Battery monomer, battery device and electric equipment

Abstract

The utility model relates to the technical field of batteries, and discloses a battery monomer, a battery device and electric equipment, the battery monomer comprises a shell, an electrode assembly, a first tab and a first adhesive tape, the electrode assembly is constructed as a laminated battery cell, and the laminated battery cell comprises a positive plate, a negative plate and a diaphragm; the multiple positive plates and the multiple negative plates are sequentially stacked in the thickness direction of the electrode assembly, and diaphragms are arranged between the adjacent positive plates and the adjacent negative plates and on the outer side of the positive plate and / or the negative plate on the outermost side in the thickness direction of the electrode assembly; the electrode assembly is provided with a first side face and a second side face which are opposite to each other in the width direction, the first adhesive tape is adhered to the first side face, the total length of the first adhesive tape is D1, the size of one end of the diaphragm exceeding one end of the same side of the negative plate in the width direction of the electrode assembly is h, and h * D1 is larger than or equal to 15mm < 2 > and smaller than or equal to 1800mm < 2 >. According to the battery monomer, the reliability of the battery is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a battery monomer, a battery device and an electric equipment. BACKGROUND

[0002] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy saving and environmental protection advantages. For electric vehicles, battery technology is an important factor for their development.

[0003] During the use of the battery, the reliability of the battery is a problem that cannot be ignored. Therefore, how to improve the reliability of the battery is a technical problem that needs to be solved today. CONTENT OF THE INVENTION

[0004] The present application provides a battery monomer, a battery device and an electric equipment, the reliability of the battery monomer is improved.

[0005] In order to achieve the above purpose, the main technical scheme adopted by the present application includes:

[0006] In a first aspect, the present application provides a battery monomer, comprising a shell, an electrode assembly, a first tab and a first adhesive tape: the shell has a receiving cavity; the electrode assembly is arranged in the receiving cavity, and the electrode assembly is configured as a laminated cell, the laminated cell comprising a positive electrode sheet, a negative electrode sheet and a separator, the positive electrode sheet and the negative electrode sheet are both multiple and are stacked in turn along the thickness direction of the electrode assembly, and the separator is arranged between adjacent positive electrode sheets and negative electrode sheets and on the outer side of the outermost positive electrode sheet and / or negative electrode sheet along the thickness direction of the electrode assembly; the thickness direction is parallel to the stacking direction of the positive electrode sheet and the negative electrode sheet; the first tab is arranged at one end of the electrode assembly in the length direction; wherein the electrode assembly has a first side and a second side opposite in the width direction, the length direction, the thickness direction and the width direction of the electrode assembly are perpendicular to each other, the first adhesive tape is at least one, and the first adhesive tape is bonded to the first side, along the length direction of the electrode assembly, the total length of the first adhesive tape is D1, along the width direction of the electrode assembly, the size of one end of the separator beyond the same end of the negative electrode sheet is h, and the following conditions are met: 15mm 2 ≤h*D1≤1800mm 2 .

[0007] The battery monomer provided by the embodiments of the present application is provided with a diaphragm between adjacent positive electrode sheets and negative electrode sheets and outside the outermost positive electrode sheet and / or negative electrode sheet along the thickness direction of the electrode assembly, which can effectively isolate the positive electrode and the negative electrode and reduce the probability of short circuit in the battery. After the battery cell is stacked, the plurality of electrode sheets and diaphragms are in a loose state, and the first adhesive tape arranged on the side can bind the layered positive electrode sheet, negative electrode sheet and diaphragm together, thereby reducing the looseness of the electrode assembly, reducing the local lithium ion transmission impedance, and facilitating lithium ion transmission. By controlling the sum of the size of the first adhesive tape and the size of one end of the diaphragm beyond the same end of the negative electrode sheet to meet the above range, the first adhesive tape is used to bind the electrode assembly, which is conducive to lithium ion transmission in the subsequent charging and discharging process. On the one hand, the adhesive tape is prevented from being too narrow, and at the same time, the diaphragm is prevented from being too small towards the negative electrode, thereby reducing the probability of diaphragm folding when the adhesive tape is fixed, thereby reducing the probability of short circuit after the diaphragm is folded, and at the same time ensuring that the adhesive tape has sufficient binding force on the electrode assembly. On the other hand, the adhesive tape is prevented from being too wide, and the diaphragm is prevented from being too large towards the negative electrode, thereby reducing the probability of position deviation when the adhesive tape is bonded, reducing the pulling force of the adhesive tape on the diaphragm, and at the same time reducing the risk of diaphragm folding caused by the adhesive tape being too narrow, thereby improving the reliability of the battery.

[0008] In a second aspect, the embodiments of the present application provide a battery device comprising the battery monomer as described in the above embodiments.

[0009] In a third aspect, the embodiments of the present application provide a power consumption device comprising the battery device as described in the above embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0011] Figure 1 It is the overall structure schematic diagram in the embodiments of the present application;

[0012] Figure 2 It is the overall structure schematic diagram of the electrode assembly in the embodiments of the present application;

[0013] Figure 3 It is the enlarged structure schematic diagram of one end of the electrode assembly in the embodiments of the present application;

[0014] Figure 4 It is the front view of one end of the electrode assembly in the embodiments of the present application;

[0015] Figure 5 It is Figure 4a partial enlarged structural schematic view of the electrode assembly;

[0016] Figure 6 is Figure 4 another partial enlarged structural schematic view of the electrode assembly;

[0017] Figure 7 is a top structural schematic view of the electrode assembly in the embodiment of the present application;

[0018] Figure 8 is a front view of one end of the electrode assembly in the embodiment of the present application;

[0019] Figure 9 is a front sectional view of the electrode assembly in the embodiment of the present application.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 100: housing; 101: accommodating cavity; 110: end cover; 111: first end cover; 111a: first pole post assembly; 112: second end cover; 112a: second pole post assembly; 120: shell;

[0022] 200: electrode assembly; 201: stacked sheet cell; 210: positive electrode sheet; 220: negative electrode sheet; 230: separator;

[0023] 201: first side face; 202: second side face; 203: third side face; 204: fourth side face;

[0024] 300: first adhesive tape; 301: first part; 302: second part; 303: third part; 304: fourth part;

[0025] 400: second adhesive tape;

[0026] 500: first pole lug; 600: second pole lug;

[0027] 700: negative electrode unit; 720: first separator; 730: second separator;

[0028] X: length direction; Y: width direction; Z: thickness direction. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the specification herein is for describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, all terms used in disclosing the application, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms used in the description of the present application and its objects specifically discussed herein are intended to be read in the broadest possible manner consistent with the principles of the applications. Termini "comprising", "having", "including", and "containing" are to be construed open- ended, i.e., to mean "including, but not limited to", unless otherwise noted.

[0031] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily all directed to the same embodiments.

[0032] In the description of the application, it is necessary to explain that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "attachment" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0033] The term "and / or" in the application is only a description of the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can mean that there are three cases of A alone, A and B together, and B alone. In addition, the character " / " in the application generally represents that the front and rear associated objects have an "or" relationship.

[0034] "Multiple" appearing in the application means more than two (including two), and similarly, "multiple groups" means more than two groups (including two groups), and "multiple pieces" means more than two pieces (including two pieces).

[0035] As an example, the battery monomer includes a battery cell formed by taking the positive and negative electrode sheets as the carrier of electrochemical material, preventing short circuit by separating the positive and negative electrode sheets by the diaphragm, taking the electrolyte as the carrier of ion transmission, realizing structural protection by the shell, and realizing connection with the external circuit by the terminal.

[0036] In some embodiments, the positive electrode sheet includes a positive electrode current collector, and the positive electrode current collector has a plurality of surfaces, at least one surface of which is provided with a positive electrode active material.

[0037] As an example, the positive electrode active material is located on the surface of the positive electrode current collector along its own thickness direction.

[0038] As an example, the positive electrode current collector can be a metal foil or a composite current collector. When the positive electrode current collector includes a metal foil, it can be at least one of the following: silver-plated aluminum, silver-plated stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium. When the positive electrode current collector includes a composite current collector, the composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0039] As an example, positive electrode active materials include, but are not limited to, the following materials: lithium phosphates, lithium transition metal oxides and their respective modified compounds, and other conventional materials that can be used as positive electrode active materials for batteries may also be used.

[0040] In some embodiments, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material. The negative electrode current collector may be a metal foil or a composite current collector. When the negative electrode current collector includes a metal foil, it may be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, or at least one of carbon, nickel, or titanium.

[0041] As an example, the negative electrode active material is disposed on the surface of the negative electrode current collector along its thickness direction.

[0042] As examples, negative electrode active materials include, but are not limited to, the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, and may also employ other conventional materials known in the art that can be used as battery negative electrode active materials. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys, but this application is not limited to these materials. These negative electrode active materials may be used alone or in combination of two or more.

[0043] In some embodiments, the diaphragm can be any known porous diaphragm with good chemical and mechanical stability.

[0044] As an example, the main material of the separator includes at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film, and is not particularly limited. When the separator is a multi-layer composite film, the materials of the layers can be the same or different, and are not particularly limited. The isolation component can be a separate component located between the positive and negative electrodes, or can be attached to the surface of the positive and negative electrodes.

[0045] In some embodiments, the positive electrode sheet, the negative electrode sheet, and the separator form a stack structure. The stack structure refers to the stacking of separate sheet-like structures of the positive electrode sheet, the negative electrode sheet, and the separator. Both the positive electrode sheet and the negative electrode sheet are discontinuous, and are discontinuous between adjacent layers. In addition, the separator in this application can also be a separate sheet, which is discontinuous. In another embodiment, the separator can be continuous, and the positive electrode sheet and the negative electrode sheet are discontinuous, thereby forming a Z-shaped stack structure.

[0046] In some embodiments, the housing includes at least one of a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film. The housing can encapsulate components such as the positive electrode sheet, the negative electrode sheet, and the separator.

[0047] In some embodiments, the housing includes an end cap and a shell, the shell is provided with an opening, and the end cap closes the opening to form a sealed space for containing the electrode assembly and electrolyte and the like. The shell can be provided with one or more openings. The end cap can also be provided with one or more, and the end cap can also be used to set other structural parts of the battery, such as electrode terminals, pressure relief mechanisms, liquid injection holes, etc., which are not limited in this application.

[0048] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab of the electrode assembly. The electrode terminal can function as a circuit transmission, and the electrode terminal can be subsequently connected to a bus bar or the like to achieve electrical connection between multiple battery monomers. The electrode terminal can be provided on the end cap or on the shell.

[0049] The battery still faces some challenges in actual application, among which the wrinkling of the separator is a common problem. The wrinkling of the separator not only affects the performance and safety of the battery, but also can cause short circuit, thermal runaway, and other serious consequences.

[0050] In the laminated electrode cell, a plurality of electrode plates are arranged in a laminated manner. Compared with the case where the conventional cell is wrapped by the separator, the cell is less constrained, and the side of the cell needs to be fixed by using the adhesive tape. When the adhesive tape is fixed, because the separator is in a multi-layer dispersed state, the separator is prone to wrinkling. After the separator is wrinkled and folded, the electrode plate may be dropped, thereby causing uneven distribution of the internal resistance of the battery. In the low internal resistance area, the battery may be partially overcharged or overdischarged during the cycle process, thereby affecting the consistency and cycle performance of the battery. In severe cases, it may cause short circuit, thermal runaway and other serious consequences. Meanwhile, after the separator is wrinkled and folded, the positive and negative electrodes may directly contact and cause short circuit.

[0051] In view of this, in order to improve the reliability of the battery, the embodiments of the present application provide a battery monomer, please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 9 , the battery monomer comprises a shell 100, an electrode assembly 200, a first tab 500 and a first adhesive tape 300.

[0052] The shell 100 has a receiving cavity 101, and the electrode assembly 200 is arranged in the receiving cavity 101. It can be understood that the shell 100 can provide structural protection for the electrode assembly 200 in the receiving cavity 101, which helps to improve the reliability of the battery.

[0053] The electrode assembly 200 is configured as a laminated electrode cell 201, which comprises a positive electrode plate 210, a negative electrode plate 220 and a separator 230. The positive electrode plate 210 and the negative electrode plate 220 are both multiple and are stacked in sequence along the thickness direction Z of the electrode assembly 200. It can be understood that the sequence of stacking refers to the alternative arrangement of one positive electrode plate, one negative electrode plate, another positive electrode plate and another negative electrode plate arranged in sequence along the thickness direction of the electrode assembly 200, and the number of stacked positive electrode plates and negative electrode plates is not limited. By stacking a plurality of positive electrode plates 210 and negative electrode plates 220, the power density of the battery can be improved.

[0054] As an example, the laminated electrode cell 201 refers to a plurality of independent sheet-shaped positive electrode plates 210 and negative electrode plates 220 stacked, and each positive electrode plate 210 and negative electrode plate 220 is independent of each other.

[0055] The separator 230 is arranged between the adjacent positive electrode plate 210 and negative electrode plate 220, and the outer side of the outermost positive electrode plate 210 and / or negative electrode plate 220 along the thickness direction Z of the electrode assembly 200. It can be understood that the separator 230 as an electronic insulator effectively prevents the risk of internal short circuit of the battery during normal operation of the battery.

[0056] The first tab 500 is arranged at one end of the electrode assembly 200 in the length direction X, and can function to transmit the current inside the battery cell and electrically connect with the corresponding electrode terminal. The material of the first tab 500 can be the same as that of the current collector, and can specifically be at least one of aluminum, stainless steel, copper, aluminum, nickel, carbon, silver, nickel, or titanium, which can be surface-plated with silver.

[0057] As an example, the material of the first adhesive tape 300 can be a polyimide film (PI film), an acrylic imide film (PPA film), or a polyethylene film.

[0058] The electrode assembly 200 has a first side surface 201 and a second side surface 202 opposite to each other in the width direction Y, and the first adhesive tape 300 is at least one and is attached to the first side surface 201. It can be understood that a plurality of first adhesive tapes 300 can collectively fix the electrode assembly 200, thereby ensuring the binding effect of the electrode assembly 200 and reducing the probability of the battery cell loosening.

[0059] Please refer to Figure 7 , the total length of the first adhesive tape 300 is D1 along the length direction X of the electrode assembly 200, and the dimension of one end of the separator 230 beyond the same end of the negative electrode sheet 220 along the width direction Y of the electrode assembly 200 is h, which satisfies: 15mm 2 ≤h*D1≤1800mm 2 . Thus, the electrode assembly 200 can be bound, the probability of the positive electrode sheet 210, the negative electrode sheet 220, and the separator 230 loosening can be reduced, the lithium ion transmission effect between the positive electrode sheet 210, the negative electrode sheet 220, and the separator 230 can be ensured, and the separator 230 can be prevented from being wrinkled and folded, thereby reducing the risk of electrode sheet dropping and positive and negative electrode short circuit.

[0060] It should be noted that when the number of the first adhesive tape 300 is one, the total length of the first adhesive tape 300 refers to the dimension of the single first adhesive tape 300 along the length direction X of the electrode assembly 200, and when the number of the first adhesive tape 300 is multiple, the total length of the first adhesive tape 300 refers to the sum of the dimensions of the multiple first adhesive tapes 300 along the length direction X of the electrode assembly 200.

[0061] In the above scheme, by controlling the sum of the dimensions of the multiple first adhesive tapes 300 and the dimension of one end of the separator 230 extending beyond the same side of the negative electrode 220 to meet the above range, on the one hand, the pressure-bearing area of ​​the separator 230 can be increased and the pressure on the separator 230 can be reduced when the tapes are fixed, thus reducing the probability of wrinkles and folds at the edge of the separator 230, thereby reducing the risk of short circuit between the positive and negative electrodes and ensuring insulation between the positive electrode 210 and the negative electrode 220; on the other hand, it can ensure that the dimension of the same side of the separator 230 and the negative electrode 220 is not too large, and the dimension of the first adhesive tapes 300 is not too large, thereby reducing the probability of positional displacement when the tapes are fixed, reducing the risk of the first adhesive tapes 300 pulling the separator 230, and reducing the impact on heat dissipation of the electrode assembly 200, thereby improving the reliability of the battery.

[0062] Optionally, h*D1 can be 15mm. 2 150mm 2 300mm 2 450mm 2 600mm 2 750mm 2 900mm 2 1050mm 2 1200mm 2 1350mm 2 1500mm 2 1650mm 2 1800mm 2 .

[0063] As an example, h*D1 is preferably 100mm. 2 ≤h*D1≤600mm 2 At this time, h*D1 can be 100mm 2 120mm 2 150mm 2 200mm 2 250mm 2 300mm 2 350mm 2 400mm 2 450mm 2 500mm 2 560mm 2 570mm 2 580mm 2 590mm 2 600mm 2, by further controlling h * D1 to meet the above preferred range, thereby further reducing the risk of diaphragm folding, positive and negative short circuit; At the same time, further reduce the probability of position deviation when the adhesive tape is fixed, reduce the risk of adhesive tape pulling the diaphragm.

[0064] In some embodiments, h meets: 0.5mm≤h≤3mm.

[0065] In the above scheme, by further controlling the size of one end of the diaphragm 230 beyond the same end of the negative electrode sheet 220 to meet the above range, on the one hand, it can reduce the probability of diaphragm 230 folding caused by pulling diaphragm 230 when the adhesive tape is fixed, thereby reducing the risk of positive and negative contact short circuit; On the other hand, it can avoid the diaphragm 230 being too large in size beyond the negative electrode sheet 220, reducing the influence on the heat dissipation of the battery cell.

[0066] Optionally, h can be 0.5mm, 0.7mm, 0.9mm, 1.1mm, 1.3mm, 1.5mm, 1.7mm, 1.9mm, 2.1mm, 2.3mm, 2.5mm, 2.7mm, 3mm.

[0067] D1 meets: 20mm≤D1≤650mm.

[0068] In the above scheme, by controlling the sum of the sizes of the plurality of first adhesive tapes 300 to meet the above range, on the one hand, it can improve the binding force of the plurality of first adhesive tapes 300 on the battery cell, reducing the probability of battery cell bulging; On the other hand, it can reduce the influence of the first adhesive tape 300 on the heat dissipation of the electrode assembly 200, reduce the probability of poor heat dissipation of the electrode assembly 200, and also reduce the manufacturing cost of the battery cell.

[0069] Optionally, D1 can be 20mm, 30mm, 40mm, 60mm, 90mm, 150mm, 200mm, 250mm, 300mm, 350mm, 400mm, 450mm, 500mm, 530mm, 580mm, 610mm, 630mm, 650mm.

[0070] As an example, D1 is preferably 60mm≤D1≤300mm, at this time, D1 can be 60mm, 70mm, 80mm, 90mm, 100mm, 150mm, 200mm, 250mm, 260mm, 270mm, 280mm, 290mm, 300mm.

[0071] h is preferably 1mm≤h≤2.5mm, at this time, h can be 1mm, 1.1mm, 1.3mm, 1.5mm, 1.7mm, 1.9mm, 2.1mm, 2.3mm, 2.5mm.

[0072] As an example, the following Table 1 test result table is the battery short circuit rate and cell temperature test results of a plurality of specific examples and comparative examples.

[0073] Table 1. Test result table

[0074]

[0075] The meaning of the battery short circuit rate is the ratio of the number of batteries that have short-circuited to the total number of batteries 100, and the formula is (number of batteries that have short-circuited / 100)*100%. The short-circuit test method of the battery short circuit rate includes using a pulse short-circuit tester, connecting the positive and negative tabs of the bare cell, and testing the voltage between the positive and negative tabs. If the pulse voltage rise Vp is less than 200V, it is determined that the battery has short-circuited. If the pulse voltage rise Vp reaches 200V or above, it is determined that the battery has not short-circuited.

[0076] The cell temperature test method includes loading the cell into a shell, sealing the shell and the cover plate by welding, and setting a pole on the cover plate. The specific test steps are as follows, wherein,

[0077] 1) For lithium iron phosphate batteries: charge at 4C rate constant current to 3.65V, and charge at constant voltage until the current drops to 0.05C; for ternary batteries: charge at 4C rate constant current to 4.25V, and charge at constant voltage until the current drops to 0.05C; connect a temperature sensor to the pole, sample the temperature of the pole during charging, and obtain the maximum temperature T of the pole area. When the maximum temperature T of the pole area is ≤45℃, it is good, when 45℃

[0078] From the above test results, it can be seen that the parameters of Example 1, Example 2, Example 3, Example 4, Example 5, Example 6, Example 7, Example 8, Example 9, and Example 10 are all within the protection range of h, D1, and h*D1 of the present application, the temperature test results are all good, and the short circuit rate is less than 20%.

[0079] Among them, the parameter h in Example 1-Example 5 is within the preferred protection range of h of the present application, the parameter D1 in Example 1-Example 5 is within the preferred protection range of D1 of the present application, the parameter h*D1 in Example 1-Example 5 is within the preferred protection range of h*D1 of the present application, and the temperature test results of Example 1-Example 5 are all good and no short-circuit occurs.

[0080] The parameters h and D1 in Example 6 and Example 7 are not in the preferred protection range of the corresponding parameters, the parameter h*D1 is in the corresponding range of the preferred embodiment described above, the temperature test results of Example 6 are all good and no short circuit occurs, and the temperature test results of Example 7 are good but the battery short circuit rate is 2%.

[0081] The parameters h and D1 in Example 8 are in the preferred protection range of the corresponding parameters, the parameter h*D1 is not in the preferred protection range of the corresponding parameters, and Example 8 has no short circuit and the temperature test result is only qualified.

[0082] Each parameter in Example 9 and Example 10 is not in the preferred range of the corresponding parameter, the temperature test result of Example 9 is good but the battery short circuit rate is 5%, and Example 10 has no short circuit but the temperature test result is only qualified.

[0083] The parameter h*D1 in Comparative Example 1 is not in the preferred range of the corresponding parameter, which is lower than the lower limit of the protection range of the corresponding parameter, at this time, the probability of the diaphragm 230 being wrinkled and folded due to the pulling of the diaphragm 230 during the fixing of the adhesive tape is increased, thereby increasing the risk of positive and negative electrode contact short circuit, so that the battery short circuit rate is as high as 75%, and the battery temperature rise is large, and the temperature test result is unqualified.

[0084] The parameter h*D1 in Comparative Example 2 is not in the preferred range of the corresponding parameter, which is higher than the upper limit of the protection range of the corresponding parameter, at this time, the diaphragm 230 is easily torn during the fixing of the adhesive tape, thereby increasing the risk of positive and negative electrode contact short circuit, so that the battery short circuit rate reaches 20%, and at the same time, due to the diaphragm 230 being too large in size than the positive plate 220, the heat dissipation of the battery cell is affected, the battery heat dissipation rate is reduced, the battery temperature rise is large, and the temperature test result is unqualified.

[0085] It can be seen that the parameter range of the present application reduces the battery short circuit rate and reduces the maximum temperature of the battery pole area, thereby improving the reliability of the battery.

[0086] In other embodiments, please refer to Figure 4 , Figure 5 and Figure 6 , the electrode assembly 200 has a third side surface 203 and a fourth side surface 204, the third side surface 203 and the fourth side surface 204 are oppositely arranged along the thickness direction Z of the electrode assembly 200;

[0087] The first adhesive tape 300 includes a first portion 301, a second portion 302 and a third portion 303 connected in sequence, the first portion 301 is bonded to the third side surface 203, the second portion 302 is bonded to the first side surface 201, and the third portion 303 is bonded to the fourth side surface 204, h satisfies: 0.5mm≤h≤2.5mm, and D1 satisfies: 30mm≤D1≤600mm.

[0088] In the above scheme, the first portion 301, the second portion 302 and the third portion 303 of the first adhesive tape 300 can be integrally formed as a whole or sequentially fixed to form a whole, which is not limited in the present application.

[0089] The first portion 301 of the first adhesive tape 300 is bonded to the third side surface 203, the third portion 303 is bonded to the fourth side surface 204, and the second portion 302 is bonded to the first side surface 201. It can be understood that the first adhesive tape 300 forms a U-shaped structure bound to the side surface of the electrode assembly 200. It can be understood that when the adhesive tape is fixed, the diaphragm 230 is relatively soft in texture, and the diaphragm 230 is easily affected by the force during the bonding of the adhesive tape to generate wrinkles and folds. Therefore, by controlling h and D1 to meet the above range, on the one hand, the probability of the diaphragm 230 being wrinkled and folded when the adhesive tape is fixed is further reduced, and on the other hand, the sum of the sizes of the plurality of first adhesive tapes 300 can be appropriately reduced according to the needs, thereby further reducing the influence on the heat dissipation of the electrode assembly 200 and further reducing the probability of poor heat dissipation of the battery cell.

[0090] Alternatively, h can be 0.5mm, 0.7mm, 0.9mm, 1.1mm, 1.3mm, 1.5mm, 1.7mm, 1.9mm, 2.1mm, 2.3mm, 2.5mm.

[0091] Alternatively, D1 can be 30mm, 40mm, 60mm, 90mm, 150mm, 200mm, 250mm, 300mm, 350mm, 400mm, 450mm, 500mm, 530mm, 580mm, 600mm.

[0092] In other embodiments, please refer to Figure 4 , along the width direction Y of the electrode assembly 200, the size of the first portion 301 is L1, and the size of the third portion 303 is L2, which satisfies: 5mm≤L1≤40mm, 5mm≤L2≤40mm.

[0093] In the above scheme, by controlling L1 and L2 in the above range, on the one hand, the connection strength between the first adhesive tape 300 and the electrode assembly 200 can be improved, thereby enhancing the binding effect of the first adhesive tape 300 on the diaphragm 230, reducing the probability of the battery cell being loose, reducing the local lithium ion transmission impedance, and being beneficial to improve the overall performance of the battery; on the other hand, it is beneficial to reduce the probability of the adhesive tape fixing position deviating during bonding and fixing, thereby reducing the risk of the first adhesive tape 300 tearing the diaphragm 230, and at the same time, the influence on the heat dissipation of the electrode assembly 200 can be reduced, and the probability of poor heat dissipation of the battery cell is further reduced.

[0094] Optionally, L1 can be 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, or 40 mm.

[0095] Optionally, L2 can be 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, or 40 mm.

[0096] In some embodiments, referring to Figure 7 , the plurality of first adhesive tapes 300 are arranged along the length direction X of the electrode assembly 200.

[0097] In the above scheme, since the plurality of first adhesive tapes 300 are arranged along the length direction X of the electrode assembly 200, the first adhesive tapes 300 can be firmly attached to the surface of the electrode assembly 200, playing a role in fixing the electrode assembly 200. On the one hand, this reduces the difficulty of bonding and reduces the probability that the first adhesive tapes 300 will be displaced and tear the separator 230. On the other hand, this reduces the probability of local loosening of the battery cell and reduces the lithium ion transmission impedance between the positive and negative electrodes, thereby facilitating improvement of the overall performance of the battery.

[0098] In some embodiments, referring to Figure 7 , the distance between the two adjacent first adhesive tapes 300 along the length direction X of the electrode assembly 200 is L3, which satisfies: 20 mm≤L3≤70 mm.

[0099] In the above scheme, since the distance between the two adjacent first adhesive tapes 300 satisfies the above range, on the one hand, this avoids too large a distance between the adjacent first adhesive tapes 300, improves the binding effect on the battery cell, and reduces the probability of excessive loosening of the electrode assembly 200 between the adjacent first adhesive tapes 300, thereby reducing the lithium ion transmission impedance between the positive and negative electrodes. On the other hand, this avoids too small a distance between the adjacent first adhesive tapes 300, reduces the probability of the separator 230 between the adjacent first adhesive tapes 300 being pulled when fixed by the two adhesive tapes, and thereby reduces the probability of the separator 230 between the adjacent first adhesive tapes 300 being folded.

[0100] Optionally, L3 can be 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, or 70 mm.

[0101] As an example, when the two adjacent first adhesive tapes 300 are not arranged in parallel or have different sizes along the length direction X of the electrode assembly 200, the minimum distance between the two along the length direction X of the electrode assembly 200 satisfies the above range, which can avoid too small a distance between the adjacent first adhesive tapes 300, reduce the probability of the separator 230 between the adjacent first adhesive tapes 300 being pulled when fixed by the two adhesive tapes, and thereby reduce the probability of the separator 230 between the adjacent first adhesive tapes 300 being folded.

[0102] In some embodiments, referring to Figure 7 The size of the first adhesive tape 300 along the length direction X of the electrode assembly 200 satisfies 8mm≤d≤100mm.

[0103] In the above scheme, since the size of the first adhesive tape 300 along the length direction X of the electrode assembly 200 satisfies the above range, on the one hand, the size of the first adhesive tape 300 is prevented from being too small, the stress area of the separator 230 is increased, the pressure on the separator 230 is reduced, the risk of the separator 230 being wrinkled and folded is reduced, and the risk of the exposed positive and negative poles being short-circuited is reduced. On the other hand, the size of the first adhesive tape 300 is prevented from being too large, the probability of the adhesive tape being fixed at an offset position during bonding is reduced, the risk of the first adhesive tape 300 tearing the separator 230 is reduced, and the influence of the first adhesive tape 300 on the heat dissipation of the electrode assembly 200 is reduced, and the probability of the electrode assembly 200 being poorly heat-dissipated is reduced.

[0104] Optionally, d can be 8mm, 18mm, 28mm, 38mm, 48mm, 58mm, 68mm, 78mm, 88mm, 98mm, or 100mm.

[0105] As an example, the sizes of the at least two first adhesive tapes 300 along the length direction X of the electrode assembly 200 are different.

[0106] It can be understood that the sizes of the plurality of first adhesive tapes 300 along the length direction X of the electrode assembly 200 can be the same or different, so as to facilitate improving the fixing effect at different positions as needed. For example, the widths of the first adhesive tapes 300 at both ends along the length direction X of the electrode assembly 200 can be the same and different from the widths of the first adhesive tapes 300 in other regions, so as to further reduce the probability of the separator 230 being wrinkled and ensure the heat dissipation effect of the electrode assembly 200.

[0107] In some embodiments, referring to Figure 7 The size of the negative pole piece 220 along the width direction Y of the electrode assembly 200 exceeds the size of the positive pole piece 210 by a value less than or equal to 2mm.

[0108] The d satisfies 10mm≤d≤100mm.

[0109] In the above scheme, by controlling the size of the negative pole piece 220 along the width direction Y of the electrode assembly 200 to exceed the size of the positive pole piece 210 by a value less than or equal to 2mm, it is ensured that the edge of the separator 230 has sufficient pressure from the positive pole piece 210, so as to further reduce the probability of the separator 230 being folded and reduce the risk of the positive pole piece 210 and the negative pole piece 220 being short-circuited after the separator 230 is folded.

[0110] In addition, the risk of short circuit between the negative electrode sheet and the positive electrode sheet caused by the folding of the diaphragm can be reduced, and the probability of lithium precipitation on the surface of the negative electrode sheet caused by the excessively small size of the negative electrode sheet can be avoided. On the other hand, the probability of the reduction of the energy density of the battery caused by the excessive size of the negative electrode sheet can be reduced, thereby improving the safety and stability of the battery.

[0111] The size of the negative electrode sheet 220 exceeds the size of the positive electrode sheet 210 by a value greater than or equal to 0.5 mm.

[0112] By controlling d to satisfy the above range, the stress area of the diaphragm 230 is further increased, the pressure on the diaphragm 230 is reduced, thereby reducing the risk of folding of the diaphragm 230 and the risk of short circuit between the electrode sheets. On the other hand, the size of the first adhesive tape 300 is avoided to be too large, thereby reducing the probability of displacement of the adhesive tape during fixing, thereby reducing the risk of tearing of the diaphragm 230 by the first adhesive tape 300.

[0113] Optionally, d can be 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, or 100 mm.

[0114] In other embodiments, please refer to Figure 6 and Figure 7 The battery cell further comprises a plurality of second adhesive tapes 400, and the second adhesive tapes 400 are attached to the second side surface 202.

[0115] It can be understood that the second adhesive tape 400 can be firmly attached to the side surface of the electrode assembly 200, thereby fixing the electrode assembly 200 and reducing the probability of direct contact between the positive electrode sheet 210 and the negative electrode sheet 220.

[0116] Along the length direction X of the electrode assembly 200, the sum of the sizes of the plurality of second adhesive tapes 400 is D2, and satisfies: 15 mm 2 ≤ h * D2 ≤ 1800 mm 2 .

[0117] In the above scheme, since the ratio of the sum of the sizes of the plurality of second adhesive tapes 400 to the size of the one end of the separator 230 beyond the one end of the negative plate 220 on the same side satisfies the above range, on the one hand, the pressing area of the separator 230 can be increased when the adhesive tape is fixed, and the pressure received by the separator 230 can be reduced, thereby reducing the probability of wrinkles and folds occurring at the edge of the separator 230, and reducing the risk of positive and negative short circuits. On the other hand, it can be ensured that the size of the separator 230 beyond the one end of the negative plate 220 on the same side is not too large, and the size of the second adhesive tape 400 is not too large, thereby reducing the probability of positional deviation when the adhesive tape is fixed, reducing the risk of the second adhesive tape 400 pulling the separator 230, and reducing the impact on the heat dissipation of the electrode assembly 200, thereby reducing the probability of poor heat dissipation of the electrode assembly 200.

[0118] Optionally, h*D2 can be 15mm 2 , 150mm 2 , 300mm 2 , 450mm 2 , 600mm 2 , 750mm 2 , 900mm 2 , 1050mm 2 , 1200mm 2 , 1350mm 2 , 1500mm 2 , 1650mm 2 , 1800mm 2 .

[0119] In some embodiments, the length of the electrode assembly 200 is greater than or equal to 300mm, and D1 satisfies 35mm≤D1≤600mm.

[0120] In the above scheme, by controlling the length of the electrode assembly 200 to be greater than or equal to 300mm, the length of the electrode assembly 200 is increased, which helps to improve the energy density of the battery. At the same time, the electrode assembly is more likely to be loose, therefore, D1 is further controlled to satisfy the above range, and the size of the adhesive tape in the length direction X of the electrode assembly 200 is increased, thereby improving the binding effect of the adhesive tape on the plurality of plates. Specifically, the length of the electrode assembly 200 can be greater than or equal to 300mm and less than or equal to 1000mm; specifically, it can be 300mm, 400mm, 500mm, 600mm, 700mm, 800mm, 900mm, or 1000mm.

[0121] By controlling D1 to meet the above range, the binding force of the electrode assembly 200 is further improved, which is beneficial to lithium ion transmission in the subsequent charging and discharging process. On the other hand, the size of the first adhesive tape 300 is ensured not to be too large, thereby reducing the probability of position deviation of the adhesive tape during fixing, reducing the risk of the first adhesive tape 300 pulling the separator 230, and reducing the risk of electrode sheet material falling or positive and negative electrode short circuit.

[0122] Optionally, D1 can be 35 mm, 45 mm, 65 mm, 95 mm, 155 mm, 205 mm, 255 mm, 305 mm, 355 mm, 405 mm, 455 mm, 505 mm, 535 mm, 585 mm, 605 mm.

[0123] In some other embodiments, the thickness of the separator 230 is greater than or equal to 8 μm and less than or equal to 40 μm.

[0124] In the above scheme, by controlling the thickness of the separator 230 to meet the above range, on the one hand, it prevents the thickness from being too thin, which makes it difficult to fix and easy to fold, thereby reducing the probability of folding of the separator 230. On the other hand, it prevents the thickness from being too thick, which brings about excessive internal resistance, is beneficial to reduce the energy loss of the battery during charging and discharging, improves the charging and discharging efficiency of the battery, enables the battery to complete the charging process faster, and enables the battery to output greater current during discharging, thereby improving the overall performance of the battery.

[0125] In some other embodiments, please refer to Figure 8 The plurality of separators 230 includes a first separator 720 and a second separator 730, and the first separator 720 and the second separator 730 are arranged on both sides of the negative electrode sheet 220 along the thickness direction of the electrode assembly to form a negative electrode unit 700, and the first separator 720 and the second separator 730 are both bonded and sealed to at least part of the negative electrode sheet 220.

[0126] The plurality of negative electrode units 700 and the plurality of positive electrode sheets 210 are sequentially stacked.

[0127] In the above scheme, the negative electrode sheet 220, the first separator 720 and the second separator 730 are configured as the negative electrode unit 700, which realizes modular design. At this time, the first separator 720 and the second separator 730 are bonded and sealed to at least part of the negative electrode sheet 220 to form a sealed structure and increase the hardness of the separator 230 at the edge sealing position, thereby reducing the risk of folding of the separator 230. It is beneficial to set the size of the first adhesive tape 300 along the length direction X of the electrode assembly 200 to be smaller, thereby reducing the probability of the adhesive tape pulling the separator 230, and further reducing the risk of folding of the separator 230.

[0128] In some other embodiments, please refer to Figure 2 and Figure 9The battery monomer further comprises a second tab 600, the first tab 500 and the second tab 600 are opposite in polarity, and the first tab 500 and the second tab 600 are respectively arranged at two ends of the electrode assembly 200 in the length direction X.

[0129] It can be understood that when a plurality of battery monomers need to be connected in series or parallel, the layout of the tabs at both ends makes the connection of the busbar simpler and more convenient, and the positive and negative tabs at both ends of the electrode assembly 200 in the length direction X can also avoid heat being concentrated on one side of the electrode assembly 200, thereby ensuring the heat dissipation effect of the electrode assembly 200 and reducing the probability of heat concentration.

[0130] In other embodiments, referring to Figure 9 The shell 100 comprises a shell 120 and end covers 110, the shell 120 and the end covers 110 surround a containing cavity 101, the end covers 110 are a plurality of, the plurality of end covers 110 comprise a first end cover 111 and a second end cover 112, the first end cover 111 and the second end cover 112 are respectively located at two ends of the shell 120 in the length direction X, the first end cover 111 and the second end cover 112 are respectively provided with a first pole assembly 111a and a second pole assembly 112a, and the first pole assembly 111a and the second pole assembly 112a are respectively electrically connected with the first tab 500 and the second tab 600.

[0131] It can be understood that the pole assembly is used for electrical connection between the battery and an external circuit, for example, the pole assembly can be connected with a busbar, etc., to realize series and parallel connection between a plurality of battery monomers, which is not limited in the present application.

[0132] In the above scheme, the pole assembly is electrically connected with the tab, which can provide a stable conduction path for the current inside the battery. The first pole assembly 111a is connected with the first tab 500, and the second pole assembly 112a is connected with the second tab 600, so that the current can be orderly transmitted from the electrode to the pole through the tab during the charging and discharging process of the battery, and then to the external circuit, thereby ensuring that the battery can stably output or input current and ensuring normal work of the battery.

[0133] It can be understood that the tab can be directly connected with the pole assembly; or the tab can be connected through an intermediate piece such as a conversion piece, specifically, the tab can be connected with the conversion piece first, and the conversion piece is electrically connected with the pole assembly, which is not limited in the present application.

[0134] In addition, the first pole post assembly 111a and the second pole post assembly 112a are connected with the corresponding tabs respectively, which can fix and support the tabs to some extent, so that the position of the tabs in the battery is more stable. At the same time, the end cover 110 and the shell 120 surround the accommodating cavity 101, and the connection of the pole post assembly and the tab also helps to enhance the stability of the structure of the entire shell 100, so that the internal structure of the battery is not easy to be displaced or damaged when the battery is subjected to external force impact or vibration.

[0135] In some other embodiments, the embodiments of the present application provide a battery device comprising the battery cell according to any one of the above embodiments.

[0136] Since the battery device according to the embodiments of the present application has the battery cell according to any one of the above embodiments, the performance and safety of the battery device are improved, and the reliability is better.

[0137] In some other embodiments, the embodiments of the present application provide a power consuming device comprising the battery device according to the above embodiments.

[0138] Since the power consuming device according to the embodiments of the present application has the battery device according to the above embodiments, the reliability of the power consuming device is improved.

[0139] The battery device disclosed by the embodiments of the present application can be used in, but is not limited to, a power consuming device such as a vehicle, a ship or an aircraft. A power supply system of the power consuming device can be composed of the battery cell, the battery device and the like disclosed by the present application.

[0140] The embodiments of the present application provide a power consuming device using a battery cell as a power supply. The power consuming device can be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, an electric toy, an electric tool, an electric bicycle, an electric motorcycle, an electric vehicle, a ship, a spacecraft and the like. The electric toy can include a fixed or mobile electric toy, such as a game console, an electric vehicle toy, an electric ship toy and an electric aircraft toy and the like. The spacecraft can include an airplane, a rocket, a space shuttle and a spacecraft and the like.

[0141] The following embodiments are described by taking a vehicle as an example for convenience of description.

[0142] The vehicle includes one of a fuel automobile, a gas automobile or a new energy automobile. The new energy automobile includes, but is not limited to, a pure electric vehicle, a hybrid electric vehicle or a range extended electric vehicle. The vehicle is provided with a battery at the bottom, the head or the tail. The battery supplies power to the vehicle. The battery serves as an operating power supply of the vehicle 1000, and supplies power to the circuit system of the vehicle, including meeting the working power demand of the vehicle during starting, navigation and running.

[0143] The vehicle further comprises a controller and a motor, the controller being configured to control the battery to supply power to the motor to meet the power demand of the vehicle during starting, navigation and driving.

[0144] In some embodiments of the present application, the battery can not only serve as the operating power source of the vehicle, but also serve as the driving power source of the vehicle, replacing or partially replacing the fuel or natural gas to provide driving power for the vehicle.

[0145] The battery comprises a box body and battery cells accommodated in the box body. The box body can adopt various structures. In some embodiments, the box body comprises a first sub-box body and a second sub-box body, the first sub-box body and the second sub-box body are combined to form the box body, and the first sub-box body and the second sub-box body jointly define an accommodation space for accommodating the battery cells. The second sub-box body comprises a square structure with one side open, the first sub-box body comprises a square structure with one side open, and the openings of the first sub-box body and the second sub-box body are correspondingly combined to jointly define the accommodation space with the first sub-box body and the second sub-box body. The first sub-box body comprises a plate structure, and the opening side of the first sub-box body and the second sub-box body is covered.

[0146] In the battery, the battery cells comprise a plurality of battery cells, which can be connected in series, in parallel or in a mixed manner. The mixed connection means that some of the plurality of battery cells are connected in series and some are connected in parallel. The plurality of battery cells can be directly connected in series, in parallel or in a mixed manner, and the whole of the plurality of battery cells is accommodated in the box body. Of course, the battery can also be in the form of a plurality of battery modules connected in series, in parallel or in a mixed manner, and a plurality of battery modules are connected in series, in parallel or in a mixed manner to form a whole, which is accommodated in the box body. The battery can also comprise other structures, for example, the battery can also comprise a busbar component for realizing the electrical connection between the plurality of battery cells.

[0147] The battery cells comprise at least one of a secondary battery or a primary battery; the battery cells include but are not limited to lithium-sulfur batteries, sodium-ion batteries or magnesium-ion batteries.

[0148] It should be further noted that the terms "comprising", "containing" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a list of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent in such a process, method, article or apparatus. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or apparatus that includes the element.

[0149] The various embodiments in the specification are described in progressive manner, and the same or similar parts among the embodiments can be referred to each other. The embodiments mainly explain the differences from other embodiments. Especially, the system embodiments are described simply because they are basically similar to the method embodiments, and the relevant parts can be referred to the description of the method embodiments.

[0150] The above only describes the embodiments of the present application and is not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the scope of claims of the present application.

[0151] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that, include: The outer shell has a receiving cavity; An electrode assembly is disposed within the receiving cavity. The electrode assembly is configured as a stacked cell. The stacked cell includes a positive electrode, a negative electrode, and a separator. There are multiple positive and negative electrodes, which are stacked sequentially along the thickness direction of the electrode assembly. The separator is disposed between adjacent positive and negative electrodes, and on the outermost positive and / or negative electrode along the thickness direction of the electrode assembly. The thickness direction is parallel to the stacking direction of the positive and negative electrodes. A first electrode tab is disposed at one end of the electrode assembly in the length direction; The electrode assembly has a first side and a second side opposite each other in the width direction. The length, thickness, and width directions of the electrode assembly are perpendicular to each other. The battery cell includes a first adhesive tape, at least one of which is adhered to the first side. The total length of the first adhesive tape along the length direction of the electrode assembly is D1. Along the width direction of the electrode assembly, one end of the separator extends beyond the same side end of the negative electrode sheet by a dimension h, satisfying: 15mm. 2 ≤h*D1≤1800mm 2 .

2. The battery cell according to claim 1, characterized in that, The h satisfies: 0.5mm≤h≤3mm, and the D1 satisfies: 20mm≤D1≤650mm.

3. The battery cell according to claim 1, characterized in that, The h*D1 satisfies 100mm 2 ≤h*D1≤600mm 2 .

4. The battery cell according to claim 1, characterized in that, The electrode assembly has a third side and a fourth side, and the third side and the fourth side are disposed opposite to each other along the thickness direction of the electrode assembly. The first tape includes a first part, a second part, and a third part connected in sequence. The first part is adhered to the third side, the second part is adhered to the first side, and the third part is adhered to the fourth side. The h satisfies: 0.5mm≤h≤2.5mm, and the D1 satisfies: 30mm≤D1≤600mm.

5. The battery cell according to claim 4, characterized in that, Along the width direction of the electrode assembly, the first part has a dimension of L1, and the third part has a dimension of L2, satisfying: 5mm≤L1≤40mm, 5mm≤L2≤40mm.

6. The battery cell according to claim 1, characterized in that, Multiple first tapes are spaced apart along the length of the electrode assembly.

7. The battery cell according to claim 6, characterized in that, Along the length of the electrode assembly, the distance between two adjacent first tapes among the plurality of first tapes is L3, which satisfies: 20mm≤L3≤70mm.

8. The battery cell according to claim 1, characterized in that, The first tape has a size d, which satisfies 8mm≤d≤100mm.

9. The battery cell according to claim 8, characterized in that, Along the width direction of the electrode assembly, the size of the negative electrode exceeds the size of the positive electrode by less than or equal to 2 mm; the value of d satisfies 10 mm ≤ d ≤ 100 mm.

10. The battery cell according to claim 1, characterized in that, The battery cell also includes a plurality of second adhesive tapes, which are adhered to the second side. Along the length of the electrode assembly, the sum of the dimensions of the plurality of second tapes is D2, satisfying: 15mm 2 ≤h*D2≤1800mm 2 .

11. The battery cell according to claim 1, characterized in that, The length of the electrode assembly is greater than or equal to 300 mm, and D1 satisfies 35 mm ≤ D1 ≤ 600 mm.

12. The battery cell according to claim 1, characterized in that, The thickness of the diaphragm is greater than or equal to 8 μm and less than or equal to 40 μm.

13. The battery cell according to claim 1, characterized in that, The plurality of diaphragms include a first diaphragm and a second diaphragm. Along the thickness direction of the electrode assembly, the first diaphragm and the second diaphragm are disposed on both sides of the negative electrode sheet to form a negative electrode unit. The first diaphragm and the second diaphragm are both bonded to and seal at least a portion of the negative electrode sheet. Multiple negative electrode units and multiple positive electrode plates are stacked sequentially.

14. The battery cell according to claim 1, characterized in that, The battery cell also includes a second tab, and the first tab and the second tab have opposite polarities. The first tab and the second tab are respectively disposed at both ends of the electrode assembly in the length direction.

15. The battery cell according to claim 14, characterized in that, The outer casing includes a housing and end caps, which enclose the receiving cavity. There are multiple end caps, including a first end cap and a second end cap. The first end cap and the second end cap are respectively located at both ends of the housing along its length. The first end cap and the second end cap are respectively provided with a first pole post assembly and a second pole post assembly, which are electrically connected to the first electrode tab and the second electrode tab, respectively.

16. A battery device, characterized in that, Includes the battery cell according to any one of claims 1-15.

17. An electrical appliance, characterized in that, Includes the battery cell according to any one of claims 1-15 or the battery device according to claim 16.

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