Electrochemical device and electronic equipment

Abstract

The utility model discloses an electrochemical device and electronic equipment, including electrode subassembly, including electrode main part and the first pole lug and the second pole lug of its same side extension, pole post subassembly is used for leading out the polarity of electrode main part, lower casing includes first casing and second casing and both connections form the step of intercommunication, wherein first casing is used for placing electrode main part, and second casing is used for placing pole lug, electrolyte and pole post subassembly, casing insulating part and pole post insulating part, and the connecting portion of pole lug and electrode main part is located at the step, upper cover plate is used for with lower casing connects and forms sealed structure, casing insulating part and pole post insulating part are located between pole post subassembly and lower casing, are used for the insulation of pole post subassembly and lower casing, the utility model discloses can effectively avoid the fatigue fracture of pole lug bending, and the step structure of setting reduces the heat of bending, improves energy density simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to an electrochemical device and electronic equipment. Background Technology

[0002] With the advancement of technology and the advent of the intelligent wave, people's requirements for the energy density of electronic devices are constantly increasing. However, the internal space of electronic devices is limited, and its compression has almost reached its limit. There is an urgent need to develop new structures to accommodate more capacity within a limited space. In addition, the bare cells of conventional hard-shell batteries usually need to be welded to tabs with slightly greater rigidity and then bent before being welded to the casing to bring out the positive and negative electrodes. The tab connection welding and bending occupy a lot of space in the hard-shell battery casing, resulting in low energy density. Furthermore, when conventional cells are inserted into the casing, they are inserted from the side with the smaller area, making insertion difficult and the cells susceptible to damage and scratches. Utility Model Content

[0003] This invention addresses the problems in the prior art by disclosing an electrochemical device and electronic device. The device of this invention forms two shells with a step at the connection between them. One shell houses the electrode body, and the other shell houses the electrolyte, tabs, electrode post assembly, shell insulation, and electrode post insulation. The connection between the tabs and the electrode body is located at the step, which improves the overall electrolyte retention and energy density of the battery. In addition, this structure allows the battery cell to enter the shell without damage.

[0004] This utility model is achieved through the following technical solution:

[0005] This invention first provides an electrochemical device, characterized in that it includes:

[0006] An electrode assembly includes an electrode body and a first electrode tab and a second electrode tab extending from the same side thereon;

[0007] The electrode assembly is used to draw out the polarity of the electrode body;

[0008] The lower housing includes a first housing and a second housing that are interconnected and form a step at their connection. The first housing is used to place the electrode body, and the second housing is used to place the tabs, electrolyte and electrode post assembly, housing insulation and electrode post insulation. The connection between the tabs and the electrode body is located at the step.

[0009] The upper cover plate is used to form a sealed structure when connected to the lower housing;

[0010] The housing insulation and the pole insulation are located between the upper cover and the lower housing, and are used to insulate the pole lugs from the lower housing.

[0011] As a further option, the wall thickness of the lower shell is 0.05mm to 0.2mm.

[0012] As a further embodiment, the first housing is a rectangular housing, formed by a first surface and a second, third, fifth, and fourth surface connected vertically above it in sequence. The second housing is formed by a seventh surface and an eighth, sixth, and ninth surface connected vertically above it in sequence. The third and eighth surfaces are coplanar, the fourth and ninth surfaces are on the same plane, and the fifth and seventh surfaces are vertically connected to form a step. The seventh surface is provided with a through hole for assembling the pole assembly and an injection hole for injecting liquid.

[0013] As a further embodiment, the length of the first shell is A1, the length of the second shell is A2, and the condition 0.01≤A2 / A1≤0.4 is met; the height of the first shell is B1, the length of the second shell is B2, and the condition 0.01≤B2 / B1≤0.7 is met.

[0014] As a further embodiment, the housing insulation component is an L-shaped integral structure, including a first insulating part and a second insulating part that are perpendicular to each other. The first insulating part is arranged parallel to the second tab and is pasted or coated on the upper cover plate. The second insulating part is arranged perpendicular to the second tab and is pasted or coated on the sixth surface. The material of the housing insulation component is a rigid insulating colloid, insulating paper, or insulating coating.

[0015] As a further embodiment, the electrode assembly includes an upper electrode portion and a lower electrode portion fixedly connected below it. The lower electrode portion has a rectangular structure, and the upper electrode portion has a cylindrical structure. The lower electrode portion is disposed inside the second housing and fixedly connected to the second electrode tab. The upper electrode portion passes through a through hole on the seventh surface and is connected to an external circuit board to conduct electricity to the electrochemical device.

[0016] As a further embodiment, the pole insulation component is L-shaped, including a first insulating pad and a second insulating pad that are perpendicular to each other, and the first insulating pad is provided with an insulating protrusion for passing through the upper part of the pole.

[0017] As a further embodiment, the second tab extends from the electrode body. If the electrode body is a wound structure, the second tab is directly welded or abutted to the lower part of the electrode post, and the first tab is directly welded or abutted to the lower shell. If the electrode body is a laminated structure, the second tab is pre-welded with ultrasonic waves before being welded or abutted to the lower part of the electrode post, and the first tab is pre-welded with ultrasonic waves before being welded or abutted to the lower shell. The second tab is parallel to the lower part of the electrode post.

[0018] As a further option, the welding point between the pole assembly and the lower housing is located inside the second housing.

[0019] This invention also provides an electronic device, which includes the aforementioned electrochemical device.

[0020] The features and beneficial effects of this utility model are as follows:

[0021] (1) The structure of the lower shell and electrode assembly provided in this application effectively avoids fatigue fracture when the tab is bent, eliminates the tab transfer welding and bending process, improves battery reliability, increases production efficiency and reduces production costs; the stepped structure reduces heat at the bending point, and the internal structure of the second shell increases the battery liquid retention, greatly improving the battery cycle performance; at the same time, it increases the energy density.

[0022] (2) The double-shell structure of this utility model allows the battery cell to be inserted from the side with the largest area when it is inserted into the shell, which solves the problems of conventional batteries being difficult to insert into the shell and the battery cell being easily scratched when it is inserted into the shell.

[0023] (3) The ratio of the height of the first shell and the height of the second shell in this utility model can increase the space of the second shell and improve the energy density of the cavity. This prevents the tabs from being too thick and affecting the welding of the lower shell and the upper cover, thus reducing the welding yield. It also leaves enough space for setting the electrode assembly, which helps to reduce the difficulty of battery preparation and improve the preparation efficiency. It also allows the second shell to hold more electrolyte, which helps to improve the battery cycle performance. At the same time, it does not affect the layout of the circuit board.

[0024] (4) The bare cell of this utility model does not need to be welded or bent with other tabs. It can be directly led out from the electrode body and welded or abutted to the electrode assembly or the shell. Furthermore, the second shell can reserve enough space in height to install the circuit board. Therefore, the tabs do not occupy the internal space of the shell, which greatly improves the capacity of the battery from the structural design. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is an exploded view of the electrochemical device described in an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the lower housing as described in an embodiment of the present utility model;

[0028] Figure 3 This is a schematic diagram of the electrode assembly described in an embodiment of the present utility model;

[0029] Figure 4This is a side view of the lower housing as described in an embodiment of the present utility model;

[0030] Figure 5 This is a schematic diagram of the housing insulation component described in an embodiment of the present utility model;

[0031] Figure 6 This is a schematic diagram of the pole assembly described in an embodiment of the present utility model;

[0032] Figure 7 This is a schematic diagram of the pole insulating component described in an embodiment of the present utility model;

[0033] Figure 8 This is a top view of the electrochemical device described in an embodiment of the present invention;

[0034] Figure 9 for Figure 8 Sectional view of AA;

[0035] Figure 10 for Figure 8 A cross-sectional view of an embodiment of the housing insulation component by AA;

[0036] Figure 11 for Figure 8 A cross-sectional view of AA regarding another embodiment of the housing insulation component;

[0037] Figure 12 for Figure 8 A cross-sectional view of AA regarding another embodiment of the housing insulation component;

[0038] Figure 13 for Figure 8 Sectional view of CC;

[0039] Figure 14 for Figure 8 Cross-sectional view of BB regarding Example 1;

[0040] Figure 15 for Figure 8 Cross-sectional view of Example 2 from BB;

[0041] Figure 16 for Figure 8 Cross-sectional view of Example 3 from BB;

[0042] Figure 17 for Figure 8 Cross-sectional view of Example 4 from BB;

[0043] Figure 18 for Figure 8 Cross-section of Example 5 by BB Figure 1 ;

[0044] Figure 19for Figure 8 Cross-section of Example 4 by BB Figure 2 ;

[0045] Figure 20 for Figure 8 Cross-section of Example 3 by BB Figure 3 ;

[0046] Figure 21 This is a schematic diagram of the lower housing as described in an embodiment of the present utility model;

[0047] Figure 22 This is a schematic diagram showing the connection between the lower housing and the upper cover plate according to an embodiment of the present utility model;

[0048] Figure 23 This is a schematic diagram illustrating the connection between the lower housing and the circuit board according to an embodiment of the present invention. Figure 1 ;

[0049] Figure 24 This is a schematic diagram illustrating the connection between the lower housing and the circuit board according to an embodiment of the present invention. Figure 2 .

[0050] Explanation of reference numerals in the attached figures:

[0051] 1-Lower housing; 11-First housing; 111-First surface; 112-Second surface; 113-Third surface; 114-Fourth surface; 115-Fifth surface; 12-Second housing; 121-Sixth surface; 122-Seventh surface; 123-Eighth surface; 124-Ninth surface; 125-Through hole; 126-Injection hole; 13-First positioning surface; 14-Second positioning surface; 2-Electrode assembly; 21-Electrode body; 22-First electrode tab; 23-Second electrode tab; 3-Upper cover plate; 31-First limiting surface; 32-Second limiting surface; 4-Housing insulation component; 5-Electrode post insulation component; 51-First insulating gasket; 52-Insulating protrusion; 53-Second insulating gasket; 6-Circuit board; 7-Electrode post assembly; 71-Upper part of electrode post; 72-Lower part of electrode post; 8-Metal strip; 9-Head protective adhesive. Detailed Implementation

[0052] To facilitate understanding of this utility model, a more comprehensive description of this utility model will be provided below, along with embodiments of this utility model, but this does not limit the scope of this utility model.

[0053] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0054] Some existing battery casings are also designed with a dual-cavity structure. When the battery body is located in one of the cavities, the tabs need to be welded inside the cavity and then bent 180°. Since the connection between the tabs and the battery body is a weak point, bending the tabs 180° can easily cause fatigue fracture. When the tabs are welded inside the cavity and then bent, the cavity also needs to accommodate the tab adapter, the tab bending, and the terminal assembly, wasting a lot of space and thus reducing the overall energy density. In addition, during charging and discharging, current flows through the tabs, and the heat at the tabs is significantly concentrated. The bending at this point makes the heat even more concentrated, making thermal failure more likely and greatly increasing the probability of battery thermal failure. To solve the above problems, avoid fatigue fracture during tab bending, reduce heat at the bending point, and make full use of the internal space of the cavity to improve energy density, this application proposes an electrochemical device. It should be noted that in the embodiments of this application, the electrochemical device is the smallest unit that makes up the battery or battery module, and is the place where electrical energy and chemical energy are converted.

[0055] An electrochemical device, such as Figures 1 to 24 As shown, it includes a lower housing 1, an electrode assembly 2, an upper cover plate 3, a housing insulator 4, an electrode post insulator 5, and an electrode post assembly 7.

[0056] Electrode assembly 2 includes electrode body 21, first electrode tab 22, and second electrode tab.

[0057] The lower housing 1 has a dual-cavity structure, with a step forming at the connection between the two cavities. One cavity is used to house the electrode body 21, and the other cavity is used to house the tabs, electrolyte, and electrode post assembly. The connection between the tabs and the electrode body is located at the step.

[0058] The upper cover plate 1 is used to form a sealing structure after being fixedly connected with the lower housing 1;

[0059] Housing insulation 4 is used to insulate the electrode assembly from the lower housing;

[0060] The electrode post insulator 5, located between the electrode post assembly 7 and the lower housing 1, is used to insulate the electrode post assembly 7 and the lower housing 1.

[0061] The electrode assembly 7 is used to draw out the polarity of the electrode body and conduct the electrochemical device.

[0062] Both the lower housing 1 and the upper cover plate 3 are integrally formed by stamping metal sheets to create a sealed cavity. The thickness of the metal sheet used to manufacture the lower housing 1 is set to 0.05mm to 0.2mm. If the thickness is less than 0.05mm, it will cause breakage at the corners during stamping, resulting in insufficient structural strength of the housing. This will prevent the effective suppression of thickness expansion during electrode assembly cycling and make it difficult to pass drop tests. It will also lead to insufficient substrate and unreliable welding. If the thickness is greater than 0.2mm, the wall thickness of the lower housing 1 will be too large, affecting the overall volume of the cavity and failing to effectively improve the energy density of the electrochemical device. Taking an electrochemical device with dimensions of 5mm thickness, 75mm length, and 75mm width as an example, if the wall thickness is reduced from 0.2mm to 0.05mm, the energy density of the electrochemical device will increase by 7.38%. Therefore, using a lower housing 1 wall thickness of 0.05mm to 0.2mm can ensure that the stamping structural strength requirements and lightweight design of the electrochemical device are met, while also improving the energy density of the electrochemical device. The lower housing 1 can be made of conductive metal materials such as aluminum, steel, stainless steel, nickel, copper, or magnesium alloy.

[0063] like Figure 22 As shown, the lower housing 1 has a protrusion, and the upper cover plate 3 has a groove that mates with the protrusion. The main purpose of the groove and protrusion is to position the components and prevent welding debris from splashing into the first and second housings, thus affecting battery reliability. During assembly, the positioning of the groove and protrusion precisely constrains the translational and rotational degrees of freedom of the upper cover plate and the lower housing, eliminating the need for repeated adjustments during assembly. The components can be directly aligned with the positioning surfaces without the need for additional fixtures.

[0064] In one or more embodiments, the lower housing 1 is provided with a first positioning surface 13 and a second positioning surface 14, which cooperate to form a protrusion, and the upper cover plate 3 is provided with a first limiting surface 31 for welding with the first positioning surface 13 and a second limiting surface 32 for welding with the second positioning surface 14.

[0065] The electrode assembly 2 includes an electrode body 21, which includes a diaphragm and a first electrode and a second electrode with opposite polarities. The diaphragm is disposed between the first electrode and the second electrode to separate them. A first tab 22 and a second tab 23 extend from the electrode body 21. The first electrode is connected to the first tab 22, which is a metal foil that leads out the polarity of the first electrode. The second electrode is connected to the second tab 23, which is a metal foil that leads out the polarity of the second electrode. The first tab 22 and the second tab 23 have opposite polarities.

[0066] Preferably, the electrode assembly 2 can be formed by stacking multiple first electrode sheets and multiple second electrode sheets, or by layering and winding the first electrode sheets and second electrode sheets.

[0067] The lower housing 1 includes a first housing 11 and a second housing 12 that are interconnected, and a stepped structure is formed at the connection between the two. The first housing 11 is used to place the electrode body 21, and the second housing 12 is used to place the electrolyte, the tab, the electrode post assembly, the housing insulation component, and the electrode post insulation component.

[0068] In one or more embodiments, the lower housing 1 is a single-piece structure. In one or more embodiments, the first housing 11 is a rectangular housing, formed by a first surface 111 and a second surface 112, a third surface 113, a fifth surface 115, and a fourth surface 114 connected vertically above it in sequence. The second housing 12 is formed by a seventh surface 122 and an eighth surface 123, a sixth surface 121, and a ninth surface 124 connected vertically above it in sequence. The third surface 113 and the eighth surface 123 are coplanar, the fourth surface 114 and the ninth surface 124 are located on the same plane, and the fifth surface 115 and the seventh surface 122 are vertically connected to form a stepped structure. The seventh surface 122 is provided with a through hole 125 and a liquid injection hole 126 for assembling the terminal assembly 7. This lower housing design allows the battery cell to be inserted from the side with the largest area when it is installed in the housing, solving the problems of difficulty in installing conventional batteries and easy scratching of the battery cell during installation.

[0069] Preferably, the fifth surface 115 and the connecting parts around it are all chamfered.

[0070] The electrochemical device also includes an external circuit board 6, such as Figure 22 and 23 As shown, circuit board 6 has an L-shaped structure with a height of B3. In terms of height, the circuit board is positioned above the second end face, but the sum of the height of the first end face and the height of the circuit board does not exceed the height of the first housing. In terms of length, the length of the circuit board is less than or equal to the length of the second end face, preferably equal to it. This arrangement results in an approximately square structure after the connecting plate and the electrochemical device are assembled, which not only maximizes the space utilization of the electrochemical device but also facilitates its installation on electronic devices. The circuit board is electrically connected to the first and second tabs. The circuit board contains logic circuitry, which, after being connected to the positive and negative terminals of the electrochemical device, allows for logic control of the device.

[0071] like Figure 4As shown, the length of the first housing 11 is A1, and the length of the second housing 12 is A2, satisfying 0.01≤A2 / A1≤0.4. When A1 / A2≥0.01, the seventh surface 122 has sufficient space for setting the electrode assembly, which helps reduce the difficulty of battery fabrication and improves fabrication efficiency. When A1 / A2≤0.4, the space occupied by the electrode assembly 2 is smaller, and the lower housing 1 has more space to accommodate the electrode body 21, which helps improve the battery energy density. In addition, this size design can leave enough space to arrange the circuit board 6. The wall thickness of the second housing 12 is consistent with the wall thickness of the first housing 11. The height of the first housing 11 is B1, and the length of the second housing 12 is B2, satisfying 0.01≤B2 / B1≤0.7. Therefore, one end of the housing is stepped; the thickness of the stepped wall, that is, the thickness of the fifth, sixth, seventh, and eighth surfaces, is ≤0.2mm, which can increase the space of the second housing 12 and improve the cavity energy density. When 0.01≤B2 / B1, the tabs will not affect the welding of the lower shell and the upper cover due to excessive thickness, thus reducing the welding yield. There is also enough space for setting the terminal assembly, which helps to reduce the difficulty of battery manufacturing and improve manufacturing efficiency. When B2 / B1≤0.7, the second shell 12 can accommodate more electrolyte, which helps to improve the battery cycle performance. At the same time, it does not affect the layout of the circuit board.

[0072] The height B2 of the second housing 12 is greater than or equal to the thickness of the first electrode tab (assuming the thickness of the first electrode tab is greater than that of the second electrode tab) + the height of the lower part of the pole post 72 + the thickness of the first insulating pad 51 + the thickness of the first insulating part 41. The sum of the height B2 of the second housing 12 and the height B3 of the external circuit board is less than or equal to the height B1 of the first housing 11, that is, B2 + B3 ≤ B1;

[0073] In the length direction, the length of the second housing 12 is equal to the length of the external circuit board 6, both being A2. In the width direction, the width of the first housing 11 equals the width of the second housing 12 equals the width of the circuit board 6. This arrangement allows the electrochemical device of this invention to be assembled into a cuboid after the external circuit board, facilitating the design of the battery compartment and its assembly with the battery compartment. With this arrangement, the second housing 12 and the circuit board 6 do not occupy additional space in the first housing 11, thereby increasing the energy density of the electrochemical device. Furthermore, besides accommodating the first and second tabs, the remaining space in the second housing 12 can accommodate the free electrolyte, preventing the electrodes from failing due to electrolyte consumption during cycling and further improving the battery's cycle performance. The assembly of the circuit board 6 and the electrochemical device forms an approximately square structure, which not only maximizes the space utilization of the electrochemical device but also facilitates its installation on electronic devices. The circuit board 6 is electrically connected to the first tab 22 and the second tab 23. The circuit board contains logic circuitry, which, after being connected to the positive and negative electrodes of the electrochemical device, allows for logic control of the electrochemical device.

[0074] The first and second electrodes extend from the same end of the electrode assembly and are placed in the second housing. The first and second electrodes are spaced apart to prevent them from contacting each other and short-circuiting. This ensures that the electrodes can be smoothly installed into the second housing without affecting the welding of the lower housing and the upper cover.

[0075] To prevent the battery tabs from falling onto the casing and causing a short circuit during drops or shaking, the casing insulation 4 is disposed on the side of the upper cover plate 1 near the second casing. In one or more embodiments, the casing insulation 4 is an L-shaped integral structure, including a first insulating part 41 and a second insulating part 42 that are perpendicular to each other. The first insulating part 41 is arranged parallel to the tabs and is attached or coated on the upper cover plate 3 to achieve insulation between the second tabs and the lower casing, preventing contact short circuits. The second insulating part 42 is arranged perpendicular to the tabs and is attached or coated on the sixth surface to prevent the second tabs from shifting along the length of the battery and contacting the lower casing 1 to cause a short circuit.

[0076] If the electrode assembly's tabs are positioned too close to the side, a housing insulation component is also required on the eighth side as a precaution. Considering compatibility issues between different battery models, the L-shaped housing insulation component in this design is simultaneously located on the eighth side and the side of the top cover closest to the second housing. The housing insulation component can be insulating tape or coated with an insulating coating.

[0077] In one or more embodiments, the tabs are covered with insulating tape and then adhered to the inner wall of the fifth surface. For example... Figure 10 As shown, the insulating tape completely covers the second tab 23 along the width direction and is then pasted onto the inner wall of the fifth side. It is important to note that the insulating tape should not block the injection hole, otherwise it will affect the subsequent injection process.

[0078] In one or more embodiments, the first tab 22 is covered with insulating tape and then adhered to the inner wall of the fifth surface. For example... Figure 11 As shown, the insulating tape completely covers the first tab 22 and the second tab along the width direction of 23 and is then pasted onto the inner wall of the fifth surface, without obstructing the electrolyte filling hole. This configuration provides the battery with safer performance. Furthermore, the insulating tape covering the tabs prevents the risk of short circuits caused by poor tab welding during drop and tumbling tests.

[0079] In one or more embodiments, the first electrode tab 22 is arranged on the upper cover plate 3, such as Figure 12As shown, insulating tape completely covers the second tab 23 along its width and is then adhered to the inner wall of the fifth surface, without obstructing the electrolyte injection hole. With this arrangement, the first tab 22 and the second tab 23 are positioned on opposite surfaces, with a greater distance between them. This reduces the potential difference generated when both tabs simultaneously contact the electrolyte, minimizing the possibility of electrochemical changes in the casing. This design provides greater safety and extends battery life.

[0080] The pole assembly 7 includes an upper pole 71 and a lower pole 72 fixedly connected below it. The lower pole 72 has a rectangular structure, and the upper pole 71 has a cylindrical structure.

[0081] In one or more embodiments, the upper pole portion 71 and the lower pole portion 72 are welded together as a single unit.

[0082] The lower part 72 of the electrode post is disposed inside the second housing and is welded or abutted to the second electrode tab 23. The upper part 71 of the electrode post is used to connect to the external circuit board 6 through the through hole on the seventh surface to conduct electricity to the electrochemical device. Since the lower housing is made of metal, the first electrode tab 22 can be directly connected to the lower housing, leading out the other polarity through the lower housing. The lower housing can be used as a positive electrode or a negative electrode. If the lower housing is a positive electrode, the electrode post assembly 7 leads out the negative electrode, and vice versa. Since the polarities of the lower housing and the electrode post assembly 7 are different, the electrode post assembly 7 needs to be separated from the lower housing. The electrode post assembly 7 and the lower housing are completely separated by the electrode post insulator 5 to achieve cavity sealing, and the electrode post assembly 7 is insulated.

[0083] The pole insulating component 5 is L-shaped and includes a first insulating pad 51 and a second insulating pad 53 that are perpendicular to each other. The first insulating pad 51 is provided with an insulating protrusion 52, which is a hollow cylindrical structure.

[0084] The first insulating pad 51 is disposed between the lower part 72 of the electrode post and the seventh surface. To prevent short circuit due to contact between the two, the length of the first insulating pad 51 is greater than or equal to the length of the lower part 72 of the electrode post and the width of the first insulating pad 51 is greater than or equal to the width of the lower part 72 of the electrode post, that is, the surface area of ​​the first insulating pad 51 is greater than or equal to the surface area of ​​the lower part 72 of the electrode post. The second insulating pad 52 is disposed inside the sixth surface. To prevent short circuit due to contact between the electrode tab and the sixth surface of the housing after the electrode assembly shakes in the length direction, and at the same time not affecting the assembly of the lower housing and the upper cover, the length of the second insulating pad 53 is greater than or equal to the thickness of the second electrode tab (the one with the larger thickness of the two electrode tabs; for ease of description, we take the example that the thickness of the second electrode tab is greater than the thickness of the first electrode tab) and the length of the second insulating pad 53 is less than or equal to the length of the second housing. The first insulating pad and the second insulating pad are connected with rounded corners, and the rounded corners are consistent with the rounded corners of the housing to ensure a smooth transition. The electrode post insulating component 5 has a certain degree of adhesion and can be directly bonded to the wall of the lower housing, eliminating the need for connecting pieces and other connecting components, reducing costs, and ensuring connection stability.

[0085] In one or more embodiments, Figure 13 The diagram illustrates the state of the first tab 22. The first tab 22 is welded or abutted to any side of the first housing or the side of the top cover closest to the first housing, aiming to achieve electrical connection between the first tab and the lower housing 1, thus energizing the lower housing 1. In conventional batteries, bare cells typically require welding tabs to slightly harder tabs, bending them, and then welding them to the housing to bring out the positive and negative electrodes. This tab welding and bending process occupies significant space within the hard-shell battery casing, resulting in low energy density. In this invention, the bare cell eliminates the need for welding and bending with other tabs. It can be directly led out from the electrode body and welded or abutted to the terminal assembly or housing. Furthermore, the second housing provides sufficient height for installing a circuit board. Therefore, the tabs do not occupy internal space within the housing, significantly improving battery capacity through structural design.

[0086] like Figure 9As shown, the second casing has ample space. Besides accommodating the tabs, terminals, and insulating components, the remaining space can hold more electrolyte, increasing the battery's electrolyte retention and preventing electrode failure due to electrolyte consumption during cycling, thus further improving the battery's cycle performance. Furthermore, lithium plating is more likely to occur near the tabs in conventional batteries than in other areas because the tabs are thicker than other areas. To ensure consistent overall battery thickness, the battery is pressurized, and the thicker tabs naturally bear more pressure. This results in poorer electrolyte wettability in this area, and it also presents areas of active material thinning, making it a high-risk region for lithium plating. In this invention, more free electrolyte is stored in the second casing, providing sufficient electrolyte to the tabs to alleviate lithium plating caused by insufficient electrolyte. Additionally, this flexible casing allows for more diverse and varied tab arrangement and assembly methods.

[0087] Example 1

[0088] Figure 14 The connection between the electrode assembly and the housing can be clearly shown. The electrode body is rectangular and can be completely housed within the first housing. By setting the gap between the electrode body and the lower housing, the designed battery capacity can be obtained. The more electrode bodies 21 housed here, the higher the battery capacity. Therefore, if the electrode body is abutted against the four sides of the first housing, the theoretically maximum battery capacity can be obtained from the structural design.

[0089] The second tab 23 extends from the electrode body. If the electrode body is a wound structure, the second tab is directly welded or abutted to the lower part 72 of the electrode post, and the first tab is directly welded or abutted to the lower housing. If the electrode body is a laminated structure, the second tab is pre-welded ultrasonically before being welded or abutted to the lower part 72 of the electrode post, and the first tab is pre-welded ultrasonically before being welded or abutted to the lower housing. The second tab is parallel to the lower part 72 of the electrode post. This arrangement maximizes the contact area between the lower part 72 of the electrode post and the second tab 23, improving the current flow area and connection stability. In the projection along the height direction, the electrode post insulating component 5 needs to completely cover the lower part 72 of the electrode post and the first tab. In the projection along the length direction, the electrode post insulating component is L-shaped to ensure that the first tab will not have the risk of short circuit with the lower housing in the length direction.

[0090] The pole post assembly 7 is located on the seventh surface for two main reasons. First, if it were located on other wall surfaces, the pole post assembly would be prone to seal failure with the housing under conditions of mechanical abuse such as rollers and drops.

[0091] Furthermore, the other surfaces have relatively large areas, making them prone to deformation under impact. Secondly, the terminal assembly 7 has a small area and is not easily deformed, which also makes it prone to sealing failure. By setting the terminal assembly on the seventh surface 122 on the step along the length of the lower casing, when the battery is subjected to external force, the other walls are impacted first, thus reducing the possibility of deformation of the seventh surface and the terminal assembly. In addition, a reinforcing structure is formed at the step, which enhances the overall structural rigidity of the battery and effectively maintains the sealing between the terminal assembly 7 and the seventh surface 122, reducing the risk of electrolyte leakage and improving battery safety performance.

[0092] In this patent, the distance between the second and fifth surfaces is the length direction of the battery, the distance between the third and fourth surfaces is the width direction of the battery, and the distance between the first surface and the top cover is the thickness of the battery. Since the length of the battery is greater than its width, the length of the battery is greater than its thickness, and the width of the battery is greater than its thickness, by arranging the electrode assembly on the width side, the space occupied by the electrode assembly can be reduced, further improving the battery energy density.

[0093] The gap between the electrode body 21 and the second surface is 0.1-2.5mm. When the gap is greater than 0.1mm, it can reduce the possibility of interference when the electrode assembly is inserted into the shell, which is convenient for cell manufacturing. When the gap is less than 2.5mm, it can further increase the space of the shell, which is beneficial to improving the energy density of the battery. In addition, conventional battery terminal assembly is usually arranged on the fifth surface 115, which means that the first shell not only needs to accommodate the electrode body, but also the tab adapter, tab bending and terminal assembly, which wastes a lot of space. In this patent, since the terminal assembly is arranged on the seventh surface, the first shell only needs to accommodate the electrode body of the electrode assembly. In the same shell space, this patent can make the electrode body longer so that more electrode material can be placed in the first shell, thereby improving the energy density of the battery.

[0094] Compared to traditional batteries where the tabs are welded together and then bent, this patented design allows the first tab 22 and the second tab 23 to extend directly from the same side of the electrode body 21 to the welding point with the lower casing 1, eliminating the need for additional tabs. This saves more usable space and can improve energy density in the limited casing space. Furthermore, the connection point between the first and second tabs (hereinafter referred to as "tabs") and the electrode body is a weak point. This design places it at the stepped corner of the lower casing, a location with high structural strength, reducing the possibility of tab failure after external impact. The tabs extend directly without bending, which is safer than the traditional 180° bend and significantly reduces the risk of fatigue fracture. Additionally, since current flows through the tabs during charging and discharging, heat is concentrated there. This design places the entire path of the tab close to or in contact with the casing, effectively placing the heat-generating components of the battery on a heat dissipation device, allowing heat to be dissipated promptly and reducing battery thermal failure. The design offers several advantages. First, the welding point between the electrode assembly 7 and the lower housing 1 is located in the second housing, away from the electrode body 21. This design prevents the heat generated during welding of the tab to the seventh surface from affecting the first housing, and welding residue also avoids this issue. Second, this design improves production efficiency and reduces costs. Since the tab extends directly into the second housing and is welded to the seventh surface, no additional bending fixture is needed. Welding and housing insertion can be completed simply by controlling the welding length between the tab and the seventh surface. This design makes it easier to maintain the tab's shape compared to conventional battery designs. Third, conventional batteries typically consist of a large annular frame and two smaller top and bottom covers welded together. The electrode assembly is first welded to one of the top or bottom plates before being inserted into the annular frame. This design makes electrode assembly insertion difficult, easily causing the separator to wrinkle and the electrode sheets to be scratched and damaged, increasing the risk of short circuits and capacity loss, and requiring a longer insertion time. In contrast, this patent design inserts the electrode assembly into the lower housing from the largest surface, solving these problems.

[0095] Example 2

[0096] like Figure 15As shown, the tabs of the electrode assembly are bent after the junction of the first and fifth surfaces, extending towards the top cover and along the step to the second housing, where they are welded. Compared to traditional batteries where the tabs are bent after being welded, this design allows the first and second tabs to run along both surfaces to the welding point with the housing, eliminating the need for additional tabs and saving more usable space. In the limited space of the housing, this can improve energy density. Furthermore, both bends of the tabs occur at the corners of the housing, a location with high structural strength, reducing the possibility of tab failure after external impact. The 90° bend angle is also safer than the traditional 180° bend, reducing the risk of tab fatigue fracture. The welding point between the electrode assembly and the housing is located at... The second casing, located away from the electrode body, does not affect the first casing due to the heat generated during the welding connection between the tab and the seventh surface. Even if abnormalities occur at the welding point (such as poor welding or overheating leading to metal spatter), the direct impact on the safety of the main cell is greatly reduced. In addition, this design can improve production efficiency and reduce production costs because the tab is first gathered to one side and then bent along the step. The step acts as a bending positioning guide, so there is no need to add an additional bending fixture. As long as the length of the welding between the tab and the seventh surface is controlled, the bending into the casing can be completed. This design makes it easier to maintain the bending shape than conventional battery designs.

[0097] Example 3

[0098] like Figure 16Since the first and second tabs of the battery have opposite polarities, and people's demand for energy density is increasing, the difference between this embodiment and embodiment 2 is that a head protective adhesive 9 is added to the side of the second tab near the seventh surface. In the projection of the head protective adhesive 9 in the width direction, the projection can completely cover the second tab, so as to play the role of insulation and safety protection. The reasons for adding head protective adhesive are as follows: 1. The distance between the side of the electrode body closest to the seventh surface and the side of the seventh surface closest to the electrode is designed to be increasingly smaller. Therefore, under conditions of drop, roller, transportation, or other mechanical abuse, the second electrode tab may deform and shift, coming into contact with the seventh surface, resulting in a short circuit; 2. The distance between the side of the electrode body closest to the seventh surface and the side of the seventh surface closest to the electrode is designed to be increasingly smaller. Therefore, under conditions of drop, roller, transportation, or other mechanical abuse, the seventh surface may deform and shift, coming into contact with the seventh surface, resulting in a short circuit; 3. The distance between the side of the electrode body closest to the fifth surface and the side of the fifth surface closest to the electrode is designed to be increasingly smaller. Therefore, under conditions of drop, roller, transportation, or other mechanical abuse, the fifth surface may deform and come into contact with the second electrode tab, resulting in a short circuit. The head is protected by a protective adhesive to prevent short circuits between the second electrode tab and the lower housing. At the same time, this design allows for a smaller distance between the side of the electrode body closest to the seventh surface and the side of the seventh surface closest to the electrode, while ensuring safety, thereby achieving higher energy density.

[0099] Example 4

[0100] like Figure 17 The difference between this embodiment and embodiment 3 is that the head protective adhesive 9 is set on the lower housing 3. This design achieves the same effect as embodiment 3, but it is more convenient from the perspective of operator operation and manufacturing. This is because the positional accuracy of applying the head protective adhesive is relatively low, and it is easier to operate when the housing is used as a guide.

[0101] Example 5

[0102] like Figures 18 to 20In this embodiment, the position of the head protective adhesive is the same as in Embodiment 3 or Embodiment 4. The tab portion of the electrode assembly is bent after the junction of the first and fifth surfaces and then welded to the metal strip 8. The metal strip 8 is used for welding and connecting to the electrode post assembly 7. There are various bending and connection methods for the metal strip, and this patent does not limit them. In the projection along the length direction, the width of the metal strip 8 is 70%-99% of the tab width. Within this range, sufficient current density and welding strength can be obtained. At the same time, excessive width will not cause assembly interference problems or add extra battery weight. Excessive width will also lead to the risk of short circuit between the two tabs arranged side by side. The material of the metal strip is the same as that of the second tab. Choosing the same material can reduce resistance, further reduce heat generation, and improve safety and battery life.

[0103] In this application, the height of the fifth surface plus the thickness of the electrode assembly > the length of the protective adhesive head > the height of the fifth surface. If the length of the protective adhesive head is too small, the gap between the electrode body and the fifth surface will be too small, and the second electrode tab may come into contact with the lower casing during drop tests or shaking, leading to a short circuit. If the length of the protective adhesive head is too long, it will extend to the through hole 125, causing blockage and further affecting the installation of the electrode assembly. In the length direction, the projection of the protective adhesive head must completely cover the second electrode tab to prevent short circuits during use.

[0104] The lower housing 1 and the upper cover 3 are laser-welded together, and an electrolyte is injected to form a battery.

[0105] This invention also protects an electronic device that utilizes the aforementioned electrochemical device.

[0106] The structure of the lower housing and electrode assembly designed in this application effectively avoids fatigue fracture during tab bending, eliminates the need for tab welding and bending processes, improves battery reliability, increases production efficiency, and reduces production costs. The stepped structure reduces heat at the bending point, and the non-direct structure inside the first and second housings increases the battery's liquid retention capacity, significantly improving cycle performance and energy density. Furthermore, conventional cell insertion involves inserting the cell into the housing from the smaller side, leading to difficulty and increased susceptibility to damage. This patent solves this problem, enabling convenient and damage-free cell insertion.

[0107] It should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An electrochemical device, characterized in that: include An electrode assembly includes an electrode body and a first electrode tab and a second electrode tab extending from the same side thereon; The electrode assembly is used to draw out the polarity of the electrode body; The lower housing includes a first housing and a second housing that are interconnected and form a step at their connection. The first housing is used to place the electrode body, and the second housing is used to place the tabs, electrolyte and electrode post assembly, housing insulation and electrode post insulation. The connection between the tabs and the electrode body is located at the step. The upper cover plate is used to form a sealed structure when connected to the lower housing; The housing insulation and the pole insulation are located between the upper cover and the lower housing, and are used to insulate the pole lugs from the lower housing.

2. The electrochemical device according to claim 1, characterized in that: The wall thickness of the lower shell is 0.05mm to 0.2mm.

3. An electrochemical device according to claim 2, characterized in that: The first housing is a rectangular housing, formed by the first surface and the second, third, fifth and fourth surfaces connected vertically above it in sequence. The second housing is formed by the seventh surface and the eighth, sixth and ninth surfaces connected vertically above it in sequence. The third and eighth surfaces are coplanar, the fourth and ninth surfaces are on the same plane, and the fifth and seventh surfaces are connected vertically to form a step. The seventh surface is provided with a through hole for assembling the pole assembly and an injection hole for injecting liquid.

4. An electrochemical device according to claim 3, characterized in that: The length of the first shell is A1, and the length of the second shell is A2, satisfying 0.01≤A2 / A1≤0.4; the height of the first shell is B1, and the length of the second shell is B2, satisfying 0.01≤B2 / B1≤0.

7.

5. An electrochemical device according to claim 3, characterized in that: The housing insulation component is an L-shaped integral structure, including a first insulating part and a second insulating part that are perpendicular to each other. The first insulating part is arranged parallel to the second tab and is pasted or coated on the upper cover plate. The second insulating part is arranged perpendicular to the second tab and is pasted or coated on the sixth surface. The housing insulation component is made of rigid insulating colloid, insulating paper, or insulating coating.

6. An electrochemical device according to claim 3, characterized in that: The electrode assembly includes an upper electrode part and a lower electrode part fixedly connected below it. The lower electrode part has a rectangular structure, and the upper electrode part has a cylindrical structure. The lower electrode part is disposed inside the second housing and fixedly connected to the second electrode tab. The upper electrode part passes through a through hole on the seventh surface and is connected to an external circuit board to conduct electricity to the electrochemical device.

7. An electrochemical device according to claim 3, characterized in that: The pole insulation component is L-shaped and includes a first insulating pad and a second insulating pad that are perpendicular to each other. The first insulating pad has an insulating protrusion for passing through the upper part of the pole.

8. An electrochemical device according to claim 6, characterized in that: The second tab extends from the electrode body. If the electrode body is a wound structure, the second tab is directly welded or abutted to the lower part of the electrode post, and the first tab is directly welded or abutted to the lower shell. If the electrode body is a laminated structure, the second tab is pre-welded with ultrasonic waves before being welded or abutted to the lower part of the electrode post, and the first tab is pre-welded with ultrasonic waves before being welded or abutted to the lower shell. The second tab is parallel to the lower part of the electrode post.

9. An electrochemical device according to claim 1, characterized in that: The welding point between the pole assembly and the lower housing is located inside the second housing.

10. An electronic device, characterized in that, The electronic device includes the electrochemical device according to any one of claims 1 to 9.

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