Lithium ion battery and electronic product

Abstract

The utility model relates to the field of lithium ion batteries, and discloses a lithium ion battery and an electronic product, and the battery comprises a steel shell, a battery core body, an inner positive electrode end plate and an insulating part. A penetrating positive pole through hole is formed in the shell wall of the steel shell, a through hole with the aperture smaller than that of the positive pole through hole is formed in the insulating part, the through hole of the insulating part is located in the positive pole through hole, the inner positive pole end plate is arranged on the inner wall of the steel shell through the insulating part, and the insulating part insulates and separates the steel shell and the inner positive pole end plate and seals the positive pole through hole. The positive electrode of the battery cell body is welded at the first end part of the inner positive electrode end plate, and the top surface of the second end part of the inner positive electrode end plate is exposed out of the steel shell from the through hole of the insulating part to serve as the positive electrode of the lithium ion battery or is connected with the positive electrode arranged outside the steel shell through the through hole of the insulating part; a current limiting position with the cross section smaller than that of the first end part and that of the second end part is arranged between the first end part and the second end part of the positive pole through hole, current flowing out of the positive pole of the battery core body sequentially passes through the first end part, the current limiting position and the second end part of the inner positive pole end plate, and when the current is greater than a preset threshold value, the current limiting position is fused. The battery is easy to disassemble and replace, and has strong current-limiting protection.

Description

Technical Field

[0001] The utility model relates to the field of battery manufacturing, in particular to a lithium ion battery and an electronic product. Background Art

[0002] As the application of smart wearable products becomes more and more widespread, people's demand for secondary rechargeable batteries is also increasing.

[0003] Soft-pack batteries sealed with aluminum-plastic film are widely used due to their mature preparation process. However, the inventors found in the process of conducting the present invention that soft-pack lithium-ion batteries have the following defects:

[0004] The space at the folded edge in the width direction of the soft-pack battery and the sealing part of the tab cannot be effectively utilized, resulting in low volume energy density of the battery.

[0005] The heat dissipation is poor, especially with the development and promotion of fast charging technology, its heat dissipation effect cannot meet the increasingly higher heat dissipation requirements.

[0006] The positive and negative electrodes of soft-pack lithium-ion batteries are soft ears heat-sealed between aluminum-plastic films, which are poorly replaceable and cannot meet the requirements of the new version of the battery regulation (EU) 2023 / 1542 that the battery must be removable and replaceable. Summary of the invention

[0007] One of the purposes of the embodiments of the present utility model is to provide a lithium-ion battery and an electronic product that are easy to disassemble and replace and have strong current limiting protection.

[0008] In a first aspect, a lithium-ion battery provided in this embodiment includes a steel shell, a battery cell, an inner positive terminal plate, and an insulating member.

[0009] A positive electrode through hole is provided on any shell wall of the steel shell, a through hole with a smaller diameter than the positive electrode through hole is provided on the insulating member, and the through hole of the insulating member is located inside the positive electrode through hole.

[0010] The inner positive terminal plate is arranged on the inner wall of the steel shell through the insulating member, and the insulating member insulates and separates the steel shell and the inner positive terminal plate, and seals the positive through hole.

[0011] The positive electrode of the battery cell is welded to the first end of the inner positive terminal plate.

[0012] The top surface of the second end of the inner positive terminal plate is exposed from the through hole of the insulating member to the steel shell as the positive electrode of the lithium ion battery, or is connected to the positive electrode arranged outside the steel shell through the through hole of the insulating member.

[0013] Between the first end and the second end of the inner positive terminal plate is a current limiting position with a cross-section smaller than that of the first end and the second end. The current flowing out from the positive electrode of the battery cell passes through the first end, the current limiting position, and the second end of the inner positive terminal plate in sequence. When the current is greater than or equal to a predetermined threshold, the current limiting position is blown.

[0014] Optionally, it also includes rivets, an outer positive terminal plate,

[0015] The insulating member comprises an inner insulating set and an outer insulating film.

[0016] The inner insulating set comprises: an integrated insulating collar and an insulating skirt, wherein the insulating skirt is formed by radially extending outward along the outer edge of the bottom end of the insulating collar by a predetermined width, the insulating skirt is closely attached to the inner wall of the steel shell, the insulating collar is sleeved in the positive through hole, and the end thereof extends out of the shell wall.

[0017] The outer insulating film and the outer positive terminal plate are respectively provided with a through hole, and are collectively sleeved on the outer side of the insulating sleeve ring extending outside the steel shell. The outer insulating film is closely attached to the outer wall of the steel shell, and the outer positive terminal plate is closely attached to the top surface of the outer insulating film. The outer insulating film insulates and separates the outer positive terminal plate from the shell wall.

[0018] The core of the rivet passes through the through hole of the second end of the inner positive terminal plate, the insulating sleeve, the outer insulating film, and the outer positive terminal plate in sequence from the inside to the outside. One head of the rivet is tightly against the bottom surface of the first end of the inner positive terminal plate, and the other head is tightly against the top surface of the outer positive terminal plate.

[0019] The inner insulating set and the outer insulating film insulate and separate the shell wall from the rivet, the inner positive terminal plate and the outer positive terminal plate.

[0020] Optionally, the top surface of the outer positive terminal plate is further provided with: a first annular step surrounding the through hole of the outer positive terminal plate, lower than the top surface of the outer positive terminal plate, and in a continuous and closed shape,

[0021] The outer edge of the head of the rivet is tightly against the top surface of the first annular step.

[0022] Optionally, the insulating member is an insulating rubber layer, the insulating rubber layer has a through hole with a pore size equal to or smaller than the positive electrode through hole, the insulating rubber layer is closely attached to the inner surface of the shell wall, and the through hole of the insulating rubber layer is located in the positive electrode through hole.

[0023] A boss having a diameter smaller than that of the positive through hole is provided on the top surface of the second end of the inner positive terminal plate, and the boss passes through the through hole of the insulating rubber layer and is exposed outside the shell wall, serving as the positive electrode of the lithium-ion battery. The top surface of the inner positive terminal plate surrounding the boss is attached to the bottom surface of the insulating rubber layer.

[0024] The positive electrode of the battery cell is welded to the bottom surface of the first end portion of the positive terminal plate.

[0025] Optionally, an adhesive layer is provided between the top surface of the inner positive terminal plate surrounding the boss and the bottom surface of the insulating adhesive layer.

[0026] Optionally, the steel shell comprises:

[0027] The bottom shell comprises a shell opening, a side wall surrounding the shell opening and a shell bottom facing the shell opening, wherein a second annular step is provided on the inner wall near the shell opening, and the second annular step surrounds the inner wall to form a continuous closed ring.

[0028] The outer edge of the bottom surface of the steel cover plate is in contact with the top surface of the second annular step, and the metals of the two surfaces are melted and sealed, and the cover plate seals the shell opening.

[0029] Optionally, the steel shell comprises:

[0030] The bottom shell comprises a shell opening, side walls surrounding the shell opening and a shell bottom facing the shell opening, wherein each of the side walls is folded outward at the shell opening to form a skirt that continuously surrounds the shell opening.

[0031] The outer edge of the bottom surface of the steel cover plate is in contact with the top surface of the skirt of the bottom shell, and the metals of the two surfaces are melted and sealed to seal the shell opening.

[0032] Optionally, at least one explosion-proof portion is provided on at least any shell wall of the steel shell.

[0033] The wall thickness at the location of the explosion-proof portion is thinner than the wall thickness of the steel shell and / or the cover plate.

[0034] Optionally, an injection hole is further provided on any shell wall of the steel shell, and a sealing metal sheet is provided on the injection hole. The bottom surface of the sealing metal sheet is in contact with the outer surface of the shell wall outside the injection hole, and the metals of the adjacent surfaces are molten and sealed, and the sealing metal sheet seals the injection hole.

[0035] In a second aspect, an electronic product provided by an embodiment of the utility model includes a power supply compartment,

[0036] The power supply compartment is provided with any of the above-mentioned lithium-ion batteries.

[0037] The positive electrode and the negative electrode of the lithium ion battery are electrically connected to the positive electrode and the negative electrode of the driving circuit of the electronic product respectively.

[0038] It can be seen from the above that the application of the technical solution of this embodiment is beneficial to improving the capacity of the lithium-ion battery.

[0039] On the other hand, the steel shell assembly structure of this embodiment is beneficial to improving the heat dissipation of the battery; it is particularly suitable for fast charging and large current discharge; and the lithium-ion battery of this solution is easier to disassemble and replace; it is conducive to the maintenance and disassembly and recycling of lithium-ion batteries, and is more environmentally friendly.

[0040] In addition, this embodiment sets a current limiting position on the inner positive terminal plate inside the lithium-ion battery, so that when the current is greater than a predetermined threshold, the current limiting position generates heat and melts, thereby disconnecting the current loop from the inside of the lithium-ion battery, thereby achieving strong current limiting protection for the lithium-ion battery and improving the power safety of the lithium-ion battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of this application, and do not constitute an improper limitation of the present invention.

[0042] Figure 1 A schematic diagram of the three-dimensional structure of a lithium-ion battery provided in Example 1 of the utility model;

[0043] Figure 2 A schematic diagram of the three-dimensional structure of the lithium-ion battery provided in the first embodiment of the present utility model from another viewing angle;

[0044] Figure 3 A schematic diagram of the side structure of a lithium-ion battery provided in Embodiment 1 of the present utility model;

[0045] Figure 4 A schematic diagram of the three-dimensional structure of a steel shell of a lithium-ion battery provided in Embodiment 1 of the present utility model;

[0046] Figure 5 for Figure 4 The schematic diagram of the exploded three-dimensional structure of the steel shell before riveting the outer positive terminal plate;

[0047] Figure 6 A schematic diagram of the top view of a cover plate of a lithium-ion battery provided in the first embodiment of the present utility model;

[0048] Figure 7 A bottom view of the structure of a cover plate of a lithium-ion battery provided in the first embodiment of the utility model;

[0049] Figure 8 A schematic diagram of a perspective structure of a cover plate of a lithium-ion battery provided in a first embodiment of the utility model from a side view;

[0050] Fig. 9 A schematic diagram of the three-dimensional structure of a lithium-ion battery provided in the second embodiment of the present utility model;

[0051] Fig.10 A schematic diagram of a top view of a lithium-ion battery provided in Embodiment 2 of the present utility model;

[0052] Fig.11 A bottom view structural diagram of a lithium-ion battery provided in Embodiment 2 of the present utility model;

[0053] Fig.12 A schematic diagram of a side view of a lithium-ion battery provided in the second embodiment of the present utility model;

[0054] Fig.13 A schematic diagram of the three-dimensional structure of a steel shell of a lithium-ion battery provided in the second embodiment of the utility model;

[0055] Fig.14 A schematic diagram of the top view of a steel shell of a lithium-ion battery provided in the second embodiment of the utility model;

[0056] Fig.15 A bottom view structural diagram of a steel shell of a lithium-ion battery provided in Embodiment 2 of the present utility model;

[0057] Fig.16 A schematic diagram of the three-dimensional structure of a cover plate of a lithium-ion battery provided in the second embodiment of the present utility model;

[0058] Fig.17 A schematic diagram of a top view of a cover plate of a lithium-ion battery provided in Embodiment 2 of the present utility model;

[0059] Fig.18 A bottom view structural schematic diagram of a cover plate of a lithium-ion battery provided in Embodiment 1 of the utility model;

[0060] Fig.19 for Fig.18 AA cross-sectional structure diagram;

[0061] Fig. 20 for Fig.19 Schematic diagram of the decomposition structure.

[0062] Fig.21 This is a schematic diagram of the exploded structure of another bottom shell of the third embodiment.

[0063] 1: bottom shell; 11: shell bottom; 12: side wall; 13: second annular step;

[0064] 14: first positive electrode through hole; 15: skirt; 2: cover plate; 21: second positive electrode through hole;

[0065] 3: rivet; 31: first head; 32: second head; 33: core; 4: outer positive terminal plate;

[0066] 41: first annular step; 5: inner insulating rubber part; 51: insulating sleeve; 52: insulating skirt;

[0067] 6: external insulating film; 7: injection hole; 71: sealing metal sheet; 8: internal positive terminal plate;

[0068] 81: first end; 82: second end; 83: flow limiting position; 84: boss;

[0069] 85: insulating rubber layer; 9: negative terminal plate; 10: explosion-proof part. DETAILED DESCRIPTION

[0070] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The schematic embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0071] Examples of embodiments of the present invention described in detail below are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions.

[0072] The embodiments described below with reference to the drawings attached to this specification are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention. In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

[0073] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0074] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0075] Embodiment 1.

[0076] See also Figure 1-8 .

[0077] This embodiment provides a steel shell lithium ion battery, which includes a bottom shell 1, a cover plate 2, a battery cell (not shown in the figure, and the specific preparation can refer to the prior art), an inner positive terminal plate 8, an insulating member and an outer positive terminal plate 4.

[0078] The bottom shell 1 is made of stainless steel plate, one end of the bottom shell 1 is a shell opening, the closed end opposite to the shell opening is a shell bottom 11, and the shell wall surrounding the shell bottom 11 and extending from the shell bottom 11 to the shell opening is a side wall 12.

[0079] An annular step with a certain width (referred to as the second annular step 13) is also formed on the inner wall of the side wall 12. The second annular step 13 surrounds the side wall 12 on all sides and is in a continuous closed annular shape. It is parallel to the end face of the side wall 12 at the shell opening. The top face of the second annular step 13 is lower than the shell opening. The area of ​​the closed figure surrounded by the inner edge of the second annular step 13 is smaller than the area of ​​the closed figure surrounded by the inner edge of the shell opening. The bottom shell 1 can be prepared by stamping by a stamping process. A stamping part with the same shape as the shell bottom 11 of the bottom shell 1 is used to stamp a steel plate to form a cavity. The shell opening is formed at the stamping end of the stamping part. Another stamping part with a stamping area larger than the original stamping area is further used for further stamping, so that a section of the side wall 12 near the shell opening is radially bent outward to form a second annular step 13 near the shell opening. The width of the top face of the second annular step 13 is the same at all places. The second annular step 13 has a certain height from the shell opening, which is equal to the thickness of the cover plate 2. The closed figure formed by the outer edge of the second annular step 13 is consistent with the outer shape of the cover plate 2. The second annular step 13 is the bearing platform of the cover plate 2. When the cover plate 2 is sealed to the top surface of the second annular step 13, a circle of the bottom surface of the cover plate 2 close to the outer edge is face to face with the top surface of the second annular step 13, and the end surface of the outer edge of the cover plate 2 is in contact with the inner wall of the side wall 12. The cover plate 2 is sunk and sealed on the inner side of the shell opening, and there is a seamless design between the cover plate 2 and the shell opening.

[0080] The cover plate 2 can be but not limited to a sheet steel plate. A vertical welding machine is used to weld along the edge of the top surface of the cover plate 2. The metals of the two surfaces of the cover plate 2 and the second annular step 13 are melted and fully sealed. The structure of welding the cover plate 2 with the second annular step 13 of this embodiment is conducive to accurately positioning the cover plate 2, avoiding displacement of the cover plate 2 and affecting the welding effect of the cover plate 2, ensuring the sealing of the cover plate 2 and the bottom shell 1, and relative to the end surface of the side wall 12 of the shell opening of the cover plate 2. With this design, the width of the top surface of the second annular step 13 can be designed as the welding area of ​​the cover plate 2. The welding area of ​​the cover plate 2 is not limited to the thickness of the shell wall of the bottom shell 1, which is conducive to the ultra-thin design of the bottom shell 1 and the cover plate 2, so as to make full use of the volume of the lithium-ion battery and improve the volume energy density. With the steel shell of the structure of this embodiment, when repairing the battery cell, the steel shell can be welded and disassembled without damage, and the battery cell can be repaired or replaced, which meets the environmentally friendly application requirements of the detachable and repairable lithium-ion battery.

[0081] As an illustration of this embodiment, it is preferred that the distance between the top surface of the second annular step 13 located on the inner wall of the side wall 12 and the shell opening is designed to be equal to the thickness of the cover plate 2. After the cover plate 2 is welded to the second annular step 13, the top surface of the cover plate 2 is flush with the end surface of the shell opening. This design makes the shape of the lithium-ion battery have good flatness and consistency, which is conducive to fully utilizing the space of the shell and increasing the capacity of the lithium-ion battery.

[0082] A through first positive electrode through hole 14 is provided on any side wall of the steel shell, such as but not limited to the side wall 12 of the bottom shell 1 located at one width end of the battery.

[0083] As an illustration of this embodiment, the inner insulation kit of this embodiment includes an inner insulation kit 5 and an outer insulation film 6 .

[0084] The inner insulating sleeve 5 includes an insulating sleeve 51 and an insulating skirt 52, which are integrally formed by injection molding. The height of the insulating sleeve 51 is greater than the wall thickness of the bottom shell 1. When the insulating sleeve 51 is sleeved in the first positive through hole 14, the end of the insulating sleeve 51 extends out of the bottom shell 1 by a certain height. The inner diameter of the insulating sleeve 51 is equal to or slightly smaller than the outer diameter of the core 33 of the rivet 3, so that when the core 33 of the rivet 3 passes through the insulating sleeve 51, the insulating sleeve 51 is tightly sleeved outside the rivet 3, and the outer diameter of the insulating sleeve 51 is equal to or slightly smaller than the aperture of the first positive through hole 14 on the bottom shell 1, so that the insulating sleeve 51 with the core 33 of the rivet 3 is sealed in the first positive through hole 14, and the first positive through hole 14 is sealed.

[0085] The insulating skirt 52 is located at the bottom end of the insulating collar 51. The insulating skirt 52 is an insulating sheet extending radially outward from the outer edge of the insulating collar 51 to a certain width. The insulating skirt 52 is a sheet-shaped insulating skirt 52 surrounding the insulating collar 51. The outer edge of the insulating skirt 52 is equal to or larger than the outer edge of the second head 32 of the rivet 3 located in the bottom shell 1.

[0086] The thickness of the insulation layer of the insulation collar 51 and the insulation skirt 52 may be the same or different.

[0087] The outer insulating film 6 is in sheet shape, and has a through hole on the outer insulating film 6, the aperture of the through hole is equal to or slightly larger than the outer diameter of the insulating collar 51, and the insulating collar 51 extends through the shell wall 12 and extends through the through hole of the outer insulating film 6. The outer positive terminal plate 4 and the inner insulating sleeve 5 are placed in the bottom shell 1 from the shell opening, and the insulating collar 51 passes through the first positive through hole 14 from the inner surface of the shell wall and is sleeved in the first positive through hole 14, and the end of the insulating collar 51 extends out of the bottom shell 1 by a certain height, slightly exceeding the outer surface of the side wall 12 of the bottom shell 1. The insulating skirt 52 located at the bottom end of the inner insulating sleeve 5 is tightly attached to the inner wall of the side wall 12 surrounding the outer periphery of the first positive through hole 14, and the outer insulating film 6 is tightly attached to the outer surface of the side wall 12. The aperture of the through hole of the outer insulating film 6 is slightly narrower than the aperture of the through hole of the outer positive terminal plate 4. Both are directly opposite to the first positive through hole 14 of the bottom shell 1. The outer positive terminal plate 4 is tightly attached to the top surface of the outer insulating film 6. The outer insulating film 6 and the outer positive terminal plate 4 are tightly sleeved on the outside of the insulating ring 51 extending out of the side wall 12 of the bottom shell 1. The outer insulating film 6 is tightly attached to the outer surface of the side wall 12 of the bottom shell 1, and is spaced between the side wall 12 of the bottom shell 1 and the outer positive terminal plate 4.

[0088] The inner positive terminal plate 8 includes a first end 81 for connecting the positive electrode of the battery body, and a second end 82 for connecting the outer positive terminal plate 4 as the positive electrode of the battery. Between the first end 81 and the second end 82 is a current limiting position 83, which is connected in series between the first end 81 and the second end 82. The cross section at the current limiting position 83 is much smaller than the cross section of the first end 81 and the second end 82, that is, the inner positive terminal plate 8 is greatly narrowed at the current limiting position 83. One head of the rivet 3 is tightly against the bottom surface of the second end 82 of the inner positive terminal plate 8, and the core of the rivet 3 passes through from the inside to the outside in sequence: the second end 82 of the inner positive terminal plate 8, the insulating collar 51 of the inner insulating set 5, the outer insulating sheet 6, and the outer positive terminal plate 4. The head of the rivet 3 extending from the outer positive terminal plate 4 outside the steel shell is tightly against the top surface of the outer positive terminal plate 4. Under the fastening action of the two heads of the rivet 3, the bottom surface of the insulating skirt 52 of the inner insulating set 5 is sealed and tightly against the inner wall of the shell wall. The insulating skirt 52 is insulated and spaced between the second head 32 of the rivet 33 and the side wall 12 of the bottom shell 1, and is spaced between the side wall 12 of the bottom shell 1 and the current limiting position 83 and the first end 81 of the inner positive terminal plate 8; the first head 31 of the rivet 33 extends out of the side wall 14 of the bottom shell 1, and is pressed against the outer positive terminal plate 4 with a certain pressure. Under the penetration and clamping action of the rivet 3, the insulating skirt 52 and the outer insulating film 6 tightly seal the first positive through hole 14.

[0089] The inner insulating set and the outer insulating sheet 6 provide insulating spacing between the steel shell and the interconnected rivets 3, the inner positive terminal plate 8 and the outer positive terminal plate 4, and seal the first positive through hole 14 of the steel shell.

[0090] The negative electrode of the battery cell is connected to any part of the steel shell, and the steel shell is used as the negative electrode of the battery, and the outer positive terminal plate 4 connected to the positive electrode of the battery cell through the inner positive terminal plate 8 and the rivet 3 is used as the positive electrode of the battery. The current flows out from the positive electrode of the battery cell, passes through the first end 81 of the inner positive terminal plate 8, the current limiting position 83, the second end 82, the rivet 3, the outer positive terminal plate 4 in sequence, and then is output to the external electrical equipment and returns to the negative electrode of the battery.

[0091] As can be seen from the above, by adopting the scheme of this embodiment, the cross-section of the current limiting position 83 is set so that when the current is greater than the predetermined threshold value, the current limiting position 83 generates heat and melts, thereby disconnecting the current loop from the inside of the lithium-ion battery, thereby realizing strong current limiting protection for the lithium-ion battery and improving the power safety of the lithium-ion battery.

[0092] As an illustration of this embodiment, in a natural state, the size of the external insulating film 6 can be the same as the size of the external positive terminal plate 4. Under the penetration and clamping action of the rivet 33, the external insulating film 6 is deformed and slightly wider than the external positive terminal plate 4 and exceeds the outer edge of the external positive terminal plate 4, thereby ensuring the insulation isolation between the external positive terminal plate 4 and the bottom shell 1. It is also possible to select an external insulating film 6 that is wider than the external positive terminal plate 4 in a natural state.

[0093] As an illustration of this embodiment, a circle of annular steps lower than the top surface of the outer positive terminal plate 4 can be further provided on the top surface of the outer positive terminal plate 4 close to the through hole, recorded as the first annular step 41, so that the outer edge of the head of the rivet 33 is tightly against the top surface of the first annular step 41, thereby realizing the fastening and riveting of the outer positive terminal plate 4. The use of this design is conducive to improving the riveting positioning of the head of the rivet 33 and improving the assembly consistency of the lithium-ion battery.

[0094] As an illustration of this embodiment, the head of the rivet 33 can be made flush with the top surface of the outer positive terminal plate 4 , or the first head 31 of the rivet 33 can be made slightly higher than the top surface of the outer positive terminal plate 4 .

[0095] In this embodiment, the core 33 of the rivet 33 is solid, so as to reduce the impedance of the positive electrode of the lithium-ion battery. The solid core 33 is helpful to enhance the riveting strength.

[0096] During the lithium-ion battery assembly process, the outer positive terminal plate 4 and the inner positive terminal plate 8 are pre-riveted on the side wall 14 of the bottom shell 1 with insulation intervals according to the above method as a preparation.

[0097] This embodiment uses a laminated lithium-ion battery cell, and the shapes of the pole pieces of the laminated battery cell are respectively consistent with the shape of the shell bottom 11 of the bottom shell 1, and the thickness of the laminated battery cell is the same or substantially the same as the height from the shell bottom 11 of the bottom shell 1 to the second annular step 13, so that the space in the cavity of the bottom shell 1 is fully utilized to improve the volume energy density of the lithium-ion battery.

[0098] Especially when applied to square batteries or batteries with a special bottom shell 1, compared with cylindrical wound battery cells, the laminated lithium-ion battery using the above-mentioned solution can fully utilize the space in the shell and improve the volume energy density of the battery.

[0099] As can be seen from the above, the application of the technical solution of this embodiment has the following beneficial effects:

[0100] On the one hand, it is beneficial to improve the volume energy density of lithium-ion batteries;

[0101] On the other hand, compared with the soft-pack lithium-ion battery, the bottom shell 1 structure of this embodiment has better heat dissipation and is particularly suitable for fast charging and high current discharge;

[0102] Moreover, compared with soft-pack lithium-ion batteries, the lithium-ion batteries of this solution are easy to disassemble and recycle, easy to replace, and their application is more in line with environmental protection requirements.

[0103] In addition, the present embodiment sets a current limiting position 83 on the inner positive terminal plate 8 inside the lithium-ion battery, so that when the current is greater than a predetermined threshold, the current limiting position 83 generates heat and melts, thereby disconnecting the current loop from the inside of the lithium-ion battery, thereby achieving strong current limiting protection for the lithium-ion battery and improving the power safety of the lithium-ion battery.

[0104] As an illustration of this embodiment, a liquid injection hole 7 may be further provided on the bottom shell 1, preferably but not limited to, the liquid injection hole 7 is provided on the side wall 12. When assembling the battery cell, after the positive and negative electrodes of the battery cell and the bottom shell 1 are welded, and the cover plate 2 is welded, the electrolyte is injected, which can avoid the electrolyte contaminating the welding surface and affecting the welding effect, resulting in a cold weld.

[0105] In addition, compared with the solution in which the injection hole 7 is arranged on the cover plate 2 or the shell bottom 11, the injection hole 7 is arranged on the side wall 12, and the electrolyte penetrates from the side of the laminated battery cell, which is more conducive to improving the penetration efficiency of the electrolyte, improving the injection effect and improving work efficiency.

[0106] After the liquid is injected, a metal sheet with a larger covering area than the injection hole 7 is used as a sealing metal sheet 71. The top surface of the sealing metal sheet 71 is laser welded at a predetermined distance around the outer circumference of the injection hole 7 to form a welding track surrounding the outside of the injection hole 7. In the welding track area, the metal of the contact surface between the sealing metal sheet 71 and the side wall 12 is melted and sealed to seal the injection hole 7.

[0107] As an illustration of this embodiment, the liquid injection hole 7 and the outer positive terminal plate 4 can be arranged on the same side wall 12 of the bottom shell 1.

[0108] As an illustration of this embodiment, a negative terminal plate 9 may be further provided on the side wall 12 of the bottom shell 1 and welded to the side wall 12 of the bottom shell 1 to facilitate the connection of an external power source.

[0109] As an illustration of this embodiment, another through hole can be further provided on the side wall 12 of the bottom shell 1, which is marked as a negative electrode through hole. A negative terminal plate 9 having an area larger than the negative electrode through hole covers the negative electrode through hole. Laser welding is performed from the top surface of the negative terminal plate 9 to melt and seal the adjacent metals of the negative terminal plate 9 and the side wall 12. The negative terminal plate 9 seals the negative electrode through hole, and the bottom end of the negative terminal plate 9 is exposed to the inside of the bottom shell 1 through the negative electrode through hole. The negative electrode of the battery cell is welded to the bottom end of the negative terminal plate 9 to achieve spot welding of the negative electrode.

[0110] As an illustration of this embodiment, one or more explosion-proof parts 10 may be provided at any position of the shell wall of the bottom shell 1 (or the cover plate 2), and the wall thickness of the position where the explosion-proof part 10 is located is thinner than the wall thickness of other positions of the bottom shell 1 (or the cover plate 2). For example, but not limited to, the explosion-proof part 10 is provided at the shell bottom 11 of the bottom shell 1, or provided on the cover plate 2 opposite to the shell bottom 11.

[0111] The thinned position of the explosion-proof portion 10 can be disposed on the outer surface of the battery for easy identification by the user; it can also be disposed on the inner surface of the battery.

[0112] The lithium-ion battery of this embodiment can be used in electronic products. The lithium-ion battery is installed in the power supply compartment of the electronic product, so that the positive and negative electrodes of the lithium-ion battery are respectively electrically connected to the positive and negative electrodes of the driving circuit of the electronic product. The battery is used as the power supply for the driving circuit to drive the circuit of the electronic product.

[0113] As an illustration of this embodiment, the shapes of the outer positive terminal plate 4 and the negative terminal plate 9 may be designed to be different, but not limited to, to improve the identification of the positive and negative electrodes and avoid reverse connection.

[0114] As an illustration of this embodiment, it is possible but not limited to setting a power contact opposite to the outer positive terminal plate 4 and negative terminal plate 9 of the battery in the bottom shell 1 in the power compartment, and setting a spring at the rear end of the power terminal. Through the elastic force, the power contact with the drive circuit is respectively pressed against the outer positive terminal plate 4 and negative terminal plate 9 of the battery in the bottom shell 1 with a certain pressure, so that the connection of the power supply is simple and convenient.

[0115] As an illustration of this embodiment, the outer shell composed of the bottom shell 1 and the cover plate 2 of this embodiment can be flexibly designed according to the shape of the power supply compartment of the electronic product. For example, when the power supply compartment has a pentagonal structure, the outer shell can be designed as a columnar structure with a closed figure having a pentagonal cross-section. Similarly, when the power supply compartment has other special-shaped structures, the outer shell of the battery is designed to be a matching special shape, which is conducive to making full use of the space in the power supply compartment and improving the volume energy density of the lithium-ion battery.

[0116] Embodiment 2.

[0117] See also Figure 9-20 .

[0118] The steel-shell lithium-ion battery of this embodiment includes a bottom shell 1, a cover plate 2, a battery cell (not shown in the figure, and the specific preparation thereof can refer to the prior art), an inner positive terminal plate 8, and an insulating member.

[0119] Similar to the embodiment, a second annular step 13 with a certain width is formed on the inner wall of the side wall 12, and the second annular step 13 is a bearing platform for the cover plate 2. A circle of the bottom surface of the cover plate 2 close to the outer edge is face to face with the top surface of the second annular step 13, and the end surface of the outer edge of the cover plate 2 is in contact with the inner wall of the side wall 12. The cover plate 2 is immersed and sealed on the inner side of the shell opening, and there is a seamless design between the cover plate 2 and the shell opening.

[0120] In this embodiment, the second positive electrode through hole 21 is designed on the cover plate 2 as an illustration, and the insulating rubber layer 85 serves as an insulating member. The insulating rubber layer 85 has a through hole with a hole diameter equal to or smaller than the second positive electrode through hole 21. The insulating rubber layer 85 is tightly attached to the inner surface of the cover plate 2, and the edge of the through hole in the insulating rubber layer 85 is flush with the edge of the second positive electrode through hole 21 of the cover plate 2. It is preferred that the insulating rubber layer 85 with a certain width is located in the second positive electrode through hole 21 of the cover plate, so as to provide better insulation spacing from the steel shell as the negative electrode cover plate 2.

[0121] A boss 84 having a diameter smaller than the diameter of the positive through hole of the cover plate 2 is provided on the top surface of the second end 82 of the inner positive terminal plate 8. The cross-sectional shape of the boss 84 is not limited, and may be circular, square, triangular, or quadrilateral, etc. The height of the boss 84 of the inner positive terminal plate 8 is equal to or greater than the sum of the thickness of the insulating rubber layer 85 and the cover plate 2, so that the boss 84 passes through the through hole of the insulating rubber layer 85 and the positive through hole of the cover plate 2 and is exposed on the outer surface of the cover plate 2, serving as the positive electrode of the lithium-ion battery for external connection.

[0122] Between the second end 82 of the inner positive terminal plate 8 provided with the boss 84 and the first end 81 is the current limiting position 83. At the current limiting position 83, the inner positive terminal plate 8 is integrally connected in series between the first end 81 and the second end 82. The cross section at the current limiting position 83 is much smaller than the cross section of the first end 81 and the second end 82, that is, the inner positive terminal plate 8 is greatly narrowed at the current limiting position 83. The positive electrode of the battery cell is connected to the bottom surface of the second end 82 of the inner positive terminal plate 8. When the current of the positive electrode is greater than the predetermined threshold value, the current limiting position 83 heats up and melts, disconnecting the current loop from the inside of the lithium-ion battery, realizing the strong current limiting protection of the lithium-ion battery, and improving the power safety of the lithium-ion battery.

[0123] As an illustration of this embodiment, the top surface of the boss 84 can be made flush with the top surface of the cover plate 2 , or the top surface of the boss 84 can be made slightly higher than the top surface of the cover plate 2 .

[0124] During preparation, the insulating rubber layer 85 and the inner positive terminal plate 8 are stacked on the bottom surface of the cover plate 2, and the stacked body is pressed by hot pressing equipment. Under the action of heat and pressure, the colloid on both surfaces of the insulating rubber layer 85 melts and is fully combined with the surfaces of the cover plate 2 and the inner positive terminal plate 8 facing it. After fixing for a predetermined time and cooling and shaping, the cover plate 2 with the inner positive terminal plate 8 preset is obtained as a preparation.

[0125] This embodiment uses a laminated lithium-ion battery cell, and the shapes of the pole pieces of the laminated battery cell are respectively consistent with the shape of the shell bottom 11 of the bottom shell 1, and the thickness of the laminated battery cell is the same or substantially the same as the height from the shell bottom 11 of the bottom shell 1 to the second annular step 13, so that the space in the cavity of the bottom shell 1 is fully utilized to improve the volume energy density of the lithium-ion battery.

[0126] Especially when applied to square batteries or batteries with special-shaped bottom shells 1, compared with cylindrical wound battery cells, the laminated lithium-ion battery using the above-mentioned solution can fully utilize the space in the shell and improve the volume energy density of the battery.

[0127] As can be seen from the above, the application of the technical solution of this embodiment has the following beneficial effects:

[0128] On the one hand, it is beneficial to improve the volume energy density of lithium-ion batteries;

[0129] On the other hand, compared with the soft-pack lithium-ion battery, the bottom shell 1 structure of this embodiment has better heat dissipation and is particularly suitable for fast charging and high current discharge;

[0130] Moreover, compared with soft-pack lithium-ion batteries, the lithium-ion batteries of this solution are easy to disassemble and recycle, easy to replace, and their application is more in line with environmental protection requirements.

[0131] In addition, the present embodiment sets a current limiting position 83 on the inner positive terminal plate 8 inside the lithium-ion battery, so that when the current is greater than a predetermined threshold, the current limiting position 83 generates heat and melts, thereby disconnecting the current loop from the inside of the lithium-ion battery, thereby achieving strong current limiting protection for the lithium-ion battery and improving the power safety of the lithium-ion battery.

[0132] In addition, in order to further improve the stability of the connection between the current limiting portion 83 and the second end portion 82 of the inner positive terminal plate 8, an adhesive layer is further provided between the top surface of the inner positive terminal plate 8 surrounding the boss 84 and the bottom surface of the insulating adhesive layer 85. The adhesive layer further reinforces and fixes the inner positive terminal plate 8 to the bottom surface of the insulating adhesive layer 85 to avoid detachment from the bottom surface of the insulating adhesive layer 85 and disconnection at the current limiting position 83, thereby causing a circuit breaker failure.

[0133] Embodiment three.

[0134] See also Fig.21 .

[0135] This embodiment provides another bottom shell 1 different from the first embodiment, and the differences mainly include:

[0136] A skirt 15 is formed on the side wall 12 at the folded end of the shell opening of the bottom shell 1, and the skirt 15 exceeds the outer surface of the side wall 12 of the bottom shell 1. The cover plate 2 is a flat plate with a width consistent with the pattern formed on the outer periphery of the skirt 15 of the bottom shell 1. The cover plate covers the shell opening of the bottom shell 1, and the outer edge is aligned with the outer edge of the skirt 15.

[0137] A vertical welding machine is used to weld along the edge of the top surface of the cover plate 2, and the metals of the two surfaces of the cover plate 2 and the skirt 15 that are in contact with each other are melted and fully sealed and bonded.

[0138] The outer positive terminal plate and the inner positive terminal plate on the side wall 12 of the bottom shell 1 are connected by a riveted structure similar to that in Embodiment 1.

[0139] The above-described implementation methods do not constitute a limitation on the protection scope of the technical solution. Any modification, equivalent replacement and improvement made within the spirit and principle of the above-described implementation methods shall be included in the protection scope of the technical solution.

Claims

1. A lithium ion battery, characterized in that: Including steel shell, battery body, inner positive terminal plate, insulating parts, A positive electrode through hole is provided on any shell wall of the steel shell, a through hole with a smaller diameter than the positive electrode through hole is provided on the insulating member, and the through hole of the insulating member is located inside the positive electrode through hole. The inner positive terminal plate is arranged on the inner wall of the steel shell through the insulating member, and the insulating member insulates and separates the steel shell and the inner positive terminal plate, and seals the positive through hole. The positive electrode of the battery cell is welded to the first end of the inner positive terminal plate. The top surface of the second end of the inner positive terminal plate is exposed from the through hole of the insulating member to the steel shell as the positive electrode of the lithium ion battery, or is connected to the positive electrode arranged outside the steel shell through the through hole of the insulating member. Between the first end and the second end of the inner positive terminal plate is a current limiting position with a cross-section smaller than that of the first end and the second end. The current flowing out from the positive electrode of the battery cell passes through the first end, the current limiting position, and the second end of the inner positive terminal plate in sequence. When the current is greater than or equal to a predetermined threshold, the current limiting position is blown.

2. The lithium-ion battery according to claim 1, characterized in that: Also includes rivets, outer positive terminal plate, The insulating member comprises an inner insulating set and an outer insulating film. The inner insulating set comprises: an integrated insulating collar and an insulating skirt, wherein the insulating skirt is formed by radially extending outward along the outer edge of the bottom end of the insulating collar by a predetermined width, the insulating skirt is closely attached to the inner wall of the steel shell, the insulating collar is sleeved in the positive through hole, and the end thereof extends out of the shell wall. The outer insulating film and the outer positive terminal plate are respectively provided with a through hole, and are collectively sleeved on the outer side of the insulating sleeve ring extending outside the steel shell. The outer insulating film is closely attached to the outer wall of the steel shell, and the outer positive terminal plate is closely attached to the top surface of the outer insulating film. The outer insulating film insulates and separates the outer positive terminal plate from the shell wall. The core of the rivet passes through the through hole of the second end of the inner positive terminal plate, the insulating sleeve, the outer insulating film, and the outer positive terminal plate in sequence from the inside to the outside. One head of the rivet is tightly against the bottom surface of the first end of the inner positive terminal plate, and the other head is tightly against the top surface of the outer positive terminal plate. The inner insulating set and the outer insulating film insulate and separate the shell wall from the rivet, the inner positive terminal plate and the outer positive terminal plate.

3. The lithium-ion battery according to claim 2, characterized in that: The top surface of the outer positive terminal plate is also provided with: a first annular step surrounding the through hole of the outer positive terminal plate, lower than the top surface of the outer positive terminal plate, and in a continuous and closed shape; The outer edge of the head of the rivet is tightly against the top surface of the first annular step.

4. The lithium-ion battery according to claim 1, characterized in that: The insulating member is an insulating rubber layer, the insulating rubber layer has a through hole with a hole diameter equal to or smaller than the positive electrode through hole, the insulating rubber layer is closely attached to the inner surface of the shell wall, and the through hole of the insulating rubber layer is located in the positive electrode through hole, A boss having a diameter smaller than that of the positive through hole is provided on the top surface of the second end of the inner positive terminal plate, and the boss passes through the through hole of the insulating rubber layer and is exposed outside the shell wall, serving as the positive electrode of the lithium-ion battery. The top surface of the inner positive terminal plate surrounding the boss is attached to the bottom surface of the insulating rubber layer. The positive electrode of the battery cell is welded to the bottom surface of the first end portion of the positive terminal plate.

5. The lithium-ion battery according to claim 4, characterized in that: An adhesive layer is provided between the top surface of the inner positive terminal plate surrounding the boss and the bottom surface of the insulating adhesive layer.

6. The lithium ion battery according to any one of claims 1 to 5, characterized in that: The steel shell comprises: The bottom shell comprises a shell opening, a side wall surrounding the shell opening and a shell bottom facing the shell opening, wherein a second annular step is provided on the inner wall near the shell opening, and the second annular step surrounds the inner wall to form a continuous closed ring. The outer edge of the bottom surface of the steel cover plate is in contact with the top surface of the second annular step, and the metals of the two surfaces are melted and sealed, and the cover plate seals the shell opening.

7. The lithium ion battery according to any one of claims 1 to 5, characterized in that: The steel shell comprises: The bottom shell comprises a shell opening, side walls surrounding the shell opening and a shell bottom facing the shell opening, wherein each of the side walls is folded outward at the shell opening to form a skirt that continuously surrounds the shell opening. The outer edge of the bottom surface of the steel cover plate is in contact with the top surface of the skirt of the bottom shell, and the metals of the two surfaces are melted and sealed to seal the shell opening.

8. The lithium-ion battery according to claim 7, characterized in that: At least one explosion-proof portion is also provided on at least any shell wall of the steel shell. The wall thickness at the location of the explosion-proof portion is thinner than the wall thickness of the steel shell and / or the cover plate.

9. The lithium-ion battery according to any one of claims 1 to 5, characterized in that: exist Any shell wall of the steel shell is also provided with an injection hole, and a sealing metal sheet is provided on the injection hole. The bottom surface of the sealing metal sheet is in contact with the outer surface of the shell wall outside the injection hole, and the metal of the adjacent surfaces is melted and sealed, and the sealing metal sheet seals the injection hole.

10. An electronic product, characterized in that: Including power supply compartment, A lithium-ion battery according to any one of claims 1 to 9 is arranged in the power supply compartment. The positive electrode and the negative electrode of the lithium ion battery are electrically connected to the positive electrode and the negative electrode of the driving circuit of the electronic product respectively.

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