CN109920965B - Current interrupting device and notched part thereof, battery cover assembly, single battery, battery module, power battery and electric vehicle - Google Patents

Abstract

The present disclosure discloses a current interruption device, a scored piece thereof, a battery cover plate assembly, a single battery, a battery module, a power battery and an electric automobile. The scoring member includes a scoring area formed with a score, a first welding area for electrically interconnecting with the flip member and a second welding area for electrically interconnecting with the electrode internal terminal, the flip member being operable under air pressure to break electrical connection with the scoring member by snapping the score, the score surrounding the first welding area and being disposed out of plane with the first welding area and/or the second welding area. Because the nick on the nick piece and at least one of the first welding area and the second welding area are not in the same plane, the mechanical impact of the external force transmitted by the turnover piece to the nick on the nick piece can be effectively eliminated, the thermal influence of the welding stress of the first welding area on the nick area can be eliminated, and the reliability of the current interruption device is improved.

Description

Current interrupting device and notched parts thereof, battery cover assembly, single battery, battery module, power battery and electric vehicle

Technical Field

The present disclosure relates to the field of batteries, and in particular, to a current interruption device and a notched part thereof, a battery cover assembly using the current interruption device, a single battery using the battery cover assembly, a battery module using the single battery, a power battery using the battery module, and a vehicle using the power battery.

Background Art

As an energy storage unit, batteries play an important role in all walks of life. For example, power batteries are widely used in new energy vehicles and other fields. The battery pack of the power battery can have multiple single cells connected in series or in parallel to form a battery module to achieve charging and discharging. During the charging and discharging process, the power battery usually uses the BMS (battery management system) to monitor the changes in voltage and current to calculate the state of charge. If there is a problem with the voltage sampling, it may cause the battery to overcharge, especially for the ternary system. If the overcharge reaches a certain level, there will be a risk of battery combustion and explosion.

Existing technical solutions: monitor the voltage and current of the battery, calculate the battery power through the current integration method and the open circuit voltage method, and use this to control the battery charging and discharging management. However, there are also shortcomings, such as failure of battery voltage sampling or current sampling, or software failure, which leads to long-term uncontrolled charging of the battery, especially in the case of charging with a charging pile, when the communication between the charging pile and the battery manager fails, overcharging cannot be controlled, and the battery overcharges to a certain extent, which will cause the battery to swell or even explode and catch fire.

Therefore, it is of positive significance to provide a current interruption technology that can forcibly disconnect the charging and discharging circuit by itself.

Summary of the invention

The purpose of the present disclosure is to provide a current interruption device and a notched part thereof, a battery cover assembly using the current interruption device, a single cell using the battery cover assembly, a battery module using the single cell, a power battery using the battery module, and a vehicle using the power battery.

In order to achieve the above-mentioned purpose, the present disclosure provides a notched piece of a current interrupt device, which includes a notched area with a notch formed therein, a first welding area for electrically connecting to a flip piece, and a second welding area for electrically connecting to an inner terminal of an electrode, wherein the flip piece can be actuated under the action of gas pressure to disconnect the electrical connection with the notched piece by breaking the notch, wherein the second welding area, the notched area, and the first welding area are arranged sequentially from the outside to the inside in a radial direction, and are formed into a step structure gradually approaching the flip piece from the outside to the inside, and the notch is arranged around the first welding area.

Optionally, a boss protruding from the scoring area is formed on the scoring member, the first welding area is formed by the upper surface of the boss and is parallel to the scoring area, and an annular welding spot is provided on the outer periphery of the upper surface.

Optionally, an annular wall protruding in the opposite direction of the boss is formed on the outer periphery of the notched area, the second welding area is formed on the outer periphery of the annular wall and is parallel to the notched area, and an annular welding point is formed on the outer periphery of the second welding area.

Optionally, the side wall of the boss and the annular wall are respectively perpendicular to the notched area.

Optionally, the first welding area, the notched area and the second welding area form ring structures respectively.

The present disclosure also provides a current interruption device, comprising a notched piece and a flip piece, wherein the notched piece is the notched piece provided by the present disclosure, and the notched piece is electrically connected to the flip piece through the first welding area.

The present disclosure also provides a battery cover plate assembly, including a cover plate, an inner electrode terminal located on the inner side of the cover plate, and an outer electrode terminal located on the outer side of the cover plate, the inner electrode terminal and the outer electrode terminal are electrically connected through a current interruption device, the current interruption device is the current interruption device provided by the present disclosure, the outer electrode terminal is electrically connected to the flip piece, and the notched piece is electrically connected to the inner electrode terminal.

Optionally, a support ring is sealed between the lower side of the outer periphery of the flip member and the cover plate, and the outer periphery of the electrode external terminal is electrically connected to the upper side of the outer periphery of the flip member.

Optionally, a support flange is formed on the inner wall of the support ring, and the outer peripheries of the flip member and the electrode outer terminal are supported on the upper surface of the support flange.

The present disclosure also provides a single battery, which includes an outer shell, a battery cell accommodated in the outer shell, and a battery cover assembly that encapsulates the outer shell. It is characterized in that the battery cover assembly is the battery cover assembly provided by the present disclosure, the inner electrode terminal is electrically connected to the battery cell, and the flip piece is connected to the internal gas of the outer shell.

The present disclosure also provides a battery module, in which the single battery provided by the present disclosure is arranged.

The present disclosure also provides a power battery, including a housing and a battery module arranged in the housing, wherein the battery module is the battery module provided by the present disclosure.

The present disclosure also provides an electric vehicle, which is provided with the power battery provided by the present disclosure.

Through the above technical solution, since the notch on the notch part and the other two welding areas are not in the same plane and form a step structure, the mechanical impact of the external force transmitted from the flip part and the terminal inside the electrode on the notch on the notch part can be effectively eliminated, and the thermal influence of the welding stress of the two welding areas on the area where the notch is located can also be eliminated, thereby improving the reliability of the current interruption device.

Other features and advantages of the present disclosure will be described in detail in the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

FIG1 is a partially exploded perspective view of a battery module in an exemplary embodiment of the present disclosure;

2 is a cross-sectional view of a current interruption device in a first exemplary embodiment of the present disclosure;

FIG. 3 is a cross-sectional view of a current interruption device in a second exemplary embodiment of the present disclosure.

FIG4 is a schematic diagram of a three-dimensional structure of a scoring member provided by the present disclosure based on a second exemplary embodiment;

FIG5 is a schematic diagram of a three-dimensional structure of a flip member provided by the present disclosure based on the first exemplary embodiment;

FIG6 is a cross-sectional schematic diagram of a battery cover assembly according to a current interruption device in the first embodiment of the present disclosure.

DETAILED DESCRIPTION

The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

In the present disclosure, unless otherwise specified, directional words such as "up, down, left, right" are generally defined based on the drawing direction of the corresponding drawings, and "inside and outside" refer to the inside and outside of the corresponding component outline.

As shown in Figures 1 to 6, the present disclosure provides a current interrupt device and its notched parts, flip parts, a battery cover assembly using the current interrupt device, a single cell using the battery cover assembly, a battery module using the single cell, a power battery using the battery module, and a technical solution for a vehicle using the power battery. As shown in Figure 1, the current interrupt device is arranged between the electrode external terminal 112 and the corresponding electrode internal terminal to cut off the circuit inside and outside the battery. Among them, in the single cell, a plurality of single cells are connected in series or in parallel into a battery module, and can be placed in a battery pack to form a power battery. In addition, in addition to the field of power batteries, the various technical solutions provided in the present disclosure can also be widely used in other battery fields. Specifically, the present disclosure introduces the current interrupt device involved through two embodiments. Each embodiment will be described in detail below in conjunction with the accompanying drawings.

First, as shown in FIG. 1 , each embodiment of the present disclosure provides a battery module, including a plurality of single cells, wherein the single cell may include a housing 111, a cell contained in the housing, an electrode inner terminal 109 electrically connected to the cell, and a cover plate 110 of the housing, wherein the electrode outer terminal 112 is provided on the cover plate, so as to complete the input and output of current through various electrode lead-out members 119. The current interruption device is provided between the electrode outer terminal and the electrode inner terminal to control the input and output of current of the electrode terminal. That is, the current interruption device is in a state where the cell is turned on in the normal state in the single cell, at which time the electrode terminal can normally input and output current to complete the charge and discharge work of the single cell, and in a dangerous state, such as when the battery is overcharged, the current interruption device can interrupt the current input and current output of the electrode terminal, thereby avoiding problems such as overcharging of the battery. Therefore, as an important safety measure, the reliability of the current interruption device is crucial, that is, the current interruption device needs to respond quickly.

In the present disclosure, the current interruption device in each embodiment is a mechanical structure that senses air pressure. Specifically, the current interruption device is connected to the gas inside the shell of the single battery and can act under air pressure to interrupt the current flowing through. Specifically, the transmission of current can be interrupted by disconnecting the internal component connection, thereby timely cutting off the charging and discharging of the battery. The source of the air pressure used is: when the battery is in a dangerous state such as overcharging, gas will be generated inside the battery, which will increase the air pressure inside the shell, or when the battery is abnormal during use, the battery temperature will increase, which will increase the air pressure inside the battery, thereby generating air pressure power to drive the current interruption device.

Taking the embodiment as shown in FIG. 2 to FIG. 3 as an example, the current interruption device has a notched member 101 and a flip member 102 connected to the notched member 101 to be electrically connected to each other, and the flip member 102 and the notched member 101 can be electrically disconnected under the action of gas pressure. In the embodiment of the present disclosure, at least one of the two can be disconnected, for example, by machining a weak notch on the corresponding component to achieve the disconnection of the structure itself, thereby achieving the disconnection of the electrical connection, and specifically, a notch 104 is formed on the notched member 101. That is, under the action of internal gas pressure, the notch 104 can be pulled off by the flipping action of the flip member 102 to achieve the disconnection of the electrical connection between the two, thereby achieving the purpose of cutting off the transmission of current.

The reason for adopting this method is that in the field of power batteries, for example, a large current needs to be passed, so it is necessary to ensure that the welding structure of the notched member 201 and the flip member 202 is stable to avoid the welding structure being melted by a large current. In this way, by setting the notch 104 of the notched member 101, that is, processing a weak part with a strength lower than that of other areas in the corresponding part, the notched member 101 and the flip member 102 can be completely disconnected. The notch is usually set around the welding area of the notched member and the flip member to ensure the complete disconnection of the two.

The scoring member 101 and the flip member 102 in two embodiments of the present disclosure are described below in conjunction with FIG. 2 and FIG. 3 .

As shown in FIG. 2 and FIG. 3 , the present disclosure provides a notched member of a current interruption device, wherein the notched member 101 includes a notched area 105 formed with a notch 104, a first welding area 103 for being electrically connected to a flip member 102, and a second welding area 107 for being electrically connected to an electrode inner terminal, and the flip member 102 can be moved under the action of gas pressure to disconnect the electrical connection with the notched member 101 by pulling off the notch 104, wherein in the present disclosure, the notch 104 surrounds the first welding area 103 and is arranged in a different plane from the first welding area 103 and/or the second welding area 107. That is, the plane where the notch 104 is located and at least one of the first welding area 103 and the second welding area 107 are not in the same plane, so that the mechanical impact of the external force transmitted by the flip member 101 on the notched member 101 can be effectively eliminated, and the thermal influence of the welding stress of the welding area on the area where the notch 104 is located can also be eliminated. Thus, the reliability of the current interruption device provided by the present disclosure is improved. The notch 104 surrounding the first welding area 103 can be disconnected under the effect of the internal gas pressure of the battery, and at this time, the electrical connection between the flip member 102 and the notch member 101 is completely disconnected, thereby interrupting the current.

Further, as shown in Figures 3 and 4, in the second embodiment, the notch 104 is arranged on a different plane from the first welding area 103 and the second welding area 107. Specifically, the second welding area 107, the notch area 105, and the first welding area 103 are arranged in sequence from the outside to the inside in the radial direction, and form a step structure that gradually approaches the flip piece 102 from the outside to the inside. The second welding area 107 is also not on the same plane as the notch area 105, and the step structure formed by the three has a buffering effect, which can avoid the thermal influence of the welding stress of the two welding areas on the notch 104, and can also buffer the external force transmitted from the direction of the inner terminal of the electrode, so that the current interruption device is more reliable.

Specifically, in two embodiments of the present disclosure, as shown in FIG. 2 or FIG. 3, the notched member 101 includes a boss 106 protruding from the notched area 105, the first welding area 103 is formed on the boss 106, and the notch 104 formed on the notched area 105 is arranged around the boss 106. Thereby, the two regions are not aligned with each other. More specifically, the first welding area 103 is formed by the upper surface of the boss 106 and is parallel to the notched area 105, and the outer periphery of the upper surface is provided with an annular welding spot. Correspondingly, the first connection area 115 on the flip member 102 can be formed as a connection hole for accommodating the boss 106. Thereby, the outer periphery of the boss and the inner wall of the connection hole are firmly welded by the annular welding spot. The boss can be a cylindrical structure, or it can have a through-hole structure in the axial direction of the cylindrical structure; in other embodiments, the two regions can also be arranged with various convex or concave structures.

Further, as shown in FIG. 2 , in the first embodiment, in order to electrically connect with the inner electrode terminal 109 of the battery, a receiving groove is usually provided at the top of the inner electrode terminal 109. For this purpose, the outer periphery of the notched area 105 is formed with an annular wall 108 protruding in the same direction as the boss, and the upper edge of the annular wall 108 is aligned with the upper edge of the boss 106 in the height direction, wherein the second welding area 107 is formed on the outer periphery of the annular wall 108 and is aligned with the upper edge of the boss in the height direction, that is, the upper edge of the outer wall of the annular wall is used to electrically connect with the inner electrode terminal 109 of the battery to form a second welding area, and is matched with the groove wall shape of the receiving groove of the inner electrode terminal 109 and welded through an annular welding point, and in this embodiment, the notched member 101 can be completely accommodated in the receiving groove of the inner electrode terminal 109, and the structure is stable. That is, in the first embodiment, the first welding area 105 and the second welding area 107 are coplanar, and at the same time are not in the same plane as the notched area 105.

As shown in FIG3 , in the second embodiment, the electrode inner terminal 109 is still provided with a receiving groove, and the boss 106 of the notched member 101 extends out of the receiving groove. Specifically, the outer periphery of the notched area 105 is formed with an annular wall 108 that is opposite to the boss 106, and the second welding area 107 is formed on the outer periphery of the annular wall 108 and is parallel to the notched area 105, so that the notched member 101 is formed into the above-mentioned step structure, wherein the outer periphery of the second welding area 107 is formed with an annular welding spot for electrical connection with the electrode inner terminal 109 of the battery, specifically, the lower surface of the second welding area 107 can be placed on the bottom wall of the receiving groove, and the outer periphery is welded to the side wall of the receiving groove through the annular welding spot, and the structure is also stable. That is, in the second embodiment, the first welding area 103, the notched area 105 and the second welding area 107 are all arranged on different surfaces.

In the second embodiment, as shown in FIG3 , the side wall and the annular wall 108 of the boss are respectively perpendicular to the notched area 105, and in other embodiments, they may also have a certain angle, such as forming a Z-shaped step. In addition, the first welding area 103, the notched area 105, and the second welding area 107 may be annular structures, that is, the first welding area 103 has a central hole, and in other embodiments, the first welding area 103 may not have a central hole.

The notching member 101 in two embodiments is introduced above, and the flipping member 102 in two embodiments is introduced below.

As shown in FIGS. 2 to 5 , the flip member 102 is formed with a first connection area 115 for electrically connecting to the notched member 101 and a second connection area 116 for electrically connecting to the electrode external terminal 112 of the battery. As shown in FIGS. 2 and 5 , a deformation buffer area 117 is also formed on the flip member 102. The deformation buffer area 117 is arranged between the first connection area 115 and the second connection area 116 and is arranged around the first connection area 115. The deformation buffer area refers to the area that can be deformed before the flip member 102 itself, the first connection area 115, the second connection area 116 and the notched member 101 itself under the action of external force, thereby buffering the external force. Then, the impact of the external force on the first connection area 115 and the notch 104 on the notched member 101 is reduced, and the reliability of the current interruption device is improved.

Among them, in two embodiments of the present disclosure, the flip member 102 is a sheet-like structure formed into a cone, the small end of the cone forms the first connection area 115, and the large end is away from the notch member 101 and forms the second connection area 116. The cone structure can set the two connection areas on different planes, and can provide a space for the flip member 102 to be turned upward by force to break the notch 104. In other possible embodiments, the flip member can also be a plane member with elasticity, etc.

As shown in FIG. 2 and FIG. 5 , the deformation buffer 117 in the present disclosure is formed as an annular groove structure surrounding the first connection area 115. In this way, under the action of external force, the deformation buffering effect can be achieved through the relative movement between the groove walls of the annular groove. In other possible implementations, the deformation buffer 117 can also be implemented by a structure such as a deformation chamber or an elastic material.

As shown in FIG. 2 and FIG. 5 , in the first embodiment, the radial cross section of the annular groove structure is an arc, such as a semicircular shape protruding toward the electrode outer terminal 112. In this way, the external force transmitted from the second connection area 116 can be absorbed by the deformation of the arc-shaped groove wall, thereby reducing the impact on the first connection area 115 and the notched member 101. In other possible embodiments, the cross section of the annular groove can also be an angular shape, that is, the cross section has two angled sides, which can also play a buffering role.

As shown in FIG. 3 , in the second embodiment, the boss 106 of the notch member 101 protrudes out of the receiving groove of the inner terminal of the electrode.

As shown in Figures 2 and 3, in the two embodiments of the present disclosure, in order to ensure that the gas inside the battery can be acted upon, a support ring 113 is sealed between the lower side of the outer periphery of the flip member 102 and the cover plate 110, and the outer periphery of the electrode external terminal 112 is electrically connected to the upper side of the outer periphery of the flip member 102, so that the gas generated from the inside of the battery can act on the flip member 102 without leaking out. In order to enable the flip member 102 to operate normally, the electrode external terminal 112 is formed as a cap structure and can be formed with a through hole 118 for discharging gas when the flip member 102 operates, thereby avoiding the flip member from operating in reverse under the action of gas pressure. In addition, in the two embodiments of the cover plate 110 being charged and insulated, the support ring 113 can be supported by an insulating material or a conductive material. Generally, the support ring 113 can be a ceramic ring so that the cover plate 110 is insulated and not charged. Specifically, a support flange 114 is formed on the inner wall of the support ring 113 , and the outer peripheries of the flip member 102 and the electrode outer terminal 112 are supported on the upper surface of the support flange 114 to ensure stable operation of the current interruption device.

The current interruption device provided by the present disclosure includes the above-mentioned notched member 101 and the above-mentioned flip member 102 , and the notched member 101 is electrically connected to the flip member 102 via the first welding area 103 .

The battery cover plate assembly provided by the present disclosure, as shown in Figure 6, includes a cover plate 110, an inner electrode terminal 109 located on the inner side of the cover plate 110, and an outer electrode terminal 112 located on the outer side of the cover plate 110. The inner electrode terminal 109 and the outer electrode terminal 112 are electrically connected through the above-mentioned current interruption device, the outer electrode terminal 112 is electrically connected to the flip member 102, and the notched member 101 is electrically connected to the inner electrode terminal 109.

The inner electrode terminal is welded to the inner lead-out member 120 electrically connected to the battery cell. Specifically, a welding hole can be formed on the inner lead-out member 120. The inner electrode terminal 109 is formed into a columnar structure and embedded in the welding hole to be welded with the inner lead-out member 120. In order to prevent the cover plate 110 from being charged, a cover plate insulating member 122 is provided between the cover plate 110 and the inner lead-out member 102. The inner electrode terminal can pass through the cover plate insulating member with a gap to be welded with the notched member 101. In addition, in order to ensure the sealing, the lower end of the support ring 113 is welded to the cover plate, wherein ceramic can be selected as the material to ensure the insulation of the current interruption device and the cover plate 110. A hole is formed on the cover plate to facilitate the installation of the current interruption device. In addition, in order to ensure that the gas inside the battery can act on the flip member 102, an air hole 121 is formed on the inner lead-out member 120, so that the gas can act on the flip member 102 through the air hole 121.

The single battery provided by the present disclosure includes a shell 111, a battery cell contained in the shell, and the above-mentioned battery cover assembly that seals the shell, the electrode inner terminal 109 is electrically connected to the battery cell, and the flip member 102 is connected to the internal gas of the shell.

The present disclosure provides a battery module, in which the above-mentioned single battery is arranged.

The power battery provided by the present disclosure includes a housing and the above-mentioned battery module arranged in the housing.

The present disclosure provides an electric vehicle, which is provided with the above-mentioned power battery.

The five embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims (10)

1. A notched member of a current interrupting device, the notched member (101) comprising a notched area (105) formed with a notch (104), a first welding area (103) for being electrically connected to a flip member (102), and a second welding area (107) for being electrically connected to an electrode inner terminal (109), the flip member (102) being able to move under the action of gas pressure to disconnect the electrical connection with the notched member (101) by breaking the notch (104), characterized in that the notch (104) surrounds the first welding area (103) and is arranged on a different plane from the first welding area (103) and the second welding area (107); The second welding area (107), the notched area (105), and the first welding area (103) are arranged in sequence from the outside to the inside in a radial direction, and form a step structure that gradually approaches the flip part (102) from the outside to the inside, and the notch (104) is arranged around the first welding area (103); The notched member (101) comprises a boss (106) protruding from the notched area (105), the first welding area (103) is formed on the boss (106), and the notch (104) is formed on the notched area (105) and arranged around the boss (106); The outer periphery of the notched area (105) is formed with an annular wall (108) protruding in the opposite direction to the boss (106); the second welding area (107) is formed on the outer periphery of the annular wall (108) and is parallel to the notched area (105); an annular welding spot is formed on the outer periphery of the second welding area (107); the first welding area (103) is formed by the upper surface of the boss (106) and is parallel to the notched area (105); and an annular welding spot is provided on the outer periphery of the upper surface; The first welding area (103), the notched area (105) and the second welding area (107) are respectively formed into annular structures. 2. The scoring member according to claim 1, characterized in that the side wall of the boss (106) and the annular wall (108) are respectively perpendicular to the scoring area (105). 3. A current interruption device, comprising a notched piece (101) and a flip piece (102), characterized in that the notched piece (101) is the notched piece (101) according to any one of claims 1 to 2, and the notched piece (101) is electrically connected to the flip piece (102) via the first welding area (103). 4. A battery cover assembly, comprising a cover (110), an inner electrode terminal (109) located on the inner side of the cover (110), and an outer electrode terminal (112) located on the outer side of the cover (110), wherein the inner electrode terminal (109) and the outer electrode terminal (112) are electrically connected via a current interruption device, characterized in that the current interruption device is the current interruption device according to claim 3, the outer electrode terminal (112) is electrically connected to the flip member (102), and the notched member (101) is electrically connected to the inner electrode terminal (109). 5. The battery cover plate assembly according to claim 4, characterized in that a support ring (113) is sealed between the lower side of the outer periphery of the flip member (102) and the cover plate (110), and the outer periphery of the electrode external terminal (112) is electrically connected to the upper side of the outer periphery of the flip member (102). 6. The battery cover assembly according to claim 5, characterized in that a support flange (114) is formed on the inner wall of the support ring (113), and the outer peripheral edges of the flip member (102) and the electrode outer terminal (112) are supported on the upper surface of the support flange (114). 7. A single battery, comprising a housing (111), a battery cell contained in the housing (111), and a battery cover assembly encapsulating the housing (111), characterized in that the battery cover assembly is the battery cover assembly according to claim 5 or 6, the inner electrode terminal (109) is electrically connected to the battery cell, and the flip member (102) is in communication with the internal gas of the housing (111). 8. A battery module, characterized in that the single battery according to claim 7 is arranged in the battery module. 9. A power battery, comprising a housing and a battery module arranged in the housing, wherein the battery module is the battery module according to claim 8. 10. An electric vehicle, characterized in that the electric vehicle is provided with the power battery according to claim 9.