Battery and battery pack

Abstract

The application relates to the technical field of new energy, and discloses a battery and a battery pack, the battery comprising: a shell; a pole; a laminated battery cell comprising a battery cell body and a tab extending out from one end of the battery cell body along a first direction; the tab is electrically connected with the pole; the tab comprises a positive tab and a negative tab, and the positive tab and the negative tab are located at the same end of the battery cell body along the first direction; and the positive tab and the negative tab are arranged at intervals along a second direction, wherein the second direction is perpendicular to the first direction; the interval distance of the positive tab and the negative tab along the second direction is a1, the width of the laminated battery cell along the second direction is a2, a=a1 / a2 is satisfied, the length of the battery cell body along the first direction is b, and 8mm<=b*x*a<=350mm is satisfied. The battery provided by the application is large in b*x*a, is prone to increase the overcurrent demand of the battery cell, and is prone to reduce the area of a welding region. The battery energy density is low when b*x*a is small.

Description

Technical Field

[0001] This invention relates to the field of new energy technology, specifically to a battery and battery pack. Background Technology

[0002] A laminated battery cell is a type of battery cell manufactured using a lamination process. Multiple single electrode sheets are stacked together to form a laminated battery cell. Laminated battery cells typically consist of a positive electrode, a separator, and a negative electrode. Laminated battery cells improve the overall space utilization within a prismatic battery and avoid risks such as lithium plating at the electrode ends.

[0003] However, during the stacking process, the end alignment between the electrodes is poor, which poses a risk of misalignment between the electrodes. This reduces the overall current-carrying area of ​​the tabs and thus affects the current-carrying capacity of the stacked cells. 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 overcurrent capacity of stacked battery cells.

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

[0006] case;

[0007] The pole is located in the housing;

[0008] A laminated battery cell is disposed within a housing. The laminated battery cell includes a cell body and a tab extending from one end of the cell body along a first direction. The tab is adapted to be electrically connected to a terminal post.

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

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

[0011] Beneficial effects: By comprehensively controlling a and b, if the formula value is too large, it can easily affect the subsequent electrical connection between the positive and negative electrode tabs and the cover plate, resulting in insufficient overcurrent capacity of the cover plate and the positive and negative electrode tabs, which in turn leads to insufficient battery overcurrent capacity, easily causing increased battery temperature rise and affecting battery safety; if the formula value is too small, the positive and negative electrode tabs are easily affected by vibration or are too close, which can cause bridging or current arcing, leading to the risk of internal short circuit in the battery.

[0012] Secondly, the present invention also provides a battery pack, including a plurality of batteries as described above, and a base plate on which the batteries are fixed.

[0013] Since the battery pack includes batteries and has the same effect as batteries, it will not be elaborated on here. Attached Figure Description

[0014] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the battery of the present invention;

[0016] Figure 2 This is a schematic diagram showing the disassembled state of the battery of the present invention;

[0017] Figure 3 This is a partially enlarged view of the battery of the present invention in a decomposed state;

[0018] Figure 4 This is a partially enlarged view of the battery cell of the present invention;

[0019] Figure 5 This is a side view of the battery cell of the present invention;

[0020] Figure 6 for Figure 5 Schematic diagram of section AA;

[0021] Figure 7 This is a schematic diagram of the stacked state of the positive and negative electrode sheets of the present invention;

[0022] Figure 8 This is a cross-sectional view of the battery cell when the tabs of the present invention are in the unfolded state;

[0023] Figure 9 for Figure 4 Schematic diagram of the BB section;

[0024] Figure 10 This is a side view of the electrode sheet of the present invention;

[0025] Figure 11 This is a cross-sectional schematic diagram of another type of battery cell according to the present invention.

[0026] Explanation of reference numerals in the attached figures:

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

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

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

[0030] 3. Pole post. Detailed Implementation

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

[0032] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0034] Furthermore, 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] A laminated battery cell is a type of battery cell manufactured using a lamination process. Multiple individual electrode sheets are stacked together to form a laminated battery cell. A laminated battery cell typically consists of a positive electrode, a separator, and a negative electrode. While the multiple layers of positive and negative electrode sheets are separate, the areas of the positive electrode, separator, and negative electrode sheets differ, and adjacent layers of positive or negative electrode sheets are discontinuous. Therefore, after lamination, it is difficult to ensure that the projections of electrodes of the same polarity completely overlap. Meanwhile, since individual electrode sheets extend to form tabs, during the stacking process of laminated cells, the alignment of the edges of electrodes of the same polarity is poor, causing misalignment of the electrodes. This leads to a shift in the position of the tabs, affecting the current-carrying area of ​​the overall tabs and the electrical connection of the terminal assembly, and affecting the overall charge and discharge rate of the battery. This can easily cause a large temperature rise in the battery, affecting battery safety. Research has found that when the positive and negative tabs are located on the same side of the laminated cell, the problem of tab misalignment is particularly serious. Due to the misalignment between the positive and negative tabs, there is a risk of internal short circuits caused by the overlap of the positive and negative tabs.

[0036] During subsequent welding, the welding area needs to be located in the area where multiple layers of tabs completely overlap to ensure that all electrodes can conduct electricity. When the tabs are severely misaligned, the non-overlapping areas cannot be used as welding areas to avoid one or more tabs being left unwelded. This results in a limited welding area when the tabs are severely misaligned, leading to a reduction in the welding area, which in turn reduces the cell's current carrying capacity, affects the battery's charging and discharging speed, and may even cause severe localized overheating, posing a significant safety hazard.

[0037] The following is combined with Figures 1 to 11 The following describes embodiments of the present invention.

[0038] According to an embodiment of the present invention, in one aspect, a battery is provided, comprising:

[0039] Casing 1;

[0040] The pole post 3 is disposed on the housing 1;

[0041] The laminated battery cell 2 is disposed inside the housing 1. The laminated battery cell 2 includes a battery cell body 22 and a tab 21 extending from one end of the battery cell body 22 along a first direction; the tab 21 is adapted to be electrically connected to the terminal post 3.

[0042] The electrode 21 includes a positive electrode 211 and a negative electrode 212, both of which are located at the same end of the cell body 22 along the first direction; and the positive electrode 211 and the negative electrode 212 are spaced apart along the second direction, wherein the second direction is perpendicular to the first direction.

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

[0044] The battery in this embodiment can be a prismatic battery, a blade battery, etc. Specifically, the laminated cell 2 can be a cell manufactured using a lamination 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, and the second direction can be the direction perpendicular to the surface of the lead-out tab 21 of the stacked cell 2. The third direction can be the thickness direction of the cell body 22.

[0046] a2 refers to the width of the laminated cell 2 along the second direction. In this embodiment, it can specifically be the dimension of the end face of the laminated cell 2 with tab 21 along the second direction.

[0047] Combination Figure 6 and Figure 11 As shown, the end face of the lead tab 21 of the laminated cell 2 can be either the side or the top surface.

[0048] As an optional implementation, combined with Figure 4 As shown, the positive electrode tab 211 can be divided into two parts along a third direction. Both parts of the tab are folded towards the middle area, which facilitates the parallel connection of the two parts of the tab. Then, they are electrically connected to the cover plate, which reduces the current transmission impedance of the tab and helps to improve 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 may 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 pole 3 can include: aluminum, aluminum alloy, copper-aluminum composite, nickel and other metal materials.

[0051] The laminated cell 2 is formed by stacking a positive electrode 201, a negative electrode 202 and a separator disposed between them 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 made of metal materials such as aluminum foil, nickel foil, and stainless steel, or a composite foil material formed by combining metals and insulating materials. The positive electrode active material includes a main positive electrode material, a conductive agent, a binder, etc. The main positive electrode material includes one or more lithium-containing positive electrode active materials such as lithium iron phosphate, ternary materials containing nickel, cobalt, and manganese, and lithium manganese iron phosphate.

[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, and stainless steel, or it can be a composite foil material formed by combining metals and insulating materials. The negative electrode active material includes a negative electrode active main material, a conductive agent, and a binder. The negative electrode active main material includes one or more of the following: artificial graphite, natural graphite, silicon carbide, silicon oxide, and lithium titanate.

[0054] The laminated cell 2 extends into a tab 21, which is suitable for electrical connection with the terminal post 3. The tab 21 serves as the output end of the laminated cell 2, and the terminal post 3 serves as the output end of the battery. The tab 21 can be electrically connected to the terminal post 3 by welding with an adapter piece, or it can be directly welded to the terminal post 3. Welding can be performed by ultrasonic welding, resistance welding, or laser welding.

[0055] Since the positive electrode tab 211 and the negative electrode tab 212 are led out from both ends of the cell body 22 along the first direction, the battery needs to reserve space for arranging the tabs at both ends of the casing 1 along the first direction, which can easily lead to a decrease in the space utilization rate of the battery. In this embodiment, the positive electrode tab 211 and the negative electrode tab 212 are both led out from the same end of the cell body 22 along the first direction, so the battery only needs to reserve space for arranging the tabs at one end of the casing 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, the positive electrode tab 211 and the negative electrode tab 212 are spaced apart along the second direction to prevent the positive and negative electrodes from overlapping. However, the electrode sheets of the stacked cell are separate. Therefore, under certain operating conditions or when the stacking alignment is poor, the positive and negative electrodes are easily subjected to vibration or are too close, which may cause overlapping or arcing of current, leading to the risk of internal short circuit in the battery.

[0057] However, due to the limited area of ​​the end face of the cell body 22, 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 size of the positive electrode tab 211 and the negative electrode tab 212 is easily restricted, which in turn affects the overcurrent capacity of the stacked cell 2. In this embodiment, by further constraining 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 overcurrent capacity of the battery is enhanced, and the overlap between the positive electrode tab 211 and the negative electrode tab 212 is avoided, especially when subjected to vibration or close proximity, to prevent current arcing, prevent internal short circuit of the battery, and improve the overcurrent capacity of the stacked cell 2.

[0058] By comprehensively controlling a and b, if the formula value is too large, it can easily affect the subsequent electrical connection between the positive electrode tab 211 and the negative electrode tab 212 and the cover plate, resulting in insufficient overcurrent capacity of the cover plate and the positive electrode tab 211 and the negative electrode tab 212, thus causing insufficient overcurrent capacity of the battery. If the formula value is too small, the positive electrode tab 211 and the negative electrode tab 212 are easily affected by vibration or are too close, which may cause bridging or arcing of current, leading to the risk of internal short circuit in the battery.

[0059] Referring to Table 1 below, the overcurrent capability and internal short-circuit risk of the provided battery were tested through several embodiments and comparative tests.

[0060]

[0061] Examples 1-14 and Comparative Examples 1-2 used ternary cathodes. Examples 15-17 and Comparative Examples 3-4 used lithium iron phosphate (LFP) cathodes.

[0062] First, the specific preparation methods for the batteries used in Examples 1-14 and Comparative Examples 1-2 are as follows:

[0063] (1) Preparation of the positive electrode:

[0064] The prepared positive electrode active material LiNi 0.6 Co 0.2 Mn 0.2 O2, conductive agent acetylene black, and binder PVDF are mixed in a mass ratio of 95:3:2. NMP solvent is added, and the mixture is stirred in a vacuum mixer until the system is homogeneous to obtain a positive electrode slurry. The positive electrode slurry is uniformly coated on both surfaces of the positive electrode current collector aluminum foil, dried at room temperature, and then transferred to an oven for further drying. After cold pressing and slitting, the positive electrode sheet is obtained.

[0065] (2) Preparation of negative electrode:

[0066] The negative electrode active material graphite, conductive agent acetylene black, thickener CMC, and binder SBR are mixed in a mass ratio of 96:1:1.5:1.5. Deionized water is added as a solvent, and the mixture is stirred under vacuum until the system is homogeneous to obtain a negative electrode slurry. The negative electrode slurry is uniformly coated on both surfaces of the negative electrode current collector copper foil, dried at room temperature, and then transferred to an oven for further drying. After cold pressing and slitting, the negative electrode sheet is obtained.

[0067] (3) Preparation of electrolyte:

[0068] 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, fully dried lithium salt LiPF6 was dissolved in the mixed organic solvent to prepare an electrolyte with a concentration of 1 mol / L.

[0069] Preparation of the diaphragm:

[0070] Polyethylene film is selected as the diaphragm.

[0071] (5) Preparation of lithium-ion batteries:

[0072] The positive electrode, separator, and negative electrode are prepared in sequence through a stacking process, with the separator positioned between the positive and negative electrodes to act as an separator. After the battery cell is prepared, the bare battery cell is inserted into the casing through the opening 121 of the casing body 12. The cover plate 11 and the casing body 12 are laser-sealed and welded. After drying, electrolyte is injected, and the battery is obtained through vacuum sealing, settling, formation, and shaping processes.

[0073] In Examples 15-17 and Comparative Examples 3-4, the cathode material was changed to lithium iron phosphate, while the rest remained unchanged.

[0074] Performance Test 1:

[0075] Internal short-circuit testing can detect whether the battery is at risk of short circuit. The specific test method is as follows:

[0076] Vibration tests were performed on the bare cells obtained in Examples 1-15 and Comparative Examples 1-4, as described below. Simultaneously, voltage tests were performed by connecting the circuit. The positive and negative tabs of the bare cells were connected to electrodes, and the voltage between the positive and negative tabs was measured. For the positive electrode active material LiNi... 0.6 Co 0.2 Mn 0.2 If the voltage between the positive and negative electrodes of a battery cell obtained from O2 is between 4.2-4.3V, it indicates that the voltage between the positive and negative electrodes is normal; if the voltage between the positive and negative electrodes is between 3.8V-4.2V (less than), it indicates a minor short circuit; if the voltage between the positive and negative electrodes is less than 1V, it indicates a short circuit between the positive and negative electrodes.

[0077] For lithium iron phosphate batteries, if the voltage between the positive and negative electrodes is measured to be between 3.5 and 3.7V, it indicates that the voltage between the positive and negative electrodes is normal; if the voltage between the positive and negative electrodes is measured to be between 3.0V and 3.5V, it indicates a minor short circuit; if the voltage between the positive and negative electrodes is less than 1V, it indicates that a short circuit has occurred between the positive and negative electrodes.

[0078] For the above tests, 5 samples were tested in parallel in each group.

[0079] Vibration testing method: Vibration parameters shall be tested according to the following requirements.

[0080] The battery cell was mounted on a vibration table and subjected to up-and-down vibration at a frequency of 10Hz-55Hz and a maximum acceleration of 30m / s². 2 Vibration time: 3 hours.

[0081] Performance Test 2:

[0082] Terminal temperature rise testing measures the battery's overcurrent capability. The cover plate contains terminals, and the battery temperature rise is tested using the following method:

[0083] 1) For lithium iron phosphate batteries: charge at a constant current rate of 3C to 3.65V, and then charge at a constant voltage until the current drops to 0.05C; connect a temperature sensor to the terminal to sample the temperature of the terminal during the charging process;

[0084] 2) For the positive electrode active material LiNi 0.6 Co 0.2 Mn 0.2 The O2 battery is charged at a constant current rate of 3C to 4.25V, and then charged at a constant voltage until the current drops to 0.05C; a temperature sensor is connected to the terminal to sample the temperature of the terminal during the charging process.

[0085] The temperature of the electrode is sampled to obtain the highest temperature T in the electrode region. If the highest temperature T in the electrode region is ≤ 45℃, it is considered good; if 45℃ < T ≤ 65℃, it is considered qualified; and if T > 65℃, it is considered unqualified.

[0086] For the above tests, 5 samples were tested in parallel in each group.

[0087] Based on Table 1 above, the explanation is as follows:

[0088] In Examples 1-11, the value of b×a satisfies: 8mm≤b×a≤350mm. Performance Test 1 shows normal voltage between the positive and negative electrodes, and no short circuits were detected in the internal short-circuit tests, meeting the performance requirements. Performance Test 2 shows that the temperature rise of the electrode posts is less than or equal to 45℃, indicating good temperature control and meeting the performance requirements.

[0089] In Example 12, the value of b×a satisfies: 8mm≤b×a≤350mm. However, due to the small value of a, the voltage between the positive and negative electrodes is too low according to performance test one, which is prone to micro-short circuits and poses a certain safety hazard. According to performance test two, the temperature rise of the electrode posts is less than or equal to 45℃, the temperature control is good, and the performance requirements are met.

[0090] In Example 13, the value of b×a satisfies: 8mm≤b×a≤350mm. However, due to the relatively large value of a, performance test one showed that the voltage between the positive and negative electrodes was normal, and no short circuit occurred during internal short circuit tests, thus meeting the performance requirements. Performance test two showed that the temperature rise was greater than 45℃ and less than or equal to 65℃, indicating that the temperature control was qualified and the performance requirements were basically met.

[0091] In Example 14, the value of b×a satisfies: 8mm≤b×a≤350mm. However, because the value of a is too small and the value of b is too large, the voltage between the positive and negative electrodes is too low according to performance test one, which is prone to micro-short circuits and poses a certain safety hazard. According to performance test two, the temperature rise is greater than 45℃ and less than or equal to 65℃, the temperature control is qualified, and the performance requirements are basically met.

[0092] In Comparative Example 1, the value of b×a is less than the lower limit of the formula. Performance Test 1 shows that the voltage between the positive and negative electrodes is less than 1V, which is abnormal and prone to short circuits, posing a significant safety hazard. Performance Test 2 shows that the temperature rise is greater than 65℃, indicating unqualified temperature control and failure to meet performance requirements.

[0093] In Comparative Example 2, the value of b×a is greater than the upper limit of the formula. Performance Test 1 shows that the voltage between the positive and negative electrodes is normal, and no short circuit occurred during the internal short-circuit test, thus meeting the performance requirements. However, Performance Test 2 shows that the temperature rise exceeds 65℃, indicating that temperature control is unqualified and the performance requirements cannot be met.

[0094] In Example 15, the value of b×a satisfies: 8mm≤b×a≤350mm. Performance Test 1 shows normal voltage between the positive and negative electrodes, and no short circuits were detected in the internal short-circuit tests, meeting the performance requirements. Performance Test 2 shows that the temperature rise of the electrode posts is less than or equal to 45℃, indicating good temperature control and meeting the performance requirements.

[0095] In Example 16, the value of b×a satisfies: 8mm≤b×a≤350mm. However, due to the relatively large value of a, performance test one showed that the voltage between the positive and negative electrodes was normal, and no short circuit occurred during internal short circuit tests, thus meeting the performance requirements. Performance test two showed that the temperature rise was greater than 45℃ and less than or equal to 65℃, indicating that the temperature control was qualified and the performance requirements were basically met.

[0096] In Example 17, the value of b×a satisfies: 8mm≤b×a≤350mm. However, because the value of a is too small and the value of b is too large, the voltage between the positive and negative electrodes is too low according to performance test one, which is prone to micro-short circuits and poses a certain safety hazard. According to performance test two, the temperature rise is greater than 45℃ and less than or equal to 65℃, the temperature control is qualified, and the performance requirements are basically met.

[0097] In Comparative Example 3, the value of b×a is less than the lower limit of the formula. Performance Test 1 shows that the voltage between the positive and negative electrodes is less than 1V, which is abnormal and prone to short circuits, posing a significant safety hazard. Performance Test 2 shows that the temperature rise is greater than 65℃, indicating unqualified temperature control and failure to meet performance requirements.

[0098] In Comparative Example 4, the value of b×a is greater than the upper limit of the formula. Performance Test 1 shows that the voltage between the positive and negative electrodes is normal, and no short circuit occurred during the internal short-circuit test, thus meeting the performance requirements. However, Performance Test 2 shows that the temperature rise exceeds 65℃, indicating that temperature control is unqualified and the performance requirements cannot be met.

[0099] For example, 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, or it can be any range formed by any two of the above values.

[0100] By setting the value of b×a appropriately, on the one hand, the electrical connection area between the positive electrode tab 211 and the negative electrode tab 212 and the cover plate can be guaranteed, thus ensuring the overcurrent capacity of the battery cell; on the other hand, the risk of short circuit due to tab short connection can be reduced.

[0101] In some embodiments, the housing 1 includes a housing body 12 and a cover plate 11. The housing body 12 is provided with an opening 121 at at least one end along a first direction, and the cover plate 11 is provided to block the opening 121.

[0102] The battery also includes a terminal assembly, which is disposed on the cover plate 11, with the tabs 21 extending out toward the cover plate 11; satisfying: 8mm≤b×a≤300mm.

[0103] It should be noted that the pole assembly may include pole 3 and / or adapter plate. The tab 21 may be directly welded to pole 3 to achieve electrical connection; or, the tab 21 may also be welded to adapter plate, using the adapter plate as an intermediary to achieve electrical connection with pole 3.

[0104] The structure adopted in this embodiment involves opening an opening 121 in the shell body 12 and sealing the opening 121 with a cover plate 11. A terminal post assembly is then installed on the cover plate 11, with the tab 21 extending towards the cover plate 11. This facilitates the assembly of the tab 21 and the terminal post 3, preventing situations where the tab 21 and terminal post assembly are difficult to align and connect accurately due to misalignment of the electrode sheet 20. This improves the overall battery assembly efficiency and enhances overcurrent transmission capability. The formula range of b×a is controlled within 8mm-300mm, reducing the risk of internal short circuits between the positive and negative electrode tabs.

[0105] In some embodiments, the laminated cell 2 includes a positive electrode 201 and a negative electrode 202; the negative electrode 202 is disposed beyond the positive electrode 201 along a first direction, satisfying: 12mm≤b×a≤350mm.

[0106] Exacerbating the risk of misalignment and affecting overcurrent, by controlling the formula range of b×a within 12mm-350mm, it is possible to avoid a decrease in overcurrent and prevent an increase in battery temperature rise.

[0107] The negative electrode 202 extends beyond the positive electrode 201 along the first direction, which can prevent lithium ions extracted from the positive electrode from reaching the negative electrode and causing lithium plating due to insufficient lithium intercalation space. However, the way the negative electrode 202 extends beyond the positive electrode 201 also results in poorer alignment of the electrode stack ends, causing the electrode 20 to drive the tab 21 to mis-layer, exacerbating the risk of mis-layering, affecting the overall welding area of ​​the tab 21, affecting overcurrent, and consequently leading to poor current transmission rate of the tab 21. This results in severe heat generation inside the stacked cell 2. By controlling the formula range of b×a within 12mm-350mm, it is possible to avoid a decrease in overcurrent, prevent an increase in battery temperature rise, and improve the battery charging rate.

[0108] In some embodiments, combined with Figure 7 As shown, the negative electrode 202 extends beyond the positive electrode 201 by a dimension p along the first direction, satisfying 1mm≤p≤3mm.

[0109] For example, in this embodiment, the value of p can be 1mm or 1.1mm or 1.2mm or 1.5mm or 1.8mm or 2mm or 2.6mm or 2.9mm or 3mm, or it can be any range formed by any two of the above values.

[0110] In some embodiments, combined with Figure 10 As shown, the laminated cell 2 includes multiple stacked electrodes 20. Each electrode 20 includes an electrode body 23 and a tab 21 extending from the electrode body 23. The electrode body 23 is provided with a protrusion 24 protruding in the direction perpendicular to the large surface of the electrode body 23, satisfying: 10mm≤b×a≤320mm.

[0111] The electrode body 23 is provided with a protrusion 24 protruding in the direction of the large surface perpendicular to the electrode body 23, which can increase the friction between the electrodes 20, thereby reducing the relative movement between multiple tabs 21 during the handling process to a certain extent, reducing the risk of short circuit between positive and negative tabs, enabling adjacent electrodes to form a good positioning, mitigating the impact of electrode misalignment, and by controlling the formula range of b×a within 10mm-320mm, it is possible to avoid overlapping of adjacent positive and negative electrodes.

[0112] In some embodiments, the protrusions 24 include a plurality of protrusions 24, which are spaced apart along a second direction.

[0113] By setting multiple protrusions 24, the positioning effect between adjacent electrodes can be improved, further mitigating the impact of electrode misalignment.

[0114] In some embodiments, the height of the protrusion in the direction of the large surface of the vertical electrode body 23 is q, which satisfies 0.5mm≤q≤2mm.

[0115] If the protrusion is too low, the force increasing friction will be weak, failing to reduce the relative movement of the tabs and thus failing to reduce the risk of short circuits between the positive and negative electrodes. Conversely, the protrusion should not be too high to avoid affecting the transport of lithium ions between the positive and negative electrodes.

[0116] For example, in this embodiment, the value of q can be 0.5mm or 0.6mm or 0.8mm or 1mm or 1.2mm or 1.5mm or 1.8mm or 2mm, or it can be a range formed by any two of the above values.

[0117] In some embodiments, the battery further includes: an adapter piece, which is electrically connected between the tab 21 and the post 3, with the tab 21 partially disposed on the surface of the adapter piece away from the stacked cell 2; satisfying: 8mm≤b×a≤290mm.

[0118] The tab 21 is positioned on the surface of the adapter plate away from the stacked cell 2, which improves the overall space utilization inside the battery, shortens the current transmission path between the tab 21 and the terminal 3, and enhances the overall overcurrent capacity. By controlling the formula range of b×a within 8mm-290mm, the overall overcurrent capacity can be further improved.

[0119] In some embodiments, the value range of a is: 0.08≤a≤0.6;

[0120] And / or, the value range of b is: 80mm≤b≤780mm.

[0121] 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, 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 positive electrode tab 211 and the negative electrode tab 212 from bridging or arcing due to vibration of the battery or close proximity, which would increase the risk of short circuit inside the 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 misalignment of the tabs, it can take into account the electrical connection area between the positive electrode tab 211 and the negative electrode tab 212 and the cover plate 11, improve the overcurrent capacity between the positive electrode tab 211 and the negative electrode tab 212 and the cover plate, and meet the overcurrent requirements of the battery.

[0122] Optionally, the value range of a1 can be: 20mm≤a1≤200mm;

[0123] The range of values ​​for a2 is: 140mm≤a2≤305mm.

[0124] For example, 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, or it can be any range formed by any two of the above values.

[0125] By controlling the length b of the cell body 22 along the first direction to be within the range of 80mm≤b≤780mm, it is beneficial to improve the energy density of the battery and balance the overcurrent demand of the battery.

[0126] For example, 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, or it can be any range formed by any two of the above values.

[0127] In some embodiments, the length b of the cell body 22 along the first direction is within the range of b ≥ 300 mm; at this time, the value range of a is within the range of 0.2 ≤ a ≤ 0.6.

[0128] Combination Figure 6 and Figure 11 As shown, the end face of the lead tab 21 of the laminated cell 2 can be either the side or the top surface.

[0129] When the value of b satisfies b≥300mm, the end face of the lead tab 21 of the stacked cell 2 can be the side with the smallest area among all sides of the stacked cell 2. At this time, the value of a satisfies 0.2≤a≤0.6, which helps to improve the overcurrent capacity between the positive electrode tab 211, the negative electrode tab 212 and the cover plate 11, meet the overcurrent requirements of the battery, avoid affecting the charging and discharging speed of the battery, prevent the occurrence of severe local heat generation, and reduce safety hazards.

[0130] In some embodiments, combined with Figure 5 As shown, the edge of the positive electrode tab 211 away from the negative electrode tab 212 along the second direction is e from the edge of the adjacent cell body 22, which satisfies: 8mm≤e≤50mm;

[0131] And / or, the edge of the negative electrode tab 212 away from the positive electrode tab 211 along the second direction is a distance f from the edge of the adjacent cell body 22, satisfying: 8mm≤f≤50mm.

[0132] By controlling the distance between the positive electrode tab 211 and the edge of the cell body 22 to be within the range of 8mm≤e≤50mm, the positive electrode tab 211 is placed close to the edge of the cell body 22, which increases the size that the positive electrode tab 211 can be set to, improves the current carrying capacity between the tab 21 and the cover plate 11, and can also further avoid the positive electrode tab 211 and the negative electrode tab 212 being placed too close together, especially when subjected to vibration, which would increase the risk of short circuit between the positive electrode tab 211 and the negative electrode tab 212.

[0133] Similarly, by controlling the distance between the negative electrode tab 212 and the edge of the cell body 22 to be within the range of 8mm≤f≤50mm, the negative electrode tab 212 is placed close to the edge of the cell body 22, which increases the size that the negative electrode tab 212 can be set up, improves the current carrying capacity between the tab 21 and the cover plate 11, and can also further avoid the positive electrode tab 211 and the negative electrode tab 212 being too close together, especially when subjected to vibration, which would increase the risk of short circuit between the positive electrode tab 211 and the negative electrode tab 212.

[0134] For example, in this embodiment, the value of e can be 8mm or 10mm or 12mm or 16mm or 18mm or 28mm or 32mm or 41mm or 50mm, or it can be a range formed by any two of the above values.

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

[0136] In some embodiments, the value range of a satisfies: 0.15≤a≤0.45.

[0137] By controlling distance e, the distance of the edge of the positive electrode tab 211 away from the negative electrode tab 212 along the second direction can be ensured to be moderate. Simultaneously, by precisely controlling distance f, the distance of the edge of the negative electrode tab 212 away from the positive electrode tab 211 along the second direction can be ensured to be moderate. Based on this, distance a is further optimized to ensure a reasonable relative position between the positive electrode tab 211 and the negative electrode tab 212, avoiding short-circuit risks and improving current transmission efficiency, thereby ensuring the overall performance and safety of the battery. Through the coordination of distances e, f, and a, a reasonable layout of the positive electrode tab 211 and the negative electrode tab 212 can be achieved. This ensures uniform current distribution within the battery, reduces internal resistance, improves overall performance, and effectively prevents localized overheating, ensuring safe use.

[0138] Similarly, by controlling distance g, the distance of the edge of the positive electrode tab 211 away from the negative electrode tab 212 along the second direction can be ensured to be moderate. Simultaneously, by precisely controlling distance h, the distance of the edge of the negative electrode tab 212 away from the positive electrode tab 211 along the second direction can be ensured to be moderate. Based on this, distance a is further optimized to ensure a reasonable relative position between the positive electrode tab 211 and the negative electrode tab 212, avoiding short-circuit risks and improving current transmission efficiency, thereby ensuring the overall performance and safety of the battery. Through the coordination of distances g, h, and a, a reasonable layout of the positive electrode tab 211 and the negative electrode tab 212 can be achieved. This ensures uniform current distribution within the battery, reduces internal resistance, improves overall performance, and effectively prevents localized overheating, ensuring safe use.

[0139] In some embodiments, combined with Figure 8 As shown, along the first direction, the lead-out length of the positive electrode tab 211 in the unfolded state is j, which satisfies: 15mm≤j≤45mm;

[0140] And / or, the lead-out length of the negative electrode tab 212 in the unfolded state is k, which satisfies: 15mm≤k≤45mm.

[0141] Since the tab 21 extends from the stacked cell 2, the tab 21 is in a free unfolded state before welding. After the tab 21 is welded and fixed, it is folded along a third direction toward the end face close to the stacked cell 2 in order to form a compact structure, reduce the space occupied, and ensure that the internal components of the battery are arranged in an orderly manner.

[0142] By limiting the lead-out length j of the positive electrode tab 211 in the unfolded state to within the range of 15mm≤j≤45mm, on the one hand, it avoids severe misalignment of the stacked cells 2, which would result in a small area for subsequent electrical connection of the positive electrode tab 211 and negative electrode tab 212, insufficient battery overcurrent capacity, and increased battery temperature rise; on the other hand, it also avoids an excessively long current path between the tab 21 and the cover plate 11, which would increase overcurrent resistance and result in insufficient battery overcurrent capacity.

[0143] For example, in this embodiment, the value of j can be 15mm or 18mm or 19mm or 21mm or 25mm or 32mm or 38mm or 42mm or 45mm, or it can be any range formed by any two of the above values.

[0144] Similarly, by limiting the lead-out length k of the negative electrode tab 212 in the unfolded state to within the range of 15mm≤k≤45mm, on the one hand, it avoids severe misalignment of the stacked cells 2, resulting in a small area for subsequent electrical connection of the positive electrode tab 211 and negative electrode tab 212, and insufficient battery overcurrent capacity; on the other hand, it also avoids an excessively long current path between the tab 21 and the cover plate 11, which would increase the overcurrent resistance and result in insufficient battery overcurrent capacity.

[0145] For example, in this embodiment, the value of k can be 15mm or 18mm or 19mm or 21mm or 25mm or 32mm or 38mm or 42mm or 45mm, or it can be any range formed by any two of the above values.

[0146] In some embodiments, the value range of a satisfies: 0.2≤a≤0.5.

[0147] By controlling the length j, the current-carrying capacity of the cell can be guaranteed while avoiding increased internal resistance and overheating caused by excessive lead length. Simultaneously, the stability of the welding area is ensured, improving current transmission efficiency. Based on this, the value of distance a can be further optimized to ensure a suitable spacing between the positive electrode tab 211 and the negative electrode tab 212, preventing short circuits while guaranteeing sufficient current-carrying capacity, thereby comprehensively improving battery performance and safety. Precisely adjusting the value of distance a not only optimizes the tab layout but also effectively balances current distribution, reduces energy consumption, and extends battery life.

[0148] Similarly, by controlling the length k, the current-carrying capacity of the cell can be guaranteed while avoiding increased internal resistance and overheating caused by excessive lead length, while ensuring the stability of the welding area and improving current transmission efficiency. Based on this, the value of distance a can be further optimized to ensure that the spacing between the positive electrode tab 211 and the negative electrode tab 212 is appropriate, preventing short circuits while ensuring sufficient current-carrying capacity, thereby comprehensively improving battery performance and safety. By precisely adjusting the value of distance a, not only can the tab layout be optimized, but the current distribution can also be effectively balanced, reducing energy consumption and extending battery life.

[0149] In some embodiments, combined with Figure 5 As shown, along the third direction, the positive electrode tab 211 is divided into at least two parts;

[0150] And / or, along a third direction, the negative electrode tab 212 is divided into at least two parts;

[0151] Among them, the third direction is perpendicular to both the first direction and the second direction.

[0152] Since the laminated cell 2 includes multiple stacked electrodes 20, each electrode 20 has a tab 21 leading out. The tabs 21 need to be folded together before welding. If all the tabs are folded together, the tabs will be thicker, occupying space in the casing and affecting the overall compactness of the cell structure. At the same time, if the tabs 21 are all folded to the same side, the misalignment width of the folded and stacked tabs 21 along a third direction will be larger, which will reduce the area of ​​the effective welding area, affect the welding quality, and reduce the current carrying capacity of the cell.

[0153] By dividing the positive electrode tab 211 into at least two parts along a third direction, the thickness of a single tab can be effectively reduced, the space occupied by the casing can be reduced, and the compactness of the cell structure can be improved. At the same time, the segmented design can reduce the misalignment width after the tab is folded, increase the effective welding area, improve the welding quality, further enhance the cell's overcurrent capacity, and ensure the stability and reliability of current transmission.

[0154] Similarly, by dividing the negative electrode tab 212 into at least two parts along a third direction, the thickness of a single tab can be effectively reduced, the space occupied by the casing can be reduced, and the compactness of the cell structure can be improved. At the same time, the segmented design can reduce the misalignment width after the tab is folded, increase the effective welding area, improve the welding quality, further enhance the cell's overcurrent capacity, and ensure the stability and reliability of current transmission.

[0155] In some embodiments, the length of the cell body 22 along the first direction is greater than the length of the cell body 22 along the second direction, and the tab 21 extends from one end of the cell body 22 along the first direction; satisfying: 0.15≤a≤0.45.

[0156] The length of the cell body 22 along the first direction is greater than the length of the cell body 22 along the second direction, wherein the long side of the cell body 22 is parallel to the first direction and the short side of the cell body 22 is parallel to the second direction.

[0157] The tab 21 extends from one end of the cell body 22 along the first direction, that is, the tab 21 is disposed on the short side of the cell body 22.

[0158] In some embodiments, the length of the cell body 22 along the second direction is greater than the length of the cell body 22 along the first direction, and the tab 21 extends from one end of the cell body 22 along the first direction; satisfying: 0.2≤a≤0.6.

[0159] The length of the cell body 22 along the second direction is greater than the length of the cell body 22 along the first direction. The long side of the cell body 22 is parallel to the second direction, and the short side of the cell body 22 is parallel to the first direction.

[0160] The tab 21 extends from one end of the cell body 22 along the first direction, that is, the tab 21 is disposed on the long side of the cell body 22.

[0161] When the tab 21 is located on the short side of the cell body 22, the area where a single tab 21 can be located 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 cell body 22 along the first direction can be guaranteed as much as possible, thereby ensuring the area of ​​the welding area and avoiding affecting the overcurrent.

[0162] When the tab 21 is located on the long side of the cell body 22, the area where a single tab 21 can be located is relatively large. 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 cell body 22 along the first direction are guaranteed, thereby ensuring the area of ​​the welding area and avoiding affecting the overcurrent.

[0163] In some embodiments, the laminated cell 2 includes a plurality of stacked electrodes 20, the number of layers of the electrodes 20 being greater than or equal to 80; and satisfying: 0.18≤a≤0.5.

[0164] The number of layers in electrode 20 refers to the sum of the number of layers in positive electrode 201 and negative electrode 202. The more layers in electrode 20, the greater the overall thickness of the laminated cell 2. Cell stacking leads to an increased risk of mis-layering. By reasonably controlling the range of b×a, the size of the tab 21 and the area of ​​the welding region are ensured, thereby maintaining the overall performance and overcurrent capacity of the laminated cell 2 and avoiding overcurrent problems caused by the increase in the number of layers.

[0165] In some embodiments, combined with Figure 9As shown, each electrode 20 extends along the first direction to form an electrode tab 21, and multiple electrode tabs 21 are folded along the third direction. The misalignment width of the electrode tab 21 on one side after folding and stacking along the third direction is m, which satisfies: 0.5mm≤m≤5mm.

[0166] Among them, the third direction is perpendicular to both the first direction and the second direction.

[0167] When the misalignment width m of the tab 21 after folding and stacking is too large along the third direction, the misalignment width is large, which leads to a reduction in the area of ​​the effective welding area, affecting the welding quality and reducing the current carrying capacity of the cell.

[0168] For example, in this embodiment, the value of m can be 0.5mm or 1mm or 1.2mm or 1.5mm or 1.8mm or 2mm or 2.2mm or 2.5mm or 3.5mm or 4mm or 5mm, or it can be any range formed by any two of the above values.

[0169] In some embodiments, combined with Figure 2 As shown, the shell body 12 has openings 121 at both ends along the first direction;

[0170] The positive electrode tab 211 and the negative electrode tab 212 are electrically connected to the electrode post 3 disposed on the cover plate 11, respectively.

[0171] According to an embodiment of the present invention, another aspect provides a battery pack including a plurality of batteries as described above, and a base plate on which the batteries are fixed.

[0172] The battery can be fixed to the base plate by adhesive bonding, riveting, screwing, or other methods.

[0173] In some embodiments, the end face of the lead tab 21 of the laminated cell 2 is arranged perpendicular to the surface of the base plate, satisfying: 14mm≤b×a≤350mm.

[0174] The end face of the lead tab 21 of the laminated cell 2 is set perpendicular to the surface of the base plate. When the battery pack vibrates as a whole, the tab 21 is subjected to greater force, which can easily lead to the positive and negative tabs overlapping. By controlling the formula range of b×a within 14mm≤b×a≤350mm, the risk of internal short circuit caused by the overlap of the positive and negative tabs is avoided. Increasing b is beneficial to increasing the contact area between the casing 1 and the base plate, improving the connection strength between the two. Increasing a makes the distance between the positive and negative tabs controllable.

[0175] In some embodiments, the end face of the lead tab 21 of the laminated cell 2 is arranged parallel to the surface of the base plate, satisfying: 10mm≤b×a≤300mm.

[0176] The end face of the lead tab 21 of the stacked cell 2 is parallel to the surface of the base plate, that is, the end face of the lead tab 21 of the stacked cell 2 is located on the bottom or top surface of the stacked cell 2. In this case, during battery pack vibration, the risk of tab overlap due to vibration of the positive and negative tabs is relatively small. Therefore, by controlling the formula range of b×a within 10mm≤b×a≤300mm, the overall overcurrent rate of the battery can be improved.

[0177] In some embodiments, the end face of the lead tab 21 of the laminated cell 2 is set away from the base plate, satisfying: 8mm≤b×a≤280mm.

[0178] The end face of the lead tab 21 of the stacked cell 2 is positioned away from the base plate, that is, the end face of the lead tab 21 of the stacked cell 2 is located on the bottom or top surface of the stacked cell 2. In this case, during battery pack vibration, the risk of tab overlap due to vibration of the positive and negative tabs is relatively small. Therefore, by controlling the formula range of b×a within 8mm≤b×a≤280mm, the overall overcurrent rate of the battery can be improved.

[0179] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Although 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 all such modifications and variations fall within the scope defined by the present invention.

Claims

1. A battery, characterized in that, include: Shell (1); The pole post (3) is disposed on the housing (1); A laminated battery cell (2) is disposed within the housing (1). The laminated battery cell (2) includes a battery cell body (22) and a tab (21) extending from one end of the battery cell body (22) along a first direction. The tab (21) is adapted to be electrically connected to the terminal post (3). The electrode tab (21) includes a positive electrode tab (211) and a negative electrode tab (212), both of which 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 spaced apart along a second direction, wherein the second direction is perpendicular to the first direction; The positive electrode tab (211) and the negative electrode tab (212) are spaced a1 apart along the second direction, and the width of the laminated cell (2) along the second direction is a2, satisfying a=a1 / a2; the length of the cell body (22) along the first direction is b, in mm; satisfying: 8mm≤b×a≤350mm; The value range of 'a' is: 0.08 ≤ a ≤ 0.6; The value range of b is: 80mm≤b≤780mm.

2. The battery according to claim 1, characterized in that, The shell (1) includes a shell body (12) and a cover plate (11). The shell body (12) has an opening (121) at at least one end along the first direction, and the cover plate (11) is provided to block the opening (121). The battery also includes a terminal assembly, which is disposed on the cover plate (11), and the tab (21) is led out toward the cover plate (11); satisfying: 8mm≤b×a≤300mm.

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

4. The battery according to claim 3, characterized in that, The negative electrode (202) extends beyond the positive electrode (201) by a dimension p along the first direction, satisfying 1mm≤p≤3mm.

5. The battery according to claim 1, characterized in that, The stacked cell (2) includes multiple stacked electrodes (20). Each electrode (20) includes an electrode body (23) and an electrode tab (21) extending from the electrode body (23). The electrode body (23) is provided with a protrusion (24) protruding in a direction perpendicular to the large surface of the electrode body (23), satisfying: 10mm≤b×a≤320mm.

6. The battery according to claim 5, characterized in that, The protrusions (24) include a plurality of protrusions (24) which are spaced apart along the second direction.

7. The battery according to claim 5, characterized in that, The height of the protrusion in the direction perpendicular to the large surface of the electrode body (23) is q, which satisfies 0.5mm≤q≤2mm.

8. The battery according to claim 1, characterized in that, The battery further includes: an adapter piece, which is electrically connected between the tab (21) and the post (3), and the tab (21) is partially disposed on the surface of the adapter piece away from the stacked cell (2); satisfying: 8mm≤b×a≤290mm.

9. The battery according to claim 1, characterized in that, The length b of the battery cell body (22) along the first direction is 300mm≤b≤780mm; at this time, the value of a is 0.2≤a≤0.

6.

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

11. The battery according to claim 10, characterized in that, The range of values ​​for 'a' is: 0.15 ≤ a ≤ 0.

45.

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

13. The battery according to claim 12, characterized in that, The range of values ​​for 'a' is: 0.2 ≤ a ≤ 0.

5.

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

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

45.

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

6.

17. The battery according to claim 1, characterized in that, The stacked cell (2) includes multiple stacked electrodes (20), the number of layers of the electrodes (20) is greater than or equal to 80; and satisfies: 0.18≤a≤0.

5.

18. The battery according to claim 17, characterized in that, Each of the electrode plates (20) extends along the first direction to form an electrode tab (21), and the multiple electrode tabs (21) are folded along the third direction. The misalignment width of the electrode tab (21) on one side after being folded and stacked along the third direction is m, which satisfies: 0.5mm≤m≤5mm; Wherein, the third direction is perpendicular to both the first direction and the second direction.

19. The battery according to claim 2, characterized in that, The shell body (12) has openings (121) at both ends along the first direction. The positive electrode tab (211) and the negative electrode tab (212) are electrically connected to the pole (3) disposed on the cover plate (11).

20. A battery pack, characterized in that, It includes a plurality of batteries as described in any one of claims 1 to 19 above, and also includes a base plate on which the batteries are fixed.

21. The battery pack according to claim 20, characterized in that, The end face of the stacked cell (2) leading out from the tab (21) is set perpendicular to the surface of the base plate, satisfying: 14mm≤b×a≤350mm.

22. The battery pack according to claim 20, characterized in that, The end face of the stacked cell (2) leading out from the tab (21) is set parallel to the surface of the base plate, satisfying: 10mm≤b×a≤300mm.

23. The battery pack according to claim 20, characterized in that, The end face of the stacked cell (2) leading out from the tab (21) is set away from the base plate, satisfying: 8mm≤b×a≤280mm.

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