Battery and battery pack

Abstract

The invention relates to the technical field of new energy, and discloses a battery and a battery pack. A pole; the laminated battery cell comprises a battery cell body and a tab extending from one end of the battery cell body along the first direction; the pole lugs are electrically connected with the pole columns; the tabs comprise a positive tab and a negative tab, and the positive tab and the negative tab are both located at the same end of the battery cell body in the first direction; the positive electrode lug and the negative electrode lug are arranged at an interval along a second direction, and the second direction is perpendicular to the first direction; the spacing distance between the positive pole lug and the negative pole lug along the second direction is a1, the width of the laminated battery cell along the second direction is a2, a = a1 / a2, the length of the battery cell body along the first direction is b, and b.a is more than or equal to 8mm and less than or equal to 350mm. According to the battery provided by the invention, the over-large b.a easily causes the increase of the over-current demand of the battery cell and the reduction of the area of the welding region. And too small battery energy density is low.

Description

Technical Field

[0001] The present invention relates to the field of new energy technologies, and particularly to a battery and a battery pack. Background Art

[0002] A stacked cell is a cell manufactured by a stacking process. By laminating a plurality of single-piece electrode sheets to form a stacked cell. A stacked cell is generally composed of a positive electrode sheet, a separator, a negative electrode sheet, etc. The stacked cell improves the overall space utilization rate inside a square battery and avoids risks such as lithium deposition that are likely to occur at the ends of the electrode sheets.

[0003] However, during the lamination process of the electrode sheets, the alignment between the ends of the electrode sheets is poor, and there is a risk of misalignment between the electrode sheets, resulting in a reduction in the overall current-carrying area of the electrode tabs, thereby affecting the current-carrying capacity of the stacked cell. Summary of the Invention

[0004] In view of this, the present invention provides a battery and a battery pack to solve the problem of how to effectively ensure the current-carrying capacity of a stacked cell.

[0005] In a first aspect, the present invention provides a battery, comprising:

[0006] A housing;

[0007] A terminal, disposed on the housing;

[0008] A stacked cell, disposed inside the housing, the stacked cell comprising a cell body and an electrode tab extending from one end of the cell body along a first direction; the electrode tab is adapted to be electrically connected to the terminal;

[0009] The electrode tab includes a positive electrode tab and a negative electrode tab, and both the positive electrode tab and the negative electrode tab are located at the same end of the cell body along the first direction; and the positive electrode tab and the negative electrode tab are spaced apart along a second direction, wherein the second direction is perpendicular to the first direction;

[0010] The spacing distance between the positive electrode tab and the negative electrode tab along the second direction is a1, the width of the stacked cell along the second direction is a2, and a = a1 / a2, and the length of the cell body along the first direction is b, in mm; satisfying: 8 mm ≤ b·a ≤ 350 mm.

[0011] Advantageous Effects: By comprehensively controlling a and b, if the formula value is too large, it is likely to affect the subsequent electrical connection between the positive electrode tab, the negative electrode tab and the cover plate, resulting in insufficient current-carrying capacity of the cover plate and the positive electrode tab, the negative electrode tab, thereby causing insufficient current-carrying capacity of the battery, which is likely to lead to an increase in the battery temperature rise and affect the battery safety; if the formula value is too small, it is likely to cause the positive electrode tab and the negative electrode tab to be easily vibrated or the distance is too close, resulting in lamination or current arcing, triggering the risk of internal short circuit of the battery.

[0012] In a second aspect, the present invention also provides a battery pack, which includes a plurality of batteries as described above, and further includes a bottom plate, and the batteries are fixed on the bottom plate.

[0013] Since the battery pack includes batteries and has the same effects as the batteries, they will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0015] Figure 1 Schematic diagram of the battery of the present invention;

[0016] Figure 2 Exploded state schematic diagram of the battery of the present invention;

[0017] Figure 3 Partial enlarged view of the battery of the present invention in the exploded state;

[0018] Figure 4 Partial enlarged view of the battery cell of the present invention;

[0019] Figure 5 Side view of the battery cell of the present invention;

[0020] Figure 6 For Figure 5 Schematic diagram of the A-A cross-section in

[0021] Figure 7 Schematic diagram of the stacked state of the positive electrode sheet and the negative electrode sheet of the present invention;

[0022] Figure 8 Cross-sectional view of the battery cell when the tab is in the unfolded state of the present invention;

[0023] Figure 9 For Figure 4 Schematic diagram of the B-B cross-section in

[0024] Figure 10 Side view of the electrode sheet of the present invention;

[0025] Figure 11 Cross-sectional schematic diagram of another battery cell of the present invention.

[0026] Description of the reference numerals:

[0027] 1. Housing; 11. Cover plate; 12. Housing body; 121. Opening part;

[0028] 2. Battery cell; 21. Tab; 211. Positive tab; 212. Negative tab; 22. Battery cell body;

[0029] 20. Electrode plate; 201. Positive electrode plate; 202. Negative electrode plate; 23. Electrode plate body; 24. Protrusion;

[0030] 3. Terminal. Detailed implementation manners

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0033] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0035] The stacked cell is a cell manufactured by the stacking process. By stacking multiple single-layer electrode sheets to form a stacked cell. The stacked cell is usually composed of a positive electrode sheet, a separator, and a negative electrode sheet, etc. The multiple positive electrode sheets and multiple negative electrode sheets are separated from each other. However, there are differences in the areas of the positive electrode sheet, the separator, and the negative electrode sheet, and the adjacent positive electrode sheets or adjacent negative electrode sheets are not continuous. After stacking, it is very difficult to ensure that the projections of the electrode sheets with the same polarity completely overlap. At the same time, since the single-layer electrode sheet extends to form an electrode tab, during the stacking process of the stacked cell, the alignment of the edges of the electrode sheets with the same polarity is poor during the stacking process, causing the electrode sheets to be misaligned, and then causing the positions of the electrode tabs to shift, affecting the current-carrying area of the overall connection between the electrode tabs and the terminal assembly, affecting the overall charge and discharge rate of the battery, and then easily causing a large temperature rise in the battery, affecting battery safety; it is found that when the positive and negative electrode tabs are arranged on the same side of the stacked cell, the problem of electrode tab misalignment is particularly serious. Due to the misalignment between the positive and negative electrode tabs, there are risks such as internal short circuit caused by the overlap of the positive and negative electrode tabs.

[0036] During the subsequent welding process of the electrode tab, the welding area needs to be set in the area where the multiple electrode tabs completely overlap to ensure that all electrode sheets can be electrically connected. When the misalignment of the electrode tab is serious, the non-completely overlapping area cannot be used as the welding area to avoid the situation where one or several electrode tabs are not welded. This leads to a reduction in the area of the welding area due to the limitation of the welding area when the misalignment of the electrode tab is serious, and then leads to a reduction in the current-carrying capacity of the cell, affecting the charge and discharge speed of the battery, and even causing serious local heating, with great potential safety hazards.

[0037] The following will describe the embodiments of the present invention in conjunction with Figures 1 to 11 ,

[0038] According to an embodiment of the present invention, on the one hand, a battery is provided, including:

[0039] A housing 1;

[0040] A terminal 3, arranged on the housing 1;

[0041] A stacked cell 2, arranged inside the housing 1. The stacked cell 2 includes a cell body 22 and an electrode tab 21 extending from one end of the cell body 22 along the first direction; the electrode tab 21 is adapted to be electrically connected to the terminal 3;

[0042] The electrode tab 21 includes a positive electrode tab 211 and a negative electrode tab 212. Both the positive electrode tab 211 and the negative electrode tab 212 are located at the same end of the cell body 22 along the first direction; and the positive electrode tab 211 and the negative electrode tab 212 are arranged at intervals along the second direction, where the second direction is perpendicular to the first direction;

[0043] The spacing distance a1 between the positive electrode tab 211 and the negative electrode tab 212 in the second direction, the width a2 of the stacked cell 2 in the second direction, satisfy a = a1 / a2, the length of the cell body 22 in the first direction is b, with the unit of mm; and satisfy: 8mm ≤ b·a ≤ 350mm.

[0044] The battery of this embodiment can be a square shell battery, a blade battery, etc. The stacked cell 2 can specifically be a cell manufactured by a stacking process.

[0045] In this embodiment, the first direction can be the length direction of the cell body 22, the second direction can be the width direction of the cell body 22. Specifically, in this embodiment, the second direction can be the direction perpendicular to the surface of the stacked cell 2 where the tabs 21 are led out, and the third direction can be the thickness direction of the cell body 22.

[0046] a2 refers to the width of the stacked cell 2 in the second direction, and specifically in this embodiment, it can be the dimension of the end face of the stacked cell 2 where the tabs 21 are provided in the second direction.

[0047] Combined with Figure 6 and Figure 11 shown, the end face of the stacked cell 2 where the tabs 21 are led out can specifically be the side face or the top face.

[0048] As an optional implementation form, combined with Figure 4 shown, the positive electrode tab 211 can be divided into two parts in the third direction, and both parts of the tabs are folded towards the middle area, which is convenient for realizing the parallel connection of the two parts of the tabs. Then, they are electrically connected to the cover plate together, reducing the current transmission impedance of the tabs and being beneficial to improving the overcurrent capacity of the cover plate and the positive electrode tab. The negative electrode tab 212 can adopt the same design.

[0049] The material of the housing 1 can include: aluminum, aluminum alloy (such as aluminum manganese alloy, aluminum magnesium alloy, etc.), steel, stainless steel, carbon steel, nickel-plated steel, titanium, titanium alloy, etc.

[0050] The material of the terminal 3 can include: metal materials such as aluminum, aluminum alloy, copper-aluminum composite, nickel, etc.

[0051] The stacked cell 2 is formed by stacking a positive electrode sheet 201, a negative electrode sheet 202, and a separator disposed between the two to form the cell body 22.

[0052] The positive electrode sheet 201 includes a positive electrode current collector and a positive electrode active material. The positive electrode current collector can be a metal material such as aluminum foil, nickel foil, stainless steel, etc., or a composite foil material formed by the combination of a metal and an insulating material, etc. 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 of lithium-containing positive electrode active materials such as lithium iron phosphate, ternary materials containing nickel cobalt manganese, lithium manganese iron phosphate, etc.;

[0053] The negative electrode sheet 202 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, etc., or can be a composite foil formed by combining 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 of negative electrode active main materials such as artificial graphite, natural graphite, silicon-carbon, silicon-oxygen, lithium titanate, etc.

[0054] The laminated cell 2 extends out the electrode tab 21, and the electrode tab 21 is adapted to be electrically connected to the electrode post 3; the electrode tab 21 serves as the output end of the laminated cell 2, and the electrode post 3 serves as the output end of the battery. The electrode tab 21 can be electrically connected to the electrode post 3 by welding with the adapter piece 4, or can be directly welded to the electrode post 3 to achieve electrical connection. The welding can adopt methods such as ultrasonic welding, resistance welding or laser welding.

[0055] Since the positive electrode tab 211 and the negative electrode tab 212 are respectively led out from both ends of the cell body 22 along the first direction, the battery needs to reserve space for arranging the electrode tabs at both ends of the housing 1 along the first direction, which is likely to lead to a reduction in the space utilization rate of the battery. In this embodiment, both the positive electrode tab 211 and the negative electrode tab 212 are led out from the same end of the cell body 22 along the first direction, so that the battery only needs to reserve space for arranging the electrode tabs at one end of the housing 1 along the first direction, thereby improving the space utilization rate of the battery.

[0056] Since the positive electrode tab 211 and the negative electrode tab 212 are led out from the same end of the cell body 22 along the first direction, and the positive electrode tab 211 and the negative electrode tab 212 carry opposite charges, the positive electrode tab 211 and the negative electrode tab 212 need to be insulated. In this embodiment, by arranging the positive electrode tab 211 and the negative electrode tab 212 at intervals along the second direction, the overlap of the positive and negative electrode tabs is prevented. However, the electrode sheets of the laminated cell are separated from each other. Therefore, under certain working conditions or when the stacking alignment is poor, the positive and negative electrode tabs are prone to vibration or being close to each other, resulting in overlap or arcing of the current, leading to the risk of internal short circuit of the battery.

[0057] However, since the area of the end face of the cell body 22 is limited, when the positive electrode tab 211 and the negative electrode tab 212 are led out from the same end of the cell body 22 along the first direction, the sizes of the positive electrode tab 211 and the negative electrode tab 212 are likely to be limited, which in turn affects the over-current capacity of the laminated cell 2. In this embodiment, by further restricting the relationship between a and b, the electrical connection between the positive electrode tab 211, the negative electrode tab 212 and the cover plate is improved, the overall over-current capacity of the battery is enhanced, and at the same time, the overlap between the positive electrode tab 211 and the negative electrode tab 212 is avoided, especially when being vibrated or being close to each other, the arcing of the current is avoided, the internal short circuit of the battery is prevented, and the over-current capacity of the laminated cell 2 is improved.

[0058] By comprehensively controlling a and b, if the formula value is too large, it is likely to affect the subsequent electrical connection between the positive electrode tab 211, the negative electrode tab 212 and the cover plate, resulting in insufficient overcurrent capacity of the cover plate, the positive electrode tab 211 and the negative electrode tab 212, and further insufficient overcurrent capacity of the battery; if the formula value is too small, it is likely that the positive electrode tab 211 and the negative electrode tab 212 are vulnerable to vibration or are close in distance, resulting in lapping or arcing of the current, triggering the risk of internal short circuit of the battery.

[0059] Combined with Table 1 below, through a number of examples and comparative examples for testing, the overcurrent capacity and the risk of internal short circuit of the provided battery are tested.

[0060]

[0061]

[0062] Examples 1-14 and Comparative Examples 1-2 use ternary positive electrodes. Examples 15-17 and Comparative Examples 3-4 use lithium iron phosphate (abbreviation: LFP) positive electrodes.

[0063] First, regarding the batteries used in Examples 1-14 and Comparative Examples 1-2, their specific preparation methods are as follows:

[0064] (1) Preparation of the positive electrode sheet:

[0065] Mix the prepared positive electrode active material LiNi 0.6 Co 0.2 Mn 0.2 O2, conductive agent acetylene black, and binder PVDF in a mass ratio of 95:3:2, add the solvent NMP, and stir under a vacuum mixer until the system is homogeneous to obtain a positive electrode slurry; uniformly coat the positive electrode slurry on both surfaces of the positive electrode current collector aluminum foil, dry at room temperature and then transfer to an oven for further drying, and then obtain the positive electrode sheet through cold pressing and slitting.

[0066] (2) Preparation of the negative electrode sheet:

[0067] Mix the negative electrode active material graphite, conductive agent acetylene black, thickening CMC, and binder SBR in a mass ratio of 96:1:1.5:1.5, add the solvent deionized water, and stir under a vacuum mixer until the system is homogeneous to obtain a negative electrode slurry; uniformly coat the negative electrode slurry on both surfaces of the negative electrode current collector copper foil, dry at room temperature and then transfer to an oven for further drying, and then obtain the negative electrode sheet through cold pressing and slitting.

[0068] (3) Preparation of the electrolyte:

[0069] Ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a volume ratio of 1:1:1 to obtain an organic solvent. Then, the fully dried lithium salt LiPF6 was dissolved in the mixed organic solvent to prepare an electrolyte solution with a concentration of 1 mol / L.

[0070] (4) Preparation of the separator:

[0071] A polyethylene film was selected as the separator.

[0072] (5) Preparation of the lithium-ion battery:

[0073] The above positive electrode sheet, separator, and negative electrode sheet were prepared in sequence through the stacking process, with the separator placed between the positive and negative electrode sheets to play an insulating role. After the battery cell was prepared, the bare battery cell was inserted into the shell from the opening 121 of the shell body 12, and the cover plate 11 and the shell body 12 were welded by laser sealing; after drying, the electrolyte was injected, and through processes such as vacuum packaging, standing, formation, and shaping, the battery was obtained.

[0074] In Examples 15 - 17 and Comparative Examples 3 - 4, the positive electrode material was adjusted to lithium iron phosphate, and the rest remained unchanged.

[0075] Performance Test 1:

[0076] Internal short-circuit test, which can detect whether there is a short-circuit risk in the battery. The specific test method is as follows:

[0077] For the bare battery cells obtained in Examples 1 - 15 and Comparative Examples 1 - 4, vibration tests were carried out. The vibration tests refer to the following text, and at the same time, the circuit was connected for voltage testing. The positive electrode tab and negative electrode tab of the bare battery cell were respectively connected to the electrodes, and the voltage between the positive electrode tab and the negative electrode tab was tested; for the battery cell obtained from the positive electrode active material LiNi 0.6 Co 0.2 Mn 0.2 O2, if the voltage between the positive electrode tab and the negative electrode tab tested is between 4.2 - 4.3V, it indicates that the voltage between the positive and negative electrode tabs is normal; if the voltage between the positive electrode tab and the negative electrode tab tested is between 3.8V - 4.2V (less than), it indicates a micro short-circuit; if the voltage between the positive and negative electrode tabs measured is less than 1V, it indicates that a short-circuit has occurred between the positive and negative electrode tabs.

[0078] For lithium iron phosphate batteries, if the voltage between the positive electrode tab and the negative electrode tab tested is between 3.5 - 3.7V, it indicates that the voltage between the positive and negative electrode tabs is normal; if the voltage between the positive electrode tab and the negative electrode tab tested is between 3.0V - 3.5V, it indicates a micro short-circuit; if the voltage between the positive and negative electrode tabs measured is less than 1V, it indicates that a short-circuit has occurred between the positive and negative electrode tabs.

[0079] For the above tests, 5 samples are tested in parallel for each group.

[0080] Vibration test method: The vibration parameters are tested according to the following requirements.

[0081] Install the battery cell on the vibration table and perform up and down vibration. The vibration frequency is 10 Hz - 55 Hz, and the maximum acceleration is 30 m / s 2 ; The vibration time is 3 h.

[0082] Performance test two:

[0083] The pole post temperature rise test can measure the overcurrent capacity of the battery. Among them, the cover plate is provided with a pole post, and the temperature rise test of the battery is carried out. The specific test method is as follows:

[0084] 1) For lithium iron phosphate batteries: Constant current charge at a rate of 3C to 3.65 V and constant voltage charge until the current drops to 0.05C; Connect a temperature sensor to the pole post and sample the temperature of the pole post during the charging process;

[0085] 2) For batteries with the positive active material LiNi 0.6 Co 0.2 Mn 0.2 O2, constant current charge at a rate of 3C to 4.25 V and constant voltage charge until the current drops to 0.05C; Connect a temperature sensor to the pole post and sample the temperature of the pole post during the charging process;

[0086] Sample the temperature of the pole post to obtain the highest temperature T in the pole post area. When the highest temperature T in the pole 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.

[0087] For the above tests, 5 samples are tested in parallel for each group.

[0088] Combined with Table 1 above, the explanation is as follows:

[0089] In Examples 1 - 11, the value of b·a satisfies: 8 mm ≤ b·a ≤ 350 mm. After performance test one, the voltage between the positive and negative pole ears is normal, and no short circuit occurs in the internal short circuit test results, meeting the performance requirements. After performance test two, the pole post temperature rise is less than or equal to 45°C, and the temperature control is good, meeting the performance requirements.

[0090] In Example 12, the value of b·a satisfies: 8 mm ≤ b·a ≤ 350 mm. However, due to the relatively small value of a, after performance test one, the voltage between the positive and negative pole ears is small, and micro short circuits are likely to occur, posing a certain safety hazard. After performance test two, the pole post temperature rise is less than or equal to 45°C, and the temperature control is good, meeting the performance requirements.

[0091] In Example 13, the value of b·a satisfies: 8 mm ≤ b·a ≤ 350 mm. However, due to the relatively large value of a, after Performance Test 1, the voltage between the positive and negative electrode tabs is normal, and no short circuit occurs in the internal short circuit test results, meeting the performance requirements. After Performance Test 2, the temperature rise is greater than 45 °C and less than or equal to 65 °C, and the temperature control is qualified, basically meeting the performance requirements.

[0092] In Example 14, the value of b·a satisfies: 8 mm ≤ b·a ≤ 350 mm. However, due to the relatively small value of a and the relatively large value of b, after Performance Test 1, the voltage between the positive and negative electrode tabs is small, and micro short circuits are likely to occur, posing a certain safety hazard. After Performance Test 2, the temperature rise is greater than 45 °C and less than or equal to 65 °C, and the temperature control is qualified, basically meeting the performance requirements.

[0093] In Comparative Example 1, the value of b·a is less than the lower limit of the formula value. After Performance Test 1, the voltage between the positive and negative electrode tabs is less than 1 V, the voltage value is abnormal, and short circuits are likely to occur, posing a relatively large safety hazard. After Performance Test 2, the temperature rise is greater than 65 °C, and the temperature control is unqualified, unable to meet the performance requirements.

[0094] In Comparative Example 2, the value of b·a is greater than the upper limit of the formula value. After Performance Test 1, the voltage between the positive and negative electrode tabs is normal, and no short circuit occurs in the internal short circuit test results, meeting the performance requirements. However, after Performance Test 2, the temperature rise is greater than 65 °C, and the temperature control is unqualified, unable to meet the performance requirements.

[0095] In Example 15, the value of b·a satisfies: 8 mm ≤ b·a ≤ 350 mm. After Performance Test 1, the voltage between the positive and negative electrode tabs is normal, and no short circuit occurs in the internal short circuit test results, meeting the performance requirements. After Performance Test 2, the temperature rise of the terminal posts is less than or equal to 45 °C, and the temperature control is good, meeting the performance requirements.

[0096] In Example 16, the value of b·a satisfies: 8 mm ≤ b·a ≤ 350 mm. However, due to the relatively large value of a, after Performance Test 1, the voltage between the positive and negative electrode tabs is normal, and no short circuit occurs in the internal short circuit test results, meeting the performance requirements. After Performance Test 2, the temperature rise is greater than 45 °C and less than or equal to 65 °C, and the temperature control is qualified, basically meeting the performance requirements.

[0097] In Example 17, the value of b·a satisfies: 8 mm ≤ b·a ≤ 350 mm. However, due to the relatively small value of a and the relatively large value of b, after Performance Test 1, the voltage between the positive and negative electrode tabs is small, and micro short circuits are likely to occur, posing a certain safety hazard. After Performance Test 2, the temperature rise is greater than 45 °C and less than or equal to 65 °C, and the temperature control is qualified, basically meeting the performance requirements.

[0098] In Comparative Example 3, the value of b·a is less than the lower limit of the formula value. After Performance Test 1, the voltage between the positive and negative electrode tabs is less than 1V, and the voltage value is abnormal, which is prone to short circuit and poses a greater safety hazard. After Performance Test 2, the temperature rise is greater than 65°C, and the temperature control is unqualified and cannot meet the performance requirements.

[0099] In Comparative Example 4, the value of b·a is greater than the upper limit of the formula value. After Performance Test 1, the voltage between the positive and negative electrode tabs is normal, and no short circuit occurs in the internal short circuit test result, meeting the performance requirements. However, after Performance Test 2, the temperature rise is greater than 65°C, and the temperature control is unqualified and cannot meet the performance requirements.

[0100] Exemplarily, in this embodiment, the value of b·a can be 8mm or 10mm or 12mm or 15mm or 18mm or 20mm or 26mm or 36mm or 55mm or 72mm or 80mm or 150mm or 180mm or 210mm or 225mm or 310mm or 350mm, etc., or it can also be an interval range formed by any two of the above numerical values.

[0101] By reasonably setting the value of b·a, on the one hand, it can ensure the subsequent electrical connection area between the positive electrode tab 211 and the negative electrode tab 212 and the cover plate, ensuring the overcurrent capacity of the battery cell; on the other hand, it can reduce the risk of short circuit caused by tab short circuit.

[0102] In some embodiments, the housing 1 includes a housing body 12 and a cover plate 11. At least one end of the housing body 12 in the first direction is provided with an opening 121, and the cover plate 11 is arranged to block the opening 121;

[0103] The battery further includes a terminal assembly. The terminal assembly is arranged on the cover plate 11, and the tab 21 is led out towards the cover plate 11; satisfying: 8mm ≤ b·a ≤ 300mm.

[0104] It should be noted that the terminal assembly may include a terminal 3 and / or an adapter plate 4. The tab 21 can be directly welded to the terminal 3 to achieve electrical connection; or, the tab 21 can also be welded to the adapter plate 4, and the adapter plate 4 is used for transfer to achieve electrical connection with the terminal 3.

[0105] The structural form adopted in this embodiment is to open an opening 121 in the housing body 12 and arrange the cover plate 11 to block the opening 121. By arranging the terminal assembly on the cover plate 11 and leading out the tab 21 towards the cover plate 11, it is convenient for the assembly of the tab 21 and the terminal 3, avoiding the situation where it is difficult to accurately align and connect the tab 21 and the terminal assembly after the electrode sheet 20 is misaligned, improving the overall assembly efficiency of the battery, and at the same time improving the overcurrent transmission capacity. Controlling the formula range of b·a within 8mm - 300mm can reduce the risk of internal short circuit between the positive and negative electrode tabs.

[0106] In some embodiments, the laminated battery cell 2 includes a positive electrode sheet 201 and a negative electrode sheet 202; the negative electrode sheet 202 extends beyond the positive electrode sheet 201 along a first direction, satisfying: 12 mm ≤ b·a ≤ 350 mm.

[0107] It exacerbates the risk of misalignment, affects the overcurrent. By controlling the formula range of b·a within 12 mm - 350 mm, it is possible to avoid a decrease in overcurrent and prevent an increase in battery temperature rise.

[0108] The negative electrode sheet 202 extending beyond the positive electrode sheet 201 along the first direction can prevent the lithium ions that have escaped from the positive electrode from causing lithium plating on the negative electrode due to insufficient lithium intercalation space after reaching the negative electrode. However, the form of the negative electrode sheet 202 extending beyond the positive electrode sheet 201 also makes the alignment of the ends of the electrode sheets stacked worse, resulting in misalignment of the electrode tabs 21 driven by the electrode sheet 20, exacerbating the risk of misalignment, affecting the overall welding area of the electrode tabs 21, affecting the overcurrent, and further resulting in a poor current transmission rate of the electrode tabs 21 and serious heat generation inside the laminated battery cell 2. By controlling the formula range of b·a within 12 mm - 350 mm, it is possible to avoid a decrease in overcurrent, prevent an increase in battery temperature rise, and improve the battery charging rate.

[0109] In some embodiments, in combination with Figure 7 as shown, the size by which the negative electrode sheet 202 extends beyond the positive electrode sheet 201 along the first direction is p, satisfying 1 mm ≤ p ≤ 3 mm.

[0110] Exemplarily, in this embodiment, the value of p can be 1 mm or 1.1 mm or 1.2 mm or 1.5 mm or 1.8 mm or 2 mm or 2.6 mm or 2.9 mm or 3 mm, etc., or it can also be an interval range formed by any two of the above values.

[0111] In some embodiments, in combination with Figure 10 as shown, the laminated battery cell 2 includes a plurality of electrode sheets 20 stacked on top of each other. The electrode sheet 20 includes an electrode sheet body 23 and an electrode tab 21 led out from the electrode sheet body 23. The electrode sheet body 23 is provided with a convex portion 24 protruding in a direction perpendicular to the large surface of the electrode sheet body 23, satisfying: 10 mm ≤ b·a ≤ 320 mm.

[0112] The electrode sheet body 23 is provided with a convex portion 24 protruding in a direction perpendicular to the large surface of the electrode sheet body 23, which can increase the friction between the electrode sheets 20, thereby at least to a certain extent reducing the relative movement between the plurality of electrode tabs 21 during handling, reducing the risk of short circuit between the positive and negative electrode tabs, enabling good positioning between adjacent electrode sheets, slowing down the impact of electrode sheet misalignment. By controlling the formula range of b·a within 10 mm - 320 mm, it is possible to avoid the lap joint of adjacent positive and negative electrode sheets.

[0113] In some embodiments, there are multiple protruding portions 24, and the multiple protruding portions 24 are arranged at intervals along the second direction.

[0114] By providing multiple protruding portions 24, the positioning effect between adjacent pole pieces can be improved, and the influence of pole piece misalignment can be further reduced.

[0115] In some embodiments, the height by which the protruding portion protrudes in the direction perpendicular to the large surface of the pole piece body 23 is q, and 0.5 mm ≤ q ≤ 2 mm is satisfied.

[0116] If the height by which the protruding portion protrudes is too low, the acting force for increasing friction will be weak, and the effect of reducing the relative movement of the pole tabs cannot be achieved, and thus the effect of reducing the short-circuit risk between the positive and negative pole tabs cannot be achieved. The height by which the protruding portion protrudes cannot be too high either, to avoid affecting the transmission of lithium ions between the positive and negative pole pieces.

[0117] Exemplarily, in this embodiment, the value of q can be 0.5 mm or 0.6 mm or 0.8 mm or 1 mm or 1.2 mm or 1.5 mm or 1.8 mm or 2 mm, etc., or it can also be the range formed by any two of the above numerical values.

[0118] In some embodiments, the battery further includes: a connecting piece 4, and the connecting piece 4 is electrically connected between the pole tab 21 and the pole post 3, and a part of the pole tab 21 is arranged on the surface of the connecting piece 4 facing away from the stacked battery cell 2; and 8 mm ≤ b · a ≤ 290 mm is satisfied.

[0119] A part of the pole tab 21 is arranged on the surface of the connecting piece 4 facing away from the stacked battery cell 2, which can improve the overall space utilization rate inside the battery, shorten the current transmission path between the pole tab 21 and the pole post 3, and at the same time improve the overall over-current capacity. By controlling the formula range of b · a within 8 mm - 290 mm, the overall over-current capacity can be improved.

[0120] In some embodiments, the value range of a is: 0.08 ≤ a ≤ 0.6;

[0121] And / or, the value range of b is: 80 mm ≤ b ≤ 780 mm.

[0122] Since the positive electrode tab 211 and the negative electrode tab 212 are led out from the same end of the battery cell body 22 along the first direction, and the positive electrode tab 211 and the negative electrode tab 212 carry opposite charges, by controlling the range of a within 0.08 ≤ a ≤ 0.6, on the one hand, it is beneficial to achieve the insulation effect between the positive electrode tab 211 and the negative electrode tab 212, avoiding the lap joint of the positive electrode tab 211 and the negative electrode tab 212 or the arcing of the current caused by the battery being vibrated or being in a close distance, which increases the risk of internal short circuit of the battery cell; on the other hand, it is beneficial to improve the overcurrent capacity between the positive electrode tab 211, the negative electrode tab 212 and the cover plate 11. Especially when there is a staggered layer in the tabs, it is possible to take into account the subsequent electrical connection area between the positive electrode tab 211 and the negative electrode tab 212 and the cover plate 11, improve the overcurrent capacity of the positive electrode tab 211, the negative electrode tab 212 and the cover plate, and meet the overcurrent requirements of the battery.

[0123] Optionally, the value range of a1 can be: 20mm ≤ a1 ≤ 200mm;

[0124] The value range of a2 can be: 140mm ≤ a2 ≤ 305mm.

[0125] Exemplarily, in this embodiment, the value of a can be 0.08 or 0.09 or 0.1 or 0.12 or 0.15 or 0.2 or 0.22 or 0.25 or 0.28 or 0.3 or 0.35 or 0.37 or 0.4 or 0.45 or 0.5 or 0.53 or 0.6, etc., or it can also be the interval range formed by any two of the above values.

[0126] By controlling the value range of the length b of the battery cell body 22 along the first direction within 80mm ≤ b ≤ 780mm, it is beneficial to improve the energy density of the battery and balance the overcurrent requirements of the battery at the same time.

[0127] Exemplarily, in this embodiment, the value of b can be 80mm or 100mm or 120mm or 150mm or 210mm or 230mm or 380mm or 420mm or 510mm or 580mm or 630mm or 780mm, etc., or it can also be the interval range formed by any two of the above values.

[0128] In some embodiments, the value range of the length b of the battery cell body 22 along the first direction satisfies: b ≥ 300mm; at this time, the value range of a satisfies: 0.2 ≤ a ≤ 0.6.

[0129] Combined Figure 6 and Figure 11 As shown, the end face of the laminated battery cell 2 leading out the tab 21 can specifically be the side face or the top face.

[0130] When the value range of b satisfies: b ≥ 300 mm, the end face of the tabbed battery cell 2 where the tab 21 is led out can be the side face with the smallest area among the side faces of the tabbed battery cell 2. At this time, the value range of a satisfies: 0.2 ≤ a ≤ 0.6, which is conducive to improving the current-carrying capacity between the positive tab 211, the negative tab 212 and the cover plate 11, meeting the overcurrent requirement of the battery, avoiding affecting the charging and discharging speed of the battery, preventing the occurrence of serious local heating, and reducing potential safety hazards.

[0131] In some embodiments, as shown in Figure 5 the distance between the edge of the positive tab 211 on the side away from the negative tab 212 along the second direction and the edge of the adjacent battery cell body 22 is e, satisfying: 8 mm ≤ e ≤ 50 mm;

[0132] and / or, the distance between the edge of the negative tab 212 on the side away from the positive tab 211 along the second direction and the edge of the adjacent battery cell body 22 is f, satisfying: 8 mm ≤ f ≤ 50 mm.

[0133] By controlling the distance between the positive tab 211 and the edge of the battery cell body 22 within the range of 8 mm ≤ e ≤ 50 mm, and setting the positive tab 211 close to the edge of the battery cell body 22, the settable size of the positive tab 211 is increased, the current-carrying capacity between the tab 21 and the cover plate 11 is improved, and it can also further prevent the positive tab 211 and the negative tab 212 from being set too close, especially in the case of subsequent vibration, increasing the risk of short circuit between the positive tab 211 and the negative tab 212.

[0134] Similarly, by controlling the distance between the negative tab 212 and the edge of the battery cell body 22 within the range of 8 mm ≤ f ≤ 50 mm, and setting the negative tab 212 close to the edge of the battery cell body 22, the settable size of the negative tab 212 is increased, the current-carrying capacity between the tab 21 and the cover plate 11 is improved, and it can also further prevent the positive tab 211 and the negative tab 212 from being set too close, especially in the case of subsequent vibration, increasing the risk of short circuit between the positive tab 211 and the negative tab 212.

[0135] Exemplarily, in this embodiment, the value of e can be 8 mm or 10 mm or 12 mm or 16 mm or 18 mm or 28 mm or 32 mm or 41 mm or 50 mm, etc., or it can also be the range formed by any two of the above values.

[0136] Exemplarily, in this embodiment, the value of f can be 8 mm or 10 mm or 12 mm or 16 mm or 18 mm or 28 mm or 32 mm or 41 mm or 50 mm, etc., or it can also be the range formed by any two of the above values.

[0137] In some embodiments, the value range of a satisfies: 0.15 ≤ a ≤ 0.45.

[0138] By controlling the distance e, it is possible to ensure that the distance between the edge of the positive electrode tab 211 away from the negative electrode tab 212 along the second direction is appropriate. At the same time, by precisely controlling the distance f, it is ensured that the distance between the edge of the negative electrode tab 212 away from the positive electrode tab 211 along the second direction is appropriate. On this basis, further optimizing the distance a ensures a reasonable relative position between the positive electrode tab 211 and the negative electrode tab 212, avoiding the risk of short circuit and improving the current transmission efficiency, thereby ensuring the overall performance and safety of the battery. Through the cooperation of the distance e, the distance f, and the distance a, a reasonable layout of the positive electrode tab 211 and the negative electrode tab 212 can be achieved. Ensure uniform current distribution inside the battery, reduce internal resistance, improve overall performance, and effectively prevent local overheating to ensure safe use.

[0139] Similarly, by controlling the distance g, it is possible to ensure that the distance between the edge of the positive electrode tab 211 away from the negative electrode tab 212 along the second direction is appropriate. At the same time, by precisely controlling the distance h, it is ensured that the distance between the edge of the negative electrode tab 212 away from the positive electrode tab 211 along the second direction is appropriate. On this basis, further optimizing the distance a ensures a reasonable relative position between the positive electrode tab 211 and the negative electrode tab 212, avoiding the risk of short circuit and improving the current transmission efficiency, thereby ensuring the overall performance and safety of the battery. Through the cooperation of the distance g, the distance h, and the distance a, a reasonable layout of the positive electrode tab 211 and the negative electrode tab 212 can be achieved. Ensure uniform current distribution inside the battery, reduce internal resistance, improve overall performance, and effectively prevent local overheating to ensure safe use.

[0140] In some embodiments, in combination Figure 8 As shown, along the second direction, the lead-out length j of the positive electrode tab 211 in the unfolded state satisfies: 15 mm ≤ j ≤ 45 mm;

[0141] And / or, the lead-out length k of the negative electrode tab 212 in the unfolded state satisfies: 15 mm ≤ k ≤ 45 mm.

[0142] Since the tab 21 extends from the stacked cell 2, the tab 21 is in a freely unfolded state before welding. When the tab 21 is welded and fixed, it is folded along the third direction towards the end face close to the stacked cell 2 to form a compact structure, reduce the occupied space, and ensure the orderly arrangement of the internal components of the battery.

[0143] By restricting the value range of the lead-out length j of the positive electrode tab 211 in the unfolded state to be within 15 mm ≤ j ≤ 45 mm, on the one hand, it avoids serious misalignment of the stacked battery cell 2, resulting in a small area of the positive electrode tab 211 and the negative electrode tab 212 that can be used for subsequent electrical connection, insufficient overcurrent capacity of the battery, and an increase in battery temperature rise; on the other hand, it also avoids an overly long current path between the tab 21 and the cover plate 11, resulting in an increase in overcurrent impedance and insufficient overcurrent capacity of the battery.

[0144] Exemplarily, in this embodiment, the value of j can be 15 mm or 18 mm or 19 mm or 21 mm or 25 mm or 32 mm or 38 mm or 42 mm or 45 mm, etc., or it can also be an interval range formed by any two of the above values.

[0145] Similarly, by restricting the value range of the lead-out length k of the negative electrode tab 212 in the unfolded state to be within 15 mm ≤ k ≤ 45 mm, on the one hand, it avoids serious misalignment of the stacked battery cell 2, resulting in a small area of the positive electrode tab 211 and the negative electrode tab 212 that can be used for subsequent electrical connection, insufficient overcurrent capacity of the battery; on the other hand, it also avoids an overly long current path between the tab 21 and the cover plate 11, resulting in an increase in overcurrent impedance and insufficient overcurrent capacity of the battery.

[0146] Exemplarily, in this embodiment, the value of k can be 15 mm or 18 mm or 19 mm or 21 mm or 25 mm or 32 mm or 38 mm or 42 mm or 45 mm, etc., or it can also be an interval range formed by any two of the above values.

[0147] In some embodiments, the value range of a satisfies: 0.2 ≤ a ≤ 0.5.

[0148] By controlling the length j, it can ensure the overcurrent capacity of the battery cell and avoid problems such as increased internal resistance and heat generation caused by an overly long lead-out length. At the same time, it ensures the stability of the welding area and improves the current transmission efficiency. On this basis, the value of the distance a can be further optimized to ensure an appropriate distance between the positive electrode tab 211 and the negative electrode tab 212, preventing short circuits and ensuring sufficient overcurrent capacity, thereby comprehensively improving the battery performance and safety. By precisely adjusting the value of the distance a, not only can the tab layout be optimized, but also the current distribution can be effectively balanced, energy consumption reduced, and the battery life extended.

[0149] Similarly, by controlling the length k, the overcurrent capacity of the battery cell can be ensured while avoiding the problems of increased internal resistance and heat generation caused by too long a length, and at the same time, the stability of the welding area is ensured, and the current transmission efficiency is improved. On this basis, the value of the distance a can be further optimized to ensure that the distance between the positive electrode tab 211 and the negative electrode tab 212 is appropriate, preventing short circuits and ensuring sufficient overcurrent capacity, thereby comprehensively improving the battery performance and safety. By precisely adjusting the value of the distance a, not only can the tab layout be optimized, but also the current distribution can be effectively balanced, energy consumption can be reduced, and the battery life can be extended.

[0150] In some embodiments, as shown in Figure 5 along the third direction, the positive electrode tab 211 is at least divided into two parts;

[0151] and / or, along the third direction, the negative electrode tab 212 is at least divided into two parts;

[0152] wherein, the third direction is perpendicular to the first direction and the second direction at the same time.

[0153] Since the stacked battery cell 2 includes a plurality of stacked electrode sheets 20, and each electrode sheet 20 has a tab 21 led out, the tabs 21 need to be gathered together for welding. If all the tabs are gathered together, it is easy to cause a relatively large thickness of the tabs, occupying the space of the housing and affecting the overall structural compactness of the battery cell. At the same time, if the tabs 21 are all folded to the same side, it is easy to cause a relatively large misalignment width of the folded and stacked tabs 21 along the third direction, thereby reducing the area of the effective welding area, affecting the welding quality, and reducing the overcurrent capacity of the battery cell.

[0154] By dividing the positive electrode tab 211 into at least two parts along the third direction, the thickness of a single part of the tab can be effectively reduced, the space occupied by the housing can be reduced, and the structural compactness of the battery cell can be improved. At the same time, the divided design can reduce the misalignment width after the tab is folded, increase the effective welding area, improve the welding quality, further enhance the overcurrent capacity of the battery cell, and ensure the stability and reliability of current transmission.

[0155] Similarly, by dividing the negative electrode tab 212 into at least two parts along the third direction, the thickness of a single part of the tab can be effectively reduced, the space occupied by the housing can be reduced, and the structural compactness of the battery cell can be improved. At the same time, the divided design can reduce the misalignment width after the tab is folded, increase the effective welding area, improve the welding quality, further enhance the overcurrent capacity of the battery cell, and ensure the stability and reliability of current transmission.

[0156] In some embodiments, the length of the battery cell body 22 along the first direction is greater than the length of the battery cell body 22 along the second direction, and the tab 21 extends from one end of the battery cell body 22 along the first direction; satisfying: 0.15 ≤ a ≤ 0.45.

[0157] The length of the battery cell body 22 in the first direction is greater than the length of the battery cell body 22 in the second direction. Among them, the long side of the battery cell body 22 is parallel to the first direction, and the short side of the battery cell body 22 is parallel to the second direction.

[0158] The tab 21 extends from one end of the battery cell body 22 in the first direction. That is, the tab 21 is provided on the short side of the battery cell body 22.

[0159] In some embodiments, the length of the battery cell body 22 in the second direction is greater than the length of the battery cell body 22 in the first direction, and the tab 21 extends from one end of the battery cell body 22 in the first direction; it satisfies: 0.2 ≤ a ≤ 0.6.

[0160] The length of the battery cell body 22 in the second direction is greater than the length of the battery cell body 22 in the first direction. Among them, the long side of the battery cell body 22 is parallel to the second direction, and the short side of the battery cell body 22 is parallel to the first direction.

[0161] The tab 21 extends from one end of the battery cell body 22 in the first direction. That is, the tab 21 is provided on the long side of the battery cell body 22.

[0162] When the tab 21 is provided on the short side of the battery cell body 22, the available area for a single tab 21 is small. By further limiting the range of b·a, the dimensions of the positive tab 211 and the negative tab 212 on the end face of the battery cell body 22 in the first direction can be ensured as much as possible, so as to ensure the area of the welding region and avoid affecting the current-carrying capacity.

[0163] When the tab 21 is provided on the long side of the battery cell body 22, the available area for a single tab 21 is relatively larger. By further limiting the range of b·a, the dimensions of the positive tab 211 and the negative tab 212 on the end face of the battery cell body 22 in the first direction can be ensured, so as to ensure the area of the welding region and avoid affecting the current-carrying capacity.

[0164] In some embodiments, the laminated battery cell 2 includes a plurality of stacked electrode sheets 20, and the number of layers of the electrode sheets 20 is greater than or equal to 80; and it satisfies: 0.18 ≤ a ≤ 0.5.

[0165] The number of layers of the electrode sheets 20 refers to the sum of the number of layers of the positive electrode sheets 201 and the negative electrode sheets 202. The more the number of layers of the electrode sheets 20, the greater the overall thickness of the laminated battery cell 2, and the battery cells are stacked, resulting in an increased risk of misalignment. By reasonably controlling the range of b·a, the dimensions of the tab 21 and the area of the welding region are ensured, so as to maintain the overall performance and current-carrying capacity of the laminated battery cell 2 and avoid the overcurrent problem caused by the increase in the number of layers.

[0166] In some embodiments, in combination Figure 9As shown, each pole piece 20 extends along the first direction to form a tab 21. A plurality of tabs 21 are all folded along the third direction. The dislocation width of the folded and stacked tabs 21 on one side along the third direction is m, satisfying: 0.5 mm ≤ m ≤ 5 mm;

[0167] Wherein, the third direction is perpendicular to both the first direction and the second direction.

[0168] When the dislocation width m of the folded and stacked tabs 21 along the third direction is too large, the dislocation width is relatively large, which in turn leads to a reduction in the area of the effective welding region, affects the welding quality, and reduces the over-current capacity of the battery cell.

[0169] Exemplarily, in this embodiment, the value of m can be 0.5 mm or 1 mm or 1.2 mm or 1.5 mm or 1.8 mm or 2 mm or 2.2 mm or 2.5 mm or 3.5 mm or 4 mm or 5 mm, etc., or it can also be an interval range formed by any two of the above numerical values.

[0170] In some embodiments, as shown in combination with Figure 2 both ends of the housing body 12 along the first direction are provided with openings 121;

[0171] The positive tab 211 and the negative tab 212 are respectively electrically connected to the pole posts 3 provided on the cover plate 11.

[0172] According to an embodiment of the present invention, on the other hand, a battery pack is also provided, including a plurality of batteries as described above, and further including a bottom plate, and the batteries are fixed on the bottom plate.

[0173] The batteries can be fixed on the bottom plate by means of adhesive bonding or riveting, screwing, etc.

[0174] In some embodiments, the end face of the tab 21 led out by the stacked battery cell 2 is disposed perpendicular to the surface of the bottom plate, satisfying: 14 mm ≤ b·a ≤ 350 mm.

[0175] When the end face of the tab 21 led out by the stacked battery cell 2 is disposed perpendicular to the surface of the bottom plate, when the battery pack vibrates as a whole, the tab 21 is subjected to a large force, which easily causes the positive and negative tabs to overlap. By controlling the formula range of b·a within 14 mm ≤ b·a ≤ 350 mm, the risk of internal short circuit of the battery caused by the overlap of the positive and negative tabs is avoided. Increasing b is beneficial to increasing the contact area between the housing 1 and the bottom plate and improving the connection strength between the two. Increasing a enables the distance between the positive and negative tabs to be controllable.

[0176] In some embodiments, the end face of the tab 21 led out by the stacked battery cell 2 is disposed parallel to the surface of the bottom plate, satisfying: 10 mm ≤ b·a ≤ 300 mm.

[0177] The end face of the tab 21 led out from the stacked cell 2 is arranged parallel to the surface of the bottom plate, that is, the end face of the tab 21 led out from the stacked cell 2 is located on the bottom surface or the top surface of the stacked cell 2. In this case, during the vibration of the battery pack, the vibration of the positive and negative tabs results in a relatively small risk of tab overlap. Therefore, by controlling the formula range of b·a within 10 mm ≤ b·a ≤ 300 mm, the overall over-current rate of the battery is increased.

[0178] In some embodiments, the end face of the tab 21 led out from the stacked cell 2 faces away from the bottom plate and satisfies: 8 mm ≤ b·a ≤ 280 mm.

[0179] The end face of the tab 21 led out from the stacked cell 2 faces away from the bottom plate, that is, the end face of the tab 21 led out from the stacked cell 2 is located on the bottom surface or the top surface of the stacked cell 2. In this case, during the vibration of the battery pack, the vibration of the positive and negative tabs results in a relatively small risk of tab overlap. Therefore, by controlling the formula range of b·a within 8 mm ≤ b·a ≤ 280 mm, the overall over-current rate of the battery is increased.

[0180] Obviously, the above embodiments are only examples clearly described and not limitations on the implementation manners. Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the present invention.

Claims

1. A battery, characterized in that, Comprising: A housing (1); A terminal post (3) disposed on the housing (1); A stacked battery cell (2) disposed within the housing (1), the stacked battery cell (2) including a cell body (22) and tabs (21) extending from one end of the cell body (22) in a first direction; the tabs (21) being adapted to be electrically connected to the terminal post (3); The tabs (21) include a positive tab (211) and a negative tab (212), both the positive tab (211) and the negative tab (212) being located at the same end of the cell body (22) in the first direction; and the positive tab (211) and the negative tab (212) being spaced apart in a second direction, wherein the second direction is perpendicular to the first direction; The spacing distance between the positive tab (211) and the negative tab (212) in the second direction is a1, and the width of the stacked battery cell (2) in the second direction is a2, satisfying a = a1 / a2; the length of the cell body (22) in the first direction is b, in millimeters; satisfying: 8 mm ≤ b·a ≤ 350 mm.

2. The battery according to claim 1, characterized in that, The housing (1) includes a housing body (12) and a cover plate (11), at least one end of the housing body (12) in the first direction being provided with an opening (121), and the cover plate (11) being disposed to block the opening (121); The battery further includes a terminal post assembly disposed on the cover plate (11), and the tabs (21) being led out towards the cover plate (11); satisfying: 8 mm ≤ b·a ≤ 300 mm.

3. The battery according to claim 1, characterized in that, The stacked battery cell (2) includes a positive electrode plate (201) and a negative electrode plate (202); the negative electrode plate (202) extending beyond the positive electrode plate (201) in the first direction, satisfying: 12 mm ≤ b·a ≤ 350 mm.

4. The battery according to claim 3, wherein, The dimension by which the negative electrode plate (202) extends beyond the positive electrode plate (201) in the first direction is p, satisfying 1 mm ≤ p ≤ 3 mm.

5. The battery according to claim 1, wherein, The stacked battery cell (2) includes a plurality of stacked electrode plates (20), the electrode plates (20) including an electrode plate body (23) and the tabs (21) led out from the electrode plate body (23), and the electrode plate body (23) being provided with a convex portion (24) protruding towards the large surface direction perpendicular to the electrode plate body (23), satisfying: 10 mm ≤ b·a ≤ 320 mm.

6. The battery according to claim 5, characterized in that, The convex portion (24) includes a plurality of them, and the plurality of convex portions (24) are spaced apart in the second direction.

7. The battery according to claim 5, characterized in that, The height by which the convex portion protrudes in the direction perpendicular to the large surface of the electrode plate body (23) is q, satisfying 0.5 mm ≤ q ≤ 2 mm.

8. The battery according to claim 1, characterized in that, The battery further includes: a connecting piece (4), the connecting piece (4) being electrically connected between the tabs (21) and the terminal post (3), and a part of the tabs (21) being disposed on the surface of the connecting piece (4) facing away from the stacked battery cell (2); satisfying: 8 mm ≤ b·a ≤ 290 mm.

9. The battery according to claim 1, characterized in that, The value range of a is: 0.08 ≤ a ≤ 0.6; And / or, the value range of b is: 80 mm ≤ b ≤ 780 mm.

10. The battery according to claim 1, wherein, The value range of the length b of the battery cell body (22) along the first direction satisfies: b ≥ 300 mm; at this time, the value range of a satisfies: 0.2 ≤ a ≤ 0.

6.

11. The battery according to claim 1, characterized in that, The distance between the edge of the positive electrode tab (211) on the side away from the negative electrode tab (212) along the second direction and the edge of the adjacent battery cell body (22) is e, satisfying: 8 mm ≤ e ≤ 50 mm; And / or, the distance between the edge of the negative electrode tab (212) on the side away from the positive electrode tab (211) along the second direction and the edge of the adjacent battery cell body (22) is f, satisfying: 8 mm ≤ f ≤ 50 mm.

12. The battery according to claim 11, wherein, The value range of a satisfies: 0.15 ≤ a ≤ 0.

45.

13. The battery according to claim 1, characterized in that, Along the second direction, the lead-out length j of the positive electrode tab (211) in the unfolded state satisfies: 15 mm ≤ j ≤ 45 mm; And / or, the lead-out length k of the negative electrode tab (212) in the unfolded state satisfies: 15 mm ≤ k ≤ 45 mm.

14. The battery according to claim 13, wherein The value range of a satisfies: 0.2 ≤ a ≤ 0.

5.

15. The battery according to claim 1, characterized in that, Along the third direction, the positive electrode tab (211) is at least divided into two parts; And / or, along the third direction, the negative electrode tab (212) is at least divided into two parts; Wherein, the third direction is perpendicular to both the first direction and the second direction at the same time.

16. The battery according to claim 1, characterized in that, The length of the battery cell body (22) along the first direction is greater than the length of the battery cell body (22) along the second direction, and the tab (21) extends from one end of the battery cell body (22) along the first direction; Satisfying: 0.15 ≤ a ≤ 0.

45.

17. The battery according to claim 1, characterized in that, The length of the battery cell body (22) along the second direction is greater than the length of the battery cell body (22) along the first direction, and the tab (21) extends from one end of the battery cell body (22) along the first direction; Satisfying: 0.2 ≤ a ≤ 0.

6.

18. The battery according to claim 1, characterized in that, The laminated battery cell (2) includes a plurality of stacked electrode sheets (20), the number of layers of the electrode sheets (20) is greater than or equal to 80; and satisfying: 0.18 ≤ a ≤ 0.

5.

19. The battery according to claim 18, wherein Each electrode sheet (20) is formed with a tab (21) extending along the first direction, and a plurality of the tabs (21) are all folded along the third direction. The misalignment width m of the folded and stacked tabs (21) on one side along the third direction satisfies: 0.5 mm ≤ m ≤ 5 mm; Wherein, the third direction is perpendicular to both the first direction and the second direction at the same time.

20. The battery according to claim 2, characterized in that, Both ends of the shell body (12) along the first direction are provided with openings (121); The positive electrode tab (211) and the negative electrode tab (212) are respectively electrically connected to the electrode posts (3) provided on the cover plate (11).

21. A battery pack, characterized in that, Including a plurality of batteries as described in any one of the above claims 1 to 20, further including a bottom plate, and the batteries are fixed on the bottom plate.

22. The battery pack according to claim 21, characterized in that, The end face of the stacked cell (2) from which the tab (21) is led out is arranged perpendicular to the surface of the bottom plate, satisfying: 14 mm ≤ b·a ≤ 350 mm.

23. The battery pack according to claim 21, wherein, The end face of the stacked cell (2) from which the tab (21) is led out is arranged parallel to the surface of the bottom plate, satisfying: 10 mm ≤ b·a ≤ 300 mm.

24. The battery pack according to claim 21, characterized in that, The end face of the stacked cell (2) from which the tab (21) is led out is arranged away from the bottom plate, satisfying: 8 mm ≤ b·a ≤ 280 mm.

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