Energy storage device and electric device

Abstract

The application provides an energy storage device and an electric equipment, which reduces the probability of fire at the explosion-proof hole of the energy storage device and improves the safety performance of the energy storage device. The energy storage device comprises a shell, an end cover assembly and an electrode assembly. The electrode assembly is accommodated in the shell, the end cover assembly seals the shell and is electrically connected with the electrode assembly. The end cover assembly comprises an end cover provided with an explosion-proof hole. The electrode assembly comprises a plurality of center pole pieces. Each center pole piece has an end face facing the end cover. The distance between each end face and the explosion-proof hole in the height direction of the energy storage device is b. Each center pole piece is provided with a notch groove. The notch grooves of the plurality of center pole pieces enclose an avoidance notch. The projection of the explosion-proof hole on the electrode assembly is located in the avoidance notch. The minimum distance between the notch groove and the explosion-proof hole is a, a > b. The length of the part of the projection of the center pole piece on the end cover which overlaps with the explosion-proof hole is L. The length of the projection of the notch groove on the end cover is D, D ≥ L + 2(a 2 ‑b 2 ) 1 / 2 .

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to an energy storage device and electrical equipment. Background Technology

[0002] As energy storage devices become increasingly widely used, more and more safety issues are emerging, raising concerns about their safety during use. In the event of thermal runaway, existing energy storage devices release large amounts of flammable materials from their electrode components, generating significant heat. These flammable materials, near explosion-proof vents, come into contact with oxygen and are easily ignited under high-temperature conditions, severely impacting the safety performance of the energy storage device. Summary of the Invention

[0003] This application provides an energy storage device and electrical equipment that reduces the probability of fire near the explosion-proof opening of the energy storage device and improves the safety performance of the energy storage device.

[0004] This application provides an energy storage device, including a housing, an end cap assembly, and an electrode assembly. The housing has a receiving cavity and an opening. The receiving cavity is located inside the housing and contains an electrolyte. The opening is located on the top side of the receiving cavity and communicates with the receiving cavity. The electrode assembly is housed in the receiving cavity. The end cap assembly is installed on the housing, closes the opening, and is electrically connected to the electrode assembly. The end cap assembly includes an end cap and an explosion-proof valve. The end cap is provided with an explosion-proof hole that penetrates the end cap along its thickness direction. The explosion-proof valve is installed on the end cap and covers the explosion-proof hole. The electrode assembly includes multiple electrode sheets, which are stacked along the thickness direction of the energy storage device. Each electrode sheet includes multiple center electrode sheets, and each center electrode sheet has an end face facing the end cap. The distance between each end face and the explosion-proof hole along the height direction of the energy storage device is b. Each center electrode sheet has a notch or groove, the opening of which is located on the end face. The notch or groove extends through the center electrode sheet along its thickness direction. The notches or grooves of the multiple center electrode sheets enclose each other to form a clearance notch. The projection of the explosion-proof hole on the electrode assembly is located within the clearance notch and is spaced apart from the edge of the clearance notch. On each of the central electrode plates, the minimum distance between the groove wall and the explosion-proof hole is 'a'. Along the length of the energy storage device, the length of the portion of the projection of the central electrode plate onto the end cover that overlaps with the explosion-proof hole is 'L'. The length of the projection of the groove onto the end cover is 'D', where D ≥ L + 2(a). 2 -b 2 ) 1 / 2 .

[0005] The plurality of central electrode plates include a plurality of first electrode plates, and each first electrode plate has a notch groove including a first groove portion. The projection of the first groove portion on the end cap overlaps with the explosion-proof hole. The minimum depth of the first groove portion is H1, wherein H1≥ab.

[0006] The wall surface of the first groove is parallel to the explosion-proof valve.

[0007] The notch in the first electrode also includes a second groove, which communicates with the first groove. The projection of the second groove on the end cap is misaligned with the explosion-proof hole.

[0008] The plurality of central electrode plates also include a plurality of second electrode plates, wherein the projection of the notch groove of each second electrode plate on the end cap is misaligned with the explosion-proof hole.

[0009] In this configuration, each of the second electrode plates has a minimum position where the distance between the groove wall at the minimum position and the explosion-proof hole is minimized along the thickness direction of the energy storage device, and the minimum distance is M. The depth of the minimum position is H2, where H2 ≥ (a 2 -M 2 ) 1 / 2 -b.

[0010] There are multiple explosion-proof holes, explosion-proof valves, and clearance notches. Each explosion-proof valve covers one explosion-proof hole, and the projection of each explosion-proof hole on the electrode assembly is located within one clearance notch. The edges of the clearance notches are spaced apart.

[0011] The plurality of electrodes also include a plurality of edge electrodes. Along the thickness direction of the energy storage device, a portion of the edge electrodes are located on one side of the plurality of central electrodes, and another portion of the edge electrodes are located on the other side of the plurality of central electrodes.

[0012] The plurality of electrodes include a plurality of anode electrodes and a plurality of cathode electrodes, which are arranged in an alternating stack. The projection of each cathode electrode onto the anode electrode is located within the anode electrode and is spaced apart from the peripheral side surface of the anode electrode.

[0013] The electrode assembly further includes a first electrode tab and a second electrode tab. Along the length of the energy storage device, the first electrode tab and the second electrode tab are located on opposite sides of the clearance notch, and are spaced apart from the clearance notch. They are also electrically connected to the end cap assembly.

[0014] This application also provides an electrical device, including the energy storage device as described above, the energy storage device being used to supply power to the electrical device.

[0015] This application incorporates a notch in each central electrode, with the notches of multiple central electrodes forming a clearance notch. The projection of the explosion-proof hole onto the electrode assembly lies within this clearance notch, spaced apart from its edge. The length of the notch is also limited. This design increases the distance between the central electrode and the explosion-proof hole, extending the distance between the combustibles generated by the electrode assembly and the high-temperature environment of the electrode assembly, and the oxygen supply outside the explosion-proof hole. This reduces the probability of fire near the explosion-proof hole, improves the safety performance of the energy storage device, minimizes the impact of the clearance notch on the electrode's energy density, ensures the electrode's current transmission capacity, and improves product yield. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be described below.

[0017] Figure 1 This is a schematic diagram of the structure of an energy storage system according to an embodiment of this application; Figure 2 This is a schematic diagram of the energy storage device provided in the embodiments of this application; Figure 3 yes Figure 2 The diagram shows an exploded view of the energy storage device in the first embodiment. Figure 4 yes Figure 2 The diagram shows the structure of the energy storage device after being cut along point AA in the first embodiment. Figure 5 yes Figure 4 A schematic diagram of some structures in the energy storage device shown; Figure 6 yes Figure 5 A partially enlarged schematic diagram of the energy storage device shown; Figure 7 yes Figure 3 The diagram shows the structure of the end cap in the end cap assembly. Figure 8 yes Figure 3 The diagram shows the structure of the lower insulating component in the end cap assembly. Figure 9 yes Figure 3 A schematic diagram of the planar structure of the anode and cathode electrodes in the electrode assembly shown. Figure 10 yes Figure 5 A schematic diagram of the cross-sectional structure along point BB; Figure 11 yes Figure 2 The diagram shows a partially exploded structure of the energy storage device in the second embodiment.

[0018] Reference numerals: Energy storage system 1, High-voltage cable 2, First power conversion device 3, Second power conversion device 4, Energy storage device 1000, Housing 100, Electrode assembly 300, End cap assembly 500, Receiving cavity 105, Opening 110, End cap 510, Explosion-proof valve 520, Protective plate 530, Lower insulating component 540, Electrode post 550, Upper insulating component 560, Pin 570, Sealing ring 580, Explosion-proof hole 511, First electrode post hole 512, Through hole 541, Second electrode post hole 542, Clearance notch Q, Electrode 310, Anode electrode 311, Cathode electrode 312, Center electrode 320, Edge electrode 330, End face 322, Notch groove 321, First electrode 324, Second electrode 327, First groove 326a, Second groove 326b, Minimum position 329a, First tab 350, Second tab 360. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] Because the energy we need is highly time- and space-dependent, in order to utilize energy rationally and improve energy efficiency, it is necessary 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 for future applications. Currently, the main way to generate green electricity is to develop green energy sources such as photovoltaics and wind power to replace fossil fuels. Currently, the generation of green electricity generally relies on solar, wind, and hydropower. However, wind and solar power are generally characterized by strong intermittency and large fluctuations, which can cause grid instability, insufficient power during peak demand periods, and excessive power during off-peak periods. Unstable voltage can also damage the power grid. Therefore, insufficient electricity demand or insufficient grid capacity may lead to the problem of "wind and solar curtailment." Solving these problems requires energy storage. This involves converting electrical energy into other forms of energy through physical or chemical means and storing it. When needed, this energy can be converted back into electrical energy and released. Simply put, energy storage is like a large "power bank," storing electrical energy when solar and wind power are abundant and releasing the stored electricity when needed.

[0021] Taking electrochemical energy storage as an example, this solution provides an energy storage device for use in energy storage systems. The energy storage device is equipped with a set of chemical batteries, which mainly use the chemical elements in the batteries as energy storage media. The charging and discharging process is accompanied by the chemical reaction or change of the energy storage media. Simply put, the electrical energy generated by wind and solar energy is stored in the chemical batteries. When the use of external electrical energy reaches its peak, the stored electricity is released for use, or transferred to places with a shortage of electricity for use.

[0022] Current energy storage applications are quite widespread, including generation-side energy storage, grid-side energy storage, and consumption-side energy storage. The corresponding types of energy storage devices include: Large-scale energy storage power stations applied to wind and solar power plants can assist renewable energy generation in meeting grid connection requirements and improve the utilization rate of renewable energy. As a high-quality active / reactive power source on the power supply side, energy storage power stations can achieve load matching of electricity in time and space, enhance the absorption capacity of renewable energy, reduce instantaneous power fluctuations, reduce the impact on the power grid, improve the absorption of new energy generation, and are of great significance in grid system backup, alleviating peak load power supply pressure, and peak and frequency regulation. Energy storage containers used on the grid side mainly function as peak shaving, frequency regulation, and grid congestion relief. In terms of peak shaving, they can achieve peak shaving and valley filling of electricity load, that is, charging the energy storage battery when the electricity load is low and releasing the stored electricity during the peak electricity load period, thereby achieving a balance between power production and consumption. Small-scale energy storage cabinets applied to the electricity consumption side primarily function to facilitate self-consumption of electricity, peak-valley price arbitrage, capacity cost management, and improve power supply reliability. Depending on the application scenario, electricity consumption-side energy storage can be categorized into commercial and industrial energy storage cabinets, residential energy storage devices, and energy storage charging piles, generally used in conjunction with distributed photovoltaic (PV) systems. Commercial and industrial users can utilize energy storage for peak-valley price arbitrage and capacity cost management. In electricity markets implementing peak-valley pricing, charging the energy storage system during low electricity prices and discharging it during high electricity prices allows for arbitrage, reducing electricity costs. Furthermore, industrial enterprises subject to two-part tariffs can utilize energy storage systems to store energy during off-peak hours and discharge it during peak load periods, thereby reducing peak power and the maximum declared demand, ultimately lowering capacity costs. Residential PV systems combined with energy storage can improve self-consumption levels. High electricity prices and poor power supply stability drive demand for residential PV installations. Given that photovoltaic power generation occurs during the day, while user load is generally higher at night, configuring energy storage can better utilize photovoltaic power, improve self-consumption levels, and reduce electricity costs. Furthermore, energy storage is needed in areas such as communication base stations and data centers for backup power.

[0023] In some embodiments, see Figure 1 , Figure 1This is a schematic diagram of the structure of an energy storage system 1 according to an embodiment of this application, and this application Figure 1 The embodiments are illustrated using a shared energy storage scenario on the generation / distribution side as an example. The energy storage device 1000 of this application is not limited to its generation / distribution side energy storage scenario.

[0024] This application provides an energy storage system 1, which includes: a high-voltage cable 2, a first power conversion device 3, a second power conversion device 4, and an energy storage device 1000. In some embodiments of the power generation scenario, the second power conversion device 4 can be a wind power conversion device. Since the electricity generated by wind power conversion is volatile, random, and intermittent, the unstable electricity output by the wind power conversion device can be stored in the energy storage device 1000 through grid connection. The energy storage device 1000 is connected to the high-voltage cable 2 and outputs smooth electricity to the power consumption side of the distribution network, realizing peak shaving and frequency regulation, and stable grid operation; or, the wind power conversion device is always connected to the high-voltage cable 2. High-voltage cable 2 connects the wind power conversion device to the power distribution network under normal power generation conditions. When the current power load is low and the wind power conversion device generates excess power, the excess power is first stored in energy storage device 1000 to reduce wind and solar curtailment and improve the absorption of new energy power generation. When the power load is high, the power grid issues an instruction to transmit the power stored in energy storage device 1000 together with high-voltage cable 2 in grid-connected mode to supply power to the power consumption side. This provides the power grid with various services such as peak shaving, frequency regulation, and backup, giving full play to the peak shaving function of the power grid, promoting peak shaving and valley filling, and alleviating the power supply pressure of the power grid.

[0025] In some embodiments on the distribution network side, the first power conversion device 3 can be a photovoltaic power conversion device. The energy storage device 1000 is connected to the high-voltage cable 2 and installed downstream of the high-voltage cable 2 between the user load and the user load. The power output by the photovoltaic power conversion device is stored in the energy storage device 1000, which can respond in a timely manner to act as a backup power source when the power grid / distribution network fails. Alternatively, it can provide power supply support to alleviate line congestion when the high-voltage cable 2 transmission line is blocked, and to delay the economic pressure caused by the expansion of the power grid / distribution capacity when the power grid is planned to be expanded.

[0026] Optionally, the first power conversion device may include, but is not limited to, a wind power conversion device, and the second power conversion device may include, but is not limited to, a photovoltaic power conversion device. The first power conversion device 3 and the second power conversion device 4 can convert at least one of solar energy, light energy, wind energy, thermal energy, tidal energy, biomass energy, and mechanical energy into electrical energy.

[0027] Optionally, the energy storage device 1000 may include, but is not limited to, energy storage applications such as energy storage power stations, hydropower / thermal / wind power generation systems, solar power generation systems, mobile power systems, smart home systems, or temporary power supply systems, and may also be applied in multiple fields such as data centers, military equipment, aerospace, charging piles, and electric vehicles.

[0028] Please see Figure 2 , Figure 2 This is a schematic diagram of the structure of the energy storage device 1000 provided in the embodiments of this application.

[0029] This application provides an energy storage device 1000, which may include, but is not limited to, single-cell batteries, battery modules, battery packs, and battery systems. The single-cell battery can be a rechargeable battery, meaning a battery that can be reactivated by charging after discharge and continue to be used. Single-cell batteries can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc., and this application does not specifically limit their types. The actual application form of the energy storage device provided in this application embodiment can be, but is not limited to, the listed products, and can also be other application forms. This application embodiment does not strictly limit the application form of the energy storage device 1000. This application embodiment uses a square battery as an example to illustrate the energy storage device 1000.

[0030] Please refer to the following: Figures 3 to 5 , Figure 3 yes Figure 2 The diagram shows an exploded view of the energy storage device 1000 in a first embodiment. Figure 4 yes Figure 2 The diagram shows the structure of the energy storage device 1000 after being cut along point AA in the first embodiment. Figure 5 yes Figure 4 A schematic diagram of part of the structure of the energy storage device shown.

[0031] The energy storage device 1000 includes a housing 100, an electrode assembly 300, and an end cap assembly 500. The housing 100 has a receiving cavity 105 and an opening 110. The receiving cavity 105 is located inside the housing 100 and contains an electrolyte. The opening 110 is located on the top side of the receiving cavity 105 and communicates with it. The housing 100 may be an aluminum shell made of aluminum. The electrode assembly 300 is housed in the receiving cavity 105 and can be immersed in the electrolyte. The end cap assembly 500 is mounted on the housing 100, closes the opening 110, and is electrically connected to the electrode assembly 300.

[0032] Please refer to the following: Figure 6 , Figure 6 yes Figure 5A partially enlarged schematic diagram of the energy storage device 1000 shown.

[0033] The end cap assembly 500 includes an end cap 510, an explosion-proof valve 520, a protective plate 530, a lower insulator 540, a pole 550, an upper insulator 560, a pin 570, and a sealing ring 580. The explosion-proof valve 520 and the protective plate 530 are both mounted on the end cap 510. Along the thickness direction of the end cap 510, the lower insulator 540 is mounted on one side of the end cap 510. The pole 550 passes through the end cap 510 and the lower insulator 540. There are two poles 550. Along the length direction of the end cap assembly 500, the two poles 550 are arranged at intervals. One pole 550 serves as the positive pole, and the other pole 550 serves as the negative pole. The upper insulator 560 is mounted on the side of the end cap 510 opposite to the lower insulator 540. There are two upper insulators 560. One upper insulating member 560 serves as the positive upper insulating member, and the other upper insulating member 560 serves as the negative upper insulating member. A pin 570 is located on the side of the lower insulating member 540 opposite to the end cover 510 and is electrically connected to the terminal post 550 and the tab of the electrode assembly 300 to facilitate current conduction in the energy storage device 1000. There are two pins 570. One pin 570 serves as the positive pin and is electrically connected to the positive terminal post and the positive tab of the electrode assembly. The other pin 570 serves as the negative pin and is electrically connected to the negative terminal post and the negative tab of the electrode assembly. A sealing ring 580 is fitted onto the terminal post 550 and clamped between the end cover 510 and the terminal post 550. There are two sealing rings 580; one sealing ring 580 serves as the positive sealing ring 580, fitted onto the positive terminal post and clamped between the end cover 510 and the positive terminal post. Another sealing ring 580 serves as a negative electrode sealing ring 580, and is fitted onto the negative electrode post and clamped between the end cap 510 and the negative electrode post.

[0034] Please see Figure 7 , Figure 7 yes Figure 3 The diagram shows the structure of end cap 510 in end cap assembly 500.

[0035] The end cap 510 is provided with an explosion-proof hole 511 and a first pole post hole 512. Both the explosion-proof hole 511 and the first pole post hole 512 penetrate the end cap 510 along its thickness direction. The explosion-proof hole 511 communicates with the exhaust channel to form a closed loop, allowing gas inside the energy storage device 1000 to be discharged to the outside of the energy storage device 1000. In this embodiment, there is one explosion-proof hole 511, located at the middle of the length direction of the end cap 510.

[0036] Along the length of the end cap 510, the first electrode post hole 512 is located on one side of the explosion-proof hole 511 and is spaced apart from the explosion-proof hole 511. There are two first electrode post holes 512. Along the length of the end cap 510, the two first electrode post holes 512 are located on opposite sides of the explosion-proof hole 511. One first electrode post hole 512 allows the positive electrode post 550 to pass through, and the other first electrode post hole 512 allows the negative electrode post 550 to pass through.

[0037] Please continue reading. Figure 4 An explosion-proof valve 520 is installed on the end cap 510 and covers the explosion-proof hole 511. When the internal gas pressure of the energy storage device 1000 is too high and the explosion-proof valve 520 is opened, the gas can flow smoothly from the exhaust channel to the explosion-proof hole 511, and then be discharged to the outside of the energy storage device 1000, since the explosion-proof hole 511 is connected to the exhaust channel. The lower insulating member 540 is located on the side of the end cap 510 facing the electrode assembly 300.

[0038] Please see Figure 8 , Figure 8 yes Figure 3 A schematic diagram of the structure of the lower insulating member 540 in the end cap assembly 500 shown.

[0039] The lower insulating member 540 is provided with a through hole 541 and a second pole hole 542. Both the through hole 541 and the second pole hole 542 penetrate the lower insulating member 540 along its thickness direction. The through hole 541 communicates with the explosion-proof hole 511, allowing gas inside the energy storage device 1000 to flow out through the through hole 541 to the explosion-proof valve 520. Then, as the explosion-proof valve 520 opens, the gas flows through the explosion-proof hole 511 to the outside of the energy storage device 1000. The second pole hole 542 is located on one side of the through hole 541 and is spaced apart from it, communicating with the first pole hole 512. There are two second pole holes 542. Along the length of the lower insulating member 540, the two second pole holes 542 are located on opposite sides of the through hole 541.

[0040] Each pole piece 550 passes through a first pole piece hole 512 and a second pole piece hole 542. Each pin 570 is fixedly connected to a pole piece 550. Each sealing ring 580 is fitted onto a pole piece 550 and clamped between the end cap 510 and a pole piece 550. The sealing ring 580 not only seals the gap between the upper and lower insulating components 540, ensuring good airtightness of the end cap assembly 500, but also insulates the end cap 510 from the pole piece 550.

[0041] Please continue reading. Figure 3 and Figure 6The electrode assembly 300 is provided with a clearance notch Q. The projection of the explosion-proof hole 511 on the electrode assembly is located within the clearance notch Q and is spaced apart from the edge of the clearance notch Q. In this embodiment, there is one clearance notch Q. The clearance notch Q is correspondingly provided with the explosion-proof hole 511, and the projection of the explosion-proof hole 511 on the electrode assembly 300 is located within the clearance notch Q and is spaced apart from the edge of the clearance notch Q. With this arrangement, the distance between the electrode assembly 300 and the explosion-proof hole 511 near each explosion-proof hole 511 can be increased, thereby extending the distance between the combustibles and high-temperature environment generated by the electrode assembly 300 and the external combustion-supporting gas of the explosion-proof hole 511, thereby reducing the probability of the energy storage device 1000 igniting at the explosion-proof hole 511 and improving the safety performance of the energy storage device 1000.

[0042] Please refer to the following: Figure 9 , Figure 9 yes Figure 3 A schematic diagram of the planar structure of the anode electrode 311 and the cathode electrode 312 in the electrode assembly shown.

[0043] The electrode assembly 300 includes multiple electrodes 310 and multiple diaphragms (not shown). The electrodes 310 are stacked along the thickness direction of the electrode assembly 300, which is parallel to the thickness direction of the energy storage device 1000. Each electrode 310 includes multiple anode electrodes 311 and multiple cathode electrodes 312. The anode electrodes 311 and cathode electrodes 312 are staggered along the thickness direction of the electrode assembly 300. The projection of each cathode electrode 312 onto the anode electrode 311 is located within the anode electrode 311 and is spaced apart from the peripheral surface of the anode electrode 311. This arrangement ensures that the projection of the anode electrode 311 onto the cathode electrode 312 completely covers the cathode electrode 312 along the thickness direction of the electrode assembly 300, allowing the cathode electrode 312 to have corresponding points on the anode electrode 311 for ion movement. It should be noted that when the anode electrode 311 and cathode electrode 312 are placed in the electrolyte, and the anode electrode 311 and cathode electrode 312 are charged for the first time, the cathode electrode 312 will release cations. Under the action of the electric field, the cations move towards the anode electrode 311. The projection of the anode electrode 311 onto the cathode electrode 312 completely covers the cathode electrode 312, and the boundary of the projection of the cathode electrode 312 onto the anode electrode 311 is spaced apart from the anode electrode 311. This ensures that the cations released by the cathode electrode 312 have a point of movement on the anode electrode 311, avoiding the formation of cation dendrite structures at the edge of the anode electrode 311. This ensures the charging and discharging process of the energy storage device 1000 and helps to improve the service life and safety performance of the energy storage device 1000.

[0044] The plurality of electrode plates 310 also includes a plurality of central electrode plates 320 and a plurality of edge electrode plates 330. The plurality of central electrode plates 320 are stacked along the thickness direction of the electrode assembly 300 and are located in the middle of the energy storage device 1000. A portion of the edge electrode plates 330 are located on one side of the plurality of central electrode plates 320, and another portion of the edge electrode plates 330 are located on the other side of the plurality of central electrode plates 320.

[0045] Each central electrode 320 has an end face 322 facing the end cap 510. Along the height direction of the energy storage device 1000, the distance between each end face 322 and the explosion-proof hole 511 is b, where b ≥ 3 mm. Each central electrode 320 is provided with a notch 321. The opening of the notch 321 is located on the end face 322. The notch 321 penetrates the central electrode 320 along its thickness direction. The notches 321 of multiple central electrodes 320 enclose a clearance notch Q, the projection of the clearance notch Q onto the electrode assembly is located within the clearance notch Q, and is spaced apart from the edge of the clearance notch. On each central electrode 320, the minimum distance between the groove wall of the notch 321 and the explosion-proof hole 511 is a, where a > b, and 5 mm ≤ a ≤ 100 mm. Along the length of the energy storage device 1000, the length of the portion of the projection of the central electrode 320 onto the end cover 510 that overlaps with the explosion-proof hole 511 is L, and the length of the projection of the notch 321 onto the end cover 510 is D, where D ≥ L + 2 (a 2 -b 2 ) 1 / 2 .

[0046] For details, please refer to Figure 6 On each central electrode 320, the distance between the groove wall of the notch 321 and the explosion-proof hole 511 must be greater than or equal to *a*. Along the length of the energy storage device 1000, the minimum distance between the edge of the notch 321 and the explosion-proof hole 511 is *a*. Furthermore, along the height of the energy storage device 1000, the distance between the end face 322 of the central electrode 320 and the explosion-proof hole 511 is *b*. According to the Pythagorean theorem, the projection of the notch 321 onto the end cap 510 must exceed the length of the explosion-proof hole 511 by more than or equal to 2(a*b*). 2 -b 2 ) 1 / 2 Furthermore, since the length of the portion of the projection of the central electrode 320 onto the end cover 510 that overlaps with the explosion-proof hole 511 along the length of the energy storage device 1000 is L, the length of the projection of the notch 321 onto the end cover 510 is D, and D≥L+2(a 2 -b 2 ) 1 / 2 .

[0047] It should be noted that the range of D can be calculated based on the values ​​of a and b. Under the premise of ensuring that the minimum distance between the two ends of the notch 321 and the explosion-proof hole 511 in the length direction is a, D can be calculated to facilitate the cutting of the notch based on the value of D. This ensures that the notch 321 of each central electrode 320 can completely cover the length of the explosion-proof hole 511 in the length direction of the end cap 510, thereby increasing the distance between the wall of the notch 321 and the wall of the explosion-proof hole 511. This extends the distance between the combustibles and high-temperature environment generated by the central electrode 320 and the external combustion-supporting gas of the explosion-proof hole 511, thereby reducing the probability of the energy storage device 1000 igniting at the explosion-proof hole 511, improving the safety performance of the energy storage device 1000, and reducing the impact of the notch 321 on the current transmission on the central electrode 320, thus ensuring the performance of the central electrode 320.

[0048] The plurality of center electrodes 320 includes a plurality of first electrodes 324 and a plurality of second electrodes 327. Along the thickness direction of the electrode assembly 300, a portion of the second electrodes 327 are located on one side of the plurality of first electrodes 324, and another portion of the second electrodes 327 are located on the other side of the plurality of first electrodes 324.

[0049] Along the height of the energy storage device 1000, the distance between the end face 322 of the first electrode 324 and the explosion-proof hole 511 is b1, where b1 ≥ 3mm. This ensures a certain assembly distance between the electrode assembly 300 and the end cap 510, facilitating the installation of the electrode assembly 300. It should be noted that in the first electrode 324, b1 represents the distance b between the end face 322 and the explosion-proof hole 511.

[0050] The minimum distance between the groove wall of the notch 321 of the first electrode 324 and the explosion-proof hole 511 is a1. Where 5mm ≤ a1 ≤ 100mm, and a1 > b1, this increases the distance between the wall of the notch 321 of the first electrode 324 and the wall of the explosion-proof hole 511, extending the distance between the combustible material and high-temperature environment generated by the first electrode 324 and the external combustion-supporting gas of the explosion-proof hole 511. This reduces the probability of the energy storage device 1000 igniting at the explosion-proof hole 511, improving the safety performance of the energy storage device 1000. It should be noted that in the first electrode 324, a1 represents the minimum distance 'a' between the groove wall of the notch 321 and the explosion-proof hole 511.

[0051] Along the length of the end cap 510, the length of the portion of the projection of each first electrode 324 onto the end cap 510 that overlaps with the explosion-proof hole 511 is L. Along the length of the electrode assembly 300, the length of the notch 321 of the first electrode 324 is D1. Where D1 ≥ L + 2(a1) 2 -b1 2 ) 1 / 2It should be noted that in the first electrode 324, D1 represents the length D of the notch 321 in the length direction of the electrode assembly 300.

[0052] Please refer to the following: Figure 10 , Figure 10 yes Figure 5 A schematic diagram of the cross-sectional structure along point BB.

[0053] Meanwhile, each first electrode 324 has a notch 321 including a first groove 326a and a second groove 326b. The projection of the first groove 326a onto the end cap 510 overlaps with the explosion-proof hole 511. The minimum depth of the first groove 326a is H1, where H1 ≥ a1 - b1. With this configuration, the minimum depth of the first groove 326a can be guaranteed to meet the requirement of H1. Therefore, the distance between each point on the groove wall of the first groove 326a and the explosion-proof hole 511 is greater than H1, thereby extending the distance between the groove wall of the first groove 326a and the explosion-proof hole 511. This increases the distance between the combustible material and high-temperature environment generated by the first groove 326a and the external combustion-supporting gas of the explosion-proof hole 511, thereby reducing the probability of the energy storage device 1000 igniting at the explosion-proof hole 511 and improving the safety performance of the energy storage device 1000. Preferably, the groove wall of the first groove 326a is parallel to the explosion-proof valve 520, which can maximize the uniformity of the first electrode 324, reduce the influence of the notch 321 of the first electrode 324 on the current transmission on the first electrode 324, and improve the performance of the first electrode 324.

[0054] The second groove 326b is connected to the first groove 326a. The projection of the second groove 326b on the end cap 510 is offset from the explosion-proof hole 511, that is, the projection of the second groove 326b on the end cap 510 does not overlap with the explosion-proof hole 511. The minimum distance between the groove wall of the second groove 326b and the explosion-proof hole 511 is a1, where 5mm≤a1≤100mm. The first groove 326a and the second groove 326b are designed separately, which can reduce the probability of fire near the explosion-proof hole 511 of the energy storage device 1000, while reducing the impact of the notch 321 of the first electrode 324 on the current energy density of the first electrode 324, thereby ensuring the performance of the first electrode 324.

[0055] The setting of the notch 321 parameter of the first electrode 324 can increase the distance between the first electrode 324 and the explosion-proof hole 511, extending the distance between the combustibles generated by the electrode assembly 300 and the high-temperature environment of the electrode assembly 300 and the combustion-supporting oxygen outside the explosion-proof hole 511. This can reduce the probability of the energy storage device 1000 catching fire at the explosion-proof hole 511, improve the safety performance of the energy storage device 1000, and at the same time reduce the impact of the notch 321 of the first electrode 324 on the current energy density of the first electrode 324, thereby ensuring the performance of the first electrode 324.

[0056] It should be noted that the shape of the notch 321 of the first electrode 324 can be arbitrary. As long as the size of the portion corresponding to the first electrode 324 and the explosion-proof hole 511 can be reduced, the distance between the first electrode 324 and the explosion-proof hole 511 can be extended to reduce the probability of fire at the explosion-proof hole 511 in the energy storage device 1000. This application does not impose any restrictions on this. For example, the notch 321 is arc-shaped.

[0057] It should be noted that the multiple first electrodes 324 include multiple anode electrodes 311 and multiple cathode electrodes 312. In two adjacent first electrodes 324, the projection of the cathode electrode 312 onto the anode electrode 311 is completely located within the anode electrode 311, and the boundary of the projection of the cathode electrode 312 onto the anode electrode 311 is spaced apart from the anode electrode 311. This arrangement ensures that the cations released from the cathode electrode 312 have a movable point on the anode electrode 311, avoiding the formation of cation dendrite structures at the edge of the anode electrode 311, ensuring the charging and discharging process of the energy storage device 1000, and improving the service life and safety performance of the energy storage device 1000.

[0058] Along the height direction of the energy storage device 1000, the distance between the end face 322 of each second electrode 327 and the explosion-proof hole 511 is b2. It should be noted that, in the second electrode 327, b2 represents the distance b between the end face 322 and the explosion-proof hole 511.

[0059] The projection of the notch 321 of each second electrode 327 onto the end cap 510 is offset from the explosion-proof hole 511. The minimum distance between the groove wall of the notch 321 of the second electrode 327 and the explosion-proof hole 511 is a2. Where a2 > b2, 5mm ≤ a2 ≤ 100mm. It should be noted that in the second electrode 327, a2 represents the minimum distance a between the groove wall of the notch 321 and the explosion-proof hole 511.

[0060] The notch 321 of the second electrode 327 increases the distance between the second electrode 327 and the explosion-proof hole 511, further extending the distance between the combustibles generated by the electrode assembly 300 and the high-temperature environment of the electrode assembly 300 and the oxygen supporting combustion outside the explosion-proof hole 511. This reduces the probability of the energy storage device 1000 catching fire at the explosion-proof hole 511 and improves the safety performance of the energy storage device 1000.

[0061] Along the length of the electrode assembly 300, the length L of the portion of each second electrode 327 overlapping with the explosion-proof hole 511 in its projection on the end cap 510 is 0 mm. At this time, the length of the notch 321 of the second electrode 327 is D2, where D2 ≥ 2 (a2) 2 -b2 2 )1 / 2 .

[0062] Each second electrode 327 has a notch 321 with a minimum position 329a. Along the thickness direction of the energy storage device 1000, the distance between the groove wall of the minimum position 329a and the explosion-proof hole 511 is minimal, and the minimum distance is M. The depth of the minimum position 329a is H2, where H2 ≥ (a2) / (a2) 2 -M 2 ) 1 / 2 -b2. For details, please refer to [link / reference]. Figure 10 The distance between the minimum position 329a of the notch 321 of each second electrode 327 and the explosion-proof hole 511 needs to be greater than or equal to a2. Also, along the thickness direction of the energy storage device 1000, the distance between the groove wall of the minimum position 329a and the explosion-proof hole 511 is M. Therefore, according to the Pythagorean theorem, along the height direction of the energy storage device 1000, the distance between the minimum position 329a and the explosion-proof hole 511 is greater than or equal to (a2). 2 -M 2 ) 1 / 2 Furthermore, since the distance between the end face 322 of the central electrode 320 and the explosion-proof hole 511 along the height direction of the energy storage device 1000 is b, the depth H2 of the minimum position 329a on the notch 321 of the second electrode 327 is H2 ≥ (a2) / (b). 2 -M 2 ) 1 / 2 -b2. Calculate H2 based on a2, b2 and M. Under the condition that the distance between the minimum position 329a of the second electrode 327 and the explosion-proof hole 511 is greater than or equal to a, calculate the depth H2 of the minimum position 329a so as to facilitate cutting the notch 321 of each second electrode 327 according to H2.

[0063] The arrangement of D2 and H2 extends the distance between the area corresponding to each second electrode 327 and the explosion-proof hole 511, while reducing the impact of the notch 321 of the second electrode 327 on the current energy density of the second electrode 327. This increases the distance between the combustibles and high-temperature environment generated by the second electrode 327 and the external combustion-supporting gas of the explosion-proof hole 511, thereby reducing the probability of the energy storage device 1000 igniting at the explosion-proof hole 511, improving the safety performance of the energy storage device 1000, and also ensuring the performance of the second electrode 327.

[0064] It should be noted that the clearance notch Q includes notches 321 of multiple second electrode plates 327 and notches 321 of multiple first electrode plates 324. The setting of the clearance notch Q can extend the distance between the electrode plates near the explosion-proof hole 511 and the explosion-proof hole 511, increase the distance between the combustibles and high-temperature environment generated by the electrode plates and the external combustion-supporting gas of the explosion-proof hole 511, thereby reducing the probability of the energy storage device 1000 igniting at the explosion-proof hole 511 and improving the safety performance of the energy storage device 1000.

[0065] It should be noted that the multiple second electrodes 327 include multiple anode electrodes 311 and multiple cathode electrodes 312. In two adjacent second electrodes 327, the projection of the cathode electrode 312 onto the anode electrode 311 is completely within the anode electrode 311, and the boundary of the projection of the cathode electrode 312 onto the anode electrode 311 is spaced apart from the anode electrode 311. This arrangement ensures that the cations released from the cathode electrode 312 have a moving point on the anode electrode 311, avoiding the formation of cation dendrite structures at the edge of the anode electrode 311, ensuring the charging and discharging process of the energy storage device 1000, and improving the service life and safety performance of the energy storage device 1000.

[0066] Along the thickness direction of the electrode assembly 300, a portion of the edge electrodes 330 are located on the side of a portion of the second electrodes 327 facing away from the plurality of first electrodes 324, and another portion of the edge electrodes 330 are located on the side of another portion of the second electrodes 327 facing away from the plurality of first electrodes 324. None of the edge electrodes 330 have notches 321, and they are located on opposite sides of the central electrode 320, thereby improving the performance of the electrode assembly 300.

[0067] Multiple edge electrodes 330 may include multiple anode electrodes 311 and multiple cathode electrodes 312. In two adjacent edge electrodes 330, the projection of the cathode electrode 312 onto the anode electrode 311 is completely located within the anode electrode 311, and the boundary of the projection of the cathode electrode 312 onto the anode electrode 311 is spaced apart from the anode electrode 311. This arrangement ensures that the cations released from the cathode electrode 312 have a moving point on the anode electrode 311, avoiding the formation of cation dendrite structures at the edge of the anode electrode 311, ensuring the charging and discharging process of the energy storage device 1000, and improving the service life and safety performance of the energy storage device 1000.

[0068] The electrode assembly 300 also includes a first tab 350 and a second tab 360. Along the length of the energy storage device 1000, the first tab 350 and the second tab 360 are located on opposite sides of the clearance notch Q, and are spaced apart from the clearance notch Q, and are electrically connected to the end cap assembly 500. This arrangement maintains the symmetry of the electrode assembly 300, which is beneficial for ensuring the uniformity of current transmission. For example, the first tab 350 serves as a positive tab and is electrically connected to the positive pin, and the second tab 360 serves as a negative tab and is electrically connected to the negative pin.

[0069] Specifically, each anode electrode 311 includes a first sub-tab. The first tab 350 includes first sub-tabs for multiple anode electrodes. Each cathode electrode 312 includes a second sub-tab. The second tab 360 includes second sub-tabs for multiple cathode electrodes.

[0070] Along the thickness direction of the electrode assembly 300, each diaphragm is located between two adjacent electrodes 310. Specifically, each diaphragm is located between an anode electrode 311 and a cathode electrode 312.

[0071] Please see Figure 11 , Figure 11 yes Figure 2 The diagram shows a partially exploded view of the energy storage device 1000 in the second embodiment.

[0072] This embodiment differs from the first embodiment in that there can be multiple explosion-proof valves 520 and explosion-proof holes 511, with each explosion-proof valve 520 covering one explosion-proof hole 511. The number of explosion-proof valves 520 is the same as the number of explosion-proof holes 511. This application does not impose any limitation on this. Meanwhile, there can be multiple clearance notches Q. The number of clearance notches Q is the same as the number of explosion-proof holes 511 and explosion-proof valves 520. Each clearance notch Q corresponds to one explosion-proof hole 511, and the projection of each explosion-proof hole 511 on the electrode assembly 300 is located within one clearance notch Q and is spaced apart from the edge of the clearance notch Q.

[0073] With this configuration, while improving the venting performance of the energy storage device 1000, the distance between the electrode assembly 300 and the explosion-proof hole 511 near each explosion-proof hole 511 can be increased. This extends the distance between the combustibles and high-temperature environment generated by the electrode assembly 300 and the external combustion-supporting gas of the explosion-proof hole 511, further reducing the probability of the energy storage device 1000 catching fire at the explosion-proof hole 511 and improving the safety performance of the energy storage device 1000.

[0074] This application provides a notch 321 in each central electrode 320, and the notches 321 of multiple central electrode 320s enclose a clearance notch Q. The projection of the explosion-proof hole 511 on the electrode assembly 300 is located within the clearance notch Q and spaced apart from the edge of the clearance notch Q. Simultaneously, the length of the notch 321 is limited. This arrangement increases the distance between the central electrode 320 and the explosion-proof hole 511, extending the distance between the combustibles generated by the electrode assembly 300 and the high-temperature environment of the electrode assembly 300 and the oxygen supply outside the explosion-proof hole 511. This reduces the probability of the energy storage device 1000 igniting near the explosion-proof hole 511, improves the safety performance of the energy storage device 1000, reduces the impact of the clearance notch Q on the energy density of the electrode 310, ensures the electrode's current transmission capability, and improves the product's yield.

[0075] This embodiment also provides an electrical device, such as an energy storage cabinet or a new energy vehicle. This electrical device includes the energy storage device 1000 described in the above embodiment, which supplies power to the electrical device. Since the specific structure and technical effects of the energy storage device 1000 have already been described in detail above, they will not be repeated here. The electrical device provided in this embodiment, by incorporating the aforementioned energy storage device 1000, improves the exhaust performance and operational safety and reliability of the electrical device.

[0076] The above descriptions are merely optional embodiments of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of this application and are not intended to limit the patent scope of this application. At the same time, for those skilled in the art, equivalent structural transformations made based on the concept of this application and using the specification and drawings of this application, or direct / indirect applications in other related technical fields, all fall within the patent protection scope of this application.

Claims

1. An energy storage device, characterized in that, The device includes a housing, an end cap assembly, and an electrode assembly. The housing has a receiving cavity and an opening. The receiving cavity is located inside the housing and contains an electrolyte. The opening is located on the top side of the receiving cavity and communicates with the receiving cavity. The electrode assembly is housed in the receiving cavity. The end cap assembly is mounted on the housing, closes the opening, and is electrically connected to the electrode assembly. The end cap assembly includes an end cap and an explosion-proof valve. The end cap is provided with an explosion-proof hole that penetrates the end cap along its thickness direction. The explosion-proof valve is installed on the end cap and covers the explosion-proof hole. The electrode assembly includes multiple electrode sheets, which are stacked along the thickness direction of the energy storage device. Each electrode sheet includes multiple center electrode sheets, and each center electrode sheet has an end face facing the end cap. The distance between each end face and the explosion-proof hole along the height direction of the energy storage device is b. Each center electrode sheet has a notch or groove, the opening of which is located on the end face. The notch or groove extends through the center electrode sheet along its thickness direction. The notches or grooves of the multiple center electrode sheets enclose each other to form a clearance notch. The projection of the explosion-proof hole on the electrode assembly is located within the clearance notch and is spaced apart from the edge of the clearance notch. On each of the central electrode plates, the minimum distance between the groove wall and the explosion-proof hole is 'a'. Along the length of the energy storage device, the length of the portion of the projection of the central electrode plate onto the end cover that overlaps with the explosion-proof hole is 'L'. The length of the projection of the groove onto the end cover is 'D', where D ≥ L + 2(a). 2 -b 2 ) 1 / 2 .

2. The energy storage device according to claim 1, characterized in that, The plurality of central electrode plates include a plurality of first electrode plates, and the notch of each first electrode plate includes a first groove portion. The projection of the first groove portion on the end cap overlaps with the explosion-proof hole. The minimum depth of the first groove portion is H1, wherein H1≥ab.

3. The energy storage device according to claim 2, characterized in that, The wall surface of the first groove is parallel to the explosion-proof valve.

4. The energy storage device according to claim 2, characterized in that, The notch in the first electrode also includes a second groove, which communicates with the first groove. The projection of the second groove on the end cap is offset from the explosion-proof hole.

5. The energy storage device according to claim 1, characterized in that, The plurality of central electrode plates also include a plurality of second electrode plates, wherein the projection of the notch groove of each second electrode plate on the end cap is misaligned with the explosion-proof hole.

6. The energy storage device according to claim 5, characterized in that, Each second electrode has a notch slot with a minimum position. Along the thickness direction of the energy storage device, the distance between the slot wall at the minimum position and the explosion-proof hole is minimized, and the minimum distance is M. The depth of the minimum position is H2, where H2 ≥ (a 2 -M 2 ) 1 / 2 -b.

7. The energy storage device according to any one of claims 1 to 6, characterized in that, There are multiple explosion-proof holes, explosion-proof valves, and clearance notches. Each explosion-proof valve covers one explosion-proof hole, and the projection of each explosion-proof hole on the electrode assembly is located within one clearance notch and is spaced apart from the edge of the clearance notch.

8. The energy storage device according to any one of claims 1 to 6, characterized in that, The plurality of electrodes also include a plurality of edge electrodes, wherein along the thickness direction of the energy storage device, a portion of the edge electrodes are located on one side of the plurality of central electrodes, and another portion of the edge electrodes are located on the other side of the plurality of central electrodes.

9. The energy storage device according to any one of claims 1 to 6, characterized in that, The plurality of electrodes include a plurality of anode electrodes and a plurality of cathode electrodes, which are arranged in an alternating stacked manner. The projection of each cathode electrode on the anode electrode is located within the anode electrode and is spaced apart from the peripheral side surface of the anode electrode.

10. The energy storage device according to any one of claims 1 to 6, characterized in that, The electrode assembly further includes a first electrode tab and a second electrode tab. Along the length of the energy storage device, the first electrode tab and the second electrode tab are located on opposite sides of the clearance notch, and are spaced apart from the clearance notch, and are electrically connected to the end cap assembly.

11. An electrical appliance, characterized in that, The device includes an energy storage device as described in any one of claims 1 to 10, wherein the energy storage device is used to supply power to the electrical equipment.

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