CN219801223U - Electrode terminal, secondary battery, battery pack, and vehicle - Google Patents

Abstract

The disclosure relates to the technical field of vehicles, in particular to an electrode terminal, a secondary battery, a battery pack and a vehicle. The electrode terminal is used for being connected with the electrode lug to output electric energy, the electrode terminal comprises a terminal plate and a electrode post, the electrode post penetrates through the electrode leading-out hole, and one end of the electrode post is connected with the electrode lug; the terminal plate comprises an extension part, the terminal plate covers the electrode leading-out hole and is connected with the pole, and the extension part extends to the top surface vertical to the height direction Z of the shell and is used for being connected with the bus bar. The secondary battery top surface is extended to the secondary battery through the extension part, and the secondary battery can be welded from the secondary battery top surface when the system is connected in series or in parallel, so that the secondary battery is assembled into a box body first, then the top surface is welded through the extension part, and the influence on the product quality caused by transfer after welding is avoided.

Description

Electrode terminal, secondary battery, battery pack, and vehicle

Technical Field

The disclosure relates to the technical field of vehicles, in particular to an electrode terminal, a secondary battery, a battery pack and a vehicle.

Background

The power battery is also called a secondary battery, and is a rechargeable battery. Power batteries are widely used, for example, low-capacity power batteries may be used for small electric vehicles, and high-capacity power batteries may be used for large electric vehicles. The power battery includes a case having a receiving cavity and a secondary battery disposed in the case. The case may be provided with functional parts such as electrode terminals, which are generally connected with tabs in the electrode assembly through tabs to form a current loop.

In the conventional secondary battery, electrode terminals are provided at both sides of the secondary battery, and this arrangement results in the need to externally weld the secondary battery in series or in parallel when the battery pack is assembled and welded, and then integrally move into the case, thus easily causing quality problems in the welded product during the transfer process.

Disclosure of Invention

In order to solve the above technical problems, the present disclosure provides an electrode terminal, a secondary battery, a battery pack, and a vehicle.

The first aspect of the present disclosure provides an electrode terminal for connection with a tab to output electric energy, the electrode terminal including a terminal plate and a post, the post being disposed through an electrode lead-out hole, one end of the post being connected with the tab;

the terminal plate comprises an extension portion, the terminal plate covers the electrode leading-out hole and is connected with the pole, and the extension portion extends to the top surface of the shell in the height direction Z and is used for being connected with the bus bar.

Further, the terminal plate further comprises a fixing portion and a bending portion, the bending portion is connected with the fixing portion and the extending portion respectively, the extending portion is bent relative to the fixing portion, the fixing portion covers the electrode leading-out hole and is connected with the pole, and the extending portion covers the top face of the shell in the height direction Z.

A second aspect of the present disclosure provides a secondary battery, comprising:

a housing having a receiving chamber, the housing including a side surface perpendicular to a housing width direction Y, the side surface being provided with an electrode lead-out hole near an end of the housing in a length direction X;

the electrode assembly is arranged in the accommodating cavity and comprises two opposite end faces and electrode lugs extending out from each end face, the two end faces are perpendicular to the length direction X of the shell, and the electrode lugs are arranged corresponding to the electrode leading-out holes;

an electrode terminal according to the first aspect.

Further, the terminal plate includes a fixing portion, a bending portion and an extending portion, the bending portion is connected with the fixing portion and the extending portion respectively, the extending portion is bent relative to the fixing portion, the fixing portion covers the electrode lead-out hole and is connected with the pole, and the extending portion covers the top surface of the shell in the height direction Z.

Further, the top surface is formed with a first recess portion, the first recess portion extends to the side surface, and the extension portion is disposed in the first recess portion.

Further, a second concave part is formed on the side surface, the second concave part is communicated with the first concave part, the electrode extraction hole is extracted from the second concave part, and the fixing part is arranged on the second concave part.

Further, a fixing piece is arranged between the terminal plate and the shell.

Further, along the height direction Z of the shell, the top height of the fixing piece is not higher than the height of the top surface.

Further, the secondary battery further includes an insulating member covering the fixing portion;

the insulating piece is matched with the fixing piece in a clamping way.

Further, the housing has two sides and a facet connecting the two sides, the area of the sides is larger than the area of the facet, and one of the sides is a cover plate for covering the accommodating cavity;

the two side surfaces are arranged at intervals along the width direction Y of the shell, and the two small surfaces are arranged at intervals along the height direction Z of the shell.

A third aspect of the present disclosure provides a battery pack including the secondary battery of the second aspect.

A fourth aspect of the present disclosure provides a vehicle comprising the battery pack of the third aspect.

Compared with the prior art, the technical scheme provided by the embodiment of the disclosure has the following advantages:

in the electrode terminal provided by the embodiment of the disclosure, the terminal plate includes an extension portion, the terminal plate covers the electrode lead-out hole and is connected with the post, and the extension portion extends to the top surface of the housing in the height direction for connection with the bus bar. According to the embodiment of the disclosure, the extension part extends to the top surface of the secondary battery, and the structure is arranged so that the secondary battery can be welded from the top surface of the secondary battery when the systems are welded in series or in parallel, so that the secondary battery is assembled into the box body first, then the top surface is welded through the extension part, and the influence on the product quality caused by transfer after welding is avoided.

Drawings

Fig. 1 is a schematic structural view of a secondary battery provided in an embodiment of the present disclosure;

fig. 2 is an exploded view of a secondary battery provided by an embodiment of the present disclosure;

fig. 3 is a schematic structural view of the positive electrode output terminal;

fig. 4 is an exploded view of the positive output terminal;

fig. 5 is a schematic structural view of the negative output terminal;

fig. 6 is an exploded view of the negative output terminal;

fig. 7 is an assembly schematic view of a secondary battery provided by an embodiment of the present disclosure;

fig. 8 is another structural schematic view of a secondary battery provided by an embodiment of the present disclosure;

fig. 9 is another structural schematic view of an electrode terminal;

fig. 10 is another structural schematic view of an electrode terminal;

fig. 11 is a schematic structural view of an installation position of an explosion-proof valve in a secondary battery according to an embodiment of the present disclosure;

fig. 12 is a schematic view of a plurality of secondary batteries grouped;

fig. 13 is a schematic view of an external structure of a secondary battery provided in an embodiment of the present disclosure.

Reference numerals: 1. a secondary battery; 2. a housing; 3. an electrode assembly; 4. a cover plate; 41. a liquid injection hole; 21. a first side; 22. a second side; 23. a third side; 24. a fourth side; 25. a positive electrode terminal; 26. a negative electrode terminal; 27. an explosion-proof valve; 251. a positive electrode post; 252. a positive electrode aluminum block; 2521. a positive electrode extension; 2522. a positive electrode bending portion; 2523. a positive electrode fixing portion; 253. positive electrode plastic cement; 2531. a positive electrode plastic first side wall; 2532. a positive plastic clamping hole; 254. a positive electrode first concave portion; 255. a positive electrode second concave portion; 256. an anode insulating cover; 2561. positive electrode insulating cover salient points; 2562. an arc edge of the positive electrode insulating cover; 2563. the top surface of the positive electrode insulating cover; 2564. the side surface of the positive electrode insulating cover; 261. a negative electrode column; 262. a negative electrode aluminum block; 2621. a negative electrode extension; 2622. a negative electrode bending portion; 2623. a negative electrode fixing portion; 263. negative electrode plastic cement; 2631. a negative electrode plastic first side wall; 2632. a negative plastic clamping hole; 264. a negative electrode first concave portion; 265. a negative electrode second concave portion; 266. a negative electrode insulating cover; 2661. a negative electrode insulating cap bump; 2662. arc edges of the negative electrode insulating cover; 2663. a top surface of the negative electrode insulating cover; 2664. the side of the negative electrode insulating cover.

Detailed Description

In order that the above objects, features and advantages of the present disclosure may be more clearly understood, a further description of aspects of the present disclosure will be provided below. It should be noted that, without conflict, the embodiments of the present disclosure and features in the embodiments may be combined with each other.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure, but the present disclosure may be practiced otherwise than as described herein; it will be apparent that the embodiments in the specification are only some, but not all, embodiments of the disclosure.

In the conventional secondary battery, electrode terminals are provided at both sides of the secondary battery, and when the secondary battery is assembled and welded, the secondary battery is required to be welded in series outside, and then integrally moved into a case, so that problems are easily caused in the transfer process. Based on this, the embodiment of the disclosure provides a secondary battery, and the secondary battery terminal extends to the upper portion of the secondary battery from the two ends of the battery, so that the secondary battery can be welded from the upper end of the secondary battery when the systems are welded in series or in parallel, the assembly welding sequence of the secondary batteries can be optimized, the secondary batteries are assembled into a box body and then welded, the assembly difficulty of the system is reduced, and the influence on the product quality caused by transfer after welding can be avoided.

As shown in fig. 1 and 2, an electrode terminal provided in an embodiment of the present disclosure is configured to be connected to a tab to output electric energy, where the electrode terminal includes a terminal plate and a post, the post is disposed through an electrode lead hole, and one end of the post is connected to the tab; the terminal plate comprises an extension part, the terminal plate covers the electrode leading-out hole and is connected with the pole, and the extension part extends to the top surface of the shell 2 in the height direction Z and is used for being connected with the busbar. According to the embodiment of the disclosure, the extension part extends to the top surface of the secondary battery, and the structure is arranged so that the secondary battery can be welded from the top surface of the secondary battery when the systems are welded in series or in parallel, so that the secondary battery is assembled into the box body first, then the top surface is welded through the extension part, and the influence on the product quality caused by transfer after welding is avoided.

As shown in fig. 1 and 2, a secondary battery 1 provided by an embodiment of the present disclosure includes a case 2, an electrode assembly 3, and electrode terminals. The case 2 has a receiving chamber in which the electrode assembly 3 is disposed. The case 2 includes an opening, and a receiving chamber for receiving the electrode assembly 3 and the electrolyte. The housing 2 may be made of a material such as aluminum, an aluminum alloy, or plastic. The battery electrolyte filling device further comprises a cover plate 4, wherein the cover plate 4 is used for covering the opening, and the cover plate 4 is integrally provided with a structure of a liquid filling hole 41 for filling electrolyte after battery sealing.

The casing 2 includes the side of perpendicular to casing 2 width direction Y, and the side is equipped with the electrode and draws the hole, and the electrode draws the hole and set up to two, and two electrode draw the hole and can be located perpendicular to casing 2 width direction Y two opposite sides respectively, and two electrode draw the hole and also can be located same side.

The electrode lead-out hole is close to the end part of the shell 2 in the length direction X; the electrode assembly 3 includes two opposite end faces and tabs extending from each end face, two tabs, i.e., a positive tab and a negative tab. Both end faces are perpendicular to the length direction X of the shell 2, and the electrode lugs and the electrode lead-out holes are correspondingly arranged.

The electrode terminals are used for being connected with the electrode lugs so as to output electric energy. The electrode terminals are positive electrode terminals 25 or negative electrode terminals 26. The electrode terminal comprises a terminal plate and a pole post, the pole post penetrates through the electrode leading-out hole, and one end of the pole post is connected with the pole lug. The posts include a positive post 251 and a negative post 261.

The terminal plate comprises an extension part, the terminal plate covers the electrode leading-out hole and is connected with the pole, and the extension part extends to the top surface of the shell 2 in the height direction Z and is used for being connected with the busbar. The terminal plate may be an aluminum block. According to the embodiment of the disclosure, the extension part extends to the top surface of the secondary battery 1, so that the secondary battery 1 is welded from the top surface of the secondary battery 1 when the system is connected in series or in parallel, the operation is convenient, the assembly and welding sequence of the secondary battery 1 can be optimized, the secondary battery 1 is assembled into a box body in a group and then welded, the assembly difficulty of the system is reduced, and the influence on the product quality caused by transfer after welding can be avoided.

The terminal board includes fixed part, bending portion and extension, and bending portion is connected with fixed part and extension respectively, and the extension is bent for fixed part, and fixed part covers the electrode and draws forth the hole and be connected with the utmost point post, and the extension covers the top surface of casing 2 direction of height Z. Through the extension portion bending, the top surface of casing 2 is covered to the extension portion for the battery can be followed secondary cell 1 top surface and welded when system series connection or parallelly connected welding, convenient operation can optimize secondary cell 1 and assemble welding order in groups, makes secondary cell 1 assemble earlier and pack into the box after welding, reduces the assembly degree of difficulty of system, also can avoid transferring after the welding and influence product quality.

As shown in fig. 1, 2, 3, 4, 5 and 6, the secondary battery 1 provided by the present utility model includes a first side 21, a second side 22, a third side 23 and a fourth side 24, wherein the second side 22 is a top surface. The first side 21 is located in the front of the secondary battery 1, the two ends of the Z-direction top of the first side are provided with a positive electrode terminal 25 and a negative electrode terminal 26, the two poles extend to the second side 22, and the third side 23 and the fourth side 24 are respectively provided with an explosion-proof valve 27. On top of the third side 23 and the fourth side 24 are insulation portions of a positive electrode terminal 25 and a negative electrode terminal 26.

As shown in fig. 12, the positive electrode terminal 25 and the negative electrode terminal 26 are located on two edges of the case 2 in the Y direction at the top in the Z direction, and the positive electrode terminal 25 and the negative electrode terminal 26 are located on the first side 2121 at the center in the Y direction thickness direction, and are bent upward to extend to the second side 22.

In some embodiments, the top surface is formed with a first recess portion, the first recess portion extends to the side surface, the top surface is stepped, and the extension portion is disposed in the first recess portion. The first concave part can give more installation space for the extension part, thereby being beneficial to improving the structural compactness when the pole is matched with an external part for use.

In some specific embodiments, the side is formed with the second depressed part, and second depressed part and first depressed part intercommunication, and the second depressed part can let more installation space for the fixed part, and the electrode draws forth the hole from the second depressed part, and the fixed part sets up in the second depressed part, is favorable to improving the compactibility when utmost point post and external part cooperation use.

In some embodiments, a fixing member is provided between the terminal plate and the housing 2. The fixing piece can be plastic and can play a role in supporting and fixing the polar post. When the fixing member is insulating plastic, the safety of the secondary battery 1 can be improved.

In some specific embodiments, along the height direction Z of the housing 2, the top of the fixing member is not higher than the top surface, so that the compactness of the assembled secondary battery 1 can be improved, and the additional occupation of the Z-direction space can be avoided.

In some specific embodiments, the secondary battery 1 further includes an insulating member covering the fixing portion; the insulator is engaged with the fixing member, so that the safety of the secondary battery 1 can be improved. The insulating member may be an insulating cover.

As shown in fig. 3 and 4, the positive electrode terminal 25 is inlaid in the first recess and the second recess at the corners of the first side 21, the second side 22 and the third side 23 on the case 2, the positive electrode terminal 25 is composed of four parts including a positive electrode post 251, a positive electrode terminal plate 252, a positive electrode plastic 253 and a positive electrode insulating cover 256, the positive electrode post 251 is led out from the inside of the case 2, and is connected with the electrode assembly or the winding core through a conductive member. The positive terminal plate 252 includes a positive electrode fixing portion 2523, a positive electrode bent portion 2522, and a negative electrode extending portion 2521. The positive terminal plate may be an aluminum block. The positive pole 251 and the positive pole aluminum block 252 are fixed and kept in effective electrical connection through riveting, welding and other schemes, the positive pole extension portion 2521 of the positive pole aluminum block 252 extends upwards to the second side face 22 in a bending mode, positive pole plastic 253 is wrapped outside the positive pole 251, and the positive pole plastic 253 is inlaid at the first concave portion and the second concave portion of the corner of the shell 2, which are described above. The positive plastic first side wall 2531 is not higher than the third side surface 23. Positive electrode terminal 25 forms positive electrode first concave part 254 after the assembly, and this first concave part can hold the system's the piece that converges when electric core welds in groups for the system's the piece that converges does not surpass second side 22, makes the system's the piece that converges not surpass the top surface, promotes the space utilization of battery at the system. The positive electrode terminal 25 is assembled to form a positive electrode second concave portion 255 for accommodating a positive electrode insulating cover 256 for insulation protection. The positive electrode insulating cover 256 includes a positive electrode insulating cover top surface 2563 and a positive electrode insulating cover side surface 2564. The positive electrode insulating cover 256 is provided with a positive electrode insulating cover arc edge 2562, the structure is in limit fit with the positive electrode bending portion 2522, and the positive electrode insulating cover protruding point 2561 is in clamping fit with the positive electrode plastic clamping hole 2532.

As shown in fig. 5 and 6, the negative electrode terminal 26 is inlaid in the first concave portion and the second concave portion at the corners of the first side 21, the second side 22 and the fourth side 24 on the casing 2, the negative electrode terminal 26 is composed of four parts including a negative electrode post 261, a negative electrode terminal plate 262, a negative electrode plastic 263 and a negative electrode insulating cover 266, the negative electrode post 261 is led out from the inside of the casing 2, and is connected with a motor assembly or a winding core through a conductive part. The negative terminal plate 262 includes a negative fixing portion 2623, a negative bent portion 2622, and a negative extending portion 2621. The negative terminal plate 262 may be an aluminum block. The negative pole post 261 and the negative pole aluminum block 262 are fixed and keep effective electric connection through riveting, welding and other schemes, the negative pole extension portion 2621 of the negative pole aluminum block 262 extends upwards to the second side face 22 in a bending mode, negative pole plastic 263 wraps the negative pole post 261, and the negative pole plastic 263 is inlaid in the first concave portion and the second concave portion of the corner of the shell 2 described above. The negative plastic first side 2631 is no higher than the fourth side 24. The negative electrode terminal 26 is assembled to form a negative electrode first recess 264, which can accommodate the system bus bar when the battery cells are welded in groups, so that the system bus bar does not exceed the second side 22 of the secondary battery 1, that is, the system bus bar does not exceed the top surface of the case 2, and the space utilization of the secondary battery 1 in the system is improved. The negative electrode terminal 26 is assembled to form a negative electrode second recess 265 which is adapted to receive a negative electrode insulating cover 266 for insulation protection. The negative insulation cover 266 includes a negative insulation cover top face 2663 and a negative insulation cover side face 2664.

The negative insulating cap 266 is provided with a negative insulating cap arcuate edge 2662 which is in a positive fit with the negative bent portion 2622, and the negative insulating cap protruding point 2661 is in a positive fit with the negative plastic clamping hole 2632.

Fig. 9 and 10 provide a complementary scheme of the electrode post arrangement of the secondary battery 1, here taking the arrangement scheme of the negative electrode terminals 26 as an example, the arrangement of the positive electrode terminals 25 is symmetrically arranged with the negative electrode terminals 26, and the details are as follows:

as shown in fig. 9, the second side 22 is not recessed, and the corner extension of the negative electrode terminal 26 is attached to the surface of the second side 22 and protrudes from the second side 22.

As shown in fig. 10, the pole is embedded in the corners of the second side 22, the third side 23 and the fourth side 24, and the main body is located in the second side 22 and does not bend and extend toward the third side 23.

As shown in FIG. 11, different arrangement positions of the explosion-proof valves 27 are provided, the explosion-proof valves 27 designed for the secondary battery 1 can be circumferentially arranged along the illustrated positions, and the number of the explosion-proof valves 27 is equal to or greater than 1, and the arrangement is carried out according to actual requirements.

As shown in fig. 12, a group arrangement manner of the secondary batteries 1 to which the present embodiment is applied is provided, since the positive electrode terminal 25 and the negative electrode terminal 26 are arranged at the intermediate position in the thickness direction Y of the battery case 2, the system series arrangement demand can be satisfied, and the battery cells can ensure the uniformity of the pole pitch of the adjacent secondary batteries 1 when the battery cells are arranged at intervals upside down.

As shown in fig. 7, the housing 2 has two sides and a facet connecting the two sides, as shown in fig. 13, the side is a first side 2121, the facet is a second side 2222, and the sides and the facet are alternately arranged.

The area of one side is larger than that of the small surface, and one side is a cover plate 4 for covering the accommodating cavity; the two side surfaces are arranged at intervals along the width direction Y of the housing 2, and the two facets are arranged at intervals along the height direction Z of the housing 2. By adopting the embodiment of the disclosure, the scheme of opening the side surface of the battery can be adopted, so that the difficulty of inserting the electrode assembly 3 or the winding core into the shell is reduced; because the side surface area is large and the side surface is open, the distance of the winding core entering the shell is short, the fit clearance between the winding core and the shell 2 can be shortened, and the energy density of the product is improved;

alternatively, the electrode assembly 3 is a flat structure having two broad faces and two narrow faces connecting the two broad faces, the broad faces and the narrow faces of the electrode assembly 3 being alternately disposed. The area of the broad face is larger than the area of the narrow face. The wide surface of the electrode assembly 3 corresponds to the side surface of the case 2, and the narrow surface of the electrode assembly 3 corresponds to the small surface of the case 2.

Alternatively, the number of electrode assemblies 3 is two. The two sets of electrode assemblies 3 are stacked in the Y direction.

Alternatively, the number of electrode assemblies 3 is plural. The plurality of sets of electrode assemblies 3 are stacked in the Y direction.

As shown in fig. 7, fig. 7 provides an assembly scheme of the secondary battery 1 shown in the present disclosure, the electrode assembly 3 or the winding core is first pre-welded and shaped to cut the tabs on both sides, then the tabs are inserted into the case, the tabs are laser welded with the connecting pieces inside the case 2, the cover plate 4 is safely mounted on the case 2, and the case 2 is welded and sealed with the top cover.

As shown in fig. 8, the positive electrode terminal 25 and the negative electrode terminal 26 may be arranged at a desired height downward in the Z direction of the case 2 of the secondary battery 1 according to the assembly connection requirements of the system.

The battery pack provided by the embodiment of the present disclosure includes the secondary battery 1 provided by the embodiment of the present disclosure. The secondary battery 1 is housed in a case. The case is used to provide an accommodating space for the secondary battery 1, and may have various structures, such as a cylinder, a rectangular parallelepiped, and the like. As shown in fig. 13, in the battery pack, the plurality of secondary batteries 1 may be provided, and the plurality of secondary batteries 1 may be connected in series or in parallel, and the series-parallel connection means that the plurality of secondary batteries 1 are connected in both series and parallel. The secondary batteries 1 can be directly connected in series or in parallel or in series-parallel, and then the whole body formed by the secondary batteries 1 is accommodated in the box body; of course, a plurality of secondary batteries 1 may be connected in series or parallel or series-parallel to form a battery module, and then a plurality of battery modules may be connected in series or parallel or series-parallel to form a whole and be accommodated in the case.

The vehicle provided by the embodiments of the present disclosure includes the secondary battery 1 provided by the embodiments of the present disclosure or includes the battery pack provided inside the implementations of the present disclosure. The vehicle can be a fuel oil vehicle, a fuel gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended vehicle and the like. The interior of the vehicle is provided with a secondary battery 1, and the secondary battery 1 may be provided at the bottom or at the head or at the tail of the vehicle. The secondary battery 1 may be used for power supply of a vehicle, for example, the secondary battery 1 may serve as an operating power source of the vehicle. The vehicle may further include a controller for controlling the secondary battery 1 to supply power to the motor, for example, for operation power demand at the time of starting, navigation, and running of the vehicle, and a motor.

In some specific embodiments, the secondary battery 1 may be used not only as an operating power source of a vehicle but also as a driving power source of the vehicle, instead of or in part instead of fuel oil or natural gas, to supply driving power to the vehicle.

It should be noted that in this document, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises an element.

Claims (11)

1. An electrode terminal for connecting with a tab to output electric energy, wherein the electrode terminal comprises a terminal plate and a pole, the pole is arranged in an electrode lead-out hole in a penetrating way, and one end of the pole is connected with the tab;

the terminal plate comprises an extension part, the terminal plate covers the electrode leading-out hole and is connected with the pole, and the extension part extends to the top surface of the shell in the height direction (Z) and is used for being connected with the busbar.

2. The electrode terminal according to claim 1, wherein the terminal plate further includes a fixing portion and a bending portion, the bending portion being connected to the fixing portion and the extending portion, respectively, the extending portion being bent with respect to the fixing portion, the fixing portion covering the electrode lead-out hole and being connected to the post, the extending portion covering a top surface of the case in a height direction (Z).

3. A secondary battery, characterized by comprising:

a housing having a receiving chamber, the housing including a side surface perpendicular to the housing width direction (Y), the side surface being provided with an electrode lead-out hole near an end of the housing in the length direction (X);

the electrode assembly is arranged in the accommodating cavity and comprises two opposite end faces and electrode lugs extending out from each end face, the two end faces are perpendicular to the length direction (X) of the shell, and the electrode lugs and the electrode leading-out holes are correspondingly arranged;

an electrode terminal according to claim 1 or 2.

4. The secondary battery according to claim 3, wherein the top surface is formed with a first concave portion extending to the side surface, the extension portion being provided in the first concave portion.

5. The secondary battery according to claim 4, wherein the side surface is formed with a second concave portion that communicates with the first concave portion, the electrode lead-out hole is led out from the second concave portion, and a fixing portion is provided in the second concave portion.

6. The secondary battery according to claim 3, wherein a fixing member is provided between the terminal plate and the case.

7. The secondary battery according to claim 6, wherein a top height of the fixing member is not higher than a height of the top surface in the case height direction (Z).

8. The secondary battery according to claim 7, further comprising an insulating member that covers the fixing portion;

the insulating piece is matched with the fixing piece in a clamping way.

9. The secondary battery according to any one of claims 3 to 8, wherein the case has two sides and a facet connecting the two sides, an area of the sides being larger than an area of the facet, one of the sides being a cover plate for covering the accommodation chamber;

the two side surfaces are arranged at intervals along the width direction (Y) of the shell, and the two small surfaces are arranged at intervals along the height direction (Z) of the shell.

10. A battery pack comprising the secondary battery according to any one of claims 3 to 9.

11. A vehicle comprising the battery pack of claim 10.