CN219759901U - Battery cell - Google Patents

Abstract

The utility model relates to the technical field of batteries, and provides a battery, which comprises: the battery cell comprises a battery cell main body and a tab led out from the end part of the battery cell main body; the pole assembly is provided with a connecting surface facing the pole lug, a plurality of protrusions facing the pole lug are formed on the connecting surface, and the protrusions are welded with the pole lug in a resistance welding way; the total area of orthographic projection of the plurality of protrusions on the connecting surface is x, the lug comprises a plurality of single-sheet lugs which are stacked in the thickness direction, and the thickness of the single-sheet lugs is a, and a/x is more than or equal to 0.06 and less than or equal to 0.5. The battery provided by the utility model improves the reliability of the battery.

Description

Battery cell

Technical Field

The utility model relates to the technical field of batteries, in particular to a battery.

Background

In the related art, the tab and the pole in the battery can be welded by resistance welding, but when resistance welding is adopted, the heat productivity is high due to the fact that the pole overcurrent area is small, and other components of the battery around the pole component can be affected by high temperature caused by the heat productivity.

Disclosure of Invention

The utility model provides a battery, which improves the reliability of the battery.

The present utility model provides a battery comprising:

the battery cell comprises a battery cell main body and a tab led out from the end part of the battery cell main body;

the pole assembly is provided with a connecting surface facing the pole lug, a plurality of protrusions facing the pole lug are formed on the connecting surface, and the protrusions are welded with the pole lug in a resistance welding mode;

the total area of orthographic projection of the protrusions on the connecting surface is x, the lug comprises a plurality of single-piece lugs which are stacked in the thickness direction, and the thickness of each single-piece lug is a, and a/x is more than or equal to 0.06 and less than or equal to 0.5.

The battery provided by the utility model has the advantages that the connection surface of the pole post component and the pole lug which are welded by resistance welding is provided with a plurality of bulges, and the bulges and the pole lug are welded by resistance welding; when the thickness of the single-layer pole piece is too large and the total area of orthographic projection of the plurality of bulges on the connecting surface is too small, if high current is selected for resistance welding, the heat productivity of the plurality of bulges is large, and the high temperature caused by the large heat productivity can influence the tightness of sealing pieces around the pole assembly and the reliability of other assemblies; if the resistance welding is performed with small current, a preset welding effect is not easy to reach between the tab and the plurality of protrusions; according to the utility model, the ratio of the thickness a of the single lug to the total area x of orthographic projections of the plurality of projections on the connecting surface is 0.06-0.5, so that the problem of large heating value caused by large current selection in resistance welding is avoided, high temperature caused by large heating value is avoided, and the sealing performance of sealing elements around the pole assembly and the reliability of other assemblies are ensured; meanwhile, the fact that small current is selected for resistance welding is avoided, the preset welding effect cannot be achieved between the lug and the protrusions, and the welding effect of the lug and the pole assembly is guaranteed.

Drawings

For a better understanding of the present disclosure, reference may be made to the embodiments illustrated in the following drawings. The components in the drawings are not necessarily to scale and related elements may be omitted in order to emphasize and clearly illustrate the technical features of the present disclosure. In addition, the relevant elements or components may have different arrangements as known in the art. Furthermore, in the drawings, like reference numerals designate identical or similar parts throughout the several views. Wherein:

fig. 1 is a schematic view showing a structure of a battery according to an exemplary embodiment;

fig. 2 is a schematic diagram illustrating a structure of a battery according to another view angle of an exemplary embodiment;

FIG. 3 is a schematic diagram of a cell structure according to an exemplary embodiment;

FIG. 4 is a schematic illustration of a connection face with a plurality of protrusions formed thereon, according to an example embodiment;

FIG. 5 is an enlarged schematic view of a connection surface with a plurality of protrusions formed thereon, according to an exemplary embodiment;

FIG. 6 is a schematic diagram of an insulator and post assembly according to an exemplary embodiment;

FIG. 7 is a schematic illustration of a construction of an insulation snap-fit according to an exemplary embodiment;

fig. 8 is a schematic diagram showing a structure after an insulator is opened according to an exemplary embodiment.

The reference numerals are explained as follows:

10. a battery;

100. a battery cell; 110. a cell body; 120. a tab; 121. a positive electrode tab; 122. a negative electrode tab;

200. a pole assembly; 210. a first pole assembly; 211. a first connection terminal; 220. a second post assembly; 221. a second connection terminal; 230. a connection surface; 240. a protrusion;

300. a battery case; 301. a first major surface; 302. a second major surface; 303. a first minor surface; 304. a second minor surface; 310. a first housing member; 320. a second housing member; 331. a first recess; 332. a second recess; 340. a liquid injection hole;

410. a first insulating member; 420. a second insulating member; 430. a first base plate; 440. a first buckling part.

Detailed Description

The technical solutions in the exemplary embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the exemplary embodiments of the present disclosure. The example embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure, and it is therefore to be understood that various modifications and changes may be made to the example embodiments without departing from the scope of the present disclosure.

In the description of the present disclosure, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance unless explicitly specified or limited otherwise; the term "plurality" refers to two or more than two; the term "and/or" includes any and all combinations of one or more of the associated listed items. In particular, references to "the/the" object or "an" object are likewise intended to mean one of a possible plurality of such objects.

Unless specified or indicated otherwise, the terms "connected," "fixed," and the like are to be construed broadly and are, for example, capable of being fixedly connected, detachably connected, or integrally connected, electrically connected, or signally connected; "coupled" may be directly coupled or indirectly coupled through intermediaries. The specific meaning of the terms in the present disclosure may be understood by those skilled in the art according to the specific circumstances.

Further, in the description of the present disclosure, it should be understood that the terms "upper", "lower", "inner", "outer", and the like, as described in the example embodiments of the present disclosure, are described with the angles shown in the drawings, and should not be construed as limiting the example embodiments of the present disclosure. It will also be understood that in the context of an element or feature being connected to another element(s) "upper," "lower," or "inner," "outer," it can be directly connected to the other element(s) "upper," "lower," or "inner," "outer," or indirectly connected to the other element(s) "upper," "lower," or "inner," "outer" via intervening elements.

The embodiment of the present utility model provides a battery, as shown in fig. 1 to 5, the battery 10 includes a battery cell 100 and a terminal assembly 200, the battery cell 100 including a battery cell main body 110 and a tab 120 led out from an end of the battery cell main body 110; the pole assembly 200 has a connection surface 230 facing the tab 120, and a plurality of protrusions 240 facing the tab 120 are formed on the connection surface 230, and the plurality of protrusions 240 are welded with the tab 120 by resistance welding.

Wherein, the total area of orthographic projection of the plurality of protrusions 240 on the connecting surface 230 is x, the tab 120 comprises a plurality of single-sheet tabs stacked in the thickness direction, the thickness of the single-sheet tab is a, and a/x is not less than 0.06 and not more than 0.5 (unit: μm/mm) ² ) The ratio of a/x is, for example, 0.06, 0.08, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, etc.

In the battery 10 provided by the utility model, the connection surface 230 of the pole assembly 200 and the pole lug 120, which is welded by resistance welding, is provided with a plurality of protrusions 240, and the protrusions 240 and the pole lug 120 are welded by resistance welding; when the thickness of the single-layer pole piece is too large and the total area of orthographic projection of the plurality of protrusions 240 on the connecting surface 230 is too small, if a large current is selected for resistance welding, a large amount of heat generated at the plurality of protrusions 240 can occur, and the sealing performance of sealing elements around the pole assembly 200 and the reliability of other assemblies can be affected by high temperature caused by the large amount of heat; if the resistance welding is performed with a small current, a predetermined welding effect is not easily achieved between the tab 120 and the plurality of protrusions 240; the ratio of the thickness a of the single lug to the total orthographic projection area x of the plurality of protrusions 240 on the connecting surface 230 is 0.06-0.5, so that the problem of large heating value caused by large current selected by resistance welding is avoided, high temperature caused by large heating value is avoided, and the sealing performance of sealing elements around the pole assembly 200 and the reliability of other assemblies are ensured; meanwhile, the phenomenon that the preset welding effect cannot be achieved between the tab 120 and the plurality of protrusions 240 due to the fact that small current is selected for resistance welding is avoided, and the welding effect of the tab 120 and the pole assembly 200 is guaranteed.

It should be noted that the battery 10 includes the cell 100 and an electrolyte, and is capable of performing a minimum unit of electrochemical reaction such as charge/discharge. The battery cell 100 refers to a unit formed by winding or laminating a stacked portion. As shown in fig. 3, the battery cell 100 includes a cell main body 110, a positive electrode tab 121, and a negative electrode tab 122. The cell main body 110 has a first electrode sheet, a second electrode sheet opposite to the first electrode sheet, and a diaphragm sheet disposed between the first electrode sheet and the second electrode sheet, which are stacked on each other, so that a plurality of pairs of the first electrode sheet and the second electrode sheet are stacked to form a stacked type cell. The positive electrode tab 121 is connected to the first electrode sheet, and the negative electrode tab 122 is connected to the second electrode sheet. Alternatively, the battery cell 100 may be a winding type battery cell, that is, a first pole piece, a second pole piece opposite to the first pole piece, and a diaphragm disposed between the first pole piece and the second pole piece are wound to obtain a winding type battery cell.

In one embodiment, as shown in fig. 1 and 2, the battery 10 may be a square battery, that is, the battery 10 may be a quadrangular battery, and a quadrangular battery mainly refers to a prismatic shape, but it is not strictly limited whether each side of the prism is necessarily a strictly straight line, and corners between sides are not necessarily right angles, and may be arc transitions. The quadrangular type battery can be a laminated battery, is convenient to group, and can be processed to obtain a battery with longer length.

In one embodiment, only one cell 100 is disposed within the battery 10. The positive electrode tab 121 and the negative electrode tab 122 are located at two ends of the cell main body 110 in the length direction. By arranging only one battery cell 100 in the battery case 300, the space utilization rate of the battery 10 is improved, and the assembly efficiency of the battery cell 100 is improved. Of course, a plurality of electric cells 100 may be disposed in the battery case 300, and the plurality of electric cells 100 may be connected in series or in parallel, and the positive electrode tab 121 and the negative electrode tab 122 of the plurality of electric cells 100 may be respectively led out through the electrode post assembly 200, which is not limited in the present utility model.

In one embodiment, the number of layers of the single tab 120, which is stacked, is b, and 0.03.ltoreq.a/b.ltoreq.0.5 (unit: μm/layer), and the ratio of a/b is, for example, 0.03, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, etc. When the tab 120 and the post assembly 200 are welded by resistance welding, when the single tab is too thick, the number of layers of the single tab is too small, resulting in a low energy density of the battery 10; when the single tab is too thin, the number of layers of the single tab is too large, resulting in a large capacity of the battery 10, and insufficient overcurrent capability of the tab 120 is likely to occur. The utility model avoids the problem of lower energy density of the battery 10 caused by excessively thick single-sheet tabs, avoids the problem of insufficient overcurrent capacity of the tab 120 caused by excessively large capacity of the battery 10 caused by excessively thin single-sheet tabs, and ensures the energy density of the battery 10 and the overcurrent capacity of the tab 120 by making the ratio of the thickness a of the single-sheet tab to the number b of the single-sheet tab be 0.03-0.5.

In one embodiment, the thickness a of the single tab is 3 μm to 15 μm, for example, 3 μm, 5 μm, 7 μm, 9 μm,10 μm, 13 μm, 15 μm, etc., which is not specifically exemplified herein. When the tab 120 and the pole assembly 200 are welded by resistance welding, if the thickness of the tab 120 is too thick, a larger current is required to melt the tab 120, so that the tab 120 has a cold joint risk and the resistance welding efficiency is affected; if the thickness of the tab 120 is too thin, the resistance welding is easy to break down the tab 120, so that the tab 120 is in risk of penetration; according to the utility model, the thickness a of the single lug is 3-15 mu m, so that the problem that the lug 120 is at a cold joint risk caused by the too thick lug 120 is avoided when the lug 120 and the pole assembly 200 are welded by resistance welding, the problem that the lug 120 is broken down by resistance welding caused by the too thin lug 120 is avoided, and the reliability and the welding efficiency of resistance welding of the lug 120 and the pole assembly 200 are improved. Of course, the thickness a of the single tab may be less than 3 μm or greater than 15 μm, which is not limited in the present utility model.

In one embodiment, the battery cell 100 includes a plurality of tabs 120, as shown in fig. 3, the plurality of tabs 120 includes a positive tab 121 and a negative tab 122, and the positive tab 121 and the negative tab 122 are respectively led out from opposite ends of the battery cell body 110 along the length direction of the battery cell 100. The battery cell 100 includes a plurality of post assemblies 200, as shown in fig. 1, the plurality of post assemblies 200 includes a first post assembly 210 and a second post assembly 220, the first post assembly 210 has a first connection surface facing the positive electrode tab 121, a plurality of first protrusions facing the positive electrode tab 121 are formed on the first connection surface, and the plurality of first protrusions are welded with the positive electrode tab 121; the second post assembly 220 has a second connection surface facing the negative electrode tab 122, and a plurality of second protrusions facing the negative electrode tab 122 are formed on the second connection surface and welded with the negative electrode tab 122.

The positive electrode tab 121 includes a plurality of positive electrode single-piece tabs stacked in the thickness direction, and the thickness of the positive electrode single-piece tabs is 8 μm to 15 μm, for example, 8 μm, 9 μm,10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, and the like, and the present utility model is not limited to this. Because the positive electrode tab 121 is usually an aluminum tab, the melting point of the aluminum tab is lower than that of the copper tab, so that the thickness of the positive electrode single-piece tab is made to be 8-15 μm, the problem that the resistance welding breaks down the positive electrode single-piece tab due to the fact that the thickness of the aluminum positive electrode single-piece tab is too thin is avoided, and the reliability of resistance welding of the positive electrode tab 121 and the electrode post assembly 200 is improved. Of course, the thickness of the positive electrode single tab can be smaller than 8 μm or larger than 15 μm, which is not limited by the present utility model.

The thickness of the positive electrode single tab is 10 μm to 13 μm, for example, 10 μm, 11 μm, 12 μm, 13 μm, etc., and the present utility model is not limited to this. By making the thickness of the single-piece tab of the positive electrode 10 μm to 13 μm, the problem that the single-piece tab of the positive electrode is broken down by resistance welding due to the too thin thickness of the single-piece tab of the positive electrode, and the reliability of resistance welding between the single-piece tab of the positive electrode 121 and the first electrode post assembly 210 is further improved.

Wherein, the thickness of a plurality of positive pole monolithic utmost point ears is the same. Through making the thickness of a plurality of positive pole monolithic tabs the same, when anodal tab 121 welds with first utmost point post subassembly 210, can guarantee the welding effect between a plurality of positive pole monolithic tabs and the first utmost point post subassembly 210, avoid because the thickness of a plurality of positive pole monolithic tabs is different to lead to appearing some anodal monolithic tabs and appear resistance welding and break down anodal monolithic tab or some anodal monolithic tabs have the problem of rosin joint risk. Of course, the thicknesses of the plurality of single-piece tabs of the positive electrode can also be different, and the utility model is not limited to this.

The negative electrode tab 122 includes a plurality of negative electrode single-piece tabs stacked in the thickness direction, and the thickness of the negative electrode single-piece tabs is 3 μm to 8 μm, for example, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, and the like, and the present utility model is not limited to this. Because the negative electrode tab 122 is usually a copper tab, the melting point of the copper tab is higher than that of the aluminum tab, so that the thickness of the negative electrode single-sheet tab is 3-8 μm, so that the thickness of the negative electrode single-sheet tab is thinner than that of the positive electrode single-sheet tab, the problem that the negative electrode single-sheet tab is in cold joint risk due to the fact that the negative electrode single-sheet tab is too thick is avoided, and the reliability of resistance welding of the negative electrode tab 122 and the second electrode column assembly 220 is improved. Of course, the thickness of the negative electrode single tab can be smaller than 3 μm or larger than 8 μm, and the utility model is not limited thereto.

The thickness of the negative electrode single tab is 4 μm to 6 μm, for example, 4 μm, 5 μm, 6 μm, etc., and the present utility model is not limited thereto. The thickness of the negative single tab is 6 μm-6 μm, so that the problem that the negative single tab is in the risk of cold welding caused by the excessive thickness of the negative single tab is further avoided, and the reliability of the resistance welding of the negative tab 122 and the second pole component 220 is further improved.

Wherein, the thickness of a plurality of negative pole monolithic tabs is the same. Through making the thickness of a plurality of negative pole monolithic tabs the same, when negative pole tab 122 welds with second post subassembly 220, can guarantee the welding effect between a plurality of negative pole monolithic tabs and the second post subassembly 220, avoid because the thickness difference of a plurality of negative pole monolithic tabs leads to appearing the problem that the resistance welding breakdown negative pole monolithic tab or part negative pole monolithic tab exist the rosin joint risk of appearance of part negative pole monolithic tab. Of course, the thicknesses of the plurality of negative electrode single-sheet tabs can also be different, and the utility model is not limited to this.

In one embodiment, as shown in fig. 6, the first pole assembly 210 includes two first connection terminals 211 and the second pole assembly 220 includes two second connection terminals 221.

Specifically, as shown in fig. 6, the first tab assembly 210 includes two first connection terminals 211, the two first connection terminals 211 being disposed at intervals in the width direction of the battery case 300 and each having a first connection surface, and a plurality of first protrusions being formed on the first connection surfaces of the two first connection terminals 211.

The areas of orthographic projections of the first protrusions on the first connection surface of the first connection terminal 211 are the same, so that the overcurrent areas of the first protrusions are the same, and the welding effect of the first connection terminal 211 and the positive electrode tab 121 is further ensured. Of course, the area of orthographic projection of the plurality of first protrusions on the first connection surface of the first connection terminal 211 may also be different.

The number of the first protrusions on the two first connection terminals 211 may be the same, so that when the positive electrode tab 121 is welded to the two first connection terminals 211, the welding effect of the positive electrode tab 121 and the two first connection terminals 211 can be ensured. Of course, the number of the plurality of first protrusions on the two first connection terminals 211 may also be different.

Specifically, as shown in fig. 6, the second post assembly 220 includes two second connection terminals 221, the two second connection terminals 221 are disposed at intervals in the width direction of the battery case 300, and each have a second connection surface, and a plurality of second protrusions are formed on the second connection surfaces of the two second connection terminals 221.

The areas of orthographic projections of the second protrusions on the second connection surface of the second connection terminal 221 on the second connection terminal 221 are the same, so that the overcurrent areas of the second protrusions are the same, and the welding effect of the second connection terminal 221 and the negative electrode tab 122 is further ensured. Of course, the area of orthographic projection of the plurality of second protrusions on the second connection surface of the second connection terminal 221 may also be different.

The number of the second protrusions on the two second connection terminals 221 may be the same, so that when the negative electrode tab 122 is welded to the two second connection terminals 221, the welding effect of the negative electrode tab 122 and the two second connection terminals 221 can be ensured. Of course, the number of the plurality of second protrusions on the two second connection terminals 221 may also be different.

In one embodiment, the number of the first protrusions is the same as that of the second protrusions, so that parameters such as welding current and the like of resistance welding can be conveniently adjusted during welding, and welding probability is improved. Of course, the number of first protrusions and second protrusions may also be different.

In one embodiment, as shown in fig. 1 and 6, the battery 10 further includes: the battery case 300, the first insulating member 410, and the second insulating member 420.

As shown in fig. 1 and 2, the battery case 300 includes a first case member 310 and a second case member 320, the first case member 310 being formed with a first large surface 301, the second case member 320 being formed with a second large surface 302, the first large surface 301 being disposed opposite to the second large surface 302; a first recess 331 and a second recess 332 are provided on both ends of the second large surface 302 in the length direction of the battery case 300; the battery cell 100 is disposed in the battery case 300;

as shown in fig. 2, the battery case 300 further includes two first small surfaces 303 and two second small surfaces 304 disposed opposite to each other, the first small surfaces 303 having an area larger than that of the second small surfaces 304, and the first large surfaces 301 and the second large surfaces 302 each having an area larger than that of the first small surfaces 303; wherein the first recess 331 and the second recess 332 intersect two first facets 303 and one second facet 304.

In one embodiment, the first housing member 310 is a cover plate, the second housing member 320 is formed with a receiving space, and the battery cell 100 is located in the receiving space. The second housing member 320 is of an integrally formed structure, such as by stamping.

Wherein, the first insulator 410 is connected with the first pole assembly 210, and the second insulator 420 is connected with the second pole assembly 220; the first insulator 410 at least partially coincides with the orthographic projection of the first recess 331 on the first large surface 301, and the second insulator 420 at least partially coincides with the orthographic projection of the second recess 332 on the first large surface 301, i.e., the first insulator 410 is located in a first step of the battery case 300 formed at the first recess 331, and the second insulator 420 is located in a second step of the battery case 300 formed at the second recess 332; the surface of the first step part facing the cover plate forms limit constraint on the first insulating piece 410, and the surface of the second step part facing the cover plate forms limit constraint on the second insulating piece 420, so that the overall strength of the first insulating piece 410 and the second insulating piece 420 is improved, and the situation that the local positions of the first insulating piece 410 and the second insulating piece 420 are staggered due to bending deformation of the battery case 300 when local stress is applied is further avoided.

Meanwhile, since the first insulating member 410 is disposed opposite to the first pole assembly 210, the second insulating member 420 is disposed opposite to the second pole assembly 220, when the plurality of batteries 10 are stacked in the thickness direction to form a group, the first pole assembly 210 and the second pole assembly 220 of the adjacent battery 10 can be separated into the corresponding first recess 331 and the second recess 332, so that the first recess 331 and the second recess 332 of the adjacent battery 10 are configured to respectively yield the first pole assembly 210 and the second pole assembly 220 of the other battery 10, thereby avoiding collision with the pole assembly 200, and improving the space utilization rate when the batteries 10 are grouped.

As shown in fig. 7 and 8, the first insulating member 410 includes a first bottom plate 430 and a first fastening portion 440, the first fastening portion 440 is located on a side of the first bottom plate 430 close to the second housing member 320, the first connection surface is located between the first bottom plate 430 and the first fastening portion 440, and at least a portion of the positive tab 121 welded to the first protrusion is located between the first bottom plate 430 and the first fastening portion 440. The welding part is protected by the insulating part, so that the problems of breakage and the like of the welding part due to external force impression are avoided; meanwhile, the welding part of the tab 120 and the pole assembly 200 is positioned between the bottom plate and the buckling part, so that when welding slag falls off at the welding part, the welding slag can be contained between the bottom plate and the buckling part, the situation that the welding is directly fallen into the battery core main body 110 to cause short circuit between pole pieces is avoided, and the safety of the battery 10 is improved.

The second insulating member 420 includes a second bottom plate and a second fastening portion, the second fastening portion is located on a side of the second bottom plate near the second housing member 320, the second connecting surface is located between the second bottom plate and the second fastening portion, and at least a portion of the negative electrode tab 122 welded with the second protrusion is located between the second bottom plate and the second fastening portion. The welding part is protected by the insulating part, so that the problems of breakage and the like of the welding part due to external force impression are avoided; meanwhile, the welding part of the tab 120 and the pole assembly 200 is positioned between the bottom plate and the buckling part, so that when welding slag falls off at the welding part, the welding slag can be contained between the bottom plate and the buckling part, the situation that the welding is directly fallen into the battery core main body 110 to cause short circuit between pole pieces is avoided, and the safety of the battery 10 is improved.

Wherein, the bottom plate of insulating part and buckling part joint. The bottom plate of the insulating piece is clamped with the buckling part, the insulating piece can be opened and closed, when the lug 120 and the pole assembly 200 are welded, the bottom plate and the buckling part are in an opened state, and the lug 120 extends into the space between the bottom plate and the buckling part and is welded with the pole; after the tab 120 is welded to the post assembly 200, the bottom plate is engaged with the engaging portion. The utility model does not limit the clamping structure of the bottom plate of the insulating piece and the buckling part, and the clamping structure can be the matching of the clamping convex and the clamping hole, and can also be the matching of the clamping column and the clamping seat, and all the changes on the clamping structure belong to the protection scope of the utility model.

In one embodiment, as shown in fig. 1, a liquid injection hole 340 is provided in the first case member 310, and electrolyte is injected into the cell 100 through the liquid injection hole 340. The liquid injection hole 340 is sealed by a sealing structure.

In one embodiment, the length of the cell 10 is L,400mm L.ltoreq.2800 mm, the width of the cell 10 is W, the height of the cell 10 is H,2 W.ltoreq.L.ltoreq.80W, and/or 0.5 H.ltoreq.W.ltoreq.20H.

Further, W is more than or equal to 80mm and less than or equal to 200mm, H is more than or equal to 10mm and less than or equal to 100mm.

Preferably, 4 W.ltoreq.L.ltoreq.25W, and/or 2 H.ltoreq.W.ltoreq.10H.

The battery 10 in the above-described embodiment is large in the ratio of the length to the width of the battery 10, and further, in the ratio of the width to the height of the battery 10, while securing sufficient energy density.

In one embodiment, the length of the battery 10 is L, the width of the battery 10 is W, and 4W is equal to or less than L is equal to or less than 7W, i.e., the ratio of the length to the width of the battery 10 in this embodiment is larger, so as to increase the energy density of the battery 10 and facilitate the subsequent formation of the battery pack.

In one embodiment, the height of the battery 10 is H,3 H.ltoreq.W.ltoreq.7H, and the ratio of the width to the height of the battery 10 is large, which is also convenient in formation while ensuring sufficient energy density.

Alternatively, the length of the battery 10 may be 800mm to 1800mm, the width of the battery 10 may be 80mm to 180mm, and the height of the battery 10 may be 15mm to 35mm.

Embodiments of the present disclosure also provide a battery pack including the battery 10 described above.

The battery pack of the embodiment of the disclosure comprises a battery 10, wherein a plurality of protrusions 240 are arranged on a connecting surface 230 of a pole assembly 200 of the battery 10 and a pole lug 120 which are welded by resistance welding, and the protrusions 240 and the pole lug 120 are welded by resistance welding; when the thickness of the single-layer pole piece is too large and the total area of orthographic projection of the plurality of protrusions 240 on the connecting surface 230 is too small, if a large current is selected for resistance welding, a large amount of heat generated at the plurality of protrusions 240 can occur, and the sealing performance of sealing elements around the pole assembly 200 and the reliability of other assemblies can be affected by high temperature caused by the large amount of heat; if the resistance welding is performed with a small current, a predetermined welding effect is not easily achieved between the tab 120 and the plurality of protrusions 240; the ratio of the thickness a of the single lug to the total orthographic projection area x of the plurality of protrusions 240 on the connecting surface 230 is 0.06-0.5, so that the problem of large heating value caused by large current selected by resistance welding is avoided, high temperature caused by large heating value is avoided, and the sealing performance of sealing elements around the pole assembly 200 and the reliability of other assemblies are ensured; meanwhile, the fact that small current is selected for resistance welding is avoided, the preset welding effect cannot be achieved between the lug 120 and the plurality of protrusions 240, and the welding effect of the lug 120 and the pole assembly 200 is guaranteed.

In one embodiment, the battery pack is a battery module or a battery pack.

The battery module includes a plurality of batteries 10, and the battery module may further include an end plate and a side plate for fixing the plurality of batteries 10.

The plurality of batteries 10 may be disposed in the battery case after forming the battery module, and may be fixed by the end plate and the side plate. The plurality of cells 10 may be disposed directly in the cell case, i.e., without grouping the plurality of cells, at which time the end plates and side plates may be removed.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the utility model disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the utility model following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. The specification and example embodiments are to be considered exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It is to be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims (15)

1. A battery, comprising:

the battery cell (100), the battery cell (100) comprises a battery cell main body (110) and a tab (120) led out from the end part of the battery cell main body (110);

a pole assembly (200), wherein the pole assembly (200) is provided with a connecting surface (230) facing the pole lug (120), a plurality of protrusions (240) facing the pole lug (120) are formed on the connecting surface (230), and the protrusions (240) are welded with the pole lug (120) in a resistance welding way;

the total area of orthographic projection of the plurality of protrusions (240) on the connecting surface (230) is x, the lug (120) comprises a plurality of single-chip lugs which are stacked in the thickness direction, and the thickness of the single-chip lugs is a, and a/x is more than or equal to 0.06 and less than or equal to 0.5.

2. The battery according to claim 1, wherein the number of layers of the single tab in the laminated arrangement of the tabs (120) is b, 0.03-0.5.

3. The battery according to claim 1, wherein the thickness a of the single tab is 3 μm to 15 μm.

4. The battery according to claim 1, wherein the cell (100) includes a plurality of the tabs (120), the plurality of the tabs (120) including a positive electrode tab (121) and a negative electrode tab (122), the positive electrode tab (121) and the negative electrode tab (122) being respectively led out from opposite ends of the cell main body (110) along a length direction of the cell (100);

the battery cell (100) comprises a plurality of pole assemblies (200), the plurality of pole assemblies (200) comprise a first pole assembly (210) and a second pole assembly (220), the first pole assembly (210) is provided with a first connecting surface facing the positive pole lug (121), a plurality of first bulges facing the positive pole lug (121) are formed on the first connecting surface, and the plurality of first bulges and the positive pole lug (121) are welded together; the second pole assembly (220) is provided with a second connecting surface facing the negative pole lug (122), a plurality of second bulges facing the negative pole lug (122) are formed on the second connecting surface, and the second bulges and the negative pole lug (122) are welded together.

5. The battery according to claim 4, wherein the positive electrode tab (121) includes a plurality of positive electrode single-piece tabs stacked in a thickness direction, and the thickness of the positive electrode single-piece tabs is 8 μm to 15 μm.

6. The battery of claim 5, wherein the thickness of the positive monolithic tab is 10 μm to 13 μm.

7. The battery according to claim 5, wherein the negative electrode tab (122) includes a plurality of negative electrode single-piece tabs stacked in a thickness direction, and the negative electrode single-piece tabs have a thickness of 3 μm to 8 μm.

8. The battery of claim 7, wherein the negative monolithic tab has a thickness of 4 μιη to 6 μιη.

9. The battery according to claim 4, wherein the positive electrode tab (121) includes a plurality of positive electrode single-piece tabs stacked in a thickness direction, the thickness of the plurality of positive electrode single-piece tabs being the same; and/or, the negative electrode tab (122) comprises a plurality of negative electrode single-sheet tabs stacked in the thickness direction, and the thicknesses of the plurality of negative electrode single-sheet tabs are the same.

10. The battery according to claim 4, wherein the first terminal assembly (210) includes two first connection terminals (211), the two first connection terminals (211) being disposed at intervals in the width direction of the battery cell (100) and each having the first connection surface, the first connection surfaces of the two first connection terminals (211) each having a plurality of the first protrusions formed thereon; and/or the number of the groups of groups,

the second pole assembly (220) comprises two second connecting terminals (221), the two second connecting terminals (221) are arranged at intervals in the width direction of the battery cell (100), each second connecting terminal is provided with a second connecting surface, and a plurality of second bulges are formed on the second connecting surfaces of the two second connecting terminals (221).

11. The battery of claim 4, wherein the area of orthographic projection of the plurality of first protrusions on the first connection surface is the same; and/or the areas of orthographic projections of the second bulges on the second connecting surface are the same.

12. The battery of claim 4, wherein the first protrusions are the same number as the second protrusions.

13. The battery of claim 4, wherein the battery further comprises:

a battery case (300), the battery case (300) comprising a first case member (310) and a second case member (320), the first case member (310) being formed with a first large surface (301), the second case member (320) being formed with a second large surface (302), the first large surface (301) being disposed opposite to the second large surface (302); along the length direction of the battery shell (300), a first concave recess (331) and a second concave recess (332) are arranged on two ends of the second large surface (302); the electric core (100) is arranged in the battery shell (300);

a first insulator (410) and a second insulator (420), the first insulator (410) being connected to the first pole assembly (210), the second insulator (420) being connected to the second pole assembly (220); the first insulator (410) at least partially coincides with an orthographic projection of the first recess (331) on the first large surface (301), and the second insulator (420) at least partially coincides with an orthographic projection of the second recess (332) on the first large surface (301).

14. The battery according to claim 13, wherein the first insulating member (410) includes a first bottom plate (430) and a first fastening portion (440), the first fastening portion (440) being located on a side of the first bottom plate (430) close to the second case member (320), the first connection surface being located between the first bottom plate (430) and the first fastening portion (440), and at least a portion of the positive electrode tab (121) welded to the first protrusion being located between the first bottom plate (430) and the first fastening portion (440); and/or the number of the groups of groups,

the second insulating piece (420) comprises a second bottom plate and a second buckling part, the second buckling part is located on one side, close to the second shell piece (320), of the second bottom plate, the second connecting surface is located between the second bottom plate and the second buckling part, and at least the part, welded with the second protrusion, of the negative electrode tab (122) is located between the second bottom plate and the second buckling part.

15. The battery of claim 1, wherein the battery is a quadrangular type battery.