Electrode assembly, energy storage device and electric device

Abstract

The application discloses an electrode assembly, an energy storage device and an electric equipment, and relates to the technical field of energy storage. The electrode assembly comprises a plurality of pole piece units, the pole piece unit comprises a positive pole piece, a negative pole piece and a diaphragm piece, and the diaphragm piece is arranged between the positive pole piece and the negative pole piece; the negative pole piece comprises a body part and a protruding part, the protruding part is formed on at least part of the edge part of the body part, and the protruding part protrudes towards one side of the positive pole piece; wherein the orthographic projection of the positive pole piece on the positive pole piece is located in the body part, and in the direction perpendicular to the large surface of the negative pole piece, the distance between the end part of the protruding part away from the body part and the surface of the body part is greater than the distance between the positive pole piece and the surface of the body part.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and more specifically, to an electrode assembly, an energy storage device, and an electrical appliance. Background Technology

[0002] Secondary batteries, also known as rechargeable batteries or storage batteries, are batteries that can be recharged after being discharged, allowing the active materials to be reactivated and reused. Their recyclable nature has made them a primary power source for electrical equipment.

[0003] As the demand for rechargeable batteries gradually increases, people are also placing higher demands on their performance in all aspects, especially on battery safety. The safety of electrode components is a crucial factor affecting battery safety. Summary of the Invention

[0004] A primary objective of this application is to provide an electrode assembly that improves the safety of the electrode assembly.

[0005] To achieve the above-mentioned objectives, this application adopts the following technical solution:

[0006] According to one aspect of this application, an electrode assembly is provided, comprising: a plurality of electrode units, each electrode unit including a positive electrode, a separator, and a negative electrode, wherein the separator is disposed between the positive electrode and the negative electrode; the negative electrode includes a body portion and a first protrusion portion, wherein the first protrusion portion is formed on at least a portion of the edge portion of the body portion, and the first protrusion portion protrudes toward one side of the positive electrode.

[0007] Wherein, the orthogonal projection of the positive electrode on the negative electrode is located within the body portion, and in the direction perpendicular to the large surface of the negative electrode, the distance between the end of the first protrusion away from the body portion and the surface of the body portion is greater than the distance between the positive electrode and the opposing surfaces of the body portion.

[0008] The electrode assembly provided in this application has a first protrusion formed on at least a portion of the edge of the body of the negative electrode. The orthogonal projection of the positive electrode onto the negative electrode is located within the body. In the direction perpendicular to the large surface of the negative electrode, the distance between the end of the first protrusion away from the body and the surface of the body is greater than the distance between the positive electrode and the facing surfaces of the body. That is, the positive electrode has a first protrusion on its side, which improves the alignment between the positive and negative electrodes. This reduces the requirement for the negative electrode to exceed the size of the positive electrode, resulting in a smaller overall size of the electrode assembly, a higher energy density, reduced risk of lithium ion deposition, and improved safety of the electrode assembly.

[0009] According to one embodiment of this application, the first protrusion is formed on two opposite edge portions of the body portion along a first direction.

[0010] The electrode assembly provided in this application further improves the alignment effect between the positive and negative electrode plates by forming first protrusions on two opposite edges of the body portion, with the positive electrode plate located between the two opposite first protrusions. This further reduces the requirement for the negative electrode plate to exceed the size of the positive electrode plate, resulting in a smaller overall size of the electrode assembly and a higher energy density. At the same time, the first protrusions can absorb lithium ions migrating from the side of the positive electrode plate, further reducing the risk of lithium ion precipitation.

[0011] According to one embodiment of this application, in a second direction perpendicular to the first direction, the lengths of the first protrusions on the two opposite edges are both greater than or equal to the length of the positive electrode sheet.

[0012] The electrode assembly provided in this application, by making the length of the first protrusion greater than or equal to the length of the positive electrode, can better absorb lithium ions migrating from the side of the positive electrode, and further reduce the risk of lithium ion precipitation.

[0013] According to one embodiment of this application, in a second direction perpendicular to the first direction, the length of the body portion is greater than the length of the positive electrode sheet, and the length of the first protrusion on the two opposite edge portions is the same as the length of the body portion.

[0014] The electrode assembly provided in this application, by making the length of the body portion greater than the length of the positive electrode sheet, and the length of the first protrusion on the two opposite edge portions the same as the length of the body portion, that is, the length of the first protrusion is greater than the length of the positive electrode sheet, can better absorb lithium ions migrating from the side of the positive electrode sheet, and further reduce the risk of lithium ion precipitation.

[0015] According to one embodiment of this application, in the first direction, two opposing first protrusions have opposing first inclined walls, and the first inclined walls of the two first protrusions respectively form an obtuse angle with a first angle on the side of the body portion near the center region of the body portion.

[0016] In the first direction, the positive electrode sheet and the first protrusion have second inclined walls on their opposite sides, which are respectively arranged facing the corresponding first inclined wall. The two second inclined walls form an obtuse angle with the second angle of the positive electrode sheet on the side closer to the center region of the positive electrode sheet.

[0017] The electrode assembly provided in this application has a groove with a gradually expanding opening formed on the negative electrode sheet through the first inclined wall, which cooperates with the second inclined walls on both sides of the positive electrode sheet in the first direction. This achieves the alignment between the positive and negative electrode sheets, which further reduces the requirement for the negative electrode sheet to exceed the size of the positive electrode sheet, resulting in a smaller overall size of the electrode assembly, a higher energy density of the electrode assembly, and a reduced risk of lithium ion deposition.

[0018] According to one embodiment of this application, in a second direction perpendicular to the first direction, the two opposite ends of the diaphragm are respectively formed with first blocking portions, the first blocking portions being located on the side of the diaphragm facing the positive electrode plate; the two opposite first blocking portions have opposing third inclined walls, and the third inclined walls of the two first blocking portions are respectively obtuse angles with the third angle of the diaphragm near the central region of the diaphragm.

[0019] In the second direction, fourth inclined walls are formed on both sides of the positive electrode sheet, which are arranged facing the corresponding first blocking portion. The two fourth inclined walls form an obtuse angle with the fourth angle on the side of the positive electrode sheet closer to the center region of the positive electrode sheet.

[0020] The electrode assembly provided in this application forms a third inclined wall at each of the opposite ends of the separator and a fourth inclined wall on each of the two sides of the positive electrode, thereby achieving mutual alignment between the separator and the positive electrode and the negative electrode. This reduces the requirement for the negative electrode to exceed the size of the positive electrode, resulting in a smaller overall size of the electrode assembly, a higher energy density, and a reduced risk of lithium ion deposition.

[0021] According to one embodiment of this application, a plurality of electrode units are stacked along a third direction perpendicular to the large surface of the electrode unit, and a diaphragm is provided between adjacent electrode units, and the diaphragm between adjacent electrode units is connected to the diaphragm of the plurality of electrode units.

[0022] The electrode assembly provided in this application achieves insulation between adjacent electrode units by continuously bending and folding the diaphragm sheet.

[0023] According to one embodiment of this application, along a first direction, the first protrusion is formed on two opposite edge portions of the body portion; in a second direction perpendicular to the first direction, second blocking portions are formed at opposite ends of the diaphragm between adjacent electrode units, the second blocking portions being located between the diaphragm and the negative electrode; the two opposing second blocking portions have opposing fifth inclined walls, and the fifth inclined walls of the two second blocking portions form an obtuse angle with the fifth angle of the diaphragm near the center region of the diaphragm.

[0024] In the second direction, a sixth inclined wall is formed on each side of the negative electrode sheet, which is arranged facing the corresponding fifth inclined wall. The angle between the two sixth inclined walls and the sixth inclined wall on the side of the negative electrode sheet closer to the center region of the negative electrode sheet is an obtuse angle.

[0025] The electrode assembly provided in this application has a fifth inclined wall of the second blocking part, and sixth inclined walls that are respectively formed on both sides of the negative electrode sheet and are arranged facing the corresponding fifth inclined wall. This achieves the alignment of the separator sheet and the negative electrode sheet, thereby reducing the requirement for the negative electrode sheet to exceed the size of the positive electrode sheet, making the overall size of the electrode assembly smaller, the energy density of the electrode assembly higher, and reducing the risk of lithium ion deposition.

[0026] According to one embodiment of this application, the diaphragm sheet includes a first sub-diaphragm sheet and a second sub-diaphragm sheet; in two adjacent electrode units, one is provided with the first sub-diaphragm sheet and the other is provided with the second sub-diaphragm sheet; or, one side of the negative electrode sheet is the first sub-diaphragm sheet and the opposite side is the second sub-diaphragm sheet.

[0027] The electrode assembly provided in this application achieves insulation between the negative electrode and the positive electrode through a first sub-diaphragm and a second sub-diaphragm.

[0028] According to one embodiment of this application, the negative electrode in the plurality of electrode units is a continuous negative electrode connected together; or, the positive electrode in the plurality of electrode units is a continuous positive electrode connected together.

[0029] The electrode assembly provided in this application improves the electrical performance of the negative electrode by making the negative electrode in the multiple electrode units a continuous negative electrode connected together; and improves the electrical performance of the positive electrode by making the positive electrode in the multiple electrode units a continuous positive electrode connected together.

[0030] According to one embodiment of this application, the negative electrode further includes a second protrusion, and the second protrusion is formed on at least a portion of the edge of the body portion along a first direction, the second protrusion protruding toward the side opposite to the positive electrode.

[0031] The electrode assembly provided in this application, through the second protrusion, enables the positive electrode of one of the two adjacent electrode units to form an alignment effect on both sides in the thickness direction. That is, one side is aligned through the groove of its own negative electrode, and the other side is aligned through the groove of another electrode unit, thereby improving the alignment effect of the electrode units and reducing the risk of lithium ion deposition.

[0032] According to one embodiment of this application, the first protrusion and the second protrusion are symmetrically arranged on the body portion.

[0033] The electrode assembly provided in this application, by symmetrically arranging the first protrusion and the second protrusion on the body, enables the diaphragm between adjacent electrode units to be better aligned, thereby improving the alignment effect.

[0034] According to one embodiment of this application, along a first direction, two opposing edge portions of the body portion are respectively formed with second protrusions, and the two opposing second protrusions have opposing seventh inclined walls, and the seventh inclined walls of the two second protrusions are respectively obtuse angles with the seventh angle on the side of the body portion near the center region of the body portion.

[0035] In the first direction, the positive electrode sheet and the second protrusion have opposite sides formed with eighth inclined walls that are arranged opposite to the corresponding seventh inclined walls. The two eighth inclined walls form an obtuse angle with the eighth inclined wall on the side of the positive electrode sheet closer to the center region of the positive electrode sheet.

[0036] The electrode assembly provided in this application achieves alignment between the positive and negative electrode plates by using the seventh inclined wall on the two opposite edges of the main body and the eighth inclined wall on the positive electrode plate that is disposed opposite to the seventh inclined wall.

[0037] According to one embodiment of this application, the body portion includes a negative electrode body and a positive electrode coating located on the surface of the negative electrode body, wherein the first protrusion is made of the same material as the positive electrode coating, and / or the second protrusion is made of the same material as the positive electrode coating.

[0038] The electrode assembly provided in this application, by making the first protrusion and / or the second protrusion the same material as the positive electrode coating, facilitates the formation of the protrusion. When the positive electrode coating is applied to the negative electrode body, the protrusion can be formed simultaneously, avoiding the need for excessive raw materials and process steps. On the other hand, it improves the absorption effect of lithium ions migrating from the side of the positive electrode and reduces the risk of lithium ion precipitation.

[0039] According to one embodiment of this application, in the two electrode units located at both ends of the electrode assembly, the negative electrode in one electrode unit does not have the first protrusion on the surface near the periphery of the electrode assembly, and the negative electrode in the other electrode unit does not have the second protrusion on the surface near the periphery of the electrode assembly.

[0040] The electrode assembly provided in this application has a first protrusion on the surface of the negative electrode near the periphery of the electrode assembly in one electrode unit and a second protrusion on the surface of the negative electrode near the periphery of the electrode assembly in the other electrode unit, so that the upper and lower surfaces of the electrode assembly are flat without protrusions, thereby ensuring the stability of the diaphragms on the upper and lower sides of the electrode assembly.

[0041] According to another aspect of this application, an energy storage device is provided, comprising: a housing, a top cover, and the aforementioned electrode assembly, wherein the housing includes a receiving cavity with an opening, the electrode assembly is housed within the receiving cavity, and the top cover seals the opening of the housing.

[0042] The energy storage device provided in this application has a first protrusion formed on at least a portion of the edge of the body of the negative electrode in the electrode assembly. The orthogonal projection of the positive electrode on the negative electrode is located inside the body. In the direction perpendicular to the large surface of the negative electrode, the distance between the end of the first protrusion away from the body and the surface of the body is greater than the distance between the positive electrode and the facing surfaces of the body. That is, the positive electrode has a first protrusion on its side, which makes the alignment between the positive electrode and the negative electrode better. This reduces the requirement for the negative electrode to exceed the size of the positive electrode, resulting in a smaller overall size of the electrode assembly, a higher energy density of the electrode assembly, a reduced risk of lithium ion deposition, and improved safety of the energy storage device.

[0043] According to another aspect of this application, an electrical device is provided, the electrical device including the energy storage device described in the preceding aspect, the energy storage device supplying power to the electrical device.

[0044] The electrical device provided in this application has a first protrusion formed on at least a portion of the edge of the negative electrode body of the electrode assembly in the energy storage device. The orthogonal projection of the positive electrode on the negative electrode is located inside the body. In the direction perpendicular to the large surface of the negative electrode, the distance between the end of the first protrusion away from the body and the surface of the body is greater than the distance between the positive electrode and the facing surfaces of the body. That is, the positive electrode has a first protrusion on its side, which makes the alignment between the positive electrode and the negative electrode better. This reduces the requirement for the negative electrode to exceed the size of the positive electrode, resulting in a smaller overall size of the electrode assembly, a higher energy density of the electrode assembly, a reduced risk of lithium ion deposition, and improved safety of the electrical device.

[0045] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0046] The above and other features and advantages of this application will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0047] Figure 1 A schematic diagram of a residential energy storage system provided for one embodiment of this disclosure.

[0048] Figure 2 This is a schematic diagram of an electrode unit provided for one embodiment of the present disclosure.

[0049] Figure 3This is a schematic diagram of a positive electrode and a negative electrode provided for one embodiment of the present disclosure.

[0050] Figure 4 This is a top view of a negative electrode sheet provided for one embodiment of the present disclosure.

[0051] Figure 5 for Figure 4 Cross-sectional view of surface AA.

[0052] Figure 6 for Figure 4 Cross-sectional view of the BB surface.

[0053] Figure 7 A top view of a diaphragm sheet provided for one embodiment of this disclosure.

[0054] Figure 8 In one implementation method Figure 7 Cross-sectional view of the C-plane.

[0055] Figure 9 In another implementation method Figure 7 Cross-sectional view of the C-plane.

[0056] Figure 10 This is a top view of a positive electrode sheet provided for one embodiment of the present disclosure.

[0057] Figure 11 for Figure 10 Cross-sectional view of the DD plane.

[0058] Figure 12 for Figure 10 Cross-sectional view of the EE surface.

[0059] Figure 13 This is a diagram illustrating the stacking process of an electrode assembly provided in one embodiment of the present disclosure.

[0060] Figure 14 for Figure 13 Electrode assemblies formed by the provided lamination process.

[0061] Figure 15 A stacking process diagram of an electrode assembly provided for another embodiment of this disclosure.

[0062] Figure 16 for Figure 15 Electrode assemblies formed by the provided lamination process.

[0063] Figure 17 This is a stacking process diagram of an electrode assembly provided for yet another embodiment of the present disclosure.

[0064] Figure 18 for Figure 17 Electrode assemblies formed by the provided lamination process.

[0065] Figure 19 This is a stacking process diagram of an electrode assembly provided for another embodiment of the present disclosure.

[0066] Figure 20 This is a schematic diagram of an electrode assembly provided for one embodiment of the present disclosure.

[0067] The reference numerals in the attached figures are explained as follows:

[0068] 10. Energy storage devices; 20. Power conversion devices; 30. User loads;

[0069] 100, Electrode unit; 110, Positive electrode; 111, Second inclined wall; 112, Fourth inclined wall; 113, Eighth inclined wall; 114, Tenth inclined wall; 120, Negative electrode; 121, Body portion; 122, First protrusion; 1220, First inclined wall; 123, Second protrusion; 1230, Seventh inclined wall; 124, Sixth inclined wall; 125, Ninth inclined wall; 130, Diaphragm; 131, First blocking portion; 1310, Third inclined wall; 132, Second blocking portion; 1320, Fifth inclined wall; 133, First sub-diaphragm; 134, Second sub-diaphragm;

[0070] 200. Stacking table;

[0071] A1, First included angle; A2, Second included angle; A3, Third included angle; A4, Fourth included angle; A5, Fifth included angle; A6, Sixth included angle; A7, Seventh included angle; A8, Eighth included angle; A9, Ninth included angle; A10, Tenth included angle. Detailed Implementation

[0072] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0073] Because the energy we need is highly time- and space-dependent, in order to utilize energy rationally and improve its efficiency, we need a medium or device to store one form of energy in the same way or by converting it into another, and then release it in a specific energy form based on future application needs. As we all know, to achieve the major goal of carbon neutrality, the current main approach is to replace fossil fuels with green energy to generate green electricity.

[0074] Currently, green energy mainly includes solar energy, wind energy, and hydropower. However, solar and wind energy generally suffer from strong intermittency and large fluctuations, which can cause voltage instability in the green power grid (insufficient electricity during peak demand and excessive electricity during off-peak demand). Unstable voltage can damage the power grid, and therefore may lead to the problem of "curtailment of wind and solar power" due to insufficient electricity demand or insufficient grid capacity.

[0075] To solve the problem of insufficient electricity demand or inadequate grid capacity, we must rely on energy storage devices. These devices convert electrical energy into other forms of energy through physical or chemical means and store it. When needed, the stored energy is converted back into electrical energy and released. Simply put, an energy storage device is like a large "power bank," storing electrical energy when solar and wind power are abundant and releasing it when required.

[0076] Current energy storage applications are quite widespread, including generation-side energy storage, grid-side energy storage, renewable energy grid-connected energy storage, and user-side energy storage. The corresponding types of energy storage devices include:

[0077] (1) Large energy storage containers used in grid-side energy storage scenarios can serve as high-quality active and reactive power regulation power sources in the grid, enabling load matching of electrical energy in time and space, enhancing the absorption capacity of renewable energy, and playing a significant role in grid system backup, alleviating peak load power supply pressure, and peak regulation and frequency regulation.

[0078] (2) Small and medium-sized energy storage cabinets used in commercial and industrial energy storage scenarios (banks, shopping malls, etc.) and small household energy storage boxes used in residential energy storage scenarios primarily operate under the "peak shaving and valley filling" mode. Because there are significant price differences in electricity consumption during peak and off-peak periods, users with energy storage devices typically charge the cabinets / boxes during off-peak hours to reduce costs; during peak hours, they release the stored electricity for use, thus saving on electricity bills. Furthermore, in remote areas and regions prone to natural disasters such as earthquakes and hurricanes, the existence of household energy storage devices effectively provides backup power for users and the power grid, eliminating the inconvenience caused by frequent power outages due to disasters or other reasons.

[0079] This explanation will take the residential energy storage scenario in user-side energy storage as an example. Figure 1A residential energy storage system is illustrated, comprising an energy storage device 10, a power conversion device 20 (such as a photovoltaic panel), and user loads 30 (such as streetlights, household appliances, etc.). The energy storage device 10 is a small energy storage box that can be wall-mounted to an outdoor wall. Specifically, the power conversion device 20 can convert solar energy into electrical energy during periods of low electricity prices and store it in the energy storage device 10, then supply it to the user loads 30 during peak electricity prices, or supply it to the user loads 30 during power outages / power interruptions.

[0080] In conjunction with the aforementioned energy storage methods using physical or electrochemical means, taking electrochemical energy storage as an example, the energy storage device 10 includes at least one set of chemical batteries. The chemical elements within these batteries serve as the energy storage medium, and the charging and discharging process is achieved through the chemical reactions or changes in the storage medium. Simply put, electrical energy generated from solar or wind power is stored in at least one set of chemical batteries through the chemical reactions or changes in the storage medium. When external power consumption reaches its peak, the stored energy is released through the chemical reactions or changes in the storage medium for use, or transferred to areas with power shortages.

[0081] This application provides an energy storage device, which may be, but is not limited to, a single battery cell, a battery module, a battery pack, or a battery system. The single battery cell may be a lithium-ion secondary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, etc., and may be flat, cuboid, etc.; this application does not limit the specific form of the single battery cell.

[0082] The energy storage device may include a housing and an electrode assembly. The housing has a receiving cavity in which the electrode assembly is housed. The housing may be a cylindrical structure open at one end, in which case the energy storage device includes an end cap assembly to seal one opening of the housing. Alternatively, the housing may be a cylindrical structure open at both ends, in which case the energy storage device includes an end cap assembly and a cover plate, or two end cap assemblies, such that one end cap assembly and a cover plate, or two end cap assemblies, can respectively seal the two openings of the housing.

[0083] The end cap assembly includes an end cap body and electrode terminals. The electrode terminals are installed on the end cap body, with one end connected to the electrode assembly and the other end exposed outside the housing to serve as an output terminal of the energy storage device. The end cap body is equipped with an explosion-proof valve and a liquid injection hole. The explosion-proof valve is used to discharge gas from the housing cavity to improve the safety of the energy storage device. The liquid injection hole is used to inject electrolyte into the housing cavity of the energy storage device.

[0084] The electrode assembly can be a stacked electrode assembly, which includes multiple stacked electrode units. Each stacked electrode unit includes a positive electrode, a negative electrode, and a separator sheet stacked together. A separator sheet is provided between the positive electrode and the negative electrode. The ends of the positive electrode and the negative electrode have tabs to form the positive and negative tabs of the energy storage device. The positive and negative tabs can be located at the same end of the electrode assembly or at different ends of the electrode assembly. When the positive and negative tabs are located at the same end of the electrode assembly, they are connected to the positive and negative terminals of the end cap assembly, respectively, so as to realize the output of electrical energy of the electrode assembly through the positive and negative terminals. When the positive and negative tabs are located at both ends of the electrode assembly, one of the positive and negative tabs is connected to the electrode terminal of the end cap assembly, and the other is connected to the bottom of the housing or the electrode terminal of another end cap assembly, so as to realize the output of electrical energy of the electrode assembly through the electrode terminal of the end cap assembly and the bottom of the housing, or through the electrode terminals of the two end cap assemblies.

[0085] It should be noted that the energy storage device may also include a current collector, which can be used to connect one tab of the electrode assembly to one electrode terminal of the end cap assembly, and to connect the other tab of the electrode assembly to the bottom of the housing.

[0086] In existing stacked electrode assemblies, when the separator and positive and negative electrodes are stacked together, the positioning of the separator-positive electrode-separator-negative electrode relationship needs to be considered to ensure that the size of the positive and negative electrodes is larger than the minimum size of the negative electrode, so that the lithium ions migrating from the positive electrode can be completely absorbed by the negative electrode. When the size of the positive and negative electrodes is about the same, lithium ions are easily deposited, which can puncture the separator and cause a short circuit inside the electrode assembly, thus posing a fire risk.

[0087] This application provides an electrode assembly, such as... Figure 2 As shown, the electrode assembly includes: a plurality of electrode units 100, each electrode unit 100 including a positive electrode 110, a negative electrode 120 and a separator 130, with the separator 130 provided between the positive electrode 110 and the negative electrode 120; the negative electrode 120 includes a body portion 121 and a first protrusion 122, the first protrusion 122 being formed on at least a portion of the edge of the body portion 121, the first protrusion 122 protruding toward the side facing the positive electrode 110; wherein, the orthogonal projection of the positive electrode 110 onto the negative electrode 120 is located within the body portion 121, and in the direction Z perpendicular to the large surface of the negative electrode 120, the distance H1 between the end of the first protrusion 122 away from the body portion 121 and the surface of the body portion 121 is greater than the distance H2 between the opposing surfaces of the positive electrode 110 and the body portion 121.

[0088] The electrode assembly provided in this application has a first protrusion 122 formed on at least a portion of the edge of the body portion 121 of the negative electrode 120. The orthogonal projection of the positive electrode 110 onto the negative electrode 120 is located within the body portion 121. In the direction Z perpendicular to the large surface of the negative electrode 120, the distance between the end of the first protrusion 122 away from the body portion 121 and the surface of the body portion 121 is greater than the distance between the facing surfaces of the positive electrode 110 and the body portion 121. That is, the side of the negative electrode 120 is provided with the first protrusion 122, which improves the alignment between the positive electrode 110 and the negative electrode 120. This reduces the requirement for the portion of the negative electrode 120 that exceeds the size of the positive electrode 110, resulting in a smaller overall size of the electrode assembly, a higher energy density of the electrode assembly, and a reduced risk of lithium ion deposition.

[0089] In one embodiment, such as Figure 2 and Figure 3 As shown, along the first direction X, first protrusions 122 are formed on two opposite edges of the body portion 121. By forming first protrusions 122 on two opposite edges of the body portion 121, the positive electrode 110 is located between the two opposite first protrusions 122, further improving the alignment effect between the positive electrode 110 and the negative electrode 120. This further reduces the size requirement of the negative electrode 120 for the portion exceeding the size of the positive electrode 110, resulting in a smaller overall size of the electrode assembly and a higher energy density. At the same time, the first protrusions 122 can absorb lithium ions migrating from the side of the positive electrode 110, further reducing the risk of lithium ion deposition.

[0090] In this configuration, when multiple stacked electrode units 100 are connected as a continuous electrode unit, the first direction X is the connection direction of the continuous stack. Positioning the first protrusion 122 in the connection direction of the continuous stack does not affect the tabs at the ends of the negative electrode 120 and the positive electrode 110 in the second direction Y. The continuous electrode unit consists of multiple electrode units 100 connected together by continuous positive electrode 110 or negative electrode 120. These multiple positive electrode 110 or negative electrode 120 are continuously folded along their length to form a stacked continuous electrode unit, thereby improving the electrical performance of the electrode unit 100 by connecting the multiple electrode units 100 together through the positive electrode 110 or negative electrode 120.

[0091] In one embodiment, such as Figure 2 and Figure 4As shown, in the second direction Y, which is perpendicular to the first direction X, the lengths of the first protrusions 122 on the two opposite edges are both greater than or equal to the length of the positive electrode 110. By making the lengths of the first protrusions 122 greater than or equal to the length of the positive electrode 110, lithium ions migrating from the sides of the positive electrode 110 can be better absorbed, further reducing the risk of lithium ion precipitation.

[0092] In the second direction Y, the length of the body portion 121 is greater than the length of the positive electrode 110, and the lengths of the first protrusions 122 on the two opposite edge portions are the same as the length of the body portion 121. By making the length of the body portion 121 greater than the length of the positive electrode 110, and the lengths of the first protrusions 122 on the two opposite edge portions the same as the length of the body portion 121, that is, the lengths of the first protrusions 122 are all greater than the length of the positive electrode 110, the absorption of lithium ions migrating from the side of the positive electrode 110 can be better achieved, further reducing the risk of lithium ion precipitation.

[0093] In one embodiment, such as Figure 5 As shown, in the first direction X, two opposing first protrusions 122 have opposing first inclined walls 1220. The first inclined walls 1220 of the two first protrusions 122 are obtuse angles A1 with the first part of the body 121 near the center region of the body 121, that is, the two first protrusions 122 form a groove with a gradually widening opening; as shown Figure 10 and Figure 12 As shown, in the first direction X, second inclined walls 111 are formed on both sides of the positive electrode 110 and the first protrusion 122 facing each other. The two second inclined walls 111 are arranged facing the two first inclined walls 1220. The two second inclined walls 111 are obtuse angles with the second included angle A2 on the side of the positive electrode 110 near the center region of the positive electrode 110, that is, the opposing second inclined walls 111 and the first inclined walls 1220 have an intersecting portion. The negative electrode 120 forms a groove with a gradually widening opening through the first inclined walls 1220 on both sides. This groove cooperates with the recessed portion formed by the second inclined walls 111 on both sides of the positive electrode 110 in the first direction X, realizing the alignment between the positive electrode 110 and the negative electrode 120. This further reduces the size requirement of the negative electrode 120 for the portion exceeding the size of the positive electrode 110, resulting in a smaller overall size of the electrode assembly, a higher energy density of the electrode assembly, and a reduced risk of lithium ion deposition.

[0094] The angles of the first included angle A1 and the second included angle A2 can be the same or substantially the same, so that the first inclined wall 1220 and the second inclined wall 111 are set in parallel or substantially parallel, which is more conducive to the alignment between the positive electrode 110 and the negative electrode 120.

[0095] In one embodiment, such as Figure 7 and Figure 8As shown, in the second direction Y, first blocking portions 131 are formed at opposite ends of the diaphragm 130, and the first blocking portions 131 are located on the side of the diaphragm 130 facing the positive electrode plate 110; the two opposing first blocking portions 131 have opposing third inclined walls 1310, and the third inclined walls 1310 of the two first blocking portions 131 are obtuse angles A3 with the third angle A3 on the side of the diaphragm 130 near the center region of the diaphragm 130. Figure 10 and Figure 11 As shown, in the second direction Y, the positive electrode 110 has a fourth inclined wall 112 formed on both sides. The two fourth inclined walls 112 are respectively arranged facing the corresponding first blocking part 131. The two fourth inclined walls 112 are obtuse angles with the fourth included angle A4 on the side of the positive electrode 110 near the center region of the positive electrode 110. That is, the third inclined wall 1310 and the fourth inclined wall 112 arranged opposite to each other have an intersecting part.

[0096] By forming third inclined walls 1310 at opposite ends of the separator 130 and fourth inclined walls 112 on both sides of the positive electrode 110, the interlacing of the third inclined walls 1310 and the fourth inclined walls 112 achieves mutual alignment between the separator 130 and the positive electrode 110, thereby achieving alignment with the negative electrode 120. This reduces the size requirement of the negative electrode 120 over the positive electrode 110, resulting in a smaller overall size of the electrode assembly, higher energy density, and reduced risk of lithium-ion deposition. The angles of the third included angle A3 and the fourth included angle A4 can be the same or substantially the same, ensuring that the third inclined walls 1310 and the fourth inclined walls 112 are parallel or substantially parallel, which further facilitates the alignment between the positive electrode 110 and the negative electrode 120.

[0097] In one embodiment, such as Figure 14As shown, the diaphragm sheets 130 in the multiple electrode units 100 are continuous diaphragm sheets 130 connected together. Adjacent electrode units 100 have diaphragm sheets 130 between them. The multiple electrode units 100 are stacked along a third direction perpendicular to the large surface of the electrode unit 100. The diaphragm sheets 130 between adjacent electrode units 100 are connected to the diaphragm sheets 130 in the multiple electrode units 100. By continuously bending and folding the diaphragm sheets 130, diaphragm sheets 130 are also formed between adjacent electrode units 100, achieving insulation between adjacent electrode units 100. The third direction is perpendicular to the first direction X and the second direction Y, that is, the stacking direction of the electrode units 100 is perpendicular to the large surface of the electrode unit 100. By having the stacking direction of the multiple electrode units 100 perpendicular to the large surface of the electrode unit 100, the space occupied by the stacked multiple electrode units 100 can be minimized. The large surface of the electrode unit 100 can be considered as the surface with the largest area of ​​the electrode unit 100. Furthermore, the large surface of the electrode unit 100 can be considered as the surface that generates the most heat. For example, when the electrode unit 100 is square, the electrode unit 100 includes two opposing large surfaces.

[0098] Independent diaphragms 130 can also be provided between adjacent electrode units 100, that is, the diaphragms 130 in multiple electrode units 100 can be non-continuous diaphragms 130.

[0099] In one embodiment, such as Figure 9 and Figure 14 As shown, in the second direction Y, the two opposite ends of the diaphragm 130 between adjacent electrode units 100 are respectively formed with second blocking portions 132, and the second blocking portions 132 are located on the side of the diaphragm 130 near the negative electrode 120. The two opposing second blocking portions 132 have opposing fifth inclined walls 1320, and the fifth inclined walls 1320 of the two second blocking portions 132 are respectively obtuse angles A5 with the fifth angle on the side of the diaphragm 130 near the central region of the diaphragm 130.

[0100] Among them, such as Figure 6 As shown, in the second direction Y, the negative electrode 120 has a sixth inclined wall 124 formed on both sides. The two sixth inclined walls 124 are arranged facing the corresponding fifth inclined wall 1320. The two sixth inclined walls 124 are obtuse angles with the sixth angle A6 on the side of the negative electrode 120 near the center area of ​​the negative electrode 120. That is, the fifth inclined wall 1320 and the sixth inclined wall 124 arranged opposite to each other have an intersecting part.

[0101] By forming fifth inclined walls 1320 at opposite ends of the separator 130 and sixth inclined walls 124 on both sides of the negative electrode 120, the fifth inclined walls 1320 and the sixth inclined walls 124 are staggered to align the separator 130 and the negative electrode 120. This reduces the size requirement of the negative electrode 120 over the positive electrode 110, resulting in a smaller overall size of the electrode assembly, higher energy density, and reduced risk of lithium-ion deposition. The fifth included angle A5 and the sixth included angle A6 can be the same or substantially the same, ensuring that the fifth inclined walls 1320 and the sixth inclined walls 124 are parallel or substantially parallel, which further facilitates the alignment between the separator 130 and the negative electrode 120.

[0102] The first blocking portion 131 and the second blocking portion 132 can be coatings formed on the separator. The coatings can be, for example, ceramic coatings, insulating coatings, etc. The insulating coatings can further enhance the insulation effect on the positive electrode and the negative electrode. Of course, the materials of the first blocking portion 131 and the second blocking portion 132 can be the same or different, and this application does not limit this.

[0103] In one embodiment, such as Figure 5 As shown, the negative electrode 120 also includes a second protrusion 123. The second protrusion 123 is formed on at least a portion of the edge of the body portion 121, and the second protrusion 123 protrudes toward the side opposite to the positive electrode 110. Through the second protrusion 123, in two adjacent electrode units 100, the positive electrode 110 of one electrode unit 100 has an alignment effect on both sides in the thickness direction. That is, one side is aligned through the groove of its own negative electrode 120, and the other side is aligned through the groove of the other electrode unit 100. This improves the alignment effect of the stacked electrode units 100, thereby reducing the risk of lithium ion deposition.

[0104] The first protrusion 122 and the second protrusion 123 are symmetrically arranged on the body portion 121. This symmetrical arrangement of the first protrusion 122 and the second protrusion 123 on the body portion 121 allows for better alignment of the diaphragm sheets 130 between adjacent electrode units 100, improving the alignment effect. Of course, the first protrusion 122 and the second protrusion 123 can also be asymmetrically arranged on the body portion 121; this application does not impose any restrictions on this arrangement.

[0105] Among them, such as Figure 5As shown, along the first direction X, two opposite edge portions of the body portion 121 are respectively formed with second protrusions 123, and the two opposite second protrusions 123 have opposing seventh inclined walls 1230. The seventh inclined walls 1230 of the two second protrusions 123 are obtuse angles with the seventh angle A7 on the side of the body portion 121 near the center region of the body portion 121. In the first direction X, on the two sides of the adjacent positive electrode 110 facing the second protrusions 123, eighth inclined walls 113 are respectively formed facing the corresponding seventh inclined walls 1230. The two eighth inclined walls 113 are obtuse angles with the eighth angle A8 on the side of the positive electrode 110 near the center region of the positive electrode 110.

[0106] By forming seventh inclined walls 1230 at opposite ends of the body portion 121 and eighth inclined walls 113 on both sides of the positive electrode 110, the seventh inclined walls 1230 and the eighth inclined walls 113 cooperate to align the positive electrode 110 and the negative electrode 120. This reduces the size requirement of the negative electrode 120 over the positive electrode 110, resulting in a smaller overall size of the electrode assembly, higher energy density, and reduced risk of lithium-ion deposition. The seventh included angle A7 and the eighth included angle A8 can be the same or substantially the same, so that the seventh inclined walls 1230 and the eighth inclined walls 113 are arranged parallel or substantially parallel, which further facilitates the alignment between the positive electrode 110 and the negative electrode 120.

[0107] Specifically, in the second direction Y, which is perpendicular to the first direction X, the lengths of the second protrusions 123 on the two opposite edges are both greater than or equal to the length of the positive electrode 110. By making the lengths of the second protrusions 123 greater than or equal to the length of the positive electrode 110, lithium ions migrating from the sides of the positive electrode 110 can be better absorbed, further reducing the risk of lithium ion precipitation.

[0108] In the second direction Y, the length of the body portion 121 is greater than the length of the positive electrode 110, and the lengths of the second protrusions 123 on the two opposite edge portions are the same as the length of the body portion 121. By making the length of the body portion 121 greater than the length of the positive electrode 110, and the lengths of the second protrusions 123 on the two opposite edge portions the same as the length of the body portion 121, that is, the lengths of the second protrusions 123 are all greater than the length of the positive electrode 110, the absorption of lithium ions migrating from the side of the positive electrode 110 can be better achieved, further reducing the risk of lithium ion precipitation.

[0109] In one embodiment, such as Figure 6As shown, along the second direction Y, a ninth inclined wall 125 is also formed on the edge of the negative electrode 120 facing the positive electrode 110. The two ninth inclined walls 125 are obtuse angles with the ninth angle A9 on the side of the negative electrode 120 near the center region of the negative electrode 120. The ninth inclined wall 125 forms an alignment part, which facilitates alignment with the corresponding inclined wall structure on the subsequent diaphragm 130.

[0110] In one embodiment, such as Figure 11 As shown, along the second direction Y, a tenth inclined wall 114 is also formed on the edge of the positive electrode 110 facing the negative electrode 120. The two tenth inclined walls 114 are obtuse angles with the tenth angle A10 on the side of the positive electrode 110 near the center region of the positive electrode 110. The tenth inclined wall 114 forms an alignment part, which facilitates alignment with the corresponding inclined wall structure on the subsequent separator 130.

[0111] Among them, the angles of the first included angle A1, the second included angle A2, the third included angle A3, the fourth included angle A4, the fifth included angle A5, the sixth included angle A6, the seventh included angle A7, the eighth included angle A8, the ninth included angle A9, and the tenth included angle A10 can be the same or substantially the same. When multiple electrode units 100 are stacked, the alignment between the positive electrode 110 and the negative electrode 120 can be better achieved, making the portion of the negative electrode 120 that exceeds the size of the positive electrode 110 even smaller. This results in a smaller overall size of the electrode assembly, a higher energy density of the electrode assembly, and further reduces the risk of lithium plating in the energy storage device.

[0112] In one embodiment, the body portion 121 includes a positive electrode body and a positive electrode coating on the surface of the positive electrode body, and the first protrusion 122 is made of the same material as the positive electrode coating. By making the first protrusion 122 the same material as the positive electrode coating, on the one hand, it facilitates the formation of the first protrusion 122. When the positive electrode coating is applied to the positive electrode body, the first protrusion 122 can be formed simultaneously, avoiding the need for excessive raw materials and process steps; on the other hand, it improves the absorption effect of lithium ions migrating from the side of the positive electrode 110, reducing the risk of lithium ion precipitation.

[0113] The first protrusion 122 and the positive electrode coating can be an integral structure. The first protrusion 122 and the positive electrode coating are made of the same material and can be formed using the same raw materials and processes, which improves the connection strength between the first protrusion 122 and the positive electrode coating, thereby enhancing the reliability of the electrode assembly. The first protrusion 122 can also be a ceramic coating or an insulating coating disposed on the surface of the positive electrode body; this application does not impose any limitations on this.

[0114] In one embodiment, the second protrusion 123 is made of the same material as the positive electrode coating. By making the second protrusion 123 the same material as the positive electrode coating, on the one hand, it facilitates the formation of the second protrusion 123. When the positive electrode coating is applied to the positive electrode body, the second protrusion 123 can be formed simultaneously, avoiding the need for excessive raw materials and process steps. On the other hand, it improves the absorption effect of lithium ions migrating from the side of the positive electrode 110, reducing the risk of lithium ion precipitation.

[0115] The second protrusion 123 and the positive electrode coating can be an integral structure. The second protrusion 123 and the positive electrode coating are made of the same material and can be formed using the same raw materials and processes, which improves the connection strength between the second protrusion 123 and the positive electrode coating, thereby enhancing the reliability of the electrode assembly. The second protrusion 123 can also be a ceramic coating or an insulating coating disposed on the surface of the positive electrode body; this application does not impose any limitations on this.

[0116] In one embodiment, such as Figure 14 As shown, the diaphragm sheets 130 in the multiple electrode units 100 are continuous diaphragm sheets 130 connected together, and there are diaphragm sheets 130 between adjacent electrode units 100. By continuously bending and folding the diaphragm sheets 130, diaphragm sheets 130 are also formed between adjacent electrode units 100, thereby achieving insulation between adjacent electrode units 100.

[0117] Specifically, such as Figure 13 As shown, in the formation of Figure 14 When assembling the electrode assembly as shown, step S11 may first provide a diaphragm 130; step S12 then forms a negative electrode 120 having a first protrusion 122 and a second protrusion 123 on the diaphragm 130, with the diaphragm 130 aligned with the sixth inclined wall 124 on the negative electrode 120 via the second blocking portion 132; step S13 then folds back the diaphragm 130 so that the diaphragm 130 is located on both sides of the negative electrode 120; step S14 then forms a positive electrode 110 on the diaphragm 130, with the positive electrode 110 aligned with the first protrusion 122 of the negative electrode 120 via the second inclined wall 111, and the positive electrode 110 aligned with the first blocking portion 131 of the diaphragm 130 via the fourth inclined wall 112; step S15 then folds back the diaphragm 130 to form the diaphragm 130 of the next electrode unit 100; repeating steps S11 to S15 above, to form as shown Figure 14 The electrode assembly shown includes multiple electrode units 100.

[0118] In one embodiment, such as Figure 16 As shown, the diaphragm 130 includes a first sub-diaphragm 133 and a second sub-diaphragm 134. One side of the negative electrode 120 is the first sub-diaphragm 133, and the other side is the second sub-diaphragm 134.

[0119] Specifically, such as Figure 15 As shown, in the formation of Figure 16 When assembling the electrode assembly as shown, step S21 may first provide a second sub-diaphragm 134; step S22 then forms a negative electrode 120 having a first protrusion 122 and a second protrusion 123 on the second sub-diaphragm 134, the second sub-diaphragm 134 being aligned with the sixth inclined wall 124 on the negative electrode 120 via the second blocking portion 132; step S23 then forms a first sub-diaphragm 133 on the negative electrode 120, the first sub-diaphragm 133 and the second sub-diaphragm 134 being aligned with the second sub-diaphragm 120. The separator 134 is located on both sides of the negative electrode 120; step S24 then forms the positive electrode 110 on the first sub-separator 133, the positive electrode 110 is aligned with the first protrusion 122 of the negative electrode 120 through the second inclined wall 111, and the positive electrode 110 is aligned with the first blocking portion 131 of the second sub-separator 134 through the fourth inclined wall 112; step S25 then folds back the first sub-separator 133; repeating the above steps S21 to S25, forming as shown Figure 16 The electrode assembly shown includes multiple electrode units 100.

[0120] Among them, such as Figure 16 As shown, the negative electrode 120 in the multiple electrode units 100 is a continuous negative electrode 120 connected together. By making the negative electrode 120 in the multiple electrode units 100 a continuous negative electrode 120 connected together, the electrical performance of the negative electrode 120 in the electrode assembly is improved.

[0121] In one embodiment, such as Figure 18 As shown, the diaphragm 130 includes a first sub-diaphragm 133 and a second sub-diaphragm 134. In two adjacent electrode units 100, one is provided with the first sub-diaphragm 133 and the other is provided with the second sub-diaphragm 134.

[0122] Specifically, such as Figure 17 As shown, in the formation of Figure 18When assembling the electrode assembly as shown, step S31 may first provide a first sub-diaphragm sheet 133 and a second sub-diaphragm sheet 134; step S32 then forms a negative electrode sheet 120 having a first protrusion 122 and a second protrusion 123 on the first sub-diaphragm sheet 133, with the first sub-diaphragm sheet 133 aligned with the sixth inclined wall 124 on the negative electrode sheet 120 via the second blocking portion 132; step S33 then folds back the first sub-diaphragm sheet 133, forming a first sub-diaphragm sheet 133 on the opposite side of the negative electrode sheet 120. The separator 133 is located on both sides of the negative electrode 120; in step S34, a positive electrode 110 is formed on the first sub-separator 133. The positive electrode 110 is aligned with the first protrusion 122 of the negative electrode 120 through the second inclined wall 111, and the positive electrode 110 is aligned with the first blocking portion 131 of the first sub-separator 133 through the fourth inclined wall 112; in step S34, the second sub-separator 134 is folded back to serve as the separator 130 of the next electrode unit 100; steps S31 to S35 are repeated to form the following... Figure 16 The electrode assembly shown includes multiple electrode units 100.

[0123] Among them, such as Figure 18 As shown, the positive electrode 110 in the plurality of electrode units 100 is a continuous negative electrode 120 connected together. By making the positive electrode 110 in the plurality of electrode units 100 a continuous positive electrode 110 connected together, the electrical performance of the positive electrode 110 in the electrode assembly is improved.

[0124] In one embodiment, such as Figure 19 As shown, during the stacking process to form the electrode unit 100, a stacking platform 200 is provided that matches the structure of the separator and the negative electrode 120, enabling the bottom separator and the negative electrode 120 to be aligned relative to the stacking platform 200, thereby improving the subsequent stacking effect. The stacking platform 200 may, for example, have a boss corresponding to a groove on the negative electrode 120 to achieve initial alignment and fixation of the electrode.

[0125] In one embodiment, such as Figure 20 As shown, referring to region F of the two electrode units 100 located at both ends of the electrode assembly, the negative electrode 120 in one electrode unit 100 does not have a first protrusion 122 on its surface near the periphery of the electrode assembly, and the negative electrode 120 in the other electrode unit 100 does not have a second protrusion 123 on its surface near the periphery of the electrode assembly. This ensures that both the upper and lower surfaces of the electrode assembly are flat without protrusions, thereby guaranteeing the stability of the diaphragms on both sides of the electrode assembly.

[0126] This application also provides an electrical device, which may be an energy storage device, a vehicle, an energy storage container, etc. The electrical device includes the energy storage device described in the above embodiments, and the energy storage device supplies power to the electrical device. The electrical device provided in this application has a first protrusion 122 formed on at least a portion of the edge of the body portion 121 of the negative electrode 120 of the electrode assembly in the energy storage device. The orthogonal projection of the positive electrode 110 on the negative electrode 120 is located within the body portion 121. In the direction Z perpendicular to the large surface of the negative electrode 120, the distance between the end of the first protrusion 122 away from the body portion 121 and the surface of the body portion 121 is greater than the distance between the facing surfaces of the positive electrode 110 and the body portion 121. That is, the positive electrode 110 has a first protrusion 122 on its side, which makes the positive electrode 110 and the negative electrode 120 better aligned. This reduces the requirement for the negative electrode 120 to exceed the size of the positive electrode 110, resulting in a smaller overall size of the electrode assembly, a higher energy density of the electrode assembly, reduced risk of lithium ion deposition, and improved safety of the electrical device.

[0127] In the embodiments of this application, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise expressly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0128] In the description of the embodiments of the application, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the application and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the application.

[0129] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the claims. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0130] The above are merely preferred embodiments of the application examples and are not intended to limit the application examples. For those skilled in the art, the application examples can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the application examples should be included within the protection scope of the application examples.

Claims

1. An electrode assembly, characterized in that, include: Multiple electrode units (100) are provided, each electrode unit (100) including a positive electrode (110), a negative electrode (120) and a separator (130), wherein the separator (130) is provided between the positive electrode (110) and the negative electrode (120); the negative electrode (120) includes a body portion (121) and a first protrusion portion (122), wherein the first protrusion portion (122) is formed on at least a portion of the edge portion of the body portion (121), and the first protrusion portion (122) protrudes toward one side of the positive electrode (110); Wherein, the orthogonal projection of the positive electrode (110) onto the negative electrode (120) is located within the body portion (121), and in the direction perpendicular to the large surface of the negative electrode (120), the distance between the end of the first protrusion (122) away from the body portion (121) and the surface of the body portion (121) is greater than the distance between the facing surfaces of the positive electrode (110) and the body portion (121); Along the first direction, the two opposite edge portions of the body portion (121) are respectively formed with the first protrusion (122); in the first direction, the two opposite first protrusions (122) have opposing first inclined walls (1220), and the first inclined walls (1220) of the two first protrusions (122) are obtuse angles with the first included angle (A1) of the body portion (121) near the center region of the body portion (121); in the first direction, the positive electrode plate (110) and the two sides opposite to the first protrusions (122) are respectively formed with second inclined walls (111) facing the corresponding first inclined walls (1220), and the two second inclined walls (111) are obtuse angles with the second included angle (A2) of the positive electrode plate (110) near the center region of the positive electrode plate (110).

2. The electrode assembly according to claim 1, characterized in that, In a second direction perpendicular to the first direction, the length of the first protrusion (122) on the two opposite edges is greater than or equal to the length of the positive electrode (110).

3. The electrode assembly according to claim 1, characterized in that, In a second direction perpendicular to the first direction, the length of the body portion (121) is greater than the length of the positive electrode plate (110), and the length of the first protrusion (122) on the two opposite edge portions is the same as the length of the body portion (121).

4. The electrode assembly according to claim 1, characterized in that, In a second direction perpendicular to the first direction, the diaphragm (130) has a first blocking portion (131) formed at opposite ends. The first blocking portion (131) is located on the side of the diaphragm (130) facing the positive electrode (110). The two opposing first blocking portions (131) have opposing third inclined walls (1310). The third inclined walls (1310) of the two first blocking portions (131) have an obtuse angle (A3) with the third angle (A3) of the diaphragm (130) on the side near the center region of the diaphragm (130). In the second direction, the positive electrode (110) has a fourth inclined wall (112) on each side facing the corresponding first blocking part (131), and the two fourth inclined walls (112) are obtuse angles (A4) with the fourth angle on the side of the positive electrode (110) near the center region of the positive electrode (110).

5. The electrode assembly according to claim 1, characterized in that, Multiple electrode units (100) are stacked along a third direction perpendicular to the large surface of the electrode unit (100), and a diaphragm (130) is provided between adjacent electrode units (100), and the diaphragm (130) between adjacent electrode units (100) is connected to the diaphragm (130) in the multiple electrode units (100).

6. The electrode assembly according to claim 5, characterized in that, Along the first direction, the first protrusion (122) is formed on the two opposite edge portions of the body portion (121); in the second direction perpendicular to the first direction, the two opposite ends of the diaphragm (130) between adjacent electrode units (100) are respectively formed with second blocking portions (132), the second blocking portions (132) being located between the diaphragm (130) and the negative electrode (120); the two opposite second blocking portions (132) have opposing fifth inclined walls (1320), and the fifth inclined walls (1320) of the two second blocking portions (132) are obtuse angles (A5) with the fifth included angle (A5) of the diaphragm (130) on the side near the center region of the diaphragm (130); In the second direction, the negative electrode (120) has a sixth inclined wall (124) on each side facing the corresponding fifth inclined wall (1320), and the two sixth inclined walls (124) have an obtuse angle (A6) with the sixth angle on the side of the negative electrode (120) near the center region of the negative electrode (120).

7. The electrode assembly according to claim 5, characterized in that, The diaphragm (130) includes a first sub-diaphragm (133) and a second sub-diaphragm (134); in two adjacent electrode units (100), one is provided with the first sub-diaphragm (133) and the other is provided with the second sub-diaphragm (134); or, one side of the negative electrode (120) is the first sub-diaphragm (133) and the opposite side is the second sub-diaphragm (134).

8. The electrode assembly according to claim 1, characterized in that, The negative electrode (120) in the plurality of electrode units (100) is a continuous negative electrode connected together; or, the positive electrode (110) in the plurality of electrode units (100) is a continuous positive electrode connected together.

9. The electrode assembly according to claim 1, characterized in that, The negative electrode (120) further includes a second protrusion (123), which is formed on at least a portion of the edge of the body portion (121) along a first direction. The second protrusion (123) protrudes toward the side opposite to the positive electrode (110).

10. The electrode assembly according to claim 9, characterized in that, The first protrusion (122) and the second protrusion (123) are symmetrically arranged on the body part (121).

11. The electrode assembly according to claim 9, characterized in that, Along the first direction, the two opposite edge portions of the body portion (121) are respectively formed with second protrusions (123), and the two opposite second protrusions (123) have opposing seventh inclined walls (1230). The seventh inclined walls (1230) of the two second protrusions (123) are obtuse angles (A7) with the seventh angle of the body portion (121) on the side near the center region of the body portion (121). In the first direction, the positive electrode (110) and the second protrusion (123) are respectively provided with eighth inclined walls (113) facing the corresponding seventh inclined wall (1230) on their opposite sides. The two eighth inclined walls (113) are obtuse angles (A8) with the eighth angle on the side of the positive electrode (110) near the center region of the positive electrode (110).

12. The electrode assembly according to claim 9, characterized in that, The body portion (121) includes a positive electrode body and a positive electrode coating on the surface of the positive electrode body, wherein the first protrusion (122) is made of the same material as the positive electrode coating, and / or the second protrusion (123) is made of the same material as the positive electrode coating.

13. The electrode assembly according to claim 9, characterized in that, The two electrode units (100) located at both ends of the electrode assembly, in one electrode unit (100), the negative electrode (120) near the periphery of the electrode assembly does not have the first protrusion (122) provided on its surface, and in the other electrode unit (100), the negative electrode (120) near the periphery of the electrode assembly does not have the second protrusion (123) provided on its surface.

14. An energy storage device, characterized in that, include: A housing, the housing including a receiving cavity with an opening; The electrode assembly according to any one of claims 1 to 13 is housed within the receiving cavity; A top cover that seals the opening of the housing.

15. An electrical appliance, characterized in that, The electrical equipment includes the energy storage device as described in claim 14, and the energy storage device supplies power to the electrical equipment.

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