CN217848246U

CN217848246U - Battery and battery pack

Info

Publication number: CN217848246U
Application number: CN202222040864.9U
Authority: CN
Inventors: 马豪; 王娟; 张勇杰; 李慧珍; 王留杰
Original assignee: China Lithium Battery Technology Co Ltd
Current assignee: China Lithium Battery Technology Co Ltd
Priority date: 2022-08-03
Filing date: 2022-08-03
Publication date: 2022-11-18
Anticipated expiration: 2032-08-03

Abstract

The utility model relates to a battery technology field provides a battery and group battery. The battery comprises a battery cell, wherein the battery cell comprises a battery cell main body and a lug, and the lug extends out of the battery cell main body; the cover plate assembly is welded with the lug to form a welding mark; wherein, the area of welding the seal is a, and the area that the utmost point ear has the surface of welding the seal is b, and 0.2% is more than or equal to a/b and is less than or equal to 20%, not only can guarantee the area of overflowing of utmost point ear, avoids the too big damage utmost point ear of temperature rise, and can avoid welding the seal area too big, causes utmost point ear fracture or damages other external structures to this improves welding quality, thereby improves the safety in utilization ability of battery.

Description

Battery and battery pack

Technical Field

The utility model relates to a battery technology field especially relates to a battery and group battery.

Background

In the related art, the tab of the battery cell is connected with the pole assembly through the adapter sheet, and the tab and the adapter sheet are generally connected by welding, so that the tab can be damaged during welding or the welding quality is poor, and the connection reliability is affected.

SUMMERY OF THE UTILITY MODEL

The utility model provides a battery and group battery to improve the performance of battery.

According to an aspect of the present invention, there is provided a battery, including:

the battery cell comprises a battery cell main body and a lug, wherein the lug extends out of the battery cell main body;

the cover plate assembly is welded with the lug to form a welding mark;

wherein the area of the welding mark is a, the area of the surface of the tab with the welding mark is b, and a/b is more than or equal to 0.2% and less than or equal to 20%.

The utility model discloses the battery includes electric core and apron subassembly, electric core includes electric core main part and the utmost point ear that extends out by electric core main part, it welds the seal to be formed with the apron subassembly through utmost point ear, and the area that welds the seal is an, the area that utmost point ear has the surface that welds the seal is b,0.2% is less than or equal to an/b and is less than or equal to 20%, not only can guarantee the flow area of utmost point ear, avoid the too big damage utmost point ear of temperature rise, and can avoid welding the seal area too big, cause utmost point ear fracture or damage other exterior structure, improve welding quality with this, thereby improve the safety in service performance of battery.

According to another aspect of the present invention, there is provided a battery pack including the above battery.

The utility model discloses the group battery includes the battery, the battery includes electric core and apron subassembly, electric core includes electric core main part and the utmost point ear that extends out by electric core main part, through be formed with on utmost point ear and weld the seal, and the area of welding the seal is an, the area that utmost point ear has the surface of welding the seal is b,0.2% is less than or equal to an/b and is less than or equal to 20%, not only can guarantee the flow area of utmost point ear, avoid the too big damage utmost point ear of temperature rise, and can avoid welding the seal area too big, cause utmost point ear fracture or damage other exterior structure, improve welding quality with this, thereby improve the safety in service performance of group battery.

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 so as to emphasize and clearly illustrate the technical features of the present disclosure. In addition, the relevant elements or components may be arranged differently as is known in the art. Further, in the drawings, like reference characters designate the same or similar parts throughout the several views. Wherein:

FIG. 1 is an exploded schematic view of a battery according to an exemplary embodiment;

FIG. 2 is a schematic diagram of a portion of a battery according to an exemplary embodiment;

FIG. 3 is a schematic diagram illustrating a partial structure of a battery according to another exemplary embodiment;

fig. 4 is a schematic structural view showing a tab of a battery according to a first exemplary embodiment;

fig. 5 is a schematic view showing a structure of a tab of a battery according to a second exemplary embodiment;

fig. 6 is a structural view showing a tab of a battery according to a third exemplary embodiment;

fig. 7 is a partial structural schematic view illustrating a battery pack according to an exemplary embodiment.

The reference numerals are explained below:

10. an electric core; 11. a cell main body; 12. a tab; 121. welding and printing; 20. a cover plate; 30. a pole assembly; 40. a patch; 50. a housing member; 60. a bus bar; 61. a high voltage output terminal; 70. high-voltage copper bars.

Detailed Description

The technical solutions in the exemplary embodiments of the present disclosure will be clearly and completely described below with reference to the 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, so it should 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, unless explicitly specified or limited otherwise, 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; the term "plurality" means two or more; the term "and/or" includes any and all combinations of one or more of the associated listed items. In particular, reference to "the" object or "an" object is also intended to mean one of many such objects possible.

The terms "connected," "secured," and the like are to be construed broadly and encompass, for example, a fixed connection, a removable connection, an integral connection, an electrical connection, or a signal connection; "connected" may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present disclosure can be understood as a specific case by a person skilled in the art.

Further, in the description of the present disclosure, it is to be understood that the directional words "upper", "lower", "inner", "outer", etc., which are described in the exemplary embodiments of the present disclosure, are described at the angles shown in the drawings, and should not be construed as limiting the exemplary embodiments of the present disclosure. It will also be understood that, in the context of a connection between one element or feature and another element(s), "on," "under," or "inside" or "outside," it can be directly connected to the other element(s) "on," "under" or "inside" or "outside," or indirectly connected to the other element(s) "on," "under" or "inside" or "outside" through intervening elements.

An embodiment of the present invention provides a battery, please refer to fig. 1 to fig. 6, the battery includes: the battery cell 10 includes a battery cell main body 11 and tabs 12, where the tabs 12 extend from the battery cell main body 11; a cover plate assembly welded with the tab 12 to form a weld 121; wherein the area of the welding print 121 is a, the area of the surface of the tab 12 with the welding print 121 is b, and a/b is more than or equal to 0.2% and less than or equal to 20%.

The utility model discloses a battery of an embodiment includes electric core 10 and apron subassembly, electric core 10 includes electric core main part 11 and the utmost point ear 12 that extends out by electric core main part 11, be formed with welding seal 121 through utmost point ear 12 and apron subassembly welding, and the area of welding seal 121 is an, the area that utmost point ear 12 has the surface of welding seal 121 is b,0.2% a/b is not more than or equal to 20%, not only can guarantee the area of overflowing of utmost point ear 12, avoid the too big damage utmost point ear 12 of temperature rise, and can avoid welding seal 121 area too big, cause utmost point ear 12 fracture or damage other exterior structure, thereby improve welding quality, thereby improve the safety in service performance of battery.

It should be noted that the tab 12 may be welded to the cover plate assembly, so as to form a weld mark 121 on the tab 12, thereby ensuring the connection stability of the tab 12 and the cover plate assembly. While the surface of the tab 12 having the weld mark 121 may be considered as the surface of the tab 12 opposite to the cover plate assembly, or the surface of the tab 12 having the weld mark 121 may be considered as the surface of the tab 12 facing away from the cover plate assembly, where the weld mark 121 is formed on the tab 12 is emphasized. For example, the side of the tab 12 facing the cover plate assembly is an upper surface, in which case the welding mark 121 is formed on the upper surface, the area of the welding mark 121 is a, the upper surface of the tab 12 is b, and 0.2% a/b is less than or equal to 20%. The welding seal 121 is formed by welding the tab 12 and the cover plate assembly to connect the tab 12 and the cover plate assembly, so that the cover plate assembly serves as an electrode leading-out end of the battery cell 10, and reliable overcurrent capacity between the tab 12 and the cover plate assembly can be ensured, thereby ensuring the connection stability of the tab 12 and the cover plate assembly. The cover plate assembly may include a cover plate 20 and a pole assembly 30, the pole assembly 30 is disposed on the cover plate 20, and the tab 12 may be electrically connected with the pole assembly 30.

When the ratio of the area a of the welding seal 121 to the surface b of the tab 12 with the welding seal 121 is less than 0.2%, the overcurrent capacity of the tab 12 and the cover plate assembly is small, so that the temperature rise at the joint of the tab 12 and the cover plate assembly is high, even fusing occurs, the overcurrent capacity requirement of the battery is not met, namely, the charging and discharging capacity requirement of the battery is met, and even the safety risk occurs. When the ratio of the area a of the welding mark 121 to the surface b of the tab 12 with the welding mark 121 is greater than 20%, the overcurrent capacity of the tab 12 and the cover plate assembly is large, and larger energy is needed in the welding process, so that the tab 12 is easily broken.

In one embodiment, the a/b is more than or equal to 1.8% and less than or equal to 10.6%, and on the basis of ensuring the overcurrent capacity of the tab 12 and the cover plate assembly, the problem that the tab 12 is damaged or other structures are damaged due to large energy in the welding process of the tab 12 can be avoided.

In one embodiment, the ratio of the area a of the weld mark 121 to the surface b of the tab 12 having the weld mark 121 may be 0.2%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 3%, 4%, 5%, 8%, 9%, 10%, 10.5%, 10.6%, 10.8%, 11%, 13%, 14%, 15%, 18%, 19%, 20%, or the like.

In one embodiment, as shown in fig. 4, the tab 12 extends from the cell body 11 along the first direction a; wherein, along first direction A, weld the interval setting between seal 121 and the outward flange of utmost point ear 12, along the second direction B of perpendicular to first direction A, weld the interval setting between seal 121 and the outward flange of utmost point ear 12 to can make and weld seal 121 to be located utmost point ear 12's middle part, can not cause the damage to utmost point ear 12 when guaranteeing to weld, and can guarantee utmost point ear 12 and apron subassembly's welding stability.

In one embodiment, the tab 12 extends from the cell body 11 along the first direction a; in the first direction a, the welding seal 121 and the outer edge of the tab 12 are spaced from each other, so that a certain distance can be reserved between the welding seal 121 and the cell main body 11, and a certain distance can be reserved between the welding seal 121 and the end portion of the tab 12 far away from the cell main body 11, thereby preventing the cell main body 11 from being damaged in the welding process, and improving the safety performance of the battery.

As shown in connection with fig. 5, the weld mark 121 is spaced apart from the outer edge of the tab 12 in the first direction a, and the weld mark 121 may contact the outer edge of the tab 12 in the second direction B perpendicular to the first direction a.

In one embodiment, the tab 12 extends from the cell body 11 along the first direction a; wherein, on the second direction B of edge perpendicular to first direction A, weld the interval setting between seal 121 and the outward flange of utmost point ear 12 to guarantee that can not cause the damage to utmost point ear 12 among the welding process, and can guarantee utmost point ear 12 and apron subassembly's welding stability.

As shown in connection with fig. 6, the weld mark 121 may be in contact with the outer edge of the tab 12 in a first direction a, and the weld mark 121 may be spaced apart from the outer edge of the tab 12 in a second direction B perpendicular to the first direction a.

In one embodiment, the distance between the welding mark 121 and the outer edge of the tab 12 along the first direction a is 3mm to 10mm, so that on the basis of ensuring that the flow area is sufficient, the problems of damage to the tab 12 and the like caused by too large welding width can be avoided.

When the distance between the weld mark 121 and the outer edge of the tab 12 in the first direction a is less than 3mm, the weld width becomes too large, stress is concentrated at the weld position, and the top edge of the tab 12 is likely to be broken. When the distance between the welding mark 121 and the outer edge of the tab 12 is greater than 10mm, the problem that the welding width is too small and the flow area is not enough occurs.

In one embodiment, the distance between the weld mark 121 and the outer edge of the tab 12 in the first direction a may be 3mm, 3.1mm, 3.3mm, 3.5mm, 4mm, 4.5mm, 5mm, 6mm, 7mm, 8mm, 8.5mm, 9mm, 9.5mm, 9.8mm, 9.9mm, or 10mm, etc.

In one embodiment, the tab 12 extends from the cell body 11 along a first direction a, the tab 12 includes a negative tab, and the length of the weld mark 121 is smaller than that of the negative tab along a second direction B perpendicular to the first direction a; wherein, along on the second direction B, the distance between the outward flange of welding seal 121 and negative pole utmost point ear is 3mm ~ 15mm, on the one hand, avoids welding length undersize, and the area of overflowing is not enough, and on the other hand, if welding seal 121 length is great, the welding energy of continuous input causes utmost point ear 12 border position more fragile, when utmost point ear 12 buckles, negative pole utmost point ear turns over the book downwards easily promptly, if inside negative pole utmost point ear stretches into electric core main part 11, increases with anodal utmost point ear short circuit risk. If the tab 12 is folded upwards, the insulation failure of the negative tab and the battery shell occurs, so that the problem of electric corrosion occurs.

It should be noted that, the number of the tabs 12 of the battery cell 10 may be two, the two tabs are respectively a positive tab and a negative tab, and the negative tab needs to be insulated from the battery case, for example, the negative tab needs to be insulated from the cover plate, so as to avoid the occurrence of the galvanic corrosion problem. In the embodiment, the distance between the welding mark 121 and the outer edge of the negative electrode tab is 3mm to 15mm along the second direction B, so that the short circuit risk caused by the deformation of the negative electrode tab and the contact with the cover plate is avoided.

The battery includes a cell and an electrolyte, and a minimum unit capable of performing an electrochemical reaction such as charge/discharge. The battery cell refers to a unit formed by winding or laminating a stack including a first electrode, a separator, and a second electrode. When the first electrode is a positive electrode, the second electrode is a negative electrode. Wherein the polarities of the first electrode and the second electrode can be interchanged. For example, when the first electrode is a positive electrode, the second electrode is a negative electrode, and when the edge position of the negative electrode tab is relatively weak, the negative electrode tab is easily folded down, increasing the risk of short circuit with the positive electrode.

The battery can be the lamination formula battery, and it is convenient not only to organize, and can process and obtain the longer battery of length.

Specifically, the battery cell 10 is a laminated battery cell, and the battery cell 10 has a first pole piece, a second pole piece opposite to the first pole piece in electrical property, and a diaphragm disposed between the first pole piece and the second pole piece, so that a plurality of pairs of the first pole piece and the second pole piece are stacked to form the laminated battery cell. Example (b)

The battery can also be a winding battery, that is, a first pole piece, a second pole piece with an opposite electrical property to the first pole piece, and a diaphragm sheet arranged between the first pole piece and the second pole piece are wound to obtain a winding battery cell.

The tab 12 may include a plurality of single tabs, the tab 12 is formed after the plurality of single tabs are folded, and the welding mark 121 also realizes connection of the plurality of single tabs. The single tab may be a metal sheet, the metal sheet is a metal sheet, and the metal sheet may be a part of the current collector, or may have other options, which is not specifically limited herein.

In one embodiment, the battery cells 10 may be disposed within a battery housing, and one or more battery cells 10 may be disposed within the battery housing, as shown in fig. 1, where two battery cells 10 may be disposed within the battery housing.

In one embodiment, as shown in fig. 3, the cover plate assembly includes a cover plate 20 and a post assembly 30, the post assembly 30 is disposed on the cover plate 20, and the welding mark 121 is formed by welding the tab 12 and the post assembly 30 to connect the tab 12 and the post assembly 30, so as to ensure the connection stability of the tab 12 and the post assembly 30, thereby improving the welding quality of the tab 12 and the post assembly 30, and ensuring the safety performance of the battery.

The pole assembly 30 may be directly welded to the tab 12, that is, an interposer in the related art may be removed, material cost may be reduced, a process may be simplified, and the overall weight of the battery may be reduced, as shown in fig. 3, it may be considered that the pole assembly 30 may be directly welded to the tab 12.

In one embodiment, as shown in fig. 1 and fig. 2, the cover plate assembly includes a cover plate 20, a pole assembly 30 and an adaptor plate 40, the pole assembly 30 is disposed on the cover plate 20, the adaptor plate 40 is connected to the pole assembly 30, the welding seal 121 is formed by welding the pole tab 12 and the adaptor plate 40, so as to connect the pole tab 12 and the adaptor plate 40, the pole tab 12 is electrically connected to the pole assembly 30 through the adaptor plate 40, which not only facilitates the position arrangement of the pole assembly 30, but also facilitates the adaptor plate 40 to connect the pole tab 12 and the pole assembly 30.

The first section of the adapter sheet 40 is connected to the pole assembly 30, and the second section of the adapter sheet 40 is connected to the tab 12, and at this time, the first section and the second section may not coincide, so that the first section of the adapter sheet 40 and the pole assembly 30 may be welded or riveted, and the second section of the adapter sheet 40 and the tab 12 are welded, and the weld 121 is formed. The adaptor sheet 40 can be welded with the pole assembly 30 and the tab 12 at the same time, that is, the adaptor sheet 40 can form a welding mark 121 when being welded with the pole assembly 30 and the tab 12 at the same time, so as to improve the welding efficiency.

In one embodiment, the battery further includes a housing member 50, and the cover plate assembly is coupled to the housing member 50, thereby achieving reliable sealing of the battery cell 10. The number of the cover plate assemblies may be two, the two cover plate assemblies are respectively disposed at two opposite ends of the shell member 50, and the two pole post assemblies 30 may be respectively disposed on the two cover plates 20. In some embodiments, the cover assembly may be one, the cover assembly is disposed on the housing member 50, and the two pole assemblies 30 may be disposed on one cover plate 20 at the same time.

The battery cell 10 includes two tabs 12, which are a positive tab and a negative tab respectively. The positive and negative electrode tabs may be connected by a corresponding adapter sheet 40 and the pole assembly 30.

In one embodiment, the tab 12 extends from the cell body 11 along the first direction a; along a second direction B perpendicular to the first direction A, the length of the pole lug 12 is 10 mm-70 mm, the length of the adapter sheet 40 is 5 mm-130 mm, and on the basis that the pole lug 12 and the adapter sheet 40 are guaranteed to have reliable areas, welding marks 121 are conveniently formed subsequently, so that reliable overcurrent capacity is guaranteed, and the phenomenon that the weight of a battery is increased and the energy density is reduced due to the fact that the pole lug 12 and the adapter sheet 40 are too large in size can be avoided.

It should be noted that, in order to reduce the temperature rise, the welding area between the tab 12 and the adaptor piece 40 may be appropriately enlarged, but a certain residual area may still be left in the tab 12, so the size of the tab 12 and the size of the adaptor piece 40 may be enlarged, but the oversize may cause the weight increase of the battery, and the energy density is reduced, so the size of the tab and the adaptor piece needs to be controlled within a certain range, and in this embodiment, the length of the tab 12 is 10mm to 70mm, and the length of the adaptor piece 40 is 5mm to 130mm, which may improve the performance of the battery.

In one embodiment, the length of the tab 12 is 15mm to 60mm, and the length of the adaptor sheet 40 is 10mm to 120mm along the second direction B, so as to ensure that the tab 12 and the adaptor sheet 40 have reliable overcurrent capacity, and also ensure the capacity density of the battery.

In one embodiment, the length of the tab 12 may be 5mm, 8mm, 9mm, 10mm, 12mm, 15mm, 20mm, 25mm, 30mm, 40mm, 50mm, 55mm, 60mm, 65mm, 68mm, 69mm, or 70mm, and so on.

The patch 40 may have a length of 5mm, 8mm, 9mm, 10mm, 12mm, 15mm, 20mm, 25mm, 30mm, 40mm, 50mm, 55mm, 60mm, 65mm, 68mm, 69mm, 70mm, 80mm, 90mm, 95mm, 100mm, 105mm, 110mm, 115mm, 118mm, 119mm, 120mm, 122mm, 125mm, 129mm, 130mm, or the like.

In one embodiment, the adapter plate 40 is welded with the pole assembly 30, the welding area of the adapter plate 40 and the pole assembly 30 is c, the area of the pole assembly 30 facing the adapter plate 40 is d, and c/d is more than or equal to 10% and less than or equal to 80%, so that a reliable welding area can be ensured between the adapter plate 40 and the pole assembly 30, and when the welding area of the adapter plate 40 and the pole assembly 30 is too large, namely the welding input capacity is low, the safety performance of other structures is affected due to too much heat.

In one embodiment, c/d is 20% to 50% to ensure a reliable flow area between the interposer 40 and the pole assembly 30 and to avoid excessive heat generation during welding.

In one embodiment, the ratio of the area c of the interface plate 40 to the pole assembly 30 that is welded to the pole assembly 30 to the area d of the pole assembly 30 facing the interface plate 40 may be 10%, 15%, 20%, 21%, 25%, 30%, 35%, 40%, 43%, 44%, 45%, 48%, 49%, 50%, 55%, 56%, 60%, 65%, 70%, 73%, 74%, 75%, 78%, 79%, or 80%, among others.

It should be noted that the surface of the pole assembly 30 facing the adaptor sheet 40 can be regarded as the surface of the surface where the adaptor sheet 40 is connected with the pole assembly 30, for example, the bottom surface of the pole assembly 30 is welded with the adaptor sheet 40, in this case, a part of the bottom surface of the pole assembly 30 is welded with the adaptor sheet 40, the area formed by welding a part of the bottom surface of the pole assembly 30 with the adaptor sheet 40 is c, the area of the bottom surface of the pole assembly 30 is d, and c/d is greater than or equal to 10% and less than or equal to 80%.

In one embodiment, as shown in fig. 1 to 3, a battery may include at least two battery cells 10, and positive and negative electrode tabs of the at least two battery cells may be respectively connected to the pole assembly 30 through an adaptor sheet 40.

An embodiment of the utility model also provides a group battery, including foretell battery.

The utility model discloses a group battery of embodiment includes the battery, the battery includes electric core 10 and apron subassembly, electric core 10 includes electric core main part 11 and the utmost point ear 12 that extends out by electric core main part 11, through be formed with welding seal 121 on utmost point ear 12, and the area of welding seal 121 is an, the area that utmost point ear 12 has the surface of welding seal 121 is b,0.2% a/b is less than or equal to 20%, not only can guarantee the area of overflowing of utmost point ear 12, avoid the too big damage utmost point ear 12 of temperature rise, and can avoid welding seal 121 area too big, cause utmost point ear 12 fracture or damage other exterior structures, improve welding quality with this, thereby improve the safety in service performance of group battery.

In one embodiment, the battery pack is a battery module or a battery pack. The battery pack may include a plurality of batteries, and the plurality of batteries may be connected in series or in parallel through the bus bar.

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

It should be noted that a plurality of batteries can be arranged in the battery box after forming the battery module, and the plurality of batteries can be fixed through the end plate and the side plate. A plurality of batteries can directly set up in the battery box, need not to pack a plurality of batteries promptly, and at this moment, can get rid of end plate and curb plate.

In one embodiment, as shown in fig. 7, the battery pack further includes a bus bar 60, the bus bar 60 is welded to the pole assembly 30 of the battery, the area where the bus bar 60 is welded to the pole assembly 30 is e, the area where the pole assembly 30 faces the bus bar 60 is f, and 0.004 ≦ a/b)/(e/f ≦ 7, so that balance between overcurrent of the tab 12 and the interposer 40 and overcurrent of the bus bar 60 and the pole assembly 30 can be maintained, current of the cell body 11 is led out through the tab 12, the tab 12 is connected to the interposer 40, and further current is transmitted to the pole assembly 30, and the bus bar 60 is connected to the pole assembly 30, so as to enable the current to be further led out.

The welding area of the pole assembly 30 and the bus bar 60 represents the size of the current which can be received, if the current transmitted from the tab 12 is large, namely the ratio is large, and the welding area of the pole assembly 30 and the bus bar 60 is small, the current transmitted from the tab 12 cannot be well transmitted to the battery pack, if the ratio is small, the current transmitted from the tab 12 is small, and the area of the pole assembly 30 and the bus bar 60 is large, which means that the area of the pole assembly 30 and the bus bar 60 is large, and the weight of the battery can be increased.

It should be noted that if the ratio (a/b)/(e/f) is too small:

the excessive value (e/f) indicates that the excessive design value of the overcurrent capacity of the connection between the pole assembly 30 and the bus bar 60 causes the large sizes of the pole assembly 30 and the bus bar 60, which affects the mass energy density of the battery and the battery pack, and also causes the increase of the cost.

Or, if the value (a/b) is too small, the designed value of the overcurrent capacity of the tab 12 and the adapter plate 40 is small, so that the temperature rise of the connecting position of the tab 12 and the adapter plate 40 is high, even fusing occurs, the requirement of the overcurrent capacity of the battery pack is not met, and even a safety risk occurs.

And the ratio (a/b)/(e/f) is too large:

if the value (e/f) is too small, the designed value of the overcurrent capacity of the connection between the pole assembly 30 and the bus bar 60 is too small, which causes high temperature rise at the connection position between the pole assembly 30 and the bus bar 60 and even fusing, and thus the overcurrent capacity requirement of the battery pack is not met, and even a safety risk occurs.

Or, the (a/b) value is too large, which means that the designed overcurrent capacity of the tab 12 and the adapter plate 40 is too large, which causes the sizes of the pole assembly 30 and the bus bar 60 to be too large, affects the mass energy density of the battery and the battery pack, and also causes the cost to increase.

In the embodiment, 0.004 ≦ (a/b)/(e/f) ≦ 7, so that a balance can be maintained between the overcurrent of the tab 12 and the interposer 40 and the overcurrent of the bus bar 60 and the pole assembly 30, thereby ensuring the service performance of the battery pack.

In one embodiment, 0.07 ≦ (a/b)/(e/f) ≦ 2.5, thereby maintaining a balance between the overcurrent of the tab 12 and the interposer 40 and the overcurrent of the busbar 60 and the pole assembly 30, avoiding safety risks due to imbalance between the two.

In one embodiment, (a/b)/(e/f) may be 0.004, 0.005, 0.008, 0.07, 0.072, 0.08, 0.088, 0.09, 0.095, 0.1, 0.2, 0.5, 0.6, 1, 2, 2.11, 2.12, 2.13, 2.5, 3, 4, 4.5, 5, 5.5, 6, 6.5, 6.55, 6.66, 6.67, 6.8, 6.9, or 7, and so forth.

In one embodiment, e/f is greater than or equal to 3% and less than or equal to 50%, and the energy density of the battery pack can be ensured on the basis of ensuring the overcurrent capacity of the bus bar 60 and the pole assembly 30.

In one embodiment, e/f is greater than or equal to 5% and less than or equal to 25%, so that the overcurrent capacity of the busbar 60 and the pole assembly 30 can be ensured, the poor connection stability of the busbar 60 and the pole assembly 30 is avoided, and the energy density of the battery pack can be ensured.

In one embodiment, the ratio between the area e of the bus bar 60 welded to the pole assembly 30 and the area f of the pole assembly 30 facing the bus bar 60 may be 3%, 4%, 4.5%, 5%, 8%, 10%, 15%, 20%, 21%, 25%, 30%, 35%, 40%, 43%, 44%, 45%, 48%, 49%, or 50%, among others.

It should be noted that the surface of the pole assembly 30 facing the bus bar 60 may be considered as the surface where the bus bar 60 is connected to the pole assembly 30, for example, the top surface of the pole assembly 30 is welded to the bus bar 60, in this case, a part of the top surface of the pole assembly 30 is welded to the bus bar 60, the area formed by welding a part of the bottom surface of the pole assembly 30 to the bus bar 60 is e, and the area of the top surface of the pole assembly 30 is d.

In one embodiment, the distance between the welding area formed by the bus bar 60 and the pole assembly 30 and the outer edge of the pole assembly 30 is 1 mm-10 mm, so that the welding area formed by the bus bar 60 and the pole assembly 30 can be located in the middle of the pole assembly 30, the welding stability of the bus bar 60 and the pole assembly 30 is ensured, and the overcurrent capacity of the bus bar 60 and the pole assembly 30 can be ensured.

In one embodiment, the distance between the welding area formed by the bus bar 60 and the pole assembly 30 and the outer edge of the pole assembly 30 is 3 mm-8 mm, so that on the basis of improving the welding capacity of the bus bar 60 and the pole assembly 30, the overcurrent capacity of the bus bar 60 and the pole assembly 30 can be ensured, and the problem of over-concentration of heat in the use process is avoided. The lower end of the pole assembly 30 is provided with a battery insulator, which is easily damaged if the bus bar 60 is welded directly to the edge of the pole assembly 30, thereby causing a short circuit.

In one embodiment, the distance between the welding area formed by the bus bar 60 and the pole assembly 30 and the outer edge of the pole assembly 30 may be 1mm, 1.2mm, 1.5mm, 2mm, 3mm, 4mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 9.8mm, 9.9mm, or 10mm, etc.

In one embodiment, the bus bar 60 comprises a high voltage output end 61, the battery pack further comprises a high voltage copper bar 70, the high voltage copper bar 70 is connected with the high voltage output end 61, the area of the high voltage copper bar 70 contacting with the high voltage output end 61 is g, the area of the high voltage output end 61 facing the high voltage copper bar 70 is h,20% or more of g/h is 95% or less, so that reliable overcurrent capacity can be guaranteed between the high voltage copper bar 70 and the high voltage output end 61, too large welding area of the high voltage copper bar 70 and the high voltage output end 61 can be avoided, welding efficiency cannot be improved easily, and relative balance of the overcurrent capacity at each position can be guaranteed.

Through the limit of the welding area of the tab 21 and the pole assembly 30 or the adapter plate 40, the limit of the welding area of the bus bar 60 and the pole assembly 30, and the limit of the connection area of the high-voltage output end 61 and the high-voltage copper bar 70, the relative balance of the overcurrent capacity of each position in the battery pack can be ensured.

In one embodiment, the ratio of g/h is greater than or equal to 30% and less than or equal to 60%, so that reliable welding strength between the high-voltage copper bar 70 and the high-voltage output end 61 can be ensured, connection failure between the high-voltage copper bar 70 and the high-voltage output end 61 due to large heat in the charging and discharging process of the battery pack can be avoided, and the high-voltage copper bar 70 and the high-voltage output end 61 can be ensured to have proper sizes.

In one embodiment, the ratio of the contact area g of the high voltage copper bar 70 and the high voltage output end 61 to the area h of the high voltage output end 61 facing the high voltage copper bar 70 may be 20%, 21%, 25%, 30%, 35%, 40%, 43%, 44%, 45%, 48%, 49%, 50%, 55%, 60%, 65%, 70%, 73%, 74%, 75%, 80%, 85%, 90%, 91%, 93%, 94% or 95%.

It should be noted that the high-voltage output end 61 of the bus bar 60 may connect the total transmission formed by connecting the batteries of the battery pack in series or in parallel to the high-voltage copper bar 70, so that the high-voltage copper bar 70 can be used as a charging and discharging structure of the battery pack. The surface of the high voltage output end 61 facing the high voltage copper bar 70 can be considered as the surface of the high voltage output end 61 used for contacting with the high voltage copper bar 70, for example, the surface of the high voltage output end 61 is a plane, a part of the plane contacts with the high voltage copper bar 70, the area of the plane contacting with the high voltage copper bar 70 is g, and the area of the plane of the high voltage output end 61 is h.

As shown in fig. 7, the plurality of batteries may be connected by a plurality of busbars 60, the plurality of batteries may form a plurality of rows of battery modules, and the battery modules may be connected by a connection structure, and the battery pack may include two busbars 60 having high voltage output terminals 61 and may be respectively connected to two high voltage copper bars 70, so as to be used for the positive connection terminal and the negative connection terminal of the battery pack.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the invention 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. It is intended that the specification and example embodiments be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

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

Claims

1. A battery, comprising:

the battery cell (10), wherein the battery cell (10) comprises a cell main body (11) and tabs (12), and the tabs (12) extend out of the cell main body (11);

a cover plate assembly welded with the tab (12) to form a weld impression (121);

the area of the welding print (121) is a, the area of the surface of the tab (12) with the welding print (121) is b, and a/b is more than or equal to 0.2% and less than or equal to 20%.

2. The battery of claim 1, wherein 1.8% ≦ a/b ≦ 10.6%.

3. The battery according to claim 2, wherein the tab (12) extends from the cell body (11) in a first direction;

wherein the welding imprints (121) are spaced from the outer edges of the tabs (12) along the first direction, and/or the welding imprints (121) are spaced from the outer edges of the tabs (12) along a second direction perpendicular to the first direction.

4. The battery according to claim 3, wherein a distance between the weld mark (121) and an outer edge of the tab (12) in the first direction is 3mm to 10mm.

5. The battery according to claim 1, wherein the tab (12) extends from the cell body (11) in a first direction, the tab (12) comprises a negative tab, and the length of the weld mark (121) is less than the length of the negative tab in a second direction perpendicular to the first direction;

and in the second direction, the distance between the welding mark (121) and the outer edge of the negative pole lug is 3-15 mm.

6. The battery according to claim 1, characterized in that the cover plate assembly comprises a cover plate (20) and a pole assembly (30), the pole assembly (30) is arranged on the cover plate (20), and the welding mark (121) is formed by welding the pole tab (12) and the pole assembly (30) to connect the pole tab (12) and the pole assembly (30).

7. The battery according to claim 1, wherein the cover plate assembly comprises a cover plate (20), a pole assembly (30) and an adapter plate (40), the pole assembly (30) is disposed on the cover plate (20), the adapter plate (40) is connected with the pole assembly (30), and the welding mark (121) is formed by welding the tab (12) and the adapter plate (40) to connect the tab (12) and the adapter plate (40).

8. The battery according to claim 7, wherein the tab (12) extends from the cell body (11) in a first direction;

and the length of the pole lug (12) is 10-70 mm along a second direction perpendicular to the first direction, and the length of the adapter sheet (40) is 5-130 mm.

9. The battery according to claim 8, wherein the tab (12) has a length of 15mm to 60mm and the interposer (40) has a length of 10mm to 120mm in the second direction.

10. The battery according to any one of claims 7 to 9, characterized in that the interposer (40) is welded with the pole assembly (30), the area of the interposer (40) welded with the pole assembly (30) is c, the area of the pole assembly (30) facing the interposer (40) is d, and c/d is more than or equal to 10% and less than or equal to 80%.

11. The battery of claim 10, wherein 20% c/d is 50%.

12. A battery comprising the cell of any one of claims 1 to 11.

13. The battery pack of claim 12, further comprising a bus bar (60), the bus bar (60) being welded to the cell's pole assembly (30), the bus bar (60) being welded to the pole assembly (30) over an area of e, the pole assembly (30) having an area toward the bus bar (60) of f,0.004 ≦ (a/b)/(e/f) ≦ 7.

14. The battery of claim 13, wherein 0.07 ≦ (a/b)/(e/f) 2.5.

15. The battery according to claim 13 or 14, wherein 3% e/f is 50%.

16. The battery of claim 15, wherein 5% ≦ e/f ≦ 25%.

17. The battery according to claim 13, characterized in that the distance between the welded area formed by the busbar (60) and the pole assembly (30) and the outer edge of the pole assembly (30) is between 1mm and 10mm.

18. The battery according to claim 17, characterized in that the distance between the welded area of the busbar (60) with the pole assembly (30) and the outer edge of the pole assembly (30) is between 3 and 8mm.

19. The battery pack according to claim 13, wherein the busbar (60) comprises a high voltage output (61), the battery pack further comprises a high voltage copper bar (70), the high voltage copper bar (70) is connected with the high voltage output (61), the area of the high voltage copper bar (70) in contact with the high voltage output (61) is g, the area of the high voltage output (61) facing the high voltage copper bar (70) is h, and 20% or more and g/h or less are 95%.

20. The battery of claim 19, wherein 30% g/h 60%.