Electrode assembly, battery and electric equipment

Abstract

The utility model belongs to the technical field of batteries, and discloses an electrode assembly, a battery and electric equipment. The electrode assembly comprises a winding core and an insulating sheet. The winding core is provided with a center hole extending in the first direction. The insulation sheet comprises a main body sheet and an extension sheet, the main body sheet is located in the center hole, a capillary channel is arranged on one surface, facing the inner wall of the center hole, of the main body sheet, and the extension sheet is connected to one end, in the first direction, of the main body sheet and attached to at least part of the outer wall of the roll core. According to the electrode assembly, the capillary channels are formed in the insulating sheet, the free electrolyte is adsorbed into the center hole of the roll core through the capillary action, it is guaranteed that the electrolyte is evenly distributed, the problems that the electrolyte absorbed in the center hole is insufficient, and the infiltration effect is poor are effectively solved, and therefore the service life of the electrode assembly is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to an electrode assembly, a battery and an electrical device. Background Art

[0002] As the main power source for new energy vehicles, the safety and service life of power batteries are attracting more and more attention. Usually, power batteries include aluminum shells, winding cores, electrolytes, insulating sheets and top covers. The insulating sheets play the role of insulation isolation, and the top cover is used to seal the aluminum shell. The winding core is infiltrated with electrolyte, and the electrolyte is continuously consumed during the battery cycle. Usually, in order to extend the service life of the battery, a certain volume of free electrolyte is set inside the battery to replenish the consumed electrolyte.

[0003] In actual applications, there is often a problem that the electrolyte inside the core is less than other parts, and the free electrolyte is unevenly infiltrated, so the core cannot be fully infiltrated. The free electrolyte has a poor infiltration effect on the core, which will affect the service life of the battery.

[0004] Therefore, it is urgent to propose an electrode assembly, a battery and an electrical device with good free electrolyte infiltration effect to solve the above problems. Utility Model Content

[0005] One purpose of the utility model is to provide an electrode assembly, in which the electrolyte of the electrode assembly is evenly distributed and the electrolyte infiltration effect in the central hole of the winding core is good.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] An electrode assembly, comprising:

[0008] A winding core having a central hole extending along a first direction;

[0009] An insulating sheet, comprising a main sheet and an extension sheet, wherein the main sheet is located in the center hole, a capillary channel is provided on a surface of the main sheet facing the inner wall of the center hole, and the extension sheet is connected to one end of the main sheet in the first direction and adheres to at least a portion of the outer wall of the winding core.

[0010] Optionally, the main body sheet includes a first sheet and a second sheet, the cross-section of the second sheet is serrated, the first sheet and the second sheet are stacked and connected, the capillary channel is formed between the first sheet and the second sheet, and the second sheet faces the inner wall of the center hole.

[0011] Optionally, a plurality of convex ridges extending along the first direction are arranged on the main body sheet, and strip grooves are formed between adjacent convex ridges, and the strip grooves form the capillary channels.

[0012] Optionally, the main sheet includes a sheet body and a plurality of tubular structures, the plurality of tubular structures all extend along the first direction and are fixedly connected to the sheet body, and the tubular structures form the capillary channels.

[0013] Optionally, the capillary channel has dimensions less than 1 mm in both the width direction and the thickness direction of the winding core.

[0014] Optionally, the winding core has a corner and a flat surface, and a protrusion is formed on the surface of the insulating sheet located in the corner area.

[0015] Optionally, an adhesive layer is provided at the inner side of the corner, and the adhesive layer bonds the corner and the insulating sheet.

[0016] Optionally, the flow rate of the capillary channel in the corner area is greater than the flow rate of the capillary channel in the flat surface area.

[0017] Another object of the utility model is to provide a battery, in which the electrolyte is evenly distributed, the electrolyte infiltration effect in the central hole of the winding core is good, and the battery has a long service life.

[0018] To achieve this purpose, the utility model adopts the following technical solutions:

[0019] A battery comprises the above electrode assembly.

[0020] Another object of the utility model is to provide an electrical device having a longer working life.

[0021] To achieve this purpose, the utility model adopts the following technical solutions:

[0022] An electrical device comprises the battery mentioned above.

[0023] Beneficial effects:

[0024] The electrode assembly provided by the utility model is provided with an insulating sheet, which includes a main sheet located in the central hole of the winding core and an extension sheet attached to the outer wall of the winding core, the main sheet plays an insulating and isolating role for the inner wall of the central hole of the winding core, and the extension sheet plays an insulating and isolating role for the outer wall of the winding core. By providing a capillary channel on the insulating sheet, the free electrolyte is adsorbed into the central hole of the winding core by capillary action, ensuring uniform distribution of the electrolyte, effectively alleviating the problem of insufficient absorption of electrolyte in the central hole and poor infiltration effect, thereby helping to increase the service life of the electrode assembly.

[0025] The battery provided by the utility model includes the above-mentioned electrode assembly. By arranging a capillary channel on the insulating sheet in the central hole of the winding core, the electrolyte is absorbed into the central hole of the winding core, so that the electrode assembly is fully and evenly infiltrated, which can effectively extend the service life of the battery.

[0026] The electric device provided by the utility model comprises the above-mentioned battery. The battery in the electric device has a long service life, so the electric device has a long working life. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0028] Figure 1 This is an assembly structure diagram of a winding core and an insulating sheet provided in Embodiment 1 of the present utility model;

[0029] Figure 2 This is a schematic diagram of the structure of the insulating sheet provided in the first embodiment of the utility model in the unfolded state;

[0030] Figure 3 It is a cross-sectional schematic diagram of an insulating sheet provided in Embodiment 1 of the present utility model;

[0031] Figure 4 It is a cross-sectional schematic diagram of an insulating sheet provided in Embodiment 2 of the present utility model;

[0032] Figure 5 It is a cross-sectional schematic diagram of the insulating sheet provided in the third embodiment of the present utility model.

[0033] In the figure:

[0034] 100, insulating sheet; 110, main body sheet; 111, first sheet body; 112, second sheet body; 113, ridge; 120, extension sheet; 130, insertion hole; 140, insertion sheet; 200, winding core. DETAILED DESCRIPTION

[0035] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0036] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature include the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0039] Embodiment 1

[0040] See also Figure 1 and Figure 2 This embodiment provides an electrode assembly, including a winding core 200 and an insulating sheet 100. The winding core 200 has a central hole extending along a first direction. The insulating sheet 100 includes a main sheet 110 and an extension sheet 120, the main sheet 110 is located in the central hole, a capillary channel is provided on one side of the main sheet 110 facing the inner wall of the central hole, and the extension sheet 120 is connected to one end of the main sheet 110 in the first direction and is attached to at least a portion of the outer wall of the winding core 200.

[0041] The electrode assembly provided in this embodiment is provided with an insulating sheet 100, and the insulating sheet 100 includes a main sheet 110 located in the center hole of the core 200 and an extension sheet 120 attached to the outer wall of the core 200. The main sheet 110 plays an insulating and isolating role for the inner wall of the center hole of the core 200, and the extension sheet 120 plays an insulating and isolating role for the outer wall of the core 200. The main sheet 110 is arranged in the center hole of the core 200, which can better insulate the core and prevent the problem of the core short circuit caused by the shrinkage of the inner layer diaphragm of the core. However, since the main sheet 110 is arranged in the center hole of the core, the inner wall of the center hole cannot absorb the permeated electrolyte, which affects the electrochemical reaction of the inner layer of the core. By arranging a capillary channel on the insulating sheet 100, the free electrolyte is adsorbed into the center hole of the core 200 by capillary action, ensuring uniform distribution of the electrolyte, effectively alleviating the problem of insufficient absorption of electrolyte in the center hole and poor wetting effect, thereby helping to increase the service life of the electrode assembly.

[0042] Further, see Figure 2 The main body sheet 110 is roughly rectangular in the unfolded state, and its length is set according to the size of the inner wall of the center hole of the winding core 200. Optionally, in the unfolded state, the main body sheet 110 is provided with a plug 140 and a socket 130 at both ends of its length direction, and the plug 140 and the socket 130 are plugged in. The main body sheet 110 is connected by plugging the plug 140 and the socket 130, which can prevent the main body sheet 110 from deforming and shrinking during battery assembly and use, resulting in insulation failure. The structural design is very simple and the assembly operation is also very convenient. Of course, in other embodiments, the main body sheet 110 can also be connected by bonding or clamping.

[0043] Further, two extension sheets 120 are provided, and the two extension sheets 120 are respectively attached to the two straight surfaces of the core 200, and the distance between the two extension sheets 120 is greater than or equal to the thickness of the core 200. In this embodiment, the core 200 includes two relatively straight surfaces and a curved surface connecting the two straight surfaces. Two sets of pole tabs are provided on the core 200, and the two sets of pole tabs are provided at the same end of the core 200. The end of the extension sheet 120 connected to the main sheet 110 is located at the end of the core 200 without the pole tab, and the end of the extension sheet 120 away from the main sheet 110 is close to the end of the core 200 with the pole tab. On the one hand, it can avoid interference between the extension sheet 120 and the pole tab; on the other hand, the pole tab generates a lot of heat during the charging and discharging process, so as to avoid the extension sheet 120 from melting due to excessive temperature. Optionally, the end of the extension sheet 120 away from the main sheet 110 is rounded to avoid the edge of the extension sheet 120 scratching the cell diaphragm and causing a short circuit inside the battery.

[0044] Furthermore, the extension sheet 120 is provided with a fold, and the distance between the fold and the main sheet 110 is equal to half the thickness of the core 200. It can be understood that after the core 200 is wound on the insulating sheet 100, the extension sheet 120 is bent to make the extension sheet 120 close to the outer wall of the core 200. Therefore, by providing a fold on the extension sheet 120, the extension sheet 120 can be easily bent, and the extension sheet 120 located at the bottom of the core 200 can be more closely attached to the core 200.

[0045] Further, the size of the capillary channel in the width direction and thickness direction of the core 200 is less than 1 mm. Exemplarily, the size of the capillary channel in the width direction and thickness direction of the core 200 can be 0.95 mm, 0.9 mm, 0.85 mm, 0.8 mm, 0.75 mm or 0.7 mm, etc. The size of the capillary channel in the width direction can be the same as the size in the thickness direction, or it can be different. Optionally, the capillary channel is arranged along the axial direction of the central hole, and the cross-sectional area of ​​the capillary channel can be circular, square or semicircular, etc.

[0046] See also Figure 3 In the present embodiment, the main body sheet 110 includes a first sheet 111 and a second sheet 112, the cross section of the second sheet 112 is serrated, the first sheet 111 and the second sheet 112 are stacked and connected, a capillary channel is formed between the first sheet 111 and the second sheet 112, and the second sheet 112 faces the inner wall of the central hole. Optionally, the first sheet 111 and the second sheet 112 are bonded and connected by a colloid. Optionally, the sawtooth can be a square tooth or a trapezoidal tooth. In other embodiments, the cross section of the second sheet 112 can also be a wave-shaped. The present embodiment does not specifically limit the cross-sectional shape of the second sheet 112, as long as the capillary channel can be formed after the first sheet 111 and the second sheet 112 are bonded.

[0047] Furthermore, the core 200 has corners and flat surfaces, and a protrusion is formed on the surface of the insulating sheet 100 located at the corner area. It can be understood that the core 200 will be pressed into a flat shape after winding, so the core 200 has a flat surface and a corner. Since the thickness of the insulating sheet 100 at the protrusion is relatively thick, it can support the corner area and prevent the corner area of ​​the core 200 from being deformed due to pressure or impact. Optionally, the number of protrusions can be one or more, and the cross-sectional shape of the protrusion can be circular, strip-shaped, or wavy, etc.

[0048] Furthermore, an adhesive layer is provided inside the corner, and the adhesive layer bonds the corner to the insulating sheet 100. By bonding the corner area to the insulating sheet 100, it is possible to effectively prevent the corner area from losing powder when the winding core 200 is put into the shell or hit. Optionally, the adhesive layer is formed by coating an insulating glue.

[0049] Furthermore, the flow rate of the capillary channel in the corner area is greater than the flow rate of the capillary channel in the plane area. The corner area has a larger curvature and a tighter structure. It is an area where the stress of the winding core is concentrated. Therefore, the corner area is not easy to absorb electrolyte, and lithium ions are difficult to embed, which easily leads to lithium precipitation. By increasing the flow rate of the capillary channel in the corner area, the electrolyte infiltration in the corner area can be promoted, the dead corner of liquid absorption can be prevented, and the electrolyte distribution in the center hole can be ensured to be uniform. Optionally, the pore size of the capillary channel in the corner area is larger than the pore size of the capillary channel on the flat surface, and the corner area can absorb more electrolyte and obtain good infiltration; optionally, the number of capillary channels in the corner area is more than the number of capillary channels on the flat surface. Under the same area, the number of capillary channels in the corner area is greater, and more electrolyte is absorbed and infiltrated.

[0050] Furthermore, the present embodiment also provides a battery, including the above-mentioned electrode assembly. By providing a capillary channel on the insulating sheet 100 in the center hole of the winding core 200, the electrolyte is absorbed into the center hole of the winding core 200, so that the electrode assembly is fully and evenly infiltrated, which can effectively extend the service life of the battery. In the embodiment of the present application, the battery may be a secondary battery, which refers to a battery that can be used continuously by activating the active material by charging after the battery is discharged. The battery may be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc., which is not limited in the embodiment of the present application. As an example, the battery may be a cylindrical battery, a prismatic battery, a soft-pack battery or a battery of other shapes, and the prismatic battery includes a square shell battery, a blade-shaped battery, a polygonal prismatic battery, and the polygonal prismatic battery is, for example, a hexagonal prismatic battery, etc., which is not particularly limited in the present application. The battery mentioned in the embodiment of the present application refers to a single physical module including one or more batteries to provide higher voltage and capacity. In some embodiments, the battery may be a battery module. When there are multiple batteries, multiple batteries are arranged and fixed to form a battery module. In some embodiments, the battery may be a battery pack, which includes a box and batteries, and the batteries or battery modules are accommodated in the box.

[0051] Furthermore, the present embodiment also provides an electrical device, including the above-mentioned battery. The battery in the electrical device has a long service life, so the electrical device has a long service life. Multiple batteries can directly power the electrical device, or they can form a power supply device in parallel, series or mixed connection, such as a battery module, to power various electrical devices in the form of a power supply device. The electrical device can be in various forms, for example, a mobile phone, a portable device, a laptop computer, a battery car, an electric car, a ship, a spacecraft, an electric toy, an electric tool or various household appliances, etc. For example, a spacecraft includes an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0052] Embodiment 2

[0053] The similarities between this embodiment and the first embodiment are not described in detail. The following only describes the similarities between this embodiment and the first embodiment.

[0054] See also Figure 4 In this embodiment, a plurality of ridges 113 extending along a first direction are provided on the main body sheet 110, and strip grooves are formed between adjacent ridges 113, and the strip grooves form capillary channels. It can be understood that the interval length between adjacent ridges 113 is less than 1 mm, thereby ensuring that the strip grooves can produce capillary action. The cross-sectional shape of the ridges 113 can be square, circular, semicircular, etc., which is not specifically limited here. Optionally, the interval between the ridges 113 in the corner area of ​​the core 200 is greater than the interval between the ridges 113 in the plane area, thereby ensuring that the capillary channel flow in the corner area is larger and avoiding the formation of dead corners in the corner area.

[0055] Embodiment 3

[0056] The similarities between this embodiment and the first embodiment are not described in detail. The following only describes the similarities between this embodiment and the first embodiment.

[0057] See also Figure 5 In this embodiment, the main sheet 110 includes a sheet body and a plurality of tubular structures, the plurality of tubular structures all extend along a first direction and are fixedly connected to the sheet body, and the tubular structures form capillary channels. Optionally, the cross-section of the tubular structure may be circular, semicircular, or square, etc. Optionally, the diameter of the tubular structure in the corner area of ​​the winding core 200 is larger than the diameter of the tubular structure in the plane area, thereby ensuring that the capillary channel flow in the corner area is larger and avoiding the formation of dead corners in the corner area.

[0058] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of protection of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. An electrode assembly, characterized in that: include: A winding core (200), wherein the winding core (200) has a central hole extending along a first direction; An insulating sheet (100), the insulating sheet (100) comprising a main sheet (110) and an extension sheet (120), the main sheet (110) being located in the central hole, a capillary channel being provided on a surface of the main sheet (110) facing the inner wall of the central hole, the extension sheet (120) being connected to one end of the main sheet (110) in the first direction and being attached to at least a portion of the outer wall of the winding core (200).

2. The electrode assembly according to claim 1, characterized in that: The main body sheet (110) comprises a first sheet body (111) and a second sheet body (112); the cross section of the second sheet body (112) is serrated; the first sheet body (111) and the second sheet body (112) are stacked and connected; the capillary channel is formed between the first sheet body (111) and the second sheet body (112); the second sheet body (112) faces the inner wall of the central hole.

3. The electrode assembly according to claim 1, characterized in that: The main body sheet (110) is provided with a plurality of ridges extending along the first direction, and strip grooves are formed between adjacent ridges, and the strip grooves form the capillary channels.

4. The electrode assembly according to claim 1, characterized in that: The main sheet (110) comprises a sheet body and a plurality of tubular structures, wherein the plurality of tubular structures extend along the first direction and are fixedly connected to the sheet body, and the tubular structures form the capillary channels.

5. The electrode assembly according to claim 1, characterized in that: The dimensions of the capillary channel in the width direction and the thickness direction of the winding core (200) are both less than 1 mm.

6. The electrode assembly according to claim 1, characterized in that: The winding core (200) has a corner and a flat surface, and a protrusion is formed on the surface of the insulating sheet (100) located in the corner area.

7. The electrode assembly according to claim 6, characterized in that: An adhesive layer is provided at the inner side of the corner, and the adhesive layer bonds the corner and the insulating sheet.

8. The electrode assembly according to claim 7, characterized in that: The flow rate of the capillary channel in the corner area is greater than the flow rate of the capillary channel in the flat surface area.

9. A battery, characterized in that Comprising the electrode assembly as described in any one of claims 1-8.

10. An electrical device, characterized in that: Comprising the battery as claimed in claim 9.

Images