CN113036201B

CN113036201B - Electrochemical cell

Info

Publication number: CN113036201B
Application number: CN202011507234.7A
Authority: CN
Inventors: 李虎; 梅武; 赵宇峰; 孙流莉
Original assignee: Changchun Lvdong Hydrogen Energy Technology Co ltd
Current assignee: Changchun Lvdong Hydrogen Energy Technology Co ltd
Priority date: 2020-12-18
Filing date: 2020-12-18
Publication date: 2022-08-02
Anticipated expiration: 2040-12-18
Also published as: CN113036201A

Abstract

The invention discloses an electrochemical cell, which comprises a cell component, an inner upper end plate, an inner lower end plate and a first connecting piece, outer upper end plate, outer lower end plate, the second connecting piece, middle upper end plate and middle lower end plate, interior upper end plate and interior lower end plate are relative each other and the interval sets up along the direction of height each other, interior upper end plate and interior lower end plate are connected through first connecting piece, battery pack is by the centre gripping between upper end plate and interior lower end plate including, outer upper end plate and outer lower end plate are relative each other and the interval sets up along the direction of height each other, outer upper end plate and outer lower end plate pass through the second connecting piece and connect, interior upper end plate and interior lower end plate are by the centre gripping between outer upper end plate and outer lower end plate, middle upper end plate is established between upper end plate and outer upper end plate including, middle lower end plate is established between lower end plate and the outer lower end plate including, middle upper end plate and middle lower end plate thickness increases towards the center from all around. The electrochemical cell provided by the embodiment of the invention has the advantages of simple structure, high working efficiency of the cell component and the like.

Description

Electrochemical cell

Technical Field

The present invention relates to the field of fuel cells, and in particular, to an electrochemical cell.

Background

In the related art, the electrochemical cell stack is usually pressed by bolts disposed around the end plates to fasten the conductive plates, the sealing gaskets, the bipolar plates, the membrane electrode assemblies, and other components inside the cell. The inventor of the application finds that when the stack is assembled by fastening bolts on the periphery of the end plate, the central area of the end plate is generally subjected to large deformation, warping and the like, so that the problem of center decompression of the membrane electrode assembly is caused, poor contact and ohmic loss between the central active area of the membrane electrode assembly and adjacent components are caused to rise, and the performance and efficiency of the stack are reduced.

In the related technology, the top plate and the bottom plate of the chemical battery are connected by bolts, a cavity is enclosed between the top plate and the bipolar plate, and the cavity is filled with the generated high-pressure hydrogen so as to achieve the purposes of uniformly pressurizing the bipolar plate and preventing the center from warping under the high-pressure working condition.

Or a bolt is screwed at the center of the end plate, and the warping of the central part is restrained, so that the pressure loss of the central active area under the high-pressure working condition is avoided, but the tearing of the end plate or the strain degree of the end plate is easily caused, and the service life of the whole body is further influenced.

Or the end plate of the chemical battery is directly restrained by a large number of restraining elements so as to achieve the purpose of reducing the deformation of the center of the end plate, but the resource use is large, and the deformation of the center of the end plate is still difficult to inhibit along with the increase of the active area.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.

To this end, embodiments of the present invention provide an electrochemical cell.

An electrochemical cell according to an embodiment of the present invention includes:

a battery assembly;

the battery pack comprises an inner upper end plate and an inner lower end plate, wherein the inner upper end plate and the inner lower end plate are opposite to each other and arranged at intervals along the height direction of the battery pack;

the outer upper end plate and the outer lower end plate are opposite to each other and arranged at intervals along the height direction of the battery assembly, the outer upper end plate and the outer lower end plate are connected through a second connecting piece, and the inner upper end plate and the inner lower end plate are clamped between the outer upper end plate and the outer lower end plate;

middle upper end plate and middle lower end plate, middle upper end plate is established interior upper end plate with between the outer upper end plate, middle lower end plate is established interior lower end plate with between the outer lower end plate, the thickness of middle upper end plate increases towards the center from all around, the thickness of middle lower end plate increases towards the center from all around.

The electrochemical cell provided by the embodiment of the invention has the advantages of simple structure and high working efficiency of the cell assembly.

In some embodiments, the thickness of the intermediate upper plate increases from the periphery towards the center, and the thickness of the intermediate lower plate increases from the periphery towards the center.

In some embodiments, the thickness of the intermediate upper end plate increases in a step-like manner from the periphery toward the center, and the thickness of the intermediate lower end plate increases in a step-like manner from the periphery toward the center.

In some embodiments, the steps are multi-step.

In some embodiments, the middle upper end plate is close to the surface of interior upper end plate is the plane, middle upper end plate is kept away from the surface of interior upper end plate is ladder face or arcwall face, middle lower end plate is close to the surface of interior lower end plate is the plane, middle upper end plate is kept away from the surface of interior lower end plate is ladder face or arcwall face.

In some embodiments, the length of the inner upper end plate and the inner lower end plate in the length direction of the battery assembly is greater than the width of the outer upper end plate and the outer lower end plate in the length direction of the battery assembly and greater than the length of the battery assembly;

the inner upper end plate and the inner lower end plate are respectively provided with a first through hole at two ends in the length direction of the battery pack, the first end of the first connecting piece penetrates through the first through hole in the inner upper end plate, and the second end of the first connecting piece penetrates through the first through hole in the inner lower end plate.

In some embodiments, the length of the outer upper end plate and the outer lower end plate in the battery module width direction is greater than the width of the inner upper end plate and the inner lower end plate in the battery module width direction and greater than the width of the battery module;

outer upper end plate with outer lower end plate is in battery pack's the ascending both ends of width direction are equipped with the second through-hole respectively, outer upper end plate with outer lower end plate passes through the second connecting piece and connects, the first end of second connecting piece passes second through-hole on the outer upper end plate, the second end of second connecting piece passes second through-hole on the outer lower end plate.

In some embodiments, the battery assembly includes a plurality of unit cells, a first conductive plate, and a second conductive plate, the unit cells are stacked in a height direction of the battery assembly and clamped between the first conductive plate and the second conductive plate, a plurality of first vent holes are respectively formed at two ends of the unit cells in a length direction of the battery assembly, the first vent holes extend in the height direction of the battery assembly, the first vent holes are arranged in a width direction of the battery assembly at intervals, and second vent holes aligned with the first vent holes are formed in the inner upper end plate and the inner lower end plate.

In some embodiments, the length of the middle upper end plate and the middle lower end plate in the length direction of the battery assembly is equal to the width of the outer upper end plate and the outer lower end plate in the length direction of the battery assembly, and the width of the middle upper end plate and the middle lower end plate in the width direction of the battery assembly is equal to the width of the inner upper end plate and the inner lower end plate in the width direction of the battery assembly.

In some embodiments, the first connecting members and the second connecting members are a plurality of connecting members, the plurality of first connecting members are arranged at intervals along the width direction of the battery assembly, the plurality of second connecting members are arranged at intervals along the length direction of the battery assembly, and the first connecting members and the second connecting members are bolts.

Drawings

Fig. 1 is a schematic diagram of the structure of an electrochemical cell according to an embodiment of the present invention.

Fig. 2 is a schematic structural view of a first end plate group, a second end plate group and a third end plate group according to an embodiment of the invention.

Fig. 3 is a structural schematic view of a second end plate according to an embodiment of the present invention.

Fig. 4 is a cross-sectional view of a second end plate according to an embodiment of the invention.

Fig. 5 is a schematic view of yet another structure of a second end plate according to an embodiment of the invention.

Fig. 6 is a cross-sectional view of yet another structure of a second end plate according to an embodiment of the present invention.

Reference numerals:

the electrochemical cell (100) is provided with,

battery assembly 1, cell 101, first conductive plate 102, second conductive plate 103,

interior upper end plate 2, interior bottom end plate 3, outer top end plate 4, outer bottom end plate 5, middle top end plate 6, first through-hole 7, second through-hole 8, second through-hole 9, first connecting piece 10, second connecting piece 11.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

As shown in fig. 1 to 6, an electrochemical cell 100 according to an embodiment of the present invention includes a cell assembly 1, an inner upper end plate 2, an inner lower end plate 3, a first connecting member 10, an outer upper end plate 4, an outer lower end plate 5, a second connecting member 11, an intermediate upper end plate 6, and an intermediate lower end plate (not shown).

The inner upper end plate 2 and the inner lower end plate 3 are disposed opposite to and spaced apart from each other in the height direction (the up-down direction shown in fig. 1) of the battery assembly 1, the inner upper end plate 2 and the inner lower end plate 3 are connected by a first connecting member 10, and the battery assembly 1 is held between the inner upper end plate 2 and the inner lower end plate 3.

Outer upper end plate 4 and outer lower end plate 5 are relative each other and the interval sets up along battery pack 1's direction of height, and outer upper end plate 4 and outer lower end plate 5 pass through second connecting piece 11 to be connected, and interior upper end plate 2 and interior lower end plate 3 are by the centre gripping between outer upper end plate 4 and outer lower end plate 5.

The middle upper end plate 6 is arranged between the inner upper end plate 2 and the outer upper end plate 4, the middle lower end plate is arranged between the inner lower end plate 3 and the outer lower end plate 5, the thickness of the middle upper end plate 6 (the length of the middle upper end plate 6 in the vertical direction in fig. 1) is increased from the periphery to the center, and the thickness of the middle lower end plate is increased from the periphery to the center.

As shown in fig. 1, the battery assembly 1 is sandwiched between an inner upper end plate 2 and an inner lower end plate 3 to primarily confine and fix the battery assembly 1 in the up-down direction by the inner upper end plate 2 and the inner lower end plate 3. The clamping force of the inner upper end plate 2 and the outer upper end plate 4 to the battery assembly 1 can be adjusted by the first connecting member 10, and the stronger the clamping force is, the more stable the connection between the battery assembly 1 and the inner upper end plate 2 and the inner lower end plate 3 is.

The inner upper end plate 2 and the inner lower end plate 3 may be further defined by the outer upper end plate 4 and the outer lower end plate 5 to secondarily define and fix the battery assembly 1. The clamping force of the outer upper end plate 4 and the outer lower end plate 5 on the inner upper end plate 2 and the inner lower end plate 3 is adjusted by adjusting the second connecting piece 11 so as to strengthen the clamping force of the inner upper end plate 2 and the inner lower end plate 3 on the battery pack 1, and further the overall stability is enhanced. The first connecting member 10 and the second connecting member 11 may be elastic members, such as rubber bands, springs, and the like, and may also be bolts.

As shown in fig. 1 and 2, an intermediate upper end plate 6 is disposed between the outer upper end plate 4 and the inner upper end plate 2, and the thickness of the intermediate upper end plate 6 increases from the periphery of the intermediate upper end plate 6 to the center of the intermediate upper end plate 6, and when the outer upper end plate 4 clamps the inner upper end plate 2 by the restraining force generated by the second connecting member 11, the intermediate upper end plate 6 first receives the pressing force from the outer upper end plate 4, and the intermediate upper end plate 6 generates a pressing force on the upper end of the inner upper end plate 2, so that the inner upper end plate 2 can be sufficiently contacted with the battery pack 1. It can be understood that the inner lower end plate 3 can be sufficiently contacted with the lower end of the battery assembly 1 through the middle lower end plate, and the problem of performance degradation caused by poor contact between the inner upper end plate 2 and the inner lower end plate 3 and the battery assembly 1 is effectively avoided.

According to the electrochemical cell 100 provided by the embodiment of the invention, through the matching of the inner upper end plate 2, the inner lower end plate 3, the first connecting piece 10, the outer upper end plate 4, the outer lower end plate 5, the second connecting piece 11, the middle upper end plate 6 and the middle lower end plate, the structure is simple, the operation is convenient, the contact area between the inner upper end plate 2 and the contact surface film at the upper end of the cell assembly 1 and between the inner lower end plate 3 and the lower end of the cell assembly 1 can be enhanced, the poor contact of the cell assembly 1 is avoided, and the overall efficiency of the electrochemical cell 100 is stable. It is understood that the first and second connecting

members

10 and 11 may further define and provide some protection to the battery assembly 1 in the front-to-rear direction and/or the left-to-right direction as shown in fig. 1.

Therefore, the electrochemical cell 100 according to the embodiment of the present invention has advantages of simple structure, high operation efficiency of the cell assembly 1, and the like.

In some embodiments, the thickness of the intermediate upper end plate 6 increases from the periphery towards the center, and the thickness of the intermediate lower end plate increases from the periphery towards the center.

According to the electrochemical cell 100 of the embodiment of the present invention, since the thickness of the middle upper end plate 6 gradually increases from the periphery to the center, the stress of each part of the middle upper end plate 6 can be adjusted by adjusting the height of each region on the middle upper end plate 6 in the up-down direction as shown in fig. 1, and the middle upper end plate 6 can be partially or completely attached to the outer upper end plate 4. Specifically, when a pressing force is applied to the outer upper end plate 4, the outer upper end plate 4 generates a pressing force on the intermediate upper end plate 6, and since the thickness of the intermediate end plate is greater than the thickness of the peripheral thick bottom of the intermediate end plate, the outer upper end plate 4 is deformed to some extent, and the contact area between the outer upper end plate 4 and the intermediate upper end plate 6 can be adjusted by changing the heights of different regions on the intermediate upper end plate 6, it can be understood that the larger the contact area between the outer upper end plate 4 and the intermediate upper end plate 6 is, the longer the service life of the outer upper end plate 4 and the intermediate upper end plate 6 is. Similarly, the larger the contact area between the outer lower end plate 5 and the intermediate lower end plate, the longer the service life of the outer lower end plate 5 and the intermediate lower end plate. Therefore, when the thickness of the middle upper end plate 6 gradually increases from the periphery to the center, and the thickness of the middle lower end plate gradually increases from the periphery to the center, the middle upper end plate 6 and the outer upper end plate 4 can be completely attached, and the middle lower end plate and the outer lower end plate 5 can be completely attached, so that the service life of the whole body is prolonged.

As shown in fig. 3 to 6, in some embodiments, the thicknesses of the intermediate upper end plate 6 and the intermediate lower end plate decrease in order from the intermediate portions toward both sides in the width direction of the cell assembly 1 (the left-right direction as viewed in fig. 1).

In some embodiments, the thickness of the intermediate upper end plate 6 increases in a step-like manner from the periphery towards the center, and the thickness of the intermediate lower end plate increases in a step-like manner from the periphery towards the center. The more the number of steps (number of steps) of the steps on the intermediate upper end plate 6, the more uniform the pressing force of the outer upper end plate 4 to the intermediate upper end plate 6, and the more the number of steps (number of steps) of the steps on the intermediate lower end plate, the more uniform the pressing force of the outer lower end plate 5 to the intermediate lower end plate. And thus the service life of the middle upper end plate 6, the middle lower end plate, the outer upper end plate 4 and the outer lower end plate 5 can be increased.

In some embodiments, the surface of the middle upper end plate 6 adjacent to the inner upper end plate 2 is a plane, the surface of the middle upper end plate 6 away from the inner upper end plate 2 is a step surface or an arc surface, the surface of the middle lower end plate adjacent to the inner lower end plate 3 is a plane, and the surface of the middle upper end plate 6 away from the inner lower end plate 3 is a step surface or an arc surface.

Specifically, when a pressure is applied to the outer upper end plate 4, the pressure on the outer upper end plate 4 is transmitted to the middle upper end plate 6, and when the inner upper end plate 2 is pressed by the middle upper end plate 6, the contact surface between the middle upper end plate 6 and the outer upper end plate 4 is an arc surface or a step surface, so that the contact area between the middle upper end plate 6 and the outer upper end plate 4 can be increased to the maximum extent. Meanwhile, the connection surface of the middle upper end plate 6 and the inner upper end plate 2 is a plane, so that the inner upper end plate 2 can be uniformly stressed, the inner upper end plate 2 can be fully contacted with the upper end of the battery assembly 1, and similarly, the middle lower end plate applies uniform pressure to the inner lower end plate 3, so that the inner lower end plate 3 is fully contacted with the upper end of the battery assembly 1, and the whole working efficiency is ensured. Can also reduce the strain of the inner upper end plate 2 and the inner lower end plate 3, and further increase the service life of the whole body.

In some embodiments, the length of the inner upper end plate 2 and the inner lower end plate 3 in the length direction of the battery assembly 1 (the front-rear direction as viewed in fig. 1) is greater than the width of the outer upper end plate 4 and the outer lower end plate 5 in the length direction of the battery assembly 1 and greater than the length of the battery assembly 1. The two ends of the inner upper end plate 2 and the two ends of the inner lower end plate 3 in the length direction of the battery pack 1 are respectively provided with a first through hole 7, the first end of a first connecting piece 10 penetrates through the first through hole 7 on the inner upper end plate 2, and the second end of the first connecting piece 10 penetrates through the first through hole 7 on the inner lower end plate 3.

As shown in fig. 1, the inner upper end plate 2 and the inner lower end plate 3 are respectively provided with a first through hole 7, the upper end of a first connecting piece 10 is matched with the first through hole 7 on the inner upper end plate 2, the lower end of the first connecting piece 10 is matched with the first through hole 7 on the inner lower end plate 3, the inner upper end plate 2 and the inner lower end plate 3 are connected through the first connecting piece 10, the battery assembly 1 can be limited in the front-rear direction, and the battery assembly 1 is prevented from sliding out from the front-rear direction.

The length of the outer upper end plate 4 and the outer lower end plate 5 in the width direction of the battery assembly 1 is larger than the width of the inner upper end plate 2 and the inner lower end plate 3 in the width direction of the battery assembly 1 and larger than the width of the battery assembly 1. Outer upper end plate 4 and outer lower end plate 5 are equipped with second through-hole 8 respectively at the ascending both ends of width direction of battery pack 1, and outer upper end plate 4 and outer lower end plate 5 pass through second connecting piece 11 and connect, and second through-hole 8 on outer upper end plate 4 is passed to the first end of second connecting piece 11, and second through-hole 8 on outer lower end plate 5 is passed to the second end of second connecting piece 11.

Be equipped with relative second through-hole 8 on outer upper end plate 4 and the outer lower end plate 5 respectively, the upper end of second connecting piece 11 cooperates with second through-hole 8 on the outer upper end plate 4, and the lower extreme of second connecting piece 11 cooperatees with second through-hole 8 on the outer lower end plate 5, links to each other outer upper end plate 4 and outer lower end plate 5 through second connecting piece 11, can restrict battery pack 1 on the left and right directions, prevents that battery pack 1 from sliding out from the left and right directions.

In some embodiments, the first through holes 7 are provided in plurality, the first through holes 7 in the inner upper end plate 2 and the first through holes 7 in the inner lower end plate 3 are arranged in one-to-one correspondence, the first connecting members 10 are provided in plurality, and the plurality of first connecting members 10 are arranged at intervals in the width direction of the battery assembly 1. The strength of the connection between the inner upper end plate 2 and the inner lower end plate 3 and the clamping force to the battery assembly 1 can be enhanced by the plurality of first connecting members 10, while the battery assembly 1 can be further prevented from slipping out in the front-rear direction.

The second through-hole 8 sets up a plurality ofly, and second through-hole 8 on the outer upper end plate 4 and the second through-hole 8 one-to-one on the outer lower end plate 5 set up, and second connecting piece 11 sets up a plurality ofly, and a plurality of second connecting pieces 11 set up along battery pack 1's length direction interval. The coupling strength between the outer upper end plate 4 and the outer lower end plate 5 and the clamping force to the inner upper end plate 2 and the inner lower end plate 3 can be enhanced by the plurality of second coupling members 11, while the battery assembly 1 can be further prevented from slipping out in the front-rear direction.

In some embodiments, the battery assembly 1 includes a plurality of battery cells 101, a first conductive plate 102, and a second conductive plate 103, the plurality of battery cells 101 are stacked in a height direction of the battery assembly 1 and clamped between the first conductive plate 102 and the second conductive plate 103, a plurality of first vent holes are respectively provided at both ends of the plurality of battery cells 101 in a length direction of the battery assembly 1, the first vent holes extend in the height direction of the battery assembly 1, the plurality of first vent holes are arranged and spaced in a width direction of the battery assembly 1, and the inner upper end plate 2 and the inner lower end plate 3 are provided with second vent holes 9 aligned with the first vent holes. Wherein, be equipped with on interior upper end plate 2 and the interior lower end plate 3 with the second venthole 9 of first venthole alignment refer to:

when the electrochemical cell 100 according to the embodiment of the present invention is assembled, the upper end of the first vent hole in the cell assembly 1 may be opposite to the second vent hole 9 in the inner upper end plate 2, and the lower end of the first vent hole in the cell assembly 1 may be opposite to the second vent hole 9 in the inner lower end plate 3. Here, because the inner upper end plate 2 and the inner lower end plate 3 can be pressed or elastically pressed by the first connecting member 10, the front end and the rear end of the inner upper end plate 2 are partially bent downward, and it should be understood that the second vent hole 9 in the bent inner upper end plate 2 is opposite to the upper end of the first vent hole of the battery assembly 1, and similarly, the second vent hole 9 in the upwardly bent inner lower end plate 3 is opposite to the lower end of the first vent hole of the battery assembly 1. Gaseous materials can enter the cell assembly 1 through the first through hole 7 and the second through hole 8 to react.

In some embodiments, the length of the middle upper end plate 6 and the middle lower end plate in the length direction of the battery assembly 1 is equal to the width of the outer upper end plate 4 and the outer lower end plate 5 in the length direction of the battery assembly 1, and the width of the middle upper end plate 6 and the middle lower end plate in the width direction of the battery assembly 1 is equal to the width of the inner upper end plate 2 and the inner lower end plate 3 in the width direction of the battery assembly 1.

As shown in fig. 1 and 2, the middle upper end plate 6 is completely located between the outer upper end plate 4 and the inner upper end plate 2, and can cover the reaction region of the battery assembly 1, so that the inner upper end plate 2 can be completely contacted with the reaction region of the battery assembly 1, and the overall reaction efficiency can be improved. The middle lower end plate is completely positioned between the outer lower end plate 5 and the inner lower end plate 3, and can cover the reaction zone of the battery assembly 1, so that the inner lower end plate 3 can be completely contacted with the reaction zone of the battery assembly 1, and the whole reaction efficiency is improved.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the present disclosure, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" and the like mean that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. An electrochemical cell, comprising:

a battery assembly;

the middle upper end plate is arranged between the inner upper end plate and the outer upper end plate, the middle lower end plate is arranged between the inner lower end plate and the outer lower end plate, the thickness of the middle upper end plate is increased from the periphery to the center, and the thickness of the middle lower end plate is increased from the periphery to the center;

the length of the inner upper end plate and the inner lower end plate in the length direction of the battery assembly is larger than the width of the outer upper end plate and the outer lower end plate in the length direction of the battery assembly and is larger than the length of the battery assembly; the length of the outer upper end plate and the outer lower end plate in the width direction of the battery pack is greater than the width of the inner upper end plate and the inner lower end plate in the width direction of the battery pack and greater than the width of the battery pack;

the two ends of the inner upper end plate and the two ends of the inner lower end plate in the length direction of the battery pack are respectively provided with a first through hole, the first end of the first connecting piece penetrates through the first through hole in the inner upper end plate, and the second end of the first connecting piece penetrates through the first through hole in the inner lower end plate; outer upper end plate with outer lower end plate is in both ends on battery pack's the width direction are equipped with the second through-hole respectively, outer upper end plate with outer lower end plate passes through the second connecting piece and connects, the first end of second connecting piece is passed second through-hole on the outer upper end plate, the second end of second connecting piece is passed second through-hole on the outer lower end plate.

2. The electrochemical cell of claim 1, wherein the intermediate upper end plate has a thickness that increases from the periphery toward the center, and the intermediate lower end plate has a thickness that increases from the periphery toward the center.

3. The electrochemical cell of claim 1, wherein the thickness of the intermediate upper end plate increases in a step-like manner from the periphery toward the center, and the thickness of the intermediate lower end plate increases in a step-like manner from the periphery toward the center.

4. The electrochemical cell of claim 3, wherein the steps are multi-step.

5. The electrochemical cell according to claim 1, wherein the surface of the middle upper end plate adjacent to the inner upper end plate is a plane, the surface of the middle upper end plate away from the inner upper end plate is a step surface or an arc surface, the surface of the middle lower end plate adjacent to the inner lower end plate is a plane, and the surface of the middle upper end plate away from the inner lower end plate is a step surface or an arc surface.

6. The electrochemical cell according to claim 1, wherein the cell assembly includes a plurality of cells, a first conductive plate, and a second conductive plate, the plurality of cells are stacked in a height direction of the cell assembly and are sandwiched between the first conductive plate and the second conductive plate, a plurality of first vent holes are respectively provided at both ends of the plurality of cells in a length direction of the cell assembly, the first vent holes extend in the height direction of the cell assembly, the plurality of first vent holes are arranged in a width direction of the cell assembly at intervals, and second vent holes aligned with the first vent holes are provided on the inner upper end plate and the inner lower end plate.

7. The electrochemical cell according to claim 1, wherein the length of the middle upper end plate and the middle lower end plate in the length direction of the cell assembly is equal to the width of the outer upper end plate and the outer lower end plate in the length direction of the cell assembly, and the width of the middle upper end plate and the middle lower end plate in the width direction of the cell assembly is equal to the width of the inner upper end plate and the inner lower end plate in the width direction of the cell assembly.

8. The electrochemical cell of claim 1, wherein the first and second connectors are a plurality of first connectors spaced apart along a width of the cell assembly, wherein the second connectors are spaced apart along a length of the cell assembly, and wherein the first and second connectors are bolts.