Pole piece, battery cell, battery and electric equipment

Abstract

The utility model discloses a pole piece, a battery cell, a battery and electric equipment. The pole piece comprises a current collector, an active substance layer and an expansive filling piece, the current collector has a bearing surface; the active material layer is arranged on one side where the bearing surface of the current collector is located, and a to-be-filled part is arranged on one side, deviating from the bearing surface, of the active material layer; the expansive filling piece is arranged on the to-be-filled part. The expansive filling piece in the design is configured to expand by being heated to extrude the current collector so as to enable the current collector to generate displacement and / or deformation, so that a gap is generated between the pole piece and the diaphragm of the battery cell, and the possibility of short circuit caused by contact of the positive pole piece and the negative pole piece is reduced; the occurrence of battery explosion caused by thermal runaway of the battery is reduced, so that the safety performance of the battery is effectively improved.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and in particular, to an electrode sheet, an electric core, a battery, and an electrical device using the same. Background Art

[0002] Lithium-ion batteries have advantages such as high energy density, long cycle life, no memory effect, and low self-discharge rate, and are widely used in fields such as mobile communication devices, portable electronic devices, and energy storage systems.

[0003] Currently, the safety issue of batteries has become an important concern in various fields. With the rapid development of various fields, higher requirements have been put forward for the safety issue of batteries. Therefore, how to improve the safety performance of batteries has become an urgent problem to be solved. Summary of the Utility Model

[0004] Embodiments of this application provide an electrode sheet, an electric core, a battery, and an electrical device using the same, which can solve the problem of poor safety performance of batteries in related technologies.

[0005] In a first aspect, an embodiment of this application provides an electrode sheet; the electrode sheet includes a current collector, an active material layer, and an expandable filler. The current collector has a bearing surface, the active material layer is disposed on one side where the bearing surface of the current collector is located, a portion to be filled is provided on the side of the active material layer facing away from the bearing surface, and the expandable filler is disposed in the portion to be filled.

[0006] In a second aspect, an embodiment of this application provides an electric core; the electric core includes the above-mentioned electrode sheet, and the electrode sheet is at least one of a positive electrode sheet and a negative electrode sheet.

[0007] In a third aspect, an embodiment of this application provides a battery; the battery includes a housing, an electrolyte, and the above-mentioned electric core. The housing has a receiving cavity, the electrolyte is poured into the receiving cavity of the housing, and the above-mentioned electric core is disposed in the receiving cavity of the housing.

[0008] In a fourth aspect, an embodiment of this application provides an electrical device; the electrical device includes a housing and the above-mentioned battery. The housing has a battery mounting groove, and the above-mentioned battery is mounted in the housing corresponding to the battery mounting groove.

[0009] Based on the electrode sheet, the electric core, the battery, and the electrical device according to the embodiments of this application, by disposing the expandable filler in the portion to be filled on the side of the active material layer facing away from the bearing surface of the current collector, a force is generated between the expandable filler and the active material layer during the expansion process of the expandable filler when heated, and the current collector is extruded, so that the current collector moves and / or bends in a direction away from the separator of the electric core under the action of the extrusion force, so as to generate a gap between the electrode sheet and the separator of the electric core, reducing the possibility of short circuit caused by the contact between the positive electrode sheet and the negative electrode sheet, thereby reducing the occurrence of thermal runaway of the battery resulting in battery explosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in 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 skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0011] Figure 1 It is a schematic partial cross-sectional structure diagram of a battery cell in the related art;

[0012] Figure 2 It is a schematic partial cross-sectional structure diagram of an external spike piercing the separator of a battery cell in the related art;

[0013] Figure 3 It is a schematic partial cross-sectional structure diagram of a current collector and an active material layer in an embodiment of the present application;

[0014] Figure 4 It is a schematic partial cross-sectional structure diagram of a pole piece in an embodiment of the present application;

[0015] Figure 5 It is a schematic partial cross-sectional structure diagram of a battery cell in an embodiment of the present application;

[0016] Figure 6 It is a schematic partial cross-sectional structure diagram of an external spike piercing the separator of a battery cell in an embodiment of the present application;

[0017] Figure 7 It is a schematic partial cross-sectional structure diagram of a pole piece in another embodiment of the present application;

[0018] Figure 8 It is a schematic partial cross-sectional structure diagram of a battery cell in another embodiment of the present application;

[0019] Figure 9 It is a schematic partial cross-sectional diagram of an external spike piercing the separator of a battery cell in another embodiment of the present application;

[0020] Figure 10 It is a schematic partial cross-sectional structure diagram of an external spike piercing the separator of a battery cell in yet another embodiment of the present application;

[0021] Figure 11 It is a schematic partial cross-sectional structure diagram of an external spike piercing the separator of a battery cell in still another embodiment of the present application;

[0022] Figure 12 It is a schematic partial cross-sectional structure diagram of an external spike piercing the separator of a battery cell in yet another embodiment of the present application.

[0023] Reference numerals: 10a', positive electrode tab; 10b', negative electrode tab; 21', separator; 30', external spike body;

[0024] 10, electrode tab; 10a, positive electrode tab; 10b, negative electrode tab; 11, current collector; 11a, bearing surface; 12, active material layer; 13, area to be filled; 13a, groove; 14, swellable filling member; 15, flame-retardant filling member; 21, separator; 30, external spike body. Detailed implementation manners

[0025] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0026] Lithium-ion batteries have advantages such as high energy density, long cycle life, no memory effect, and low self-discharge rate, and are widely used in fields such as mobile communication devices, portable electronic devices, and energy storage systems.

[0027] At present, the safety issue of batteries has become an important concern in various fields. With the rapid development of various fields, higher requirements have also been put forward for the safety issue of batteries. Regarding the safety issue of batteries, before leaving the factory, batteries usually undergo a nail penetration test to simulate the safety issues that may occur in the usage scenarios after leaving the factory.

[0028] As Figure 1 shown, in the related art, a battery includes a battery cell, and the battery cell includes a positive electrode tab 10a', a negative electrode tab 10b', and a separator 21'. The separator 21' is disposed between the positive electrode tab 10a' and the negative electrode tab 10b'. The nail penetration test is usually used to simulate the usage scenario in which the separator 21' of the battery is pierced by an external spike body 30' (such as an iron nail) after leaving the factory. For Figure 2 the battery structure shown in the related art, after the separator 21' is pierced by the external spike body 30', the internal temperature of the battery rises, causing the separator 21' to contract (the heat causes the thermal motion of the separator material to increase, and the intermolecular interaction force weakens, so it contracts when heated). The positive electrode tab 10a' and the negative electrode tab 10b' will come into contact to form a short circuit, generating a large current and causing the battery to experience thermal runaway and explode. Therefore, how to improve the safety of batteries has become an urgent problem to be solved.

[0029] To solve the above problems, please refer to Figures 3 - 6 shown. In the first aspect, the present application proposes an electrode tab 10, which can effectively improve the safety performance of the battery.

[0030] The pole piece 10 includes a current collector 11, an active material layer 12, and an expandable filler 14. The current collector 11 has a bearing surface 11a; the active material layer 12 is disposed on one side where the bearing surface 11a of the current collector 11 is located, and a portion to be filled is provided on the side of the active material layer 12 facing away from the bearing surface 11a; the expandable filler 14 is disposed in the portion to be filled.

[0031] The following will Figures 3 - 9 expand and introduce the specific structure of the pole piece 10.

[0032] As Figures 3 - 6 shown, the pole piece 10 includes a current collector 11, an active material layer 12, and an expandable filler 14.

[0033] As a component for collecting current in the pole piece 10, the current collector 11 mainly functions to carry the active material layer 12, collect the current generated after the chemical reaction of the active material layer 12 to form a larger current and output it externally, thereby completing the process of converting chemical energy into electrical energy.

[0034] The current collector 11 has a bearing surface 11a; among them, the bearing surface 11a can be a plane, a curved surface, or a combination of a plane and a curved surface.

[0035] As Figures 3 - 6 shown, as a component in the pole piece 10 that reacts with the electrolyte to generate current, the specific form of the active material layer 12 will be expanded and introduced below.

[0036] The active material layer 12 is disposed on one side where the bearing surface 11a of the current collector 11 is located. For example, the active material layer 12 can, but is not limited to, be covered on the bearing surface 11a of the current collector 11 by means of coating.

[0037] A portion to be filled is provided on the side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11. Among them, the portion to be filled can be a virtual structure directly formed on the side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11 and used to accommodate the expandable filler 14 and the flame retardant filler 15 (introduced below); the portion to be filled can also be a solid structure disposed on the side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11 and used to accommodate the expandable filler 14 and the flame retardant filler 15.

[0038] As a component in the pole piece 10 that is suitable for expanding when heated, the specific form of the expandable filler 14 will be expanded and introduced below.

[0039] The expandable filler 14 is disposed in the portion to be filled; the specific implementation manner of disposing the expandable filler 14 in the portion to be filled is not limited herein, and the designer can make a reasonable design according to actual needs; for example, the expandable filler 14 can be, but is not limited to, disposed in the portion to be filled by coating.

[0040] The expandable filler 14 is configured to expand by heating to squeeze the current collector 11 so that the current collector 11 generates displacement and / or deformation. For example, during the process of the expandable filler 14 disposed in the portion to be filled expanding by heating, a force acts between the expandable filler 14 and the active material layer 12 and squeezes the current collector 11, and the current collector 11 moves in a direction away from the separator 21 of the battery cell (hereinafter introduced) under the action of the squeezing force (i.e., only generates displacement); for another example, during the process of the expandable filler 14 disposed in the portion to be filled expanding by heating, a force acts between the expandable filler 14 and the active material layer 12 and squeezes the current collector 11, and the current collector 11 bends in a direction away from the separator 21 of the battery cell under the action of the squeezing force (i.e., only generates deformation); for still another example, during the process of the expandable filler 14 disposed in the portion to be filled expanding by heating, a force acts between the expandable filler 14 and the active material layer 12 and squeezes the current collector 11, and the current collector 11 moves and bends in a direction away from the separator 21 of the battery cell under the action of the squeezing force (i.e., generates displacement and deformation).

[0041] Based on the electrode sheet 10 in the embodiment of the present application, in the case where the external spike 30 pierces the separator 21 of the battery cell, by disposing the expandable filler 14 in the portion to be filled on the side of the bearing surface 11a of the active material layer 12 facing away from the current collector 11, a force acts between the expandable filler 14 and the active material layer 12 and squeezes the current collector 11 during the process of the expandable filler 14 expanding by heating, so that the current collector 11 moves and / or bends in a direction away from the separator 21 of the battery cell under the action of the squeezing force, so as to generate a gap D between the electrode sheet 10 and the separator 21 of the battery cell, reduce the possibility of short circuit formed by the contact between the positive electrode sheet 10a and the negative electrode sheet 10b, and thus reduce the occurrence of the situation that the battery explodes due to thermal runaway of the battery.

[0042] Further, as Figures 3 - 6 shown, a groove 13a is provided on the side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11, and the region surrounded by the groove wall surface of the groove 13a serves as the above-mentioned portion to be filled.

[0043] Among them, the groove 13a is a virtual structure formed on the side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11; the specific shape of the cross-section of the groove 13a in the plane passing through the thickness direction of the current collector 11 is not limited here, and designers can make reasonable designs according to actual needs. For example, the cross-section of the groove 13a in the plane passing through the thickness direction of the current collector 11 can be rectangular or conical. The number of grooves 13a can be one or more; and when the number of grooves 13a is more than one, all the grooves 13a can be the same or different in shape design and / or size design. The above-mentioned groove 13a can be processed and formed on the side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11 by, but not limited to, using a specific convex roller rolling, a specific convex flat cold pressing or laser etching and other methods to form the part to be filled. The depth dimension of the groove 13a in the thickness direction of the current collector 11 is not limited here, and designers can make reasonable designs according to actual needs, as long as the depth dimension of the groove 13a in the thickness direction of the current collector 11 is less than or equal to the thickness dimension of the active material layer 12.

[0044] By designing the part to be filled as a groove 13a directly formed on the side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11, the area surrounded by the groove wall surface of the groove 13a is used as the part to be filled to accommodate the expansible filler 14, so that it is convenient to process and form the groove 13a on the side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11.

[0045] Specifically, when the number of grooves 13a is more than one, the multiple grooves 13a can be arbitrarily distributed on the side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11, and the multiple grooves 13a are equally spaced on the side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11 according to a preset arrangement method. And when the multiple grooves 13a are equally spaced on the side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11 according to a preset arrangement method, there can be, but not limited to, the following several embodiments.

[0046] Such as Figure 3As shown, in the first embodiment, a plurality of grooves 13a are arranged in an M-row * N-column manner on one side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11. By arranging the plurality of grooves 13a in a rectangular array in an M-row * N-column manner, the expandable filling members 14 filled in the plurality of grooves 13a are also arranged in an M-row * N-column manner. In this way, during the process of thermal expansion of the plurality of expandable filling members 14 filled in the plurality of grooves 13a, a uniformly distributed acting force can be generated between the expandable filling members 14 and the active material layer 12 and the current collector 11 can be extruded, so that the current collector 11 generates displacement and / or deformation under the action of the uniformly distributed extrusion force, so that the gap D generated between the pole piece 10 and the diaphragm 21 of the battery cell is uniform, and the possibility of short circuit caused by the contact between the positive pole piece 10a and the negative pole piece 10b is further reduced, thereby further reducing the occurrence of thermal runaway of the battery and causing the battery to explode.

[0047] In the second embodiment, the plurality of grooves 13a are arranged in a circular array with any point on the surface of one side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11 as the array center. By arranging the plurality of grooves 13a in a circular array with any point on the surface of one side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11 as the array center, the expandable filling members 14 filled in the plurality of grooves 13a are also arranged in a circular array with this point as the array center. In this way, during the process of thermal expansion of the plurality of expandable filling members 14 filled in the plurality of grooves 13a, a uniformly distributed acting force can be generated between the expandable filling members 14 and the active material layer 12 and the current collector 11 can be extruded, so that the current collector 11 generates displacement and / or deformation under the action of the uniformly distributed extrusion force, so that the gap D generated between the pole piece 10 and the diaphragm 21 of the battery cell is uniform, and the possibility of short circuit caused by the contact between the positive pole piece 10a and the negative pole piece 10b is further reduced, thereby further reducing the occurrence of thermal runaway of the battery and causing the battery to explode.

[0048] Of course, when the part to be filled is a solid structure provided on one side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11 and used to accommodate the expandable filling member 14 and the flame retardant filling member 15, the part to be filled can be a plurality of (more than two) protrusions (not shown in the figure) provided on one side of the active material layer 12 facing away from the bearing surface 11a of the current collector 11. At this time, the area enclosed by the outer wall surfaces of any two protrusions can be used to accommodate the expandable filling member 14 and the flame retardant filling member 15.

[0049] Further, as Figures 3 - 6As shown, the expandable filler 14 is suitable for expansion when heated, and the specific preparation material of the expandable filler 14 is any one of polyethers, polyesters, and polyether ketones. By designing the preparation material of the expandable filler 14 to be any one of polyethers, polyesters, and polyether ketones, the raw material source is wide and easy to obtain. It should be noted that the preparation material of the expandable filler 14 is not limited to the above-mentioned polyethers, polyesters, and polyether ketones, as long as the material can expand when heated and does not chemically react with the electrolyte of the battery, it can be used as the preparation material of the expandable filler 14.

[0050] Furthermore, if Figures 7 - 9 As shown, the pole piece 10 also includes a flame retardant filler 15, which is arranged in the portion to be filled. The flame retardant filler 15 is configured to cover the surface of the active material layer 12 away from the supporting surface 11a of the current collector 11 under the action of the expandable filler 14 that expands when subjected to heat.

[0051] The specific implementation method of setting the flame retardant filler 15 in the part to be filled is not limited here, and designers can make reasonable designs according to actual needs; for example, the flame retardant filler 15 can be but is not limited to being set in the part to be filled by coating.

[0052] On the basis of arranging the expandable filler 14 in the portion to be filled, by further arranging the flame-retardant filler 15 in the portion to be filled, the flame-retardant filler 15 can cover the surface of the active material layer 12 on the side away from the supporting surface 11a of the current collector 11 under the action of the expandable filler 14 expanding due to heat, which can effectively reduce the possibility of short circuit caused by contact between the positive electrode plate 10a and the negative electrode plate 10b, thereby effectively reducing the occurrence of thermal runaway of the battery and causing battery explosion. At the same time, the flame-retardant filler 15 can also effectively reduce the internal temperature of the battery.

[0053] Specifically, it can be understood that the expandable filler 14 and the flame retardant filler 15 are both arranged in the portion to be filled, and the expandable filler 14 and the flame retardant filler 15 can be arranged in the portion to be filled arbitrarily, or in a specific arrangement. When the expandable filler 14 and the flame retardant filler 15 are arranged in the filling portion in a specific arrangement, it can be but not limited to the following embodiments.

[0054] like Figures 7 - 9As shown, in the first embodiment, the flame-retardant filler 15 is disposed farther from the bearing surface 11a of the current collector 11 than the expandable filler 14; along the thickness direction of the current collector 11, the depth of the portion to be filled is H, and the thickness of the flame-retardant filler 15 is h, and H and h satisfy the conditional formula: h / H ≤ 1 / 3. For example, the specific value of h / H can be, but is not limited to, 1 / 10, 1 / 9, 1 / 8, 1 / 7, 1 / 6, 1 / 5, 1 / 4, or 1 / 3, etc. By reasonably designing the values of the thickness h of the flame-retardant filler 15 and the depth H of the portion to be filled, the thickness h of the flame-retardant filler 15 and the depth H of the portion to be filled satisfy the above conditional formula, so that on the one hand, it can ensure that the expandable filler 14 expands when heated to generate a sufficient gap D between the electrode sheet 10 and the separator 21 of the battery cell, and on the other hand, it can ensure that the flame-retardant filler 15 covers the surface of the active material layer 12 on the side facing away from the bearing surface 11a of the current collector 11. In this way, the possibility of the positive electrode sheet 10a and the negative electrode sheet 10b coming into contact to form a short circuit can be effectively reduced, thereby effectively reducing the occurrence of the battery getting out of thermal control and causing the battery to explode.

[0055] In the second embodiment, the flame-retardant filler 15 and the expandable filler 14 are arranged in a left-right symmetric manner in the portion to be filled.

[0056] Furthermore, as Figures 7 - 9 shown, the preparation material of the flame-retardant filler 15 is any one of silicon dioxide, aluminum oxide, titanium dioxide, tungsten trioxide, and zinc oxide. By designing the preparation material of the flame-retardant filler 15 to be any one of silicon dioxide, aluminum oxide, titanium dioxide, tungsten trioxide, and zinc oxide, the raw material sources are wide and easy to obtain.

[0057] It should be noted that the preparation material of the flame-retardant filler 15 is not limited to the above-mentioned silicon dioxide, aluminum oxide, titanium dioxide, tungsten trioxide, and zinc oxide; as long as it does not chemically react with the electrolyte of the battery and can prevent or block the combustion of the battery. It can be understood that for the flame-retardant filler 15 with different preparation materials, the specific flame-retardant action modes of the flame-retardant filler 15 are also different, and can be, but are not limited to, endothermic action, covering action, inhibition of chain reaction action, and non-combustible gas asphyxiation action, which will not be elaborated here.

[0058] Please refer to Figures 10 - 12 shown, in the second aspect, the embodiment of the present application provides a battery cell (not shown in the figure), and this battery cell includes the above-mentioned electrode sheet 10, and the electrode sheet 10 is at least one of a positive electrode sheet 10a and a negative electrode sheet 10b.

[0059] For example, as Figure 10As shown, the battery cell in the embodiment of the present application may include at least one of the above-mentioned electrode plates 10, and all of these electrode plates 10 serve as the positive electrode plates 10a of the battery cell. At this time, the battery cell may further include at least one other electrode plate with a structure different from the above-mentioned electrode plate 10 as the negative electrode plate of the battery cell, and a separator 21 (a sub-component of the battery cell) is provided between all the positive electrode plates 10a of the battery cell and all the negative electrode plates of the battery cell. At this time, when the external spike 30 pierces the separator 21 of the battery cell, during the process of the expandable filler 14 expanding due to heat, a force is generated between the expandable filler 14 and the active material layer 12 and the current collector 11 is squeezed, so that the current collector 11 moves and / or bends in a direction deviating from the separator 21 of the battery cell under the action of the squeezing force, so as to generate a gap D1 between the positive electrode plate 10a and the separator 21 of the battery cell.

[0060] For another example, as Figure 11 shown, it may also be that the battery cell in the embodiment of the present application includes at least one of the above-mentioned electrode plates 10, and all of these electrode plates 10 serve as the negative electrode plates 10b of the battery cell. At this time, the battery cell may further include at least one other electrode plate with a structure different from the above-mentioned electrode plate 10 as the positive electrode plate of the battery cell, and a separator 21 (a sub-component of the battery cell) is provided between all the negative electrode plates 10b of the battery cell and all the positive electrode plates of the battery cell. At this time, when the external spike 30 pierces the separator 21 of the battery cell, during the process of the expandable filler 14 expanding due to heat, a force is generated between the expandable filler 14 and the active material layer 12 and the current collector 11 is squeezed, so that the current collector 11 moves and / or bends in a direction deviating from the separator 21 of the battery cell under the action of the squeezing force, so as to generate a gap D2 between the negative electrode plate 10b and the separator 21 of the battery cell.

[0061] For another example, as Figure 12 shown, it may also be that the battery cell in the embodiment of the present application includes a plurality (more than two) of the above-mentioned electrode plates 10, where some of the electrode plates 10 serve as the positive electrode plates 10a of the battery cell, and the remaining electrode plates 10 serve as the negative electrode plates 10b of the battery cell. A separator 21 (a sub-component of the battery cell) is provided between all the positive electrode plates 10a of the battery cell and all the negative electrode plates 10b of the battery cell. At this time, when the external spike 30 pierces the separator 21 of the battery cell, during the process of the expandable filler 14 expanding due to heat, a force is generated between the expandable filler 14 and the active material layer 12 and the current collector 11 is squeezed, so that the current collector 11 moves and / or bends in a direction deviating from the separator 21 of the battery cell under the action of the squeezing force, so as to generate a gap D1 between the positive electrode plate 10a and the separator 21 of the battery cell and a gap D2 between the negative electrode plate 10b and the separator 21 of the battery cell.

[0062] Based on the battery cell in the embodiment of the present application, having the above-mentioned electrode plate 10, it is possible to reduce the possibility of short circuit formed by the contact between the positive electrode plate 10a and the negative electrode plate 10b, thereby reducing the occurrence of the situation where the battery undergoes thermal runaway and causes the battery to explode.

[0063] In a third aspect, an embodiment of the present application provides a battery (not shown in the figure), which includes a housing, an electrolyte, and the above-described battery cell. The housing has a receiving cavity, the electrolyte is poured into the receiving cavity of the housing, and the above-described battery cell is disposed in the receiving cavity of the housing.

[0064] Based on the battery in the embodiment of the present application, having the above-described battery cell, it is possible to reduce the possibility of the positive electrode plate 10a and the negative electrode plate 10b coming into contact to form a short circuit, thereby reducing the occurrence of thermal runaway of the battery resulting in battery explosion, so as to improve the safety performance of the battery.

[0065] In a fourth aspect, an embodiment of the present application provides an electrical device (not shown in the figure), which includes a housing and the above-described battery. The housing has a battery mounting groove, and the above-described battery is mounted in the housing corresponding to the battery mounting groove.

[0066] It should be noted that the electrical device is a device capable of converting the electrical energy of the above-described battery into other forms of energy; for example, the electrical device can be, but is not limited to, terminals such as mobile phones, tablets, and computers; for another example, the electrical device can also be, but is not limited to, lighting devices such as flashlights, table lamps, and voice-activated lights; for yet another example, the electrical device can further be, but is not limited to, timing devices such as electronic watches and electronic clocks.

[0067] Based on the electrical device in the embodiment of the present application, having the above-described battery, it is possible to reduce the possibility of the positive electrode plate 10a and the negative electrode plate 10b coming into contact to form a short circuit, thereby reducing the occurrence of thermal runaway of the battery resulting in battery explosion, so as to improve the safety performance of the electrical device.

[0068] In the drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components; in the description of the present application, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and cannot be understood as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0069] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included within the protection scope of the present application.

Claims

1. A pole piece, characterized in that, Comprising: A current collector having a bearing surface; An active material layer disposed on one side of the current collector where the bearing surface is located, and a portion to be filled is provided on the side of the active material layer facing away from the bearing surface; An expandable filler disposed in the portion to be filled.

2. The electrode sheet according to claim 1, wherein A groove is provided on the side of the active material layer facing away from the bearing surface, and the region surrounded by the groove wall surface serves as the portion to be filled.

3. The electrode sheet according to claim 2, wherein The number of the grooves is multiple, and all the grooves are equally spaced on the side of the active material layer facing away from the bearing surface according to a preset arrangement pattern.

4. The electrode sheet according to claim 3, wherein The preparation material of the expandable filler is any one of polyethers, polyesters, and polyether ketones.

5. The electrode sheet according to any one of claims 1-4, wherein The electrode sheet further includes a flame-retardant filler disposed in the portion to be filled; wherein the flame-retardant filler is configured to cover the surface of the side of the active material layer facing away from the bearing surface under the action of the expandable filler that expands when heated.

6. The pole piece according to claim 5, characterized in that, The flame-retardant filler is farther away from the bearing surface than the expandable filler; In the thickness direction of the current collector, the depth of the portion to be filled is H, and the thickness of the flame-retardant filler is h, and H and h satisfy the conditional formula: h / H ≤ 1 / 3.

7. The electrode sheet according to claim 5, wherein The preparation material of the flame-retardant filler is any one of silicon dioxide, aluminum oxide, titanium dioxide, tungsten trioxide, and zinc oxide.

8. A battery cell, characterized in that, Comprising: The electrode sheet according to any one of claims 1-7, and the electrode sheet is at least one of a positive electrode sheet and a negative electrode sheet.

9. A battery, characterized in that, Comprising: A housing having an accommodation cavity; The battery cell according to claim 8, and the battery cell is disposed in the accommodation cavity; and An electrolyte is poured into the accommodation cavity.

10. An electrical device, characterized in that, Comprising: A housing having a battery installation groove; and The battery according to claim 9, and the battery is installed in the housing corresponding to the battery installation groove.

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