CN117497966A - Battery and battery pack - Google Patents

Abstract

The invention relates to the technical field of battery devices, and discloses a battery and a battery pack. The battery includes: a cover assembly, which is integrated with poles and explosion-proof valves suitable for communicating with external circuits; and a pole group, which is arranged facing the cover assembly. The top surface of the pole assembly has pole tabs formed on the top surface of the pole assembly; the plane where the pole tabs are located and the top surface of the pole assembly are set at an angle A, where 0°＜A≤90°; the conductive connecting piece is connected to the pole post and the pole Between the ears, the conductive connecting piece has a pole connection part parallel to the top surface of the pole group, and a pole connection part arranged at an angle B with the pole connection part, where 0°<B≤90°; the pole connection part It is electrically connected to the pole, and the pole connection part is electrically connected to the pole; the pole connection part is supported between the cover assembly and the pole assembly, so that the cover assembly and the top surface of the pole assembly form a connection with the explosion-proof valve. Exhaust cavity; the melting point of the conductive connecting piece is higher than the exhaust temperature of the battery in a thermal runaway state. Ensure the continuity between the exhaust cavity and the explosion-proof valve.

Description

Batteries and battery packs

Technical field

The present invention relates to the technical field of battery devices, and in particular to a battery and a battery pack.

Background technique

As battery technology becomes increasingly mature, battery safety requirements are increasing. In traditional rectangular batteries, the cover plate and the shell are welded and sealed to encapsulate the electrode group inside. The electrode group and the cover plate pole are connected through the connecting piece. The lower plastic in the cover plate can resist the electrode group and play a role. Pole group limiting function.

However, when the battery thermally runs out of control, the temperature inside the battery is too high and the gas produced inside the battery is too high. When the triggering condition is reached, the explosion-proof valve opens and the gas produced inside the battery is rapidly discharged. However, during the exhaust process, there is a risk that the electrode assembly will be pushed upward by the airflow. At this time, due to the battery being out of control and the temperature being too high, the lower plastic made of PP material will completely melt at high temperatures, and the electrode assembly will lose its limit. If the pole group is lifted up by the airflow, there is a risk of blocking the explosion-proof valve, accelerating the battery out of control, and posing a major safety hazard.

Contents of the invention

In view of this, the present invention provides a battery and a battery pack to solve the problem that the limiting structure of the electrode group melts during thermal runaway, which easily causes the electrode group to be lifted up by the air flow and block the explosion-proof valve.

In a first aspect, the present invention provides a battery, including:

Cover assembly, integrated with poles and explosion-proof valves suitable for communication with external circuits;

The pole assembly has a top surface of the pole assembly facing the cover assembly, and pole ears are formed on the top surface of the pole assembly; the plane where the pole tabs are located is set at an angle A with the top surface of the pole assembly, where 0°<A≤90°;

The conductive connection piece is connected between the pole and the pole tab. The conductive connection piece has a pole connection part parallel to the top surface of the pole group, and a pole connection part arranged at an angle B with the pole connection part, where 0° <B≤90°; the pole connection part is electrically connected to the pole, and the pole tab connection part is electrically connected to the pole tab;

The pole tab connection part is supported between the cover plate assembly and the pole assembly, so that an exhaust cavity connected to the explosion-proof valve is formed between the cover plate assembly and the top surface of the pole assembly;

The melting point of the conductive connecting piece is higher than the exhaust temperature of the battery in a thermal runaway state.

Beneficial effects: The battery provided by the present invention is provided with a conductive connecting piece, and the conductive connecting piece is formed with a tab connecting portion, and the tab connecting portion is supported between the cover plate assembly and the pole group, so that the cover plate assembly and the pole group are connected. It forms an exhaust cavity connected with the explosion-proof valve; thus it can play a supporting role to ensure the connection between the exhaust cavity and the explosion-proof valve, reduce the risk of the explosion-proof valve being blocked, and improve the safety of the battery when thermal runaway. The conductive connecting piece is connected between the pole and the pole lug by providing a conductive connecting piece. The conductive connecting piece has a pole connecting part parallel to the top surface of the pole group, and a pole tab connecting part arranged at an angle B with the pole connecting part, where, 0 °<B≤90°, and the tab connecting portion is electrically connected to the tab, so that the tab connecting portion is supported between the cover assembly and the pole assembly, so that an explosion-proof connection is formed between the cover assembly and the top surface of the pole assembly. The exhaust cavity is connected with the valve; at the same time, the tab electrically connected to the tab connection part can be set at an angle A with the top surface of the pole group, where 0°<A≤90° can ensure that the tab is in a more natural position. shape, reducing bending operations and avoiding undesirable situations such as damage to the tabs.

In an optional implementation, the minimum distance between the surface of the explosion-proof valve facing the top surface of the pole group and the top surface of the pole group is H, where H satisfies H ≥ 3 mm.

Beneficial effect: By limiting the minimum distance between the surface of the explosion-proof valve facing the top surface of the pole group and the top surface of the pole group to H, where H satisfies H ≥ 3 mm, the pole lug connection part can play a role in supporting the exhaust space. The function of the cavity is to avoid blocking the explosion-proof valve, and at the same time, it can prevent the pole group from contacting the connecting piece causing short circuit or scratching.

In an optional implementation, the pole tab connecting portion is folded toward one side of the pole group.

Beneficial effect: By folding the tab connection part toward the side of the pole assembly, the tab connection part can be in contact with each other and at the same time, it is convenient to weld the pole connection part and the pole without setting up an additional welding structure. Simplify the structural form of the conductive connecting piece.

In an optional embodiment, the plane where the pole connection part is located is perpendicular to the plane where the pole tab connection part is located; and the plane where the pole tab is located is perpendicular to the top surface of the pole group.

Beneficial effect: By making the plane where the pole connection part is located perpendicular to the plane where the pole connection part is located, and the plane where the pole connection is perpendicular to the top surface of the pole group, it can further ensure that the plane where the pole tab is located and the top surface of the pole group are set at right angles, reducing the number of The length of the pole lug, there is no need to fold the pole lug. This reduces the length of the pole tab, reduces the cost, and reduces the overall width of the pole piece, thereby saving more material on the pole piece copper and aluminum foil, and making it easier for equipment to cut. This allows the tabs to maintain a more natural shape, reduce bending operations, and avoid damage.

In an optional embodiment, along the thickness direction perpendicular to the battery, the tab includes a first tab portion and a second tab portion that are spaced apart;

The pole connection part is provided with pole connection parts on both sides along the thickness direction perpendicular to the battery;

The tab connecting portions on both sides are arranged in close contact with the first tab portion and the second tab portion respectively, and the conductive connecting piece is arranged in the area between the first tab portion and the second tab portion.

Beneficial effect: By arranging the pole connection portion with tab connection portions on both sides along the thickness direction perpendicular to the battery, the tab connection portions on both sides are respectively in contact with the first tab portion and the second tab portion. Specifically, the tab connection part is arranged inside the first tab part and the second tab part, so as to facilitate the fitting of the tab and the tab connection part and facilitate the welding operation.

In an optional embodiment, the conductive connecting piece further includes a bent portion, the bent portion extends from an end of the tab connecting portion away from the pole connecting portion, and the bent portion is turned toward the side closer to the tab. fold;

The folding angle of the plane where the bent part is located relative to the plane where the tab connecting part is located is B, where B ≥ 30°.

Beneficial effect: By extending the bending portion at one end of the pole connection portion away from the pole connection portion, and folding the bending portion toward the side closer to the pole tab, the conductive connecting piece and the pole tab can be assembled. Avoid scratches between the pole connection and the tabs to avoid damage to the tabs.

In an optional embodiment, the pole connection part, the pole connection part and the bending part are integrally formed.

In an optional embodiment, the conductive connecting piece includes a positive connecting piece and a negative connecting piece, the positive connecting piece is suitable for connecting with the positive pole, and the negative connecting piece is suitable for connecting with the negative pole;

The material of the positive electrode connecting piece includes aluminum, and the material of the negative electrode connecting piece includes copper.

In an optional embodiment, the thickness of the positive electrode connecting piece is not less than 0.5 mm, and the thickness of the negative electrode connecting piece is not less than 0.3 mm.

In a second aspect, the present invention also provides a battery pack, including: the battery as described above.

Because the battery pack includes a battery and has the same effect as the battery, it will not be described again here.

Description of drawings

In order to more clearly explain the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings that need to be used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description The drawings illustrate some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting any creative effort.

Figure 1 is an exploded schematic diagram of the battery of the present invention;

Figure 2 is a schematic cross-sectional view of the battery of the present invention;

Figure 3 is an enlarged view of point A in Figure 2;

Figure 4 is a partial enlarged view of Figure 1.

Explanation of reference symbols:

1. Housing; 2. Pole group; 21. Poles; 211. First pole tab; 212. Second pole tab; 22. Top surface of pole group; 3. Conductive connecting piece; 31. Pole connection part ; 32. The pole connection part; 33. The bending part; 4. The cover assembly; 41. The positive pole; 42. The negative pole; 43. The explosion-proof valve.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate The orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation or be constructed in a specific orientation. and operation, and therefore cannot be construed as limitations of the present invention. Furthermore, the terms “first”, “second” and “third” are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. Connection, or integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

The following describes embodiments of the present invention with reference to FIGS. 1 to 4 .

According to an embodiment of the present invention, in one aspect, a battery is provided, including:

The cover assembly 4 is integrated with a pole suitable for communicating with external circuits and an explosion-proof valve 43;

The pole assembly 2 has a top surface 22 of the pole assembly facing the cover assembly 4. A pole lug 21 is formed on the top surface 22 of the pole assembly; the plane where the pole lug 21 is located is arranged at an angle A with the top surface 22 of the pole assembly, where, 0 °＜A≤90°;

The conductive connecting piece 3 is connected between the pole and the pole lug 21. The conductive connecting piece 3 has a pole connecting part 31 parallel to the pole assembly top surface 22, and a pole lug arranged at an angle B with the pole connecting part 31. The connection part 32, where 0°<B≤90°; the pole connection part 31 is electrically connected to the pole, and the pole connection part 32 is electrically connected to the pole 21;

The pole connection part 32 is supported between the cover assembly 4 and the pole assembly 2, so that an exhaust cavity connected to the explosion-proof valve 43 is formed between the cover assembly 4 and the pole assembly top surface 22;

The melting point of the conductive connecting piece 3 is higher than the exhaust temperature of the battery in a thermal runaway state.

The battery includes a casing 1. The casing 1 is formed with an opening. A pole assembly 2 is provided in the casing 1. A cover assembly 4 is installed at the opening of the casing 1 and is sealedly connected to the casing 1 through the cover assembly 4. The pole assembly 2 can be sealed inside the housing 1 .

In order to realize the conduction between the pole group 2 and the external circuit, the cover assembly 4 is integrated with poles suitable for conduction with the external circuit, and the poles and the tabs 21 are connected through the conductive connecting pieces 3 .

In this embodiment, a positive electrode tab and a negative electrode tab are formed on the top surface 22 of the electrode assembly. The positive electrode tab is electrically connected to the positive electrode post 41 through the conductive connecting piece 3, and the negative electrode tab is electrically connected to the negative electrode post 42 through the conductive connecting piece 3.

The plane where the pole lug 21 is located is set at an angle A with the top surface 22 of the pole assembly, where 0°＜A≤90°; the pole lug 21 is composed of stacked pole tab parts protruding from multiple pole pieces, and the pole tab 21 is kept after being folded In a vertical state or at an acute angle with the top surface 22 of the pole assembly, it is convenient for butt welding of the tab 21 and the tab connecting portion 32 of the conductive connecting piece 3 . Compared with the traditionally designed pole tabs, the pole tabs 21 of this embodiment do not need to be folded and then welded to the connecting piece, which reduces the length of the pole tabs, reduces the cost, reduces the overall width of the pole pieces, and further reduces the copper content of the pole pieces. , Aluminum foil saves more materials and is more convenient for equipment to cut. This allows the tabs to maintain a more natural shape, reduce bending operations, and avoid damage.

The battery provided by the embodiment of the present invention is provided with a conductive connecting piece 3, and the conductive connecting piece 3 is formed with a tab connecting portion 32. The tab connecting portion 32 is supported between the cover plate assembly 4 and the pole assembly 2, so that the cover An exhaust cavity connected to the explosion-proof valve 43 is formed between the plate assembly 4 and the pole group 2; thus, it can play a supporting role to ensure the connection between the exhaust cavity and the explosion-proof valve 43, and reduce the risk of the explosion-proof valve 43 being blocked. , which improves the safety of the battery in case of thermal runaway.

When the battery is thermally out of control, a large amount of gas will be produced, and the rapidly discharged air flow needs to be discharged from the explosion-proof valve. Since the lower plastic made of PP material will completely melt at high temperatures, it will lose its limiting effect on the electrode group, and the electrode group will have Risk of being pushed upward by air currents. In this embodiment, the conductive connecting piece 3 is provided. Since the melting point of the conductive connecting piece 3 is higher than the exhaust temperature of the battery in a thermal runaway state, it will not be melted, and the tab connecting portion 32 can be supported between the cover assembly 4 and the pole. Between group 2, prevent the risk of blockage of the explosion-proof valve after pole group 2 is jacked up by the air flow, and maintain the exhaust channel of the explosion-proof valve.

The battery provided by the embodiment of the present invention is connected between the pole and the tab 21 by providing a conductive connecting piece 3. The conductive connecting piece 3 has a pole connecting portion 31 parallel to the top surface 22 of the pole group, and is connected to the pole. The connecting portion 31 is a tab connecting portion 32 arranged at an angle B, where 0°<B≤90°, and the tab connecting portion 32 is electrically connected to the tab 21, so that the tab connecting portion 32 is supported on the cover assembly 4 and the pole assembly 2, so that an exhaust cavity connected to the explosion-proof valve 43 is formed between the cover plate assembly 4 and the top surface 22 of the pole assembly; at the same time, the pole tab 21 electrically connected to the pole tab connection part 32 can be connected to the pole assembly 2. The top surface 22 of the pole assembly is set at an angle A, where 0°<A≤90° can ensure that the pole tabs are in a more natural shape, reduce bending operations, and avoid undesirable situations such as pole tab damage.

In some embodiments, the minimum distance between the surface of the explosion-proof valve 43 facing the pole assembly top surface 22 and the pole assembly top surface 22 is H, where H satisfies H ≥ 3 mm.

By providing the conductive connecting piece 3, when the battery is exhausted due to thermal runaway, the tab connecting portion 32 can be supported between the cover assembly 4 and the pole assembly 2 to maintain the surface of the explosion-proof valve 43 facing the top surface 22 of the pole assembly. The minimum spacing between the top surfaces 22 of the pole group.

The tab connecting part 32 is in surface contact with the pole assembly 2. In this embodiment, the pole connecting part 31 is arranged parallel to the top surface 22 of the pole set, and the tab connecting part 32 is perpendicular to the pole connecting part 31, so that The plane where the tab connecting portion 32 is located is perpendicular to the top surface 22 of the pole assembly.

In addition, the plane where the tab connecting part 32 is located can also be arranged at an acute or obtuse angle with the plane where the pole connecting part 31 is located. At this time, in order to ensure that the surface where the tab connecting part 32 contacts the pole group 2 is still a plane, it can be The end of the tab connecting portion 32 away from the pole connecting portion 31 is further bent to ensure that the bent area is in surface contact with the top surface 22 of the pole assembly. Avoid excessive pressure caused by line contact or point contact, and avoid damaging the pole pieces that make up pole group 2.

By limiting the minimum distance between the surface of the explosion-proof valve 43 facing the pole assembly top surface 22 and the pole assembly top surface 22 to H, where H satisfies H≥3mm, the pole tab connection portion 32 can support the exhaust gas. The function of the cavity prevents the explosion-proof valve from being blocked, and at the same time prevents the pole assembly from contacting the connecting piece causing short circuit or scratches.

Define the exhaust area of the explosion-proof valve as S1; define the minimum exhaust cross-sectional area of the exhaust cavity along the length direction perpendicular to the cover assembly 4 as S2; in order to ensure smooth exhaust, it is necessary to define S2>S1.

In this embodiment, the size of the minimum distance H between the first plane and the second plane can be deduced inversely based on the minimum exhaust cross-sectional area S2 of the exhaust cavity.

In some embodiments, as shown in FIG. 4 , the tab connecting portion 32 is folded toward the side of the pole assembly 2 .

By folding the tab connecting portion 32 toward the pole assembly 2 side, the end of the tab connecting portion 32 can be brought into contact with the surface of the pole assembly 2, so that an explosion-proof connection is formed between the cover assembly 4 and the pole assembly 2. The exhaust cavity connected with the valve 43; and when the pole assembly 2 is pushed out by the air flow toward the explosion-proof valve 43, the pole tab connecting portion 32 can be pressed against the pole assembly 2 to prevent the pole assembly 2 from moving, thereby ensuring the exhaust The air cavity has enough space.

By folding the tab connecting portion 32 toward the pole assembly 2 side, the tab connecting portion 32 can not only play a contact role, but also facilitate the welding of the tab connecting portion 32 and the tab 21 without the need for additional welding. structure, simplifying the structural form of the conductive connecting piece 3.

In some embodiments, as shown in FIG. 4 , the plane where the pole connecting part 31 is located is perpendicular to the plane where the pole tab connecting part 32 is located; and the plane where the pole tab 21 is located is perpendicular to the top surface 22 of the pole group.

By making the plane where the pole connecting part 31 is perpendicular to the plane where the pole lug connecting part 32 is located, and the plane where the pole lug 21 is perpendicular to the top surface 22 of the pole group, it can further ensure that the plane where the pole lug 21 is located is at right angles to the top surface 22 of the pole group. setting, the length of the pole lug is reduced, and there is no need to fold the pole lug 21. This reduces the length of the pole tab, reduces the cost, and reduces the overall width of the pole piece, thereby saving more material on the pole piece copper and aluminum foil, and making it easier for equipment to cut. This allows the tabs to maintain a more natural shape, reduce bending operations, and avoid damage.

In some embodiments, as shown in FIG. 4 , along the thickness direction perpendicular to the battery, the tab 21 includes a first tab portion 211 and a second tab portion 212 that are spaced apart;

The pole connection part 31 is provided with tab connection parts 32 on both sides along the thickness direction perpendicular to the battery;

The tab connecting portions 32 on both sides are respectively arranged to fit the first tab portion 211 and the second tab portion 212 , and the conductive connecting piece 3 is disposed between the first tab portion 211 and the second tab portion 212 . area.

The thickness direction of the battery is the direction in which the pole pieces are stacked. In this embodiment, the first pole tab portion 211 and the second pole tab portion 212 are formed by spacing the pole tabs 21 along the direction perpendicular to the thickness direction of the battery, so as to facilitate Divide the pole tabs from the pole group into two parts to facilitate the pinching of the pole tabs 21. Avoid the pole lug 21 being too thick and inconvenient for processing.

By disposing the tab connecting portions 32 on both sides of the pole connecting portion 31 perpendicular to the thickness direction of the battery, the tab connecting portions 32 on both sides are respectively connected with the first tab portion 211 and the second tab portion. 212, and specifically, the tab connecting part 32 is arranged inside the first tab part 211 and the second tab part 212, thereby facilitating the fitting of the tabs and the tab connecting part 32 and facilitating the welding operation. .

In some embodiments, as shown in FIG. 4 , the conductive connecting piece 3 also includes a bent portion 33 , which extends from one end of the tab connecting portion 32 away from the pole connecting portion 31 , and the bent portion 33 Fold toward the side close to the pole lug 21;

The folding angle of the plane where the bent part 33 is located relative to the plane where the tab connecting part 32 is located is B, where B ≥ 30°.

By extending the bending portion 33 from one end of the tab connecting portion 32 away from the pole connecting portion 31 and folding the bent portion 33 toward the side closer to the tab 21 , the conductive connecting piece 3 can be connected to the tab 21 When assembling, avoid scratches between the pole connection part 31 and the pole tab 21 to prevent the pole tab 21 from being damaged.

The folding angle of the plane where the bent portion 33 is relative to the plane where the tab connecting portion 32 is located is not less than 30°, and the length of the bent portion 33 extending from the tab connecting portion 32 is not less than 1 mm.

In some embodiments, as shown in FIG. 4 , the pole connecting part 31 , the tab connecting part 32 and the bending part 33 are integrally formed.

That is, by using the conductive connecting piece 3 to be integrally stamped, the processing and shaping of the conductive connecting piece 3 can be facilitated, the processing cost can be reduced, and the bending angle of the tab connecting portion 32 can be easily ensured.

In some embodiments, as shown in FIG. 1 , the conductive connecting piece 3 includes a positive connecting piece and a negative connecting piece, the positive connecting piece is suitable for communicating with the positive pole 41 , and the negative connecting piece is suitable for communicating with the negative pole 42 ;

The material of the positive electrode connecting piece includes aluminum, and the material of the negative electrode connecting piece includes copper.

In some embodiments, the thickness of the positive electrode connecting piece is not less than 0.5 mm, and the thickness of the negative electrode connecting piece is not less than 0.3 mm.

Since the material of aluminum is relatively soft, in order to ensure that the positive electrode connecting piece resists the impact of the pole and does not deform when thermal runaway occurs, the thickness of the positive electrode connecting piece is not less than 0.5mm.

Since copper is a relatively hard material, the thickness of the negative electrode connecting piece can be relatively thin. In this embodiment, the thickness of the negative electrode connecting piece is not less than 0.3 mm.

According to an embodiment of the present invention, on the other hand, a battery pack is also provided, including: the above-mentioned battery.

The battery pack provided by the embodiment of the present invention is provided with a conductive connecting piece 3, and the conductive connecting piece 3 is formed with a tab connecting portion 32, and the tab connecting portion 32 is supported between the cover assembly 4 and the pole assembly 2, so that An exhaust cavity connected to the explosion-proof valve 43 is formed between the cover plate assembly 4 and the pole group 2; thus, it can play a supporting role to ensure the connection between the exhaust cavity and the explosion-proof valve 43, and reduce the risk of the explosion-proof valve 43 being blocked. risk and improves the safety of the battery in case of thermal runaway.

Obviously, the above-mentioned embodiments are only examples for clear explanation and are not intended to limit the implementation. Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the limits of the present invention. within the range.

Claims (10)

1. A battery, characterized in that it includes: Cover assembly, integrated with poles and explosion-proof valves suitable for communication with external circuits; The pole assembly has a top surface of the pole assembly facing the cover assembly, and pole tabs are formed on the top surface of the pole assembly; the plane where the pole tabs are located is arranged at an angle A with the top surface of the pole assembly, wherein, 0°＜A≤90°; A conductive connection piece is connected between the pole and the pole lug. The conductive connection piece has a pole connection part parallel to the top surface of the pole group, and is arranged at an angle B with the pole connection part. The pole connection part, wherein 0°<B≤90°; the pole connection part is electrically connected to the pole, and the pole connection part is electrically connected to the pole; The tab connecting portion is supported between the cover plate assembly and the pole assembly, so that an exhaust cavity connected to the explosion-proof valve is formed between the cover plate assembly and the top surface of the pole assembly. ; The melting point of the conductive connecting piece is higher than the exhaust temperature of the battery in a thermal runaway state. 2. The battery according to claim 1, wherein the minimum distance between the surface of the explosion-proof valve facing the top surface of the pole group and the top surface of the pole group is H, where H satisfies H ≥3mm. 3. The battery according to claim 1, wherein the tab connecting portion is folded toward the electrode group side. 4. The battery according to claim 3, wherein the plane of the pole connecting portion is perpendicular to the plane of the tab connecting portion; and the plane of the pole tab is perpendicular to the top surface of the pole group. 5. The battery according to claim 4, wherein along the thickness direction perpendicular to the battery, the tab includes a first tab portion and a second tab portion that are spaced apart; The pole connection portion is provided with the tab connection portion on both sides of the pole connection portion along the thickness direction perpendicular to the battery; The tab connecting portions on both sides are arranged in close contact with the first tab portion and the second tab portion respectively, and the conductive connecting piece is provided on the first tab portion and the second tab portion. The area between the poles. 6. The battery according to claim 5, wherein the conductive connecting piece further includes a bending portion extending from an end of the tab connecting portion away from the pole connecting portion. , and the bent portion is folded toward the side close to the tab; The folding angle of the plane where the bent part is located relative to the plane where the tab connecting part is located is B, where B ≥ 30°. 7. The battery according to claim 6, wherein the pole connection part, the tab connection part and the bending part are integrally formed. 8. The battery according to any one of claims 1 to 7, wherein the conductive connecting piece includes a positive connecting piece and a negative connecting piece, the positive connecting piece is adapted to be connected to the positive pole, and the negative electrode The connecting piece is suitable for connecting with the negative pole; The material of the positive electrode connecting piece includes aluminum, and the material of the negative electrode connecting piece includes copper. 9. The battery according to claim 8, wherein the thickness of the positive electrode connecting piece is not less than 0.5 mm, and the thickness of the negative electrode connecting piece is not less than 0.3 mm. 10. A battery pack, characterized by comprising the battery according to any one of claims 1 to 9.