CN220544083U

CN220544083U - Battery and battery pack

Info

Publication number: CN220544083U
Application number: CN202322064321.5U
Authority: CN
Inventors: 张勇杰; 许博伟; 张璐璐; 王娟
Original assignee: China Innovation Aviation Technology Group Co ltd
Current assignee: China Innovation Aviation Technology Group Co ltd
Priority date: 2023-08-02
Filing date: 2023-08-02
Publication date: 2024-02-27
Anticipated expiration: 2033-08-02

Abstract

The utility model relates to the technical field of batteries, and provides a battery and a battery pack. The battery includes battery case and the electric core of setting in the battery case, and the electric core has two relative first surfaces and encircles the second surface that two first surfaces set up, and the area of first surface is greater than the area of second surface, and the battery case includes: a cover plate; the shell piece is connected with the cover plate and comprises a side wall and a bottom wall which are connected; the wall thickness of the bottom wall is 0.01mm-1.5mm, namely the wall thickness of the bottom wall is larger than that of the first side wall, so that the bottom wall has enough strength to form a support for the battery cell, the relatively thinner first side wall can dissipate heat of the large surface of the battery cell, the heat in the battery is reduced, the occurrence probability of thermal runaway is reduced, and the safe service performance of the battery is improved.

Description

Battery and battery pack

Technical Field

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

Background

In the related art, during the use process of the battery, a great amount of heat generation occurs in the battery due to the charge and discharge cycle, and if the heat is not timely discharged, the safety performance of the battery may be affected, however, due to the structural limitation of the battery housing, the situation that the heat dissipation of each surface of the battery housing is extremely uneven may exist.

Disclosure of Invention

The utility model provides a battery and a battery pack, which are used for improving the service performance of the battery.

According to a first aspect of the present utility model, there is provided a battery including a battery case and a battery cell provided in the battery case, the battery cell having two opposite first surfaces and a second surface provided around the two first surfaces, the first surface having an area larger than that of the second surface, the battery case comprising:

a cover plate;

the shell piece is connected with the cover plate and comprises a side wall and a bottom wall which are connected;

wherein the side wall comprises a first side wall opposite to the first surface, and the difference between the wall thickness of the bottom wall and the wall thickness of the first side wall is 0.01mm-1.5mm.

The battery provided by the embodiment of the utility model comprises the battery shell and the battery core, wherein the battery core is arranged in the battery shell, so that the battery shell forms the protection of the battery core, and the battery core can radiate heat through the battery shell. The battery shell comprises a cover plate and a shell piece, the first side wall of the side wall is opposite to the first surface of the battery cell, and the fact that the first surface of the battery cell generates more heat is considered, so that rapid heat dissipation is more needed to be realized through the first side wall. The difference between the wall thickness of the bottom wall and the wall thickness of the first side wall is 0.01mm-1.5mm, namely, the wall thickness of the bottom wall is larger than the wall thickness of the first side wall, so that the bottom wall has enough strength to form a support for the battery cell, the first surface heat of the battery cell can be dissipated through the relatively thinner first side wall, the internal heat of the battery is reduced, the occurrence probability of thermal runaway is reduced, and the safe service performance of the battery is improved. Meanwhile, the difference between the wall thickness of the bottom wall and the wall thickness of the first side wall is 0.01-1.5 mm, the situation that the wall thickness of the bottom wall and the wall thickness of the first side wall are too large in difference and the heat dissipation of the bottom wall and the side wall is seriously uneven is avoided, the serious uneven temperature of each surface of the battery is caused, meanwhile, the situation that the weight of the battery is too large and the energy density of the battery is low due to the fact that the bottom wall is too thick can be avoided.

According to a second aspect of the present utility model, there is provided a battery pack including the above-described battery, the battery being plural.

The battery pack of the embodiment of the utility model comprises a plurality of batteries, wherein the batteries comprise a battery shell and a battery core, and the battery core is arranged in the battery shell, so that the battery shell forms the protection of the battery core, and the battery core can radiate heat through the battery shell. The battery shell comprises a cover plate and a shell piece, the first side wall of the side wall is opposite to the first surface of the battery cell, and the fact that the first surface of the battery cell generates more heat is considered, so that rapid heat dissipation is more needed to be realized through the first side wall. The difference between the wall thickness of the bottom wall and the wall thickness of the first side wall is 0.01mm-1.5mm, namely, the wall thickness of the bottom wall is larger than the wall thickness of the first side wall, so that the bottom wall has enough strength to form a support for the battery cell, the first surface heat of the battery cell can be dissipated through the relatively thinner first side wall, the internal heat of the battery is reduced, the occurrence probability of thermal runaway is reduced, and the safe service performance of the battery is improved. Meanwhile, the difference between the wall thickness of the bottom wall and the wall thickness of the first side wall is 0.01-1.5 mm, the situation that the wall thickness of the bottom wall and the wall thickness of the first side wall are too large in difference and the heat dissipation of the bottom wall and the side wall is seriously uneven is avoided, the serious uneven temperature of each surface of the battery is caused, meanwhile, the situation that the weight of the battery is too large and the energy density of the battery is low due to the fact that the bottom wall is too thick can be avoided.

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 an exploded structural view showing one view angle of a battery according to an exemplary embodiment;

fig. 3 is an exploded view of another view of a battery according to an exemplary embodiment;

fig. 4 is an exploded structural view of a battery according to another exemplary embodiment;

fig. 5 is a partially cross-sectional structure schematic view of a battery case of a battery according to an exemplary embodiment;

fig. 6 is a schematic structural view of a battery cell of a battery according to an exemplary embodiment;

FIG. 7 is a partially expanded schematic illustration of a battery cell of a battery according to an exemplary embodiment;

Fig. 8 is a schematic view showing the structure of a positive electrode tab or a negative electrode tab of a battery according to an exemplary embodiment;

fig. 9 is a schematic view of a structure of a battery according to another exemplary embodiment;

fig. 10 is a schematic view illustrating a structure of a battery pack according to an exemplary embodiment;

fig. 11 is a schematic structural view of a battery pack according to another exemplary embodiment.

The reference numerals are explained as follows:

10. a battery case; 11. a cover plate; 12. a housing member; 121. a sidewall; 1211. a first sidewall; 1212. a second sidewall; 1213. a top wall; 122. a bottom wall; 20. a battery cell; 211. a first surface; 212. a second surface; 22. a cell body; 23. a tab; 24. a positive electrode sheet; 25. a negative electrode plate; 26. a diaphragm; 27. a recess; 30. a pole assembly; 40. a pressure relief structure; 50. a protective patch; 51. scoring; 60. a heat exchange assembly; 70. and a bottom support.

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.

An embodiment of the present utility model provides a battery, referring to fig. 1 to 9, the battery includes a battery case 10 and a battery cell 20 disposed in the battery case 10, the battery cell 20 having two opposite first surfaces 211 and a second surface 212 disposed around the two first surfaces 211, the first surface 211 having an area larger than that of the second surface 212, the battery case 10 including: a cover plate 11; a housing member 12, the housing member 12 being connected to the cover plate 11, the housing member 12 including a side wall 121 and a bottom wall 122, the side wall 121 being connected to the bottom wall 122; wherein the side wall 121 comprises a first side wall 1211 opposite the first surface 211, the difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 being 0.01mm-1.5mm.

The battery of one embodiment of the present utility model includes a battery case 10 and a battery cell 20, the battery cell 20 being disposed within the battery case 10, whereby the battery case 10 forms protection for the battery cell 20, and the battery cell 20 may form heat dissipation through the battery case 10. The battery case 10 includes the cover plate 11 and the case member 12, and the first side wall 1211 of the side wall 121 is disposed opposite to the first surface 211 of the battery cell 20, so that rapid heat dissipation through the first side wall 1211 is more required in consideration of the fact that the first surface 211 of the battery cell 20 generates more heat. The difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 is 0.01mm-1.5mm, i.e. the wall thickness of the bottom wall 122 is greater than the wall thickness of the first side wall 1211, so that the bottom wall 122 has enough strength to form a support for the battery cell 20, and the relatively thin first side wall 1211 can dissipate heat from the first surface 211 of the battery cell 20, so as to reduce the heat in the battery, reduce the occurrence probability of thermal runaway, and improve the safe service performance of the battery. Meanwhile, the difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 is 0.01mm-1.5mm, so that the situation that the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 are too large, the heat dissipation of the bottom wall 122 and the side wall 121 is seriously uneven, the temperature of each side of the battery is seriously uneven is avoided, meanwhile, the situation that the weight of the battery is too large and the energy density of the battery is low due to the fact that the bottom wall 122 is too thick can be avoided.

It should be noted that, as shown in fig. 1 and 2, the battery case 10 includes a cover plate 11 and a case member 12, and the case member 12 is connected to the cover plate 11, so as to form a housing for the battery cell 20, and realize protection for the battery cell 20. The housing part 12 and the cover plate 11 can be welded together.

As shown in fig. 6, the cell 20 has two opposite first surfaces 211 and four second surfaces 212 disposed around the two first surfaces 211, and the area of the first surfaces 211 is larger than that of the second surfaces 212, i.e., the first surfaces 211 may be large surfaces of the cell 20. The surface with the largest area of the battery cell 20 can be regarded as the first surface 211 of the battery cell 20, and the first surface 211 of the battery cell 20 can generate relatively more heat in the charge and discharge process of the battery cell 20, so that the heat needs to be rapidly dissipated, and the problems of thermal runaway and the like are avoided. The number of the second surfaces 212 may be four, and the four second surfaces 212 may be two side surfaces, a top surface, and a bottom surface of the battery cell 20, respectively.

While the side wall 121 includes the first side wall 1211 opposite to the first surface 211, at this time, the first side wall 1211 takes charge of heat dissipation from the first surface 211 of the battery cell 20, and considering that the difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 is 0.01mm-1.5mm, that is, the wall thickness of the first side wall 1211 may be relatively small, so that not only the heat can be quickly dissipated, but also the weight of the battery can be appropriately reduced, the energy density of the battery can be improved to a certain extent, and the space occupation rate of a single battery can be reduced when the battery is grouped.

The wall thickness of the bottom wall 122 is larger than that of the first side wall 1211, the bottom wall 122 plays a role in stably supporting the battery cells 20, the wall thickness of the first side wall 1211 is thinner, the first side wall 1211 corresponds to the first surface 211 of the battery cells 20, when the batteries are stacked into groups, the first side walls 1211 of the batteries are oppositely arranged, the first side wall 1211 is thinner, the occupied space of the battery shell 10 is reduced, after the batteries are placed in the battery box, the number of the batteries which can be accommodated is increased under the same battery box space, and the energy density of the whole battery pack is improved. In addition, the heat generated by the charge and discharge of the battery needs to be dissipated through the battery case 10, the first surface 211 of the battery cell 20 has the largest heat dissipation area, and the wall thickness of the first sidewall 1211 opposite to the first surface 211 of the battery cell 20 is relatively thin, so that the heat of the first surface 211 of the battery cell 20 can be dissipated, the heat inside the battery is reduced, and the occurrence probability of thermal runaway is reduced.

When the difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 is 0.01mm to 1.5mm and the difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 is too large, the wall thickness of the bottom wall 122 is too large or the wall thickness of the first side wall 1211 is too small, so that heat transfer between the bottom wall 122 and the side wall 121 is not uniform, which is not beneficial to improving the safety performance of the battery. When the difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 is too small, the weight of the battery case 10 is relatively large, and the occupied space is large, which is disadvantageous in increasing the energy density of the battery.

In one embodiment, the bottom wall 122 is integrally formed with the first side wall 1211, so that the forming efficiency of the bottom wall 122 and the first side wall 1211 can be improved.

In one embodiment, the housing member 12 may be of an integrally formed type construction, which may not only improve the molding efficiency of the housing member 12, but may also improve the structural strength of the housing member 12.

In one embodiment, as shown in fig. 1 to 3, the side wall 121 and the bottom wall 122 are integrally formed, the cover 11 is connected to the side wall 121, and the cover 11 is disposed opposite to the bottom wall 122, so that not only the structural strength of the housing member 12 can be ensured, but also the forming efficiency of the housing member 12 can be improved.

As shown in fig. 1 and 2, the housing member 12 includes a side wall 121 and a bottom wall 122, the housing member 12 may form a cavity for accommodating the battery cell 20, and the cover 11 is connected to the side wall 121, and the cover 11 is disposed opposite to the bottom wall 122, that is, the cover 11 and the housing member 12 may form a storage for the battery cell 20, so as to implement protection for the battery cell 20.

The side wall 121 and the bottom wall 122 are integrally formed, for example, the side wall 121 and the bottom wall 122 of the housing member 12 can be integrally formed by a stamping process, so that the structural strength of the side wall 121 and the bottom wall 122 can be ensured, the occurrence of a connecting gap is avoided, and the manufacturing efficiency of the battery can be effectively improved.

The cover plate 11 and the side wall 121 may be welded, for example, the cover plate 11 and the side wall 121 may be welded by laser welding, ultrasonic welding, resistance welding, or the like, which is not limited herein.

In one embodiment, the difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 is 0.1mm-1mm, and on the basis of satisfying the structural strength, the heat dissipation requirement can be satisfied, so that the bottom wall 122 and the first side wall 1211 have relatively uniform heat dissipation capability.

In one embodiment, the difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 is 0.4mm-0.7mm, which not only ensures that the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 can have a certain difference, controls the weight and the approaching occupancy rate of the battery case 10, but also avoids the problem of too uneven heat of the battery case 10.

It should be noted that, as shown in fig. 5, the wall thickness of the bottom wall 122 may be denoted as x, the wall thickness of the first side wall 1211 may be denoted as y, and the difference between the wall thickness x of the bottom wall 122 and the wall thickness y of the first side wall 1211 may be 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.05mm, 1.1mm, 1.15mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, 1.45mm, or the like.

In one embodiment, the cover plate 11 is disposed opposite to the bottom wall 122, the area of the outer surface of the bottom wall 122 is a, the area of the outer surface of the side wall 121 is b, a/b is 0.05-0.25, and the heat dissipation capacity of the casing member 12 can be effectively controlled on the basis of ensuring the structural strength of the casing member 12, and the heat dissipation at each position of the casing member 12 is ensured to be uniform, so that the safe use performance of the battery is effectively improved.

Considering that the wall thickness of the bottom wall 122 does not coincide with the wall thickness of the first side wall 1211 of the side wall 121, uneven heat dissipation from the respective faces of the battery may occur. The ratio of the area a of the outer surface of the bottom wall 122 to the area b of the outer surface of the side wall 121 is too small, the area a of the outer surface of the bottom wall 122 is too small, or the area b of the outer surface of the side wall 121 is too large, the wall thickness of the bottom wall 122 is larger than that of the first side wall 1211, the heat dissipation effect of the bottom wall 122 is poor, the heat dissipation effect of the side wall 121 is good, uneven heat dissipation between the bottom wall 122 and the side wall 121 is finally caused, and the local temperature of the battery is high. The ratio of the area a of the outer surface of the bottom wall 122 to the area b of the outer surface of the side wall 121 is too large, the area a of the outer surface of the bottom wall 122 is too large, or the area b of the outer surface of the side wall 121 is too small, the heat dissipation effect of the bottom wall 122 is relatively good, but the heat dissipation effect of the side wall 121 may be poor, uneven heat dissipation between the bottom wall 122 and the side wall 121 is finally caused, and the local temperature of the battery is high. In addition, although the heat dissipation effect of the bottom wall 122 is improved, the area b of the outer surface of the side wall 121 is too small, and the heat generated by the battery cell 20 corresponding to the side wall position of the side wall 121 is large, which may cause uneven heat dissipation of the bottom wall 122 and the bottom wall 122.

The ratio of the area a of the outer surface of the bottom wall 122 to the area b of the outer surface of the side wall 121 is 0.05-0.25, which can effectively control the uniformity of heat dissipation of the bottom wall 122 and the side wall 121 and effectively improve the safety performance of the battery.

The ratio of the area a of the outer surface of the bottom wall 122 to the area b of the outer surface of the side wall 121 may be 0.05, 0.06, 0.08, 0.1, 0.12, 0.15, 0.18, 0.2, 0.22, 0.24, or 0.25, etc.

The battery includes a cell and an electrolyte, and is a minimum unit capable of performing an electrochemical reaction such as charge/discharge.

The battery may be a quadrangular type battery, which mainly refers to a prismatic shape, but does not strictly define whether each side of the prism is necessarily a strictly defined straight line, and the corners between sides are not necessarily right angles, and may be arc transitions.

The battery can be a laminated battery, so that the battery is not only convenient to group, but also long in length. Specifically, the battery cell is a laminated battery cell, and the battery cell is provided with a positive pole piece, a negative pole piece opposite to the positive pole piece in electrical property and a diaphragm arranged between the positive pole piece and the negative pole piece, so that a plurality of pairs of positive pole pieces and negative pole pieces are stacked to form the laminated battery cell.

Or, the battery may be a winding type battery, that is, the battery core is a winding type battery core, and the positive electrode plate, the negative electrode plate opposite to the positive electrode plate and the diaphragm arranged between the positive electrode plate and the negative electrode plate are wound to obtain the winding type battery core.

In one embodiment, the thickness of the battery is 15mm-80mm in the direction perpendicular to the first surface 211, and the energy density of the battery can be controlled on the basis of ensuring the capacity of the battery, and the problem that the heat of the battery cannot be dissipated in time is avoided, thereby leading to a safety problem.

One or more battery cells 20 may be disposed in the battery case 10, and the greater the thickness of the battery, the greater the total thickness of the battery cells 20 in the battery case 10, the greater the thickness of the battery, the slower the speed of heat transfer from the inside of the battery cells 20 to the battery case 10, and the poor heat dissipation effect of the battery side walls, resulting in easy accumulation of heat inside the battery. And considering that the wall thickness of the bottom wall 122 is relatively large, the heat dissipation effect of the battery cell 20 from the bottom is relatively poor, and the total thickness of the battery cell 20 is relatively large, so that the heat reaching the bottom wall 122 along the height direction of the battery cell 20 is relatively large, and the wall thickness of the bottom wall 122 is relatively large, which causes heat concentration. The thickness of the battery cannot be too small, which means that the thickness of the internal cell 20 is relatively small, resulting in a lower energy density of the battery and a faster side wall heat dissipation, which also results in non-uniform heat due to the slower heat dissipation from the bottom wall 122.

In one embodiment, the thickness of the battery is 40mm-55mm, so that the battery can be guaranteed to realize rapid heat dissipation, the problem of thermal runaway is avoided, the capacity of the battery can be effectively controlled, and the energy density of the battery can be improved.

The thickness of the battery may be 15mm, 18mm, 20mm, 22mm, 25mm, 28mm, 30mm, 32mm, 35mm, 38mm, 40mm, 42mm, 45mm, 48mm, 50mm, 52mm, 55mm, 58mm, 60mm, 62mm, 65mm, 68mm, 70mm, 72mm, 75mm, 78mm, 80mm or the like.

In one embodiment, the wall thickness of the bottom wall 122 is 0.1mm-1.5mm, which not only can effectively control the structural strength of the bottom wall 122 and ensure the energy density of the battery, but also can ensure the bottom wall 122 to have reliable heat dissipation capability, thereby improving the safety performance of the battery.

In one embodiment, the wall thickness of the bottom wall 122 is 0.4mm-1.5mm, and the weight of the bottom wall 122 can be further controlled on the basis of ensuring the structural strength of the bottom wall 122, so as to effectively control the energy density of the battery.

In one embodiment, the wall thickness of the bottom wall 122 is 0.8mm-1.2mm, which not only ensures that the bottom wall 122 can provide enough support for the battery cell 20, avoiding structural damage, but also can effectively control the weight of the bottom wall 122 and improve the energy density of the battery to the greatest extent.

The wall thickness of the bottom wall 122 may be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.45mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.85mm, 0.9mm, 1mm, 1.1mm, 1.15mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, 1.45mm, 1.5mm, or the like.

In one embodiment, the wall thickness of the first side wall 1211 is 0.03mm-1mm, so that the wall thickness of the first side wall 1211 is smaller than the wall thickness of the bottom wall 122, reliable heat dissipation of the first side wall 1211 to the battery cell 20 is achieved, and the heat dissipation balancing capability of the first side wall 1211 and the bottom wall 122 can also be controlled.

In one embodiment, the wall thickness of the first side wall 1211 is 0.3mm-0.8mm, so that the heat dissipation capability of the first side wall 1211 can be effectively controlled, the first side wall 1211 can be ensured to be capable of forming efficient heat dissipation to the battery core 20, the problem of thermal runaway of the battery is avoided, and the safe use performance of the battery is effectively improved.

In one embodiment, the wall thickness of the first side wall 1211 is 0.35mm-0.5mm, and the structural strength of the first side wall 1211 can be controlled on the basis of ensuring the heat dissipation capability of the first side wall 1211, so that the problems of partial structural damage of the battery case 10 and uneven heat dissipation caused by the wall thickness of the first side wall 1211 can be avoided.

The wall thickness of the first side wall 1211 may be 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.1mm, 0.12mm, 0.15mm, 0.18mm, 0.2mm, 0.22mm, 0.25mm, 0.28mm, 0.3mm, 0.32mm, 0.34mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, or 1mm, or the like.

In one embodiment, the battery cell 20 has two opposite first surfaces 211, the side wall 121 includes two opposite first side walls 1211, the side wall 121 further includes two opposite second side walls 1212, and two ends of the second side walls 1212 are respectively connected to the two first side walls 1211, so that the side wall 121 substantially encloses a rectangular cavity, and efficient heat dissipation of the battery cell 20 can be achieved through the side wall 121, thereby improving the safe service performance of the battery.

In one embodiment, the wall thickness of the second side wall 1212 is greater than the wall thickness of the first side wall 1211, so that the structural strength of the second side wall 1212 can be ensured to be relatively high, structural damage caused by collision can be avoided, and the first side wall 1211 corresponding to the first surface 211 of the cell 20 can have better heat dissipation capability, and a certain collision space can be provided for the expansion of the cell 20.

The first side wall 1211 may be a wall opposite to adjacent cells in the battery pack, the second side wall 1212 is a wall exposed or adjacent to other cell components, and the second side wall 1212 is more susceptible to external impact or collision with the outside, so that the wall thickness of the second side wall 1212 is greater than that of the first side wall 1211, and the structural strength of the second side wall 1212 may be increased. The first side wall 1211 corresponds to the first surface 211 of the battery cell 20, the first surface 211 of the battery cell 20 expands seriously, the wall thickness of the first side wall 1211 is thinner, and a certain space is reserved for the expansion of the battery cell 20.

In one embodiment, the cover 11 is disposed opposite to the bottom wall 122, and the ratio of the outer surface area of the first side wall 1211 to the outer surface area of the second side wall 1212 is 2-40, which not only can satisfy the space requirement when the batteries are grouped, but also can provide space for the expansion of the battery cells 20, and can ensure that the batteries can have relatively uniform heat dissipation capability.

When the ratio of the outer surface area of the first side wall 1211 to the outer surface area of the second side wall 1212 is too large, the outer surface area of the first side wall 1211 is too large, or the outer surface area of the second side wall 1212 is too small, the outer surface area of the first side wall 1211 is too large, the first side walls 1211 of adjacent cells are arranged opposite to each other, the second side wall 1212 is a part which is relatively exposed or adjacent to other cell components, during charging and discharging, the cells expand, and since a plurality of cells can be stacked together, the expansion of the first side wall 1211 does not greatly affect the whole cell group, but the expansion of the cells can drive the side wall 121 to expand or even deform, and the larger the outer surface area of the second side wall 1212 drives the side wall 121 to deform more and more risk. The smaller the outer surface area of the second sidewall 1212, the less the second sidewall 1212 is deformed by extrusion expansion, but the smaller the thickness of the battery cell 20 is, the larger the number of cells to be stacked is, and the cell stacking process is increased, and in addition, the larger the number of cells to be stacked is, and the larger the amount of glue between cells is due to the smaller outer surface area of the second sidewall 1212. In addition, when the ratio of the outer surface area of the first side wall 1211 to the outer surface area of the second side wall 1212 is too small, the outer surface area of the first side wall 1211 is too small, or the outer surface area of the second side wall 1212 is too large, the risk of the second side wall 1212 being pulled to deform when being expanded increases, and the heat dissipation capacity of the first side wall 1211 is also relatively small, which is disadvantageous for improving the heat dissipation capacity of the battery.

The ratio of the outer surface area of the first side wall 1211 to the outer surface area of the second side wall 1212 may be 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, or the like.

In one embodiment, the wall thickness of the second side wall 1212 is 0.05mm-1.2mm, which not only effectively controls the structural strength of the second side wall 1212, but also prevents the wall thickness of the second side wall 1212 from being too large to affect the overall energy density of the battery.

The wall thickness of the second sidewall 1212 may be 0.05mm, 0.08mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.85mm, 0.9mm, 1mm, 1.05mm, 1.1mm, 1.15mm, 1.2mm, or the like.

In one embodiment, as shown in fig. 1 and 4, the battery further includes a pole assembly 30, where the pole assembly 30 is disposed on the cover plate 11, and the pole assembly 30 is electrically connected to the battery core 20, and the cover plate 11 can provide sufficient support for the pole assembly 30, and can facilitate the disposition of the pole assembly 30, which is beneficial to improving the manufacturing efficiency of the battery.

The number of the electrode post assemblies 30 may be two, one is an anode electrode post assembly, the other is a cathode electrode post assembly, the battery core 20 may include a battery core main body 22 and two electrode tabs 23, the number of the electrode tabs 23 may be two, one of the two electrode tabs 23 is an anode electrode tab, the other is a cathode electrode tab, the anode electrode post assembly is electrically connected with the anode electrode tab, and the cathode electrode tab is electrically connected with the cathode electrode post assembly.

In one embodiment, the cover plate 11 is opposite to the bottom wall 122, and the difference between the thickness of the cover plate 11 and the wall thickness of the bottom wall 122 is 0.1mm-1.9mm, so that not only can the heat dissipation balance between the cover plate 11 and the bottom wall 122 be ensured, but also the problem that the heat of the cover plate 11 is too concentrated can be avoided.

When the heat is transferred inside the battery, except the heat is transferred outwards through the bottom wall 122, the heat is also transferred outwards through the cover plate 11, the difference between the thickness of the cover plate 11 and the wall thickness of the bottom wall 122 is too large, the heat of the cover plate 11 and the heat of the bottom wall 122 are easy to be uneven, the battery cell 20 and the pole assembly 30 need to be electrically connected, the heat generation amount at the electric connection position is large, namely, the heat generation amount at the position corresponding to the cover plate 11 is large, and the heat cannot be fully dissipated due to the fact that the cover plate 11 is too thick.

In one embodiment, the difference between the thickness of the cover plate 11 and the wall thickness of the bottom wall 122 is 0.3mm-1.0mm, so as to effectively ensure the overall heat dissipation capability of the battery and improve the safe use performance of the battery.

The difference between the thickness of the cover plate 11 and the wall thickness of the bottom wall 122 may be 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.1mm, 1.15mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, 1.5mm, 1.6mm, 1.65mm, 1.7mm, 1.75mm, 1.8mm, 1.85mm, or 1.9mm, etc.

In one embodiment, the cover plate 11 is disposed opposite to the bottom wall 122, and the difference between the thickness of the cover plate 11 and the wall thickness of the first side wall 1211 is 0.4mm-2mm, so that not only can the normal connection of the cover plate 11 and the side wall 121 be ensured, but also the heat dissipation capacity of the battery can be controlled.

The cover 11 may be welded to the side wall 121 to achieve battery sealing, where the difference between the thickness of the cover 11 and the wall thickness of the first side wall 1211 is too large, for example, the thickness of the cover 11 is too large and the wall thickness of the first side wall 1211 is too small, so that the welding power required to be applied to weld the cover 11 to the side wall 121 is large, which easily causes deformation of the first side wall 1211.

In one embodiment, the difference between the thickness of the cover plate 11 and the wall thickness of the first side wall 1211 is 0.7mm to 1.3mm, so that the connection efficiency of the cover plate 11 and the side wall 121 can be effectively controlled.

The difference between the thickness of the cover plate 11 and the wall thickness of the first side wall 1211 may be 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.1mm, 1.15mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, or 2mm, or the like.

In one embodiment, as shown in fig. 1 and 4, the battery further includes a post assembly 30, where the post assembly 30 is disposed on the cover plate 11, the battery cell 20 has two opposite first surfaces 211, the side wall 121 includes two opposite first side walls 1211, the side wall 121 further includes two opposite second side walls 1212, and two ends of the second side walls 1212 are respectively connected to the two first side walls 1211;

wherein, the difference between the thickness of the cover plate 11 and the wall thickness of the second side wall 1212 is 0.3mm-1.95mm, so that on the basis of ensuring the heat dissipation capability of the second side wall 1212, the too large difference between the thickness of the cover plate 11 and the wall thickness of the second side wall 1212 can be avoided, which is unfavorable for the connection of the cover plate 11 and the second side wall 1212.

The difference between the thickness of the cover plate 11 and the wall thickness of the second side wall 1212 may be 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.1mm, 1.15mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.85mm, 1.9mm, or 1.95mm, etc.

In one embodiment, the battery further includes a post assembly 30, the post assembly 30 being disposed on the housing member 12, for example, the post assembly 30 may be disposed on the bottom wall 122.

The material of the battery case 10 may be aluminum, or the material of the battery case 10 may be steel, or the material of the battery case 10 may be copper, etc., which is not limited herein.

In one embodiment, as shown in fig. 9, the side wall 121 includes two opposite first side walls 1211, the housing member 12 further includes a top wall 1213 disposed opposite to the bottom wall 122, and two ends of the top wall 1213 are respectively connected to the two first side walls 1211, so that the housing member 12 may be formed into a rectangular barrel structure, thereby facilitating installation of the battery cells 20 and grouping of subsequent battery cells.

Wherein the wall thickness of the top wall 1213 is greater than the wall thickness of the first side wall 1211, whereby the structural strength of the top wall 1213 can be effectively controlled, and the heat dissipation capacity of the battery case 10 can be balanced in consideration of the relatively small heat generation of the second surface 212 of the battery cell 20 opposite to the top wall 1213.

Alternatively, the wall thickness of the top wall 1213 is equal to the wall thickness of the bottom wall 122, which not only facilitates the molding of the housing member 12, but also further controls the balance of heat dissipation.

In one embodiment, as shown in fig. 9, the cover plates 11 are two, and the two cover plates 11 are connected to opposite ends of the housing member 12; the battery also comprises two pole assemblies 30, the pole assemblies 30 are arranged on the cover plate 11, the two pole assemblies 30 are respectively arranged on the two cover plates 11, and accordingly, the battery can be electrically connected with two opposite pole lugs 23 of the battery core 20, the battery can be manufactured to a certain extent conveniently, and the manufacturing efficiency of the battery is improved.

As shown in connection with fig. 9, two cover plates 11 may be welded to opposite ends of the housing member 12, and the bottom wall 122 may be provided with a pressure relief structure 40, which, when the cells are grouped, may be arranged such that the pressure relief structure 40 is oriented towards the bottom support 70.

In one embodiment, as shown in fig. 3, the battery further includes a pressure relief structure 40, where the pressure relief structure 40 may be disposed on the bottom wall 122, so that when the internal pressure of the battery reaches a certain level, the pressure relief structure 40 may burst to avoid causing a safety problem.

When the batteries are assembled, the bottom wall 122 may be positioned toward the bottom support 70, i.e., the pressure relief structure 40, to prevent heat from striking the passenger compartment when the batteries are thermally out of control when the battery is used in a vehicle. And the relatively large thickness of the bottom wall 122 also reduces the risk of deformation of the bottom wall 122 when the pressure relief structure 40 is exploded.

The battery post assembly 30 and the pressure relief structure 40 may be provided on different surfaces of the battery case 10, and as shown in fig. 1 to 3, the post assembly 30 and the pressure relief structure 40 may be provided on the cover plate 11 and the bottom wall 122, respectively.

It should be noted that, in some embodiments, as shown in fig. 4, the post assembly 30 and the pressure relief structure 40 of the battery may be disposed on the same surface of the battery case 10, and the post assembly 30 and the pressure relief structure 40 may be disposed on the cover plate 11.

In one embodiment, the battery further includes a pressure relief structure 40, and the pressure relief structure 40 and the bottom wall 122 are integrated, so that not only the welding process can be reduced, but also the structure of the bottom wall 122 can be fully utilized, and further the utilization rate of the battery case 10 can be improved.

In one embodiment, the battery further includes a pressure relief structure 40, where the pressure relief structure 40 and the cover 11 are integrated, and on the basis of reducing the connection procedure, the formation of the pressure relief structure 40 can be controlled, so as to increase the surface utilization rate of the battery housing.

It should be noted that, the pressure relief structure 40 may be integrally formed on the battery case 10 by using a stamping process, or the pressure relief structure 40 may be integrally formed on the battery case 10 by locally thinning, for example, the pressure relief structure 40 may be formed on the battery case 10 by etching, which is not limited herein.

The pressure relief structure 40 may be formed on the cover plate 11, or the pressure relief structure 40 may be formed on the bottom wall 122, where the cover plate 11 or the bottom wall 122 cannot be too thin, and the corresponding surface of the battery case 10 is easy to deform when being formed integrally; meanwhile, the cover plate 11 or the bottom wall 122 cannot be too thick, and if too thick, the depth of stamping or etching is relatively large in order to facilitate gas release, which increases the process difficulty.

In one embodiment, as shown in fig. 2 to 4, the battery further includes a pressure relief structure 40 and a protection patch 50, the pressure relief structure 40 is disposed on the battery case 10, and the protection patch 50 is disposed on the outer surface of the battery case 10 to shield the pressure relief structure 40, so that the protection patch 50 forms protection to the pressure relief structure 40, thereby protecting the pressure relief structure 40, and further improving the service life and safety of the pressure relief structure 40.

As shown in fig. 2 to 4, the protective patch 50 is provided with a notch 51, and the notch 51 may be in a closed state in a normal state, and the notch 51 may be in an open state under a preset pressure when the air tightness of the battery is detected.

The protective patch 50 may be directly provided on the battery case 10; alternatively, the protective patch 50 may be disposed indirectly on the battery housing 10, for example, the protective patch 50 may be disposed on the pressure relief structure 40.

It should be noted that, the pressure relief structure 40 may be an explosion-proof valve in the related art, for example, the pressure relief structure 40 may be a metal sheet, the metal sheet may be welded on the battery case 10, or the metal sheet may be integrally formed on the battery case 10, which is not limited herein, and the pressure relief structure 40 may be selected according to practical requirements.

In one embodiment, the battery cell 20 includes a positive electrode plate 24 and a negative electrode plate 25, the positive electrode plate 24 includes a positive electrode current collector and a positive electrode active material layer, the negative electrode plate 25 includes a negative electrode current collector and a negative electrode active material layer, the positive electrode current collector is aluminum foil, the negative electrode current collector is copper foil, and the positive electrode current collector and the negative electrode current collector are both made of metal materials, so that the battery cell is simple in structure, convenient to mold, and convenient for heat transfer towards the bottom wall 122 and the side wall 121 along the direction perpendicular to the first surface 211 of the battery cell and the height direction of the battery cell, thereby realizing timely heat dissipation.

The opposite sides of the positive electrode current collector may be provided with positive electrode active material layers, and the opposite sides of the negative electrode current collector may be provided with negative electrode active material layers.

The pressure release structure 40 is arranged on the bottom wall 122, the positive current collector is aluminum foil, the negative current collector is copper foil, and the integral heat dissipation capacity of the battery can be effectively improved by controlling the difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 to be 0.01-1.5 mm, so that the safe use performance of the battery is improved.

In one embodiment, the battery cell 20 includes a positive electrode plate 24, a negative electrode plate 25, and a separator 26 between the positive electrode plate 24 and the negative electrode plate 25, where the heat conductivity of the separator 26 is 0.1W/(m·k) -0.8W/(m·k), so that the heat transfer of the separator 26 can be ensured, and the heat dissipation performance of the battery cell 20 is improved.

The thermal conductivity of the diaphragm 26 cannot be too poor, and the thermal conductivity of the diaphragm 26 is too poor, so that heat needs to pass through the diaphragm and the like to reach the outer surface of the battery cell and be transferred to the battery case 10, and the heat transfer is slow, which is not beneficial to improving the safety performance of the battery.

The thermal conductivity of the diaphragm 26 may be 0.1W/(m.K), 0.15W/(m.K), 0.2W/(m.K), 0.25W/(m.K), 0.3W/(m.K), 0.35W/(m.K), 0.4W/(m.K), 0.5W/(m.K), 0.55W/(m.K), 0.6W/(m.K), 0.65W/(m.K), 0.7W/(m.K), 0.75W/(m.K), or 0.8W/(m.K), and the like.

As shown in connection with fig. 7, the battery cell 20 includes a positive electrode tab 24, a negative electrode tab 25, and a separator 26 between the positive electrode tab 24 and the negative electrode tab 25, the separator 26 forming an insulating protection for the positive electrode tab 24 and the negative electrode tab 25.

In one embodiment, the battery cell 20 includes a positive electrode plate 24, a negative electrode plate 25, and a separator 26 between the positive electrode plate 24 and the negative electrode plate 25, where the ratio of the thickness of the separator 26 to the wall thickness of the first sidewall 1211 is 0.008-0.5, and on the basis of effectively controlling the separator 26 not to be damaged, the heat transfer capability of the separator 26 can be controlled, so as to improve the heat dissipation capability of the battery.

The diaphragm 26 of the battery cell 20 may be located between the positive electrode plate 24 and the negative electrode plate 25, and the diaphragm 26 may be disposed on the outer surface of the battery cell 20, where when the ratio of the thickness of the diaphragm 26 to the wall thickness of the first sidewall 1211 is too small, the diaphragm 26 is easily damaged by the inner wall of the battery case 10, which may not only damage the electrode plate, but also the negative electrode plate is generally longer than the positive electrode plate, and the negative electrode plate is closely adjacent to the diaphragm 26, and may short-circuit between the negative electrode plate and the battery case 10, thereby causing a short circuit of the battery. When the ratio of the thickness of the separator 26 to the wall thickness of the first side wall 1211 is too large, heat transfer is liable to be slow, which is disadvantageous in improving the heat dissipation capability of the battery.

The ratio of the thickness of the diaphragm 26 to the wall thickness of the first side wall 1211 may be 0.008, 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5.

In one embodiment, the thickness of the separator 26 is 8 μm-15 μm, which not only ensures the insulating and protective capabilities of the separator 26, ensures the heat transfer capabilities of the separator 26, but also prevents the thickness of the separator 26 from being too large to affect the overall energy density of the battery.

The thickness of the diaphragm 26 may be 8 μm, 8.5 μm, 9 μm, 9.5 μm, 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, 13.5 μm, 14 μm, 14.5 μm, 15 μm, or the like.

In one embodiment, the cell 20 includes a positive electrode tab 24 and a negative electrode tab 25, the positive electrode tab 24 including a positive current collector and a positive active material layer, the negative electrode tab 25 including a negative current collector and a negative active material layer; the recess 27 is formed on at least one of the positive current collector and the negative current collector, so that not only the connection strength between the current collector and the active material layer can be ensured, but also the gap between the positive electrode plate 24 and the negative electrode plate 25 can be increased, an expansion space is provided, and heat transfer is facilitated.

The surface of the positive electrode current collector opposite to the positive electrode active material layer may be provided with recesses 27, and/or the surface of the negative electrode current collector opposite to the negative electrode active material layer may be provided with recesses 27.

One side of the positive electrode current collector may be provided with a positive electrode active material layer, or both opposite sides of the positive electrode current collector may be provided with a positive electrode active material layer, at which time at least one side of the positive electrode current collector may be provided with a recess 27. One side of the anode current collector may be provided with an anode active material layer, or both opposite sides of the anode current collector may be provided with an anode active material layer, at which time at least one side of the anode current collector may be provided with a recess 27.

As shown in connection with fig. 8, a recess 27 may be provided on either the positive or negative current collector in the positive and negative electrode tabs 24 and 25, and one or more recesses 27 may be provided on either the single positive or negative current collector.

In one embodiment, the battery is a lithium iron phosphate battery, and the safety of the lithium iron phosphate battery is relatively higher on the basis of ensuring the battery capacity.

In one embodiment, the battery is a lithium iron manganese phosphate battery, so that the working voltage of the battery is wider, the voltage platform is high, the low-temperature power is better, the cost is low, and the energy density is higher.

In one embodiment, the battery is a ternary lithium battery.

In one embodiment, the battery is a ternary lithium battery, and the nickel content is less than or equal to 80%, so that the safe use performance of the battery can be effectively improved.

The battery is a ternary lithium battery, namely the battery can be a nickel-cobalt-manganese ternary battery, wherein the nickel content is less than or equal to 80%. Wherein, the ternary material can be LiNixCoyMn (1-x-y), and the nickel content is more than or equal to 80%, namely x is more than or equal to 0.8.

The positive electrode sheet 24 of the lithium iron phosphate battery includes a positive electrode active material layer, and the positive electrode active material layer includes lithium iron phosphate, mainly including lithium iron phosphate as a positive electrode main material, and may be doped with other materials such as nickel cobalt manganese, ternary materials, or materials such as lithium manganese iron. The positive electrode sheet 24 of the lithium iron manganese phosphate battery comprises a positive electrode active material layer, wherein the positive electrode active material layer comprises lithium iron manganese phosphate, mainly comprises lithium iron manganese phosphate as a positive electrode main material, and can be doped with other materials such as nickel cobalt manganese or ternary materials. The positive electrode sheet 24 of the ternary lithium battery comprises a positive electrode active material layer, wherein the positive electrode active material layer comprises a ternary material, mainly takes the ternary material as a positive electrode main material, and can be doped with other materials such as lithium iron phosphate or lithium ferromanganese.

In one embodiment, the battery is a sodium ion battery, and the sodium ion battery has a relatively low transmission rate of sodium ions due to a relatively large ion radius of sodium ions, so that ion impedance is increased, heat generation is increased, and heat transfer is facilitated, heat dissipation is timely performed, and safety use performance of the sodium ion battery is improved by enabling a difference between a wall thickness of the bottom wall 122 and a wall thickness of the first side wall 1211 to be 0.01mm-1.5 mm.

In one embodiment, the battery is a solid state battery, the solid state battery employs a solid state electrolyte, the contact area of the solid state electrolyte and the electrode material is small, the transmission speed is slow, the interface resistance is large, the internal resistance of the battery is increased, the heat generation amount is increased, and the heat dissipation capacity is improved by utilizing heat transfer by making the difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 0.01mm-1.5 mm.

In one embodiment, the battery cell 20 is a laminated battery cell, and the periphery of the laminated battery cell has an opening surface, that is, the area of the opening surface of the laminated battery cell is larger, so that heat can be quickly transferred to the battery case 10 and dissipated by the battery case 10, and the wall thickness of the first side wall 1211 is thinner, so that quick dissipation of heat is realized.

The pressure release structure 40 is disposed on the bottom wall 122, and the battery cell 20 is a laminated battery cell, and by controlling the difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 to be 0.01mm-1.5mm, the overall heat dissipation capacity of the battery can be effectively improved, and the heat dissipation capacity of the side wall 121 is increased, so that the safe use performance of the battery is improved.

The battery cell 20 includes positive pole piece 24 and negative pole piece 25, positive pole piece 24 includes positive pole current collector and positive pole active material layer, negative pole piece 25 includes negative pole current collector and negative pole active material layer, positive pole current collector is the aluminium foil, negative pole current collector is the copper foil, pressure release structure 40 sets up on diapire 122, hope that heat can concentrate and scatter and disappear from the bottom, positive current collector and negative pole current collector all adopt the metal material, the heat can reach diapire 122 fast along the current collector, the wall thickness difference of wall thickness and first side wall 1211 of simultaneous control diapire 122 is at certain scope, avoid diapire 122 too thick, be unfavorable for heat transfer, compared with other say, the current collector adopts compound form, the current collector includes polymer layer and conducting layer, the heat conduction ability of polymer layer is poor, the heat transfer is slow to the diapire, cause the heat to concentrate in the casing inside, easily cause thermal runaway.

When the pressure release structure 40 and the bottom wall 122 are integrally formed, in order to ensure that heat can be rapidly dissipated from the bottom wall 122, the difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 needs to be effectively controlled, so that the rapid dissipation of heat is ensured, and the normal explosion of the pressure release structure 40 is avoided.

It should be noted that, for the temperature of the bottom wall 122 and the first side wall 1211 of the battery, for example, a plurality of patch type temperature sensors are disposed on the bottom wall 122 and the first side wall 1211 of the battery, and are placed in an adiabatic environment, the battery is charged and discharged 2 times under the condition of 2C, the temperature of the bottom wall 122 and the first side wall 1211 of the battery, that is, the initial temperature of the bottom wall 122 and the initial temperature of the first side wall 1211 are obtained according to the temperature sensors, and the cooling temperature of the bottom wall 122 and the first side wall 1211 of the battery is obtained according to the temperature sensors, and is placed for 4 minutes. Specific test data are shown in the following table: the wall thickness of the bottom wall 122 is denoted as x (mm), the wall thickness of the first side wall 1211 is denoted as y (mm), and the area of the outer surface of the bottom wall 122 is denoted as a (mm) ² ) The area of the outer surface of the sidewall 121 is denoted as b (mm ² ) The initial temperature of the bottom wall 122 is at t1 (. Degree. C.), the initial temperature of the first side wall 1211 is denoted as t 2. Degree. C.), the cooling temperature of the bottom wall 122 is denoted as t1 (. Degree. C.), and the cooling temperature of the first side wall 1211 is denoted as t2 (. Degree. C.).

As can be seen from the above table, in embodiment 8, when the area of the outer surface of the bottom wall 122 is smaller than the area of the outer surface of the side wall 121, the heat dissipation of the bottom wall 122 is poor, and the temperature of the bottom wall 122 is high.

Embodiment 9 has a smaller area of the first side wall 1211 than embodiment 2, and the heat dissipation of the first side wall 1211 is deteriorated.

And when the difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 is excessively large, as in comparative example 1, the temperature difference between the bottom wall 122 and the bottom wall 122 is large.

In comparative example 2, the difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 is small, and the temperature difference between the bottom wall 122 and the bottom wall 122 is small, but the battery is heavy because the bottom wall 122 is thick.

An embodiment of the present utility model further provides a battery pack, including the above battery, where the battery is a plurality of batteries.

The battery pack of one embodiment of the present utility model includes a plurality of batteries including a battery case 10 and a battery cell 20, the battery cell 20 being disposed within the battery case 10, whereby the battery case 10 forms protection for the battery cell 20, and the battery cell 20 may form heat dissipation through the battery case 10. The battery case 10 includes the cover plate 11 and the case member 12, and the first side wall 1211 of the side wall 121 is disposed opposite to the first surface 211 of the battery cell 20, so that rapid heat dissipation through the first side wall 1211 is more required in consideration of the fact that the first surface 211 of the battery cell 20 generates more heat. The difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 is 0.01mm-1.5mm, i.e. the wall thickness of the bottom wall 122 is greater than the wall thickness of the first side wall 1211, so that the bottom wall 122 has enough strength to form a support for the battery cell 20, and the relatively thin first side wall 1211 can dissipate heat from the first surface 211 of the battery cell 20, so as to reduce the heat in the battery, reduce the occurrence probability of thermal runaway, and improve the safe service performance of the battery. Meanwhile, the difference between the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 is 0.01mm-1.5mm, so that the situation that the wall thickness of the bottom wall 122 and the wall thickness of the first side wall 1211 are too large, the heat dissipation of the bottom wall 122 and the side wall 121 is seriously uneven, the temperature of each side of the battery is seriously uneven is avoided, meanwhile, the situation that the weight of the battery is too large and the energy density of the battery is low due to the fact that the bottom wall 122 is too thick can be avoided.

In one embodiment, the first side walls 1211 of two adjacent batteries are disposed opposite to each other, that is, the stacking direction of the batteries may be perpendicular to the first surface 211 of the battery cell 20, which not only facilitates the improvement of space utilization, but also facilitates the rapid heat dissipation of the batteries formed by the first side walls 1211, thereby improving the safety performance of the battery pack.

In one embodiment, as shown in fig. 10, the battery pack further includes a heat exchange assembly 60; the heat exchange assembly 60 is located between two adjacent batteries, so that the heat exchange assembly 60 can quickly dissipate heat of the batteries, and the risk of thermal runaway of the battery pack is reduced.

The first side walls 1211 of two adjacent cells are disposed opposite to each other, and the heat exchange assembly 60 may be in contact with the first side walls 1211, thereby improving the heat dissipation capacity of the cells.

In one embodiment, as shown in fig. 11, the battery pack further includes a heat exchange assembly 60; the heat exchange assembly 60 is located at the bottom of the battery, so that the heat exchange assembly 60 can form a support for the battery, rapid heat dissipation of the battery can be achieved, more batteries can be arranged in the battery box body, and the capacity of the battery pack is improved.

It should be noted that, the heat exchange assembly 60 may have a flow channel therein, and the flow channel may be filled with a phase change material, or the flow channel may be provided with a gas heat exchange medium therein, or the flow channel may be provided with a liquid heat exchange medium therein, or the like.

In one embodiment, as shown in fig. 10, the battery pack further includes a bottom support 70, the battery is disposed on the bottom support 70, and the pressure release structure 40 of the battery is disposed toward the bottom support 70, so that when the battery pack is used in a vehicle, heat can be prevented from striking the passenger compartment when the battery is out of control, and the safety of a driver can be improved.

The bottom support 70 may be the bottom structure of the battery case, for example, the bottom support 70 may be the heat exchange assembly 60, or the bottom support 70 may be the bottom plate of the battery case, etc., without limitation, and the bottom support 70 may be embodied to support the battery.

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

The battery module includes a plurality of batteries, and the battery module can also include end plate and curb plate, and end plate and curb plate are used for fixed a plurality of batteries.

It should be noted that, a plurality of batteries 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 may be disposed directly in the cell case, i.e., without grouping the plurality of cells, at which time the end plates and the 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

1. A battery comprising a battery case (10) and a battery cell (20) disposed within the battery case (10), the battery cell (20) having two opposing first surfaces (211) and a second surface (212) disposed around the two first surfaces (211), the first surface (211) having an area larger than an area of the second surface (212), the battery case (10) comprising:

a cover plate (11);

-a housing part (12), said housing part (12) being connected to said cover plate (11), said housing part (12) comprising a side wall (121) and a bottom wall (122), said side wall (121) being connected to said bottom wall (122);

wherein the side wall (121) comprises a first side wall (1211) opposite the first surface (211), the difference between the wall thickness of the bottom wall (122) and the wall thickness of the first side wall (1211) being 0.01mm-1.5mm.

2. The battery according to claim 1, wherein the difference between the wall thickness of the bottom wall (122) and the wall thickness of the first side wall (1211) is 0.1mm-1mm, or the difference between the wall thickness of the bottom wall (122) and the wall thickness of the first side wall (1211) is 0.4mm-0.7mm.

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

4. The battery according to claim 1, characterized in that the thickness of the battery is 15-80 mm in a direction perpendicular to the first surface (211).

5. The battery of claim 4, wherein the thickness of the battery is 40mm-55mm.

6. The battery according to claim 1, characterized in that the wall thickness of the bottom wall (122) is 0.1-1.5 mm and/or the wall thickness of the first side wall (1211) is 0.03-1 mm.

7. The battery according to claim 6, characterized in that the wall thickness of the bottom wall (122) is 0.4-1.5 mm and/or the wall thickness of the first side wall (1211) is 0.3-0.8 mm.

8. The battery according to claim 1, wherein the cover plate (11) is arranged opposite to the bottom wall (122), the battery further comprises a post assembly (30), the post assembly (30) is arranged on the cover plate (11), the difference between the thickness of the cover plate (11) and the wall thickness of the bottom wall (122) is 0.1mm-1.9mm, and/or the difference between the thickness of the cover plate (11) and the wall thickness of the first side wall (1211) is 0.4mm-2mm.

9. The battery according to claim 8, characterized in that the difference between the thickness of the cover plate (11) and the wall thickness of the bottom wall (122) is 0.3-1.0 mm and/or the difference between the thickness of the cover plate (11) and the wall thickness of the first side wall (1211) is 0.7-1.3 mm.

10. The battery according to claim 1, further comprising a post assembly (30), the post assembly (30) being disposed on the cover plate (11), the side wall (121) comprising two opposing first side walls (1211), the side wall (121) further comprising two opposing second side walls (1212), the two ends of the second side walls (1212) being connected to the two first side walls (1211), respectively;

wherein the difference between the thickness of the cover plate (11) and the wall thickness of the second side wall (1212) is 0.3mm-1.95mm.

11. The battery according to claim 10, wherein the wall thickness of the second side wall (1212) is 0.05mm-1.2mm.

12. The battery according to claim 1, further comprising a post assembly (30), the post assembly (30) being disposed on the housing member (12).

13. The battery according to claim 1, further comprising a pressure relief structure (40), the pressure relief structure (40) being provided on the bottom wall (122).

14. The battery according to claim 1, wherein the cover plate (11) is disposed opposite to the bottom wall (122), an area of an outer surface of the bottom wall (122) is a, and an area of an outer surface of the side wall (121) is b, and 0.05-0.25 is a/b.

15. The battery according to claim 1, wherein the cover plate (11) is disposed opposite to the bottom wall (122), the side wall (121) includes two opposite first side walls (1211), the side wall (121) further includes two opposite second side walls (1212), and two ends of the second side walls (1212) are respectively connected to the two first side walls (1211);

wherein the wall thickness of the second side wall (1212) is greater than the wall thickness of the first side wall (1211), and/or the ratio of the outer surface area of the first side wall (1211) to the outer surface area of the second side wall (1212) is 2-40.

16. The battery according to claim 15, characterized in that the side wall (121) and the bottom wall (122) are of integrally formed type construction, the cover plate (11) being connected to the side wall (121).

17. The battery according to claim 1, characterized in that the side wall (121) and the bottom wall (122) are of an integrally formed structure, the cover plate (11) is connected to the side wall (121), and the cover plate (11) is disposed opposite to the bottom wall (122), or the bottom wall (122) is of an integrally formed structure with the first side wall (1211).

18. The battery according to claim 1, wherein said side walls (121) comprise two opposing first side walls (1211), said housing member (12) further comprising a top wall (1213) disposed opposite said bottom wall (122), both ends of said top wall (1213) being connected to two of said first side walls (1211), respectively;

Wherein the wall thickness of the top wall (1213) is greater than the wall thickness of the first side wall (1211), or the wall thickness of the top wall (1213) is equal to the wall thickness of the bottom wall (122).

19. The battery according to claim 18, wherein said cover plates (11) are two, and wherein two of said cover plates (11) are connected at opposite ends of said housing member (12);

the battery further comprises a pole assembly (30), the pole assembly (30) is arranged on the cover plate (11), the number of the pole assemblies (30) is two, and the pole assemblies (30) are respectively arranged on the two cover plates (11).

20. The battery according to claim 1, further comprising a pressure relief structure (40), the pressure relief structure (40) being of unitary construction with the bottom wall (122) or the pressure relief structure (40) being of unitary construction with the cover plate (11).

21. The battery according to any one of claims 2 to 19, further comprising a pressure relief structure (40), the pressure relief structure (40) being of unitary construction with the bottom wall (122) or the pressure relief structure (40) being of unitary construction with the cover plate (11).

22. The battery according to any one of claims 2 to 13, wherein the cover plate (11) is disposed opposite to the bottom wall (122), an area of an outer surface of the bottom wall (122) is a, and an area of an outer surface of the side wall (121) is b,0.05 ∈a/b ∈0.25.

23. The battery according to any one of claims 2 to 13, wherein the cover plate (11) is disposed opposite to the bottom wall (122), the side wall (121) includes two opposite first side walls (1211), the side wall (121) further includes two opposite second side walls (1212), and both ends of the second side walls (1212) are respectively connected to the two first side walls (1211);

24. The battery according to any one of claims 1 to 20, further comprising a pressure relief structure (40) and a protective patch (50), the pressure relief structure (40) being provided on the battery housing (10), the protective patch (50) being provided on an outer surface of the battery housing (10) to shield the pressure relief structure (40);

wherein, the protective patch (50) is provided with a notch (51).

25. The battery according to any one of claims 1 to 20, wherein the cell (20) comprises a positive electrode tab (24) and a negative electrode tab (25), the positive electrode tab (24) comprising a positive electrode current collector and a positive electrode active material layer, the negative electrode tab (25) comprising a negative electrode current collector and a negative electrode active material layer, the positive electrode current collector being an aluminum foil, the negative electrode current collector being a copper foil.

26. The battery according to any one of claims 1 to 20, wherein the cell (20) comprises a positive electrode tab (24), a negative electrode tab (25) and a separator (26) between the positive electrode tab (24) and the negative electrode tab (25), the separator (26) having a thermal conductivity of 0.1W/(m-K) to 0.8W/(m-K).

27. The battery according to any one of claims 1 to 20, wherein the cell (20) comprises a positive electrode tab (24), a negative electrode tab (25) and a separator (26) between the positive electrode tab (24) and the negative electrode tab (25), the ratio of the thickness of the separator (26) to the wall thickness of the first side wall (1211) being 0.008-0.5.

28. The battery according to claim 27, wherein the separator (26) has a thickness of 8-15 μm.

29. The battery according to any one of claims 1 to 20, wherein the cell (20) comprises a positive electrode tab (24) and a negative electrode tab (25), the positive electrode tab (24) comprising a positive current collector and a positive active material layer, the negative electrode tab (25) comprising a negative current collector and a negative active material layer;

wherein a surface of the positive electrode current collector opposite to the positive electrode active material layer is provided with a recess (27), and/or a surface of the negative electrode current collector opposite to the negative electrode active material layer is provided with a recess (27).

30. The battery according to any one of claims 1 to 20, wherein the battery is a lithium iron phosphate battery, or the battery is a lithium manganese iron phosphate battery, or the battery is a sodium ion battery, or the battery is a solid state battery, or the battery is a ternary lithium battery, and the nickel content is equal to or less than 80%.

31. The battery according to any one of claims 1 to 20, wherein the cells (20) are laminated cells.

32. A battery comprising a plurality of cells as claimed in any one of claims 1 to 31.

33. The battery according to claim 32, wherein said first side walls (1211) of adjacent two of said cells are oppositely disposed.

34. The battery according to claim 32 or 33, wherein the battery further comprises a heat exchange assembly (60);

wherein the heat exchange assembly (60) is positioned between two adjacent batteries, or the heat exchange assembly (60) is positioned at the bottom of the batteries.

35. The battery according to claim 32 or 33, further comprising a bottom support (70), the battery being arranged on the bottom support (70), the pressure relief structure (40) of the battery being arranged towards the bottom support (70).