Battery and electronic product

Abstract

The utility model relates to the field of batteries, and discloses a battery and an electronic product, the battery comprises a battery cell, a tab connected with the battery cell, and a membrane shell; the membrane shell is provided with a containing cavity, the battery cell is located in the containing cavity, and the tab part is exposed out of the containing cavity; the tabs extend along a first direction, the battery cell and the membrane shell are of arc-shaped structures bent along the first direction or a second direction, and the second direction is perpendicular to the first direction; the battery cell comprises first pole pieces, second pole pieces and diaphragms, the first pole pieces and the second pole pieces are alternately stacked, and the diaphragms are located between the first pole pieces and the second pole pieces; in the third direction, the length of the first pole piece closest to the central angle of the battery cell is smaller than that of the first pole piece farthest from the central angle, and / or the length of the second pole piece closest to the central angle is smaller than that of the second pole piece farthest from the central angle. The distance between the end part of the first pole piece and / or the second pole piece far away from one side of the central angle and the membrane shell is reduced, so that the space utilization rate of the membrane shell is improved, and the energy density of the battery is further improved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and particularly to a battery and an electronic product. Background Art

[0002] With the increasing popularity of wearable electronic devices (such as smart watches, smart clothes, etc.), in order to make the battery compartment of the wearable electronic device fit more closely with the contact part, the battery compartment is set to be curved. Correspondingly, the battery is also designed as a curved battery.

[0003] The battery cell includes a plurality of positive electrode sheets, negative electrode sheets and separators, and the outer layer of the battery cell is packaged by a film shell (such as an aluminum-plastic film). Among them, the lengths of the respective positive electrode sheets are equal, the lengths of the respective negative electrode sheets are equal, and the lengths of the respective separators are equal. After bending, the distance between the end of the electrode sheet farther from the central angle and the film shell is larger, resulting in a certain loss of space utilization rate in the film shell and a low energy density of the battery.

[0004] Therefore, how to solve the above technical problems should be the key concern of those skilled in the art. Summary of the Utility Model

[0005] The purpose of the present application is to provide a battery and its battery cell to improve the energy density of the battery.

[0006] To solve the above technical problems, the present application provides a battery including: a battery cell, a tab connected to the battery cell, and a film shell;

[0007] The film shell has a receiving cavity, the battery cell is located in the receiving cavity, and the tab is partially exposed outside the receiving cavity;

[0008] The tab extends along a first direction, and the battery cell and the film shell are arc-shaped structures bent along the first direction or a second direction, and the second direction is perpendicular to the first direction;

[0009] In a third direction, the battery cell has opposite first and second curved surfaces, and the film shell has opposite third and fourth curved surfaces; the third direction is perpendicular to the first direction and the second direction;

[0010] The battery cell includes a first electrode sheet, a second electrode sheet and a separator, the first electrode sheet and the second electrode sheet are alternately stacked, and the separator is located between the first electrode sheet and the second electrode sheet;

[0011] In the third direction, the length of the first electrode sheet closest to the central angle of the battery cell is less than the length of the first electrode sheet farthest from the central angle, and / or the length of the second electrode sheet closest to the central angle is less than the length of the second electrode sheet farthest from the central angle.

[0012] Optionally, the ratio range of the central angle to the target thickness is 0.5 to 3, and the target thickness is the thickness of the first pole piece or the thickness of the second pole piece.

[0013] Optionally, the angle range of the central angle is 10° to 150°, and / or the range of the target thickness is 50 μm to 150 μm.

[0014] Optionally, in the direction close to the central angle, the length of the first pole piece gradually decreases, and / or

[0015] in the direction close to the central angle, the length of the second pole piece gradually decreases.

[0016] Optionally, in the bending direction of the battery cell, the distance between the same ends of adjacent pole pieces with the same polarity is less than 5 mm.

[0017] Optionally, the difference range between the length of the first pole piece closest to the central angle and the length of the first pole piece farthest from the central angle is 0.2 mm to 1 mm; and / or the difference range between the length of the second pole piece closest to the central angle and the length of the second pole piece farthest from the central angle is 0.2 mm to 1 mm.

[0018] Optionally, the length of the separator closest to the central angle is less than the length of the separator farthest from the central angle.

[0019] Optionally, in the direction close to the central angle, the length of the separator gradually decreases.

[0020] This application also provides an electronic product, including the battery described in any one of the above.

[0021] A battery provided by the present application includes: an electrode core, a tab connected to the electrode core, and a film shell; the film shell has a receiving cavity, the electrode core is located in the receiving cavity, and the tab is partially exposed outside the receiving cavity; the tab extends along a first direction, and the electrode core and the film shell are arc-shaped structures bent along the first direction or a second direction, and the second direction is perpendicular to the first direction; in a third direction, the electrode core has opposite first and second curved surfaces, and the film shell has opposite third and fourth curved surfaces; the third direction is perpendicular to the first direction and the second direction; the electrode core includes a first electrode plate, a second electrode plate, and a separator, the first electrode plate and the second electrode plate are alternately stacked, and the separator is located between the first electrode plate and the second electrode plate; in the third direction, the length of the first electrode plate closest to the central angle of the electrode core is less than the length of the first electrode plate farthest from the central angle, and / or, the length of the second electrode plate closest to the central angle of the electrode core is less than the length of the second electrode plate farthest from the central angle.

[0022] It can be seen that the electrode core and the film shell in the battery of the present application are curved arc-shaped structures. The bending directions of the electrode core and the film shell include two types, one is the same as the extending direction of the tab, and the other is perpendicular to the extending direction of the tab. The electrode core includes alternately stacked first and second electrode plates, and a separator located between the first and second electrode plates. Since the length of the first electrode plate farthest from the central angle of the electrode core is greater than the length of the first electrode plate closest to the central angle of the electrode core, and the length of the second electrode plate farthest from the central angle of the electrode core is greater than the length of the second electrode plate closest to the central angle of the electrode core, the distance between the ends of the first and second electrode plates on the side of the electrode core away from the central angle and the film shell becomes smaller, which can improve the space utilization rate of the film shell, and further improve the energy density of the battery.

[0023] In addition, the present application also provides an electronic product having the above battery. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a schematic diagram of the distribution of the electrode core in the film shell in the related art;

[0026] Figure 2 It is a schematic structure of a battery provided by an embodiment of the present application Figure 1 ;

[0027] Figure 3 Schematic diagram of the structure of a battery provided by an embodiment of the present application Figure 2 ;

[0028] Figure 4 Schematic diagram of the distribution of a battery cell in a film shell provided by an embodiment of the present application;

[0029] Figure 5 Schematic diagram of the central angle formed by battery cells provided by an embodiment of the present application;

[0030] Figure 6 Schematic diagram of a battery cell before bending provided by an embodiment of the present application;

[0031] Figure 7 Schematic diagram of the distance between the ends of adjacent first pole pieces in a battery cell provided by an embodiment of the present application;

[0032] Figure 8 Schematic diagram of each positive electrode sheet after die-cutting provided by an embodiment of the present application;

[0033] Figure 9 Schematic diagram of each negative electrode sheet after die-cutting provided by an embodiment of the present application;

[0034] In the figure, 1 is the first pole piece, 2 is the second pole piece, 3 is the separator, 100 is the battery cell, 200 is the film shell, and 300 is the tab. Detailed implementation manners

[0035] In order to enable those skilled in the art to better understand the solution of the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific implementation manners. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0036] In the following description, many specific details are set forth in order to fully understand the present invention, but the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0037] As in the background art section, such as Figure 1As shown, the lengths of the first electrode tab, the second electrode tab, and the separator in the battery cell 100 are equal. After bending, the distance between the end of the electrode tab farther from the central angle and the film case 200 is larger, resulting in a certain loss of space utilization in the film case 200 and a low energy density of the battery. Moreover, the stress on the battery cell at the bending position is too large, and it is easy to occur that the electrode tab is broken or even the corresponding position of the film case is cracked, resulting in a low yield of the battery.

[0038] In view of this, the present application provides a battery, please refer to Figures 2 to 5 , including:

[0039] a battery cell 100, a tab 300 connected to the battery cell 100, and a film case 200;

[0040] The film case 200 has a receiving cavity, the battery cell 100 is located in the receiving cavity, and part of the tab 300 is exposed outside the receiving cavity;

[0041] The tab 300 extends in a first direction, and the battery cell 100 and the film case 200 are arc-shaped structures bent in the first direction or a second direction, and the second direction is perpendicular to the first direction;

[0042] In a third direction, the battery cell 100 has an opposite first bending surface and second bending surface, and the film case 200 has an opposite third bending surface and fourth bending surface; the third direction is perpendicular to the first direction and the second direction;

[0043] The battery cell 100 includes a first electrode tab 1, a second electrode tab 2, and a separator 3. The first electrode tab 1 and the second electrode tab 2 are alternately stacked, and the separator 3 is located between the first electrode tab 1 and the second electrode tab 2;

[0044] In the third direction, the length of the first electrode tab 1 closest to the central angle α of the battery cell 100 is less than the length of the first electrode tab 1 farthest from the central angle α, and / or the length of the second electrode tab 2 closest to the central angle α is less than the length of the second electrode tab 2 farthest from the central angle α.

[0045] The extending direction of the tab 300 is the first direction X, and the bending direction of the battery cell 100 and the film case 200 can be the first direction X, as Figure 2 shown, or the bending direction of the battery cell 100 and the film case 200 can be the second direction Y, as Figure 3 shown, and the third direction Z is perpendicular to the first direction X and the second direction Y respectively.

[0046] The film case 200 can be an aluminum-plastic film, and the inside of the film case 200 is filled with an electrolyte.

[0047] One of the first electrode sheet 1 and the second electrode sheet 2 is a positive electrode sheet, and the other is a negative electrode sheet. The structures of the positive electrode sheet 1 and the negative electrode sheet 2 can refer to the related art and will not be elaborated here in detail. The number of the positive electrode sheets 1 and the negative electrode sheets 2 is not limited in this embodiment and depends on the situation. The widths of the respective positive electrode sheets 1 can be equal, and the widths of the respective negative electrode sheets 2 can be equal.

[0048] The tab 300 includes a positive tab and a negative tab. The positive tab is connected to the positive electrode sheet, and the negative tab is connected to the negative electrode sheet.

[0049] The battery cell 100 is arc-shaped. The central angle α of the battery cell 100 is the included angle formed by the connecting lines between both ends of the battery cell 100 and the center of the circle, that is, the included angle formed by the normal lines perpendicular to the tangents at both ends of the arc respectively.

[0050] In the third direction, in this embodiment, there are three relationships for the length settings of the first electrode sheet 1 and the length settings of the second electrode sheet 2. First, the length of the first electrode sheet 1 closest to the central angle α of the battery cell 100 is less than the length of the first electrode sheet 1 farthest from the central angle α, and the length relationship between the second electrode sheets 2 is not limited; second, the length of the second electrode sheet 2 closest to the central angle α is less than the length of the second electrode sheet 2 farthest from the central angle α, and the length relationship between the first electrode sheets 1 is not limited; third, the length of the first electrode sheet 1 closest to the central angle α of the battery cell 100 is less than the length of the first electrode sheet 1 farthest from the central angle α, and the length of the second electrode sheet 2 closest to the central angle α is less than the length of the second electrode sheet 2 farthest from the central angle α.

[0051] Since the length of the first electrode sheet 1 farthest from the central angle α of the battery cell 100 is greater than the length of the first electrode sheet 1 closest to the central angle α of the battery cell 100, after the battery cell 100 is bent, the distance between the first electrode sheet 1 farthest from the central angle α of the battery cell 100 and the packaging shell film shell 200 decreases, reducing the blank area in the packaging shell film shell 200 and making more full use of the space of the packaging shell film shell 200; similarly, since the length of the negative electrode sheet farthest from the central angle α of the battery cell 100 is greater than the length of the negative electrode sheet closest to the central angle α of the battery cell 100, the distance between the negative electrode sheet farthest from the central angle α of the battery cell 100 and the packaging shell film shell 200 decreases, reducing the blank area in the packaging shell film shell 200 and making more full use of the space of the packaging shell film shell 200. Therefore, the space utilization rate of the packaging shell film shell 200 can be improved, thereby improving the energy density of the battery. Moreover, it helps to reduce the stress concentration inside the battery, reduces the risk of battery deformation or damage caused by stress concentration, improves the bending stress, and prevents the electrode sheet from breaking and piercing the separator 33.

[0052] It should be noted that in this embodiment, the difference between the length of the first pole piece 1 that is farthest from the central angle α of the battery cell 100 and the length of the first pole piece 1 that is closest to the central angle α of the battery cell 100 is not limited.

[0053] As an implementable manner, the difference range between the length of the first pole piece 1 that is closest to the central angle α of the battery cell 100 and the length of the first pole piece 1 that is farthest from the central angle α of the battery cell 100 is 0.2 mm to 1 mm. Among them, the specific length difference can be set by itself according to needs. For example, the difference can be 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, etc.

[0054] Each of the first pole pieces 1 is in a parallel relationship, and the current of each of the first pole pieces 1 is equal. The length of the first pole piece 1 that is farthest from the central angle α of the battery cell 100 is greater than the length of the first pole piece 1 that is closest to the central angle α of the battery cell 100. Therefore, the area of the first pole piece 1 that is farthest from the central angle α of the battery cell 100 is greater than the area of the first pole piece 1 that is closest to the central angle α of the battery cell 100. The current density of the first pole piece 1 that is closest to the central angle α of the battery cell 100 is high, and the current density of the first pole piece 1 that is farthest from the central angle α of the battery cell 100 is low, which helps to reduce the current concentration phenomenon inside the battery and reduce the influence of thermal effects on the battery performance. By distributing the current density more evenly, the local heat accumulation of the first pole piece 1 can be reduced, and the influence of thermal effects on the battery performance is reduced.

[0055] As an implementable manner, the difference range between the length of the second pole piece 2 that is closest to the central angle α of the battery cell 100 and the length of the second pole piece 2 that is farthest from the central angle α of the battery cell 100 is 0.2 mm to 1 mm. Among them, the specific length difference can be set by itself according to needs. For example, the difference can be 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, etc.

[0056] Each of the second pole pieces 2 is in a parallel relationship, and the current of each of the second pole pieces 2 is equal. The length of the second pole piece 2 that is farthest from the central angle α of the battery cell 100 is greater than the length of the second pole piece 2 that is closest to the central angle α of the battery cell 100. Therefore, the area of the second pole piece 2 that is farthest from the central angle α of the battery cell 100 is greater than the area of the second pole piece 2 that is closest to the central angle α of the battery cell 100. The current density of the second pole piece 2 that is closest to the central angle α of the battery cell 100 is high, and the current density of the second pole piece 2 that is farthest from the central angle α of the battery cell 100 is low, which helps to reduce the current concentration phenomenon inside the battery and reduce the influence of thermal effects on the battery performance. By distributing the current density more evenly, the local heat accumulation of the second pole piece 2 can be reduced, and the influence of thermal effects on the battery performance is reduced.

[0057] The function of the separator 3 is to isolate the first electrode sheet 1 and the second electrode sheet 2. In this embodiment, the length relationship of the separator 3 is not limited, as long as it can completely isolate the first electrode sheet 1 and the second electrode sheet 2.

[0058] As an implementable manner, the lengths of the separator layers 3 are equal. The separator 3 is relatively soft and prone to deformation. Setting the lengths of the separator layers 3 to be equal reduces the difficulty of setting the separator 3.

[0059] As another implementable manner, the length of the separator 3 closest to the central angle α of the battery cell 100 is less than the length of the separator 3 farthest from the central angle α of the battery cell 100, so that during the cyclic charge and discharge process of the battery, the current distribution is uniform, the heat concentration of the separator 3 is reduced, the thermal shrinkage of the separator 3 is prevented, and the cycle life of the battery is extended.

[0060] When the length of the separator 3 closest to the central angle α of the battery cell 100 is less than the length of the separator 3 farthest from the central angle α of the battery cell 100, the length relationship of the separator layers 3 is not limited in this embodiment. For example, in an embodiment of the present application, in the direction close to the central angle α of the battery cell 100, the length of the separator 3 can gradually decrease.

[0061] The separator 3 includes, but is not limited to, a polyethylene separator and a polypropylene separator.

[0062] In this embodiment, the battery cell 100 and the membrane case 200 in the battery are in a curved arc structure. There are two bending directions of the battery cell 100 and the membrane case, one is the same as the extending direction of the pole ear 300, and the other is perpendicular to the extending direction of the pole ear 300. The battery cell 100 includes the first electrode sheet 1 and the second electrode sheet 2 stacked alternately, and the separator 3 located between the first electrode sheet 1 and the second electrode sheet 2. Since the length of the first electrode sheet 1 farthest from the central angle α of the battery cell 100 is greater than the length of the first electrode sheet 1 closest to the central angle α of the battery cell 100, and the length of the second electrode sheet 2 farthest from the central angle α of the battery cell 100 is greater than the length of the second electrode sheet 2 closest to the central angle α of the battery cell 100, the distance between the ends of the first electrode sheet 1 and the second electrode sheet 2 on the side of the battery cell 100 away from the central angle α and the membrane case 200 becomes smaller, which can improve the space utilization rate of the membrane case 200, and further improve the energy density of the battery.

[0063] On the basis of the above embodiment, in an embodiment of the present application, the ratio range of the central angle α of the battery cell 100 to the target thickness can be 0.5 to 3, and the target thickness is the thickness of the first electrode sheet 1 or the second electrode sheet 2.

[0064] The specific ratio of the central angle α to the target thickness can be determined according to the situation. For example, the ratio of the central angle α to the target thickness can be 0.5, 1, 1.5, 2, 2.5, 3, etc.

[0065] It should be noted that in this embodiment, the target thickness and the central angle α are not specifically limited and can be set by oneself.

[0066] As an implementable manner, the angle range of the central angle α can be 10° to 150°, and / or the range of the target thickness can be 50 μm to 150 μm.

[0067] For example, the angle of the central angle α can be 10°, 30°, 50°, 80°, 100°, 120°, 150°, etc., and the specific angle can be determined according to the situation. The target thickness can be 50 μm, 70 μm, 90 μm, 110 μm, 130 μm, 150 μm, etc., and the specific thickness value can be determined according to the situation.

[0068] The ratio range of the central angle α to the target thickness is 0.5 to 3. When the length of the pole piece is fixed, it can prevent the central angle α from being too large and the stress in the first pole piece 1 and the second pole piece 2 from being too large, thereby reducing the probability of breakage of the first pole piece 1 and the second pole piece 2, improving the yield of the battery cell 100, and at the same time reducing the probability of membrane shell rupture and improving the yield of the battery.

[0069] Based on any of the above embodiments, in an embodiment of the present application, as Figure 6 shown, in the direction of the central angle α close to the battery cell 100, the length of the first pole piece 1 gradually decreases, and / or in the direction of the central angle α close to the battery cell 100, the length of the second pole piece 2 gradually decreases.

[0070] In the direction of the central angle α close to the battery cell 100, the length of the first pole piece 1 decreases layer by layer, that is, the area of the first pole piece 1 decreases layer by layer. When the current on each first pole piece 1 is the same, the current density of the first pole piece 1 increases layer by layer, making the current density more evenly distributed. The current density of the first pole piece 1 closest to the central angle α of the battery cell 100 is higher, and the current density of the first pole piece 1 farthest from the central angle α of the battery cell 100 is lower, which helps to reduce the current concentration phenomenon inside the battery and improve the stability and safety of the battery.

[0071] In the direction of the central angle α close to the battery cell 100, the length of the second pole piece 2 decreases layer by layer, that is, the area of the second pole piece 2 decreases layer by layer. When the current on each second pole piece 2 is the same, the current density of the second pole piece 2 increases layer by layer, making the current density more evenly distributed. The current density of the second pole piece 2 closest to the central angle α of the battery cell 100 is higher, and the current density of the second pole piece 2 farthest from the central angle α of the battery cell 100 is lower, which helps to reduce the current concentration phenomenon inside the battery and improve the stability and safety of the battery.

[0072] It should be noted that in this embodiment, the distance between the ends of adjacent pole pieces with the same polarity is not limited.

[0073] As an implementable manner, in the bending direction of the battery cell 100, the distance between the same ends of adjacent and identically polarized electrode plates is less than 5 mm. Among them, the electrode plates are the first electrode plates or the second electrode plates. For a battery as shown in Figure 2 , the bending direction of the battery cell 100 is the first direction X; for a battery as shown in Figure 3 , the bending direction of the battery cell 100 is the second direction Y.

[0074] The distance L between the same ends of adjacent and identically polarized electrode plates refers to the distance between the same ends of adjacent and identically polarized electrode plates in the bending direction of the battery cell 100, as shown in Figure 7 .

[0075] The distance between the ends of adjacent and identically polarized electrode plates is less than 5 mm. On the one hand, it can ensure the full utilization of the film shell space, improve the space utilization rate, and enhance the energy density of the battery; on the other hand, it can also ensure the normal charging and discharging of the first electrode plate 1 and the second electrode plate 2, and avoid the phenomenon of lithium plating.

[0076] The distance between the ends of adjacent and identically polarized electrode plates can be 4.5 mm, 3.5 mm, 2.5 mm, 1.5 mm, 0.5 mm, etc., depending on the specific situation.

[0077] As an implementable manner, at both ends of the battery cell 100, the ends of all the first electrode plates 1 are flush, and the ends of all the second electrode plates 2 are flush. That is, the distance between the ends of adjacent and identically polarized electrode plates is zero.

[0078] On the basis of any of the above embodiments, in an embodiment of the present application, in order to prevent the risk of lithium plating, the width of the second electrode plate 2 is greater than the width of the adjacent first electrode plate 1, and the length of the second electrode plate 2 is greater than the length of the adjacent first electrode plate 1.

[0079] The differences in length and width between the second electrode plate 2 and the adjacent first electrode plate 1 depend on the specific situation and are not specifically limited in this embodiment. For example, the difference in width between the second electrode plate 2 and the adjacent first electrode plate 1 can be greater than 0.2 mm, and the difference in length between the second electrode plate 2 and the adjacent first electrode plate 1 can be greater than 0.2 mm to better prevent lithium plating.

[0080] The present application also provides an electronic product, including the battery according to any of the above embodiments.

[0081] The following introduces the battery manufacturing method in the present application with a specific situation.

[0082] Step 1, Electrode plate incoming material: The normal positive electrode plate incoming material is a roll material.

[0083] Step 2. Die-cutting of the positive electrode sheet: When die-cutting the positive electrode sheet, the widths of the n positive electrode sheets are equal (in the non-arc direction), and the lengths of the n positive electrode sheets are C 1 、C 2 、…、C n-1 、C n are die-cut incrementally. As shown in Figure 8 , where the length of the positive electrode sheet: 0 < C i-1 / C i < 1, i = 2, 3, …, n; When die-cutting, it is preferably to use laser to die-cut the positive electrode sheet, with good flexibility.

[0084] Step 3. Die-cutting of the negative electrode sheet: When die-cutting the negative electrode sheet, the widths of the n negative electrode sheets are equal (in the non-arc direction), and the lengths of the n negative electrode sheets are A 1 、A 2 、…、A n-1 、A n are die-cut incrementally. As shown in Figure 9 , where the length of the negative electrode sheet: 0 < A i-1 / A i < 1, i = 2, 3, …, n. The width and length of the negative electrode sheet are larger than those of the adjacent positive electrode sheet, the width difference is greater than 0.2 mm, and the length difference is greater than 0.2 mm; When die-cutting, it is preferably to use laser to die-cut the electrode sheet, with good flexibility.

[0085] Step 4. Stacking: Stack the positive electrode sheet, separator, and negative electrode sheet in sequence to prepare a stacked core.

[0086] Step 5. Bending of the stacked core: Use an arc-shaped hot pressing fixture to heat, press, and shape the stacked core according to the set radian to form a bent battery cell.

[0087] Step 6. Encapsulation and liquid injection: Place the battery cell into the prepared film shell, inject electrolyte and perform encapsulation to form a battery.

[0088] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other.

[0089] The above has introduced the battery and its battery cell provided by this application in detail. Specific examples are used in this article to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the solution and core idea of this application. It should be noted that for those of ordinary skill in the art, without departing from the principle of this application, several improvements and modifications can be made to this application, and these improvements and modifications also fall within the protection scope of this application.

Claims

1. A battery, characterized in that: include: A battery cell, and a tab and a membrane shell connected to the battery cell; The membrane shell has a containing cavity, the battery cell is located in the containing cavity, and the pole ear portion is exposed outside the containing cavity; The pole ear extends along a first direction, the battery cell and the membrane shell are arc-shaped structures bent along the first direction or the second direction, and the second direction is perpendicular to the first direction; In a third direction, the battery cell has a first curved surface and a second curved surface opposite to each other, and the membrane shell has a third curved surface and a fourth curved surface opposite to each other; the third direction is perpendicular to the first direction and the second direction; The battery cell comprises a first pole piece, a second pole piece and a diaphragm, the first pole piece and the second pole piece are alternately stacked, and the diaphragm is located between the first pole piece and the second pole piece; In the third direction, the length of the first pole piece closest to the central angle of the battery cell is smaller than the length of the first pole piece farthest from the central angle, and / or the length of the second pole piece closest to the central angle is smaller than the length of the second pole piece farthest from the central angle.

2. The battery according to claim 1, characterized in that The ratio of the central angle to the target thickness ranges from 0.5 to 3, and the target thickness is the thickness of the first pole piece or the thickness of the second pole piece.

3. The battery according to claim 2, characterized in that The central angle ranges from 10° to 150°, and / or the target thickness ranges from 50 μm to 150 μm.

4. The battery according to claim 1, characterized in that In the direction close to the central angle, the length of the first pole piece gradually decreases, and / or, In a direction approaching the central angle, the length of the second pole piece gradually decreases.

5. The battery according to claim 4, characterized in that In the bending direction of the battery core, the distance between the same ends of adjacent pole pieces with the same polarity is less than 5 mm.

6. The battery according to claim 1, characterized in that The difference between the length of the first pole piece closest to the central angle and the length of the first pole piece farthest from the central angle ranges from 0.2mm to 1mm; and / or the difference between the length of the second pole piece closest to the central angle and the length of the second pole piece farthest from the central angle ranges from 0.2mm to 1mm.

7. The battery according to any one of claims 1 to 6, characterized in that: The length of the diaphragm closest to the central angle is smaller than the length of the diaphragm farthest from the central angle.

8. The battery according to claim 7, characterized in that In a direction approaching the central angle, the length of the diaphragm gradually decreases.

9. An electronic product, characterized in that: Comprising the battery according to any one of claims 1 to 8.

Images