Energy storage device and electrical equipment

Abstract

The present application provides an energy storage device and an electrical equipment. The energy storage device includes an electrode assembly and a current collector plate. The current collector plate includes a plate body portion and an extension portion. The plate body portion is electrically connected to the electrode assembly. The plate body portion is provided with a through hole, and the through hole penetrates the plate body portion along the thickness direction of the plate body portion. The through hole is located at the center of the plate body portion. The extension portion is fixedly connected to the plate body portion and includes an intermediate extension section spaced from and opposite to the plate body portion. The intermediate extension section includes a first surface facing the plate body portion and a side surface connected to the first surface. At least one flow guiding groove is provided on the intermediate extension section. The opening of the flow guiding groove is located on the first surface, and the flow guiding groove penetrates the side surface. The energy storage device prepared by using the current collector plate of the present application can perform secondary distribution of the electrolyte during the use of the energy storage device, and solves the problem of uneven distribution of the electrolyte in the energy storage device, which affects the performance of the energy storage device.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage devices, and in particular to an energy storage device and an electrical equipment. Background Art

[0002] When a secondary battery or other energy storage device is charged and discharged cyclically or stored for a long time, the electrolyte in the energy storage device will gradually decompose and generate gas, resulting in uneven distribution of the electrolyte in the energy storage device, which will affect the performance of the energy storage device. For example, the problem of lithium plating occurs due to uneven distribution of the electrolyte in the energy storage device. Summary of the Invention

[0003] The purpose of the present application is to provide an energy storage device and an electrical equipment. During use, the energy storage device can redistribute the electrolyte, solving the problem that the uneven distribution of the electrolyte in the energy storage device affects the performance of the energy storage device.

[0004] An energy storage device includes an electrode assembly and a current collector plate. The current collector plate includes a plate body portion and an extension portion. The plate body portion is electrically connected to the electrode assembly. The plate body portion is provided with a through hole that penetrates the plate body portion along the thickness direction of the plate body portion. The through hole is located at the center of the plate body portion.

[0005] The extension portion is fixedly connected to the plate body portion and includes an intermediate extension section that is spaced apart from and opposite to the plate body portion. The intermediate extension section includes a first surface facing the plate body portion and a side surface connected to the first surface. The intermediate extension section is provided with at least one flow guiding groove. The opening of the flow guiding groove is located on the first surface, and the flow guiding groove penetrates the side surface.

[0006] During actual use of the energy storage device, such as during transportation, due to vibration, the electrolyte in the energy storage device will impact in the direction from the electrode assembly towards the current collector plate. An embodiment of the present application provides an energy storage device. By providing an intermediate extension section opposite to the plate body portion on the current collector plate and providing a flow guiding groove on the first surface of the intermediate extension section facing the plate body portion, the electrolyte in the energy storage device can be made to impact on the first surface of the intermediate extension section facing the plate body portion through the through hole of the plate body portion. This part of the electrolyte can flow under the guidance of the flow guiding groove and then fall back to the plate body portion, so as to realize the secondary distribution of the falling electrolyte by the plate body portion, thereby facilitating the solution of the problem of uneven distribution of the electrolyte in the energy storage device, and further facilitating the guarantee of the performance of the energy storage device and avoiding the problem of lithium plating in the energy storage device.

[0007] In a possible implementation manner, at least part of the first surface is disposed opposite to the through hole, which is conducive to the electrolyte passing through the through hole and impacting on the first surface and flowing along the first surface to the flow guiding groove, thereby facilitating the guiding of the electrolyte.

[0008] In a possible implementation, at least a part of the diversion groove is disposed opposite to the through hole in the axial direction of the current collecting plate, which is conducive to the electrolyte passing through the through hole directly impacting into the diversion groove, thereby facilitating the diversion of the electrolyte by the diversion groove.

[0009] In a possible implementation, the side surface includes a first surface and a second surface, and the first surface and the second surface are disposed opposite to each other in the width direction of the middle extension section.

[0010] A plurality of diversion grooves are provided in the middle extension section. The plurality of diversion grooves include at least one first groove and at least one second groove. The first groove and the second groove are arranged at intervals. The first groove penetrates the first surface, and the second groove penetrates the second surface. By providing the first groove and the second groove, it is possible to guide the electrolyte to flow from the middle of the middle extension section to the opposite sides in the width direction, improving the efficiency of guiding the electrolyte flow and evenly dispersing the electrolyte at the same time.

[0011] In a possible implementation, the included angle between the length direction of the diversion groove and the extension direction of the middle extension section is α, and α is an obtuse angle or an acute angle, which can increase the extension length of the diversion groove, thereby facilitating an increase in the flow rate of the electrolyte diverted by the diversion groove.

[0012] In a possible implementation, the middle extension section further includes a second surface, which is disposed opposite to the first surface and connected to the side surface, and the bottom wall of the diversion groove protrudes relative to the second surface.

[0013] A plurality of diversion grooves are provided in the middle extension section. The plurality of diversion grooves are arranged at intervals in the extension direction of the middle extension section. A diversion flow channel is formed between the bottom walls of two adjacent diversion grooves. By protruding the bottom wall of the diversion groove relative to the second surface, a diversion flow channel can be formed between the bottom walls of two adjacent diversion grooves, which is conducive to guiding the flow of the electrolyte.

[0014] In a possible implementation, the extension portion includes a first extension section, a middle extension section, and a second extension section. The first extension section is fixedly connected to the disk body portion, and the middle extension section is connected between the first extension section and the second extension section.

[0015] In a possible implementation, the disk body part is further provided with a plurality of first communication holes. The plurality of first communication holes all penetrate the disk body part along the thickness direction of the disk body part. The plurality of first communication holes are arranged at intervals from each other and are all arranged at intervals from the through hole. The sum of the areas of the plurality of first communication holes is S1, and the area of the through hole is S2, where S1 > S2. By providing the first communication holes and the through hole in the disk body part of the current collector disk, when the energy storage device is in transportation, the electrolyte that impacts the middle extension section and then falls back to the disk body part under the guidance of the diversion groove can pass through the first communication holes and the through hole for secondary distribution. During the secondary distribution of the electrolyte, since the total area S1 of the first communication holes is larger than the area S2 of the through hole, the flow rate of the falling-back electrolyte passing through the first communication holes is greater than the flow rate of the falling-back electrolyte passing through the through hole. As a result, the electrolyte content at the circumferential position of the electrode assembly far from the core axis is greater than the electrolyte content at the core axis at the center position of the electrode assembly, thus ensuring the electrolyte content at the circumferential position of the electrode assembly far from the core axis and further ensuring the performance of the energy storage device.

[0016] In a possible implementation, 21% ≤ S2 / S1 ≤ 52%, which can ensure that there is sufficient electrolyte content for consumption at both the core axis at the center position of the electrode assembly and the circumferential position of the electrode assembly far from the core axis.

[0017] In a possible implementation, the disk body part is further provided with a plurality of second communication holes. The plurality of second communication holes all penetrate the disk body part along the thickness direction of the disk body part. The plurality of second communication holes are arranged at intervals from each other and are arranged at intervals from both the through hole and the plurality of first communication holes. The plurality of second communication holes and the plurality of first communication holes are respectively located on both sides of the through hole. By providing the first communication holes and the second communication holes on both sides of the through hole simultaneously, the falling-back electrolyte can be distributed to the circumferential positions on both sides of the electrode assembly far from the core axis, which is beneficial to the uniform distribution of the electrolyte.

[0018] In a possible implementation, the sum of the areas of the plurality of second communication holes is S3, where S3 > S2, so that the flow rate of the falling-back electrolyte passing through the second communication holes is greater than the flow rate of the falling-back electrolyte passing through the through hole, to achieve the secondary distribution of the electrolyte. At the same time, it is ensured that during the secondary distribution of the electrolyte, the flow rate of the electrolyte falling back to the circumferential position of the electrode assembly is greater than the flow rate of the electrolyte falling back to the center position of the electrode assembly, thus ensuring the electrolyte content at the circumferential position of the electrode assembly far from the core axis and further ensuring the performance of the energy storage device.

[0019] In a possible implementation, 21% ≤ S2 / S3 ≤ 52%, which can ensure that there is sufficient electrolyte content for consumption at both the core axis at the center position of the electrode assembly and the circumferential position of the electrode assembly far from the core axis.

[0020] In a possible implementation, S1 = S3, so that the recirculated electrolyte can be evenly distributed to the circumferential positions on both sides of the electrode assembly away from the mandrel, avoiding the phenomenon of lithium plating.

[0021] In a possible implementation, the electrode assembly has a mandrel, and the mandrel of the electrode assembly is disposed opposite to the through hole.

[0022] An embodiment of the present application further provides an electrical device, which includes the energy storage device as described above, and the energy storage device supplies power to the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 It is an application scenario diagram of the energy storage device provided by the embodiment of the present application applied to an energy storage system;

[0025] Figure 2 It is a schematic structural diagram of the energy storage device provided by the first embodiment of the present application;

[0026] Figure 3 For Figure 2 It is an exploded structural diagram of the end cap assembly in the shown energy storage device;

[0027] Figure 4 For Figure 3 It is a schematic structural diagram of the first insulating component in the shown end cap assembly from another perspective;

[0028] Figure 5 For Figure 3 It is a schematic structural diagram of the current collector plate in the unfolded state in the shown end cap assembly;

[0029] Figure 6 For Figure 5 It is a schematic structural diagram of the middle extension section of the shown current collector plate;

[0030] Figure 7 For Figure 5 It is a schematic structural diagram of the shown current collector plate in the folded state;

[0031] Figure 8 For Figure 3 It is a partial cross-sectional structural diagram of the shown end cap assembly;

[0032] Figure 9 It is a schematic structural diagram of the current collector plate in the unfolded state in the energy storage device according to the second embodiment of the present application;

[0033] Figure 10 This is a schematic structural diagram of the current collector plate in the folded state in the energy storage device according to the third embodiment of the present application.

[0034] Reference numerals: 1, power conversion device; 2, user load; 1000, energy storage device; 100, housing; 200, end cover assembly; 10, end cover; 12, fixing hole; 14, pressure relief hole; 15, mounting groove; 20, explosion-proof valve; 21, protection member; 30, pole column; 31, column body part; 32, protruding part; 33, carrier seat part; 40, first insulating member; 41, insulating body; 42, convex block; 43, embedding groove; 44, through hole; 50, voltage-conducting block; 53, connection hole; 60, second insulating member; 63, mounting hole; 64, through hole; 80, current collector plate; 81, plate body part; 811, through hole; 812, first communication hole; 813, welding groove; 814, second communication hole; 82, extension part; 821, first extension section; 822, intermediate extension section; 823, second extension section; 801, first surface; 802, second surface; 803, side surface; 803a, first face; 803b, second face; 83, flow guiding groove; 831, first groove; 831a, first side wall; 831b, second side wall; 831c, third side wall; 832, second groove; 832a, fourth side wall; 832b, fifth side wall; 832c, sixth side wall; 833, first notch; 834, second notch; 84, fixing groove; 86, flow guiding channel; 90, sealing member. Detailed implementation manners

[0035] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present application.

[0036] Since the energy required by people has strong temporality and spatiality, in order to rationally utilize energy and improve the energy utilization rate, it is necessary to store one form of energy in the same or converted into another form of energy through a medium or device, and then release it in a specific energy form based on future application needs. As is well known, to achieve the great goal of carbon neutrality, the current main way to generate green electric energy is to develop green energy such as photovoltaic and wind power to replace fossil energy.

[0037] At present, the generation of green electric energy generally relies on photovoltaic, wind power, water potential, etc. However, wind energy and solar energy generally have problems such as strong intermittency and large volatility, which will cause the power grid to be unstable. There is not enough electricity during peak electricity consumption, and too much electricity during low electricity consumption. The unstable voltage will also damage the electricity. Therefore, the problems of "abandoning wind and light" may be caused due to insufficient electricity demand or insufficient grid acceptance capacity. To solve these problems, energy storage is required. That is, the electric energy is converted into other forms of energy through physical or chemical means and stored, and the energy is converted back into electric energy and released when needed. Simply put, energy storage is similar to a large "portable power bank". When photovoltaic and wind energy are sufficient, the electric energy is stored, and the stored electricity is released when needed.

[0038] Taking electrochemical energy storage as an example, an embodiment of the present application provides an energy storage device. A set of chemical batteries are provided inside the energy storage device. The chemical elements inside the chemical batteries are mainly used as energy storage media. The charge and discharge process is accompanied by chemical reactions or changes of the energy storage media. Simply put, the electric energy generated by wind energy and solar energy is stored in the chemical batteries, and the stored electricity is released when the external electricity usage reaches the peak, or transferred to places with a shortage of electricity for further use.

[0039] At present, the application scenarios of energy storage (i.e., energy storage) are relatively extensive, including power generation side energy storage, grid side energy storage, renewable energy grid connection energy storage, and user side energy storage, etc. The types of corresponding energy storage devices include:

[0040] (1) A large energy storage container applied to the grid side energy storage scenario, which can be used as a high-quality active and reactive power regulation power source in the grid, realize the load matching of electric energy in time and space, enhance the consumption capacity of renewable energy, and is of great significance in grid system standby, alleviating the power supply pressure during peak loads, and peak shaving and frequency modulation;

[0041] (2) Small and medium-sized energy storage cabinets applied to the industrial and commercial energy storage scenarios (banks, shopping malls, etc.) on the user side and household small energy storage boxes applied to the household energy storage scenarios on the user side. The main operation mode is "peak shaving and valley filling". Since there is a large price difference in electricity bills at peak and valley positions according to electricity consumption demand, after users have energy storage devices, in order to reduce costs, they usually charge the energy storage cabinets / boxes during the low electricity price period; during the peak electricity price period, the electricity in the energy storage devices is released for use to achieve the purpose of saving electricity bills. In addition, in remote areas and areas with high incidences of natural disasters such as earthquakes and hurricanes, the existence of household energy storage devices is equivalent to users providing backup power for themselves and the power grid, eliminating the inconvenience caused by frequent power outages due to disasters or other reasons.

[0042] Please refer to Figure 1 , Figure 1 which is the application scenario diagram of the energy storage device 1000 provided by the embodiment of the present application applied to the energy storage system.

[0043] As shown Figure 1 in the figure, the embodiment of the present application takes the household energy storage scenario in user-side energy storage as an example for illustration. However, it should be understood that the energy storage system provided by the present application is not limited to the household energy storage scenario. In this embodiment, the energy storage system can be a household energy storage system. The energy storage system includes an electric energy conversion device 1, a user load 2, and an energy storage device 1000. Among them, the energy storage device 1000 is a small energy storage box and can be installed on an outdoor wall in a wall-mounted manner. Exemplarily, the electric energy conversion device 1 can be a photovoltaic panel. The electric energy conversion device 1 can convert solar energy into electric energy during the low electricity price period. The energy storage device 1000 is used to store the electric energy and supply it to user loads 2 such as street lights and household appliances for use during the peak electricity price period, or to supply power when the power grid is powered off / out of power. In this embodiment, the energy storage device 1000 can be, but is not limited to, a single battery, a battery module, a battery pack, and a battery system, etc. Exemplarily, when the energy storage device 1000 is a single battery, it can be a cylindrical battery or a square battery.

[0044] Please refer to Figure 2 , Figure 2 which is a schematic structural diagram of the energy storage device 1000 provided by the first embodiment of the present application.

[0045] In this embodiment, the energy storage device 1000 takes a cylindrical lithium-ion battery as an example. Among them, the length and width of the energy storage device 1000 are approximately equal. The energy storage device 1000 includes a housing 100, an electrode assembly ( Figure 2 not shown), and two end cap assemblies 200. The housing 100 is a cylindrical housing. The housing 100 has an opening, and the electrode assembly is installed inside the housing 100. Along the Z-axis direction, the two end cap assemblies 200 are respectively installed on opposite sides of the housing 100, close the opening of the housing 100, and are both electrically connected to the electrode assembly.

[0046] Specifically, the electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate and the negative electrode plate are arranged at intervals and opposite to each other, and the separator is located between the positive electrode plate and the negative electrode plate. Exemplarily, after the positive electrode plate, the separator, and the negative electrode plate are stacked in sequence, they are wound to form an electrode assembly. The middle part of the wound electrode assembly forms a mandrel, the mandrel is hollow, and can accommodate electrolyte. Among them, the tab of the positive electrode plate is the positive electrode tab, and the tab of the negative electrode plate is the negative electrode tab.

[0047] Among the two end cap assemblies 200, one end cap assembly 200 is the end cap assembly on the negative electrode side, and the other end cap assembly 200 is the end cap assembly on the positive electrode side. The end cap assembly 200 on the negative electrode side is electrically connected to the negative electrode tab in the electrode assembly, and the end cap assembly 200 on the positive electrode side is electrically connected to the positive electrode tab in the electrode assembly, thereby realizing the electrical connection between the two end cap assemblies 200 and the electrode assembly.

[0048] In the embodiment of the present application, the electrode assembly fixedly connected to the two end cap assemblies 200 is placed in the housing 100, and the end caps of the two end cap assemblies 200 are respectively fixedly connected to the housing 100, and then the electrolyte is injected from the end cap assembly 200 on the positive electrode side to assemble and form the energy storage device 1000. The electrode assembly is immersed in the electrolyte, and an electrochemical reaction can occur between the electrode assembly and the electrolyte, and chemical energy is converted into electrical energy, so that the energy storage device 1000 can output electrical energy to the outside.

[0049] In the embodiment of the present application, the end cap assembly 200 is described by taking the end cap assembly on the negative electrode side as an example. Figure 3 , Figure 3 for Figure 2 A schematic diagram of the exploded structure of the end cover assembly 200 in the energy storage device 1000 is shown.

[0050] The end cap assembly 200 includes an end cap 10, an explosion-proof valve 20, a protective member 21, a pole 30, a first insulating member 40, a conductive voltage block 50, a second insulating member 60 and a current collecting plate 80. The explosion-proof valve 20 is installed on the end cap 10 to prevent the energy storage device 1000 from exploding during use. The protective member 21 is installed on the end cap 10 to protect the explosion-proof valve 20 and prevent the external environment and external forces from damaging the explosion-proof valve 20. The pole 30 is penetrated by the end cap 10 and protrudes relative to the end cap 10 along the positive direction of the Z axis. The first insulating member 40 is installed on the side of the end cap 10 away from the positive direction of the Z axis, and is installed between the end cap 10 and the pole 30 to insulate and isolate the end cap 10 and the pole 30. The conductive voltage block 50 is installed on the side of the first insulating member 40 away from the end cap 10, and is sleeved on the peripheral side of the pole 30, and is used to compress and fix the pole 30. The second insulating component 60 is installed on the side of the end cover 10 facing the negative direction of the Z axis and installed between the end cover 10 and the current collecting plate 80 to insulate and isolate the end cover 10 and the current collecting plate 80. The current collecting plate 80 is installed on the side of the second insulating component 60 away from the end cover 10 and is electrically connected to the pole 30.

[0051] When assembling the energy storage device 1000 , the current collecting plate 80 in the end cap assembly 200 is welded and fixed to the negative electrode tab in the electrode assembly to achieve electrical connection between the end cap assembly 200 and the electrode assembly.

[0052] Continue to see Figure 3, the end cap 10 is provided with a fixing hole 12, a pressure relief hole 14 and a mounting groove 15. Both the fixing hole 12 and the pressure relief hole 14 penetrate the end cap 10 along the thickness direction of the end cap 10, that is, along the Z-axis direction. Among them, the fixing hole 12 is located at the center of the end cap 10. In this embodiment, the fixing hole 12 is a circular hole. The pressure relief hole 14 is arranged at an interval from the fixing hole 12. The opening of the mounting groove 15 faces the positive direction of the Z-axis, and is recessed from the surface of the end cap 10 facing the positive direction of the Z-axis to the surface facing the negative direction of the Z-axis. The mounting groove 15 is arranged around the fixing hole 12 and communicates with the fixing hole 12.

[0053] The explosion-proof valve 20 is installed on the positive end cap 10 and covers the pressure relief hole 14 to block the pressure relief hole 14. Among them, the explosion-proof valve 20 covers the opening of the pressure relief hole 14 facing the current collector plate 80. The protection member 21 is installed on the positive end cap 10 and covers the opening of the pressure relief hole 14 facing away from the current collector plate 80 to protect the explosion-proof valve 20 and prevent the external environment and external forces from damaging the explosion-proof valve 20.

[0054] The pole column 30 includes a column body part 31, a protruding part 32 and a carrier part 33. In this embodiment, the height direction of the pole column 30 is the Z-axis direction, and the protruding part 32 and the carrier part 33 are connected to opposite ends of the column body part 31 along the height direction. In this embodiment, the column body part 31 is generally cylindrical. The protruding part 32 protrudes from the circumferential side surface of the column body part 31. The carrier part 33 is generally in the shape of a circular plate and protrudes from the circumferential side surface of the column body part 31.

[0055] Referring to Figure 4 , Figure 4 is Figure 3 a schematic structural view of the first insulating member 40 in another perspective in the end cap assembly 200 shown. The first insulating member 40 includes an insulating body 41 and a convex block 42, and the convex block 42 protrudes from the surface of the insulating body 41. Specifically, the convex block 42 protrudes from the surface of the insulating body 41 facing the end cap 10. The shape and size of the convex block 42 are substantially the same as those of the mounting groove 15. In this embodiment, the insulating body 41 and the convex block 42 are integrally formed and are both made of insulating materials.

[0056] In addition, the first insulating member 40 is provided with an embedding groove 43 and a through hole 44. Among them, the thickness direction of the first insulating member 40 is the Z-axis direction. The opening of the embedding groove 43 is located on the surface of the insulating body 41 facing away from the end cap 10. The embedding groove 43 is recessed from the surface of the insulating body 41 facing away from the end cap 10 to the surface facing the end cap 10. The opening of the through hole 44 is arranged on the bottom wall of the embedding groove 43, and along the thickness direction of the first insulating member 40, the through hole 44 penetrates the insulating body 41 and the convex block 42.

[0057] Continuing to refer to Figure 3, the shape and size of the conductive voltage block 50 are substantially the same as those of the embedding groove 43. The conductive voltage block 50 is provided with a connection hole 53, and the connection hole 53 penetrates through the conductive voltage block 50 along the thickness direction of the conductive voltage block 50.

[0058] The second insulating member 60 is provided with a mounting hole 63 and a through hole 64. Both the mounting hole 63 and the through hole 64 penetrate through the second insulating member 60 along the thickness direction of the second insulating member 60. Among them, the second insulating member 60 is generally circular, the mounting hole 63 is located at the center of the second insulating member 60, and the through hole 64 is arranged at an interval from the mounting hole 63.

[0059] Refer to Figure 5 , Figure 5 is Figure 3 the schematic structural diagram of the current collector plate 80 in the unfolded state in the end cover assembly 200 shown in Figure 5 The dashed lines in

[0060] only serve to indicate the areas of the various parts in the extension part 82 and do not represent the actual structure.

[0061] The current collector plate 80 includes a plate body part 81 and an extension part 82, and the extension part 82 is fixedly connected to the plate body part 81. In this embodiment, the plate body part 81 is generally disc-shaped, the extension part 82 is generally strip-shaped, and the extension part 82 and the plate body part 81 are welded.

[0062] The plate body part 81 is provided with a through hole 811, a plurality of first communication holes 812 and a welding groove 813. Both the through hole 811 and the plurality of first communication holes 812 penetrate through the plate body part 81 along the thickness direction of the plate body part 81. Specifically, the through hole 811 is located at the center of the plate body part 81. The plurality of first communication holes 812 are arranged at intervals from each other, are located on one side of the through hole 811, and are all arranged at intervals from the through hole 811. Among them, the area of the plurality of first communication holes 812 is S1, the area of the through hole 811 is S2, and S1 > S2. In some embodiments, 21% ≤ S2 / S1 ≤ 52%. In this application, the "area" of the hole refers to the cross-sectional area of the hole. For example, the area of the through hole 811 refers to the cross-sectional area of the through hole 811.

[0063] The extension part 82 is strip-shaped. The extension part 82 includes a first extension segment 821, an intermediate extension segment 822, and a second extension segment 823. The first extension segment 821 is fixedly connected to the disk body part 81 to realize the fixed connection between the extension part 82 and the disk body part 81. The intermediate extension segment 822 is connected between the first extension segment 821 and the second extension segment 823. In this embodiment, the first extension segment 821, the intermediate extension segment 822, and the second extension segment 823 are integrally formed.

[0064] Referring to Figure 6 , Figure 6 is Figure 5 a schematic structural diagram of the intermediate extension segment 822 of the current collector plate 80 shown in the figure. Wherein, the intermediate extension segment 822 includes a first surface 801, a second surface 802, and a side surface 803. Specifically, the first surface 801 and the second surface 802 are arranged opposite to each other along the thickness direction of the intermediate extension segment 822, that is, opposite to each other along the Z-axis direction. The side surface 803 is connected between the first surface 801 and the second surface 802. Specifically, the side surface 803 includes a first surface 803a and a second surface 803b, and the first surface 803a and the second surface 803b are arranged opposite to each other along the width direction of the intermediate extension segment 822, and are both connected between the first surface 801 and the second surface 802.

[0065] The current collector plate 80 is also provided with a diversion groove 83. The opening of the diversion groove 83 is arranged on the first surface 801 of the intermediate extension segment 822. The diversion groove 83 is recessed from the first surface 801 towards the second surface 802, and penetrates the side surface 803, and can be used to guide the flow of the electrolyte. Exemplarily, there may be multiple diversion grooves 83, and the multiple diversion grooves 83 are arranged at intervals along the extension direction of the intermediate extension segment 822. In this embodiment, the bottom wall of the diversion groove 83 protrudes relative to the second surface 802, and a diversion channel 86 is formed between the bottom walls of two adjacent diversion grooves 83, and the diversion channel 86 is used to guide the flow of the electrolyte. Exemplarily, the diversion groove 83 can be formed by a stamping process.

[0066] The included angle between the length direction of the diversion groove 83 and the extension direction of the intermediate extension segment 822 is α, and α is an obtuse angle or an acute angle, which can increase the extension length of the diversion groove 83, thereby facilitating an increase in the flow rate of the electrolyte diverted by the diversion groove 83. Exemplarily, as Figure 4 shown, α is an obtuse angle, and in other embodiments, α can also be an acute angle.

[0067] In this embodiment, the plurality of diversion grooves 83 include at least one first groove 831 and at least one second groove 832, and the plurality of first grooves 831 and the plurality of second grooves 832 are arranged at intervals. The plurality of first grooves 831 and the plurality of second grooves 832 are both arranged at intervals along the extending direction of the middle extension section 822. In this embodiment, the number of both the first groove 831 and the second groove 832 is three. In other embodiments, the number of the first groove 831 and the second groove 832 may be one, two, four, etc., and the embodiments of the present application do not limit the number of the first groove 831 and the second groove 832. In addition, the number of the first groove 831 and the second groove 832 may be equal or unequal.

[0068] Among them, the first groove 831 penetrates the first surface 803a. The first groove 831 includes a first notch 833 located on the first surface 803a. Specifically, the groove sidewall of the first groove 831 includes a first sidewall 831a, a second sidewall 831b, and a third sidewall 831c. The first sidewall 831a and the second sidewall 831b are oppositely arranged along the width direction of the first groove 831. The third sidewall 831c is connected between the first sidewall 831a and the second sidewall 831b and is oppositely arranged with the first notch 833. The electrolyte located in the first groove 831 can flow toward the first notch 833 along the length direction of the first groove 831 (i.e., along the direction of the third sidewall 831c toward the first notch 833) and flow out from the first notch 833.

[0069] In this embodiment, the included angle between the length direction of the first groove 831 and the extending direction of the middle extension section 822 is α1, and α1 is an obtuse angle, which can increase the extending length of the first groove 831, thereby facilitating an increase in the flow rate of the electrolyte diverted by the first groove 831.

[0070] The second groove 832 penetrates the second surface 803b. The second groove 832 includes a second notch 834 located on the second surface 803b. Specifically, the groove sidewall of the second groove 832 includes a fourth sidewall 832a, a fifth sidewall 832b, and a sixth sidewall 832c. The fourth sidewall 832a and the fifth sidewall 832b are oppositely arranged along the width direction of the second groove 832. The sixth sidewall 832c is connected between the fourth sidewall 832a and the fifth sidewall 832b and is oppositely arranged with the second notch 834. The electrolyte located in the second groove 832 can flow toward the second notch 834 along the length direction of the second groove 832 (i.e., from the fifth sidewall 832b toward the second notch 834) and flow out from the second notch 834.

[0071] In this embodiment, the included angle α2 between the length direction of the second groove 832 and the extending direction of the middle extending section 822 is an obtuse angle, which can increase the extending length of the second groove 832, thereby facilitating an increase in the flow rate of the electrolyte guided by the second groove 832. In this embodiment, the second groove 832 is symmetrically arranged with the first groove 831. By providing the first groove 831 and the second groove 832 in the embodiment of the present application, it is possible to guide the electrolyte to flow from the middle of the middle extending section 822 to the opposite sides in the width direction, improving the efficiency of guiding the flow of the electrolyte, and at the same time being able to evenly disperse the electrolyte.

[0072] Continue to refer to Figure 5 , the current collector plate 80 is further provided with a fixing groove 84. The fixing groove 84 is provided in the second extending section 823 and penetrates the second extending section 823 along the thickness direction of the second extending section 823.

[0073] Combined with referring to Figure 5 and Figure 7 , Figure 7 is Figure 5 the schematic structural diagram of the current collector plate 80 in the folded state shown in

[0074] The current collector plate 80 has an unfolded state and a folded state. When the current collector plate 80 is in the unfolded state, the surface of the plate body portion 81 is substantially parallel to the surface of the extending portion 82, and the first extending section 821, the middle extending section 822, and the second extending section 823 in the extending portion 82 are substantially in the same plane.

[0075] When the current collector plate 80 is in the folded state, the portion of the first extending section 821 facing the middle extending section 822 is bent, the portion of the second extending section 823 facing the middle extending section 822 is bent, and the middle extending section 822 is spaced apart from and opposite to the plate body portion 81. Among them, the first surface 801 of the middle extending section 822 faces the plate body portion 81, that is, the opening of the diversion groove 83 faces the plate body portion 81, and the second surface 802 faces away from the plate body portion 81. In this embodiment, at least part of the first surface 801 is disposed opposite to the through hole 811, which is beneficial for the electrolyte passing through the through hole 811 to impact on the first surface 801 and flow along the first surface 801 to the diversion groove 83, thereby facilitating the diversion of the electrolyte. At least a part of the diversion groove 83 is axially opposite to the through hole 811 along the current collector plate 80, which is beneficial for the electrolyte passing through the through hole 811 to directly impact into the diversion groove 83, thereby facilitating the use of the diversion groove 83 to divert the electrolyte.

[0076] Continue to refer to Figure 3, in this embodiment, the end cap assembly 200 further includes a seal 90. Specifically, the seal 90 is sleeved on the circumferential side surface of the pole column 30 and clamped between the end cap 10 and the pole column 30, which can not only insulate the end cap and the pole column, but also improve the installation tightness between the end cap 10 and the pole column 30, thereby improving the tightness of the assembled end cap assembly 200. In this embodiment, the seal 90 is an O-ring.

[0077] Referring to Figure 3 and Figure 8 , Figure 8 is Figure 3 a partial cross-sectional structural schematic diagram of the end cap assembly 200 shown.

[0078] In the assembled end cap assembly 200, the explosion-proof valve 20 is installed on the end cap 10 and covers the pressure relief hole 14. The convex block 42 of the first insulating component 40 is installed in the installation groove 15 of the end cap 10, and the voltage-conducting block 50 is installed in the embedding groove 43 of the first insulating component 40, so as to realize the stacked installation of the first insulating component 40 and the voltage-conducting block 50 on one side of the end cap 10 along the thickness direction. At this time, the connection hole 53 of the voltage-conducting block 50, the through hole 44 of the first insulating component 40 and the fixing hole 12 of the end cap 10 are communicated. The second insulating component 60 is installed on the side of the end cap 10 facing away from the first insulating component 40. The current collector plate 80 is installed on the side of the second insulating component 60 facing away from the end cap 10. At this time, the installation hole 63 of the second insulating component 60, the fixing hole 12 of the end cap 10 and the fixing groove 84 of the second extension section 823 in the current collector plate 80 are communicated. The through hole 64 of the second insulating component 60 is communicated with the pressure relief hole 14 of the end cap 10.

[0079] The pole column 30 sequentially passes through the connection hole 53 of the voltage-conducting block 50, the through hole 44 of the first insulating component 40, the fixing hole 12 of the end cap 10, the installation hole 63 of the second insulating component 60 and the fixing groove 84 of the current collector plate 80. Among them, the protruding part 32 of the pole column 30 abuts against and is fixed to the inner wall of the connection hole 53 and protrudes relative to the connection hole 53. The carrier part 33 abuts against the surface of the second extension section 823 in the current collector plate 80 facing away from the end cap 10. The seal 90 is sleeved on the circumferential side surface of the column body part 31 of the pole column 30, so as to realize that the seal 90 is sleeved on the circumferential side surface of the pole column 30. The seal 90 is installed by abutting between the convex block 42 of the first insulating component 40 and the carrier part 33 of the pole column 30, so as to realize the installation of the seal 90 between the first insulating component 40 and the carrier part 33.

[0080] At least one of the plurality of first communication holes 812 of the current collector plate 80 is disposed opposite to the through hole 64 of the second insulating member 60, so that the gas generated by the electrode assembly can sequentially pass through the first communication hole 812 and the through hole 64 and quickly converge to the pressure relief hole 14, which is beneficial to the opening of the explosion-proof valve covering the pressure relief hole 14. The bottom wall of the welding groove 813 of the disk body portion 81 in the current collector plate 80 is welded to the electrode assembly. At this time, the through hole 811 of the current collector plate 80 is disposed opposite to the mandrel of the electrode assembly.

[0081] It can be understood that in the energy storage device 1000, a large amount of electrolyte fills the mandrel in the middle position of the electrode assembly. The wettability of the middle positions of the positive and negative plates in the electrode assembly near the mandrel is the highest in the electrolyte, while the wettability of the peripheral positions far from the middle position is lower in the electrolyte. During the use of the energy storage device 1000, such as during cyclic charge and discharge or long-term storage, the electrolyte in the energy storage device 1000 will gradually be consumed, making the problem of uneven electrolyte distribution in the energy storage device 1000 more obvious after long-term use. To ensure the content of the electrolyte at the peripheral position of the electrode assembly far from the mandrel, it is necessary to re-distribute the electrolyte in the energy storage device 1000 so that more electrolyte is distributed to the peripheral position of the electrode assembly far from the mandrel, that is, more electrolyte is distributed to the positions where the electrolyte is scarce in the electrode assembly.

[0082] During the actual use of the energy storage device 1000, such as during transportation, due to vibration, the electrolyte in the energy storage device 1000 will impact from the mandrel of the electrode assembly towards the current collector plate 80. In the embodiment of the present application, by providing an intermediate extension section 822 on the current collector plate 80 and providing a diversion groove 83 on the first surface 801 of the intermediate extension section 822, part of the electrolyte will impact on the first surface 801 of the intermediate extension section 822 facing the disk body portion 81. This part of the electrolyte can flow under the guidance of the diversion groove 83 and fall back to the first communication hole 812 and the through hole 811 provided on the disk body portion 81 for re-distribution of the electrolyte. Specifically, part of this part of the electrolyte can impact on the first groove 831 in the diversion groove 83, flow from the length direction of the first groove 831 to the first notch 833, flow out from the first notch 833 and fall onto the disk body portion 81, and then fall back into the interior of the energy storage device 1000 through the first communication hole 812 and the through hole 811 to complete the re-distribution of the electrolyte. Part of this part of the electrolyte can impact on the second groove 832 in the diversion groove 83, flow from the fifth side wall 832b of the second groove 832 to the second notch 834, flow out from the second notch 834 and fall onto the first communication hole 812 and the through hole 811 of the disk body portion 81 to complete the re-distribution of the electrolyte.

[0083] Meanwhile, a part of the electrolyte can impact the second surface 802 of the middle extension section 822 facing away from the disk body portion 81. This part of the electrolyte can flow along the flow guiding channels 86 formed between the bottom wall of the plurality of flow guiding grooves 83 protruding relative to the second surface 802, and then fall back into the first communication hole 812 and the through hole 811 for secondary distribution of the electrolyte. In this embodiment, the concave portion formed by the flow guiding grooves 83 relative to the first surface 801 and the protruding portion of the bottom wall relative to the second surface 802 are used to guide the flow of the electrolyte, ensuring the content of the electrolyte at the circumferential position of the electrode assembly far from the core axis, and further ensuring the performance of the energy storage device 1000 and avoiding the problem of lithium plating in the energy storage device.

[0084] In addition, in this embodiment, by providing the first communication hole 812 and the through hole 811 in the disk body portion 81 of the current collector disk 80, the electrolyte that impacts the middle extension section 822 and falls back to the disk body portion 81 under the guidance of the flow guiding grooves during the transportation of the energy storage device 1000 can pass through the first communication hole 812 and the through hole 811 for secondary distribution. During the secondary distribution of the electrolyte, since the total area S1 of the first communication hole 812 is larger than the area S2 of the through hole 811, the flow rate of the falling-back electrolyte passing through the first communication hole 812 is greater than the flow rate of the falling-back electrolyte passing through the through hole 811. As a result, the content of the electrolyte falling back to the circumferential position of the electrode assembly far from the core axis is greater than the content of the electrolyte falling back to the core axis at the central position of the electrode assembly, thus ensuring the content of the electrolyte at the circumferential position of the electrode assembly far from the core axis, and further ensuring the performance of the energy storage device 1000 and avoiding the problem of lithium plating in the energy storage device.

[0085] During the operation of the electrode assembly of the energy storage device 1000, more electrolyte is consumed at the core axis at the central position of the electrode assembly. In some embodiments, by setting 21% ≤ S2 / S1 ≤ 52%, it can ensure that there is sufficient electrolyte content for consumption both at the core axis at the central position of the electrode assembly and at the circumferential position of the electrode assembly far from the core axis.

[0086] The embodiment of the present application also provides an electrical device, which includes the energy storage device 1000 as described above, and the energy storage device 1000 supplies power to the electrical device.

[0087] Refer to Figure 9 , Figure 9 which is a schematic structural diagram of the current collector disk 80 in the unfolded state of the energy storage device 1000 according to the second embodiment of the present application.

[0088] The structure of the energy storage device 1000 in the second embodiment is the same as that of the energy storage device 1000 in the first embodiment. The difference is that the disk body portion 81 of the current collector disk 80 of the energy storage device 1000 in the second embodiment is further provided with a second communication hole 814.

[0089] Specifically, there are multiple second communication holes 814. The multiple second communication holes 814 all penetrate through the disk body portion 81 along the thickness direction of the disk body portion 81 and are arranged at intervals from each other. The multiple second communication holes 814 are arranged at intervals from the through hole 811 and the multiple first communication holes 812. The multiple second communication holes 814 and the multiple first communication holes 812 are respectively located on opposite sides of the through hole 811. Among them, the sum of the areas of the multiple second communication holes 814 is S3, and S3 > the area S2 of the through hole 811.

[0090] During the working process of the electrode assembly of the energy storage device 1000, more electrolyte needs to be consumed at the mandrel at the central position of the electrode assembly. In some embodiments, by setting 21% ≤ S2 / S3 ≤ 52%, it can be ensured that there is sufficient electrolyte content for consumption at both the mandrel at the central position of the electrode assembly and the circumferential position of the electrode assembly far from the mandrel.

[0091] During the actual use of the energy storage device 1000, such as during transportation, the electrolyte can impact towards the direction of the current collecting plate 80 through the through hole 811 of the current collecting plate 80, impact on the middle extension section 822 and fall back to the electrolyte on the disk body portion 81 under the guidance of the diversion groove 83, and can fall back and pass through the first communication hole 812, the through hole 811 and the second communication hole 814 for secondary distribution of the electrolyte. Since the sum of the areas S3 of the second communication holes 814 is also greater than the area S2 of the through hole 811, the flow rate of the falling-back electrolyte passing through the second communication holes 814 is greater than the flow rate of the falling-back electrolyte passing through the through hole 811, so as to realize the secondary distribution of the electrolyte. At the same time, it is ensured that during the secondary distribution of the electrolyte, the flow rate of the electrolyte falling back to the circumferential position of the electrode assembly far from the mandrel is greater than the flow rate of the electrolyte falling back to the central position of the electrode assembly, thereby ensuring the electrolyte content at the circumferential position of the electrode assembly far from the mandrel, and further ensuring the performance of the energy storage device 1000.

[0092] In addition, by simultaneously arranging the first communication holes 812 and the second communication holes 814 on both sides of the through hole 811, the falling-back electrolyte can be distributed to the circumferential positions on both sides of the electrode assembly far from the mandrel, which is beneficial to the uniform distribution of the electrolyte. In this embodiment, the sum of the areas S1 of the first communication holes 812 is equal to the sum of the areas S3 of the second communication holes 814, so that the falling-back electrolyte can be evenly distributed to the circumferential positions on both sides of the electrode assembly far from the mandrel, which can effectively avoid the phenomenon of lithium deposition and ensure the performance of the energy storage device 1000.

[0093] Refer to Figure 10 , Figure 10 which is a schematic structural diagram of the current collecting plate 80 in the folded state in the energy storage device 1000 according to the third embodiment of the present application.

[0094] The energy storage device 1000 of the third embodiment has the same structure as the energy storage device 1000 of the first embodiment, except that the flow guiding groove 83 of the current collecting plate 80 in the energy storage device 1000 of the third embodiment is different from the flow guiding groove 83 of the current collecting plate 80 in the energy storage device 1000 of the first embodiment.

[0095] Specifically, the bottom wall of the flow guiding groove 83 in this embodiment does not protrude relative to the second surface 802, that is, the surface of the bottom wall of the flow guiding groove 83 facing away from the opening of the flow guiding groove 83 is substantially flush with the second surface 802. At this time, the electrolyte passing through the through hole 811 of the current collecting plate 80 can impact the flow guiding groove 83 provided on the first surface 801 under the action of vibration, flow along the flow guiding groove 83 to the disk body portion 81, and then perform secondary distribution of the electrolyte through the first communication hole 812 and the through hole 811 again, ensuring that during the secondary distribution of the electrolyte, the flow rate of the electrolyte falling back to the peripheral position of the electrode assembly is greater than the flow rate of the electrolyte falling back to the central position of the electrode assembly, thereby ensuring the content of the electrolyte at the peripheral position of the electrode assembly far from the core shaft, and further ensuring the performance of the energy storage device 1000.

[0096] It can be understood that a second communication hole 814 may also be provided in the current collecting plate 80 of this embodiment, and the second communication hole 814 is the same as the second communication hole 814 provided in the second embodiment.

[0097] The foregoing disclosures are only the preferred embodiments of the present application. Of course, the scope of rights of the present application cannot be limited thereby. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present application still fall within the scope covered by the present application.

Claims

1. An energy storage device (1000), characterized in that, It includes an electrode assembly and a current collector plate (80). The current collector plate (80) includes a plate body portion (81) and an extension portion (82). The plate body portion (81) is electrically connected to the electrode assembly. The plate body portion (81) is provided with a through hole (811). The through hole (811) penetrates the plate body portion (81) along the thickness direction of the plate body portion (81). The through hole (811) is located at the center of the plate body portion (81). The extension portion (82) is fixedly connected to the plate body portion (81), and includes an intermediate extension section (822) that is spaced apart from and opposite to the plate body portion (81). The intermediate extension section (822) includes a first surface (801) facing the plate body portion (81) and a side surface (803) connected to the first surface (801). The intermediate extension section (822) is provided with at least one diversion groove (83). The opening of the diversion groove (83) is located on the first surface (801). The diversion groove (83) penetrates the side surface (803).

2. The energy storage device (1000) according to claim 1, wherein At least part of the first surface (801) is disposed opposite to the through hole (811).

3. The energy storage device (1000) according to claim 2, wherein At least a part of the diversion groove (83) is disposed opposite to the through hole (811) in the axial direction of the current collector plate (80).

4. The energy storage device (1000) according to any one of claims 1 to 3, characterized in that, The side surface (803) includes a first surface (803a) and a second surface (803b). Along the width direction of the intermediate extension section (822), the first surface (803a) and the second surface (803b) are disposed opposite to each other; The intermediate extension section (822) is provided with a plurality of the diversion grooves (83). The plurality of the diversion grooves (83) include at least one first groove (831) and at least one second groove (832). The first groove (831) and the second groove (832) are spaced apart. The first groove (831) penetrates the first surface (803a). The second groove (832) penetrates the second surface (803b).

5. The energy storage device (1000) according to any one of claims 1 to 3, characterized in that, The included angle between the length direction of the diversion groove (83) and the extension direction of the intermediate extension section (822) is α, and α is an obtuse angle or an acute angle.

6. The energy storage device (1000) according to any one of claims 1 to 3, characterized in that, The intermediate extension section (822) further includes a second surface (802). The second surface (802) is disposed opposite to the first surface (801) and is connected to the side surface (803). The bottom wall of the diversion groove (83) protrudes relative to the second surface (802); The intermediate extension section (822) is provided with a plurality of the diversion grooves (83). The plurality of the diversion grooves (83) are spaced apart along the extension direction of the intermediate extension section (822). A diversion flow channel (86) is formed between the bottom walls of two adjacent diversion grooves (83).

7. The energy storage device (1000) according to claim 1, wherein, The extension portion (82) includes a first extension section (821), the intermediate extension section (822) and a second extension section (823). The first extension section (821) is fixedly connected to the plate body portion (81). The intermediate extension section (822) is connected between the first extension section (821) and the second extension section (823).

8. The energy storage device (1000) according to claim 1, characterized in that, The disc body portion (81) is further provided with a plurality of first communication holes (812). The plurality of first communication holes (812) all penetrate through the disc body portion (81) along the thickness direction of the disc body portion (81). The plurality of first communication holes (812) are spaced apart from each other, and are all spaced apart from the through hole (811). The sum of the areas of the plurality of first communication holes (812) is S1, and the area of the through hole (811) is S2, and S1 > S2.

9. The energy storage device (1000) according to claim 8, wherein, 21% ≤ S2 / S1 ≤ 52%.

10. The energy storage device (1000) according to claim 8, characterized in that, The disc body portion (81) is further provided with a plurality of second communication holes (814). The plurality of second communication holes (814) all penetrate through the disc body portion (81) along the thickness direction of the disc body portion (81). The plurality of second communication holes (814) are spaced apart from each other, and are spaced apart from the through hole (811) and the plurality of first communication holes (812). The plurality of second communication holes (814) and the plurality of first communication holes (812) are respectively located on both sides of the through hole (811).

11. The energy storage device (1000) according to claim 10, characterized in that, The sum of the areas of the plurality of second communication holes (814) is S3, and S3 > S2.

12. The energy storage device (1000) according to claim 11, characterized in that, 21% ≤ S2 / S3 ≤ 52%.

13. The energy storage device (1000) according to claim 11, characterized in that, S1 = S3.

14. The energy storage device (1000) according to any one of claims 1 to 3, 7 to 13, characterized in that, The electrode assembly has a mandrel, and the mandrel of the electrode assembly is disposed opposite to the through hole (811).

15. An electrical device, characterized in that, The electrical device includes the energy storage device (1000) according to any one of claims 1 to 14, and the energy storage device (1000) supplies power to the electrical device.

Images