WO2018090175A1 - Secondary battery and battery module - Google Patents

Abstract

A secondary battery and a battery module, relating to the technical field of energy storage device production. The secondary battery comprises a first terminal (20), a second terminal (30), a top cover sheet (10), an electrode assembly, a connecting member (40) and a turnover sheet (70), wherein the electrode assembly comprises a first pole piece and a second pole piece; at least one of the first terminal (20) and the second terminal (30) and the top cover sheet (10) are arranged in an insulating manner; the connecting member (40) is electrically connected to the second terminal (20); the turnover sheet (70) is attached to the first terminal (20); in a normal state, the first pole piece is electrically connected to the first terminal (20) by means of the turnover sheet (70), and the second terminal (30) is electrically connected to the second pole piece; and when pressure in the secondary battery exceeds a reference pressure, the turnover sheet (70) can turn over so that the turnover sheet (70) disconnects from the electrical connection with the first pole piece, and the turned-over turnover sheet (70) is electrically connected to the connecting member (40) so that the first terminal (20) and the second terminal (30) are electrically connected. As a result, even if a vehicle is in a running state, it will not suddenly stop working, thus improving the safety of the vehicle.

Description

Secondary battery and battery module Technical field

The present application relates to the field of energy storage device production technologies, and in particular, to a secondary battery and a battery module.

Background technique

For the EV hard shell battery, in order to solve the overcharge problem, the commonly adopted scheme in the industry is to cut off the main circuit of the battery before the battery core fails, to prevent the battery from continuing to be charged, so as to ensure the safety of the battery. The common structure is that a current cut-off structure is provided in the main circuit electrically connected to the first terminal and the electrode assembly, and the second terminal is always electrically insulated from the current cut-off structure. When the battery is overcharged, the internal gas is generated, and the internal air pressure is increased to a certain value. When the value is activated, the current cut-off structure is activated to open the circuit between the first terminal and the electrode assembly to prevent the battery from continuing to be charged.

However, in addition to overcharging, during normal use, internal gas may be generated due to an unexpected internal short circuit, and the current cut-off structure is activated to form an open circuit between the first terminal and the electrode assembly. If the car is driving at this time, The secondary batteries in the battery module are connected in series. Since the first terminal and the second terminal are still in an insulated state, the entire battery module is powered off, causing the automobile to suddenly turn off and even cause serious accidents.

Summary of the invention

The present application provides a secondary battery and a battery module that can solve the above problems.

A first aspect of the present application provides a secondary battery including a first terminal, a second terminal, a top cover sheet, an electrode assembly, a connecting member, and a flip sheet,

The electrode assembly includes a first pole piece, a second pole piece, and a partition between the first pole piece and the second pole piece;

At least one of the first terminal and the second terminal is insulated from the top cover sheet; the connecting member is electrically connected to the second terminal;

The flip chip is attached to the first terminal;

In a normal state, the first pole piece is electrically connected to the first terminal through the flip chip, and the second terminal is electrically connected to the second pole piece;

When the pressure in the secondary battery exceeds a reference pressure, the flipper can be flipped to disconnect the flipper from the first pole piece, and the flipped flipper is connected to the flip The pieces are electrically connected to electrically connect the first terminal and the second terminal.

Preferably, the second terminal is electrically insulated from the top cover sheet; one end of the connecting member is electrically connected to the second terminal, the other end extends toward the first terminal, and the connecting member is The top cover is electrically insulated.

Preferably, the first terminal comprises a terminal body and an extension connected to each other, and the extension portion is provided with a first through hole;

The top cover sheet is provided with a second through hole, and the second through hole is opposite to the first through hole;

The flipper seals the first through hole;

The connecting member is located on a side of the top cover sheet away from the electrode assembly, and at least partially opposite to the first through hole.

Preferably, further comprising a housing that covers the top cover sheet, the top cover sheet enclosing a space with the housing, the receiving space including a first chamber for accommodating the electrode assembly, And a second chamber providing a flip space for the flip sheet, the first chamber being out of communication with the second chamber.

Preferably, a first seal is also provided that achieves a seal between the first chamber and the second chamber, the first seal being sealingly coupled between the extension and the top cover sheet.

Preferably, a first seal is also provided that achieves a seal between the first chamber and the second chamber, the first seal being sealed between the flip sheet and the top cover sheet.

Preferably, the flipping piece includes a turning portion and a first protruding head,

The inverting portion is a sheet-like toroidal structure, and an edge thereof is connected to the extending portion;

The first protrusion is connected to the inversion portion and protrudes in a direction in which the connecting member is located, and is opposite to a portion of the first through hole and the connecting member opposite to the first through hole;

In a normal state, the first pole piece is electrically connected to the extension portion through the inversion portion.

Preferably, the conductive sheet is further included; in a normal state, the first pole piece is electrically connected to the first terminal through the conductive sheet and the flip sheet;

When the pressure in the secondary battery exceeds the reference pressure, the flipping sheet can be turned over to disconnect the conductive sheet, thereby disconnecting the electrical connection state of the first terminal and the first pole piece.

Preferably, the conductive sheet comprises a first conductive portion, a second conductive portion and a thinned region,

The thinned region is located between the first conductive portion and the second conductive portion, and has a thickness smaller than a thickness of the first conductive portion and a thickness of the second conductive portion;

The first conductive portion is connected to the flip chip; the second conductive portion is connected to the first pole piece.

Preferably, a resistor is further included, and the first terminal and the top cover sheet are always electrically connected through the resistor.

Preferably, further comprising a second conductive block electrically connected to the first terminal and located on a side of the top cover sheet away from the electrode assembly, the resistor member being disposed in the second Between the conductive block and the top cover sheet.

Preferably, the resistor member is a sheet-like structure, and the second conductive block, the resistor member and the top cover sheet are stacked.

Preferably, a fourth insulating member is further included, the fourth insulating member is insulatively connected between the second conductive block and the top cover sheet, and the resistor member passes through the fourth insulating member.

Preferably, the resistance of the resistor is from 1 to 100,000 ohms.

A second aspect of the present application provides a battery module comprising at least two secondary batteries according to any one of the above, each of the secondary batteries being connected in series with each other.

The technical solution provided by the present application can achieve the following beneficial effects:

In the secondary battery provided by the present application, the connecting member is added, and the flipping piece is attached to the first terminal. When the pressure in the secondary battery exceeds the reference pressure, the flipping piece can be turned over to disconnect the flipping piece from the first pole piece. The state, and the inverted flip chip is electrically connected to the connector to electrically connect the first terminal and the second terminal. Therefore, the secondary battery can not only solve the problem of battery overcharge, but even if the battery module is connected in series, the secondary battery can maintain the entire battery module in a path state as a wire, so that even if the car is in operation, It will suddenly turn off and improve the safety of the car.

The above general description and the following detailed description are merely exemplary and are not intended to limit the application.

DRAWINGS

1 is a schematic structural view of a specific embodiment of a secondary battery provided by the present application;

2 is an exploded view of a specific embodiment of a secondary battery provided by the present application;

Figure 3 is a cross-sectional view taken along line A-A of Figure 1;

4 is a partial schematic view of a specific embodiment of a secondary battery provided by the present application;

FIG. 5 is a schematic structural view of a specific embodiment of a secondary battery flipping sheet provided by the present application; FIG.

6 is a schematic structural view of a specific embodiment of a secondary battery conductive sheet provided by the present application;

7 is another partial structural schematic view of a specific embodiment of a secondary battery provided by the present application;

Figure 8 is a cross-sectional view showing another embodiment of the secondary battery provided by the present application.

Reference mark:

10-top cover sheet;

20-first terminal;

201-terminal body;

202-extension;

21-second conductive block;

22-third insulation member;

23-fourth insulation member;

24-second seal;

30-second terminal;

31-third conductive block;

32-fifth insulation member;

33- sixth insulating member;

34-third seal;

40-connector;

41-first insulating member;

42-first conductive block;

50-resistance piece;

70- flip sheet;

701-turning section;

702-first protrusion;

703-second protrusion;

704-connection;

705-mounting projection;

71-conductive sheet;

711-first conductive portion;

712-thinning zone;

713-second conductive portion;

714-first venting hole;

715-second venting hole;

72-second insulation member;

74 - First seal.

The drawings herein are incorporated in and constitute a part of the specification,

detailed description

The present application will be further described in detail below through specific embodiments and with reference to the accompanying drawings.

As shown in FIG. 1-8, the embodiment of the present application provides a secondary battery including a first terminal 20, a second terminal 30, a top cover sheet 10, an electrode assembly (not shown), a connecting member 40, and The sheet 70 is flipped, and the secondary battery further includes a housing (not shown) that is covered with the top cover sheet 10. The electrode assembly includes a first pole piece, a second pole piece, and a spacer between the first pole piece and the second pole piece.

The top cover sheet 10 seals the casing, and the two enclose a receiving space. The flip chip 70 is attached to the first terminal 20. At least one of the first terminal 20 and the second terminal 30 is electrically insulated from the top cover sheet 10, that is, the first terminal 20 and the second terminal 30 may both be electrically insulated from the top cover sheet 10, or may be only one and the top. The cover sheet 10 is electrically insulated; the connector 40 is electrically connected to the second terminal 30. In a normal state, the first pole piece is electrically connected to the first terminal 20 through the inverting piece 70, and the second pole piece is electrically connected to the second terminal 30; when the pressure in the secondary battery exceeds the reference pressure, the inverting piece 70 can be turned over to flip The sheet 70 is disconnected from the first pole piece, and the inverted flip piece 70 is electrically connected to the connector 40 to electrically connect the first terminal 20 and the second terminal 30.

In the above embodiment, the connecting member 40 is added. One end of the connecting member 40 is electrically connected to the second terminal 30, and the secondary battery is overcharged. When the internal pressure exceeds the reference pressure, the flipping plate 70 can be turned over to turn the flipping plate 70 off. The pole piece is electrically connected, and the inverted flip chip 70 is electrically connected to the connector 40, thereby electrically connecting the first terminal 20 and the second terminal 30. Therefore, after the flipper 70 is turned over, the fault 2 is realized. The internal circuit of the secondary battery is disconnected, and the electrical connection between the flip chip 70 and the connecting member 40 is realized, so that the first terminal 20 and the second terminal 30 of the secondary battery are electrically connected through the connecting member 40, even if the battery module is connected in series. In a manner, the secondary battery can maintain the entire battery module in a passage state as a wire; and when the secondary battery expands or compresses and the cover sheet 10 is welded to the casing, the resulting force is applied to the top cover. The sheet 10, if the flip sheet 70 is disposed on the top cover sheet 10, the deformation of the top cover sheet 10 deforms with the flip sheet 70, which causes stress to be generated inside the flip sheet 70, which stress causes the flip sheet 70 to be sensitive. Drop, thereby affecting the safety of the secondary battery. In the present application, the flip chip 70 is attached to the first terminal 20, which reduces the influence of the flip cover 70 when the cap film 10 is deformed, so that the sensitivity of the flip chip 70 is less likely to occur, which is advantageous for improving the secondary battery. safety. In summary, the secondary battery of the present application does not suddenly turn off the fire even if the automobile is in an operating state, thereby improving the safety of the automobile.

Generally, the first terminal 20 and the second terminal 30 are respectively mounted on the top cover sheet 10, wherein one of the first terminal 20 or the second terminal 30 and the top cover sheet 10 can be directly connected to the top cover sheet 10, Or connected to the top cover sheet 10 through a conductive structure. In order to facilitate the electrical connection between the secondary battery and the outside, the first terminal 20 and the second terminal 30 may both protrude from the top cover sheet 10, especially when electrically insulated from the top cover sheet 10, the electrically insulated end protrudes from the top cover sheet 10 As shown in FIG. 3, the first terminal 20 and the second terminal 30 all protrude from the top cover sheet 10. When the first terminal 20 or the second terminal 30 protrudes from the top cover sheet 10, in order to ensure the sealing property of the first terminal 20 or the second terminal 30 and the top cover sheet 10, it is usually sealed by a seal or a sealant, such as In FIG. 4, the first terminal 20 is sealed to the top cover sheet 10 by the second sealing member 24; as shown in FIG. 7, the second terminal 30 is sealed with the top cover sheet 10 by the third sealing member 34, and the second sealing member 24, The three seals 34 may be seal rings, gaskets, and the like.

The connecting member 40 may be located outside the receiving space, that is, on the side of the top cover sheet 10 away from the electrode assembly, one end of the connecting member 40 is electrically connected to the second terminal 30, the other end extends toward the first terminal 20, and the connecting member 40 and the top The cover sheet 10 is not in contact.

The first terminal 20, the second terminal 30 and the top cover 10 are connected in the following manners:

First, the second terminal 30 is electrically insulated from the top cover sheet 10. The first terminal 20 and the top cover sheet 10 can be electrically connected (as shown in FIG. 8), or can be electrically insulated (as shown in FIGS. 3 and 4). .

When the first terminal 20 is electrically connected to the top cover sheet 10, one end of the connecting member 40 is electrically connected to the second terminal 30, the other end extends toward the first terminal 20, and the connecting member 40 is electrically insulated from the top cover sheet 10 for convenience. After the flipper 70 attached to the first terminal 20 is turned over, it can be electrically connected to the connector 40 quickly.

Second, the second terminal 30 is electrically connected to the top cover sheet 10, and the first terminal 20 is electrically insulated from the top cover sheet 10.

Regardless of which is used, as shown in FIGS. 3 and 4, a first through hole is provided in the first terminal 20, and the inverting piece 70 seals the first through hole. At this time, when the connecting piece 40 is located on the side of the top cover sheet 10 away from the first pole piece, the top cover piece 10 is provided with a second through hole, the second through hole is opposite to the first through hole, and the connecting piece 40 is at least partially A through hole is opposite, in a normal state, the first pole piece is electrically connected to the first terminal 20 through the inversion piece 70; when the pressure in the secondary battery exceeds the reference pressure, the flip piece 70 can be turned over to break the flip piece 70 The electrical connection state of the first pole piece, and the inverted flip chip 70 is electrically connected to the connector 40, so that the first terminal 20 is electrically connected through the flip chip 70, the connector 40, and the second terminal 30. The arrangement of the first through hole and the second through hole makes the setting of the flip sheet 70 more convenient.

In order to facilitate the connection of the first terminal 20 and the flipping plate 70, the first terminal 20 includes a terminal body 201 and an extension portion 202 that are connected to each other. As shown in FIG. 2, the first through hole is provided in the extending portion 202. Generally, the terminal body 201 is sealed with the top cover sheet 10 by the second sealing member 24, and the extension portion 202 and the top cover sheet 10 are sealed by the first sealing member 74 or a sealant or the like, and the top cover sheet 10 is extended at the first terminal 20. At the time, usually one end of the terminal body 201 protrudes from the top cover Slice 10. The terminal body 201 and the extension portion 202 may be of a unitary structure or a separate structure.

Generally, the accommodating space enclosed by the cover sheet 10 and the casing includes a first chamber for accommodating the electrode assembly, and a second chamber for providing a turning space for the flip sheet 70, that is, the flip sheet 70 separates the accommodating space into the first chamber. A chamber and a second chamber, the first chamber and the second chamber are not in communication to ensure that the flip sheet 70 can be turned over when the pressure in the secondary battery exceeds the reference pressure.

Specifically, the sealing of the first chamber and the second chamber may be achieved by the first seal 74 or the sealant or the like. Generally, the first seal 74 is disposed along the outer circumference of the flip sheet 70. When implemented by the first sealing member 74, the first sealing member 74 can be sealingly connected between the first terminal 20 and the top cover sheet 10 (seally connected to the extending portion 202 and the top cover sheet 10 when the extending portion 202 is provided) The first seal 74 is sealingly connected between the flip sheet 70 and the top cover sheet 10. The first sealing member 74 has a first sealing surface in sealing contact with the top cover sheet 10, and a second sealing surface in sealing contact with the extending portion 202 or the flipping sheet 70. Typically, the first sealing surface and the second sealing surface are in the top cover. The height direction of the sheet 10 is opposite; the first sealing surface and the second sealing surface may be opposite to each other in a direction perpendicular to the height direction of the top cover sheet 10, that is, a side seal such as the extension portion 202 or the flip sheet 70 may be extended. a second through hole, the first sealing member 74 is disposed between the inner wall of the second through hole and the extending portion 202 or the flipping plate 70; of course, the first sealing surface and the second sealing surface may also be in the height direction of the top cover sheet 10 at the same time. And opposite in the direction perpendicular to the height direction.

When the first terminal 20 is electrically connected to the top cover sheet 10, the secondary battery may further include a resistor member 50, as shown in FIG. 8. At this time, the first terminal 20 is electrically connected to the top cover sheet 10 through the resistor member 50, and passes through By adding the resistor 50, it is possible to reduce the current of the short circuit when the secondary battery is subjected to the nailing test, and to ensure the safety of the nail. The resistor member 50 may have a columnar structure or a sheet structure.

In order to minimize damage to the pins, the resistance of the resistor 50 is typically from 1 to 100,000 ohms, such as 1 ohm, 100 ohms, 1000 ohms, and 100,000 ohms.

In the above embodiments, the structure of the flipping sheet 70 is as shown in FIG. 3-5, the flipping sheet 70 includes the inverting portion 701 and the first protruding head 702, and the inverting portion 701 is a sheet-like toroidal structure, the edge thereof and the first terminal 20 connection. The first protrusion 702 is connected to the reversing portion 701. Generally, the first protrusion 702 is connected to the central area of the reversing portion 701 and protrudes in the direction in which the connecting member 40 is located. And opposite to the portion of the connector 40 opposite to the first through hole. In the normal state, the first pole piece is electrically connected to the first terminal 20 through the inverting portion 701. By increasing the first boss 702, the distance between the flip sheet 70 and the connector 40 in the flip direction of the flip sheet 70 can be reduced, so that the flip sheet 70 can quickly come into contact with the connector 40 when overcharging occurs.

Preferably, the first projection 702 extends into the second through hole to reduce the stroke of the flipping of the flipping plate 70.

In order to further reduce the stroke of the flipping of the flipping plate 70, and to ensure the reliability of the connection of the flipping plate 70 and the first pole piece, the flipping plate 70 further includes a second protruding head 703, and the second protruding head 703 is coupled to the inverting portion 701 and is convex. In the direction in which the first pole piece is located, the flipping portion 701 is electrically connected to the first pole piece through the second boss 703 in the normal state.

The end surface of the first protrusion 702 and the end surface of the second protrusion 703 are planar structures to increase the contact area between the flip sheet 70 and the first pole piece and the inverted flip sheet 70 and the connector 40, thereby increasing the overcurrent area.

The inverting portion 701 may be entirely located in the first through hole or may be connected to the end of the first through hole. Preferably, the circumference of the inverting portion 701 is connected to the inner wall of the first through hole to shorten the turning stroke of the flip sheet 70 while ensuring The connection reliability with the first pole piece and the connecting member 40 before and after the flipping.

Further, in order to ensure the reliability of the connection between the flip sheet 70 and the top cover sheet 10, the peripheral edge of the reversing portion 701 is further provided with a connecting portion 704. The thickness of the connecting portion 704 is greater than the thickness of the reversing portion 701, and the thickness refers to the flipping along the flipping sheet 70. The size of the direction, the inverting portion 701 is connected to the first through hole through the connecting portion 704.

The first through hole is preferably a stepped hole. As shown in FIG. 4, the connecting portion 704 is overlapped with the stepped surface of the stepped hole. When only the inverting portion 701 is provided, the inverting portion 701 may be overlapped on the stepped surface. The structure can limit the position of the flipping piece 70, and prevent the loosening of the flipping piece 70 from the first terminal 20 in the normal state, so that the flipping piece 70 cannot be brought into contact with the connecting member 40 after being turned over.

Generally, in the projection along the axial direction of the first through hole, the edge of the second through hole is located inside the reversing portion 701, especially when the first protruding end 702 protrudes into the second through hole, the flip sheet 70 and the The loose connection of one terminal 20 causes the false contact of the flip chip 70 with the connector 40 in the normal state.

For convenience of connection, the secondary battery further includes a conductive sheet 71. As shown in FIG. 4, in a normal state, the first pole piece is electrically connected to the first terminal 20 through the conductive sheet 71 and the flip sheet 70 in sequence; When the pressure exceeds the reference pressure, the flipping sheet 70 can be turned over to break the conductive sheet 71, thereby breaking the electrical connection state of the first terminal 20 and the first pole piece, and the conductive sheet 71 is added to facilitate processing and assembly.

Specifically, as shown in FIG. 6 , the conductive sheet 71 includes a first conductive portion 711 , a second conductive portion 713 , and a thinned region 712 , and the thinned region 712 is located between the first conductive portion 711 and the second conductive portion 713 , and The thickness of the first conductive portion 711 is smaller than the thickness of the second conductive portion 713; wherein the first conductive portion 711 is connected to the flipping plate 70, and when the second protruding portion 703 is provided, directly connected to the second protruding portion 703 The second conductive portion 713 is connected to the first pole piece. In the normal state, the flip chip 70 is electrically connected to the first pole piece through the first conductive portion 711, the thinned region 712, and the second conductive portion 713. By providing the thinned region 712, the first conductive portion 711 is connected to the flip sheet 70, and the second conductive portion 713 is connected to the first pole piece. When the flip sheet 70 is turned over, the conductive sheet 71 can be quickly turned on in the thinned region 712. The break is broken, so that the open circuit in the secondary battery is quickly realized.

Generally, the conductive sheet 71 is provided with a vent hole, and the vent hole is opposite to the flip sheet 70. As shown in FIGS. 4 and 6, the first vent hole 714 or the second vent hole 715 is provided, and the first vent hole 714 and the first vent hole may be simultaneously provided. Two vents 715. The first vent hole 714 and the second vent hole 715 penetrate the conductive sheet 71 in the reverse direction of the flip sheet 70 so that the gas in the secondary battery can flow to the flip sheet 70, and the flip sheet 70 can be inverted. When the reversing portion 701 is provided, in order to ensure the inner short-circuit gas generation, the gas quickly reaches the reversing portion 701, and the second vent hole 715 faces the reversing portion 701.

Further, in order to be able to pull off the conductive sheet 71 under a small pulling force, the thinned portion 712 may be provided with an indentation and a broken portion, or only one of an indentation and a broken portion may be provided, wherein When the disconnecting portion is provided, the first conductive portion 711 and the second conductive portion 713 are disconnected at the disconnecting portion.

Generally, the first conductive portion 711 is further provided with a mounting hole, the flipping plate 70 is provided with a mounting protrusion 705, the mounting protrusion 705 can be connected to the second protruding head 703, and the mounting protrusion 705 is inserted into the mounting hole to ensure the conductive sheet 71 and the flipping The connection accuracy of the sheet 70 ensures that the conductive sheet 71 can be broken by a predetermined pulling force. The mounting hole can be a through hole or a blind hole, and the through hole is The mounting hole and the first ventilation hole 714 may be the same through hole.

In order to prevent electrical contact between the conductive sheet 71 and the first terminal 20, the contact between the conductive sheet 71 and the first terminal 20 is achieved by an insulating structure, an insulating glue or an insulating varnish, and the insulating structure may be the second in FIG. The insulating member 72, the second insulating member 72 is located between the conductive sheet 71 and the flipping plate 70, and the second insulating member 72 is provided with a third through hole, and the flipping sheet 70, the third through hole and the first conductive portion 711 are opposite to each other.

The second conductive portion 713 can be fixed to the first terminal 20 by means of bonding, screwing, etc., in order to better fix the conductive sheet 71 and thereby ensure that the flip sheet 70 can be electrically disconnected therefrom after being turned over, the conductive sheet 71 can pass through the second insulation. The member 72 is fixed to the first terminal 20. In this manner, the second insulating member 72 serves as both insulation and fixing, thereby saving the number of components and simplifying the assembly process.

In the above embodiments, as shown in FIG. 4, the secondary battery further includes a first conductive block 42. The portion of the connecting member 40 opposite to the first through hole is connected with the first conductive block 42, the first conductive block 42 and the first conductive block 42. A through hole is opposed to further shorten the time during which the flip chip 70 is electrically connected to the connector 40 after being turned over.

The first conductive block 42 is not in contact with the top cover sheet 10, and an insulating glue or a first insulating member 41 is disposed therebetween. The first insulating member 41 is provided with a third through hole, and the first conductive block 42 The three through holes are opposite to the first through holes.

In order to prevent the position of the first conductive block 42 from being displaced, the first insulating member 41 is provided with a third groove, and the first conductive block 42 is inserted into the third groove. The first insulating member 41 is mounted to the top cover sheet 10.

Since only one end of the connecting member 40 is connected to the second terminal 30, the cantilever structure is easily caused. After the flipping plate 70 is turned over, the impact force of the flipping plate 70 causes the connecting member 40 to be away from the end of the second terminal 30, away from the top cover sheet 10. The direction of movement causes the flipping plate 70 to be in contact with the connecting member 40 after being turned over. For this reason, one end of the connecting member 40 away from the second terminal 30 is connected to the top cover sheet 10 through the first insulating member 41, and the connection manner may be bonding. Card connection, etc.

Further, in order to prevent the air pressure of the second chamber from obstructing the inversion of the inverting piece 70, the top cover sheet 10 is further provided with a vent hole which faces the flip sheet 70 and penetrates in the thickness direction of the top cover sheet 10.

In order to further facilitate the electrical connection of the first terminal 20 to the outside, the secondary battery further includes The second conductive block 21, especially when the resistor 50 is provided, the resistor 50 is disposed between the top cover 10 and the second conductive block 21, and the top cover 10 passes through the resistor 50, the second conductive block 21, and the first The terminal 20 is electrically connected. When the resistor member has a columnar structure, the second conductive block 21 and the top cover sheet 10 are electrically insulated by the fourth insulating member 23 or insulating varnish and insulating glue, that is, the second conductive block 21 and the top cover sheet. The electrical connection is made by the direct contact between the 10 and the electrical contact. When the resistor member 50 has a sheet-like structure, the second conductive block 21, the resistor member 50 and the top cover sheet 10 are stacked to increase the reliability of the connection.

Further, the top cover sheet 10 is provided with a first recess, one end of the resistive member 50 electrically connected to the top cover sheet 10 is inserted into the first recess; and the second conductive block 21 is provided with a second recess, and the resistor member 50 is further One end is inserted into the second recess to prevent misalignment of the resistor 50; of course, only the top cover 10 may be provided with a first recess, or the second conductive block 21 may be provided with a second recess.

In order to facilitate the electrical connection between the connector 40 and the second terminal 30 when the second terminal 30 is electrically insulated from the top cover 10, the secondary battery further includes a third conductive block 31, and the third conductive block 31 and the top cover 10 are electrically Insulation, which can be insulated by a sixth insulating member 33, an insulating paste or an insulating varnish.

When the first terminal 20 or the second terminal 30 is electrically insulated from the top cover sheet 10, it may be realized by an insulating member, an insulating glue or an insulating varnish. As shown in FIG. 4, the first terminal 20 passes through the third insulating member 22 and the top cover sheet 10. Electrically insulated; as shown in FIG. 7, the second terminal 30 is electrically insulated from the top cover sheet 10 by a fifth insulating member 32. The third insulating member 22 and the second insulating member 72 may have a unitary structure.

In the above embodiments, generally, the first terminal 20 is a positive terminal, and the second terminal 30 is a negative terminal. Accordingly, the first pole piece is a positive electrode piece, and the second pole piece is a negative electrode piece, especially at the first terminal 20 When the cover sheet 10 is electrically connected, the electrolyte is prevented from corroding the casing. Of course, the first terminal 20 is a negative terminal, and the second terminal 30 is a positive terminal. Accordingly, the first pole piece is a negative electrode piece, and the second pole piece is a positive electrode piece.

The present application also provides a battery module comprising the secondary battery provided by any of the above embodiments. The secondary battery is provided in plurality, and the secondary batteries may be connected in parallel with each other or in series with each other. Especially in the case of series connection, the secondary battery of any of the above embodiments is used, and even if an accident occurs, the flip sheet 70 is activated, Will cause the entire battery module to be powered down, thus ensuring electricity The stability of the pool module.

The above description is only the preferred embodiment of the present application, and is not intended to limit the present application, and various changes and modifications may be made to the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application are intended to be included within the scope of the present application.

Claims (15)

A secondary battery comprising a first terminal, a second terminal, a top cover sheet, an electrode assembly, a connecting member and a flip sheet, The electrode assembly includes a first pole piece, a second pole piece, and a partition between the first pole piece and the second pole piece; At least one of the first terminal and the second terminal is insulated from the top cover sheet; the connecting member is electrically connected to the second terminal; The flip chip is attached to the first terminal; In a normal state, the first pole piece is electrically connected to the first terminal through the flip chip, and the second terminal is electrically connected to the second pole piece; When the pressure in the secondary battery exceeds a reference pressure, the flipper can be flipped to disconnect the flipper from the first pole piece, and the flipped flipper is connected to the flip The pieces are electrically connected to electrically connect the first terminal and the second terminal. The secondary battery according to claim 1, wherein said second terminal is electrically insulated from said top cover sheet; one end of said connecting member is electrically connected to said second terminal, and the other end is toward said first A terminal extends and the connector is electrically insulated from the cap piece. The secondary battery according to claim 2, wherein the first terminal comprises a terminal body and an extension connected to each other, and the extension portion is provided with a first through hole; The top cover sheet is provided with a second through hole, and the second through hole is opposite to the first through hole; The flipper seals the first through hole; The connecting member is located on a side of the top cover sheet away from the electrode assembly, and at least partially opposite to the first through hole. The secondary battery according to claim 3, further comprising a housing that covers the top cover sheet, the top cover sheet and the housing enclose a receiving space, and the receiving space includes And a second chamber for accommodating the electrode assembly, and a second chamber for providing an inversion space for the flip sheet, the first chamber being out of communication with the second chamber. The secondary battery according to claim 4, further comprising a first seal that achieves a seal between the first chamber and the second chamber, the first seal being sealingly connected to the Between the extension and the cover sheet. The secondary battery according to claim 4, further comprising a first seal that achieves a seal between the first chamber and the second chamber, the first seal being sealed to the Between the flipping sheet and the top cover sheet. The secondary battery according to claim 3, wherein the inverting piece comprises a reversing portion and a first protruding end, The inverting portion is a sheet-like toroidal structure, and an edge thereof is connected to the extending portion; The first protrusion is connected to the inversion portion and protrudes in a direction in which the connecting member is located, and is opposite to a portion of the first through hole and the connecting member opposite to the first through hole; In a normal state, the first pole piece is electrically connected to the extension portion through the inversion portion. The secondary battery according to claim 1, further comprising a conductive sheet; in a normal state, the first pole piece is electrically connected to the first terminal through the conductive sheet and the flip sheet in sequence; When the pressure in the secondary battery exceeds the reference pressure, the flipping sheet can be turned over to disconnect the conductive sheet, thereby disconnecting the electrical connection state of the first terminal and the first pole piece. The secondary battery according to claim 8, wherein the conductive sheet comprises a first conductive portion, a second conductive portion, and a thinned region, The thinned region is located between the first conductive portion and the second conductive portion, and has a thickness smaller than a thickness of the first conductive portion and a thickness of the second conductive portion; The first conductive portion is connected to the flip chip; the second conductive portion is connected to the first pole piece. The secondary battery according to any one of claims 2 to 9, further comprising a resistor, wherein the first terminal and the top cover are always electrically connected through the resistor. The secondary battery according to claim 10, further comprising a second conductive block electrically connected to said first terminal and located at said top cover sheet away from said electrode assembly On one side, the resistor is disposed between the second conductive block and the top cover sheet. The secondary battery according to claim 11, wherein the resistor member has a sheet-like structure, and the second conductive block, the resistor member, and the top cover sheet are laminated. The secondary battery according to claim 11, further comprising a fourth insulating member electrically connected between the second conductive block and the top cover sheet, the resistor member Passing through the fourth insulating member. The secondary battery according to claim 10, wherein the resistance member has a resistance of 1 to 100,000 ohms. A battery module comprising at least two secondary batteries according to any one of claims 1 to 14, each of the secondary batteries being connected in series.

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