Preparation method of cylindrical hybrid energy storage element and cylindrical hybrid energy storage element

Abstract

The invention discloses a preparation method of a cylindrical hybrid energy storage element and the cylindrical hybrid energy storage element. The preparation method comprises the following steps: 1, manufacturing positive plates and negative plates of a first energy storage element and a second energy storage element; the first energy storage element is a super capacitor or a battery; the second energy storage element is a battery; 2, performing winding operation on at least one section of first energy storage element positive plate and negative plate, at least one section of second energy storage element positive plate and negative plate and the same diaphragm to obtain a hybrid energy storage element pole group; 3, connecting positive tabs led out from the positive plates of the first energy storage element and the second energy storage element with an external positive electrode; connecting negative tabs led out from the negative plates of the first energy storage element and the second energy storage element with an external negative electrode to obtain a semi-finished hybrid energy storage element; and 4, obtaining a finished product hybrid energy storage element. According to the invention, multiple sections of pole pieces can be wound to form a single pole group, and then internal parallel connection is directly carried out, so that the internal space utilization rate and the product energy density of cylindrical packaging are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of supercapacitor and lithium-ion battery manufacturing technology, and in particular to a method for preparing a cylindrical hybrid energy storage element (the energy storage element includes a supercapacitor and a battery) and a cylindrical hybrid energy storage element, specifically a method for preparing an internally parallel wound hybrid energy storage element and a cylindrical hybrid energy storage element. Background Technology

[0002] Currently, the process of winding cylindrical supercapacitors or batteries typically involves connecting the electrode plates (including positive and negative electrode plates) to the tabs, then winding them into an electrode assembly, and finally connecting the tabs to the positive and negative leads of the supercapacitor or battery, and finally assembling them into a product.

[0003] The advantages of cylindrical products are: standardization, high production efficiency, excellent energy density of assembled systems, superior consistency and thermal management potential.

[0004] Connecting supercapacitors and batteries in parallel is a classic design that leverages the strengths of both, offering significant advantages in many high-power applications. The core idea is to use the high power density (fast charging and discharging) of supercapacitors to compensate for the relatively low power density and poor rate performance of lithium-ion batteries; simultaneously, the high energy density (long-lasting power supply) of lithium-ion batteries compensates for the low energy density of supercapacitors. Connecting different battery systems in parallel allows for system design improvements that can enhance the overall performance of lithium-ion batteries, such as power density, energy density, and safety.

[0005] Currently, common parallel connection methods between supercapacitors and batteries, as well as between batteries, include external parallel connection and internal parallel connection. Internal parallel connection design primarily involves connecting multiple smaller wound electrode groups in parallel via internal current collectors, then encapsulating them in the same housing. If a cylindrical design is used, this requires secondary manufacturing and connection of the multiple wound electrode groups, resulting in low internal space utilization, difficulty in increasing volumetric energy density, and complex processes, leading to low overall production efficiency. External parallel connection, on the other hand, requires assembling the supercapacitor and battery separately into finished products before connecting them, similarly resulting in low production efficiency and low volumetric energy density.

[0006] Therefore, there is an urgent need to develop a technology that can solve the above-mentioned technical problems. Summary of the Invention

[0007] The purpose of this invention is to address the technical deficiencies of existing technologies by providing a method for preparing a cylindrical energy storage element and a cylindrical energy storage element.

[0008] Therefore, the present invention provides a method for preparing a cylindrical hybrid energy storage element, comprising the following steps:

[0009] The first step is to manufacture the positive and negative electrode plates of the first energy storage element, and the positive and negative electrode plates of the second energy storage element.

[0010] The first energy storage element is a supercapacitor or a battery; the second energy storage element is a battery.

[0011] The second step involves performing a winding operation of at least one section of the positive and negative electrode of the first energy storage element, at least one section of the positive and negative electrode of the second energy storage element, and the same separator to obtain a hybrid energy storage element electrode assembly.

[0012] The third step is to connect the positive tabs of the first energy storage element positive electrode plate and the positive tabs of the second energy storage element positive electrode plate to the external positive electrode of the product, respectively.

[0013] Furthermore, the negative electrode tabs led out from the negative electrode plate of the first energy storage element and the negative electrode tabs led out from the negative electrode plate of the second energy storage element are respectively connected to the external negative electrode of the product to obtain a semi-finished hybrid energy storage element.

[0014] The fourth step involves loading the semi-finished hybrid energy storage element into a cylindrical outer casing, followed by liquid injection and product cover sealing to obtain the finished cylindrical hybrid energy storage element.

[0015] In addition, the present invention also provides a cylindrical hybrid energy storage element, which is prepared by the preparation method of the cylindrical hybrid energy storage element as described above.

[0016] As can be seen from the technical solutions provided by the present invention above, compared with the prior art, the present invention provides a method for preparing a cylindrical hybrid energy storage element and a cylindrical hybrid energy storage element. Its design is scientific, which can wind multiple electrode segments to form a single electrode group and then directly connect them in parallel internally, instead of the traditional method of winding into multiple electrode groups and then connecting them in parallel internally. This can significantly simplify the parallel connection process. Compared with the traditional multiple electrode groups, the single electrode group used in the present invention can significantly improve the utilization rate of the internal space of the cylindrical package and increase the energy density of the product. At the same time, compared with multiple electrode groups in parallel, the internal parallel structure of the single electrode group can further reduce the internal resistance of the product, which has significant practical significance.

[0017] After testing, it was found that the present invention can obtain a cylindrical hybrid energy storage element (i.e., a hybrid supercapacitor or battery cell product with internal parallel winding of cylindrical sections) by mixing and winding multiple electrode segments.

[0018] It should be noted that the present invention first completes the fabrication of electrode sheets of different chemical systems (such as supercapacitor electrode sheets and battery electrode sheets, which are two different types of electrode sheets), and then realizes the winding of electrode sheets of different systems into electrode groups through winding control. The implementation method is simpler, and the positive and negative electrode foil materials of different systems can be selected according to the system requirements. It is only necessary to make good design when connecting to the external electrode tabs to avoid contact. The solution of the present invention is easier to automate production. Attached Figure Description

[0019] Figure 1 A flowchart illustrating a method for fabricating a cylindrical energy storage element provided by this invention;

[0020] Figure 2 This invention provides a schematic diagram of a design for an internally parallel wound electrode sheet with an electrode lead-out type.

[0021] Figure 3 In accordance with Figure 2 A schematic diagram of an electrode assembly formed by winding the electrode sheets;

[0022] Figure 4 This is a schematic diagram of a design for a fully tab-leaded internally parallel wound electrode sheet provided by the present invention;

[0023] Figure 5 In accordance with Figure 4 A schematic diagram of an electrode assembly formed by winding the electrode sheets;

[0024] Figure 6 A cross-sectional view of a cylindrical energy storage element provided by the present invention;

[0025] In the diagram: 1-Separator, 2-First negative electrode plate, 3-First positive electrode plate, 4-First negative electrode lead-out tab, 5-First positive electrode lead-out tab, 6-Second negative electrode plate, 7-Second positive electrode plate, 8-Second negative electrode lead-out tab, 9-Second positive electrode lead-out tab;

[0026] 10-Hybrid energy storage element electrode group, 11-Positive electrode summary lead-out tab, 12-Negative electrode summary lead-out tab;

[0027] 13 - Positive electrode leads to the full-polarity ear foil; 14 - Negative electrode leads to the full-polarity ear foil;

[0028] 15-Product outer casing, 16-Hybrid energy storage element electrode group, 17-Product external positive electrode, 18-Product external negative electrode, 19-Product cover plate. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0031] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0033] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0034] See Figures 1 to 6 This invention provides a method for preparing a cylindrical hybrid energy storage element (the energy storage element includes a supercapacitor and a battery), comprising the following steps:

[0035] The first step is to manufacture the positive and negative electrode plates of the first energy storage element, and the positive and negative electrode plates of the second energy storage element.

[0036] The first energy storage element is a supercapacitor or a battery; the second energy storage element is a battery.

[0037] In the first step, specifically, the positive and negative electrodes of the supercapacitor and the positive and negative electrodes of the battery both adopt a non-full tab (non-full tab includes single tab or multiple tabs) lead-out structure, or both adopt a full tab lead-out structure. The connection method between the inner tab and the positive and negative electrodes can be riveting, cold welding, laser welding, ultrasonic welding, etc.

[0038] It should be noted that, in the first step of this invention, in specific implementation, for non-full tab structure (i.e., internal tab lead-out structure), the tabs need to be connected on the positive and negative electrode plates according to the design by means of riveting, cold welding, laser welding, ultrasonic welding, etc.; for full tab structure, a suitable foil width needs to be designed.

[0039] It should be noted that the positive electrode active material on the positive electrode sheet can be one or more of activated carbon, lithium iron phosphate, lithium manganese oxide, lithium cobalt oxide, ternary materials, etc., and the negative electrode active material on the negative electrode sheet can be one or more of activated carbon, graphite, hard carbon, silicon carbide, etc.

[0040] It should be noted that the manufacturing techniques for the supercapacitor positive and negative electrode plates, as well as the battery positive and negative electrode plates of the present invention, can adopt existing mature conventional techniques, which will not be elaborated here.

[0041] The second step involves performing a winding operation of at least one section of the positive and negative electrode of the first energy storage element, at least one section of the positive and negative electrode of the second energy storage element, and the same separator to obtain a hybrid energy storage element electrode assembly.

[0042] In this invention, specifically, the second step includes either a first electrode design scheme or a second electrode design scheme.

[0043] The specific design scheme for the first electrode is as follows: In the second step, the number of positive electrodes for both the first and second energy storage elements is multiple.

[0044] The negative electrode of the first energy storage element corresponding to the positive electrode of the multiple segments of the first energy storage element is the same negative electrode (i.e., the same whole segment of the first energy storage element negative electrode), and the negative electrode of the second energy storage element corresponding to the positive electrode of the multiple segments of the second energy storage element is the same negative electrode (i.e., the same whole segment of the second energy storage element negative electrode).

[0045] The second step is as follows: perform a winding operation of multiple segments of the first energy storage element positive electrode sheet and one first energy storage element negative electrode sheet, multiple segments of the second energy storage element positive electrode sheet and one second energy storage element negative electrode sheet with the same separator to obtain a hybrid energy storage element electrode group.

[0046] The specific design scheme for the second electrode is as follows: In the second step, the number of negative electrodes of the first energy storage element and the second energy storage element are both multiple segments;

[0047] The positive electrode of the first energy storage element corresponding to the negative electrode of the multiple segments of the first energy storage element is the same positive electrode (i.e., the same whole segment of the first energy storage element positive electrode), and the positive electrode of the second energy storage element corresponding to the negative electrode of the multiple segments of the second energy storage element is the same positive electrode (i.e., the same whole segment of the second energy storage element positive electrode).

[0048] The second step is as follows: perform a winding operation of a first energy storage element positive electrode sheet and multiple first energy storage element negative electrode sheets, a second energy storage element positive electrode sheet and multiple second energy storage element negative electrode sheets with the same separator to obtain a hybrid energy storage element electrode group.

[0049] In summary, the hybrid energy storage element in this invention is not limited to a combination of supercapacitor and battery, but can also be a combination of batteries (such as a ternary cathode mixed with lithium manganese oxide cathode, a graphite anode mixed with silicon-carbon anode, etc.). The cathode can be multi-segmented, and the anode can be single-segmented, or the cathode can be single-segmented and the anode multi-segmented.

[0050] In the second step, specifically, a winding operation is performed on a supercapacitor or battery positive electrode sheet of a preset first length (e.g., 1390 mm), a supercapacitor or battery negative electrode sheet of a preset second length (e.g., 1360 mm), a battery positive electrode sheet of a preset third length (e.g., 1390 mm), and a battery negative electrode sheet of a preset fourth length (e.g., 1360 mm) with the same separator to obtain a hybrid energy storage element electrode assembly (i.e., requiring the two battery electrode sheets to be mixed, each of which is a different material system).

[0051] In the second step, specifically, the positive and negative electrode plates of the first energy storage element are located on both sides of the separator and are symmetrically arranged (e.g., symmetrically arranged vertically).

[0052] The positive and negative electrodes of the second energy storage element are located on both sides of the separator and are symmetrically arranged (e.g., symmetrically arranged vertically).

[0053] It should be noted that in the second step, in order to realize the winding operation of multiple segments of supercapacitor positive and negative electrode plates and multiple segments of battery positive and negative electrode plates on the separator, the winding control can be used to cut off the electrode plate of each segment of supercapacitor or battery system after winding, keep the separator continuous, and then proceed with the winding of the next segment of electrode plate.

[0054] It should be noted that after the electrode sheet is connected to the tab, the electrode sheet can be wound in segments by controlling existing, technologically mature winding cutters and electrode sheet feeding mechanisms. Each segment of the electrode sheet can be either a non-full tab (including single tab or multi-tab) or a full tab lead-out.

[0055] It should be noted that, in the second step of this invention, the length of each positive and negative electrode segment is pre-designed. Each positive and negative electrode segment can be designed with different system combinations, and the length of each segment can be the same or different. The number of segments of the electrode can be two or more, and multi-segment winding is achieved through existing, technically mature equipment cutting and feeding mechanisms.

[0056] It should be noted that, for this invention, by adding multiple existing and technically mature winding machine feeding mechanisms, it is possible to achieve mixed winding of multiple electrode segments, such as internal mixing and parallel connection of different lithium-ion battery systems, supercapacitor systems, etc., and the performance of individual products can be comprehensively improved.

[0057] The third step is to connect the positive tabs of the first energy storage element positive electrode plate and the positive tabs of the second energy storage element positive electrode plate to the external positive electrode of the product, respectively.

[0058] Furthermore, the negative electrode tabs led out from the negative electrode plate of the first energy storage element and the negative electrode tabs led out from the negative electrode plate of the second energy storage element are respectively connected to the external negative electrode of the product to obtain a semi-finished hybrid energy storage element.

[0059] In the third step, specifically, the connection methods between the positive electrode tab and the external positive electrode of the product, and between the negative electrode tab and the external negative electrode of the product, can be riveting, cold welding, laser welding, ultrasonic welding, etc.

[0060] It should be noted that the positive and negative terminals of the hybrid energy storage element electrode group are respectively led out with tabs and connected to the positive and negative terminals of the product (i.e., the external negative terminal and the external positive terminal of the product). The positive and negative terminals can be the same end or opposite ends.

[0061] It should be noted that, in the third step of this invention, each positive and negative electrode segment is connected to the positive and negative electrode leads of the product (i.e., the external negative and positive electrodes of the product) through the led-out tabs, thereby achieving parallel connection.

[0062] The fourth step involves loading the semi-finished hybrid energy storage element into a cylindrical outer casing, followed by electrolyte injection and product cover sealing to obtain the finished cylindrical hybrid energy storage element (i.e., an internally parallel wound cylindrical hybrid supercapacitor or battery).

[0063] It should be noted that the electrolyte manufacturing technology can adopt existing and mature conventional technologies, which will not be elaborated here.

[0064] In the fourth step, in practice, the cylindrical product outer shell has only one opening, for example, only the top opening, and this opening is encapsulated and sealed by the product cover plate.

[0065] In the fourth step, specifically, the external negative electrode and the external positive electrode of the product can be set on the product cover plate, and they are spaced apart from each other and insulated from each other.

[0066] The specific structural design of each segment of the positive and negative electrode plates is explained below, based on whether the electrode structure belongs to a non-full tab structure or a full tab structure:

[0067] I. See also Figure 2 , Figure 3 As shown, for a section of a supercapacitor's positive and negative electrodes or a section of a battery's positive and negative electrodes, its non-full tab (in this case, non-full tab includes a single tab) lead-out structure is as follows: Figure 2 , Figure 3 As shown, a first positive electrode plate 3 and a second positive electrode plate 7 are arranged at intervals on the front side of the diaphragm 1;

[0068] On the rear side of the diaphragm 1, at positions corresponding to the first positive electrode 3 and the second positive electrode 7, a first negative electrode 2 and a second negative electrode 6 are provided;

[0069] On the first positive electrode plate 3 and the second positive electrode plate 7, the first positive electrode lead-out tab 5 and the second positive electrode lead-out tab 9 are respectively connected (i.e. led out);

[0070] The first negative electrode 2 and the second negative electrode 6 are respectively connected to (i.e. led out) the first negative electrode lead-out tab 4 and the second negative electrode lead-out tab 8.

[0071] It should be noted that the first positive electrode 3 and the first negative electrode 2 are the positive and negative electrodes of the supercapacitor, while the second positive electrode 7 and the second negative electrode 6 are the positive and negative electrodes of the battery, that is, the electrodes of two energy storage elements with different systems.

[0072] based on Figure 2 , Figure 3 The electrode structure design of the non-full-tie lead-out structure, when the hybrid energy storage element electrode group 10 is wound to obtain the hybrid energy storage element electrode group 10, has a positive electrode summary lead-out electrode 11 (including multiple single electrodes) and a negative electrode summary lead-out electrode 12 (including multiple single electrodes).

[0073] II. See Figure 4 , Figure 5 As shown, for a section of a supercapacitor's positive and negative electrodes or a section of a battery's positive and negative electrodes, its total tab lead-out structure is as follows: Figure 4 , Figure 5 As shown, a first positive electrode plate 3 and a second positive electrode plate 7 are arranged at intervals on the front side of the diaphragm 1;

[0074] On the rear side of the diaphragm 1, at positions corresponding to the first positive electrode 3 and the second positive electrode 7, a first negative electrode 2 and a second negative electrode 6 are provided;

[0075] The first positive electrode 3 and the first negative electrode 2, as well as the second positive electrode 7 and the second negative electrode 6, are all omnipolar electrode plates.

[0076] It should be noted that the first positive electrode 3 and the first negative electrode 2 are the positive and negative electrodes of the supercapacitor, while the second positive electrode 7 and the second negative electrode 6 are the positive and negative electrodes of the battery, that is, the electrodes of two energy storage elements with different systems.

[0077] based on Figure 4 , Figure 5 The electrode design of the all-electrode lead-out structure, when the hybrid energy storage element electrode group 10 is wound to obtain the hybrid energy storage element electrode group 10, has a positive lead-out all-electrode foil 13 and a negative lead-out all-electrode foil 14 on the hybrid energy storage element electrode group 10.

[0078] Based on the above-mentioned method for preparing a cylindrical hybrid energy storage element (including a supercapacitor and a battery) provided by the present invention, the present invention discloses a cylindrical hybrid energy storage element (i.e., a hybrid supercapacitor or battery with internal parallel winding of a cylindrical shape), which is prepared by the method for preparing a cylindrical hybrid energy storage element (including a supercapacitor and a battery) provided by the present invention.

[0079] See Figure 6 As shown, the cylindrical hybrid energy storage element includes a cylindrical outer casing 15.

[0080] The cylindrical outer casing 15 contains a hybrid energy storage element electrode assembly 16, which is filled with electrolyte.

[0081] The hybrid energy storage element electrode assembly 16 includes at least one section of a first energy storage element positive electrode and a negative electrode, at least one section of a second energy storage element positive electrode and a negative electrode, and a separator, which is obtained by performing a winding operation on the positive and negative electrode of the supercapacitor, the positive and negative electrode of the battery, and the separator.

[0082] The first energy storage element is a supercapacitor or a battery; the second energy storage element is a battery.

[0083] For the hybrid energy storage element electrode group 16, the positive tabs (single tab, multiple tabs or all tabs) led out from each positive electrode segment are connected to the external positive electrode 17 of the product, and the negative tabs (single tab, multiple tabs or all tabs) led out from each negative electrode segment are connected to the external negative electrode 18 of the product.

[0084] In this invention, specifically, a product cover plate 19 is provided at the top opening of the cylindrical outer shell of the product.

[0085] In practice, the product cover plate 19 is provided with an external negative electrode and an external positive electrode, which are spaced apart from each other and insulated from each other.

[0086] It should be noted that the cylindrical hybrid energy storage element (i.e., the internally parallel wound cylindrical hybrid supercapacitor or battery) provided by this invention mainly includes an electrode assembly, a product cover plate, an electrolyte, and an external shell. By dividing the individual electrode assembly into multiple segments, winding them in sections, and leading out an electrode tab for each segment, and connecting them to the external electrode tab (i.e., the external negative and positive electrodes of the product) through riveting, ultrasonic welding, or laser welding, the cylindrical supercapacitor and battery product can be internally paralleled, which can significantly reduce the internal resistance of the product. Furthermore, by mixing and winding different types of electrode sheets, the overall performance of the product can be improved, and the production process is simple and convenient.

[0087] To better understand the technical solution of the present invention, the following specific embodiments will be used to illustrate the technical solution of the present invention.

[0088] Example 1.

[0089] The present invention provides a method for preparing a cylindrical hybrid energy storage element (specifically, an internally parallel wound cylindrical hybrid supercapacitor or battery), which includes the following steps:

[0090] The first step is to fabricate the positive and negative activated carbon electrodes for the supercapacitor, wherein the coating amount of the positive electrode active material (specifically carbon) is 5.0 mg / cm³. 2 The coating amount of the negative electrode active material (specifically carbon) is 5.0 mg / cm². 2 The width of both the positive and negative electrode plates is 47mm;

[0091] Furthermore, the positive and negative electrode sheets for lithium titanate batteries are fabricated, wherein the positive electrode active material is LiMn2O4 with a coating amount of 22 mg / cm³. 2 The negative electrode active material is Li4Ti5O 12 Coating amount 12mg / cm 2 The width of both the positive and negative electrode plates is 47mm;

[0092] The second step involves cold welding aluminum tabs onto the positive electrode of the supercapacitor, with a welding spacing of 1390mm, and cold welding aluminum tabs onto the negative electrode of the supercapacitor, with a welding spacing of 1360mm.

[0093] Aluminum tabs are cold-welded onto the positive electrode of a lithium titanate battery with a welding spacing of 1390mm. Aluminum tabs are also cold-welded onto the negative electrode of a lithium titanate battery with a welding spacing of 1360mm.

[0094] The third step involves manually or using a winding machine (electrode winding machine) to wind multiple segments of the electrode sheets and adjust the alignment of the electrode tabs. The first segment winds the positive and negative electrode sheets of the supercapacitor, with the positive electrode sheet being 1390mm long and the negative electrode sheet being 1360mm long. After winding, the segments are cut. The second segment winds the positive and negative electrode sheets of the lithium titanate battery, with the positive electrode sheet being 1390mm long and the negative electrode sheet being 1360mm long. A 30µm thick cellulose separator is used to separate the electrodes, resulting in a hybrid capacitor electrode assembly.

[0095] The fourth step involves drying the electrode assembly, then riveting the two aluminum tabs leading out from the positive electrode to the external positive electrode on the product cover (i.e., the product cover plate), and riveting the two aluminum tabs leading out from the negative electrode to the external negative electrode on the product cover plate. After liquid injection and encapsulation, a hybrid supercapacitor product with parallel dimensions of φ35×61mm (i.e., diameter×height) is obtained.

[0096] Comparative Example 1.

[0097] The traditional method for fabricating a parallel hybrid supercapacitor within an electrode group includes the following steps:

[0098] The first step is to fabricate the positive and negative activated carbon electrodes for the supercapacitor, wherein the coating amount of the positive electrode active material (specifically carbon) is 5.0 mg / cm³. 2 The negative electrode active material (specifically carbon) has a coating amount of 5.0 mg / cm³. 2 The width of both the positive and negative electrode plates is 47mm;

[0099] Furthermore, the positive and negative electrode sheets for lithium titanate batteries are fabricated, wherein the positive electrode active material is LiMn2O4 with a coating amount of 22 mg / cm³. 2 The negative electrode active material is Li4Ti5O12, with a coating amount of 12 mg / cm². 2 ;

[0100] The second step involves cold welding aluminum tabs onto the positive electrode of the supercapacitor, with a welding spacing of 1390mm, and cold welding aluminum tabs onto the negative electrode of the supercapacitor, with a welding spacing of 1360mm.

[0101] Aluminum tabs are cold-welded onto the positive electrode of a lithium titanate battery with a welding spacing of 1390mm, and aluminum tabs are cold-welded onto the negative electrode of a lithium titanate battery with a welding spacing of 1360mm.

[0102] The third step is to wind the electrode groups separately by manual means or by winding equipment (electrode group winding machine). The length of the positive electrode of the supercapacitor electrode group and the lithium titanate battery electrode group is 1390mm, and the length of the negative electrode is 1360mm. The separator is a 30um thick cellulose separator.

[0103] The fourth step involves drying the electrode groups, then riveting the aluminum tabs leading out from the positive electrodes of the two electrode groups to the external positive electrode on the product cover (i.e., the product cover plate), and riveting the two aluminum tabs leading out from the negative electrodes of the two electrode groups to the external negative electrode on the product cover plate. After liquid injection and encapsulation, a supercapacitor product with internal electrode group parallel dimensions of φ49×61mm (i.e., diameter×height, to accommodate two electrode groups) is obtained.

[0104] Example 2.

[0105] The present invention provides a method for preparing a cylindrical hybrid energy storage element (specifically, an internally parallel wound cylindrical hybrid supercapacitor or battery), which includes the following steps:

[0106] The first step is to fabricate the positive and negative activated carbon electrodes for the supercapacitor. The electrodes adopt a full-tab design, with a coating width of 43 mm and a blank foil width of 7 mm. The coating amount of the positive electrode active material (specifically carbon) is 5.0 mg / cm³. 2 The coating amount of the negative electrode active material (specifically carbon) is 5.0 mg / cm². 2 ;

[0107] Furthermore, the positive and negative electrode sheets for lithium titanate batteries are manufactured. The electrode sheets adopt a full tab design, with a coating width of 43 mm and a blank foil width of 7 mm. The positive electrode active material is LiMn2O4, with a coating amount of 22 mg / cm³. 2 The negative electrode active material is Li4Ti5O 12 Coating amount 12mg / cm 2 ;

[0108] The second step involves segmenting and winding multiple electrode sections manually or using a winding machine (electrode winding machine). The first section winds the positive and negative electrode sections of the supercapacitor, with the positive electrode section being 1390mm long and the negative electrode section being 1360mm long. After winding, the sections are cut. The second section winds the positive and negative electrode sections of the lithium titanate battery, with the positive electrode section being 1390mm long and the negative electrode section being 1360mm long. A 30µm thick cellulose separator is used, resulting in a hybrid supercapacitor electrode assembly.

[0109] The third step involves drying the electrode assembly, then laser welding the positive and negative aluminum foils to the positive and negative current collectors respectively. The welded current collectors are then laser welded to the positive and negative electrodes on the outside of the hybrid capacitor. Finally, after liquid injection and encapsulation, a hybrid supercapacitor product with a parallel dimension of φ35×61mm (i.e., diameter×height) is obtained.

[0110] Comparative Example 2.

[0111] The traditional method for fabricating a parallel-connected hybrid all-electrode supercapacitor includes the following steps:

[0112] The first step is to fabricate the positive and negative activated carbon electrodes of the supercapacitor, with a coating width of 43 mm and an empty foil width of 7 mm. The coating amount of the positive active material (specifically carbon) is 5.0 mg / cm². 2 The coating amount of the negative electrode active material (specifically carbon) is 5.0 mg / cm². 2 ;

[0113] Furthermore, the positive and negative electrode sheets for lithium titanate batteries were fabricated with a coating width of 43 mm and an empty foil width of 7 mm. The positive electrode active material was LiMn2O4, with a coating amount of 22 mg / cm³. 2 The negative electrode active material is Li4Ti5O12, with a coating amount of 12 mg / cm². 2 ;

[0114] The second step is to wind the electrode groups separately by manual means or by winding equipment (electrode group winding machine). The length of the positive electrode of the supercapacitor electrode group and the lithium titanate battery electrode group is 1390mm, and the length of the negative electrode is 1360mm. The separator is a 30um thick cellulose separator.

[0115] The third step involves laser welding the positive and negative aluminum foils to the positive and negative current collectors, respectively, after the electrode groups are dried. The welded current collectors are then laser welded to the positive and negative electrodes of the hybrid capacitor. After liquid injection and encapsulation, a full-tab supercapacitor product with an internal electrode group parallel size of φ49×61mm (i.e., diameter×height, to accommodate two electrode groups) is obtained.

[0116] Four types of internally parallel supercapacitors prepared based on Examples 1, 2, 1, and 2 were placed in an ambient temperature of 25±5℃ and tested for capacitance, internal resistance, and volumetric energy density with a current of 20A. The results are recorded in Table 1 below.

[0117] Table 1:

[0118]

[0119] As can be seen from Table 1 above, the volumetric energy density of the cylindrical hybrid energy storage element (specifically, the internally parallel wound cylindrical hybrid supercapacitor) prepared using the present invention is nearly double that of the traditional internally parallel hybrid capacitor. The internal resistance of Comparative Example 1 is reduced by 14.6% compared to Example 1, and the internal resistance of Comparative Example 2 is reduced by 21.1% compared to Example 2.

[0120] Compared with existing technologies, the method for preparing cylindrical hybrid energy storage elements (specifically, internally parallel wound cylindrical hybrid supercapacitors or batteries) provided by this invention has the following beneficial effects:

[0121] 1. Compared with the traditional manufacturing process of internally parallel cylindrical hybrid capacitors or batteries, the present invention adopts a multi-segment electrode design, which is wound into a single electrode group and then assembled in production. This can significantly improve assembly production efficiency, reduce internal connections, reduce product internal resistance, and improve product power characteristics and volumetric energy density.

[0122] 2. In this invention, the wound electrode sheet can be divided into two or more segments, and each segment can have a different electrode sheet design. Multiple electrode sheets can be mixed and wound simply by controlling the winding process, which is of great significance for improving the overall performance of cylindrical products.

[0123] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a cylindrical hybrid energy storage element, characterized in that, Includes the following steps: The first step is to manufacture the positive and negative electrode plates of the first energy storage element, and the positive and negative electrode plates of the second energy storage element. The first energy storage element is a supercapacitor or a battery; the second energy storage element is a battery. The second step involves performing a winding operation of at least one section of the positive and negative electrode of the first energy storage element, at least one section of the positive and negative electrode of the second energy storage element, and the same separator to obtain a hybrid energy storage element electrode assembly. The third step is to connect the positive tabs of the first energy storage element positive electrode plate and the positive tabs of the second energy storage element positive electrode plate to the external positive electrode of the product, respectively. Furthermore, the negative electrode tabs led out from the negative electrode plate of the first energy storage element and the negative electrode tabs led out from the negative electrode plate of the second energy storage element are respectively connected to the external negative electrode of the product to obtain a semi-finished hybrid energy storage element. The fourth step involves loading the semi-finished hybrid energy storage element into a cylindrical outer casing, followed by liquid injection and product cover sealing to obtain the finished cylindrical hybrid energy storage element.

2. The method for preparing the cylindrical hybrid energy storage element as described in claim 1, characterized in that, The second step includes either a first electrode design scheme or a second electrode design scheme; The specific design scheme for the first electrode is as follows: In the second step, the number of positive electrodes for both the first and second energy storage elements is multiple. The negative electrode of the first energy storage element corresponding to the positive electrode of the multi-segment first energy storage element is the same negative electrode, and the negative electrode of the second energy storage element corresponding to the positive electrode of the multi-segment second energy storage element is the same negative electrode. The second step is as follows: perform a winding operation of multiple segments of the first energy storage element positive electrode sheet and one first energy storage element negative electrode sheet, multiple segments of the second energy storage element positive electrode sheet and one second energy storage element negative electrode sheet with the same separator to obtain a hybrid energy storage element electrode group. The specific design scheme for the second electrode is as follows: In the second step, the number of negative electrodes of the first energy storage element and the second energy storage element are both multiple segments; The positive electrode of the first energy storage element corresponding to the negative electrode of the multi-segment first energy storage element is the same positive electrode, and the positive electrode of the second energy storage element corresponding to the negative electrode of the multi-segment second energy storage element is the same positive electrode. The second step is as follows: perform a winding operation of a first energy storage element positive electrode sheet and multiple first energy storage element negative electrode sheets, a second energy storage element positive electrode sheet and multiple second energy storage element negative electrode sheets with the same separator to obtain a hybrid energy storage element electrode group.

3. The method for preparing the cylindrical hybrid energy storage element as described in claim 1, characterized in that, In the second step, the positive and negative electrode plates of the first energy storage element are located on both sides of the separator and are arranged symmetrically. The positive and negative electrodes of the second energy storage element are located on both sides of the separator and are arranged symmetrically.

4. The method for preparing the cylindrical hybrid energy storage element as described in claim 3, characterized in that, The front side of the diaphragm (1) is provided with a first section of positive electrode (3) and a second section of positive electrode (7) spaced apart; On the rear side of the diaphragm (1), at positions corresponding to the first positive electrode (3) and the second positive electrode (7), a first negative electrode (2) and a second negative electrode (6) are provided; The first positive electrode plate (3) and the second positive electrode plate (7) are respectively connected to the first positive electrode lead-out tab (5) and the second positive electrode lead-out tab (9); The first negative electrode tab (4) and the second negative electrode tab (8) are respectively connected to the first negative electrode plate (2) and the second negative electrode plate (6).

5. The method for preparing the cylindrical hybrid energy storage element as described in claim 3, characterized in that, The front side of the diaphragm (1) is provided with a first section of positive electrode (3) and a second section of positive electrode (7) spaced apart; On the rear side of the diaphragm (1), at positions corresponding to the first positive electrode (3) and the second positive electrode (7), a first negative electrode (2) and a second negative electrode (6) are provided; The first positive electrode (3), the first negative electrode (2), the second positive electrode (7), and the second negative electrode (6) are all full-tab electrode plates.

6. The method for preparing the cylindrical hybrid energy storage element as described in claim 1, characterized in that, In the fourth step, the external negative electrode and the external positive electrode of the product are set on the product cover plate, and are spaced apart from each other and insulated from each other.

7. A cylindrical hybrid energy storage element, characterized in that, It is prepared using the method for preparing a cylindrical hybrid energy storage element as described in any one of claims 1 to 6.

8. The cylindrical hybrid energy storage element as described in claim 7, characterized in that, Includes a cylindrical outer casing (15); The cylindrical outer casing (15) of the product is equipped with a hybrid energy storage element electrode assembly (16) and is filled with electrolyte; The hybrid energy storage element electrode assembly (16) includes at least one section of a first energy storage element positive electrode and a negative electrode, at least one section of a second energy storage element positive electrode and a negative electrode, and a separator, which is obtained by performing a winding operation on each section of the positive electrode, the negative electrode, and the separator; The first energy storage element is a supercapacitor or a battery; the second energy storage element is a battery.

9. The cylindrical hybrid energy storage element as described in claim 8, characterized in that, For the hybrid energy storage element electrode group (16), the positive electrode tabs of each positive electrode segment are connected to the external positive electrode (17) of the product, and the negative electrode tabs of each negative electrode segment are connected to the external negative electrode (18) of the product.

10. The cylindrical hybrid energy storage element as described in claim 8, characterized in that, The top opening of the cylindrical product outer casing is sealed with a product cover plate (19); The product cover plate (19) is provided with an external negative electrode and an external positive electrode, which are spaced apart from each other and insulated from each other.

Images