Battery pack and electric device

Abstract

The embodiments of the present invention relate to the field of battery technology, and in particular to a battery pack and an electrical device, wherein the battery pack includes at least two stacked battery cells and an elastic member disposed between two adjacent battery cells; the battery cell includes a body and a tab, the body includes a head, a middle portion and a tail portion connected in sequence, the tab extends from the head portion, wherein in the direction of stacking of the battery cells, the thickness of the middle portion is greater than the thickness of the head portion, and the thickness of the middle portion is greater than the thickness of the tail portion; the elastic member includes a first elastic member and a second elastic member; the first elastic member is disposed between the middle portions of two adjacent battery cells; the second elastic member is disposed between the heads of two adjacent battery cells; the elastic coefficient of the first elastic member is less than the elastic coefficient of the second elastic member. When the battery cell expands, compared with the case where the elastic coefficients of the elastic member are equal, the buffering force of the elastic member on the head of the battery cell is greater, the head of the battery cell is not easily deformed, and the performance of the battery pack is good.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of battery technology, and in particular to a battery pack and an electrical device. Background Art

[0002] A battery pack is a device that converts electrical energy into chemical energy, and when electrical energy is needed, it converts chemical energy back into electrical energy to power electronic devices. That is, the battery pack can be charged and discharged. With the rapid growth of mobile electronic devices, the demand for battery packs has increased rapidly, and the research and application of battery packs have also increased. The battery pack includes a number of stacked cells, and the cells will expand during the charging and discharging process of the battery pack. In order to suppress the expansion of the cells, an elastic member is provided between two adjacent cells.

[0003] The inventors of the present invention discovered during the process of implementing the present invention that: at present, the thickness of the elastic part is uniform, the elastic coefficient is uniform, the thickness of the head of the battery cell is smaller than the thickness of the middle part of the battery cell, and when the elastic coefficient of the elastic part is uniform, the buffering force of the elastic part on the head of the battery cell is small, and the head of the battery cell is prone to bulging, warping or other deformation, thereby causing lithium deposition and other situations that affect the performance of the battery pack. Summary of the invention

[0004] In view of the above problems, embodiments of the present invention provide a battery pack and an electrical device, which overcome the above problems or at least partially solve the above problems.

[0005] According to one aspect of an embodiment of the present invention, there is provided a battery pack, comprising at least two stacked battery cells, and an elastic member arranged between two adjacent battery cells; the battery cell comprises a main body and a tab, the main body comprises a head, a middle portion and a tail portion connected in sequence, the tab extends from the head, wherein in the direction in which the battery cells are stacked, the thickness of the middle portion is greater than the thickness of the head, and the thickness of the middle portion is greater than the thickness of the tail; the elastic member comprises a first elastic portion and a second elastic portion; the first elastic portion is arranged between the middle portions of two adjacent battery cells; the second elastic portion is arranged between the heads of two adjacent battery cells; the elastic coefficient of the first elastic portion is smaller than the elastic coefficient of the second elastic portion.

[0006] In an optional manner, in the direction of stacking the battery cells, the thickness of the second elastic portion is greater than or equal to the thickness of the first elastic portion; the elastic coefficient of the first elastic portion is K1', the elastic coefficient of the second elastic portion is K2', and when the thickness of the second elastic portion is equal to the thickness of the first elastic portion, 100:98≤K2':K1'≤100:85.

[0007] In an optional manner, when the thickness of the second elastic portion is equal to the thickness of the first elastic portion, 100:95≤K2′:K1′≤100:90.

[0008] In an optional manner, when the thickness of the second elastic portion is equal to the thickness of the first elastic portion, 100:92≤K2′:K1′≤100:90.

[0009] In an optional manner, the elastic coefficient is calculated as follows: K=δF / δL, wherein K is the elastic coefficient, δF is the stress on the object, and δL is the strain generated when the object is subjected to stress.

[0010] In an optional manner, the first elastic portion and the second elastic portion are made of the same material, have the same thickness in the direction of stacking the battery cells, and have different densities.

[0011] In an optional manner, the first elastic portion and the second elastic portion are made of the same material, have the same density, and have unequal thicknesses in the direction in which the battery cells are stacked.

[0012] In an optional manner, the first elastic portion and the second elastic portion are connected to each other, or the first elastic portion and the second elastic portion are integrally formed.

[0013] In an optional manner, the elastic member further includes a third elastic portion, the third elastic portion is disposed between tail portions of two adjacent battery cells, and the elastic coefficient of the first elastic portion is smaller than the elastic coefficient of the third elastic portion.

[0014] In an optional manner, in the direction of stacking the battery cells, the thickness of the third elastic part is greater than or equal to the thickness of the first elastic part; the elastic coefficient of the first elastic part is K1', the elastic coefficient of the third elastic part is K3', and when the thickness of the third elastic part is equal to the thickness of the first elastic part, 100:98≤K2':K1'≤100:85.

[0015] In an optional manner, when the thickness of the third elastic portion is equal to the thickness of the first elastic portion, 100:95≤K2′:K1′≤100:90.

[0016] In an optional manner, when the thickness of the third elastic portion is equal to the thickness of the first elastic portion, 100:92≤K2′:K1′≤100:90.

[0017] In an optional manner, the third elastic portion and the second elastic portion are integrally formed.

[0018] In an optional manner, the second elastic part is provided with a first groove, the third elastic part is provided with a second groove, the first groove and the second groove together form a mounting hole, and the first elastic part is installed in the mounting hole.

[0019] In an optional manner, at least one of the side walls of the first groove and the side walls of the second groove is provided with a first matching structure, and the first elastic part is provided with a second matching structure, and the first matching structure and the second matching structure cooperate together to fix the first elastic part in the mounting hole.

[0020] In an optional manner, the first mating structure and the second mating structure are both serrations, wherein the serrations of at least one of the second elastic part and the third elastic part mesh with the serrations of the first elastic part, or the first mating structure is a fixing groove provided on at least one of the side walls of the first groove and the side walls of the second groove, and the second mating structure is a fixing strip extending from the edge of the first elastic part, and the fixing strip is inserted into the fixing groove.

[0021] In an optional manner, the elastic members are all foam.

[0022] In an optional manner, the second elastic portion protrudes from the head of the battery cell.

[0023] In an optional manner, the third elastic portion protrudes from the tail of the battery cell.

[0024] According to one aspect of an embodiment of the present invention, there is provided an electric device, comprising a load and the above-mentioned battery pack, wherein the battery pack is used to supply power to the load.

[0025] The beneficial effect of the embodiments of the present invention is that a battery pack and an electrical device are provided, wherein when a battery cell in the battery pack expands, although the expansion amount of the head of the battery cell is small, since the elastic coefficient of the second elastic part of the elastic part arranged between the heads of two adjacent battery cells is greater than the elastic coefficient of the first elastic part of the elastic part arranged between the middle parts of two adjacent battery cells, compared with the case where the elastic coefficients of the elastic parts are equal, when the battery cell expands, the buffering force of the elastic part on the head of the battery cell is large, the head of the battery cell is not easily deformed, and the performance of the battery pack is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of a battery pack provided by an embodiment of the present invention;

[0027] Figure 2 is an exploded schematic diagram of a battery pack provided by an embodiment of the present invention;

[0028] Figure 3is a schematic diagram of a battery cell provided by an embodiment of the present invention;

[0029] Figure 4 Schematic diagram of an implementation method of the elastic member provided in an embodiment of the present invention

[0030] Figure 5 is another exploded schematic diagram of a battery pack provided by an embodiment of the present invention;

[0031] Figure 6 is a force analysis diagram of a battery cell provided by an embodiment of the present invention;

[0032] Figure 7 is a force analysis diagram of an elastic member in a battery pack provided by an embodiment of the present invention;

[0033] Figure 8 is a schematic diagram of another implementation of the elastic member provided in an embodiment of the present invention;

[0034] Fig. 9 It is a schematic diagram of another implementation of the elastic member provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] For ease of understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on another element, or there can be one or more centered elements therebetween. When an element is described as "connected to" another element, it can be directly connected to another element, or there can be one or more centered elements therebetween. The terms "vertical", "horizontal", "left", "right", "inside", "outside" and similar expressions used in this specification are for illustrative purposes only.

[0036] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0037] See also Figure 1 and Figure 2 The battery pack includes: at least two stacked battery cells 10 and an elastic member 20, wherein the elastic member 20 is located between two adjacent battery cells 10, and when the battery cell 10 expands, the elastic member 20 is used to buffer it.

[0038] For the above cell 10, please refer to Figure 3The battery cell 10 includes a body 101 and a tab 102. The body 101 includes a middle portion 1011, a head portion 1012 and a tail portion 1013 connected in sequence. The tab 102 extends from the head portion 1012 of the body 101. The tail portion 1013 is located at one end of the body 101 away from the tab 102.

[0039] It should be noted that when at least two battery cells 10 are stacked, the head portions 1012 of the at least two battery cells 10 are disposed opposite to each other, and the tail portions 1013 of the at least two battery cells 10 are disposed opposite to each other.

[0040] For the elastic member 20, please refer to Figure 4 and Figure 5 The elastic member 20 includes a first elastic portion 201, a second elastic portion 202 and a third elastic portion 203. The first elastic portion 201 is disposed between the middle portions 1011 of two adjacent battery cells 10. The second elastic portion 202 is disposed between the head portions 1012 of two adjacent battery cells 10. The third elastic portion 203 is disposed between the tail portions 1013 of two adjacent battery cells 10. The elastic coefficient of the first elastic portion 201 is smaller than the elastic coefficient of the second elastic portion 202. The elastic coefficient of the first elastic portion 201 is smaller than the elastic coefficient of the third elastic portion 203.

[0041] The elastic coefficient calculation formula is:

[0042] K=δF / δL

[0043] Among them, K is the elastic coefficient, δF is the stress on the object, and δL is the strain generated when the object is subjected to stress.

[0044] That is, the modulus of elasticity is the ratio of the stress to the strain experienced by an object.

[0045] The elastic coefficient K and the stress δF have the same unit, for example, Pascal, kilopascal or megapascal.

[0046] In the present application, according to the relationship that the action force is equal to the reaction force, the stress exerted on the first elastic part 201 is the expansion force generated by the middle part 1011 when the battery cell 10 expands. The first elastic part 201 generates a buffering force to counteract the expansion force exerted on it by the battery cell 10. The buffering force of the first elastic part 201 is equal to the expansion force of the middle part 1011 when the battery cell 10 expands. The elastic coefficient of the first elastic part 201 is the ratio of the buffering force of the first elastic part 201 to its deformation.

[0047] It should be noted that in this application, all "equal" can be carried out according to the national standard. In the national standard, "equal" is divided into fine, medium and rough, etc., and the specific one can be selected according to the actual product needs. In addition, "equal" can also be an allowable value marked by the product designer.

[0048] In the present application, according to the relationship that the action force is equal to the reaction force, the stress on the second elastic part 202 is the expansion force generated by the head 1012 of the battery cell 10 when the battery cell 10 expands. The second elastic part 202 generates a buffering force to counteract the expansion force applied by the battery cell 10. The buffering force of the second elastic part 202 is equal to the expansion force of the head 1012 of the battery cell 10 when the battery cell 10 expands. The elastic coefficient of the second elastic part 202 is the ratio of the buffering force of the second elastic part 202 to its deformation.

[0049] In the present application, according to the relationship that the action force is equal to the reaction force, the stress exerted on the third elastic part 203 is the expansion force generated by the tail 1013 of the battery cell 10 when the battery cell 10 expands. The third elastic part 203 generates a buffering force to counteract the expansion force exerted on it by the battery cell 10. The buffering force of the third elastic part 203 is equal to the expansion force of the tail 1013 of the battery cell 10 when the battery cell 10 expands. The elastic coefficient of the third elastic part 203 is the ratio of the buffering force of the third elastic part 203 to its deformation.

[0050] When the battery cell 10 expands, the thickness of the battery cell 10 increases in the direction in which the battery cells 10 are stacked, and the battery cell 10 applies a force to the elastic member 20, and the elastic member 20 is compressed. At the same time, the elastic member 20 generates a buffer force to counteract the force applied to it by the battery cell 10. In other words, the buffer force is the reaction force generated by the elastic member 20 to counteract the force applied to it by the battery cell 10.

[0051] The elastic member 20 includes a first elastic portion 201 , a second elastic portion 202 and a third elastic portion 203 . When the battery cell 10 expands, the first elastic portion 201 , the second elastic portion 202 and the third elastic portion 203 will respectively generate buffering forces to resist the force exerted on them by the battery cell 10 .

[0052] It should be noted that, in some embodiments, the third elastic portion 203 may not be provided, or although the third elastic portion 203 is provided, the elastic coefficient of the third elastic portion 203 is equal to the elastic coefficient of the first elastic portion 201 .

[0053] See also Figure 6 , Figure 6 1 is a force analysis diagram of a battery cell provided by an embodiment of the present invention. When the battery cell 10 expands, the relationship between the expansion force of the middle portion 1011, the expansion coefficient of the middle portion 1011 and the expansion amount of the middle portion 1011 is:

[0054] F1=K1*ΔT1

[0055] Wherein, F1 is the expansion force of the middle portion 1011 , K1 is the expansion coefficient of the middle portion 1011 , and ΔT1 is the expansion amount of the middle portion 1011 .

[0056] When the battery cell 10 expands, the relationship between the expansion force of the head 1012, the expansion coefficient of the head 1012, and the expansion amount of the head 1012 is:

[0057] F2=K2*ΔT2

[0058] Among them, F2 is the expansion force of the head 1012, K2 is the expansion coefficient of the head 1012, and ΔT2 is the expansion amount of the head 1012.

[0059] See also Figure 7 , Figure 7 is a force analysis diagram of the elastic member provided by an embodiment of the present invention. When the battery cell 10 expands, the relationship between the buffering force of the first elastic part 201 in contact with the battery cell 10, the elastic coefficient of the first elastic part 201 and the deformation of the first elastic part 201 is:

[0060] F1'=K1'*ΔT1'

[0061] Wherein, F1' is the buffer force of the first elastic part 201, K1' is the elastic coefficient of the first elastic part 201, and ΔT1' is the deformation of the first elastic part 201. According to the relationship between the action force and the reaction force, the expansion force F1 of the middle part 1011 is equal to the buffer force F1' of the first elastic part 201, and the expansion amount ΔT1 of the middle part 1011 is equal to the deformation amount ΔT1' of the first elastic part 201. When the battery cell 10 expands, the relationship between the buffer force of the second elastic part 202 in contact with the battery cell 10, the elastic coefficient of the second elastic part 202, and the deformation of the second elastic part 202 is:

[0062] F2'=K2'*ΔT2'

[0063] Wherein, F2' is the buffer force of the second elastic part 202, K2' is the elastic coefficient of the second elastic part 202, and ΔT2' is the deformation of the second elastic part 202. According to the relationship between the action force and the reaction force, the expansion force F2 of the head 1012 is equal to the buffer force F2' of the second elastic part 202, and the expansion amount ΔT2 of the head 1012 is equal to the deformation amount ΔT2' of the first elastic part 201.

[0064] It should be noted that when the battery cell 10 expands, the expansion amount ΔT1 of the middle part 1011 is greater than the expansion amount ΔT2 of the head part 1012, and the deformation amount ΔT1' of the first elastic part 201 is greater than the deformation amount ΔT2' of the second elastic part 202. If the elastic coefficient K1' of the first elastic part 201 and the elastic coefficient K2' of the second elastic part 202 are equal, the buffering force of the first elastic part 201 is greater than the buffering force of the second elastic part 202, that is, the force on the head part 1012 is less than the force on the middle part 1011, and the head part 1012 is easy to deform. In the embodiment of the present invention, the elastic coefficient K2' of the second elastic part 202 is greater than the elastic coefficient K1' set in the first elastic part 201, then compared with the case where the elastic coefficients of the elastic member 20 are equal, the buffering force of the second elastic member 202 on the head part 1012 is greater, and the expansion of the head part 1012 of the battery cell 10 is suppressed by the elastic member 20 and is not easy to deform.

[0065] It is worth noting that, in the direction in which the battery cells 10 are stacked, the thickness of the second elastic portion 202 is greater than or equal to the thickness of the first elastic portion 201. In some embodiments, in the direction in which the battery cells 10 are stacked, the ratio of the thickness difference between the middle portion 1011 and the head portion 1012 of the battery cell 10 to the thickness of the middle portion 1011 is between 2% and 15%, and when the thickness of the second elastic portion 202 is equal to the thickness of the first elastic portion 201, the elastic coefficient of the first elastic portion 201 is K1', and the elastic coefficient of the second elastic portion 202 is K2', which satisfies: 100:98≤K2':K1'≤100:85.

[0066] It is worth noting that, in some embodiments, in the direction in which the battery cells 10 are stacked, the ratio of the thickness difference between the middle portion 1011 and the head portion 1012 of the battery cell 10 to the thickness of the middle portion 1011 is between 5% and 10%, and when the thickness of the second elastic portion 202 is equal to the thickness of the first elastic portion 201, the elastic coefficient of the first elastic portion 201 is K1', and the elastic coefficient of the second elastic portion 202 is K2', which satisfies: 100:95≤K2':K1'≤100:90.

[0067] It is worth noting that, in some embodiments, in the direction in which the battery cells 10 are stacked, the ratio of the thickness difference between the middle portion 1011 and the head portion 1012 of the battery cell 10 to the thickness of the middle portion 1011 is 8%, and when the thickness of the second elastic portion 202 is equal to the thickness of the first elastic portion 201, the elastic coefficient K2' of the second elastic portion 202 and the elastic coefficient K1' of the first elastic portion 201 satisfy: K2': K1'≥100:92.

[0068] It should be noted that when the elastic member 20 includes the third elastic portion 203, the elastic coefficient of the first elastic portion 201 is smaller than the elastic coefficient of the third elastic portion 203. Compared with the case where the elastic coefficients of the elastic member 20 are equal, the buffering force of the third elastic portion 203 on the tail portion 1013 is greater, and the expansion of the tail portion 1013 of the battery cell 10 is suppressed by the elastic member 20 and is not easily deformed.

[0069] It is worth noting that, in the direction in which the battery cells 10 are stacked, the thickness of the third elastic portion 203 is greater than or equal to the thickness of the first elastic portion 201. In some embodiments, in the direction in which the battery cells 10 are stacked, the ratio of the thickness difference between the middle portion 1011 and the tail portion 1013 of the battery cell 10 to the thickness of the middle portion 1011 is between 2% and 15%, and when the thickness of the third elastic portion 203 is equal to the thickness of the first elastic portion 201, the elastic coefficient of the first elastic portion 201 is K1', and the elastic coefficient of the third elastic portion 203 is K2', which satisfies: 100:98≤K2':K1'≤100:85.

[0070] It is worth noting that, in some embodiments, in the direction in which the battery cells 10 are stacked, the ratio of the thickness difference between the middle portion 1011 and the tail portion 1013 of the battery cell 10 to the thickness of the middle portion 1011 is between 5% and 10%, and when the thickness of the third elastic portion 203 is equal to the thickness of the first elastic portion 201, the elastic coefficient of the first elastic portion 201 is K1', and the elastic coefficient of the third elastic portion 203 is K2', which satisfies: 100:95≤K2':K1'≤100:90.

[0071] It is worth noting that, in some embodiments, in the direction in which the battery cells 10 are stacked, the ratio of the thickness difference between the middle portion 1011 and the tail portion 1013 of the battery cell 10 to the thickness of the middle portion 1011 is 8%, and when the thickness of the third elastic portion 203 is equal to the thickness of the first elastic portion 201, the elastic coefficient K3' of the third elastic portion 203 and the elastic coefficient K1' of the first elastic portion 201 satisfy: 100:92≤K2':K1'≤100:90.

[0072] In some embodiments, the elastic coefficient of the third elastic portion 203 may be equal to the elastic coefficient of the second elastic portion 202 .

[0073] In some embodiments, the elastic member 20 is foam, that is, the materials of the first elastic part 201, the second elastic part 202 and the third elastic part 203 are all foam. The materials of the first elastic part 201, the second elastic part 202 and the third elastic part 203 can be selected from one or more of modified polypropylene (MPP), modified polyphenylene ether (MPPE), nonylphenol polyoxyethylene ether (NPE), ethylene-vinyl acetate copolymer (EVA), chloroprene rubber (CR) and silicone materials.

[0074] It should be noted that the elastic coefficient of the first elastic portion 201 is related to at least one of its material, density, and thickness in the direction in which the battery cells 10 are stacked. The elastic coefficient of the second elastic portion 202 is related to at least one of its material, density, and thickness in the direction in which the battery cells 10 are stacked. The elastic coefficient of the third elastic portion 203 is related to at least one of its material, density, and thickness in the direction in which the battery cells 10 are stacked.

[0075] In some embodiments, the first elastic portion 201 and the second elastic portion 202 are made of the same material, have the same thickness in the stacking direction of the battery cells 10 , and have different densities.

[0076] In some embodiments, the first elastic portion 201 and the third elastic portion 203 are made of the same material, have the same thickness in the stacking direction of the battery cells 10 , and have different densities.

[0077] In some embodiments, the first elastic portion 201 and the second elastic portion 202 are made of the same material, have the same density, and have unequal thicknesses in the stacking direction of the battery cells 10 .

[0078] In some embodiments, the first elastic portion 201 and the third elastic portion 203 are made of the same material, have the same density, and have different thicknesses in the stacking direction of the battery cells 10 .

[0079] In some embodiments, the first elastic portion 201 and the second elastic portion 202 are made of different materials, have the same density, and have the same thickness in the stacking direction of the battery cells 10 .

[0080] In some embodiments, the first elastic portion 201 and the third elastic portion 203 are made of different materials, have the same density, and have the same thickness in the stacking direction of the battery cells 10 .

[0081] For example, when the second elastic part 202 and the first elastic part 201 are selected from the same material, the density of the second elastic part 202 is greater than the density of the first elastic part 201, and / or, in the direction in which the battery cells 10 are stacked, the thickness of the second elastic part 202 is greater than the thickness of the first elastic part 201. It should be noted that the present application does not specifically limit the material, density and thickness of the second elastic part 202 and the first elastic part 201, but it is required that the elastic coefficient of the second elastic part 202 is greater than the elastic coefficient of the first elastic part 201.

[0082] For example, when the third elastic portion 203 and the first elastic portion 201 are selected from the same material, the density of the third elastic portion 203 is greater than the density of the first elastic portion 201, and / or, in the direction in which the battery cells 10 are stacked, the thickness of the third elastic portion 203 is greater than the thickness of the first elastic portion 201.

[0083] It should be noted that the present application does not specifically limit the material, density and thickness of the third elastic part 203 and the first elastic part 201 , but it is only necessary that the elastic coefficient of the third elastic part 203 is greater than the elastic coefficient of the first elastic part 201 .

[0084] See also Figure 7 The second elastic part 202 of the elastic member 20 may be arranged to protrude from the head 1012 of the battery cell 10, and the third elastic part 203 of the elastic member 20 may be arranged to protrude from the tail 1013 of the battery cell 10. Due to long-term immersion in the electrolyte, the electrode sheets at the head 1012 of the battery cell 10 and the tail 1013 of the battery cell 10 are prone to soften. When the battery cell 10 expands, if it cannot obtain good buffering from the elastic member 20, it is easy to warp and deform, thereby increasing the distance between the cathode and anode of the battery cell 10, causing cycle diving. When the elastic coefficient of the second elastic portion 202 of the elastic member 20 arranged between the heads 1012 of two adjacent battery cells 10 is greater than the elastic coefficient of the first elastic portion 201 of the elastic member 20 arranged between the middle portions 1011 of two adjacent battery cells 10, the buffering force applied to the heads 1012 of the battery cells 10 is large, and the heads 1012 of the battery cells 10 are not easily deformed. When the second elastic portion 202 of the elastic member 20 can be arranged to protrude from the heads 1012 of the battery cells 10, the heads 1012 of the battery cells 10 are less likely to deform. When the elastic coefficient of the third elastic portion 203 of the elastic member 20 disposed between the tail portions 1013 of two adjacent battery cells 10 is greater than the elastic coefficient of the first elastic portion 201 of the elastic member 20 disposed between the middle portions 1011 of two adjacent battery cells 10, the buffering force applied to the tail portion 1013 of the battery cell 10 is large, and the tail portion 1013 of the battery cell 10 is not easily deformed. When the third elastic portion 203 of the elastic member 20 can be disposed to protrude from the tail portion 1013 of the battery cell 10, the tail portion 1013 of the battery cell 10 is even less likely to deform.

[0085] It should be noted that the elastic part 20 includes a first elastic part 201, a second elastic part 202 and a third elastic part 203, wherein the first elastic part 201 and the second elastic part 202 are interconnected or integrally formed, wherein the third elastic part 203 and the second elastic part 202 are interconnected or integrally formed, wherein the second elastic part 202 and the third elastic part 203 are integrally formed, wherein the first elastic part 201, the second elastic part 202 and the third elastic part 203 are interconnected or integrally formed, and the first elastic part 201, the second elastic part 202 and the third elastic part 203 in the elastic part 20 can be implemented in multiple ways.

[0086] See also Figure 4 One implementation of the elastic member 20 is that the second elastic part 202 is provided with a first groove 2021, the third elastic part 203 is provided with a second groove 2031, the first groove 2021 and the second groove 2031 are surrounded by a mounting hole 202s, and the first elastic part 201 is mounted in the mounting hole 202s. The cross-section of the mounting hole 202s may be rectangular, circular, spindle-shaped, semicircular, etc., which is not specifically limited in the embodiment of the present invention.

[0087] Please note that Figure 3 and Figure 5 The central axis of the mounting hole 202s can be along the stacking direction of the battery cells 10, or can have a preset angle with the stacking direction of the battery cells 10, or have a preset angle with the direction of the line connecting the head 1012 and the tail 1013 of the battery cell 10, as long as the first elastic portion 201 is located between the middle portions 1011 of two adjacent battery cells 10, the second elastic portion 202 is located between the heads 1012 of two adjacent battery cells 10, the third elastic portion 203 is located between the tails 1013 of two adjacent battery cells 10, and the elastic coefficient of the second elastic portion 202 is greater than the elastic coefficient of the first elastic portion 201, and the elastic coefficient of the third elastic portion 203 is greater than the elastic coefficient of the first elastic portion 201.

[0088] It is understandable that the first elastic portion 201 is installed in the installation hole 202s, and the first elastic portion 201 does not necessarily need to be flush with the second elastic portion 202, that is, the first elastic portion 201 can be recessed in the installation hole 202s.

[0089] See also Figure 5 When the central axis of the mounting hole 202s is the same as the stacking direction of the battery cells 10, or the central axis of the mounting hole 202s is perpendicular to the stacking direction of the battery cells 10 and perpendicular to the connecting direction of the head 1012 and the tail 1013 of the battery cell 10, the opposite ends of the first elastic portion 201 may be respectively recessed into the mounting hole 202s by a preset distance. In some embodiments, the preset distance is 1% of the length of the second elastic portion 202 in the direction of the central axis of the mounting hole 202s.

[0090] The first elastic portion 201 may be directly inserted into the mounting hole 202s, or may be adhered to the mounting hole 202s by adhesive, or, see Figure 8 At least one of the sidewalls of the first groove 2021 and the sidewalls of the second groove 2031 is provided with a first matching structure 203s, and the first elastic part 201 is provided with a second matching structure 2011. The first matching structure 203s and the second matching structure 2011 cooperate to fix the first elastic part 201 in the mounting hole 202s. The first elastic part 201, the second elastic part 202 and the third elastic part 203 are installed by adhesive or by the first matching structure 203s and the second matching structure 2011. When the battery cell 10 expands, the elastic member 20 is squeezed by the battery cell 10, and the first elastic part 201, the second elastic part 202 and the third elastic part 203 are not easy to slide relative to each other.

[0091] In some embodiments, see Figure 8 The first matching structure 203s and the second matching structure 2011 are both serrations, wherein the serrations of at least one of the second elastic portion 202 and the third elastic portion 203 are meshed with the serrations of the first elastic portion 201, or the first matching structure 203s is a fixing groove (not shown) arranged on the side wall of the first groove 2021 and at least one of the side walls of the second groove 2031, and the second matching structure 2011 is a fixing strip (not shown) extending from the edge of the first elastic portion 201, and the fixing strip is inserted into the fixing groove.

[0092] See also Fig. 9 Another implementation method of the elastic member 20 is that one end of the first elastic portion 201 is recessed to form a first mounting groove 2012, and the other end of the first elastic portion 201 is recessed to form a second mounting groove 2013, the second mounting groove 2013 is opposite to the first mounting groove 2012, the second elastic portion 202 is installed in the first mounting groove 2012, and the third elastic portion 203 is installed in the second mounting groove 2013.

[0093] It can be understood that the second elastic part 202 and the third elastic part 203 can be directly plugged in, bonded by an adhesive, or installed in the first mounting groove 2012 and the second mounting groove 2013 through a matching structure. The first groove 2021 is set for the second elastic part 202, the second groove 2031 is set for the third elastic part 203, the first groove 2021 and the second groove 2031 are combined to form a mounting hole 202s, and the first elastic part 201 is installed in the mounting hole 202s for setting, which will not be repeated here.

[0094] In an embodiment of the present invention, a battery pack includes at least two stacked battery cells 10 and an elastic member 20, wherein the battery cell 10 includes a main body 101 and a tab 102. The main body 101 includes a middle portion 1011, a head portion 1012, and a tail portion 1013. The tab 102 extends from the head portion 1012 of the main body 101, and the tail portion 1013 is located at an end of the main body 101 away from the tab 102. The elastic member 20 includes a first elastic portion 201 and a second elastic portion 202. The first elastic portion 201 is located between the middle portions 1011 of two adjacent battery cells 10, and the second elastic portion 202 is located between the heads 1012 of two adjacent battery cells 10. The elastic coefficient of the first elastic portion 201 is less than the elastic coefficient of the second elastic portion 202. When the battery cell 10 in the battery pack expands, although the expansion amount of the head 1012 is small, since the elastic coefficient of the second elastic part 202 is greater than the elastic coefficient of the first elastic part 201, compared with the case where the elastic coefficients of the elastic part 20 are equal, when the battery cell 10 expands, the buffering force of the elastic part 20 on the head of the battery cell 10 is large, the head of the battery cell 10 is not easily deformed, and the performance of the battery pack is good.

[0095] The embodiment of the present invention further provides an embodiment of an electric device, the electric device comprising a load and the above-mentioned battery pack. The battery pack is used to supply power to the load. The specific structure and function of the battery pack can be referred to the above-mentioned embodiment, which will not be described one by one here.

[0096] Electrical equipment can be energy storage products, drones, electric vehicles with one or more wheels, or electric tools, etc.

[0097] For example, for the above-mentioned drone, the battery pack is mounted on the drone, and the battery pack is used to power loads on the drone including a flight system, a control system, and a camera system.

[0098] It should be noted that the preferred embodiments of the present invention are given in the specification and drawings of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. These embodiments are not used as additional limitations on the content of the present invention. The purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. In addition, the above-mentioned technical features continue to be combined with each other to form various embodiments not listed above, which are all regarded as the scope of the present invention; further, for ordinary technicians in this field, they can be improved or transformed according to the above description, and all these improvements and transformations should belong to the protection scope of the claims attached to the present invention.

Claims

1. A battery pack, comprising at least two stacked cells, and an elastic member disposed between two adjacent cells; the cell comprises a body and a tab, the body comprising a head, a middle and a tail connected in sequence, the tab extending from the head, wherein: In the direction of stacking the battery cells, the thickness of the middle portion is greater than the thickness of the head portion, and the thickness of the middle portion is greater than the thickness of the tail portion; It is characterized in that The elastic member comprises a first elastic portion and a second elastic portion, wherein the first elastic portion and the second elastic portion are connected to each other; The first elastic portion is arranged between the middle portions of two adjacent battery cells; The second elastic portion is arranged between the heads of two adjacent battery cells; The elastic coefficient of the first elastic part is smaller than the elastic coefficient of the second elastic part; The calculation formula of the elastic coefficient is: in, is the elastic coefficient, is the stress on the object, The strain produced when an object is subjected to stress.

2. The battery pack according to claim 1, characterized in that: In the stacking direction of the battery cells, the thickness of the second elastic portion is greater than or equal to the thickness of the first elastic portion; The elastic coefficient of the first elastic part is , the elastic coefficient of the second elastic part is , when the thickness of the second elastic portion is equal to the thickness of the first elastic portion, .

3. The battery pack according to claim 2, characterized in that: When the thickness of the second elastic portion is equal to the thickness of the first elastic portion, .

4. The battery pack according to claim 3, characterized in that: When the thickness of the second elastic portion is equal to the thickness of the first elastic portion, .

5. The battery pack according to claim 1, characterized in that: The first elastic portion and the second elastic portion are made of the same material, have the same thickness in the direction in which the battery cells are stacked, and have different densities.

6. The battery pack according to claim 1, characterized in that: The first elastic portion and the second elastic portion are made of the same material, have the same density, and have unequal thicknesses in the direction in which the battery cells are stacked.

7. The battery pack according to claim 1, characterized in that: The first elastic portion and the second elastic portion are integrally formed.

8. The battery pack according to claim 1, characterized in that: The elastic member further includes a third elastic portion, which is disposed between the tails of two adjacent battery cells, and the elastic coefficient of the first elastic portion is smaller than the elastic coefficient of the third elastic portion.

9. The battery pack according to claim 8, characterized in that: In the stacking direction of the battery cells, the thickness of the third elastic portion is greater than or equal to the thickness of the first elastic portion; The elastic coefficient of the first elastic part is , the elastic coefficient of the third elastic part is , when the thickness of the third elastic portion is equal to the thickness of the first elastic portion, .

10. The battery pack according to claim 9, characterized in that: When the thickness of the third elastic portion is equal to the thickness of the first elastic portion, .

11. The battery pack according to claim 10, characterized in that: When the thickness of the third elastic portion is equal to the thickness of the first elastic portion, .

12. The battery pack according to claim 8, characterized in that: The third elastic portion and the second elastic portion are integrally formed.

13. The battery pack according to claim 8, characterized in that: The second elastic part is provided with a first groove, the third elastic part is provided with a second groove, the first groove and the second groove are combined to form a mounting hole, and the first elastic part is mounted in the mounting hole.

14. The battery pack according to claim 13, characterized in that: At least one of the side walls of the first groove and the side walls of the second groove is provided with a first matching structure, and the first elastic part is provided with a second matching structure, and the first matching structure and the second matching structure cooperate together to fix the first elastic part in the mounting hole.

15. The battery pack according to claim 14, characterized in that: The first matching structure and the second matching structure are both saw teeth, wherein the saw teeth of at least one of the second elastic part and the third elastic part mesh with the saw teeth of the first elastic part, or, The first matching structure is a fixing groove arranged in at least one of the side walls of the first groove and the side walls of the second groove, and the second matching structure is a fixing strip extending from the edge of the first elastic part, and the fixing strip is inserted into the fixing groove.

16. The battery pack according to any one of claims 1 to 15, characterized in that: The elastic member is foam.

17. An electrical equipment, characterized in that: It comprises a load and a battery pack as described in any one of claims 1 to 16, wherein the battery pack is used to supply power to the load.

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