Electrochemical device and electric equipment

Abstract

The embodiment of the invention relates to the technical field of electrochemical devices, and particularly discloses an electrochemical device and electric equipment. The electrochemical device comprises a housing, an electrode assembly, a tab, an adapter and a pole. The shell is provided with a containing cavity used for containing the electrode assembly, the shell further comprises a main body and an installation table body which are communicated, the containing cavity is located in the main body, the installation table body is internally provided with a containing cavity, the containing cavity is communicated with the containing cavity, and the thickness of the main body is larger than that of the installation table body. The plurality of tabs are folded in the thickness direction to form a multi-tab structure, the multi-tab structure comprises a folding part and a tab bundling part, the tab bundling part extends in the first direction, the tab bundling part is directly connected with the adapter, the adapter extends in the accommodating cavity in the first direction, one end of the pole is connected to the adapter, and the other end of the pole extends out of the mounting table body from the accommodating cavity. The space utilization rate of the electrochemical device in the thickness direction is improved, and the energy density is further improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of electrochemical devices, and in particular to an electrochemical device and electrical equipment. Background Art

[0002] With the rapid development of portable electronic devices and new energy technologies, lithium-ion batteries, as core energy storage devices, have consistently focused on optimizing their comprehensive performance and innovation. Compared to soft-pack or aluminum-cased structures, steel-cased batteries offer greater mechanical strength and deformation resistance, as well as significant safety and stability advantages under complex operating conditions, making them the preferred solution for specific applications.

[0003] However, in the industrial context of continuously upgrading demands for miniaturization and high energy density of battery systems, the technical shortcomings of steel-shell batteries have gradually become apparent: limited by the inherent physical properties and structural design constraints of the shell material, the improvement of its energy density faces multiple technical bottlenecks.

[0004] The inventors have discovered that in the aforementioned portable electronic devices and other small electronic devices, consumer electronics, medical electronics, and other fields, there are requirements for thinner and lighter batteries, as well as for maintaining and increasing energy density. Currently, battery designs for these devices require reducing the thickness of the battery. In many designs, the battery includes an electrode assembly, a tab, and a post. The tab extends from the electrode assembly and is electrically connected to the post via an adapter. Due to current welding process limitations, the weld mark is long, requiring a double-bend structure, which easily takes up more battery space and reduces the battery's energy density. Summary of the Invention

[0005] Based on this, the purpose of this application is to provide an electrochemical device and electrical equipment, aiming to improve the current design status of steel shell battery structure and reduce the waste of size and energy density caused by multiple bending of the tabs.

[0006] According to a first aspect of the present application, to address the aforementioned technical problems, a technical solution is provided, comprising: an electrochemical device comprising a housing, an electrode assembly, a tab, an adapter, and a post. The housing comprises a receiving cavity for accommodating the electrode assembly, wherein the housing further comprises a main body and a mounting platform that are interconnected. The receiving cavity is located within the main body, and the mounting platform comprises a receiving cavity that is connected to the receiving cavity. Along the thickness direction of the electrochemical device, the main body is thicker than the mounting platform. Multiple tabs are gathered along the thickness direction to form a multi-tab structure. The multi-tab structure comprises a gathering portion and a tab clustering portion. The tab clustering portion extends along a first direction and is directly connected to the adapter. The adapter extends along the first direction within the receiving cavity. One end of the post is connected to the adapter, and the other end extends from the receiving cavity to the mounting platform. The first direction is perpendicular to the thickness direction of the electrochemical device. Direct connection between the tab clustering portion and the adapter refers to direct connection between the two components, which may be achieved by welding, conductive adhesive, or other methods.

[0007] The tabs and the pole posts are connected to the adapter, and the tabs, the adapter, and the pole posts are stacked within the receiving cavity and extend beyond the mounting platform. The multi-tab structure is formed by a plurality of tabs being gathered in the thickness direction and then connected to the adapter. The portion of the tabs that are gathered along the thickness direction of the electrochemical device is a gathered portion, which is bundled together to form a tab clustering portion. The tab clustering portion is connected to the adapter so that the tabs only bend once when gathered and do not need to be bent when connected to the adapter. This reduces the number of times the tabs bend within the receiving cavity and the receiving cavity, thereby reducing the space occupied by the tabs within the housing. This reduces the thickness of the tabs and the pole posts in the thickness direction of the electrochemical device, thereby improving the space utilization of the electrochemical device in the thickness direction in terms of both the housing and the electrical connection structure, and thereby improving the energy density of the electrochemical device.

[0008] In some preferred embodiments, the adapter and the tab cluster at least partially overlap, and a first weld mark region exists in the region where the tab and adapter overlap. The length D of the first weld mark region in the adapter extension direction satisfies the following relationship: 0.4 mm ≤ D ≤ 0.7 mm. In other words, the first weld mark region in this application is relatively short, eliminating the need for a secondary bend in the tab to provide more space to accommodate the weld mark portion, facilitating tab extension and reducing the number of tab bends, thereby improving energy density.

[0009] In some preferred embodiments, the length D of the first weld mark area in the extension direction of the adapter satisfies the following condition: 0.4 mm ≤ D ≤ 0.6 mm. Based on the above technical solution, the length of the first weld mark area is further optimized, providing more space for tab extension, reducing the number of tab bends, and further improving energy density.

[0010] In some preferred embodiments, the first weld mark area is formed by laser welding the tab and the adapter. That is, the present application uses laser welding to form a first weld mark area with welding strength and a small length, thereby achieving the purpose of improving energy density.

[0011] In some preferred embodiments, the end of the tab cluster portion within the accommodating cavity has a second weld mark area, and the second weld mark area is formed by melting when laser cutting multiple tabs. As a result, the ends of the multi-layer tabs can be melted into a whole during laser cutting, making it easier to weld the tabs to the adapter. Since laser welding requires all tabs to fit together, the tabs may not fit together completely after being gathered, otherwise there will be technical problems such as explosion points. Therefore, laser cutting of the tabs is used to form a welding area at the end to achieve welding and fixation of multiple tabs, reducing the risk of explosion points. On the other hand, after the multi-layer tabs are welded and fixed, it is more convenient to weld the tabs to the adapter.

[0012] In some preferred embodiments, the first weld mark area is formed by laser welding the adapter and at least two layers of tabs. Welding more than two layers of tabs makes the entire structure more stable.

[0013] In some preferred embodiments, along the first direction, the plurality of tabs are aligned at the end of the tab cluster away from the electrode assembly, thereby improving the connection strength between the multiple tabs and the welding strength between the tab cluster and the adapter.

[0014] In some preferred embodiments, the tab cluster and the terminal post are located on opposite sides of the adapter along the thickness of the electrochemical device. This structure fully utilizes the space on both sides of the adapter, allowing the tabs and terminal post to connect to the adapter over a larger area, thereby improving the connection strength, and enhancing the performance and service life of the electrochemical device.

[0015] In some preferred embodiments, along the thickness direction of the electrochemical device, the tab cluster and the electrode column are arranged on the same side of the adapter. This structure improves the internal space utilization of the electrochemical device and thus increases the energy density of the electrochemical device.

[0016] In some preferred embodiments, along the thickness direction of the electrochemical device, the sum of the thickness of the adapter and the thickness of the tab cluster is less than the thickness of the electrode within the accommodating cavity. This allows the electrode to extend into the accommodating cavity to provide space for the stacked structure between the adapter and the tab, further improving the space utilization of the electrochemical device in the thickness direction, thereby increasing the energy density of the electrochemical device.

[0017] In some preferred embodiments, along the second direction, a side surface of the main body proximate to the mounting platform and a portion of the outer surface of the mounting platform jointly form a receiving space. The mounting platform is provided with an opening, and the terminal extends from the receiving cavity through the opening. The electrochemical device further includes an adhesive layer disposed around the opening, with one side of the adhesive layer attached to the outer surface of the mounting platform and the other side of the adhesive layer attached to at least the portion of the terminal located in the receiving space. The first direction, the second direction, and the thickness direction of the electrochemical device are perpendicular to each other. Using an adhesive terminal arrangement can simplify the terminal installation process, facilitating automated production of the electrochemical device; it can also significantly reduce the terminal size, thereby increasing the energy density of the electrochemical device.

[0018] In some preferred embodiments, along the thickness direction of the electrochemical device, the thickness L of the portion of the electrode in the receiving space satisfies: 0.2 mm ≤ L ≤ 0.7 mm, thereby reducing the size of the electrode in the receiving space and expanding the size of the receiving space.

[0019] In some preferred embodiments, along the thickness direction of the electrochemical device, the thickness L of the portion of the electrode in the receiving space satisfies: 0.2 mm ≤ L ≤ 0.5 mm, thereby further reducing the size of the electrode in the receiving space in the thickness direction and further expanding the size of the receiving space.

[0020] In some preferred embodiments, the thickness H of the shell satisfies: 1 mm ≤ H ≤ 6 mm. By optimizing the thickness of the shell, the thickness of the shell is reduced, thereby increasing the energy density of the electrochemical device.

[0021] In some preferred embodiments, the thickness H of the housing satisfies: 2 mm ≤ H ≤ 4 mm, thereby further reducing the thickness of the housing and further improving the energy density of the electrochemical device.

[0022] In some preferred embodiments, the electrochemical device further comprises a circuit board, which is disposed in the receiving space, so that the receiving space is used to accommodate the circuit board, thereby increasing the volume energy density of the electrochemical device.

[0023] In some preferred embodiments, the thickness of the circuit board along the thickness direction of the electrochemical device is less than or equal to 5 mm. It is understood that by reducing the size of the circuit board in the thickness direction of the electrochemical device, the size of the entire electrochemical device in the thickness direction is reduced.

[0024] In some preferred embodiments, the thickness of the circuit board along the thickness direction of the electrochemical device is less than or equal to 2.7 mm. That is, by further reducing the size of the circuit board in the thickness direction of the electrochemical device, the overall size of the electrochemical device in the thickness direction is further reduced.

[0025] Additional aspects and advantages of the embodiments of the present application will be described, shown, or explained in part in the following description through implementation of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] One or more embodiments are exemplarily described by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, and unless otherwise stated, the dimensions in the drawings do not constitute proportional limitations.

[0027] Figure 1 is a schematic diagram of other embodiments in the art; Figure 2 is a schematic diagram of an electrochemical device provided in one embodiment of the present application; Figure 3 is a partial schematic diagram of an electrochemical device provided in one embodiment of the present application; Figure 4 is a plan view schematic diagram of an electrochemical device provided in one embodiment of the present application; Figure 5 This application provides Figure 4 A-side cross-sectional view; Figure 6 This application provides Figure 5 A magnified view of part B; Figure 7 Another embodiment of the present application provides Figure 5 Enlarged view of part B.

[0028] The reference numerals are as follows: DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0030] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0031] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0032] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0033] The term "perpendicular" is used to describe the ideal state between two components. In actual production or use, there may be a state that is approximately perpendicular between the two components. For example, combined with numerical descriptions, perpendicular can refer to the angle between two straight lines being between 90±10°, perpendicular can also refer to the dihedral angle between two planes being between 90±10°, and perpendicular can also refer to the angle between a straight line and a plane being between 90±10°. The two components described as "perpendicular" may not be absolutely straight lines or planes, but may be roughly straight lines or planes. From a macroscopic perspective, a component can be considered a "straight line" or a "plane" if the overall extension direction is a straight line or a plane.

[0034] The technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0035] As an energy storage device in an electrical device, the size of the electrochemical device 1 is determined by the internal space of the device. Consumer electronics devices, as part of these devices, are often subject to strict controls on size and weight due to portability requirements. Therefore, the electrochemical device 1 needs to be miniaturized and lightweight, while also improving its energy density to extend the device's battery life.

[0036] As one type of electrochemical device 1, steel-cased batteries are preferred energy storage devices in consumer electronic devices due to their high mechanical strength and deformation resistance. In many current designs, the electrochemical device 1 includes a circuit board 600, an electrode assembly 200, a tab 300, and a post 500. The tab 300 of the electrochemical device 1 extends from the electrode assembly 200 and is electrically connected to the post 500. The circuit board 600 is arranged on the outside of the end perpendicular to the thickness direction Z of the electrochemical device 1. However, in this structure, the stacking direction of the circuit board 600 is perpendicular to the thickness direction Z of the electrochemical device 1. Therefore, the width of the circuit board 600 in the thickness direction Z greatly affects the minimum thickness of the electrochemical device 1, which easily makes the purpose of lightweight and thin design difficult.

[0037] Other designs have been proposed, please refer to Figure 1 , the stacking direction of the circuit board 600 is parallel to the thickness direction Z of the electrochemical device 1, thereby reducing the impact of the size of the circuit board 600 on the thickness of the electrochemical device 1. In these designs, the tab 300 extends from the electrode assembly 200 and is connected to the electrode post 500 via ultrasonic welding. However, due to inherent defects in the welding process, this connection method cannot exceed the minimum length limit of the weld mark formed. Within the electrochemical device 1, the connection between the tab 300 and the electrode post 500 requires continuous bending before it can be extended to the external environment. This bending structure not only occupies a large space in the thickness direction Z, but also occupies a large space in the direction in which the tab 300 and electrode post 500 extend, resulting in a significant loss of volumetric energy density in the electrochemical device 1.

[0038] Based on this, the present application provides an electrical device, which includes a functional body and an electrochemical device 1, and the electrochemical device 1 is used to store energy and supply power to the functional body. Electrical devices include but are not limited to consumer electronic devices such as smartphones, smart watches, smart glasses, and AR glasses. Among them, the functional body is the body that realizes the main functions of the electrical device, for example: the main structure composed of electronic devices such as the motherboard and display screen panel in addition to the battery in a smartphone; or the main structure composed of the wristband, display screen panel, and main board in addition to the battery in smart glasses; or the main structure composed of the camera, optical module, main board, sensor, and display module in addition to the battery in AR glasses. As for the electrochemical device 1 provided in this application, please refer to the following for details.

[0039] In the first aspect, please refer to Figures 2 to 5 The present application provides an electrochemical device 1 , which includes a housing 100 and an electrode assembly 200 .

[0040] For more details, please refer to Figures 2 to 5 The housing 100 is provided with a receiving cavity 110 , and the electrode assembly 200 is received in the receiving cavity 110 .

[0041] In some embodiments, please refer to Figure 2 The housing 100 includes a main body 120 and a mounting platform 130 that are connected to each other.

[0042] In some embodiments, please refer to Figure 5 and Figure 6 The receiving chamber 110 is located in the main body 120 , and a receiving chamber 131 is provided in the mounting platform 130 . The receiving chamber 131 is connected to the receiving chamber 110 . Along the thickness direction Z of the electrochemical device 1 , the thickness of the main body 120 is greater than the thickness of the mounting platform 130 .

[0043] In some embodiments, please refer to Figure 5 and Figure 6 The electrochemical device 1 further includes a tab 300 , an adapter 400 and a pole 500 .

[0044] In some embodiments, please refer to Figure 5 and Figure 6 There are multiple tabs 300, and the tabs 300 are gathered along the thickness direction Z to form a multi-tab structure. The multi-tab structure includes a gathering portion 320 and a tab clustering portion 310. The tab clustering portion 310 extends along the first direction X. The tab clustering portion 310 is directly connected to the adapter 400. The adapter 400 extends along the first direction X in the accommodating cavity 131. One end of the pole 500 is connected to the adapter 400, and the other end extends from the accommodating cavity 131 to the mounting platform 130.

[0045] It is necessary to explain that both the first direction X and the second direction Y are perpendicular to the thickness direction Z of the electrochemical device 1 , and the first direction X is perpendicular to the second direction Y. The term "perpendicular" in this application means approximately perpendicular, subject to process tolerances within a range of ±5°; the term "parallel" used hereinafter means approximately parallel, subject to process tolerances within a range of ±5°.

[0046] Furthermore, since it is difficult for the tab 300 to extend completely straight during actual production, in this application, extending along the first direction X means that the entire structure extends approximately along the first direction X.

[0047] It should be noted that “the tab cluster portion 310 is directly connected to the adapter 400” means that the two components are directly connected, and the connection method can be welding, conductive adhesive connection, etc.

[0048] In the above technical solution, the tab 300 and the pole 500 are connected to the adapter 400 , and the tab 300 , the adapter 400 and the pole 500 are stacked in the accommodating cavity 131 and extend out of the mounting platform 130 . Among them, the multi-tab structure is formed by multiple tabs 300 being gathered in the thickness direction and then connected to the adapter 400, wherein the part of the multiple tabs 300 gathered along the thickness direction of the electrochemical device 1 is the gathered portion 320, which is bundled together to form a tab clustering portion 310 after being gathered, and the tab clustering portion 310 is connected to the adapter 400, that is, some of the multiple tabs 300 need to be bent toward the tab 300 on the other side, while the other part of the tabs 300 can be directly extended along the first direction X to the adapter 400, and the gathered portion 320 of the tab 300 forms the tab clustering portion 310 after being bundled, and the tab clustering portion 310 extends along the first direction X and is connected to the adapter 400. The tab 300 is bent only once when folded, and does not need to be bent when connected to the adapter 400, thereby reducing the number of times the tab 300 is bent in the receiving cavity 110 and the accommodating cavity 131, and further reducing the space occupied by the tab 300 inside the housing 100, thereby reducing the thickness of the tab 300 and the pole 500 in the thickness direction Z of the electrochemical device 1, and improving the space utilization of the electrochemical device 1 in the thickness direction Z in terms of both the housing 100 and the electrical connection structure, thereby improving the energy density of the electrochemical device 1.

[0049] In some embodiments, please refer to Figure 6 and Figure 7 , and in conjunction with other figures, the adapter 400 at least partially overlaps the tab clustering portion 310, and a first weld mark area 700 exists in the region where the tab clustering portion 310 and the adapter 400 overlap. It is understood that along the thickness direction Z, the adapter 400 overlaps the tab 300 to utilize the space in the electrochemical device 1 along the thickness direction Z. This structure facilitates the stacking of the electrode assembly 200, allowing the adapter 400 to connect multiple tabs 300 and the electrode assembly 200 along the thickness direction Z, simplifying the integration process of the electrode assembly 200. Combined with the aforementioned extension of the adapter 400 along the first direction X, this planarized surface structure facilitates automated welding of the adapter 400 and the tab 300, eliminating the need for additional processing operations such as flattening the adapter 400 and the tab 300.

[0050] In some embodiments, please refer to Figure 6 and Figure 7In conjunction with other figures, the length D of the first weld mark area 700 in the direction of extension of the adapter 400 satisfies the following relationship: 0.4 mm ≤ D ≤ 0.7 mm. Preferably, the length D of the first weld mark area 700 in the direction of extension of the adapter 400 satisfies the following relationship: 0.4 mm ≤ D ≤ 0.6 mm. This reduces the size of the first weld mark area 700 in the first direction X, thereby providing more space for the tab 300, adapter 400, and electrode 500 in the first direction X. The shortened weld zone eliminates the need for the tab 300 to be tilted relative to the first direction X, reducing bending of the tab 300 within the accommodating cavity 110 or accommodating cavity 131, improving the internal space utilization of the accommodating cavity 131 and accommodating cavity 110, and eliminating the need for the tab 300 to undergo secondary bending to provide more space for the portion with the weld mark, thereby increasing the energy density of the electrochemical device 1.

[0051] Understandably, ultrasonic welding of the tab 300 and the post 500 is currently a common method. However, this process cannot meet the aforementioned dimensional requirements for the first weld mark 700. The minimum size of the ultrasonic welding process is limited by the matching between ultrasonic energy transfer efficiency and process parameters. If the size of the weld area is too small, the welding process requirements become more stringent, and this can easily lead to insufficient local ultrasonic energy and misalignment of equipment parameters such as amplitude and time, resulting in a weak weld.

[0052] Therefore, in some embodiments of the present application, the first weld mark 700 is formed by laser welding the tab 300 and the adapter 400. That is, by utilizing the high energy density beam in the laser welding process to achieve local melting, the size of the first weld mark 700 is precisely limited.

[0053] In some embodiments, the end of the tab clustering portion 310 within the accommodating cavity 131 has a second weld mark area 900. The second weld mark area 900 is formed by melting when the multiple tabs 300 are laser cut. This allows the multiple tabs 300 to form a multi-layer tab 300. The ends of the multi-layer tab 300 can be melted into a whole during laser cutting, so as to facilitate welding the tab 300 to the adapter 400. It should be noted that in some existing technical solutions, ultrasonic welding is often used to weld the tab 300 and the pole 500, and the weld mark size formed is relatively large. The specific reasons can be found above. When the multi-layer tab 300 is clustered, all the tabs 300 are laser cut away from the end of the electrode assembly 200, thereby forming a high-temperature melting zone under the laser beam, and the second weld mark area 900 is formed by the melting zone. The clustered and laser-cut tabs 300 are then laser welded to the adapter 400. Since laser welding requires all the tabs 300 to be fitted together, the folded tabs 300 may not be able to fit completely together, otherwise a technical problem of explosion points will occur. Therefore, laser cutting is used to form a welding area at the end, which is the second weld print area 900, to achieve welding and fixation of multiple tabs 300. On the other hand, after the multi-layer tabs 300 are welded and fixed, it is more convenient to weld the tabs 300 to the adapter.

[0054] In some embodiments, the first weld mark 700 is formed by laser welding the adapter 400 and at least two layers of the tabs 300. Welding two or more layers of the tabs 300 makes the entire structure more stable.

[0055] Furthermore, along the first direction X, the multiple tabs 300 are aligned at the end of the tab clustering portion 310 away from the electrode assembly 200. This improves the connection strength between the multiple tabs 300 and the welding strength between the tab clustering portion 310 and the adapter 400. In conjunction with the above description of the second weld mark area 900, after the multiple tabs 300 are gathered together, a laser welding process is used to form the tab clustering portion 310. The tab clustering portion 310 is away from the end of the electrode assembly 200. When the ends are aligned, the welding here is burr-free, which increases the welding strength, reduces thermal effects, and improves the electrical performance of the tabs 300.

[0056] Furthermore, the tab clustering portion 310 extends along the first direction X. Therefore, in the thickness direction Z, at least part of the tabs 300 still need to be bent to be connected to another part of the tabs 300 to form the tab clustering portion 310. The tabs 300 located near the outside of the multi-layer tabs 300 need to be welded to the adapter 400. When the welding strength is insufficient, the welding strength can be improved by increasing the number of tabs 300 layers that need to be welded.

[0057] In some embodiments, please refer to Figure 6 and Figure 7, and in combination with other drawings, the electrode assembly 200 includes a plurality of electrode pieces 210 .

[0058] In some embodiments, please refer to Figure 6 and Figure 7 , and in conjunction with other figures, multiple electrode pieces 210 are stacked within the receiving cavity 110, and a tab 300 is connected to a electrode piece 210. The multiple electrode pieces 300 are gathered together in the same adapter 400 and bent relative to the tabs 300 that are farther away from the adapter 400 along the thickness direction Z. That is, in the thickness direction Z, multiple electrode pieces 210 are stacked, and each electrode piece 210 is connected to a tab 300. Because the tabs 300 need to be gathered together to form a tab cluster 310, the tabs 300 that are farther away from the adapter 400 in the thickness direction Z need to be bent closer to the adapter 400, thereby forming the tab cluster 310. After being gathered together, these tabs 300 are connected to the adapter 400 along the first direction X. That is, the tabs 300 provided in this application can be connected to the adapter 400 by being bent at most once. This reduces the number of bends of the tab 300 and the number of tabs 300 that need to be bent, fully utilizing the space in the thickness direction Z of the electrochemical device 1 to connect the tab 300, the adapter 400 and the pole, thereby improving the energy density of the electrochemical device 1.

[0059] In some embodiments, please refer to Figure 6 , and in conjunction with other figures, along the thickness direction Z of the electrochemical device 1, the tab 300 and the post 500 are disposed on opposite sides of the adapter 400. It should be understood that "opposite sides" means that the adapter 400 has two opposing sides in the thickness direction Z, with the tab 300 connected to one side of the adapter 400 and the post 500 connected to the other side of the adapter 400, and the area where the post 500 connects to the adapter 400 is at least partially offset from the first weld mark 700. Preferably, the post 500 extends from the adapter 400 along the thickness direction Z out of the accommodating cavity without any bends, while the tab 300 is disposed on the other side of the adapter 400. This fully utilizes the space on both sides of the adapter 400, allowing the tab 300 and post 500 to connect to the adapter 400 over a larger area, thereby improving the connection strength and enhancing the performance and life of the electrochemical device 1.

[0060] In some embodiments, please refer to Figure 7, and in conjunction with other figures, along the thickness direction Z of the electrochemical device 1, the tab 300 and the post 500 are arranged on the same side of the adapter 400. It can be understood that "same side" means that the adapter 400 has two opposing sides in the thickness direction Z, and the tab 300 and the post 500 are both connected to the same side of the adapter 400 in the thickness direction. Because the post 500 also has a partial structure within the accommodating cavity 131, there is a gap between the connection between the post 500 and the adapter 400 and the surface of the mounting platform 130 in the thickness direction Z. Therefore, by utilizing this gap to arrange the tab 300, the thickness of the electrochemical device 1 is reduced. Through the above structure, the internal space utilization of the electrochemical device 1 is improved, thereby increasing the energy density of the electrochemical device 1.

[0061] For further information, please refer to Figure 7 In conjunction with other figures, along the thickness direction Z of the electrochemical device 1, the sum of the thickness of the adapter 400 and the thickness of the tab cluster 310 is less than the thickness of the electrode 500 within the accommodating cavity 131. In other words, by further utilizing the internal space of the accommodating cavity 131, the tab cluster 310 can be accommodated between the adapter 400 and the mounting platform 130.

[0062] In some embodiments, please refer to Figure 6 and Figure 7 , and in conjunction with other figures, along the second direction Y, a side surface of the main body 120 adjacent to the mounting platform 130 and a portion of the outer surface of the mounting platform 130 together form a receiving space 140, which is used to receive the circuit board 600. It will be understood that the receiving space 140 formed by the side surface of the main body 120 and the outer surface of the mounting platform 130 can be used to receive the circuit board 600, thereby fully utilizing the thickness difference between the mounting platform 130 and the main body 120 to receive the circuit board 600.

[0063] In some embodiments, please refer to Figure 6 and Figure 7 , and in combination with other drawings, the mounting platform 130 is provided with an opening 132 , and the pole 500 extends from the accommodating cavity 131 through the opening 132 .

[0064] In some embodiments, please refer to Figure 6 and Figure 7 , and in combination with other drawings, the electrochemical device 1 also includes an adhesive layer 800, which is attached around the opening 132, one side of the adhesive layer 800 is attached to the outer surface of the mounting platform 130, and the other side of the adhesive layer 800 is attached to at least a portion of the pole 500 located in the receiving space 140.

[0065] It is understood that the terminal 500 is bonded to the opening 132 via the adhesive layer 800. Specifically, the terminal 500 is divided by the opening 132 into a portion within the accommodating cavity 131 (hereinafter referred to as the "inner height of the terminal 500") and another portion of the terminal 500 located within the receiving space 140 (hereinafter referred to as the "outer height of the terminal 500"). The adhesive process used to attach the terminal 500 to the mounting platform 130 reduces the outer height of the terminal 500, thereby reducing the space occupied by the terminal 500 within the receiving space 140. Furthermore, the adhesive process can be cured at room temperature or low temperature, reducing the thermal impact on the electrochemical device 1. Furthermore, the adhesive process facilitates automated production, thereby improving production line efficiency. The primary materials of the adhesive layer 800 include, but are not limited to, epoxy resin, silicone rubber, and the like.

[0066] Still need to add is, please review Figure 4 In conjunction with other figures, the main body 120 of the housing 100 is in the shape of a rectangular parallelepiped. The length and width directions of the main body 120 are both perpendicular to the thickness direction Z of the main body 120. The first direction X is in the same direction as the length direction of the main body 120, and the second direction Y is in the same direction as the width direction of the main body 120. The mounting platform 130 is disposed on a side surface of the main body 120. The widths of the main body 120 and the mounting platform 130 in the second direction Y are substantially the same. The mounting platform 130 is disposed protruding from the main body 120 along the first direction X, thereby causing the accommodating space 140 to be recessed relative to the main body 120. This reduces the height of the circuit board functional assembly 600 protruding relative to the main body 120 in the thickness direction Z, thereby facilitating the installation of the circuit board functional assembly 600 on the main body 120 and facilitating the installation of the electrochemical device 1 on an electrical device.

[0067] Optionally, the mounting platform 130 is arranged on a side surface in the length direction of the main body 120, and the electrode assembly 200 is wound and its stacking direction is in the same direction as the thickness direction Z of the electrochemical device 1, thereby increasing the energy density and capacity of the electrode assembly 200, reducing the internal resistance of the electrode assembly 200, and improving the heat dissipation performance; the stacking direction of the circuit board 600 is in the same direction as the thickness direction Z of the electrochemical device 1, thereby reducing the limitation of the width of the circuit board 600 on the thickness of the electrochemical device 1, and, in the thickness direction Z, by utilizing the receiving space 140 between the mounting platform 130 and the main body 120, it is convenient to install and arrange the circuit board 600, thereby improving the energy density of the electrochemical device 1.

[0068] In some embodiments, please refer to Figure 6 and Figure 7, and in conjunction with other figures, along the thickness direction Z of the electrochemical device 1 , the thickness L of the portion of the electrode 500 within the receiving space 140 satisfies the following: 0.2 mm ≤ L ≤ 0.7 mm. That is, the outer height of the electrode 500 is between 0.2 mm and 0.7 mm. When the outer height of the electrode 500 is less than 0.2 mm, current transmission is easily affected, thereby affecting the electrical performance of the electrochemical device 1 . When the outer height of the electrode 500 is greater than 0.7 mm, the electrode 500 occupies a large space within the receiving space 140 , which can easily lead to wasted space and reduced energy density.

[0069] Preferably, along the thickness direction Z of the electrochemical device 1 , the thickness L of the portion of the electrode 500 within the receiving space 140 satisfies the following relationship: 0.2 mm ≤ L ≤ 0.5 mm. This further reduces the space occupied by the electrode 500 within the receiving space 140 , improves structural compactness, and reduces energy density loss.

[0070] In some embodiments, the electrochemical device 1 further includes a circuit board 600 , which is disposed in the receiving space 140 . This fully utilizes the receiving space 140 to accommodate the circuit board 600 , making the structure of the electrochemical device 1 more compact and thereby increasing the volume energy density of the electrochemical device 1 .

[0071] In some embodiments, the thickness of the circuit board 600 along the thickness direction Z of the electrochemical device 1 is less than or equal to 5 mm. Preferably, the thickness of the circuit board 600 along the thickness direction Z of the electrochemical device 1 is less than or equal to 2.7 mm. By reducing the thickness of the circuit board 600, the overall volume of the electrochemical device 1 is reduced, thereby increasing the energy density. The reduced thickness of the circuit board 600 also facilitates the installation of the electrochemical device 1 within electrical equipment.

[0072] In some embodiments, please refer to Figure 6 and Figure 7 , and in conjunction with other figures, the thickness H of the housing 100 satisfies 1mm≤H≤6mm. Preferably, the thickness H of the housing 100 satisfies 2mm≤H≤4mm. This facilitates the manufacture of an ultra-thin battery cell, making it suitable for the above-mentioned electrical equipment.

[0073] In combination with one or more of the above embodiments, the present application further provides the following test to test the electrochemical device 1 and its structure.

[0074] Test method: Providing a plurality of electrochemical devices 1; A plurality of adapters 400 and tabs 300 in electrochemical devices 1 are provided, each having a first weld mark 700 formed by laser welding. The adapters 400 and tabs 300 are classified into Embodiments 1, 2, 3, and 4 formed by an anode laser welding process, and Embodiments 5, 6, 7, and 8 formed by a cathode laser welding process. Cut the first weld print area 700 into multiple strip samples with a length of 1.5 mm; Place the cut first weld print area 700 into a tensile testing machine; A tensile testing machine is used to clamp at least two sides of the first weld print area 700; Keep both sides on the same side; Operate the tensile testing machine for testing; Pull the sample until the first weld print area 700 is pulled apart; Record the tensile force when the first weld print area 700 is pulled apart, in N.

[0075] Combined with the above test method, a stress test is performed on the first weld print area 700; Example group: Example 1: The length of the first weld mark area 700 in the extending direction of the adapter 400 is 0.4 mm.

[0076] Example 2: The length of the first weld mark area 700 in the extending direction of the adapter 400 is 0.5 mm.

[0077] Example 3: The length of the first weld mark area 700 in the extending direction of the adapter 400 is 0.6 mm.

[0078] Example 4: The length of the first weld mark area 700 in the extending direction of the adapter 400 is 0.7 mm.

[0079] Example 5: The length of the first weld mark area 700 in the extending direction of the adapter 400 is 0.4 mm.

[0080] Example 6: The length of the first weld mark area 700 in the extending direction of the adapter 400 is 0.5 mm.

[0081] Example 7: The length of the first weld mark area 700 in the extending direction of the adapter 400 is 0.6 mm.

[0082] Example 8: The length of the first weld mark area 700 in the extending direction of the adapter 400 is 0.7 mm.

[0083] The results of anodic laser welding are shown in the following table, Table 1:

[0084] The cathode laser welding results are shown in the following table, Table 2:

[0085] In conjunction with Tables 1 and 2 above, the present application welds the adapter 400 and the tab 300 using anodic laser welding and cathode laser welding processes, respectively. Based on the weld mark strength formed by ultrasonic welding in actual production, when the weld mark strength formed by anodic ultrasonic welding is less than 7N, the weld mark strength is insufficient; when the weld mark formed by cathode ultrasonic welding is less than 2N, the weld mark strength is insufficient. In Comparative Example 1, when the length of the first weld mark area 700 is 0.3mm, it can withstand a tensile force of 6.5N. In Comparative Example 2, when the length of the first weld mark area 700 is 0.3mm, it can withstand a tensile force of 1.7N. Therefore, Comparative Examples 1 and 2 demonstrate that although laser welding can achieve a smaller first weld mark area 700, it is unusable due to insufficient weld mark strength. Combining Examples 1 and 5, it can be concluded that the first weld mark area 700 in this case can meet the required welding strength requirements. That is, the minimum length of the first weld mark area is 0.4mm.

[0086] Furthermore, the minimum size of the weld mark formed by the ultrasonic welding process is 0.8 mm. If the length of the first weld mark area 700 is greater than or equal to 0.8 mm, a secondary bend is required to accommodate the tab 300 and the adapter 400 in the receiving cavity 110. Therefore, the length of the first weld mark area is less than 0.8 mm. If the length is too long, it is also easy to waste energy density. Therefore, preferably, when the length of the first weld mark area is between 0.4 mm and 0.6 mm, and can be equal to 0.4 mm and 0.6 mm respectively, a better embodiment can be obtained. Specific test results can be combined with Examples 1 to 3, and Examples 5 to 7.

[0087] In addition, the energy density improvement benefit of the electrochemical device 1 is calculated by combining one or more of the embodiments of the present application. In some conventional design methods, the structure of the tab 300 being bent twice and the structure of the ultrasonic welding process being used as the welding method is used as a comparative example, see Figure 1 . In the direction perpendicular to the thickness direction Z of the comparative example, the sum of the width of the circuit board 600 and the outer height of the pole 500 in the comparative example is 2.5 mm, the wall thickness of its housing 100 is 0.2 mm, and the distance of the gap between its pole piece 210 and the side wall of the housing 100 is 2.7 mm, so that, in this direction, the total length K' from the pole piece 210 to the edge of the electrochemical device 1 is 5.4 mm. In the above calculation, "the distance of the gap between the pole piece 210 and the side wall of the housing 100" means that the welding structure formed by the ultrasonic welding process needs to be accommodated in the gap, that is, the length of the gap can directly reflect the space occupied by the welding structure formed by the ultrasonic welding process in the actual structure.

[0088] In the embodiment of the present application, in the first direction X, the distance between the electrode piece 210 and the edge of the mounting platform 130 on the side closest to the main body 120 is 2.8 mm. The wall thickness of the housing 100 is 0.2 mm, and the width of the mounting platform 130 is 1.0 mm. Therefore, the total length K from the electrode piece 210 to the edge of the electrochemical device 1 provided by the embodiment of the present application is 4 mm.

[0089] Combining the calculation results of the above comparative example and the embodiment of the present application, it can be obtained that the technical solution provided by the present application can obtain a space gain of 1.4 mm in the first direction X.

[0090] In some other embodiments, the width of the circuit board 600 can be reduced to 2.2 mm after optimization design. Combined with the above calculation, it can be obtained that the technical solution provided in the embodiment of the present application can obtain a space gain of 0.8 mm.

[0091] Therefore, the technical solution provided by the present application can obtain a higher space benefit without investing a lot of R&D costs in the structure of the circuit board 600. That is, in some demands, the R&D cost for reducing the overall volume of the circuit board 600 is high, so more demands use common circuit boards 600, and these circuit boards 600 are larger in size. In combination with the technical solution provided by the present application, since the laser welding process between the tab 300 and the adapter 400 is adopted in the present application, a smaller first weld print area 700 is obtained, thereby saving the internal space of the accommodating cavity 110, so that the partial connection portion 230 extending from the pole piece 210 is directly connected to the connection end 210 and the tab 300 along the first direction X, thereby reducing the occupied space of the accommodating cavity 110 and reducing the size of the electrochemical device 1 in the first direction X; and in the thickness direction Z, the present application In the provided embodiment, the electrode post 500 is adhesively bonded, and the electrode piece 210 and the electrode post 500 are welded to the adapter 400. By utilizing the size of the electrode post 500 within the accommodating cavity 131 to accommodate the electrode tab 300, the size of the mounting platform 130 in the thickness direction Z is reduced, thereby providing a receiving space 140 for the circuit board 600. Furthermore, the electrode tab 300 and the electrode post 500 are disposed on the side of the adapter 400 near the opening 132, further reducing the size in the thickness direction Z. In other words, the present application provides more space in the receiving space 140 in the first direction X through the laser welding process, and provides more space in the thickness direction Z through the adhesive bonding process, thereby improving the energy density of the electrochemical device 1. On the other hand, the increased receiving space 140 can accommodate a larger circuit board 600, reducing the cost of miniaturizing the circuit board 600 and simplifying the process requirements.

[0092] The present application provides an electrochemical device 1, which includes a housing 100, an electrode assembly 200, a tab 300, an adapter 400, and a post 500. The housing 100 is provided with a receiving cavity 110 for receiving the electrode assembly 200, wherein the housing 100 further includes a main body 120 and a mounting platform 130 that are connected to each other. The receiving cavity 110 is located in the main body 120, and a receiving cavity 131 is provided in the mounting platform 130. The receiving cavity 131 is connected to the receiving cavity 110. Along the thickness direction Z of the electrochemical device 1, the thickness of the main body 120 is greater than the thickness of the mounting platform 130. Multiple tabs 300 are gathered together along the thickness direction to form a multi-tab structure. The multi-tab structure includes a gathering portion 320 and a tab clustering portion 310. The tab clustering portion 310 extends along a first direction X and is directly connected to the adapter 400. The adapter 400 extends along the first direction X within the accommodating cavity 131. One end of the terminal 500 is connected to the adapter 400, and the other end extends from the accommodating cavity 131 to the mounting platform 130. The first direction X is perpendicular to the thickness direction of the electrochemical device 1. Through the above structure, the tab 300 is bent only once when folded, and does not need to be bent when connected to the adapter 400, thereby reducing the number of times the tab 300 is bent in the receiving cavity 110 and the accommodating cavity 131, thereby reducing the space occupied by the tab 300 inside the shell 100, thereby reducing the thickness of the tab 300 and the pole 500 in the thickness direction Z of the electrochemical device 1, and improving the space utilization of the electrochemical device 1 in the thickness direction Z in terms of both the shell 100 and the electrical connection structure, thereby improving the energy density of the electrochemical device 1.

[0093] Based on the same inventive concept, the present application also provides an electrical device comprising the electrochemical device 1 described above. The structure and function of the electrochemical device 1 can be found above and will not be further described here. Therefore, the electrical device provided by the present application can also improve the current design status of steel-cased battery structures, reducing the waste of size and energy density caused by multiple bending of the tabs.

[0094] It should be noted that the preferred embodiments of the present application are given in the specification and drawings of this application. However, the present application can be implemented in many different forms and is not limited to the embodiments described in this specification. These embodiments are not intended to be additional limitations on the content of this application. The purpose of providing these embodiments is to make the understanding of the disclosure of this application more thorough and comprehensive. In addition, the above-mentioned technical features can be combined with each other to form various embodiments not listed above, which are all considered to be within the scope of the description of this application; further, it is obvious to those skilled in the art that improvements or changes can be made based on the above description, and all such improvements and changes should fall within the scope of protection of the claims attached to this application.

Claims

1. An electrochemical device comprising a housing and an electrode assembly, wherein the housing is provided with a receiving cavity, and the electrode assembly is received in the receiving cavity, characterized in that: The housing comprises: a main body and a mounting platform that are connected to each other, the receiving cavity is located in the main body, the mounting platform is provided with a receiving cavity, the receiving cavity is connected to the receiving cavity, and along the thickness direction of the electrochemical device, the thickness of the main body is greater than the thickness of the mounting platform; The electrochemical device further includes a plurality of tabs, an adapter, and a pole post. The plurality of tabs are gathered along the thickness direction to form a multi-tab structure. The multi-tab structure includes a gathering portion and a tab clustering portion. The tab clustering portion extends along a first direction and is directly connected to the adapter. The adapter extends along the first direction within the accommodating cavity. One end of the pole post is connected to the adapter, and the other end extends from the accommodating cavity to the mounting platform. The first direction is perpendicular to a thickness direction of the electrochemical device.

2. The electrochemical device according to claim 1, wherein The adapter and the tab cluster portion at least partially overlap, and a first weld mark area exists in the area where the tab and the adapter overlap, and a length D of the first weld mark area in the extending direction of the adapter satisfies: 0.4mm≤D≤0.7mm.

3. The electrochemical device according to claim 2, characterized in that 0.4mm≤D≤0.6mm.

4. The electrochemical device according to claim 2, wherein The first weld mark area is formed by a laser welding process between the tab and the adapter.

5. The electrochemical device according to claim 4, characterized in that The first weld mark is formed by laser welding the adapter and at least two layers of the tab.

6. The electrochemical device according to claim 1, wherein The end portion of the tab clustering portion in the accommodating cavity has a second weld print area, and the second weld print area is formed by melting when the plurality of tabs are cut by laser.

7. The electrochemical device according to claim 6, characterized in that Along the first direction, the plurality of tabs are aligned at an end of the tab clustering portion away from the electrode assembly.

8. The electrochemical device according to claim 7, characterized in that Along the thickness direction of the electrochemical device, the tab clustering portion and the pole are arranged on different sides of the adapter.

9. The electrochemical device according to claim 7, characterized in that Along the thickness direction of the electrochemical device, the tab clustering portion and the pole are arranged on the same side of the adapter.

10. The electrochemical device according to claim 9, characterized in that Along the thickness direction of the electrochemical device, the sum of the thickness of the adapter and the thickness of the tab clustering portion is less than the thickness of the pole in the accommodating cavity.

11. The electrochemical device according to claim 1, wherein Along the second direction, a side surface of the main body close to the mounting platform and a portion of the outer surface of the mounting platform jointly form a receiving space, the mounting platform is provided with an opening, and the pole extends from the receiving cavity through the opening; The electrochemical device also includes an adhesive layer, which is attached around the opening, one side of the adhesive layer is attached to the outer surface of the mounting platform, and the other side of the adhesive layer is attached to at least a portion of the pole located in the receiving space, and the first direction, the second direction and the thickness direction of the electrochemical device are perpendicular to each other.

12. The electrochemical device according to claim 11, characterized in that Along the thickness direction of the electrochemical device, a thickness L of a portion of the electrode in the receiving space satisfies: 0.2 mm ≤ L ≤ 0.7 mm.

13. The electrochemical device according to claim 12, wherein: Along the thickness direction of the electrochemical device, a thickness L of a portion of the electrode in the receiving space satisfies: 0.2 mm ≤ L ≤ 0.5 mm.

14. The electrochemical device according to claim 1, wherein The thickness H of the shell satisfies: 1mm≤H≤6mm.

15. The electrochemical device according to claim 14, characterized in that The thickness H of the shell satisfies: 2mm≤H≤4mm.

16. The electrochemical device according to any one of claims 11 to 15, characterized in that: The electrochemical device further includes a circuit board, which is disposed in the receiving space.

17. The electrochemical device according to claim 16, characterized in that Along the thickness direction of the electrochemical device, the thickness of the circuit board is less than or equal to 5 mm.

18. The electrochemical device according to claim 17, characterized in that Along the thickness direction of the electrochemical device, the thickness of the circuit board is less than or equal to 2.7 mm.

19. An electrical device, characterized in that: Comprising the electrochemical device according to any one of claims 1-18.

20. A method for manufacturing the electrochemical device according to any one of claims 1 to 18, characterized in that: Leading the tab out of the electrode assembly; Cutting and melting the end of the electrode tab away from the electrode assembly by laser to form a second weld print area; The outer layer of the multiple layer of tabs is laser welded to the adapter, and at least a portion of the outer layer of tabs is bent.

21. The method according to claim 20, characterized in that Laser welding the outer layer of the multiple layers of the pole tabs to the adapter includes: laser welding the multiple layers of the pole tabs to the adapter.

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