Energy storage devices and power supply systems

Abstract

This application discloses an energy storage device and a power supply system. The energy storage device includes an end cap assembly, an electrode assembly, and a support member. The electrode assembly includes two electrode units, each including an electrode body and a tab extending from one end of the electrode body. The tabs with the same polarity in the electrode assembly form a tab group, and the tab group surrounds a receiving cavity for accommodating the support member. The tab includes a first connecting portion electrically connected to the electrode body, a second connecting portion electrically connected to the pole unit of the end cap assembly, and a bent portion connecting the first and second connecting portions. The support member includes a main body and a plurality of supporting portions connected to the main body. The plurality of supporting portions are arranged along the Y-axis direction, and a first exhaust channel is formed between adjacent supporting portions. The first connecting portions of the tab group abut against the main body, the second connecting portions of the tab group abut against at least one supporting portion of the support member, and the bent portions of the tab group are located on both sides of the support member along the Y-axis direction.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and more specifically, to an energy storage device and a power supply system. Background Technology

[0002] In recent years, with the rapid development of new energy vehicles, energy storage systems, and consumer electronics, lithium-ion batteries have been widely used due to their advantages such as high energy density and long cycle life. However, batteries may experience adverse reactions under overcharging, short circuits, mechanical abuse, or high-temperature environments, leading to the generation of a large amount of gas inside the battery. The rapid accumulation of this gas can cause a sharp increase in internal pressure, which, if not released in time, may cause the battery casing to rupture or even explode, seriously threatening user safety. Utility Model Content

[0003] This application provides an energy storage device and a power supply system to solve the problem of thermal runaway gas not being released in a timely manner in related technologies.

[0004] The energy storage device according to this application embodiment includes an end cap assembly, an electrode assembly, and a support member; the end cap assembly includes an electrode post unit, the electrode assembly includes two electrode units, each electrode unit includes an electrode body and two tabs extending from one end of the electrode body, and the two tabs with the same polarity in the two electrode units constitute a tab group; each tab includes a first connecting portion electrically connected to the electrode body, a second connecting portion electrically connected to the electrode post unit, and a bent portion connecting the first connecting portion and the second connecting portion; Two electrodes in the electrode assembly form a receiving cavity, and the receiving cavity is provided with a support member. The support member includes a main body and a plurality of support portions connected to the main body. The plurality of support portions are arranged at intervals along the Y-axis direction, and in the Z-axis direction, the plurality of support portions protrude from the main body and extend toward the end cap assembly. A first exhaust channel is formed between adjacent support portions. The Y-axis direction is the width direction of the end cap assembly, and the Z-axis direction is the thickness direction of the end cap assembly. The first connecting portions of the two electrodes in the electrode assembly abut against the corresponding main body, and the second connecting portions of the two electrodes in the electrode assembly abut against at least one support portion of the corresponding support member. The bent portions of the two electrodes in the electrode assembly are located on both sides of the support member along the Y-axis direction.

[0005] According to some embodiments of this application, the second connecting portion is connected to the support member via a first adhesive member.

[0006] According to some embodiments of this application, the support member and the pole post unit have an overlapping area on a projection plane, and the projection plane is perpendicular to the thickness direction of the end cap assembly.

[0007] According to some embodiments of this application, the dimension of the end of the support portion connected to the main body portion along the Y-axis direction is T1, and the dimension of the end of the support portion away from the main body portion along the Y-axis direction is T2, where T1 and T2 satisfy: T1≥T2.

[0008] According to some embodiments of this application, the electrode assembly has a dimension of W along the Y-axis direction, and the support member has a dimension of W1 along the Y-axis direction, where W and W1 satisfy: 0.5W≤W1≤0.9W.

[0009] According to some embodiments of this application, the dimension of the support member along the Y-axis is W1, the number of the support portions is at least three, the distance between adjacent support portions is W2, and W1 and W2 satisfy: 0.2W1≤W2≤0.7W1.

[0010] According to some embodiments of this application, the main body includes a base and an extension. The base is connected to the extension at both ends along the Y-axis. The extension bends and extends from the base toward the end cap assembly, and after bending, the extension forms an arcuate bottom groove for accommodating a portion of the first connecting portion.

[0011] According to some embodiments of this application, the main body is a flat plate structure, and the protrusion heights of the plurality of support portions are equal.

[0012] According to some embodiments of this application, there is a gap between the second connecting portions of the two electrodes in the electrode assembly; One of the support portions of the support member passes through the gap and abuts against the pole unit; or, one of the support portions of the support member passes through the gap and is connected to the pole unit by a second adhesive.

[0013] According to some embodiments of this application, the support member is made of an insulating material, and the melting point of the insulating material is greater than or equal to 200°C.

[0014] According to some embodiments of this application, in the two tabs of the electrode unit, one tab is a positive tab and the other tab is a negative tab. The support member corresponding to the positive tab is made of a first material, and the positive electrode sheet of the electrode body is made of a second material. The first material and the second material are the same. An insulating layer is provided between the negative tab and the corresponding support member.

[0015] According to some embodiments of this application, a second exhaust channel is formed between the curved portion and the support member.

[0016] The power supply system of this application embodiment includes electrical equipment and the energy storage device described in any of the above claims, wherein the energy storage device supplies power to the electrical equipment. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0018] Figure 1 This is a schematic diagram of an energy storage system.

[0019] Figure 2 This is a three-dimensional schematic diagram of a single battery cell.

[0020] Figure 3 yes Figure 2 A schematic diagram of its breakdown.

[0021] Figure 4 It is along Figure 2 A cross-sectional view along section AA, where the outer shell is omitted.

[0022] Figure 5 yes Figure 4 A magnified view of the area at point X1.

[0023] Figure 6 yes Figure 3 A schematic diagram of the support components.

[0024] Figure 7 It is along Figure 2 A cross-sectional view of another embodiment of the AA section line.

[0025] Figure 8 yes Figure 7 A magnified view of the area at X2 in the middle.

[0026] Figure 9 yes Figure 7 A three-dimensional schematic diagram of the supporting components.

[0027] Figure 10 This is a schematic diagram of a power supply system.

[0028] The reference numerals in the attached figures are explained as follows: 100. End cap assembly; 110. Pole post unit; 120. End plate; 130. Explosion-proof valve; 140. Injection port; 200, Electrode assembly; 200a, Electrode unit; 200b, Gap; 210, Electrode body; 211, Battery cell; 220, Tab; 220a, Tab assembly; 220b, Receiving cavity; 221, First connecting part; 222, Second connecting part; 223, Bending part; 224, Inner electrode; 225, Middle electrode; 300, Support component; 310, Main body; 311, Base; 312, Extension; 313, Arc-shaped bottom groove; 320, Support component; 330, First exhaust channel; 340, Second exhaust channel; 400. Outer shell; 410. Receiving cavity; 411. Opening. Detailed Implementation

[0029] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0030] It is understood that the terms "comprising" and "having," and any variations thereof, in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or components inherent to these processes, methods, products, or devices.

[0031] For ease of explanation, the terms "X-axis direction," "Y-axis direction," and "Z-axis direction" are used in the specific embodiments of this application. These terms simply refer to a feature having one of these directions being perpendicular to a feature having another direction; they do not require implementation according to the "X-axis direction," "Y-axis direction," and "Z-axis direction" described in the embodiments. In the embodiments, the X-axis direction, Y-axis direction, and Z-axis direction are mutually perpendicular.

[0032] Unless otherwise specified, in the claims and description, the terms “top,” “bottom,” “inner,” “outer,” “upper,” “lower,” “front,” “rear,” “left,” “right,” etc., indicate the orientation or positional relationship based on the orientation and positional relationship shown in the drawings, and are only for the purpose of simplifying the description, and do not imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation.

[0033] Because the energy people need is highly time- and space-dependent, in order to make rational use of energy and improve energy efficiency, it is necessary to use a medium or device to store one form of energy in the same way or by converting it into another form of energy, and then release it in a specific form of energy based on future application needs.

[0034] 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.

[0035] 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.

[0036] 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: (1) Large-scale energy storage power stations applied to wind power and photovoltaic power stations can help renewable energy power generation meet grid connection requirements and improve the utilization rate of renewable energy. As a high-quality active / reactive power regulation power source on the power supply side, energy storage power stations can achieve load matching of power in time and space, enhance the absorption capacity of renewable energy, reduce instantaneous power changes, reduce the impact on the power grid, improve the absorption of new energy power generation, and are of great significance in power grid system backup, alleviating peak load power supply pressure and peak regulation and frequency regulation. (2) Energy storage containers applied on the grid side mainly function as peak shaving, frequency regulation and relief of grid congestion. In terms of peak shaving, they can realize 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. (3) Small energy storage cabinets applied to the electricity consumption side mainly function as self-consumption of electricity, peak-valley price arbitrage, capacity cost management, and improvement of power supply reliability. Depending on the application scenario, electricity consumption side energy storage can be divided into industrial and commercial energy storage cabinets, household energy storage devices, energy storage charging piles, etc., which are generally used in conjunction with distributed photovoltaics. Industrial and commercial users can use energy storage for peak-valley price arbitrage and capacity cost management. In the electricity market implementing peak-valley pricing, by charging the energy storage system when the electricity price is low and discharging the energy storage system when the electricity price is high, peak-valley price arbitrage can be achieved, reducing electricity costs. In addition, industrial enterprises subject to two-part tariffs can use energy storage systems to store energy during off-peak hours and discharge during peak loads, thereby reducing peak power and the maximum demand declared, achieving the goal of reducing capacity costs. Household photovoltaics with energy storage can improve the level of self-consumption of electricity. Due to high electricity prices and poor power supply stability, the demand for household photovoltaic installations is driven. 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.

[0037] In some embodiments, see Figure 1 , Figure 1 This is a schematic diagram of the structure of an energy storage system according to an embodiment of this application, and Figure 1 Taking the shared energy storage scenario on the power generation / distribution side as an example, the energy storage device in this application is not limited to the power generation / distribution side energy storage scenario.

[0038] This application provides an energy storage system, comprising: a high-voltage cable 2, a first power conversion device 3, a second power conversion device 4, and the energy storage device 1 provided in this application. 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 1 through grid connection. The energy storage device 1 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 ensuring 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 1 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 1 in conjunction with high-voltage cable 2 in grid-connected mode 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 on the power grid.

[0039] 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 1 is connected to the high-voltage cable 2 and installed downstream of the high-voltage cable 2 between the user load and the high-voltage cable 2. The power output of the photovoltaic power conversion device is stored in the energy storage device 1, which can respond in time to act as a backup power source when the power grid / distribution network fails. Alternatively, it can provide power supply support to alleviate line blockage 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.

[0040] Optionally, the first power conversion device 3 may include, but is not limited to, a wind power conversion device, and the second power conversion device 4 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.

[0041] Optionally, the energy storage device 1 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.

[0042] Optionally, the energy storage device 1 can be, but is not limited to, a single battery (secondary battery), a battery module composed of single batteries, a battery pack, an energy storage cabinet, an energy storage container, etc. The actual application form of the energy storage device 1 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 1.

[0043] The individual battery cells 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. Individual battery cells can be cylindrical, flat, cuboid, etc., and this application does not limit the specific form. The following description uses a cuboid individual battery cell as an example for energy storage device 1.

[0044] First Embodiment

[0045] like Figure 2 and Figure 3 As shown, the energy storage device 1 includes a housing 400, an end cap assembly 100, and an electrode assembly 200. The housing 400 includes a receiving cavity 410 with an opening 411. The electrode assembly 200 can be installed in the receiving cavity 410 through the opening 411. The end cap assembly 100 covers the opening 411 of the housing 400 to enclose the electrode assembly 200 inside the housing 400.

[0046] In one exemplary embodiment, the outer casing 400 is a rectangular parallelepiped. Optionally, the outer casing 400 can be a steel casing, an aluminum casing, a plastic casing (such as polypropylene), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc.

[0047] The end cap assembly 100 includes an end plate 120 and two pole post units 110. The end plate 120 covers the opening 411 of the outer shell 400, and the pole post units 110 are fixed on the end plate 120. The two pole post units 110 can be arranged along the length direction of the end plate 120, and one pole post unit 110 has a positive polarity and the other pole post unit 110 has a negative polarity.

[0048] In one embodiment, the end plate 120 is a rectangular plate structure. The X-axis direction is the length direction of the end plate 120, the Y-axis direction is the width direction of the end plate 120, and the Z-axis direction is the thickness direction of the end plate 120.

[0049] Each electrode unit 110 may include an electrode post, an upper plastic layer, and an adapter. The upper plastic layer surrounds the electrode post to electrically insulate the electrode post from the end plate 120. The electrode assembly 200 is electrically connected to the electrode post via the adapter.

[0050] In one embodiment, the end plate 120 can be connected to the housing 400 by welding or rolling to cover the opening 411 of the housing 400.

[0051] like Figure 2 and Figure 3 As shown, the end cap assembly 100 also includes an explosion-proof valve 130, which is disposed on the end plate 120 and is used to burst when the gas pressure inside the housing 400 reaches a threshold to discharge the gas inside the housing 400, thereby preventing the housing 400 from bulging or even exploding.

[0052] The end plate 120 is also provided with a liquid injection hole 140, which penetrates the end plate 120 along the Z-axis. Electrolyte can be injected into the housing 400 through the liquid injection hole 140.

[0053] like Figure 3 As shown, the electrode assembly 200 includes two electrode units 200a. Each electrode unit 200a includes an electrode body 210 and two tabs 220 extending from one end of the electrode body 210. The two tabs 220 with the same polarity in the two electrode units 200a constitute a tab group 220a. The tabs 220 are electrically connected to the electrode post unit 110.

[0054] In an exemplary embodiment, two electrode units 200a are stacked along the Y-axis direction, one set of tabs 220a in the electrode assembly 200 is electrically connected to the positive polarity pole unit 110, and the other set of tabs 220a in the electrode assembly 200 is electrically connected to the negative polarity pole unit 110.

[0055] In one embodiment, each electrode body 210 includes at least one battery cell 211, which may be wound or stacked, and this application does not make any particular limitation on this.

[0056] In an exemplary embodiment, each electrode body 210 includes two stacked battery cells 211, and one end of each of the two battery cells 211 of each electrode body 210 is provided with two tabs 220.

[0057] The battery cell 211 includes a positive electrode, a negative electrode, and a separator. A single battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, and the uncoated positive current collector protrudes beyond the coated one, serving as the positive electrode tab. Taking a lithium-ion battery as an example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector, and the uncoated negative current collector protrudes beyond the coated one, serving as the negative electrode tab. The negative current collector can be made of copper, and the negative active material can be carbon or silicon, etc. The material of the separator can be PP or PE, etc.

[0058] The inventors of this application discovered in their research that when a battery experiences thermal runaway, the gas generated by the electrode assembly 200 flows towards the explosion-proof valve 130. Since the explosion-proof valve 130 is located on the end plate 120, the gas flow causes the electrode assembly 200 to move upwards, thereby squeezing the tab 220 and causing it to deform under pressure. After the tab 220 is deformed under pressure, the distance between the electrode assembly 200 and the terminal unit 110 decreases sharply, which in turn causes the airflow channel along the X-axis of the battery to be blocked by the electrode assembly 200. This further obstructs the smooth flow of gas from both sides of the electrode assembly 200 along the X-axis towards the explosion-proof valve 130, making the outer casing 400 prone to cracking or even explosion.

[0059] Based on this, such as Figures 3 to 5As shown, the tab 220 includes a first connecting portion 221 electrically connected to the electrode body 210, a second connecting portion 222 electrically connected to the electrode post unit 110, and a bent portion 223 connecting the first connecting portion 221 and the second connecting portion 222. The energy storage device 1 also includes a support member 300. Two tabs 220 in the tab assembly 220a form a receiving cavity 220b, and the support member 300 is provided inside the receiving cavity 220b. The support member 300 includes a main body 310 and a plurality of support portions 320 connected to the main body 310. The plurality of support portions 320 are arranged at intervals along the Y-axis direction, and in the Z-axis direction, the plurality of support portions 320 protrude from the main body 310 and extend toward the end cap assembly 100. A first exhaust channel 330 is formed between adjacent support portions 320. The first connecting portions 221 of the two tabs 220a in the tab group 220a abut against the main body 310 of the corresponding support member 300, and the second connecting portions 222 of the two tabs 220a in the tab group 220a abut against at least one support portion 320 of the corresponding support member 300. The bent portions 223 of the two tabs 220a in the tab group 220a are located on both sides of the support member 300 along the Y-axis direction.

[0060] In this embodiment, a support member 300 is provided in the receiving cavity 220b formed by the two tabs 220 in the tab assembly 220a, and the adjacent support portions 320 in the support member 300 form a first exhaust channel 330. This ensures that the support member 300 has sufficient spacing between the first connecting portion 221 and the second connecting portion 222, preventing the tabs 220 from being excessively squeezed due to the thermal runaway gas driving the electrode assembly 200 to float. This also prevents the airflow channel for gas flow from being blocked due to the deformation of the tabs 220 under pressure. This ensures that the gas generated by the electrode assembly 200 can flow smoothly through the first exhaust channel 330 along the X-axis direction, so that the gas can be released in time, preventing the energy storage device 1 from bulging or even exploding, thus improving safety.

[0061] It should also be noted that in related technologies, to prevent the tab 220 from breaking when the two electrode units 200a of the electrode assembly 200 are joined, the length of the tab 220 is redundantly designed. However, due to this redundant design, the tab 220 may bend randomly when the two electrode units 200a of the electrode assembly 200 are joined, forming an S-shape. This bending of the tab 220 increases the distance between the positive and negative electrodes, resulting in a longer ion channel, increased impedance, and reduced energy efficiency. Furthermore, if the tab 220 bends significantly, it may insert into the electrode body 210, causing a short circuit in the electrode assembly 200.

[0062] Therefore, in this embodiment, the support member 300 is supported between the first connecting part 221 and the second connecting part 222. The support member 300 plays a shaping role for the tab 220 to a certain extent. When the two electrode units 200a of the electrode assembly 200 are closed, the tab 220 can bend and form a fixed shape without disorderly bending. This avoids the distance between the positive and negative electrode plates in the electrode body 210 being increased due to the S-shaped bending of the tab 220, and also avoids the problem of short circuit in the electrode assembly 200 caused by the tab 220 being inserted into the electrode body 210. This improves the structural performance and safety performance of the energy storage device 1.

[0063] It should be noted that the term "butt" refers to two parts coming into contact and having an interaction force between them. This contact can be direct or indirect.

[0064] like Figure 5 In one embodiment, a plurality of support portions 320 protrude from the side surface of the main body portion 310 facing the end cap assembly 100.

[0065] In an exemplary embodiment, the energy storage device 1 includes two support members 300, which correspond to the positive electrode tab and the negative electrode tab, respectively. That is, one support member 300 is supported between the first connecting portion 221 and the second connecting portion 222 of the positive electrode tab, and the other support member 300 is supported between the first connecting portion 221 and the second connecting portion 222 of the negative electrode tab.

[0066] In one embodiment, the corresponding support member 300 and the pole post unit 110 have an overlapping area on a projection plane, and the projection plane is perpendicular to the thickness direction (Z-axis direction) of the end cap assembly 100.

[0067] In this embodiment, in the Z-axis direction, the corresponding support member 300 and the pole post unit 110 have an overlapping area on the projection plane. When the support member 300 abuts against the second connecting part 222, the pole post unit 110 can also abut against the support member 300. When the electrode body 210 generates thermal runaway gas, since the pole post unit 110 abuts against the support member 300, the support member 300 can stably abut against the first connecting part 221, thereby preventing the electrode body 210 from floating up and blocking the airflow channel, and ensuring that the thermal runaway gas can flow smoothly along the X-axis direction.

[0068] In one embodiment, the second connecting portion 222 is connected to the support member 300 via a first adhesive member.

[0069] In this embodiment, before the two electrode units 200a of the electrode assembly 200 are closed, the support member 300 and the second connecting part 222 can be connected by the first adhesive member, so that the support member 300 is centered in the Y-axis direction relative to the second connecting part 222 of the two tabs 220 of the same polarity, so as to prevent the support member 300 from shifting in the Y-axis direction when the two electrode units 200a of the electrode assembly 200 are closed, so that it moves closer to the bending part 223 of one of the tabs 220 and away from the bending part 223 of the other tab 220.

[0070] Conversely, if the position of the support 300 is offset (i.e., the support 300 is close to the bend 223 of one of the tabs 220 and far away from the bend 223 of the other tab 220), when the two electrode units 200a of the electrode assembly 200 are closed, the tab 220 close to the support 300 is easily pushed by the support 300 and breaks, while the tab 220 far away from the support 300 is easily twisted due to redundant design and not shaped by the support 300. The twisted tab 220 has a greater risk of being inserted into the electrode body 210, which can easily cause a short circuit in the electrode assembly 200.

[0071] Optionally, the first adhesive component can be double-sided tape or blue adhesive.

[0072] like Figure 5 As shown, there is a gap 200b between the second connecting portions 222 of the two tabs 220 in the tab assembly 220a. One of the support portions 320 of the support member 300 passes through the gap 200b and abuts against the pole post unit 110; or, one of the support portions 320 of the support member 300 passes through the gap 200b and is connected to the pole post unit 110 by a second adhesive.

[0073] In this embodiment, when one of the support portions 320 of the support member 300 passes through the gap 200b and abuts against the pole unit 110, the pole unit 110 can directly abut against the support member 300. When the electrode body 210 generates thermal runaway gas, since the pole unit 110 directly abuts against the support member 300, the support member 300 can stably abut against the first connecting portion 221, thereby preventing the electrode body 210 from floating up and blocking the airflow channel, and ensuring that the thermal runaway gas can flow smoothly along the X-axis direction.

[0074] When one of the support portions 320 of the support member 300 passes through the gap 200b and is connected to the pole unit 110 by the second adhesive, the second connecting portion 222 of the support member 300 relative to the two pole ears 220 of the same polarity in the Y-axis direction can be centered, so as to prevent the support member 300 from shifting in the Y-axis direction when the electrode assembly 200 is closed, and thus approaching the bending portion 223 of one pole ear 220 and moving away from the bending portion 223 of the other pole ear 220.

[0075] Optionally, when one of the support portions 320 of the support member 300 passes through the gap 200b and is connected to the pole unit 110 by a second adhesive, the second adhesive can be double-sided adhesive or hot melt adhesive.

[0076] In another embodiment, the second connecting portions 222 of the two electrodes 220 in the electrode assembly 220a may not have a gap 200b, but rather the second connecting portions 222 of the two electrodes 220 are stacked on top of each other.

[0077] like Figure 5 As shown, a second exhaust channel 340 is formed between the curved portion 223 and the support member 300.

[0078] In this embodiment, based on the first exhaust channel 330, a second exhaust channel 340 is also formed between the bent portion 223 and the support member 300. The second exhaust channel 340 increases the flow area of ​​the airflow channel. The thermal runaway gas can flow through the first exhaust channel 330 and the second exhaust channel 340 simultaneously in the X-axis direction. Under the combined action of the first exhaust channel 330 and the second exhaust channel 340, the gas release speed is accelerated.

[0079] like Figure 5 and Figure 6 As shown, the main body 310 includes a base 311 and an extension 312. The base 311 is connected to the extension 312 at both ends along the Y-axis. The extension 312 bends and extends from the base 311 toward the end cap assembly 100, and after bending, the extension 312 forms an arcuate bottom groove 313 for accommodating part of the first connecting part 221.

[0080] In related technologies, the tab 220 typically includes multiple stacked electrode sheets, which bend simultaneously when the electrode assembly 200 is closed. To prevent each electrode sheet from breaking during bending, the redundancy of the inner electrode sheet (hereinafter referred to as inner electrode sheet 224) is greater than that of the middle electrode sheet (hereinafter referred to as middle electrode sheet 225). However, when the redundancy of the inner electrode sheet 224 is too large, bending it will compress the middle electrode sheet 225. If this redundancy exceeds the redundancy of the middle electrode sheet 225, the middle electrode sheet 225 is prone to breakage. In this embodiment, an arc-shaped bottom groove 313 is provided on the main body 310. The arc-shaped bottom groove 313 provides clearance space for the inner electrode 224. In this way, when the electrode assembly 200 is closed, the inner electrode 224 will bend into the arc-shaped bottom groove 313 without excessively squeezing the middle electrode 225, thus avoiding the middle electrode 225 from breaking due to the squeezing of the inner electrode 224.

[0081] A support portion 320 is provided on the base 311 and / or the extension 312. In one embodiment, the support portion 320 is provided at the end of the extension 312 away from the base 311.

[0082] like Figure 6 As shown, the dimension of the end of the support portion 320 connected to the main body portion 310 along the Y-axis is T1, and the dimension of the end of the support portion 320 away from the main body portion 310 along the Y-axis is T2. T1 and T2 satisfy: T1≥T2.

[0083] In this embodiment, T1≥T2, which improves the connection strength between the support part 320 and the main body part 310, thereby enhancing the bending resistance of the support part 320 and ensuring the stability of the support member 300.

[0084] like Figure 5 and Figure 6 As shown, the electrode assembly 200 has a dimension of W along the Y-axis, and the support member 300 has a dimension of W1 along the Y-axis. W and W1 satisfy: 0.5W≤W1≤0.9W.

[0085] In this embodiment, W and W1 satisfy: 0.5W≤W1≤0.9W, which can both ensure that the support member 300 can straighten and shape the bent shape of the tab 220, and avoid the support member 300 from excessively squeezing the tab 220 and causing the tab 220 to break.

[0086] Conversely, if W1 < 0.5W, it indicates that the size of the support member 300 along the Y-axis is small, and the support member 300 is insufficient in straightening and shaping the tab 220, which may easily cause the tab 220 to twist and be inserted into the electrode body 210; if W1 > 0.9W, it indicates that the size of the support member 300 along the Y-axis is large, and when the electrode assembly 200 is closed, the support member 300 will excessively compress the tab 220, resulting in insufficient redundancy of the tab 220 and breakage.

[0087] like Figure 6 As shown, the number of support parts 320 is at least three, and the distance between adjacent support parts 320 is W2. W1 and W2 satisfy: 0.2W1≤W2≤0.7W1.

[0088] In this embodiment, W1 and W2 satisfy: 0.2W1≤W2≤0.7W1. On the one hand, this ensures the structural strength of the support 300 and prevents the support 300 from being flattened by the electrode assembly 200. On the other hand, it avoids the adjacent support portions 320 being too close together, which would result in insufficient cross-sectional area of ​​the gas flow channel and improves the smoothness of gas passing through the support 300 along the X-axis.

[0089] Conversely, if W2 < 0.2W1, it indicates that the spacing between adjacent support parts 320 is too close, resulting in insufficient cross-sectional area of ​​the gas flow channel and obstructed gas flow. If W2 > 0.7W1, it indicates that the spacing between adjacent support parts 320 is large, indicating that the support parts 320 arranged on one side surface of the support part 320 are sparse, resulting in insufficient overall structural strength of the support member 300. When thermal runaway occurs, the electrode assembly 200 may float up and flatten the support member 300, causing the gas flow channel to be blocked.

[0090] It should be noted that multiple W2 values ​​can be equal or unequal. Figure 6 Taking the support member 300 shown as an example, the W2 located in the middle region is smaller than the W2 located on both sides.

[0091] In one embodiment, the support 300 is made of an insulating material with a melting point greater than or equal to 200°C.

[0092] In this embodiment, the support member 300 is made of an insulating material with a melting point greater than or equal to 200°C, which can prevent the high-temperature gas generated by thermal runaway from melting the support member 300, thereby preventing the support member 300 from losing its supporting function.

[0093] As an example, the support 300 can be made of ceramic material.

[0094] It should be noted that the support member 300 is not limited to being made of insulating material; it can also be made of conductive material, but an insulating layer must be provided between the negative electrode tab and the corresponding support member 300. Specifically: The support member 300 corresponding to the positive electrode tab is made of a first material, and the positive electrode sheet of the electrode body 210 is made of a second material. The first material and the second material are the same. An insulating layer is provided between the negative electrode tab and the corresponding support member 300.

[0095] Since the support member 300 corresponding to the positive electrode tab and the positive electrode sheet of the electrode body 210 are made of the same material, no oxidation-reduction reaction will occur between the support member 300 and the positive electrode sheet. Therefore, no insulation treatment is required between the support member 300 and the positive electrode tab. However, an insulating layer needs to be provided between the negative electrode tab and the corresponding support member 300 to prevent oxidation-reduction reaction. Therefore, in this embodiment, by providing an insulating layer between the negative electrode tab and the corresponding support member 300, the support member 300 can be made of a metal material with a higher melting point and lower cost, saving costs while ensuring that the support member 300 can provide a supporting effect.

[0096] In one exemplary embodiment, both the first material and the second material are aluminum alloys.

[0097] Optionally, the insulating layer can be an adhesive layer bonded to the surface of the support 300; or, the insulating layer can be formed on the surface of the support 300 by means of coating, electrophoresis, spraying, etc.

[0098] Second Embodiment

[0099] The similarities between the energy storage device 1 in the second embodiment and the energy storage device 1 in the first embodiment will not be repeated here. The differences are as follows: like Figures 7 to 9 As shown, the support member 300 includes a main body 310 and a plurality of support parts 320. The main body 310 has a flat plate structure, and the plurality of support parts 320 protrude from the side surface of the main body 310 facing the end cap assembly 100, and the protrusion height of the plurality of support parts 320 is equal.

[0100] The distance between any two adjacent support parts 320 is W2, and multiple W2s can be equal or unequal.

[0101] like Figure 10 As shown, this application also provides a power supply system 6, including an electrical device 5 and an energy storage device 1 of any of the above, wherein the energy storage device 1 supplies power to the electrical device 5.

[0102] It is understood that the various embodiments / implementations provided in this application can be combined with each other without creating contradictions, and will not be described one by one here.

[0103] In the embodiments of this application, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise expressly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0104] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the claims. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0105] The above are merely preferred embodiments of the application examples and are not intended to limit the application examples. For those skilled in the art, the application examples can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the application examples should be included within the protection scope of the application examples.

Claims

1. An energy storage device, characterized in that, The device includes an end cap assembly, an electrode assembly, and a support member. The end cap assembly includes a pole post unit, and the electrode assembly includes two electrode units. Each electrode unit includes an electrode body and two tabs extending from one end of the electrode body. Two tabs with the same polarity in the two electrode units constitute a tab group. Each tab includes a first connecting portion electrically connected to the electrode body, a second connecting portion electrically connected to the pole post unit, and a bent portion connecting the first connecting portion and the second connecting portion. Two electrodes in the electrode assembly form a receiving cavity, and a support member is provided inside the receiving cavity. The support member includes a main body and a plurality of support portions connected to the main body. The plurality of support portions are arranged at intervals along the Y-axis direction, and in the Z-axis direction, the plurality of support portions protrude from the main body and extend toward the end cap assembly. A first exhaust channel is formed between adjacent support portions. The Y-axis direction is the width direction of the end cap assembly, and the Z-axis direction is the thickness direction of the end cap assembly. The first connecting portions of the two electrodes in the electrode assembly abut against the corresponding main body, and the second connecting portions of the two electrodes in the electrode assembly abut against at least one support portion of the corresponding support member. The bent portions of the two electrodes in the electrode assembly are located on both sides of the support member along the Y-axis direction.

2. The energy storage device according to claim 1, characterized in that, The second connecting part is connected to the support member by the first adhesive.

3. The energy storage device according to claim 1, characterized in that, The support member and the pole post unit have an overlapping area on a projection plane, and the projection plane is perpendicular to the thickness direction of the end cap assembly.

4. The energy storage device according to claim 1, characterized in that, The dimension of the end of the support portion connected to the main body portion along the Y-axis is T1, and the dimension of the end of the support portion away from the main body portion along the Y-axis is T2. T1 and T2 satisfy: T1≥T2.

5. The energy storage device according to claim 1, characterized in that, The electrode assembly has a dimension of W along the Y-axis, and the support has a dimension of W1 along the Y-axis. W and W1 satisfy: 0.5W ≤ W1 ≤ 0.9W.

6. The energy storage device according to claim 1, characterized in that, The dimension of the support member along the Y-axis is W1, the number of the support parts is at least three, the distance between adjacent support parts is W2, and W1 and W2 satisfy: 0.2W1≤W2≤0.7W1.

7. The energy storage device according to claim 1, characterized in that, The main body includes a base and an extension. The base is connected to the extension at both ends along the Y-axis. The extension bends and extends from the base toward the end cap assembly, and after bending, the extension forms an arc-shaped bottom groove for accommodating part of the first connecting portion.

8. The energy storage device according to claim 1, characterized in that, The main body is a flat plate structure, and the protrusion height of the multiple supporting parts is equal.

9. The energy storage device according to claim 1, characterized in that, There is a gap between the second connecting portions of the two electrodes in the electrode assembly; One of the support portions of the support member passes through the gap and abuts against the pole unit; or, one of the support portions of the support member passes through the gap and is connected to the pole unit by a second adhesive.

10. The energy storage device according to claim 1, characterized in that, The support is made of an insulating material, and the melting point of the insulating material is greater than or equal to 200°C.

11. The energy storage device according to claim 1, characterized in that, In the two tabs of the electrode unit, one tab is a positive tab and the other tab is a negative tab. The support member corresponding to the positive tab is made of a first material, and the positive electrode sheet of the electrode body is made of a second material. The first material and the second material are the same. An insulating layer is provided between the negative tab and the corresponding support member.

12. The energy storage device according to claim 1, characterized in that, A second exhaust channel is formed between the curved portion and the support member.

13. A power supply system, characterized in that, It includes electrical equipment and the energy storage device according to any one of claims 1-12, wherein the energy storage device supplies power to the electrical equipment.

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