Battery, battery pack and electric equipment

Abstract

The invention discloses a battery, a battery pack and electric equipment, the battery comprises a shell, an adapter plate and a battery cell, the shell is provided with a pole, the adapter plate is arranged in the shell and is electrically connected with the pole, the battery cell is arranged in the shell, the battery cell comprises a battery cell body and a tab, the tab is electrically connected with the battery cell body, and the tab is electrically connected with the battery cell body. The tab extends out of the battery cell body, one end, far away from the battery cell body, of the tab is bent along the first direction of the shell and then is connected to one side, back to the battery cell, of the adapter plate, and a bent part is formed at the bent part of the tab; wherein the distance between the two inner side walls of the shell in the first direction is Dmm, the size of the switching piece in the first direction of the shell is dmm, the thickness of the tab is Ymm, and (D-d) / Y is larger than or equal to 3 and smaller than or equal to 150. According to the invention, rubbing between the tabs and the shell can be avoided, short circuit of the battery is avoided, and better over-current performance of the battery is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery, a battery pack, and an electrical device. Background Art

[0002] At present, a lithium-ion battery includes a housing, a cover plate, an electrode core, and a connecting piece. The cover plate is disposed on the housing, and a pole column is provided on the cover plate. The connecting piece and the electrode core are both located inside the housing, and the connecting piece is connected to the pole column. One side of the electrode core is provided with a tab, and the tab is electrically connected to the surface of the connecting piece after being bent.

[0003] However, the bent part of the tab will protrude outwards, so when the electrode core is placed in the housing, the bent part of the tab is likely to rub against the housing, easily causing a short circuit of the battery and the tab is easily scratched. Summary of the Invention

[0004] The primary object of the present invention is to provide a battery to avoid the tab from rubbing against the outer shell and avoid short-circuiting of the battery.

[0005] Another object of the present invention is to provide a battery pack using the above battery.

[0006] Other objects of the present invention are to provide an electrical device using the above battery pack.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: A battery having a first direction, a second direction, and a third direction that are perpendicular to each other and intersecting, includes: An outer shell provided with a pole column on the outer shell; A connecting piece disposed inside the outer shell and electrically connected to the pole column; An electrode core disposed inside the outer shell, the electrode core including an electrode core body and a tab, the tab extending from the electrode core body, and one end of the tab away from the electrode core body being bent along the first direction of the outer shell and connected to the side of the connecting piece facing away from the electrode core, and a bent portion being formed at the bent portion of the tab; Wherein, the distance between two inner side walls of the outer shell in the first direction is D mm, the size of the connecting piece in the first direction of the outer shell is d mm, the thickness of the tab is Y mm, and 3 ≤ (D - d) / Y ≤ 150.

[0008] The present invention also relates to a battery pack including the battery.

[0009] The present invention also relates to an electrical device including the battery pack.

[0010] Compared with the prior art, the beneficial effects of a battery according to an embodiment of the present invention are as follows: In the present invention, when the pole ear is connected to the adapter, the pole ear needs to be bent along the first direction of the shell and then welded to the adapter. At this time, the pole ear protrudes at the position where the bending is performed and forms the bent portion. Taking into account the distance D between the two inner walls of the shell in the first direction, the dimension d of the adapter in the first direction of the shell, and the thickness Y of the pole ear, 3≤(Dd) / Y≤150 is maintained, which can avoid the pole ear and the shell from being scratched when the battery cell is put into the shell, causing a battery short circuit, and also avoid insufficient battery overcurrent capacity, increased battery heat generation, and increased temperature rise. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a three-dimensional diagram of the overall structure of an embodiment of the present invention; Figure 2 is an exploded view of the overall structure of an embodiment of the present invention; Figure 3 is a schematic diagram of a battery cell and a switching sheet according to an embodiment of the present invention; Figure 4 yes Figure 3 A in the enlarged view; Figure 5 is a schematic diagram of a tab of one embodiment of the present invention; Figure 6 is a schematic diagram of a tab of another embodiment of the present invention; Figure 7 is a schematic diagram of a tab of another embodiment of the present invention; Figure 8 Schematic diagram of a tab and a transfer sheet according to an embodiment of the present invention.

[0012] In the figure, 1. Shell; 11. Pole; 12. Shell; 13. Cover plate; 14. Arc-shaped portion; 2. adapter plate; 21. first connecting portion; 22. second connecting portion; 3. Battery cell; 31. Battery cell body; 32. Tab; 321. Bending portion; 322. First welding area; 323. Second welding area; 324. Sub-tab; 325. Folding portion; 4. Insulation layer. DETAILED DESCRIPTION

[0013] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0014] In the description of the present invention, it should be understood that the term "comprising" used in the specification of the present invention means the presence of the described features, integers, steps, operations, components and / or assemblies, but does not exclude the presence or addition of one or more other features, integers, steps, operations, components, assemblies and / or their groups. It should be understood that when we say a component is "connected" to another component, it can be directly connected to other components, or there may also be intermediate components. The phrase "and / or" used herein includes all or any unit and all combinations of one or more of the associated listed items.

[0015] As Figures 1 to 8 shown, the present invention relates to a battery having a first direction, a second direction and a third direction that intersect perpendicularly to each other, and includes a housing 1, a connecting piece 2 and an electric core 3. A pole column 11 is provided on the housing 1. The connecting piece 2 is disposed inside the housing 1 and is electrically connected to the pole column 11. The electric core 3 is disposed inside the housing 1. The electric core 3 includes an electric core body 31 and a tab 32. The tab 32 extends from the electric core body 31. One end of the tab 32 away from the electric core body 31 is bent along the first direction of the housing 1 and then connected to the side of the connecting piece 2 facing away from the electric core 3, and a bent portion 321 is formed at the bent position of the tab 32. The first direction, the second direction and the third direction can be the width direction, the length direction and the height direction of the housing 1 respectively.

[0016] Wherein, the distance between the two inner side walls of the housing 1 in the first direction is D mm, the dimension of the connecting piece 2 in the first direction of the housing 1 is d mm, and the thickness of the tab 32 is Y mm, and 3 ≤ (D - d) / Y ≤ 150. The value of (D - d) / Y can be 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130 or 140.

[0017] In the present invention, when the tab 32 is connected to the connecting piece 2, the tab 32 needs to be bent along the first direction of the housing 1 and then welded to the connecting piece 2. At this time, the tab 32 protrudes at the position of the bending and forms the bent portion 321. By comprehensively considering the distance D between the two inner side walls of the housing 1 in the width direction, the dimension d of the connecting piece 2 in the width direction of the housing 1, and the thickness Y of the tab 32, and keeping 3 ≤ (D - d) / Y ≤ 150, it can be avoided that when the electric core 3 is put into the housing, the tab 32 rubs against the housing 1, causing a short circuit of the battery, and at the same time, it can also avoid insufficient over-current capacity of the battery, increased heat generation of the battery and increased temperature rise.

[0018] It should be noted that the outer shell 1, specifically, is disposed on the outermost side of the battery cell 3 and is used to protect the battery cell 3; the material of the outer shell 1 can be selected from, but not limited to, aluminum alloy, steel, etc.; specifically, it can be aluminum-manganese alloy, aluminum-magnesium alloy, stainless steel, nickel-plated steel, etc.

[0019] The adapter piece 2 is used to achieve current transmission and is electrically connected to the tab 32 and the terminal 11. The material of the adapter piece 2 can be aluminum, copper, etc.

[0020] The terminal 11 serves as the battery current output terminal and is used to connect to an external bus bar, etc., to achieve series and parallel connections between batteries; the terminal 11 can include a positive terminal and a negative terminal; the material of the terminal 11 can be aluminum, copper, copper-aluminum composite, etc. The tab 32 serves as the current output terminal inside the battery cell 3 and is used to be electrically connected to the terminal 11, etc. The tab 32 can be cut from a current collector or can be a separately formed metal piece. It can be understood that the positive tab is electrically connected to the positive electrode plate in the battery cell 3, and the negative tab is electrically connected to the negative electrode plate in the battery cell 3.

[0021] The battery cell 3 includes a positive electrode plate, a negative electrode plate, and a separator. The separator is disposed between the positive electrode plate and the negative electrode plate. The positive electrode plate, the negative electrode plate, and the separator are stacked to form the battery cell. The positive electrode plate includes a positive current collector and a positive active material layer, and the negative electrode plate includes a negative current collector and a negative active material layer. There is no particular limitation on the positive current collector as long as it has conductivity and does not cause adverse chemical changes in the battery. For example, stainless steel, aluminum, nickel, titanium, fired carbon, or aluminum or stainless steel surface-treated with one of carbon, nickel, titanium, silver, etc. can be used; the negative current collector can be made of copper, stainless steel, nickel, titanium, etc. In a specific embodiment, the positive electrode can be made of aluminum and the negative electrode can be made of copper. The positive active material layer includes a positive active material, and the positive active material includes nickel-cobalt-manganese ternary material, lithium iron phosphate material, lithium manganese iron phosphate material, etc.; the negative active material layer includes a negative active material, and the negative active material includes artificial graphite, natural graphite, silicon-based material, etc.

[0022] In some embodiments, 5 ≤ (D - d) / Y ≤ 125.

[0023] That is to say, by further controlling (D - d) / Y within the range of 5 - 125, the risk of the tab 32 rubbing against the outer shell 1 is further reduced, and the short-circuit risk of the battery is reduced. In addition, the over-current capacity of the battery is also improved.

[0024] In some embodiments, 5 mm ≤ D - d ≤ 30 mm and / or 0.05 mm ≤ Y ≤ 2.5 mm. Preferably, 8 mm ≤ D - d ≤ 25 mm. The value of D - d can be 9 mm, 12 mm, 15 mm, 20 mm, 23 mm, 25 mm, 28 mm or 29 mm. The value of Y can be 0.1 mm, 0.15 mm, 0.25 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm or 2.25 mm.

[0025] That is, by controlling the range of D - d within 5 - 30 mm, the tab 32 and the outer shell 1 are prevented from overlapping, so as to avoid short - circuit of the battery. D - d cannot be too small, otherwise the risk of abrasion between the bent portion 321 of the tab 32 and the outer shell 1 will increase, and the risk of battery short - circuit is high. D - d cannot be too large, otherwise the space utilization rate inside the outer shell 1 is relatively low.

[0026] Furthermore, 10 mm ≤ D ≤ 75 mm, 5 mm ≤ d ≤ 68 mm. The value of D can be 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm or 70 mm. The value of d can be 7 mm, 10 mm, 13 mm, 15 mm, 18 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 52 mm, 55 mm, 60 mm, 63 mm, 65 mm or 67 mm.

[0027] In some embodiments, the overlapping dimension of the tab 32 and the adapter piece 2 in the width direction of the outer shell 1 is L1 mm, where L1 ≥ d / 2 and 8 ≤ (D - d) / Y ≤ 100.

[0028] The overlapping dimension L1 of the tab 32 and the adapter piece 2 in the width direction of the outer shell 1 affects the over - current capacity of the battery. Therefore, the over - current performance of the battery is better when L1 ≥ d / 2. By controlling 8 ≤ (D - d) / Y ≤ 100, the risk of short - circuit between the tab 32 and the outer shell 1 is further reduced. At the same time, the insufficient over - current capacity of the battery is avoided, and in addition, the space utilization rate inside the outer shell 1 is improved.

[0029] In some embodiments, the overlapping dimension of the tab 32 and the adapter piece 2 in the width direction of the outer shell 1 is L1 mm, where d / 4 ≤ L1 < d / 2 and 8 ≤ (D - d) / Y ≤ 80.

[0030] When the overlapping dimension of the tab 32 and the adapter piece 2 is small, the overcurrent capacity of the battery is limited. By controlling 8 ≤ (D - d) / Y ≤ 80, it is avoided that the thickness of the tab 32 is too small, which affects the overcurrent capacity of the battery. At the same time, by controlling the dimension of D - d, it is also avoided that the thickness of the tab 32 is too large, which may cause rubbing between the tab 32 and the housing 1, reducing the risk of battery short - circuit.

[0031] In some embodiments, there is one battery cell 3. The overlapping dimension of the tab 32 and the adapter piece 2 in the width direction of the housing 1 is L1 mm, where 0.4 ≤ L1 / d ≤ 0.9 and 8 ≤ (D - d) / Y ≤ 125. The value of L1 can be 6 mm, 10 mm, 15 mm, 18 mm, 20 mm, 22 mm or 24 mm. The value of L1 / d can be 0.5, 0.6, 0.7 or 0.8.

[0032] When only one battery cell 3 is provided in the housing 1, further controlling (D - d) / Y within the range of 8 - 125 can balance the overcurrent capacity of the battery and avoid battery short - circuit.

[0033] In some embodiments, there are at least two battery cells 3 arranged along the width direction of the housing 1. The overlapping dimension of the tab 32 of a single battery cell 3 and the adapter piece 2 in the width direction of the housing 1 is L1 mm, where 0.2 ≤ L1 / d ≤ 0.45 and 25 ≤ (D - d) / Y ≤ 125.

[0034] When two or more battery cells 3 are provided in the housing 1, by controlling 0.2 ≤ L1 / d ≤ 0.45 and 25 ≤ (D - d) / Y ≤ 125, the overcurrent capacity of the battery and avoiding battery short - circuit can be balanced.

[0035] In some embodiments, the housing 1 includes a housing body 12 and a cover plate 13. In the height direction of the housing 1, at least one side of the housing body 12 has an opening, and the cover plate 13 is covered at the opening, and the terminal post 11 is arranged on the cover plate 13. The function of the cover plate 13 is to block the opening of the housing body 12. The material of the cover plate 13 can be the same as or different from that of the housing body 12. The material of the cover plate 13 can be aluminum alloy, stainless steel, nickel - plated steel, etc.

[0036] The adapter piece 2 and the battery cell body 31 are arranged opposite to and spaced apart from each other on the side surface in the length direction of the housing 1. The tab 32 extends from the side surface of the battery cell body 31 in the length direction of the housing 1 and is then connected to the adapter piece 2. In the height direction of the housing 1, the distance between one end of the tab 32 close to the cover plate 13 and the cover plate 13 is h1 mm, and the distance between one end of the adapter piece 2 close to the cover plate 13 and the cover plate 13 is h2 mm, where h2 < h1.

[0037] That is to say, the end of the adapter piece 2 close to the cover plate 13 protrudes from the end of the tab 32 close to the cover plate 13. Thus, after the tab 32 and the adapter piece 2 are welded, the size of the tab 32 that can be electrically connected to the adapter piece 2 subsequently becomes smaller, avoiding affecting the current-carrying capacity of the tab 32 again.

[0038] In some embodiments, 1 mm ≤ h1 - h2 ≤ 8 mm, and the value of h1 - h2 can be 2 mm, 3 mm, 4 mm, 5 mm, 6 mm or 7 mm.

[0039] Specifically, the difference between h1 and h2 cannot be too small, otherwise the edge of the tab 32 close to the cover plate 13 is too close to the edge of the adapter piece 2 close to the cover plate 13. When the tab 32 is welded, the heat generated by the welding is likely to affect other components of the battery, such as the insulating part between the cover plate 13 and the battery cell 3; the difference between h1 and h2 cannot be too large, otherwise the weldable size of the tab 32 and the adapter piece 2 will be reduced.

[0040] In some embodiments, the tab 32 extends from the side surface of the battery cell body 31 in the length direction of the housing 1. The size of the tab 32 in the height direction of the housing 1 is a mm, and the size of the battery cell body 31 in the height direction of the housing 1 is b mm, where 0.7 ≤ a / b ≤ 1. The value of a / b can be 0.75, 0.8, 0.85, 0.9 or 0.95.

[0041] a / b is the ratio of the size of the tab 32 in the height direction of the housing 1 to the size of the battery cell body 31 in the height direction of the housing 1. Therefore, keeping 0.7 ≤ a / b ≤ 1 can enable the battery to have better current-carrying capacity.

[0042] In some embodiments, the adapter piece 2 and the battery cell body 31 are opposite and spaced apart on the side surface in the length direction of the outer shell 1. The tab 32 extends from the side surface of the battery cell body 31 in the length direction of the outer shell 1 and then is connected to the adapter piece 2. The size of the tab 32 in the height direction of the outer shell 1 is a, and the size of the adapter piece 2 in the height direction of the outer shell 1 is c, where 0.15 ≤ c / a ≤ 0.75 and 0.1 mm ≤ Y ≤ 2 mm. The value of c / a can be 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65 or 0.7.

[0043] That is, the size of the adapter piece 2 in the height direction of the outer shell 1 is made smaller than the size of the tab 32 in the height direction of the outer shell 1, so as to reduce the size of the adapter piece 2 and reduce the weight of the battery; at the same time, it is avoided that the ratio of the adapter piece 2 to the tab 32 is too small, resulting in insufficient welding area between the subsequent tab 32 and the adapter piece 2, leading to poor over-current capacity of the battery. In addition, by further controlling 0.1 mm ≤ Y ≤ 2 mm, the over-current capacity of the battery is further improved, and at the same time, it is avoided that the tab 32 rubs against the housing 12, causing the battery to short-circuit.

[0044] In some embodiments, the adapter piece 2 and the battery cell body 31 are opposite and spaced apart on the side surface in the length direction of the outer shell 1. The tab 32 extends from the side surface of the battery cell body 31 in the length direction of the outer shell 1. The tab 32 is provided with a first welding area 322 and a second welding area 323 at intervals in the height direction of the outer shell. The tab 32 is welded to the adapter piece 2 at the first welding area 322, and the area of the first welding area 322 is larger than the area of the second welding area 323, where 0.05 mm ≤ Y ≤ 2.5 mm.

[0045] Specifically, the tab 32 includes a plurality of sub-tabs 324 stacked together. The first welding area 322 and the second welding area 323 are provided at intervals in the height direction of the outer shell 1 on the tab 32, so as to prevent the plurality of sub-tabs 324 from being scattered; at the same time, since the first welding area 322 of the tab 32 needs to be welded to the adapter piece 2, the area of the first welding area 322 is made larger than the area of the second welding area 323, so as to ensure that the first welding area 322 has enough area to be welded to the adapter piece 2, which can facilitate the welding of the tab 32 to the adapter piece 2, and can ensure the contact area between the tab 32 and the adapter piece 2, improving the over-current capacity of the battery. Moreover, by controlling 0.05 mm ≤ Y ≤ 2.5 mm, the risk of the tab 32 rubbing against the outer shell 1 is further reduced, and the risk of battery short-circuit is reduced.

[0046] Furthermore, the first welding region 322 is formed by laser welding, and the second welding region 323 is formed by ultrasonic welding.

[0047] Combination Figure 5 As shown, in some embodiments, the pole ear 32 includes a plurality of sub-pole ears 324, which are gathered and bent along the width direction of the shell 1 and then connected to the adapter sheet 2. The pole ear 32 is formed with a gathering portion 325 at the position where the plurality of sub-pole ears 324 are gathered, and the gathering portion 325 corresponds to one side of the battery cell body 31 in the width direction of the shell 1 and close to the inner side surface of the shell 1. Specifically, the minimum distance between the gathering portion 325 and the outer edge of the battery cell body 31 is between 0-3 mm, wherein 20≤(Dd) / Y≤140.

[0048] Since the gathered portion 325 of the pole tab 32 is close to the inner side surface of the shell 1 , by further controlling 20≤(Dd) / Y≤140, the risk of overlapping and causing a short circuit between the bent portion 321 of the pole tab 32 and the shell 1 when the gathered portion 325 is arranged at the outer edge of the battery cell body 31 can be further reduced.

[0049] Combination Figure 6 As shown, in some embodiments, the pole ear 32 includes a plurality of sub-pole ears 324, which are gathered and bent along the width direction of the shell 1 and then connected to the adapter sheet 2, and the pole ear 32 forms a gathering portion 325 at the position where the plurality of sub-pole ears 324 are gathered, and the gathering portion 325 corresponds to the middle area of ​​the battery cell body 31 in the width direction of the shell 1. Specifically, the distance between the gathering portion 325 and the center line of a single battery cell body 31 is between 0-5 mm, wherein 10≤(Dd) / Y≤130.

[0050] Since the gathered portion 325 of the pole tab 32 corresponds to the middle area of ​​the battery cell body 31 in the width direction of the shell 1, after the multiple sub-pole tabs 324 are gathered, the bending portion 321 of the pole tab 32 is far away from the inner wall of the shell 1. By controlling 10≤(Dd) / Y≤130, the current carrying capacity of the battery can be further improved. At the same time, the distance between the adapter 2 and the shell 1 is controlled to improve the space utilization inside the shell 1.

[0051] Combination Figure 7As shown, in some embodiments, the pole ear 32 includes a plurality of sub-pole ears 324, and the plurality of sub-pole ears 324 are gathered and bent along the width direction of the shell 1 and then connected to the adapter sheet 2. The pole ear 32 is formed with a gathering portion 325 at the position where the plurality of sub-pole ears 324 are gathered, and the gathering portion 325 corresponds to a side of the battery cell body 31 in the width direction of the shell 1 and away from the inner side surface of the shell 1. Specifically, the distance between the gathering portion 325 and the inner edge of the battery cell body 31 is between 0-3 mm, wherein 8≤(Dd) / Y≤120.

[0052] Since the retracted portion 325 of the pole ear 32 corresponds to the side of the battery cell body 31 in the width direction of the shell 1 and away from the inner side surface of the shell 1, after the multiple sub-pole ears 324 are retracted, the bending portion 321 of the pole ear 32 is far away from the inner wall of the shell 1, thereby controlling the distance between the adapter 2 and the shell 1 and improving the space utilization inside the shell 1.

[0053] In some embodiments, an arc portion 14 is formed between the inner side wall of the shell 1 in the length direction and the inner side wall of the shell 1 in the width direction, and the bent portion 321 of the tab 32 is opposite to and spaced from the arc portion 14 , wherein 10≤(Dd) / Y≤150.

[0054] Since an arc portion 14 is formed between the inner side wall of the shell 1 in the length direction and the inner side wall of the shell 1 in the width direction, and the bent portion 321 of the pole ear 32 is opposite to the arc portion 14 and arranged at a distance, the bent portion 321 of the pole ear 32 is easy to contact with the arc portion 14 of the shell 1, and by further controlling 10≤(Dd) / Y≤150, the collision between the bent portion 321 and the arc portion 14 can be further avoided, the arc portion 14 can be prevented from exerting pressure on the pole ear 32, causing damage to the pole ear 32, and avoiding battery short circuit.

[0055] Preferably, the size of the arc portion 14 is R, wherein R≥0.5 mm, 15≤(Dd) / Y≤135. The value of R may be 0.6 mm, 0.7 mm, 0.8 mm or 0.9 mm.

[0056] Since the larger the size of the arc-shaped portion 14 is, the greater the risk of the tab 32 contacting the housing 1 is, so when R ≥ 0.5 mm, it is necessary to maintain 15 ≤ (Dd) / Y ≤ 135 to further reduce the risk of contact between the tab 32 and the housing 1, thereby reducing the risk of battery short circuit.

[0057] In some embodiments, the battery cell 3 is a laminated battery cell, and the tab 32 extends from a side surface of the battery cell body 31 in the length direction of the outer shell 1, where 10 mm ≤ D - d ≤ 25 mm and 0.05 mm ≤ Y ≤ 2 mm.

[0058] The laminated battery cell includes a positive electrode sheet, a negative electrode sheet, and a separator. The adjacent positive electrode sheets and the adjacent negative electrode sheets are not continuously arranged with each other, and the separator can be continuously arranged, such as a Z-shaped laminated battery cell, or the separator can also be discontinuously arranged. The stacking of the positive electrode sheet, the negative electrode sheet, and the separator in the laminated battery cell is relatively loose. After the tab 32 is led out from the battery cell body 31, the stacking of the multi-layer sub-tabs 324 is also relatively loose. Therefore, after the tab 32 is bent subsequently, the risk of contact between the tab 32 and the outer shell 1 becomes greater. By further controlling 10 mm ≤ D - d ≤ 25 mm and 0.05 mm ≤ Y ≤ 2 mm, the contact between the tab 32 and the outer shell 1 is avoided, and battery short circuit does not occur; moreover, the over-current capacity of the battery is taken into account at the same time.

[0059] In some embodiments, the battery cell 3 is a wound battery cell, where 8 mm ≤ D - d ≤ 20 mm and 0.08 mm ≤ Y ≤ 2.4 mm.

[0060] The wound battery cell is formed by winding a positive electrode sheet, a negative electrode sheet, and a separator. The adjacent positive electrode sheets, the adjacent negative electrode sheets, and the adjacent separators are all continuously arranged. The stacking of the positive electrode sheet, the negative electrode sheet, and the separator is relatively compact, and the stacking of the multi-layer sub-tabs 324 led out is also relatively compact. After the tab 32 is bent, the risk of contact between the tab 32 and the outer shell 1 is relatively low. By further controlling 8 mm ≤ D - d ≤ 20 mm and 0.08 mm ≤ Y ≤ 2.4 mm, the over-current capacity of the battery can be improved, and at the same time, the space utilization rate inside the outer shell 1 can be increased.

[0061] In some embodiments, the side of the outer shell 1 where the terminal post 11 is provided is not opposite to the side of the battery cell body 31 where the tab 32 is provided.

[0062] That is to say, the tab 32 and the terminal post 11 can be correspondingly located on different surfaces of the battery. Specifically, the tab 32 can extend from a side surface of the battery cell body 31 in the length direction of the outer shell 1, and the terminal post 11 is located at the top of the outer shell 1.

[0063] Preferably, the adapter piece 2 is in an L shape. The adapter piece 2 includes a first connecting portion 21 and a second connecting portion 22, and there is an included angle between the first connecting portion 21 and the second connecting portion 22, and the range of the included angle is 80° - 110°. The first connecting portion 21 is connected to the tab 32, and the second connecting portion 22 is electrically connected to the terminal post 11.

[0064] Specifically, the first connection part 21 is opposite to the side surface of the battery cell body 31 in the length direction of the outer shell 1, facilitating the connection between the tab 32 extending from the side surface of the battery cell body 31 in the length direction of the outer shell 1 and the first connection part 21. The second connection part 22 is located between the battery cell body 31 and the cover plate 13, so as to facilitate the connection between the second connection part 22 and the pole column 11.

[0065] In some embodiments, one side of the outer shell 1 provided with the pole column 11 is oppositely arranged to one side of the battery cell body 31 provided with the tab 32.

[0066] That is to say, both the tab 32 and the pole column 11 are located on the same side of the battery.

[0067] In some embodiments, the tab 32 includes a plurality of sub-tabs 324, and the thickness of the sub-tab 324 is y, where 0.002 mm ≤ y ≤ 0.015 mm. The value of y can also be 0.005 mm, 0.008 mm, 0.01 mm, 0.012 mm, 0.013 mm or 0.014 mm.

[0068] Since the thickness of y affects the thickness of the tab 32, it has an impact on the over-current capacity of the battery and also affects the risk of the tab 32 coming into contact with the outer shell 1. By controlling 0.002 mm ≤ y ≤ 0.015 mm, the over-current can be further improved, and at the same time, the risk of the tab rubbing against the shell and the battery short-circuiting, resulting in an increase in the battery temperature rise, can be avoided.

[0069] In some embodiments, an insulating layer 4 is provided on the side surface of the tab 32 close to the inner side wall of the outer shell 1, where 30 μm ≤ d ≤ 60 μm.

[0070] Through the arrangement of the insulating layer 4, the tab 32 can be protected, and the risk of the tab 32 rubbing against the inner side surface of the outer shell 1 can be reduced. By further controlling 30 μm ≤ d ≤ 60 μm, the protection effect on the tab 32 can be further improved.

[0071] The insulating layer 4 can be an insulating film, and the insulating film can be selected from PP, PET or PI. The present invention also relates to a battery pack including the battery.

[0072] By adopting the battery in the battery pack, the operation of the battery pack is made more stable.

[0073] The present invention also relates to an electrical device including the battery pack.

[0074] By adopting the battery pack in the electrical device, the operation of the electrical device is made more stable.

[0075] It should be noted that the preparation process of the battery is as follows (the selection of the positive electrode active material, negative electrode active material, conductive agent and binder below is only for example and does not limit the protection scope of the present application): (1) Preparation of the positive electrode sheet.

[0076] Mix the prepared positive electrode active material (such as nickel-cobalt-manganese ternary, lithium iron phosphate, lithium manganese iron phosphate), conductive agent acetylene black, and binder PVDF in a mass ratio of 96:2:2, add the solvent NMP, and stir under a vacuum mixer until the system becomes homogeneous to obtain the positive electrode slurry; uniformly coat the positive electrode slurry on both surfaces of the positive electrode current collector aluminum foil, dry it at room temperature and then transfer it to an oven for further drying, and then obtain the positive electrode sheet through cold pressing and slitting.

[0077] (2) Preparation of the negative electrode sheet.

[0078] Mix the negative electrode active material graphite or a mixture of graphite and other active materials (such as silicon-based materials) obtained in different mass ratios, conductive agent acetylene black, thickening CMC, and binder SBR in a mass ratio of 96.4:1:1.2:1.4, add the solvent deionized water, and stir under a vacuum mixer until the system becomes homogeneous to obtain the negative electrode slurry; uniformly coat the negative electrode slurry on both surfaces of the negative electrode current collector copper foil, dry it at room temperature and then transfer it to an oven for further drying, and then obtain the negative electrode sheet through cold pressing and slitting.

[0079] (3) Preparation of the electrolyte.

[0080] Mix ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) in a volume ratio of 1:1:1 to obtain an organic solvent, and then dissolve the fully dried lithium salt LiPF6 in the mixed organic solvent to prepare an electrolyte with a concentration of 1 mol / L.

[0081] (4) Preparation of the separator.

[0082] Select a polyethylene film as the separator.

[0083] (5) Preparation of the lithium-ion battery.

[0084] Prepare the above positive electrode sheet, separator, and negative electrode sheet in sequence through the stacking process, so that the separator is between the positive and negative electrode sheets to play an isolation role. After preparing the battery cell 3, put the battery cell 3 into the shell, weld the battery cover plate 13, and perform processes such as injecting electrolyte, forming, and constant volume on the battery.

[0085] In the present application, the distance between the two side walls of the housing 12 can be adjusted by the wall thickness of the housing 12, etc.; the width of the adapter piece 2 is adjusted by selecting the adapter piece 2; the thickness of the tab 32 is controlled by the thickness of the single-piece sub-tab 324 or the number of layers of the sub-tab 324.

[0086] In a specific embodiment of the present application, lithium iron phosphate is selected as the positive electrode; artificial graphite is selected as the negative electrode active material for illustration.

[0087] Among them, the method for testing the temperature of the battery cell 3 includes loading the battery cell 3 into the housing 12, sealing and welding the cover plate 13 and the housing 12, and a terminal post 11 is provided on the cover plate 13 to perform a temperature rise test on the battery. The specific test steps are as follows, where 1) For lithium iron phosphate batteries: Constant current charge at a rate of 4C to 3.65V and then constant voltage charge until the current drops to 0.05C; Connect a temperature sensor to the terminal post 11, and during the charging process, sample the temperature of the terminal post 11 to obtain the highest temperature T in the terminal post area. When the highest temperature T in the terminal post area ≤ 45°C, it is considered good; when 45°C < T ≤ 65°C, it is considered qualified; when T > 65°C, it is considered unqualified.

[0088] Insert the following table: It can be seen from Examples 1-10 and Comparative Examples 1 and 2 that when the formula range satisfies: 3 ≤ (D - d) / Y ≤ 150, the battery tab breakage rate is less than or equal to 20%; and the temperature rise of the battery terminal post is less than or equal to 65°C, and the temperature rise of the battery terminal post is qualified; Furthermore, combining Examples 1-5, it can be seen that when the formula range satisfies the preferred range of 5-125; and when the parameters satisfy the preferred range, when the battery cell is inserted into the housing, the tabs do not break; and the temperature rise of the battery terminal post is less than or equal to 45°C, and the temperature rise of the battery terminal post is good; It can be seen from Example 6 that when the parameters are not in the preferred range, but the formula is in the preferred range, the tabs show slight breakage, and the breakage rate is 1.5%; In Example 7, the tab thickness is relatively thin, and the battery temperature rise is qualified; In Example 8, when the parameters are within the preferred range, but the formula is not within the preferred range, the tabs break, and the breakage rate is 5.5%; In Example 9, the battery temperature rise is relatively large; In Example 10, the tabs break, and the breakage rate reaches 20%; In Comparative Example 1, the temperature rise of the battery terminal post is greater than 65°C, and the battery temperature rise is unqualified; In Comparative Example 2, when the battery cell is inserted into the housing, the tabs are severely broken; the battery temperature rise is unqualified. The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and substitutions can be made, and these improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A battery having a first direction, a second direction, and a third direction that intersect perpendicularly to each other, characterized in that, Comprising: A housing, on which a terminal post is provided; A connecting piece, which is arranged inside the housing and electrically connected to the terminal post; A battery cell, which is arranged inside the housing. The battery cell includes a battery cell body and a tab. The tab extends from the battery cell body. One end of the tab far from the battery cell body is bent along a first direction of the housing and then connected to a side of the connecting piece facing away from the battery cell, and a bent portion is formed at the bent position of the tab; Wherein, the distance between two inner side walls of the housing in the first direction is D mm, the size of the connecting piece in the first direction of the housing is d mm, the thickness of the tab is Y mm, and 3 ≤ (D - d) / Y ≤ 150.

2. The battery according to claim 1, characterized in that, 5 ≤ (D - d) / Y ≤ 125.

3. The battery according to claim 1, characterized in that, 5 mm ≤ D - d ≤ 30 mm and / or 0.05 mm ≤ Y ≤ 2.5 mm and / or 10 mm ≤ D ≤ 75 mm and / or 5 mm ≤ d ≤ 68 mm.

4. The battery according to claim 1, characterized in that, The overlapping size of the tab and the connecting piece in the first direction of the housing is L1 mm, wherein, L1 ≥ d / 2, and 8 ≤ (D - d) / Y ≤ 100.

5. The battery according to claim 1, characterized in that, The overlapping size of the tab and the connecting piece in the first direction of the housing is L1 mm, wherein, d / 4 ≤ L1 < d / 2, and 8 ≤ (D - d) / Y ≤ 80.

6. The battery according to claim 1, wherein, There is one battery cell, and the overlapping size of the tab and the connecting piece in the first direction of the housing is L1 mm, wherein, 0.4 ≤ L1 / d ≤ 0.9, and 8 ≤ (D - d) / Y ≤ 125.

7. The battery according to claim 1, wherein, There are at least two battery cells arranged along the first direction of the housing. The overlapping size of the tab of a single battery cell and the connecting piece in the first direction of the housing is L1 mm, wherein, 0.2 ≤ L1 / d ≤ 0.45, and 25 ≤ (D - d) / Y ≤ 125.

8. The battery according to claim 1, wherein The housing includes a shell and a cover plate. In a third direction of the housing, at least one side of the shell has an opening, and the cover plate is covered at the opening, and the terminal post is arranged on the cover plate; The connecting piece and the side surface of the battery cell body are opposite and spaced in a second direction of the housing. The tab extends from the side surface of the battery cell body in the second direction of the housing and then is connected to the connecting piece. In the third direction of the housing, the distance between one end of the tab close to the cover plate and the cover plate is h1 mm, and the distance between one end of the connecting piece close to the cover plate and the cover plate is h2 mm, wherein, h2 < h1.

9. The battery according to claim 8, characterized in that, 1 mm ≤ h1 - h2 ≤ 8 mm.

10. The battery according to claim 1, characterized in that, The tab extends from the side surface of the battery cell body in the second direction of the housing. The size of the tab in the third direction of the housing is a mm, and the size of the battery cell body in the third direction of the housing is b mm, wherein, 0.7 ≤ a / b ≤ 1.

11. The battery according to claim 1, characterized in that, The adapter plate is opposite to and spaced from the side surface of the battery cell body in the second direction of the shell, the pole ear extends from the side surface of the battery cell body in the second direction of the shell and is connected to the adapter plate, the size of the pole ear in the third direction of the shell is amm, and the size of the adapter plate in the third direction of the shell is cmm, wherein 0.15≤c / a≤0.75, 0.1mm≤Y≤2mm.

12. The battery according to claim 1, characterized in that, The adapter plate is opposite to and spaced from the side surface of the battery cell body in the second direction of the shell, the pole ear extends from the side surface of the battery cell body in the second direction of the shell, and the pole ear is spaced from a first welding area and a second welding area along the third direction of the shell, the pole ear is welded to the adapter plate in the first welding area, the area of ​​the first welding area is larger than the area of ​​the second welding area, wherein 0.05mm≤Y≤2.5mm.

13. The battery according to claim 1, characterized in that, The pole tab includes a plurality of sub-pole tabs, which are gathered and bent along the first direction of the shell and then connected to the adapter sheet. The pole tab is formed with a gathering portion at the position where the plurality of sub-pole tabs are gathered, and the gathering portion corresponds to one side of the battery cell body in the first direction of the shell and close to the inner side surface of the shell, wherein 20≤(Dd) / Y≤140.

14. The battery according to claim 1, characterized in that, The pole tab includes a plurality of sub-pole tabs, which are gathered and bent along the first direction of the shell and then connected to the adapter sheet. The pole tab forms a gathered portion at the position where the plurality of sub-pole tabs are gathered, and the gathered portion corresponds to the middle area of ​​the battery cell body in the first direction of the shell, wherein 10≤(Dd) / Y≤130.

15. The battery according to claim 1, characterized in that, The pole tab includes a plurality of sub-pole tabs, which are gathered and bent along the first direction of the shell and then connected to the adapter sheet. The pole tab is formed with a gathering portion at the position where the plurality of sub-pole tabs are gathered, and the gathering portion corresponds to a side of the battery cell body in the first direction of the shell and away from the inner side surface of the shell, wherein 8≤(Dd) / Y≤120.

16. The battery according to claim 1, characterized in that, An arc portion is formed between the inner side wall of the shell in the second direction and the inner side wall of the shell in the first direction, and the bent portion of the tab is opposite to and spaced from the arc portion, wherein 10≤(Dd) / Y≤150.

17. The battery according to claim 16, characterized in that, The size of the arc portion is R, wherein R≥0.5 mm, 15≤(Dd) / Y≤135.

18. The battery according to claim 17, characterized in that, The battery core is a laminated battery core, and the pole ear extends from the side of the battery core body in the second direction of the shell, wherein 10mm≤Dd≤25mm, and 0.05mm≤Y≤2mm.

19. The battery according to claim 1, characterized in that, The battery cell is a wound battery cell, wherein 8mm≤Dd≤20mm, and 0.08mm≤Y≤2.4mm.

20. The battery according to claim 1, characterized in that, The side of the shell on which the pole is arranged is not opposite to the side of the battery cell body on which the pole ear is arranged.

21. The battery according to claim 20, wherein, The adapter piece includes a first connection part and a second connection part, and there is an included angle between the first connection part and the second connection part. The first connection part is connected to the tab, and the second connection part is connected to the terminal post.

22. The battery according to claim 1, characterized in that, One side of the housing where the terminal post is provided is disposed opposite to one side of the battery cell body where the tab is provided.

23. The battery according to claim 1, wherein The tab includes a plurality of sub-tabs, and the thickness of the sub-tab is y, where 0.002 mm ≤ y ≤ 0.015 mm.

24. The battery according to claim 1, wherein, An insulating layer is provided on the side of the tab close to the inner side wall of the housing, where 30 μm ≤ d ≤ 60 μm.

25. A battery pack, characterized in that, A battery according to any one of claims 1-24.

26. An electrical device, characterized in that, A battery pack according to claim 25.

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