plate is provided with a limiting cavity; The support frame is made of a material resistant to high temperature and electrolyte, and is fixed in the limiting cavity. The support frame is suitable for abutting between the cover plate and the pole group when the plastic end plate melts due to thermal runaway of the battery, so that an exhaust channel connected to the air vent of the explosion-proof valve is formed between the cover plate and the pole group.

2. The battery top cover structure according to claim 1, characterized in that: The exhaust passage has a plurality of guide ports, and the sum of the areas of the plurality of guide ports is greater than or equal to the area of ​​the air vent of the explosion-proof valve.

3. The battery top cover structure according to claim 1, characterized in that: The air vent of the explosion-proof valve is a waist-shaped hole, and the length of the support frame is greater than the width of the air vent of the explosion-proof valve.

4. The battery top cover structure according to claim 1, characterized in that: There is a gap between the bottom wall of the limiting cavity and the top surface of the pole group.

5. The battery top cover structure according to claim 1, characterized in that: The opening of the limiting cavity is located on a side facing the cover plate; The support frame includes a bottom plate and folding plates respectively arranged at both ends of the bottom plate, the bottom plate is in contact with the bottom surface of the limiting cavity, the folding plates are connected to the bottom plate at a folded angle, and the folding plates extend toward the opening of the limiting cavity; One of the folding plate and the side wall of the limiting cavity is provided with a latch tongue, and the other is provided with a latch groove, and the latch tongue is engaged with the latch groove.

6. The battery top cover structure according to claim 5, characterized in that: The width of the folding plate is not less than 5 mm.

7. The battery top cover structure according to claim 5, characterized in that: The height of the folding plate is smaller than the depth of the limiting cavity.

8. The battery top cover structure according to any one of claims 1 to 6, characterized in that: The plastic end plate is provided with a plurality of limiting cavities, and the support frames are provided in a plurality of positions. The plurality of support frames are arranged in a one-to-one correspondence in the plurality of limiting cavities.

9. The battery top cover structure according to claim 8, characterized in that: The top surface of the pole group is provided with pole ears at both ends in the length direction, and the two ends of the plastic end plate are provided with the limiting cavity located outside the pole ears.

10. A battery, characterized in that: The invention comprises a battery casing, a pole group arranged inside the battery casing, and a battery top cover structure according to any one of claims 1 to 9, wherein the battery top cover structure covers an opening of the battery casing.

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