Current collector for energy storage units, supercapacitor equipped with the current collector, and energy storage module for data centers

Abstract

The present invention relates to a current collector for an energy storage unit, a supercapacitor equipped with the current collector, and an energy storage module for a data center. In order to achieve a lower ESR and improved thermal characteristics, the present invention proposes a current collector assembly (10) for a cylindrical supercapacitor (50), the current collector assembly (10) comprising: a cylindrical electrode assembly (12) having an axial contact surface (14); and a current collector (30) having a current tab portion (32) and a blade portion (40), wherein the current tab portion (32) has a straight long side (34) and a short side (36), wherein the blade portion (40) protrudes from the long side (34), wherein the length of the long side (34) is 0.8 to 1.0 times the diameter of the electrode assembly (12).

Description

Technical Field

[0001] This invention relates to current collector components for supercapacitors. The invention also relates to supercapacitors and energy storage modules. Background Technology

[0002] Applications of energy storage units are becoming increasingly specialized. An emerging application is peak shaving for artificial intelligence (AI) data centers (i.e., data centers running AI models).

[0003] Peak shaving refers to the practice of absorbing very short-lived spikes in electricity demand within a facility, rather than drawing those spikes from the public power grid. AI workloads are a prime example, as racks filled with GPUs can jump from idle to hundreds of kilowatts of power demand within milliseconds, such as during training steps or a batch of concurrent inference calls. Grid providers and data center operators generally dislike this peak load curve because generation and transmission need to be adjusted for instantaneous peaks, even if average consumption is much lower.

[0004] Energy storage units can generally be divided into batteries and capacitors. Batteries store electrical energy in a chemical form, while capacitors typically store electrical energy in the form of an electric field. Capacitors, especially supercapacitors—often used in energy storage modules—can be used to provide the necessary power in a short time, such as milliseconds.

[0005] A supercapacitor, also known as a supercapacitor, is a type of capacitor and can be divided into electric double-layer capacitors and pseudocapacitors. Electric double-layer capacitors store electrical energy in an electrostatic double layer, while pseudocapacitors store electrical energy electrochemically, but in a manner different from that of a battery. Recently, hybrid (super)capacitors have been developed that combine the characteristics of both electric double-layer capacitors and pseudocapacitors.

[0006] CN 222 601 167 U discloses a cover assembly for a battery. The cover assembly includes sequentially stacked electrical connectors, a first insulating member, a cover plate, and a second insulating member. Multiple anti-rotation structures are provided to effectively prevent relative rotation between two adjacent structural members, thereby achieving anti-rotation positioning of each structural member. The cover assembly also includes a current collector, which has a first welding area and a second welding area. A terminal post is welded to the first welding area, and the second welding area is used for welding to the battery core.

[0007] CN 222 581 303 U discloses another example of a current collector.

[0008] CN 222 507 917 U discloses a current collector and a battery, and aims to improve the technical problem of obstructed electrolyte flow path after current collector and electrode welding. The current collector includes a body portion having a central through hole and edge openings and a group of peripheral through holes located on opposite sides of the central through hole. The group of peripheral through holes includes at least one peripheral through hole, and the depth direction of the edge openings faces the central through hole.

[0009] CN 119 650 810 A discloses a positive electrode current collector, which includes a disk body and a tail body connected to a flat structure of the positive electrode, the tail body being connected to a cap.

[0010] CN 115 298 896 A discloses a secondary battery in which the positive electrode is connected to a positive current collector at one end of an electrode winding body, and the negative electrode is on the electrode winding body. The other end of the winding body is connected to a negative current collector. The thickness of the uncovered portion of the material is 5 µm or more and 20 µm or less, the thickness of the uncovered portion of the negative electrode active material is 6 µm or more and 20 µm or less, the number of overlapping sheets of the uncovered portion of the positive electrode active material on the positive electrode side is 2 or more, and the number of overlapping sheets of the uncovered portion of the negative electrode active material on the negative electrode side is 2 or more.

[0011] CN 114 975 846 A discloses another example of a current collector.

[0012] EP 3 996 195 A1, EP 2 207 233 B1, US 2024 / 0 055 727 A1, US 2023 / 0395 956 A1, US 2013 / 0 252 054 A1, US 2010 / 0 104 945 A1, US 2007 / 0 298 317 A1 and US 2007 / 0 269 685 A1 disclose other examples of current tabs. Summary of the Invention

[0013] The purpose of this invention is to improve energy storage units, preferably supercapacitors.

[0014] This objective is achieved through the subject matter of the main aspects of the invention. Preferred embodiments are the subject matter of other aspects of the invention.

[0015] The present invention provides a current collector assembly for a cylindrical supercapacitor, the current collector assembly comprising: a cylindrical electrode assembly having an axial contact surface; and a current collector having a current contact portion and a blade portion, wherein the current contact portion has a straight long side and a short side, wherein the blade portion protrudes from the long side, and wherein the length of the long side is 0.8 to 1.0 times the diameter of the electrode assembly.

[0016] Preferably, the ratio of the length of the shorter side to the length of the longer side is 1:2 to 1:3.

[0017] Preferably, the width of the blade portion is 50% to 80% of the length of the long side, preferably 60% to 72%, preferably 63% to 69%, and preferably 2 / 3.

[0018] Preferably, the blade portion has a wider cross-section and / or has an extension structure toward the current contact portion.

[0019] Preferably, the extension structure is located close to the welding line, making the extension structure suitable for providing a shorter path for current travel from the electrode assembly to the negative current contact.

[0020] Preferably, the shape of the short side is selected from any of the following: a straight short side; a straight short side with rounded corners; and a circular short side, preferably an annular short side.

[0021] Preferably, the current contact portion has an alignment feature formed therein, which is configured to enable the current contact portion to be aligned on the contact surface, preferably centered.

[0022] Preferably, the current contact portion is welded to the contact surface, and at least one pair of welds are formed parallel to the long side.

[0023] Preferably, the length of each weld is 25% to 100% of the length of the long side, preferably 25% to 41%, preferably 30% to 36%, and preferably 1 / 3.

[0024] Preferably, the weld is equidistant from an imaginary line indicating the diameter of the marked contact surface. Preferably, the weld is equidistant from the long side. Preferably, the weld is equidistant from an imaginary line that is itself equidistant from the long side.

[0025] Preferably, the distance between parallel welds is such that the area enclosed by the imaginary line connecting the weld to its corresponding nearest endpoint is the same as the area enclosed by each weld in the weld connected to its nearest long side by an imaginary line starting from its endpoint, all of which are parallel.

[0026] Preferably, the current collector assembly further includes a terminal member, wherein the blade portion has a tapered end that is electrically fixed to the terminal member.

[0027] Preferably, the current collector assembly further includes a cover member and an insulating member. Preferably, the terminal member is fixed to the cover member via the insulating member, such that the cover member and the terminal member are electrically insulated from each other.

[0028] Preferably, the blade portion has at least one curved portion that allows adjacent portions of the blade portion to be stacked on top of each other parallel to the contact surface without the adjacent portions contacting each other in a direction perpendicular to the contact surface.

[0029] The present invention provides a cylindrical supercapacitor configured for storing electrical energy, the supercapacitor comprising a cylindrical can and a preferred current collector assembly, wherein an electrode assembly is inserted into the can and electrically connected to the can.

[0030] Preferably, the can is closed by a fixed lid assembly, and the lid assembly is preferably formed of a lid member, an insulating member, and a terminal member.

[0031] Preferably, the can is closed by a lid assembly fixed to the can, preferably welded to the can, and the lid assembly is preferably formed of a lid member, an insulating member, and a terminal member.

[0032] Preferably, the blade portion is bent at least once, such that adjacent portions of the blade portion are stacked on top of each other parallel to the contact surface, without the adjacent portions contacting each other in a direction perpendicular to the contact surface.

[0033] The present invention provides an energy storage module configured to provide electrical power to an electrical system as needed. The energy storage module includes an energy storage unit and a control unit. The energy storage unit includes a plurality of preferred supercapacitors, and the control unit controls the charging and discharging of the energy storage unit.

[0034] Preferably, the control unit is configured to control the energy storage unit to achieve peak shaving of electrical load in the data center (preferably an AI data center).

[0035] In pursuit of ultra-low internal resistance and superior thermal performance for high-power applications, the design of cylindrical supercapacitor cells has been improved. The innovations revolve around new cap connection strips and welded configurations, features that collectively minimize the equivalent series resistance (ESR).

[0036] The structure of the cover connecting strip increases the accumulation of electrons from the electrode to the current contact, which achieves a lower ESR in the cell.

[0037] The lower ESR results in less unit heat generation even during peak-shaving events. This enhances thermal stability under typical AI data center conditions. Furthermore, the effective reduction in unit heat dissipation allows the unit to be used without increasing the data center's cooling capacity. It can also be reduced to the rated power of such a data center's power line, since, at least during peak-shaving events, the required additional power can be obtained from the energy storage module equipped with the unit according to the invention, rather than from the power grid.

[0038] Cylindrical supercapacitors comprise a helical wound electrode assembly containing active material. This electrode assembly is also referred to as the core. The positive electrode can use activated carbon, while the negative electrode can be incorporating activated carbon or (micro)porous carbon. These materials are known for their high surface area and capacitive properties, and have recently undergone several development cycles of improvement, enabling enhanced charge storage capabilities. However, the main advantage of this design lies in the electromechanical interface between the core and the external circuitry.

[0039] The cylindrical unit can have standard components such as positive current contacts, negative current contacts, a cylindrical can housing, gaskets for sealing, and electrolyte filling holes. It integrates specialized cap connecting strips, current collectors, bridging cores, and negative current contacts.

[0040] Unlike conventional designs where current transmission paths are typically indirect, this invention combines a cover connecting strip with a unique geometry and a welding arrangement. The current contact portion may include two sets of parallel straight weld lines, each set positioned opposite each other and preferably equidistant from the central axis of the unit. These weld lines directly connect the core to the cover strip, resulting in uniform current distribution and a strong mechanical bond.

[0041] The proximity of the weld lines, for example, spacing between 1 mm and 7 mm, can significantly enhance current collection from the core. This close spacing allows for a reduction in electrical path length, enabling electrons to reach the cover strip with reduced resistance and increased velocity. Various weld configurations, including radial and distributed patterns, were evaluated during extensive testing. Surprisingly, the parallel layout achieved the lowest ESR.

[0042] The described configuration achieves a shorter and more uniform current path from the electrode assembly to the external terminals. Therefore, ESR can be reduced. Furthermore, localized heating can be mitigated.

[0043] Another idea is to modify the physical dimensions of the current collector. The current collector preferably has an extended structure that spreads out towards the negative current contacts, closely aligned with all solder contact points. This enlarged surface area can serve as both a heat sink and a low-resistance bridge, thereby significantly shortening the path from the core to the external circuitry.

[0044] The current collector's structure reduces resistive losses typically associated with narrower, more isolated connection paths. The wider current collector allows current to flow through multiple parallel paths, effectively reducing the overall ESR of the unit. Empirical data collected from performance testing shows that this structural change contributes to significant improvements in both instantaneous power delivery and heat dissipation. Under thermal loads, the shorter path length and increased conductivity achieve faster thermal equilibrium, improving operational safety and component lifespan.

[0045] Negative current contacts that interface with current collectors typically include a three-legged structure. Each leg is spaced apart, allowing for a unified connection point for current to flow out of the unit. Two legs are usually shorter, while the third leg can have a wider contact surface, further enhancing electrical and thermal stability. This geometry supports efficient current transfer from the current collector, distributes the electrical load evenly across the connection, and reduces hotspot formation.

[0046] The combination of a wide, extended cover strip and an improved weld configuration forms a system-level solution that enables faster current accumulation and transmission. Once current is captured from the core, it propagates along a carefully designed, short, and wide path with minimal resistance. The directness of this connection significantly reduces impedance compared to known designs. Furthermore, the weld distribution characteristics ensure redundancy and stability even under mechanical stress or thermal cycling conditions.

[0047] In addition to performance, this design also improves manufacturability. The repeatability and symmetry of the welding line simplify the automated welding process during production, ensuring consistency in high-volume manufacturing. This helps scale up the production of these units while maintaining stringent quality control.

[0048] The applicant's tests on this unit design achieved the lowest ESR recorded among any commercially available D33 form factor supercapacitor. In high-frequency applications, where millisecond-level issues and internal resistance can determine or destroy efficiency, even small improvements can be decisive.

[0049] Furthermore, the design has a significant impact on thermal management. As current flows more efficiently and directly through an optimized path, the resulting IA 2 R-loss can be further reduced, thereby reducing excessive heat generation. Consequently, the unit can maintain a lower operating temperature, which directly relates to extended lifespan and improved reliability—crucial considerations for mission-critical installations such as server clusters, grid backup systems, and transport power modules.

[0050] Overall, the internal current path of the cell enables a reduction in the distance electrons must travel to increase the conduction area, thereby achieving lower ESR and enhanced thermal performance. Attached Figure Description

[0051] Embodiments of the present invention will be described in more detail with reference to the accompanying drawings listed below:

[0052] Figure 1 An implementation of the current collector assembly is described;

[0053] Figure 2 A perspective view of the current collector is depicted;

[0054] Figure 3 A perspective view depicting a pre-bent current collector; and

[0055] Figure 4 A cross-section through the top of the energy storage unit is depicted. Detailed Implementation

[0056] Reference Figure 1 The diagram illustrates a current collector assembly 10. The current collector assembly 10 includes an electrode assembly 12. The electrode assembly 12 is fabricated in a typical manner and includes active materials for an anode and a cathode disposed on a conductive surface. The electrodes are separated by a diaphragm. The entire electrode assembly 12 is fabricated by winding the electrodes and the diaphragm in a manner known per se. The electrode assembly 12 forms a contact surface 14. The contact surface 14 allows contact with one of the electrodes of the electrode assembly 12.

[0057] The current collector assembly 10 includes a cover assembly 16. The cover assembly 16 has a disc-shaped cover member 18 made of a conductive material, such as aluminum. The cover assembly 16 includes a terminal member 20, which is fixed to the cover member 18 and electrically insulated therefrom by an insulating member 22. The cover assembly 16 may include a filling opening 24, which can be plugged by a plug member 26.

[0058] The current collector assembly 10 includes a current collector 30. The current collector 30 has a current contact portion 32. The current contact portion 32 has a parallel long side 34 and a short side 36. The short side 36 is an annular side. The current contact portion 32 has an overall rectangular shape. The current contact portion 32 extends along the diameter of the contact surface 14. The current contact portion 32 is welded to the electrode assembly 12, specifically to the contact surface 14.

[0059] The current contact portion 32 includes a plurality of welds 38. The welds 38 are arranged in pairs in parallel. The welds 38 are parallel to the long side 34. The distances between the welds 38 and the long side 34, as well as the distances between them, are equal. In other words, the distance between one weld 38 and its nearest long side 34, the distance between another weld 38 and its nearest long side 34, and the distances between these welds 38 are the same.

[0060] The current contact portion 32 may include an alignment hole 39, which is an example of an alignment feature. The alignment hole 39 can be used to properly position the current contact portion 32 on the contact surface 14 of the electrode assembly 12.

[0061] The current collector 30 includes a blade portion 40. The blade portion 40 extends from a long side 34. The blade portion 40 has a first leg portion 42, a second leg portion 44, and a tapered portion 46. These portions are defined by a bend in the blade portion 40. The tapered portion 46 tapers towards its end and is preferably welded to the terminal member 20.

[0062] The legs 42 and 44 are configured such that when the cover assembly 16 is in its mounting position ( Figure 4 They can be stacked on top of each other and the current contact portion 32.

[0063] Reference Figure 2 and Figure 3 Another embodiment of the current collector 30, which differs from the previous embodiment, is depicted and described. The current contact portion 32 has a different shape, such that the short side 36 is straight and has rounded corners.

[0064] Reference Figure 4 The manufacture of the energy storage unit 50 is described in more detail. The energy storage unit 50 includes a canister 52. The canister 52 defines a space in which the current collector assembly 10 is disposed, such that the electrode assembly 12 engages with the canister 52. More specifically, the electrode assembly 12 is inserted into the canister 52 with the current collector 30 pre-bent. A first leg 42 is stacked on top of the current contact portion 32, a second leg 44 is stacked on top of the first leg 42, and a tapered portion 46 is stacked on top of the second leg 44. A cap assembly 16 is welded to the canister 52. Electrolyte is filled through a filling opening 24, which is subsequently closed by a stopper assembly 26.

[0065] Thermal simulations of a steady-state 10 A current showed a temperature increase that was 2 to 3 times smaller compared to existing technology configurations. Experimentally determined ESR was approximately 25% lower than that of conventional configurations.

[0066] The current collector 30 contributes only about 30% to the 10 ms ESR value. Although it is still the single largest contributor to the 10 ms ESR value of the energy storage unit 50, its resistance is significantly lower than that of conventional designs. List of reference numerals 10. Current collector assembly 12 Electrode assemblies 14 Contact Surface 16 Cover Components 18. Cover components 20 terminal components 22 Insulating components 24. Fill the opening 26. Plug components 30 current collector 32 Current contact section 34 Long side 36 Short side 38 Weld 39 Align the hole 40 Blade section 42 First leg 44 Second leg 46. ​​Conical section 50 Energy Storage Units (Supercapacitors) 52 cans

Claims

1. A current collector assembly (10) for a supercapacitor (50), the current collector assembly (10) comprising: An electrode assembly (12) having an axial contact surface (14); and a current collector (30) having a current contact portion (32) and a blade portion (40), wherein the current contact portion (32) has a straight long side (34) and a short side (36), wherein the blade portion (40) protrudes from the long side (34), wherein the length of the long side (34) is 0.8 to 1.0 times the diameter of the electrode assembly (12).

2. The current collector assembly (10) according to claim 1, wherein, The ratio of the length of the short side (36) to the length of the long side (34) is 1:2 to 1:

3.

3. The current collector assembly (10) according to any one of the preceding claims, wherein, The width of the blade portion (40) is 50% to 80% of the length of the long side (34), preferably 60% to 72%, preferably 63% to 69%, preferably 2 / 3.

4. The current collector assembly (10) according to any one of the preceding claims, wherein, The shape of the short side (36) is selected from any of the following: a straight short side; a straight short side with rounded corners; and a circular short side, preferably an annular short side.

5. The current collector assembly (10) according to any one of the preceding claims, wherein, The current contact portion (32) has an alignment feature formed therein, the alignment feature being configured such that the current contact portion (32) can be aligned on the contact surface (14), preferably centered.

6. The current collector assembly (10) according to any one of the preceding claims, wherein, The current contact portion (32) is welded to the contact surface (14), and at least one pair of welds (38) are formed parallel to the long side (34).

7. The current collector assembly (10) according to claim 6, wherein, The length of each weld (38) is 25% to 100% of the length of the long side (34), preferably 25% to 41%, preferably 30% to 36%, preferably 1 / 3.

8. The current collector assembly (10) according to claim 6 or 7, wherein, The weld (38) is equidistant from an imaginary line marking the diameter of the contact surface (14), and / or equidistant from the long side (34), and / or equidistant from an imaginary line that is itself equidistant from the long side (34).

9. The current collector assembly (10) according to any one of the preceding claims further includes a terminal member (20), wherein, The blade portion (40) has a tapered end (46) that is electrically fixed to the terminal member (20).

10. The current collector assembly (10) according to claim 9, further comprising a cover member (18) and an insulating member (22), wherein, The terminal member (20) is fixed to the cover member (18) via the insulating member (22) such that the cover member (18) and the terminal member (20) are electrically insulated from each other.

11. The current collector assembly (10) according to any one of the preceding claims, wherein, The blade portion (40) has at least one curved portion, which allows adjacent legs (42, 44) of the blade portion (40) to stack on top of each other parallel to the contact surface (14) without the adjacent legs (42, 44) contacting each other in a direction perpendicular to the contact surface (14).

12. A supercapacitor (50) configured for storing electrical energy, the supercapacitor (50) comprising a tank (52) and a current collector assembly (10) as described in any of the preceding claims, wherein, The electrode assembly (12) is inserted into the can (52) and electrically connected to the can (52).

13. The supercapacitor (50) according to claim 12, wherein, The can (52) is closed by a cover assembly (16) fixed to the can (52), preferably welded to the can (52), and the cover assembly (16) is preferably formed by the cover member (18), the insulating member (22) and the terminal member (20).

14. The supercapacitor according to claim 12 or 13, wherein, The blade portion (40) is bent at least once such that adjacent portions (42, 44) of the blade portion (40) are stacked on top of each other parallel to the contact surface (14) without the adjacent portions (42, 44) contacting each other in a direction perpendicular to the contact surface (14).

15. An energy storage module configured to provide electrical power to an electrical system as needed, the energy storage module comprising an energy storage unit and a control unit, the energy storage unit comprising a plurality of supercapacitors (50) according to any one of claims 12 to 14, the control unit controlling the charging and discharging of the energy storage unit.

16. The energy storage module according to claim 15, wherein, The control unit is configured to control the energy storage unit to achieve peak shaving of electrical load in the data center, preferably the AI ​​data center.

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