Single battery

Abstract

The invention provides a single battery, and relates to the technical field of secondary batteries. The single battery has a first direction and a second direction which are perpendicular to each other, and the single battery comprises a shell, a battery pole group, a flexible porous part, a busbar assembly and a cover plate assembly; a containing cavity is formed in the shell and provided with an opening in at least one end in the first direction. The multiple battery pole groups are arranged in the accommodating cavity, and tabs are arranged at the ends, facing the opening in the first direction, of the battery pole groups; the plurality of flexible porous parts are arranged in the accommodating cavity, the plurality of flexible porous parts and the plurality of battery pole groups are stacked along a second direction, and a plurality of seepage holes and / or a plurality of seepage grooves are formed in the flexible porous parts. According to the single battery, the problems of non-uniform electrolyte infiltration, inconsistent current among pole groups, increase of internal resistance of the battery, non-uniform temperature of the battery, large internal expansion stress of the battery, non-uniform stress of pole pieces and the like can be effectively solved, and the cycle life of the battery is finally prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of secondary batteries, and in particular to a single battery. Background Art

[0002] Large-capacity batteries have high volume energy density and use fewer structural parts and PACK-end components, which can significantly save system integration costs. However, existing large-capacity batteries have large pole pieces, a large number of pole pieces, and uneven electrolyte infiltration, which reduces the battery cycle life. Summary of the invention

[0003] In order to solve the problems existing in the prior art, an object of the present invention is to provide a single cell.

[0004] The present invention provides the following technical solutions:

[0005] A single cell battery has a first direction and a second direction perpendicular to each other, and the single cell battery comprises:

[0006] A housing, wherein a receiving cavity is disposed in the housing, and at least one end of the receiving cavity along the first direction has an opening;

[0007] A battery electrode group is disposed in the accommodating cavity, a plurality of the battery electrode groups are provided, and a pole ear is provided at one end of the battery electrode group along the first direction toward the opening;

[0008] A flexible porous member, disposed in the accommodating cavity, wherein a plurality of the flexible porous members are provided, wherein the plurality of the flexible porous members and the plurality of the battery electrode groups are stacked and arranged along the second direction, and wherein the flexible porous member is provided with a plurality of liquid seepage holes and / or a plurality of liquid seepage grooves;

[0009] A busbar assembly is disposed at the opening, and the busbar assembly is connected to the tab; and

[0010] A cover plate assembly is arranged to cover the opening, and the cover plate assembly is respectively connected to the housing and the bus assembly.

[0011] As a further optional solution for the single cell, the single cell further includes a fixed support plate, and the fixed support plates are arranged in pairs at two ends of the accommodating cavity along the second direction;

[0012] The flexible porous member includes a first flexible porous member and a second flexible porous member, the thickness of the first flexible porous member is less than the thickness of the second flexible porous member, the first flexible porous member is arranged between the fixed support plate and the battery pole group, and the second flexible porous member is arranged between two adjacent battery pole groups.

[0013] As a further optional solution for the single cell, the single cell further includes an insulating heat conductive member, which is disposed between the battery pole group and the flexible porous member, and has a plurality of first through holes disposed on the insulating heat conductive member, which are connected to at least part of the liquid seepage holes.

[0014] As a further optional solution for the single cell, the liquid seepage hole comprises a first liquid seepage hole and a second liquid seepage hole, the first liquid seepage hole and the second liquid seepage hole are alternately arranged along the first direction, and a cross section of the first liquid seepage hole is smaller than a cross section of the second liquid seepage hole;

[0015] The first through hole is communicated with the first liquid seepage hole;

[0016] The single battery further has a third direction, and the third direction is perpendicular to the first direction and the second direction respectively;

[0017] The seepage grooves are arranged in pairs at two sides of the first seepage hole along the third direction, and the seepage grooves are extended along the third direction.

[0018] As a further optional solution for the single cell, the busbar assembly includes a first insulating bracket and a busbar body;

[0019] One side of the first insulating support abuts against one end of the battery electrode group along the first direction toward the opening, and the other side of the first insulating support is provided with a busbar mounting groove, and the busbar mounting groove is provided with a plurality of second through holes through which the electrode tabs can pass;

[0020] The bus body is arranged in the bus mounting groove, and a plurality of third through holes are arranged on the bus body, and the third through holes are connected with the second through holes, and a pole ear connecting portion is arranged on one side of the third through holes, and the pole ear connecting portion is connected with the pole ear, and protrusions are respectively arranged at both ends of the bus body along the second direction, and the protrusions are connected with the cover plate assembly.

[0021] As a further optional solution for the single battery, a groove is provided on the pole lug connecting portion, and the groove is used to increase the resistance between the pole lug and the protrusion, so that the resistance between each pole lug and the protrusion is equal;

[0022] The single battery further has a third direction, and the third direction is perpendicular to the first direction and the second direction respectively;

[0023] The third through hole is extended along the third direction, and the groove is extended along the second direction.

[0024] As a further optional solution for the single cell, the cover plate assembly includes a cover plate body, a second insulating bracket, a pole and an adapter;

[0025] The cover body is covered on the opening, and the cover body is connected to the shell;

[0026] The second insulating bracket is arranged on a side of the cover body along the first direction toward the battery electrode group;

[0027] The pole is arranged through the cover body and the second insulating bracket;

[0028] The adapter plate is arranged on a side of the second insulating bracket along the first direction toward the battery electrode group, and the adapter plate is respectively connected to the pole and the busbar assembly.

[0029] As a further optional solution for the single battery, the second insulating bracket has a first surface perpendicular to the first direction and a second surface parallel to the first direction, an explosion-proof valve avoidance hole is provided at an edge of the first surface close to the second surface, and a liquid injection avoidance hole is provided on the second surface;

[0030] The cover plate body is provided with an explosion-proof valve aligned with the explosion-proof valve avoidance hole, and the shell is provided with a liquid injection hole aligned with the liquid injection avoidance hole;

[0031] The hole wall of the injection hole is provided with an internal thread portion, and a sealing rubber plug is provided in the injection hole, and the sealing rubber plug is threadably matched with the internal thread portion.

[0032] As a further optional solution for the single cell, a fire extinguishing agent storage compartment is provided on the second insulating bracket, and the fire extinguishing agent storage compartment is used to store capsule fire extinguishing agent.

[0033] As a further optional solution for the single battery, the housing includes a first shell and a second shell connected to each other, the first shell and the second shell are both extended along the first direction, and the first shell and the second shell together form the accommodating cavity;

[0034] A reinforcing rib is provided on a surface of the first shell and / or the second shell that is perpendicular to the second direction, and the reinforcing rib extends perpendicular to the first direction.

[0035] The embodiments of the present invention have the following beneficial effects:

[0036] In the above-mentioned single cell, the battery pole group and the flexible porous member are stacked along the second direction in the receiving cavity of the shell, and part of the electrolyte injected into the receiving cavity can be stored in the pores of the flexible porous member. During charging, the battery pole group expands and squeezes the flexible porous member, causing the flexible porous member to compress. The electrolyte stored in the flexible porous member overflows from the seepage holes and / or the seepage grooves and enters the battery pole group, which can fully infiltrate the electrode material of the battery pole group, prevent the electrolyte from decomposing and drying up during the use of the single cell, improve the battery capacity attenuation, and thus increase the battery cycle life.

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 A schematic diagram of the internal structure of a single cell provided by an embodiment of the present invention is shown;

[0040] Figure 2 A schematic diagram showing the matching relationship between a battery electrode group and a flexible porous member in a single battery provided by an embodiment of the present invention is shown;

[0041] Figure 3 A schematic diagram of the structure of a flexible porous member in a single cell provided by an embodiment of the present invention is shown;

[0042] Figure 4 A partial structural schematic diagram of a single cell provided by an embodiment of the present invention is shown;

[0043] Figure 5 A schematic structural diagram of a busbar assembly in a single cell provided by an embodiment of the present invention is shown;

[0044] Figure 6 A schematic structural diagram of a cover plate assembly in a single cell provided by an embodiment of the present invention is shown;

[0045] Figure 7 A schematic diagram of an explosion of a single cell provided by an embodiment of the present invention is shown;

[0046] Figure 8 A schematic diagram of the structure of a shell in a single cell provided by an embodiment of the present invention is shown;

[0047] Fig. 9 A schematic structural diagram of a housing of a single cell provided by an embodiment of the present invention is shown in another viewing angle;

[0048] Fig.10 A partial structural schematic diagram of a first shell in a single cell provided by an embodiment of the present invention is shown.

[0049] Description of main component symbols:

[0050] 100-housing; 101-accommodating cavity; 110-first housing; 111-first positioning groove; 112-liquid injection hole; 112a-internal thread portion; 112b-sealing groove; 113-sealing rubber plug; 114-sealing nail; 120-second housing; 121-second positioning groove; 130-reinforcement rib; 200-battery pole group; 210-ear; 300-flexible porous member; 301-first flexible porous member; 302-second flexible porous member; 310-liquid seepage hole; 311-first liquid seepage hole; 312-second liquid seepage hole; 320-liquid seepage groove; 400-bus assembly; 410-first insulating bracket; 411-bus mounting groove; 412-second through hole; 42 0-busbar body; 421-third through hole; 422-ear connection part; 423-protrusion; 424-groove; 500-cover assembly; 510-cover body; 511-pole lead hole; 512-explosion-proof valve; 520-second insulating bracket; 521-fourth through hole; 522-first surface; 523-second surface; 524-explosion-proof valve avoidance hole; 525-liquid injection avoidance hole; 526-fire extinguishing agent storage compartment; 530-pole; 540-adapter; 541-pole welding hole; 550-welding ring; 560-upper insulating member; 570-sealing ring; 600-fixed support plate; 700-insulating heat conductive member; 710-first through hole; 800-Mylar film;

[0051] X-first direction; Y-second direction; Z-third direction. DETAILED DESCRIPTION

[0052] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0053] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. In contrast, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0054] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of the template are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0057] The inventors of the present disclosure have found that the existing large-capacity battery has large pole pieces and a large number of pole pieces, which makes lamination difficult, places high demands on equipment, increases the defect rate, and makes it difficult to electrically connect the pole group and the pole column. In addition, large-capacity batteries also have problems such as uneven electrolyte infiltration, inconsistent current between pole groups, increased battery internal resistance, uneven battery temperature, large internal expansion stress of the battery, and uneven force on the pole pieces, which reduces the battery cycle life.

[0058] Example

[0059] Please also read Figure 1 , Figure 2 and Figure 3This embodiment provides a single cell, specifically a super-large capacity battery. The single cell has a first direction X and a second direction Y that are perpendicular to each other, and the single cell includes a housing 100, a battery electrode group 200, a flexible porous member 300, a busbar assembly 400, and a cover assembly 500.

[0060] The housing 100 is provided with a receiving cavity 101 , and at least one end of the receiving cavity 101 along the first direction X has an opening.

[0061] The battery electrode group 200 is disposed in the accommodating cavity 101 . A plurality of battery electrode groups 200 are provided. A pole ear 210 is provided at one end of the battery electrode group 200 along the first direction X toward the opening.

[0062] The flexible porous member 300 is disposed in the accommodating cavity 101 . A plurality of flexible porous members 300 are provided. The plurality of flexible porous members 300 and the plurality of battery electrode groups 200 are stacked and arranged along the second direction Y. In addition, the flexible porous member 300 is provided with a plurality of liquid seepage holes 310 and / or a plurality of liquid seepage grooves 320 .

[0063] The busbar assembly 400 is disposed at the opening, and the busbar assembly 400 is connected to the tab 210. Meanwhile, the cover plate assembly 500 is disposed on the opening, and the cover plate assembly 500 is connected to the housing 100 and the busbar assembly 400 respectively.

[0064] In the above-mentioned single cell, the battery pole group 200 and the flexible porous member 300 are stacked in the accommodating cavity 101 of the housing 100 along the second direction Y, and part of the electrolyte injected into the accommodating cavity 101 can be stored in the pores of the flexible porous member 300. During charging, the battery pole group 200 expands and squeezes the flexible porous member 300, causing the flexible porous member 300 to compress. The electrolyte stored in the flexible porous member 300 overflows from the seepage holes 310 and / or the seepage grooves 320 and enters the battery pole group 200, which can fully infiltrate the electrode material of the battery pole group 200, prevent the electrolyte from decomposing and drying up during the use of the single cell, improve the battery capacity attenuation, and thus increase the battery cycle life.

[0065] In addition, due to the compressibility of the flexible porous member 300, an initial pre-tightening force can be applied to the battery electrode group 200 and the flexible porous member 300 when assembling a single battery, so that the pressure of the single battery is constant during use, which can also improve the battery cycle life.

[0066] In some embodiments, the battery electrode group 200 is composed of a positive electrode sheet, a negative electrode sheet, a separator, a positive electrode tab and a negative electrode tab. The positive electrode sheet and the negative electrode sheet are separated by a separator, and the positive electrode sheet, the separator and the negative electrode sheet can form the battery electrode group 200 by lamination or winding. The positive electrode tab and the negative electrode tab are located at the end of the battery electrode group 200 along the first direction X.

[0067] It can be understood that the positive electrode tab and the negative electrode tab can be arranged at the same end of the battery electrode group 200 along the first direction X. Alternatively, the positive electrode tab can be arranged at one end of the battery electrode group 200 along the first direction X, and the negative electrode tab can be arranged at the other end of the battery electrode group 200 along the first direction X.

[0068] In this embodiment, the battery electrode group 200 is provided with tabs 210 at both ends along the first direction X. One end is a positive electrode tab, and the other end is a negative electrode tab.

[0069] Accordingly, both ends of the accommodating chamber 101 along the first direction X have openings. At the same time, two busbar assemblies 400 are provided, namely, a positive busbar assembly and a negative busbar assembly. Two cover plate assemblies 500 are also provided, namely, a positive cover plate assembly and a negative cover plate assembly.

[0070] Among them, the positive electrode tab is connected to the positive electrode cover plate assembly through the positive electrode bus assembly, and the negative electrode tab is connected to the negative electrode cover plate assembly through the negative electrode bus assembly.

[0071] Since the structure of the positive electrode lug is consistent with that of the negative electrode lug, the structure of the positive electrode bus bar assembly is consistent with that of the negative electrode bus bar assembly, the structure of the positive electrode cover plate assembly is consistent with that of the negative electrode cover plate assembly, and the connection method between the positive electrode lug, the positive electrode bus bar assembly and the positive electrode cover plate assembly is also the same as the connection method between the negative electrode lug, the negative electrode bus bar assembly and the negative electrode cover plate assembly, no distinction will be made below, and only one group of the electrode lug 210, the bus bar assembly 400 and the cover plate assembly 500 will be used as an example for explanation.

[0072] In some embodiments, the flexible porous member 300 is made of foam, which has good elasticity and resistance to electrolyte corrosion.

[0073] The flexible porous member 300 disposed between the battery pole groups 200 can form a SEI film (Solid Electrolyte Interface membrane) during the formation process. During charging, the pole pieces expand, squeezing the gas generated by the side reactions between the pole pieces out of the battery pole group 200, which can improve the battery interface quality, provide a constant pressure during the charge and discharge cycle, and increase the battery cycle life.

[0074] In some embodiments, the above-mentioned single battery further includes a fixed support plate 600 , and the fixed support plates 600 are arranged in pairs at two ends of the accommodating cavity 101 along the second direction Y.

[0075] Accordingly, the flexible porous member 300 includes a first flexible porous member 301 and a second flexible porous member 302. The thickness of the first flexible porous member 301 is less than that of the second flexible porous member 302, and the first flexible porous member 301 is disposed between the fixed support plate 600 and the battery pole group 200, and the second flexible porous member 302 is disposed between two adjacent battery pole groups 200.

[0076] It can be understood that the size of the cross section of the fixed support plate 600 along the second direction Y is equal to the size of the battery electrode group 200, and the fixed support plate 600 can be made of PP material resistant to electrolyte. In addition, the size of the cross section of the flexible porous member 300 along the second direction Y is also similar to the size of the battery electrode group 200.

[0077] In this embodiment, the battery pole groups 200 are arranged in pairs, and the two battery pole groups 200 of the same pair are stacked together, and the second flexible porous member 302 is arranged between each pair of battery pole groups 200. At this time, each battery pole group 200 is provided with a flexible porous member 300 adjacent to it and provides the electrolyte required for infiltration. Since the first flexible porous member 301 is only provided with a battery pole group 200 on one side, and the battery pole groups 200 are provided on both sides of the second flexible porous member 302, the thickness of the second flexible porous member 302 is greater than that of the first flexible porous member 301, so as to store more electrolyte, so that the electrolyte can be provided to each battery pole group 200 more evenly, and each battery pole group 200 can be infiltrated.

[0078] Optionally, the thickness of the first flexible porous member 301 is half the thickness of the second flexible porous member 302. The thickness of the first flexible porous member 301 refers to the dimension of the first flexible porous member 301 along the second direction Y, and the thickness of the second flexible porous member 302 refers to the dimension of the second flexible porous member 302 along the second direction Y.

[0079] In some embodiments, the above-mentioned single battery further includes an insulating heat conductive member 700 . The insulating heat conductive member 700 is disposed between the battery electrode group 200 and the flexible porous member 300 , and is provided with a plurality of first through holes 710 , which are connected to at least part of the liquid seepage holes 310 .

[0080] Since each battery pole group 200 is provided with and only one flexible porous member 300 adjacent thereto, the number of insulating heat-conducting members 700 is equal to the number of battery pole groups 200. The reasonably arranged insulating heat-conducting components not only ensure the insulation between each battery pole group 200, but also have high heat conduction efficiency, thereby ensuring that each battery pole group 200 is in the optimal uniform operating temperature range, improving the consistency of the performance of the battery pole group 200, extending the battery life, and increasing the overall strength of the above-mentioned single battery.

[0081] In addition, the first through hole 710 on the insulating thermal conductive member 700 is connected to at least part of the liquid seepage holes 310, so that the electrolyte stored in the flexible porous member 300 can overflow through the liquid seepage holes 310 and the first through hole 710 when the flexible porous member 300 is compressed and enter the battery electrode group 200.

[0082] It can be understood that the size of the cross section of the insulating heat conductive member 700 along the second direction perpendicular to the second direction Y is similar to the size of the battery electrode group 200. The insulating heat conductive member 700 can be any insulating material, preferably an insulating material with high thermal conductivity or a heat conductive metal member after insulation treatment, so as to effectively and quickly conduct the heat inside the battery electrode group 200 to the housing 100, and then transfer it to the external cooling structure such as the cold plate through the housing 100.

[0083] Optionally, the flexible porous member 300 is coated with glue on both sides. One side of the first flexible porous member 301 is bonded to the insulating heat conductive member 700, and the other side is bonded to the fixed support plate 600. Both sides of the second flexible porous member 302 are bonded to the insulating heat conductive member 700 respectively.

[0084] Furthermore, the liquid seepage hole 310 includes a first liquid seepage hole 311 and a second liquid seepage hole 312 , and the first liquid seepage hole 311 and the second liquid seepage hole 312 are alternately arranged along the first direction X.

[0085] The cross section of the first liquid seepage hole 311 is smaller than the cross section of the second liquid seepage hole 312. Meanwhile, the first through hole 710 is connected to the first liquid seepage hole 311.

[0086] Optionally, the first seepage hole 311 , the second seepage hole 312 and the first through hole 710 are all circular holes. The diameter of the second seepage hole 312 is twice the diameter of the first seepage hole 311 , and the diameter of the first seepage hole 311 is slightly larger than or equal to the diameter of the first through hole 710 .

[0087] Furthermore, the above-mentioned single battery also has a third direction Z, and the third direction Z is perpendicular to the first direction X and the second direction Y respectively.

[0088] The seepage grooves 320 are disposed in pairs at two sides of the first seepage hole 311 along the third direction Z, and the seepage grooves 320 are extended along the third direction Z.

[0089] It can be understood that the first seepage holes 311 , the second seepage holes 312 and the seepage grooves 320 provided on the flexible porous member 300 are conducive to the extrusion of the electrolyte stored in the flexible porous member 300 , and can also increase the compressibility of the flexible porous member 300 .

[0090] Please also read Figure 4 and Figure 5In some embodiments, the busbar assembly 400 is composed of a first insulating bracket 410 and a busbar body 420 .

[0091] One side of the first insulating bracket 410 abuts against one end of the battery electrode group 200 toward the opening along the first direction X, and the other side of the first insulating bracket 410 is provided with a busbar mounting groove 411, and the busbar mounting groove 411 is provided with a plurality of second through holes 412 for accommodating the pole ears 210 to pass through.

[0092] Correspondingly, the busbar body 420 is disposed in the busbar mounting groove 411. A plurality of third through holes 421 are disposed on the busbar body 420, and the third through holes 421 are connected to the second through holes 412. A tab connection portion 422 is disposed on one side of the third through hole 421, and the tab connection portion 422 is connected to the tab 210. Both ends of the busbar body 420 along the second direction Y are respectively provided with protrusions 423, and the protrusions 423 are connected to the cover plate assembly 500.

[0093] When in use, the tab 210 passes through the second through hole 412 and the third through hole 421 in sequence, and then is bent and welded to the tab connection portion 422, and is electrically connected to the tab connection portion 422. At the same time, the protrusion 423 is electrically connected to the cap assembly 500, so that the tab 210 is electrically connected to the cap assembly 500 through the busbar body 420.

[0094] Optionally, the busbar body 420 in the positive busbar assembly is made of aluminum alloy, and the busbar body 420 in the negative busbar assembly is made of copper.

[0095] As mentioned above, the battery pole groups 200 are arranged in pairs, and the two battery pole groups 200 of the same pair are stacked together. After the pole tabs 210 of the two battery pole groups 200 are combined, they pass through the same second through hole 412 and the same third through hole 421 in turn, and are welded together to the pole tab connection portion 422 on one side of the third through hole 421. In addition, the pole tabs 210 of the two adjacent pairs of battery pole groups 200 are bent toward each other.

[0096] It can be understood that the plurality of second through holes 412 are uniformly distributed on the first insulating support 410 along the second direction Y. The second through hole 412 is a rectangular hole, and the length of the second through hole 412 is greater than the width of the tab 210, and the width of the second through hole 412 is greater than the sum of the thicknesses of the two tabs 210. The plurality of third through holes 421 are uniformly distributed on the busbar body 420 along the second direction Y, and the size of the third through holes 421 is the same as that of the second through holes 412.

[0097] In addition, a chamfer is provided on a side of the second through hole 412 facing away from the busbar body 420 , so that the tab 210 can pass through the second through hole 412 .

[0098] Furthermore, a groove 424 is provided on the tab connection portion 422. The groove 424 is used to increase the resistance between the tab 210 and the protrusion 423, so that the resistance between each tab 210 and the protrusion 423 is equal.

[0099] It can be understood that after the groove 424 is provided on the pole tab connection portion 422 , the current derived from the pole tab 210 forms a serpentine path, and the cross-sectional area of ​​the current path is reduced, thereby increasing the resistance between the pole tab 210 and the protrusion 423 .

[0100] On this basis, along the second direction Y, the more and longer the grooves 424 on the pole ear connecting portion 422 are closer to the protruding portion 423, so that the current path is longer and the cross-sectional area is smaller, which can ensure that the resistance from each pole ear 210 to the protruding portion 423 is equal, thereby evenly distributing the current entering or outputting each battery pole group 200, which is beneficial to the uniform current distribution of each battery pole group 200 in the single cell charging and discharging process, improving the consistency of each battery pole group 200, and thus the battery cycle life.

[0101] In this embodiment, the third through hole 421 is extended along the third direction Z, and the groove 424 is extended along the second direction Y.

[0102] At this time, by adjusting the number and length of the grooves 424 on the pole ear connecting portion 422, the resistance between the pole ear 210 welded at the pole ear connecting portion 422 and the protrusion 423 can be adjusted, so that the resistance between the pole ear 210 closer to the protrusion 423 and the protrusion 423 increases more until the resistance from each pole ear 210 to the protrusion 423 is equal.

[0103] Please also read Figure 4 and Figure 6 In some embodiments, the cover assembly 500 includes a cover body 510 , a second insulating bracket 520 , a pole 530 and an adapter 540 .

[0104] The cover body 510 is disposed on the opening, and the cover body 510 is connected to the housing 100. The second insulating bracket 520 is disposed on one side of the cover body 510 along the first direction X toward the battery electrode group 200.

[0105] The pole 530 is passed through the cover body 510 and the second insulating bracket 520. The adapter 540 is arranged on one side of the second insulating bracket 520 along the first direction X toward the battery pole group 200, and the adapter 540 is respectively connected to the pole 530 and the busbar assembly 400, specifically connected to the protrusion 423 in the busbar assembly 400, thereby realizing the electrical connection between the pole 530 and the pole ear 210.

[0106] Specifically, the center positions of the two ends of the cover body 510 along the second direction Y are respectively provided with pole lead-out holes 511, and the second insulating bracket 520 is provided with fourth through holes 521 corresponding to the pole lead-out holes 511. In addition, the cover assembly 500 further includes a welding ring 550, an upper insulating member 560 and a sealing ring 570.

[0107] The pole 530 penetrates the cover body 510 and the second insulating bracket 520 along the first direction X. The upper insulating member 560 and the sealing ring 570 are both disposed around the pole 530 to separate the pole 530 from the hole wall of the pole lead-out hole 511 .

[0108] In addition, the welding ring 550 is welded and fixed to the pole 530, and abuts against the side of the upper insulating member 560 away from the cover body 510 along the first direction X. Thus, the welding ring 550, the pole 530 and the adapter 540 cooperate to clamp the upper insulating member 560, the cover body 510, the second insulating bracket 520 and the sealing ring 570 therein, so that the entire cover assembly 500 is connected as a whole.

[0109] Optionally, the adapter plate 540 in the positive electrode cover plate assembly is formed by welding and pressing of multiple layers of aluminum foil, and the adapter plate 540 in the negative electrode cover plate assembly is formed by welding and pressing of multiple layers of copper foil. A pole welding hole 541 is provided at one end of the adapter plate 540, and the pole 530 penetrates the pole welding hole 541 and is welded to the pole welding hole 541. The other end of the adapter plate 540 is bent 90° and connected to the protrusion 423.

[0110] Optionally, the interior of the pole 530 is provided with an internal thread so as to be electrically connected to an external structure.

[0111] Furthermore, the second insulating bracket 520 has a first surface 522 perpendicular to the first direction X and a second surface 523 parallel to the first direction X. An explosion-proof valve avoidance hole 524 is provided at the edge of the first surface 522 close to the second surface 523 , and an injection avoidance hole 525 is provided on the second surface 523 .

[0112] Correspondingly, the cover body 510 is provided with an explosion-proof valve 512 aligned with the explosion-proof valve avoidance hole 524 , and the housing 100 is provided with a liquid injection hole 112 aligned with the liquid injection avoidance hole 525 .

[0113] It can be understood that the electrolyte is injected into the accommodating cavity 101 through the injection hole 112 on the shell 100. During the use of the single battery, the side of the shell 100 on which the injection hole 112 is provided is usually placed upward, and the second surface 523 of the second insulating bracket 520 is also arranged upward. At this time, the explosion-proof valve avoidance hole 524 provided on the edge of the first surface 522 close to the second surface 523 is located at the top of the second insulating bracket 520, and the explosion-proof valve 512 aligned with the explosion-proof valve avoidance hole 524 is correspondingly located on the upper side of the cover body 510, so as to be away from the electrolyte liquid surface in the accommodating cavity 101. When thermal runaway occurs, the explosion-proof valve 512 ruptures. Since the explosion-proof valve 512 is away from the electrolyte liquid surface, the electrolyte spraying can be alleviated and the safety risk of thermal runaway can be reduced.

[0114] In this embodiment, the second surface 523 is also parallel to the second direction Y. At this time, two ends of the second insulating bracket 520 along the second direction Y form avoidance grooves to facilitate welding of the adapter plate 540 and the protrusion 423 .

[0115] Furthermore, a fire extinguishing agent storage compartment 526 is provided on the second insulating bracket 520, and the fire extinguishing agent storage compartment 526 is used to store capsule fire extinguishing agent.

[0116] Before assembling the cover assembly 500, the fire extinguishing agent capsule is loaded into the fire extinguishing agent storage compartment 526, so that the fire extinguishing agent capsule is encapsulated between the second insulating bracket 520 and the cover body 510. When the single cell thermal runaway occurs, the internal temperature rises to the point where the second insulating bracket 520 melts, and the shell 100 of the fire extinguishing agent capsule ruptures at a certain temperature response, releasing the internal fire extinguishing agent to quickly absorb heat, inhibiting the exothermic reaction of the single cell, and suppressing the thermal runaway of the single cell at the primary stage, thereby preventing the combustion and explosion of the single cell.

[0117] See also Figure 7 In some embodiments, the housing 100 includes a first shell 110 and a second shell 120 connected to each other. The first shell 110 and the second shell 120 are both extended along the first direction X, and the first shell 110 and the second shell 120 together form a receiving cavity 101.

[0118] Splitting the outer shell 100 into a first shell 110 and a second shell 120 is not only conducive to the stacking of the battery pole group 200, the flexible porous member 300, the fixed support plate 600 and the insulating heat conductive member 700 into the shell, but also can apply a pre-tightening force to the battery pole group 200 by extrusion before welding the busbar assembly 400 and the cover plate assembly 500, thereby helping to improve battery performance.

[0119] It can be understood that when the preload force is applied to the battery electrode group 200, the stacked battery electrode group 200, the flexible porous member 300, the fixed support plate 600 and the insulating heat conductive member 700 are squeezed along the second direction Y, so that the flexible porous member 300 is compressed and deformed along the second direction Y. During the charging process, the battery electrode group 200 also expands along the second direction Y.

[0120] Furthermore, a reinforcing rib 130 is provided on a surface of the first shell 110 and / or the second shell 120 that is perpendicular to the second direction Y, and the reinforcing rib 130 extends perpendicular to the first direction X.

[0121] The surface of the first shell 110 and / or the second shell 120 perpendicular to the second direction Y is a pressure surface. A plurality of reinforcing ribs 130 are arranged on the pressure surface, which can improve the rigidity of the battery shell. There is no need to apply pre-tightening force during the grouping process. The batteries can be used independently, reducing the difficulty and cost of battery grouping.

[0122] Please combine Figure 8 and Fig. 9 In this embodiment, the first shell 110 and the second shell 120 are both L-shaped and have a large surface perpendicular to the third direction Z and a small surface perpendicular to the second direction Y. The reinforcing ribs 130 are respectively arranged on the small surfaces of the first shell 110 and the second shell 120 and are perpendicular to the corresponding large surfaces.

[0123] A first positioning groove 111 is processed on the side of the small face of the first shell 110 away from the large face, and a side of the large face of the second shell 120 away from the small face engages with the first positioning groove 111 on the first shell 110. Similarly, a second positioning groove 121 is processed on the side of the small face of the second shell 120 away from the large face, and a side of the large face of the first shell 110 away from the small face engages with the second positioning groove 121 on the second shell 120. During assembly, the first shell 110 and the second shell 120 are first positioned by the first positioning groove 111 and the second positioning groove 121, and then fixed by welding.

[0124] See also Fig.10 In addition, during use, the first shell 110 is placed with its large surface facing upward, and the injection hole 112 is arranged on the large surface of the first shell 110 .

[0125] Furthermore, an internal thread portion 112 a is provided on the hole wall of the liquid injection hole 112 , and a sealing rubber plug 113 is provided in the liquid injection hole 112 , and the sealing rubber plug 113 is threadably matched with the internal thread portion 112 a .

[0126] By flanging and tapping the injection hole 112 to form an internal thread portion 112a, and making a matching external thread on the sealing plug 113, the sealing plug 113 can be installed reliably, the chemical sealing performance is improved, it can be operated in a normal indoor environment, and the control cost caused by moderate control can be reduced.

[0127] In addition, a sealing groove 112 b is provided at one end of the injection hole 112 exposed on the large surface of the first shell 110 , and a sealing pin 114 is embedded in the sealing groove 112 b . The sealing pin 114 is welded and fixed to the first shell 110 , further enhancing the sealing of the injection hole 112 .

[0128] Please refer again Figure 7 In some embodiments, the single cell further comprises a Mylar film 800. The Mylar film 800 is extended along the first direction X, has a main body perpendicular to the third direction Z and a flange perpendicular to the second direction Y, and two Mylar films 800 are provided.

[0129] During assembly, the end of the main part of the Mylar film 800 along the first direction X is connected to the first insulating bracket 410 by heat melting, and the flange of the Mylar film 800 is connected to the fixed support plate 600 and the first insulating bracket 410 by heat melting.

[0130] On the one hand, the above-mentioned single cell can store electrolyte by arranging a compressible flexible porous member 300 between the battery pole groups 200, so that the electrolyte overflows and infiltrates the electrode material of the battery pole group 200 when the battery pole group 200 expands, thereby preventing the electrolyte from decomposing and drying up during use, improving the battery capacity attenuation, and allowing the initial pre-tightening force to be applied to the battery pole group 200 and the flexible porous member 300 during assembly, so that the pressure of the single cell is constant during use. On the other hand, the above-mentioned single cell also arranges an insulating heat-conducting member 700 between the battery pole group 200 and the flexible porous member 300, so that the insulation between each battery pole group 200 is ensured while having high thermal conductivity, thereby ensuring that each battery pole group 200 is in the best uniform operating temperature range, and improving the consistency of the performance of the battery pole group 200. On the other hand, the above-mentioned single cell optimizes the structure of the busbar body 420 to make the resistance between each pole ear 210 and the protrusion 423 equal, and then make the resistance from each battery pole group 200 to the pole 530 equal, so as to evenly distribute the current entering or outputting each battery pole group 200, which is conducive to the uniform current distribution of each battery pole group 200 in the charging and discharging process of the single cell, and improves the consistency of each battery pole group 200. Therefore, the above-mentioned single cell can effectively improve the problems of uneven electrolyte infiltration, inconsistent current between pole groups, increased battery internal resistance, uneven battery temperature, large internal expansion stress of the battery, uneven force on the pole piece, etc., and finally improve the battery cycle life.

[0131] In addition, the above-mentioned single battery, by splitting the outer shell 100 into a first shell 110 and a second shell 120, is not only conducive to the stacked battery pole group 200, the flexible porous member 300, the fixed support plate 600 and the insulating heat conductive member 700 entering the shell, but can also apply a pre-tightening force to the battery pole group 200 by extrusion before welding the busbar assembly 400 and the cover plate assembly 500, thereby helping to improve battery performance and reduce the difficulty and cost of battery grouping.

[0132] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limiting, and thus other examples of the exemplary embodiments may have different values.

[0133] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0134] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A single cell battery, characterized in that: Having a first direction and a second direction perpendicular to each other, the single battery comprises: A housing, wherein a receiving cavity is disposed in the housing, and at least one end of the receiving cavity along the first direction has an opening; A battery electrode group is disposed in the accommodating cavity, a plurality of the battery electrode groups are provided, and a pole ear is provided at one end of the battery electrode group along the first direction toward the opening; A flexible porous member, disposed in the accommodating cavity, wherein a plurality of the flexible porous members are provided, wherein the plurality of the flexible porous members and the plurality of the battery electrode groups are stacked and arranged along the second direction, and wherein the flexible porous member is provided with a plurality of liquid seepage holes and / or a plurality of liquid seepage grooves; A busbar assembly is disposed at the opening, and the busbar assembly is connected to the tab; and A cover plate assembly is arranged to cover the opening, and the cover plate assembly is respectively connected to the housing and the bus assembly.

2. The single cell according to claim 1, characterized in that: The single battery further includes a fixed support plate, and the fixed support plates are arranged in pairs at two ends of the accommodating cavity along the second direction; The flexible porous member includes a first flexible porous member and a second flexible porous member, the thickness of the first flexible porous member is less than the thickness of the second flexible porous member, the first flexible porous member is arranged between the fixed support plate and the battery pole group, and the second flexible porous member is arranged between two adjacent battery pole groups.

3. The single cell according to claim 1, characterized in that: The single battery further comprises an insulating heat-conducting member, which is arranged between the battery pole group and the flexible porous member. The insulating heat-conducting member is provided with a plurality of first through holes, which are connected to at least part of the liquid seepage holes.

4. The single cell according to claim 3, characterized in that: The liquid seepage hole comprises a first liquid seepage hole and a second liquid seepage hole, the first liquid seepage hole and the second liquid seepage hole are alternately arranged along the first direction, and the cross section of the first liquid seepage hole is smaller than the cross section of the second liquid seepage hole; The first through hole is communicated with the first liquid seepage hole; The single battery further has a third direction, and the third direction is perpendicular to the first direction and the second direction respectively; The seepage grooves are arranged in pairs at two sides of the first seepage hole along the third direction, and the seepage grooves are extended along the third direction.

5. The single cell according to any one of claims 1 to 4, characterized in that: The busbar assembly comprises a first insulating bracket and a busbar body; One side of the first insulating support abuts against one end of the battery electrode group along the first direction toward the opening, and the other side of the first insulating support is provided with a busbar mounting groove, and the busbar mounting groove is provided with a plurality of second through holes through which the electrode tabs can pass; The bus body is arranged in the bus mounting groove, and a plurality of third through holes are arranged on the bus body, and the third through holes are connected with the second through holes, and a pole ear connecting portion is arranged on one side of the third through holes, and the pole ear connecting portion is connected with the pole ear, and protrusions are respectively arranged at both ends of the bus body along the second direction, and the protrusions are connected with the cover plate assembly.

6. The single cell according to claim 5, characterized in that: The pole lug connecting portion is provided with a groove, and the groove is used to increase the resistance between the pole lug and the protrusion, so that the resistance between each pole lug and the protrusion is equal; The single battery further has a third direction, and the third direction is perpendicular to the first direction and the second direction respectively; The third through hole is extended along the third direction, and the groove is extended along the second direction.

7. The single cell according to any one of claims 1 to 4, characterized in that: The cover plate assembly comprises a cover plate body, a second insulating bracket, a pole and an adapter plate; The cover body is covered on the opening, and the cover body is connected to the shell; The second insulating bracket is arranged on a side of the cover body along the first direction toward the battery electrode group; The pole is arranged through the cover body and the second insulating bracket; The adapter plate is arranged on a side of the second insulating bracket along the first direction toward the battery electrode group, and the adapter plate is respectively connected to the pole and the busbar assembly.

8. The single cell according to claim 7, characterized in that: The second insulating bracket has a first surface perpendicular to the first direction and a second surface parallel to the first direction, an explosion-proof valve avoidance hole is provided at an edge of the first surface close to the second surface, and a liquid injection avoidance hole is provided on the second surface; The cover plate body is provided with an explosion-proof valve aligned with the explosion-proof valve avoidance hole, and the shell is provided with a liquid injection hole aligned with the liquid injection avoidance hole; The hole wall of the injection hole is provided with an internal thread portion, and a sealing rubber plug is provided in the injection hole, and the sealing rubber plug is threadably matched with the internal thread portion.

9. The single cell according to claim 7, characterized in that: The second insulating bracket is provided with a fire extinguishing agent storage compartment, and the fire extinguishing agent storage compartment is used to store capsule fire extinguishing agent.

10. The single cell according to any one of claims 1 to 4, characterized in that: The housing comprises a first shell and a second shell connected to each other, the first shell and the second shell are both extended along the first direction, and the first shell and the second shell together form the accommodating cavity; A reinforcing rib is provided on a surface of the first shell and / or the second shell that is perpendicular to the second direction, and the reinforcing rib extends perpendicular to the first direction.

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