Battery

Abstract

The present invention relates to the technical field of new energy, and discloses a battery, which comprises: a battery cell, which comprises a battery cell body and a tab part; a housing assembly; the pole is fixedly arranged on the shell assembly; one end of the adapter sheet is electrically connected with the pole, and the other end of the adapter sheet is electrically connected with the tab part; the tab part comprises a first tab region connected with the battery cell body and a second tab region far away from the battery cell body, and the first tab region and the second tab region are respectively positioned on two sides of the adapter plate along the first direction and are connected through a bending region; in the first direction, the distance between the surface of one side, close to the battery cell body, of the adapter plate and the lug root part, connected with the battery cell body, of the first lug region is a, the thickness of the lug part is m, and m / a is larger than or equal to 0.1 and smaller than or equal to 0.95. According to the battery provided by the invention, the tab part is prevented from being inversely inserted into the battery cell body, and the overcurrent capability and the space utilization rate of the battery are ensured.

Description

Technical Field

[0001] The present invention relates to the field of new energy technology, and in particular to a battery. Background Art

[0002] In the related art, the tabs are often stacked and gathered at the bottom of the adapter.

[0003] By improving the tab layout and placing some tabs above the adapter, the overall space utilization inside the battery can be improved. However, this improved arrangement makes it easy for the tabs to be inserted upside down, which can lead to overlapping of the positive and negative poles of the battery cell and cause an internal short circuit. Summary of the Invention

[0004] In view of this, the present invention provides a battery to solve the problem that the tab is easily inserted upside down, resulting in an internal short circuit in the battery.

[0005] The present invention provides a battery, comprising:

[0006] A battery cell, the battery cell comprising a battery cell body and a tab portion, the tab portion extending from a first end surface of the battery cell body along a first direction, the first direction being perpendicular to the first end surface of the battery cell, the tab portion being electrically connected to the battery cell body;

[0007] The housing assembly is formed with a receiving space, and the battery cell is arranged in the receiving space;

[0008] A pole, fixedly arranged on the housing assembly;

[0009] An adapter, one end of which is electrically connected to the pole, and the other end of which is electrically connected to the pole ear;

[0010] The tab portion includes a first tab region connected to the cell body and a second tab region away from the cell body, the first tab region and the second tab region are respectively located on both sides of the adapter along the first direction, and the first tab region and the second tab region are connected via a bending region;

[0011] Along the first direction, the distance between the surface of the adapter close to the battery body and the base of the first tab area connected to the battery body is a, and the thickness of the tab is m, satisfying: 0.1≤m / a≤0.95.

[0012] Beneficial effect: By controlling the lower limit value of m / a, m / a can be prevented from being too small. When m / a is too small, the loose tabs between the adapter and the battery body are too dense, and are easily inserted into the battery body, causing the tabs to pierce the diaphragm and overlap with the pole pieces with opposite charges, thereby causing a short circuit inside the battery; and by controlling the upper limit value of m / a, m / a can be prevented from being too large. When m / a is too large, the battery's space utilization rate is poor, the energy density is low, and the tab overcurrent capacity is low. The current transmission path inside the battery is long, which easily leads to poor overcurrent capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0014] Figure 1 is a schematic diagram of a battery of the present invention;

[0015] Figure 2 Schematic diagram of the decomposed state of the battery of the present invention;

[0016] Figure 3 A top view of the battery of the present invention;

[0017] Figure 4 for Figure 3 Schematic diagram of the middle BB section;

[0018] Figure 5 Schematic diagram of an exploded view of a battery of the present invention from a cross-sectional perspective;

[0019] Figure 6 This is a physical picture of the battery of the present invention from a cross-sectional perspective;

[0020] Figure 7 Schematic diagram of the interior of the battery cell of the present invention.

[0021] Description of reference numerals:

[0022] 1. Shell; 2. Cover; 21. Plate body; 22. Post; 3. Cell; 31. Cell body; 32. Tab; 321. First tab area; 322. Bend area; 323. Second tab area; 324. Tab root; 4. Adapter;

[0023] 301, diaphragm; 302, first pole piece; 303, second pole piece. DETAILED DESCRIPTION

[0024] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0025] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0027] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] In related technologies, the tabs are often stacked and gathered at the bottom of the adapter. When the tabs are welded to the adapter, the tabs are welded to the bottom surface of the adapter, resulting in a large height space required between the adapter and the battery cell, resulting in low battery space utilization and affecting battery energy density. Figure 6 As shown, since the tab is usually led out from one end of the battery body and a large number of tab sheets are stacked and pressed to form an overall structure, in order to further improve the space utilization in the height direction of the battery, the tab sheet that has not been fully pressed can be placed under the adapter, and the tab can be bent so that the bent tab covers the upper surface of the adapter, and the upper surface of the adapter is welded to the tab.

[0029] Research has found that this approach results in the adapter being too close to the cell body, causing the tabs between them to become loose and bulge beneath the adapter. During assembly or when the battery vibrates, the adapter can easily press against the tabs, leading to inverted insertion. This can cause the tabs to become inserted into the cell, causing the separator to pull the positive and negative electrodes out, or the tabs to pierce the separator, causing the tabs to overlap with oppositely charged electrodes, potentially causing a short circuit within the battery.

[0030] The battery provided by the embodiments of the present invention can effectively prevent the tabs from being easily inserted upside down between the adapter and the battery body, thereby reducing the situation where the tabs pierce the diaphragm, avoiding the tabs from overlapping with pole pieces with opposite charges, and thus reducing the probability of internal short circuits in the battery.

[0031] The following combination Figures 1 to 7 , describing embodiments of the present invention.

[0032] According to an embodiment of the present invention, there is provided a battery comprising:

[0033] The battery cell 3 includes a battery cell body 31 and a tab portion 32. The tab portion 32 extends from a first end surface of the battery cell body 31 along a first direction. The first direction is perpendicular to the first end surface of the battery cell. The tab portion 32 is electrically connected to the battery cell body 31.

[0034] The housing assembly is formed with a receiving space, and the battery cell 3 is arranged in the receiving space;

[0035] The pole 22 is fixed to the housing assembly;

[0036] The adapter plate 4 has one end electrically connected to the pole 22 and the other end electrically connected to the pole ear 32;

[0037] The tab portion 32 includes a first tab region 321 connected to the cell body 31 and a second tab region 323 away from the cell body 31 . The first tab region 321 and the second tab region 323 are respectively located on both sides of the adapter plate 4 along the first direction, and the first tab region 321 and the second tab region 323 are connected via a bending region 322 .

[0038] Along the first direction, the distance between the surface of the adapter plate 4 close to the battery cell body 31 and the electrode ear root 324 of the first electrode ear region 321 connected to the battery cell body 31 is a, and the thickness of the electrode ear portion 32 is m, satisfying: 0.1≤m / a≤0.95.

[0039] In this embodiment, the battery cell serves as the smallest charging and discharging unit of the battery. The battery cell includes a battery cell body 31 and a pole ear portion 32. The battery cell body 31 includes a positive electrode sheet, a negative electrode sheet and a separator arranged therebetween. The positive electrode sheet, the negative electrode sheet and the separator are wound or stacked to form the battery cell body 31. The pole ear portion 32 extends from the first end face of the battery cell body 31 along the first direction.

[0040] The pole ear portion 32 serves as the current output end of the battery cell, and the pole ear portion is connected to the positive electrode sheet or the negative electrode sheet in an integral or separate manner.

[0041] The positive electrode sheet includes a positive electrode current collector and a positive electrode active material. The positive electrode current collector can be made of metal materials such as aluminum foil, nickel foil, stainless steel, or a composite foil formed by a combination of metal and insulating materials. The positive electrode active material includes a positive electrode active main material, a conductive agent, an adhesive, etc. The positive electrode active main material includes one or more lithium-containing positive electrode active materials such as lithium iron phosphate, a ternary material containing nickel, cobalt and manganese, and lithium iron manganese phosphate;

[0042] Similarly, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material. The negative electrode current collector can be made of metal materials such as copper foil, aluminum foil, stainless steel, or a composite foil formed by a combination of metal and insulating materials; the negative electrode active material includes a negative electrode active main material, a conductive agent, an adhesive, etc. The negative electrode active main material includes one or more negative electrode active main materials such as artificial graphite, natural graphite, silicon carbon, silicon oxide, lithium titanate, etc.

[0043] Combine Figure 1 、 Figure 2 As shown, the battery of this embodiment includes a housing assembly, which forms a housing space for accommodating the battery cell 3. The housing assembly may specifically include a housing 1 and a cover plate 2. The housing 1 is formed with an opening, and the cover plate 2 is provided to cover the opening of the housing 1.

[0044] The pole 22 is fixedly arranged on the shell assembly. In this embodiment, the cover plate 2 includes a plate body 21 and a pole 22 arranged on the plate body 21. The plate body 21 and the pole 22 are insulated. The pole 22 is used to connect the battery cell 3 with the external circuit to ensure stable current transmission. In the specific connection process, the pole ear 32 extends from at least one end of the battery cell body 31 along the first direction, and the pole 22 is connected to the pole ear 32 through the adapter 4.

[0045] The adapter plate 4 and the pole lug 32 can be electrically connected by welding. Similarly, the adapter plate 4 and the pole 22 can also be electrically connected by welding. Welding includes ultrasonic welding, resistance welding, laser welding and other methods.

[0046] In this embodiment, the material of the housing assembly may include metal materials such as aluminum, aluminum alloy, copper, nickel, stainless steel, and carbon steel.

[0047] Combine Figure 4 As shown, the pole ear portion 32 of this embodiment includes a first pole ear area 321 connected to the battery cell body 31 and a second pole ear area 323 away from the battery cell body 31, the first pole ear area 321 and the second pole ear area 323 are respectively located on both sides of the adapter plate 4 along the first direction, and the first pole ear area 321 and the second pole ear area 323 are connected via the bending area 322; by welding the upper surface of the adapter plate 4 to the first pole ear area 321, a stable connection between the pole ear portion 32 and the adapter plate 4 is achieved.

[0048] And further combined Figure 6As shown, the pole ear portion 32 located between the adapter plate 4 and the battery cell body 31 is in a loose state and bulges below the adapter plate 4. Therefore, the pole ear portion 32 in a loose state is located in the area between the surface of the adapter plate 4 along the first direction close to the battery cell body 31 and the surface of the battery cell body 31 along the first direction close to the adapter plate 4. The size needs to be reasonably controlled to avoid the phenomenon of inverted insertion of this part of the pole ear located between the adapter plate and the battery cell body.

[0049] The thickness m of the tab portion 32 actually represents the thickness of the overall structure formed by stacking and pressing the tab sheets together. This thickness directly affects the number of tab sheets contained in the tab. When the number of tab sheets is large, if the dimension a remains unchanged, a larger number of loose tab sheets must be accommodated within the same space, making the tab portion 32 more susceptible to inverted insertion, affecting the overall performance and safety of the battery. Conversely, when the number of tab sheets is small, the loose tab portion 32 occupies less space, reducing the risk of inverted insertion, but the current carrying capacity of the tab portion 32 is weakened.

[0050] The distance between the surface of the adapter plate 4 close to the battery cell body 31 and the electrode ear root 324 of the first electrode ear region 321 connected to the battery cell body 31 is a, wherein the electrode ear root 324 is the edge of the electrode active material coating area.

[0051] This embodiment controls the lower limit value of m / a to prevent m / a from being too small. When m / a is too small, the loose ear portion 32 between the adapter 4 and the battery body 31 is too dense and easily inserted into the battery body 31, causing the ear portion 32 to pierce the diaphragm 301 and overlap with the electrode with opposite charge, thereby causing a short circuit inside the battery; and controls the upper limit value of m / a to prevent m / a from being too large. When m / a is too large, the space utilization rate of the battery is poor, the energy density is low, and the number of ear pieces contained in the ear portion 32 is small, which easily leads to poor overcurrent capacity.

[0052] In some embodiments, the following is satisfied: 1 mm ≤ a ≤ 5 mm.

[0053] When a is too small, the space between the adapter plate 4 and the battery body 31 for accommodating the loose tabs 32 is small, which easily makes the tabs 32 too dense, thereby increasing the risk of reverse insertion and making it easy for the tabs to pierce the diaphragm, causing an internal short circuit in the battery. When a is too large, the space between the adapter plate 4 and the battery body 31 for accommodating the loose tabs 32 is large. Although the tabs 32 can be more loosely distributed in the space, reducing the risk of reverse insertion, the excessive space makes the battery structure loose, resulting in poor space utilization of the battery, affecting the overall compactness and energy density, and is not conducive to the efficient use of the battery. Moreover, when a is too large, the length of the tab from the battery body 31 to the adapter plate 4 is too long, resulting in an increased overcurrent path, making the internal resistance of this part larger, affecting the current transmission efficiency, and easily generating excessive heat, further reducing the safety performance of the battery.

[0054] Illustratively, in this embodiment, the value of a can be 1 mm or 1.5 mm or 2 mm or 2.8 mm or 3 mm or 3.6 mm or 4 mm or 4.5 mm or 5 mm, etc., or can be an interval range formed by any two of the above values.

[0055] In some embodiments, the following is satisfied: 0.2 mm ≤ m ≤ 2 mm.

[0056] When m is too small, the number of single tabs is small, the tab portion 32 is too thin, and the current carrying capacity is weak, resulting in poor current carrying capacity of the tab portion 32; when m is too large, the number of single tabs is large, and the thickness of the tab portion 32 increases. Although the current carrying capacity is enhanced, the excessively thick tab portion 32 occupies more space, increasing the risk of inverted insertion, and it is easy for the tab to pierce the diaphragm, causing an internal short circuit in the battery.

[0057] Illustratively, in this embodiment, the value of m may be 0.2 mm, 0.7 mm, 1 mm, 1.2 mm, 1.5 mm, 1.7 mm, or 2 mm, etc., or may be an interval formed by any two of the above values.

[0058] This embodiment effectively balances the current carrying capacity of the lug portion 32 and the risk of inverted insertion by reasonably controlling the value range of m and a, ensuring a balance between high energy density and safety of the battery, thereby improving the overall performance and service life of the battery.

[0059] In some embodiments, combined Figure 7 As shown, the cell body 31 includes a first pole piece 302 and a second pole piece 303 that are stacked, and a diaphragm 301 is provided between the first pole piece 302 and the second pole piece 303. The diaphragm 301 is made of an insulating material.

[0060] At least one of the first pole piece 302 and the second pole piece 303 extends along the first direction to form a pole ear portion 32;

[0061] The diaphragm 301 is disposed beyond the first pole piece 302 and / or the second pole piece 303 .

[0062] The diaphragm 301 at least includes a base film, and the base film can be made of materials such as PP or PE;

[0063] It may also include a ceramic layer and a glue layer, wherein the ceramic layer is formed by a composite of boehmite and PVDF.

[0064] In some embodiments, the surface with the largest area among the external surfaces of the battery cell body 31 is defined as the large surface. In the direction perpendicular to the large surface of the battery cell body 31, the projected area of ​​the diaphragm 301 on the large surface is s1, and the projected area of ​​the first electrode 302 or the second electrode 303 on the large surface is s2, satisfying: 1.01<s1 / s2≤1.5.

[0065] The first electrode 302 and the second electrode 303 can be the positive electrode and the negative electrode respectively, or the first electrode 302 and the second electrode 303 can be the negative electrode and the positive electrode respectively. The diaphragm 301 is arranged between the first electrode 302 and the second electrode 303 to play an insulating role and prevent the electrodes from short-circuiting.

[0066] At the same time, since one of the first pole piece 302 and the second pole piece 303 extends along the first direction to form a pole ear portion 32, in order to avoid the pole ear portion 32 from contacting the pole piece with opposite charge during the extension process, it is necessary to ensure that the diaphragm 301 covers a sufficient area to effectively isolate the pole ear portion 32 from the adjacent pole piece to prevent short circuit caused by contact.

[0067] This embodiment controls the ratio of s1 / s2 to ensure that the diaphragm 301 covers a sufficient area, ensures the internal insulation of the battery cell body 31 by the diaphragm 301, reduces the risk caused by inverted insertion of the pole ear, effectively isolates the pole ear portion 32 from the pole piece with opposite charge, reduces the risk of short circuit, and further improves the safety and stability of the battery.

[0068] Illustratively, in this embodiment, the value of s1 / s2 may be 1.01 or 1.08 or 1.12 or 1.18 or 1.21 or 1.26 or 1.35 or 1.38 or 1.42 or 1.5, etc., or may be an interval range formed by any two of the above values.

[0069] In some embodiments, as a further preference, the following is satisfied: 0.2≤m / a≤0.95.

[0070] By increasing the lower limit of m / a, the thickness m of the pole lug portion 32 is made relatively thicker, thereby improving the overall current carrying capacity of the pole lug portion 32 .

[0071] In some embodiments, an insulating layer is provided on the first electrode 302, and the insulating layer is provided on at least one surface of the first current collector. One end of the insulating layer is connected to the end of the electrode active material, and the other end is spaced apart from the end of the electrode ear 32, satisfying: 0.25≤m / a≤0.95.

[0072] In some embodiments, the cell body 31 includes a first pole piece 302 and a second pole piece 303 that are stacked, and a diaphragm 301 is provided between the first pole piece 302 and the second pole piece 303. The diaphragm 301 is made of insulating material. The thickness of the diaphragm 301 is h, satisfying: 5μm≤h≤30μm.

[0073] This embodiment controls the lower limit of the thickness h of the diaphragm 301 to avoid the risk of the ear portion 32 easily piercing the diaphragm and causing a short circuit when being inserted upside down due to h being too thin; at the same time, by controlling the upper limit of the thickness h of the diaphragm 301, the diaphragm is prevented from occupying a large space in the battery cell 3, thereby avoiding affecting the volume and energy density of the battery cell body 31, ensuring that the diaphragm 301 does not increase the overall size of the battery while providing effective insulation, thereby optimizing battery performance.

[0074] Illustratively, in this embodiment, the value of h can be 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 18 μm, 22 μm, 25 μm, 29 μm, or 30 μm, etc., or can be an interval formed by any two of the above values.

[0075] In some embodiments, the following is further satisfied: 0.3≤m / a≤0.95.

[0076] By controlling the lower limit of the thickness h of the diaphragm 301, the risk of the tab 32 easily piercing the diaphragm and causing a short circuit when the tab is inserted upside down due to h being too thin is avoided. That is, the tab is not easy to pierce the diaphragm when inserted upside down. Therefore, the lower limit of the ratio m / a is appropriately increased, which can further improve the tab's current capacity and the space utilization rate of the battery.

[0077] In some embodiments, the Brinell hardness of the tab portion 32 is k, which satisfies the following: 20≤k≤120.

[0078] When the Brinell hardness k of the tab 32 is too small, the tab 32 is relatively soft. Although it is less likely to puncture the diaphragm when the tab 32 is inserted upside down, an excessively small Brinell hardness k may cause the tab 32 to deform during assembly and easily tear, affecting the flow rate. When the Brinell hardness k of the tab 32 is too large, the tab 32 is relatively hard. When the tab 32 is inserted upside down, it is more likely to puncture the diaphragm 301. However, the higher hardness makes the tab 32 less likely to tear. Therefore, reasonably controlling the Brinell hardness k of the tab 32 within an appropriate range can prevent puncture of the diaphragm when inserted upside down and ensure that it maintains a stable shape during assembly and use, thereby optimizing the overall performance and safety of the battery.

[0079] Illustratively, in this embodiment, the value of k may be 20, 30, 45, 55, 72, 83, 120, etc., or may be an interval formed by any two of the above values.

[0080] In some embodiments, the material of the tab portion 32 is aluminum, satisfying the following relationship: 0.3≤m / a≤0.95.

[0081] In this embodiment, the positive electrode tab is generally made of aluminum. Since aluminum is relatively hard, it is easier to puncture the diaphragm when inserted upside down. Therefore, the upper limit of m / a needs to be limited to prevent the tab portion 32 from puncturing the diaphragm.

[0082] In some embodiments, the material of the tab portion 32 is copper, which satisfies the following condition: 0.1≤m / a≤0.7.

[0083] In this embodiment, the negative electrode tab is generally made of copper. Since copper is relatively soft, it is not easy to pierce the diaphragm when inserted upside down. Therefore, the lower limit of m / a can be appropriately increased to further ensure the flow capacity of the tab portion 32.

[0084] In some embodiments, the battery further includes a housing 1, wherein the battery cell 3 is disposed within the housing 1; the housing 1 includes a first housing wall 11, and the adapter plate 4 and the first housing wall 11 are respectively located on both sides of the bending region 322 along the second direction;

[0085] Along the second direction, the minimum distance between the adapter plate 4 and the first shell wall 11 is b, which satisfies: 2 mm ≤ b ≤ 8 mm.

[0086] Combine Figure 4 、 Figure 6As shown, the tabs located in the bend area 322 are prone to arching, making the tab insertion more likely. This embodiment controls the lower limit of the minimum spacing b between the adapter plate 4 and the first shell wall 11 to prevent b from being too small. When b is too small, the adapter plate 4 and the first shell wall 11 are too close, leaving less space for the tab to pass through, and the tab portion 32 is prone to tearing. The embodiment also controls the upper limit of the minimum spacing b between the adapter plate 4 and the first shell wall 11 to prevent b from being too large. When b is too large, the spacing between the adapter plate 4 and the first shell wall 11 is too large, and the tab portion 32 is prone to arching too high toward the battery cell body 31, making the tab insertion more likely.

[0087] By properly adjusting the spacing b, it is ensured that the tab portion 32 is neither easily torn nor easily arched or inserted upside down during assembly and use, thereby effectively improving the safety and stability of the battery.

[0088] In some embodiments, the cell body 31 includes pole pieces, which include a first pole piece 302 and a second pole piece 303 ;

[0089] The flattened surface of the pole ear portion 32 includes a second direction perpendicular to the first direction. Along the second direction, the size of the pole ear portion 32 is smaller than the size of the pole piece.

[0090] By making the size of the pole ear 32 smaller than the size of the pole piece, the risk of the pole ear 32 being inserted into the battery cell upside down is reduced after the size of the pole ear 32 is reduced, thereby avoiding the diaphragm from leaking the positive and negative pole pieces, and further avoiding the overlap of the positive and negative pole pieces, thereby preventing the risk of internal short circuit in the battery.

[0091] In some embodiments, the first tab region 321 and the second tab region 323 are disposed on the same side of the battery cell 3 , satisfying the following relationship: 0.2≤m / a≤0.8.

[0092] During the overall assembly of the pole ear 32 and the adapter plate 4 or when the battery is vibrated, the adapter plate 4 presses against the pole ear 32, which easily causes the pole ear 32 to be inserted into the battery cell 3. Therefore, by controlling m / a to be within the above-mentioned range, on the one hand, the risk of internal short circuit of the battery caused by the upside-down insertion of the pole ear 32 can be avoided. On the other hand, when the first pole ear area 321 and the second pole ear area 323 are arranged on the same side of the battery cell 3, the problem of limited current transmission can be avoided, thereby improving the overall overcurrent capacity of the pole ear 32.

[0093] In some embodiments, the battery includes at least two battery cells 3, and the at least two battery cells 3 include a first battery cell and a second battery cell;

[0094] The tab portion 32 of the first battery cell and the tab portion 32 of the second battery cell are respectively bent from two opposite sides of the adapter plate 4 and are both disposed on a surface of the adapter plate 4 facing away from the battery cell 3 .

[0095] By bending the pole ears 32 of the two battery cells from opposite sides of the adapter plate 4, the overall thickness of the pole ears 32 can be reduced, avoiding the pole ears 32 located at the bottom of the adapter plate 4 from bulging too high, which makes it easy for the pole ears 32 to be inserted into the battery cell.

[0096] In this embodiment, the battery can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel metal hydride battery, a nickel cadmium battery, a lead storage battery, etc., but this embodiment is not limited to this.

[0097] A battery typically includes a housing 1, a cell 3, a transfer plate 4, and an electrolyte. The housing 1 is used to house the cell 3 and the electrolyte. The housing 1 generally includes a housing body and a cover plate 2. At least one positive electrode post and at least one negative electrode post are disposed on the housing body and / or the cover plate. The cell 3 includes one or more electrode assemblies, each formed by stacking or winding positive and negative electrode sheets, and a separator. The separator is located between adjacent positive and negative electrode sheets to insulate the positive and negative electrode sheets. At least one end of the electrode assembly has a tab 32 extending therefrom. One end of the transfer plate 4 is electrically connected to the tab 32, and the other end is electrically connected to the post 22.

[0098] The battery provided in this embodiment has a specific preparation process as follows: the positive electrode sheet, the negative electrode sheet and the diaphragm are wound to form an electrode assembly, and the pole ear portion 32 is led out at one end of the electrode assembly. When the pole ear portion 32 is fixed to the adapter 4, the electrode assembly and the pole ear portion 32 are first placed along the lead-out direction of the pole ear portion 32, and then the pole ear portion 32 of the electrode assembly is welded to the pole ear welding area of ​​the adapter 4, and then the adapter 4 is welded to the pole column 22 on the cover plate and the pole column welding area of ​​the adapter 4. After welding, the pole column 22 and the pole ear portion 32 are located on the same side of the thickness direction of the adapter 4, and then the electrode assembly is folded along the connection position between the pole ear portion 32 and the electrode assembly so that the electrode assembly and the pole column 22 are located on both sides of the thickness direction of the adapter 4, the folded electrode assembly is put into the shell, and the cover plate 2 is welded and sealed to the shell body, liquid is injected, chemically formed, and the liquid injection hole is sealed to obtain a battery.

[0099] In conjunction with Table 1 below, through several examples and comparative examples, the provided batteries were subjected to a cell short circuit test and a battery overcurrent capacity test to verify whether they were qualified.

[0100] Table 1

[0101]

[0102]

[0103] Regarding the above table, the following are explained:

[0104] Battery short circuit test method: For each embodiment and comparative example, 10 batteries were taken respectively; the battery was discharged to 0% SOC at 0.33C, and after standing for 10 minutes, the battery was charged to 100% SOC at 0.33C, and after standing for 5 minutes, the voltage at this time was recorded as U1. After the battery was stood at a temperature of 25°C for 12 hours, the battery voltage was measured and recorded as U2. According to the formula: voltage change rate = (U1-U2) / U1×100%, the voltage change rate was calculated. The voltage change rates of 10 batteries were tested separately, and the average value was taken. If the voltage change rate is greater than or equal to 0.8%, the battery has an internal short circuit, that is, it is unqualified. If the voltage change rate is less than 0.8%, the battery has an internal short circuit, that is, it is unqualified.

[0105] Battery overcurrent capacity test method: For each embodiment and comparative example, 10 batteries were taken; the battery was discharged to 0% SOC at 0.33C, and after standing for 60 minutes, the temperature at this time was measured and recorded as t1. The battery was charged to 100% SOC at 1C, and the time was recorded as T. The temperature at this time was measured and recorded as t2. The temperature rise rate was calculated according to the formula: temperature rise rate = (t2-t1) / T. If the temperature rise rate is greater than or equal to 0.9℃ / min, it is unqualified; if the temperature rise rate is less than 0.9℃ / min, it is qualified.

[0106] Regarding the test results, combined with Table 1 above, the following is explained:

[0107] From the comparison of the experimental data of Examples 1 to 20 with Comparative Examples 1 to 4, it can be concluded that: when m and a satisfy the relationship, the temperature rise of the battery during charging is small and has good overcurrent capacity; and the voltage drop rate is small when the battery is placed, and the risk of internal short circuit is small; from the comparison of the experimental data of Examples 1 to 16 with Examples 17 to 20, it can be found that when m is too small, although the formula is satisfied and there is still a good effect, m is too small, which will lead to poor strength of the tab, insufficient strength, and easy tearing during vibration; when m is too large, although the formula is satisfied and there is still a good effect, m is too large, which will lead to the foil thickness in the battery being too thick, thereby reducing the energy density of the battery; when a is too small, although the formula is satisfied and there is also a good effect, a too small a will easily damage the battery cell during the battery assembly process; when a is too large, although the formula is satisfied and there is also a good effect, a too large a will easily occupy too much space inside the battery, affecting the energy density of the battery.

[0108] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the present invention.

Claims

1. A battery, characterized in that: include: A battery cell (3), the battery cell (3) comprising a battery cell body (31) and a pole ear portion (32), the pole ear portion (32) extending from a first end surface of the battery cell body (31) along a first direction, the first direction being perpendicular to the first end surface of the battery cell, the pole ear portion (32) being electrically connected to the battery cell body (31); A housing assembly is formed with a receiving space, and the battery core (3) is arranged in the receiving space; A pole (22) fixedly mounted on the housing assembly; A switching piece (4), one end of which is electrically connected to the pole (22), and the other end of which is electrically connected to the pole ear (32); The pole ear portion (32) comprises a first pole ear region (321) connected to the battery cell body (31) and a second pole ear region (323) away from the battery cell body (31), the first pole ear region (321) and the second pole ear region (323) being respectively located on both sides of the adapter plate (4) along the first direction, and the first pole ear region (321) and the second pole ear region (323) being connected via a bending region (322); Along the first direction, the distance between the surface of the adapter plate (4) close to the battery cell body (31) and the pole ear root (324) of the first pole ear region (321) connected to the battery cell body (31) is a, and the thickness of the pole ear portion (32) is m, satisfying: 0.1≤m / a≤0.

95.

2. The battery according to claim 1, characterized in that The battery cell body (31) comprises a first pole piece (302) and a second pole piece (303) which are stacked, a diaphragm (301) is provided between the first pole piece (302) and the second pole piece (303), and the diaphragm (301) is made of an insulating material; At least one of the first pole piece (302) and the second pole piece (303) extends along the first direction to form the pole ear portion (32); The diaphragm (301) is arranged beyond the first pole piece (302) and / or the second pole piece (303).

3. The battery according to claim 2, characterized in that The surface with the largest area among the outer surfaces of the battery cell body (31) is defined as a large surface. In a direction perpendicular to the large surface of the battery cell body (31), the projected area of ​​the diaphragm (301) on the large surface is s1, and the projected area of ​​the first pole piece (302) or the second pole piece (303) on the large surface is s2, satisfying the following: 1.01<s1 / s2≤1.

5.

4. The battery according to claim 3, characterized in that Satisfies: 0.2≤m / a≤0.

95.

5. The battery according to claim 2, characterized in that An insulating layer is provided on the first pole piece (302), and the insulating layer is provided on at least one surface of the first current collector. One end of the insulating layer is connected to the end of the pole piece active material, and the other end is spaced apart from the end of the pole ear (32), satisfying the following conditions: 0.25≤m / a≤0.

95.

6. The battery according to claim 1, characterized in that The battery cell body (31) comprises a first pole piece (302) and a second pole piece (303) which are stacked, a diaphragm (301) is provided between the first pole piece (302) and the second pole piece (303), and the diaphragm (301) is made of an insulating material; the thickness of the diaphragm (301) is h, which satisfies the following conditions: 5 μm≤h≤30 μm.

7. The battery according to claim 6, characterized in that Satisfies: 0.3≤m / a≤0.

95.

8. The battery according to claim 1, characterized in that The Brinell hardness of the pole lug portion (32) is k, which satisfies: 20≤k≤120.

9. The battery according to claim 8, characterized in that The material of the pole ear portion (32) is aluminum, which satisfies the following conditions: 0.3≤m / a≤0.

95.

10. The battery according to claim 8, characterized in that The material of the pole ear portion (32) is copper, which satisfies the following conditions: 0.1≤m / a≤0.

7.

11. The battery according to any one of claims 1 to 10, characterized in that The battery further comprises a shell (1), the battery cell (3) being arranged in the shell (1); the shell (1) comprises a first shell wall (11), the adapter plate (4) and the first shell wall (11) being respectively located on both sides of the bending area (322) along the second direction; Along the second direction, the minimum distance between the adapter plate (4) and the first shell wall (11) is b, which satisfies: 2mm≤b≤8mm.

12. The battery according to claim 1, characterized in that Satisfies: 1mm≤a≤5mm.

13. The battery according to claim 1, characterized in that Satisfies: 0.2mm≤m≤2mm.

14. The battery according to any one of claims 1 to 10, characterized in that The battery cell body (31) includes pole pieces, and the pole pieces include a first pole piece (302) and a second pole piece (303); The flattened surface of the pole ear portion (32) includes a second direction perpendicular to the first direction, and along the second direction, the size of the pole ear portion (32) is smaller than the size of the pole piece.

15. The battery according to claim 14, characterized in that The first tab region (321) and the second tab region (323) are arranged on the same side of the battery cell (3), satisfying the following relationship: 0.2≤m / a≤0.

8.

16. The battery according to claim 14, characterized in that The battery comprises at least two battery cells (3) therein, and the at least two battery cells (3) comprise a first battery cell and a second battery cell; The pole ear portion (32) of the first battery cell and the pole ear portion (32) of the second battery cell are respectively bent from two opposite sides of the adapter plate (4) and are both arranged on the surface of the adapter plate (4) facing away from the battery cell (3).

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