Micro battery

Abstract

The present invention discloses a micro battery, which includes a housing and an electric core disposed within the housing. The electric core includes a first electrode assembly and a second electrode assembly with opposite polarities; the housing includes a first housing and a second housing. The first housing is inserted into the inner cavity of the second housing and is fixedly sealed with the second housing. The first housing and the second housing have an overlapping area. A first tab is led out from the first electrode assembly, and one end of the first tab is mechanically and electrically connected to the inner wall of the first housing located in the overlapping area. During the preparation process of this micro battery, the welding position of the first tab is located inside the housing. Even if the first housing is melted through, the second housing can still play a protective role and will not cause the risk of electrolyte leakage, which can greatly improve the yield rate and reduce the production cost.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and particularly to a micro battery. Background Art

[0002] Micro batteries are a type of batteries with a relatively small size and high energy density, which are widely used in various aspects of life, such as small portable electronic devices like electronic watches, Bluetooth headsets, hearing aids, etc.

[0003] As Figure 1 , a micro battery 4 in the related art is shown, which includes a metal shell 41 and an electric core 42 placed in the metal shell 41. One tab 43 of the electric core 42 is directly welded to the wall surface (the illustrated welding area 44) of the metal shell 41. However, during the preparation process, many factors including but not limited to current, surface cleanliness, etc. may cause the melting through of the metal shell 41, resulting in liquid leakage, which will reduce the yield rate and thus increase the production cost. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an improved micro battery.

[0005] The technical solution adopted by the present invention to solve its technical problem is: to construct a micro battery, including a shell and an electric core arranged in the shell. The electric core includes a first electrode assembly and a second electrode assembly with opposite polarities; the shell includes a first shell and a second shell. The first shell is inserted into the inner cavity of the second shell and is hermetically fixed to the second shell. The first shell and the second shell have an overlapping area;

[0006] The first electrode assembly leads out a first tab. One end of the first tab is mechanically and electrically connected to the inner wall of the first shell located in the overlapping area.

[0007] In some embodiments, the one end of the first tab is welded and fixed to the inner wall of the first shell located in the overlapping area.

[0008] In some embodiments, the part of the first shell located in the overlapping area is conductive, and the first electrode assembly is electrically connected to the first shell through the first tab.

[0009] In some embodiments, the first tab includes a current collector. One end of the current collector is fixed to the inner wall of the first shell located in the overlapping area;

[0010] Alternatively, the first tab includes a current collector and a conductive connecting piece. At least part of the conductive connecting piece is arranged on the inner wall of the first shell located in the overlapping area, and one end of the current collector is fixed to the conductive connecting piece.

[0011] In some embodiments, the overlapping area of the first housing and the second housing is 5%-99% of the height dimension of the outer housing.

[0012] In some embodiments, both the first housing and the second housing are cylindrical structures, and the outer diameter of the first housing is less than or equal to the inner diameter of the second housing;

[0013] The first housing includes an end wall and a ring-shaped peripheral wall extending from the periphery of the end wall; the second housing includes a bottom wall and a ring-shaped surrounding wall extending from the periphery of the bottom wall;

[0014] The outer wall surface of the ring-shaped peripheral wall and the inner wall surface of the ring-shaped surrounding wall overlap at least partially to form the overlapping area.

[0015] In some embodiments, the battery cell includes an isolation component, and the battery cell is formed by winding the first electrode component, the second electrode component, and the isolation component. A cavity is provided at the center of the battery cell;

[0016] A second tab is led out from the second electrode component.

[0017] In some embodiments, the first housing further includes an isolation sheet and a conductive sheet, and the end wall and the conductive sheet are insulated and sealed together through the isolation sheet;

[0018] The conductive sheet extends a first electrode lead-out body that passes through the cavity to be connected to the second tab.

[0019] In some embodiments, the outer housing further includes an insulating member disposed between the outer wall surface of the ring-shaped peripheral wall and the inner wall surface of the ring-shaped surrounding wall;

[0020] The bottom wall is conductive, and the bottom wall extends a second electrode lead-out body that passes through the cavity to be connected to the second tab.

[0021] In some embodiments, the second electrode lead-out body and the second housing are of an integral structure.

[0022] Implementing the present invention has the following beneficial effects: The micro battery of the present invention includes a housing and a battery cell disposed within the housing. The battery cell includes a first electrode assembly and a second electrode assembly with opposite polarities; the housing includes a first housing and a second housing. The first housing is inserted into the inner cavity of the second housing and is fixedly sealed with the second housing. The first housing and the second housing have an overlapping area. The first electrode assembly leads out a first tab, and one end of the first tab is mechanically and electrically connected to the inner wall of the first housing located in the overlapping area. During the preparation process of this micro battery, the welding position of the first tab is inside the housing. Even if the first housing is melted through, the second housing can still play a protective role and will not cause the risk of electrolyte leakage, which can greatly improve the yield rate and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the present invention, the present invention will be further described below in conjunction with the drawings and embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings. In the drawings:

[0024] Figure 1 is a simple schematic diagram of a micro battery in the related art;

[0025] Figure 2 is a structural schematic diagram of a micro battery in some embodiments of the present invention;

[0026] Figure 3 Figure 2 The front structure schematic diagram of the micro battery in;

[0027] Figure 4 is Figure 3 The sectional view of the micro battery along the line A-A in;

[0028] Figure 5 is Figure 4 The partial detail schematic diagram of the micro battery in;

[0029] Figure 6 is a structural schematic diagram of a micro battery in some other embodiments of the present invention;

[0030] Figure 7 is a structural schematic diagram of a micro battery in some other embodiments of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In order to have a clearer understanding of the technical features, objectives, and effects of the present invention, the specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientation or positional relationships indicated by terms such as "front", "rear", "upper", "lower", "left", "right", "longitudinal", "transverse", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail", etc. are based on the orientation or positional relationships shown in the accompanying drawings and are constructed and operated in a specific orientation. This is only for the convenience of describing the present technical solution and does not indicate that the indicated device or element must have a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0032] It should also be noted that, unless otherwise clearly specified and limited, terms such as "installed", "connected", "joined", "fixed", "set", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located above the other element, or there may also be one or more intermediate elements. Terms such as "first", "second", "third", etc. are only for the convenience of describing the present technical solution and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third", etc. can explicitly or implicitly include one or more of such features. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] Please refer to Figures 2 to 4 , which is a micro battery in some embodiments of the present invention. It includes a housing 1 and an electric core 2 disposed inside the housing 1. The electric core 2 includes a first electrode assembly 21 and a second electrode assembly 22 with opposite polarities. Among them, the housing 1 includes a first housing 11 and a second housing 12. The first housing 11 is inserted into the inner cavity of the second housing 12 and is hermetically fixed to the second housing 12. The first housing 11 and the second housing 12 have an overlapping area. The first electrode assembly 21 leads out a first tab, and one end of the first tab is mechanically and electrically connected to the inner wall of the first housing 11 located in the overlapping area.

[0034] It can be understood that during the preparation process of the micro battery, the welding position of the first tab is inside the housing. Even if the first housing 11 is melted through, the second housing 12 can still play a protective role and will not cause the risk of electrolyte leakage, which can greatly improve the yield rate and reduce the production cost.

[0035] In some embodiments, the micro-battery can be a lithium-ion button battery, which can be generally flat cylindrical. In some embodiments, the height of the micro-battery can be 0.1-0.9 times its outer diameter, for example, 0.25-0.7 times, and preferably, it can be 0.5 times. Of course, in other embodiments, the micro-battery can also be in other shapes such as square columnar, elliptical columnar, etc.

[0036] In some embodiments, a sealed accommodation space is formed inside the outer shell 1, and the battery cell 2 is disposed inside the accommodation space and can be coaxially arranged with the outer shell 1.

[0037] In some embodiments, both the first shell 11 and the second shell 12 are cylindrical structures with an opening, such as a circular cylindrical structure. The outer diameter of the first shell 11 is less than or equal to the inner diameter of the second shell 12, so that the first shell 11 can be inserted into the second shell 12. Among them, the first shell 11 and the second shell 12 can be fixed together by laser welding or extrusion sealing. When laser welding is used, the welding position can be Figure 3 the a position shown.

[0038] Furthermore, the first shell 11 includes an end wall 111 and a circular peripheral wall 112 extending from the periphery of the end wall 111; the end wall 111 can be in the shape of a circular flat plate, or an arched structure 1111 is provided at the connection between the end wall 111 and the circular peripheral wall 112. In some embodiments, the end wall 111 and the circular peripheral wall 112 can be conductive, and they can be made of metal conductive materials, such as materials that can be laser welded, such as stainless steel, aluminum, iron, etc.

[0039] The second shell 12 can include a bottom wall 121 and a circular surrounding wall 122 extending from the periphery of the bottom wall 121. The outer wall surface of the circular peripheral wall 112 and the inner wall surface of the circular surrounding wall 122 at least partially overlap to form an overlapping area. Since the first shell 11 is inserted into the second shell 12, the area enclosed by the part of the circular peripheral wall 112 located inside the second shell 12 is the overlapping area. It can be understood that the circular peripheral wall 112 can be partially or entirely placed inside the second shell 12. In some embodiments, the second shell 12 can be conductive, such as it can be made of metal conductive materials, such as materials that can be laser welded, such as stainless steel, aluminum, iron, etc. Among them, the material of the second shell 12 can be the same as or different from the material of the first shell 11.

[0040] Preferably, the overlapping area of the first shell 11 and the second shell 12 is 5%-99% of the height dimension of the outer shell 1, for example, it can be 20%-80%.

[0041] In some embodiments, a step portion 1221 is provided on the inner periphery of the annular wall 122, the bottom end of the annular wall 112 abuts against the upper surface of the step portion 1221, and the inner wall surface of the annular wall 112 can be flush with the inner wall surface of the annular wall 122, so that the overall structure of the shell 1 is neat, which is convenient for the subsequent assembly and use of the micro battery, and reduces the battery installation space required for the electronic device.

[0042] In some embodiments, one end of the first tab is welded to the inner wall of the first shell 11 in the overlapping region. Preferably, the portion of the first shell 11 in the overlapping region is conductive, and the first electrode assembly 21 is electrically connected to the first shell 11 through the first tab.

[0043] like Figures 4 to 5 As shown, in some embodiments, the first electrode tab may include a current collector 211 and a conductive connector 212. The conductive connector 212 is at least partially provided on the inner wall of the first shell 11 in the overlapping region, and one end of the current collector 211 is fixed to the conductive connector 212. The conductive connector 212 may be fixed to the inner wall surface of the annular circumferential wall 122 by laser welding, and its welding position may be position b, while the current collector 211 may be fixed to the wall surface of the conductive connector 212 on the side away from the annular circumferential wall 122 by laser welding, and its welding position may be position c, thereby electrically connecting the first electrode assembly 21 to the first shell 11. Preferably, the welding position of the first shell 11 and the second shell 12 is staggered with the welding position of the first electrode tab. In this embodiment, position a may be in the area above position b, and position c may be in the area below position b.

[0044] like Figure 6 As shown, in other embodiments, the first tab includes a current collector 211, one end of which is fixed to the inner wall of the first housing 11 in the overlapping region. The current collector 211 may be fixed to the inner wall surface of the annular circumferential wall 112 in the overlapping region by laser welding, and the welding position may be position d. It is understood that the structure and welding position of the first tab can be appropriately adjusted according to needs and are not specifically limited here.

[0045] In some embodiments, the first housing 11 further includes an isolation sheet 113 and a conductive sheet 114 , and the end wall 111 and the conductive sheet 114 are insulated and sealed from each other via the isolation sheet 113 .

[0046] The spacer 113 is disposed between the end wall 111 and the conductive sheet 114 to insulate the end wall 111 and the conductive sheet 114. The thickness of the end wall 111, the spacer 113, and the conductive sheet 114 may be between 0.02 mm and 1 mm, preferably between 0.1 mm and 0.25 mm.

[0047] In some embodiments, the conductive sheet 114 is a circular metal sheet, and the spacer sheet 113 is a circular plastic sheet, preferably a laser-fusible plastic sheet. The end wall 111, the spacer sheet 113, and the conductive sheet 114 can be joined together by laser welding. In other embodiments, the conductive sheet 114 is not limited to being circular, and can also be square, oval, or other shapes. The surfaces of the end wall 111, the conductive sheet 114, and the spacer sheet 113 that are joined can be pre-treated to form a plurality of grooves. After laser welding, a part of the spacer sheet 113 is melted into the plurality of grooves, making the joint tighter. In other embodiments, the end wall 111, the spacer sheet 113, and the conductive sheet 114 can also be joined together by ultrasonic welding, nano-injection molding, or glue bonding. In still other embodiments, the spacer sheet 113 can also be made of rubber, TPE, or other insulating materials.

[0048] In some embodiments, the battery cell 2 may further include a separator assembly. The battery cell 2 is formed by winding a first electrode assembly 21, a second electrode assembly 22, and the separator assembly. The polarities of the first electrode assembly 21 and the second electrode assembly 22 are opposite. For example, the first electrode assembly 21 is the negative electrode, and the second electrode assembly 22 is the positive electrode; or the first electrode assembly 21 is the positive electrode, and the second electrode assembly 22 is the negative electrode.

[0049] In some embodiments, the battery cell 20 can be cylindrical, with a cavity formed longitudinally inside. The second electrode assembly 22 has a second tab 221 led out, and the conductive sheet 114 extends an electrode lead-out body 115 that passes through the cavity to connect to the second tab 221. Preferably, the second tab 221 is led out from the lower end of the side of the second electrode assembly 22 away from the end wall 111. The middle part of the conductive sheet 114 extends downward to form an electrode lead-out body 115 that passes through the cavity to connect to the second tab 221. The conductive sheet 114 and the second tab 221 can be located on both sides of the cavity respectively. Preferably, an insulating layer 3 is provided on the side of the bottom wall 121 facing the second tab 221 to prevent the second tab 221 from connecting to the second housing 12.

[0050] Preferably, lead-out holes for the electrode lead-out body 115 to pass through can also be formed on the end wall 111 and the spacer sheet 113. The lead-out holes can communicate with the cavity and coincide with the central axis of the cavity. The lead-out holes can be opened in the middle parts of the end wall 111 and the spacer sheet 113. The central axes of the end wall 111, the spacer sheet 113, the conductive sheet 114, and the lead-out holes can all coincide with the central axis of the second housing 12.

[0051] In some embodiments, the battery cell 2 can be made in the form of a spiral winding. Preferably, the first electrode assembly 21 and the second electrode assembly 22 each include at least one conductive metal sheet, and the isolation assembly includes at least one insulating isolation sheet. After the first electrode assembly 21, the isolation assembly, and the second electrode assembly 22 are stacked in sequence and wound around a rod-shaped core, the core is withdrawn to form a cavity with its central axis coinciding with the central axis of the battery cell 2. Of course, the battery cell 2 can be a wound body or a laminated structure.

[0052] In some embodiments, the conductive sheet 114 and the first electrode lead-out body 115 can be an integral structure, and its cross-section is generally a T-shaped structure. In this embodiment, the first electrode lead-out body 115 and the conductive sheet 114 that is a part of the first housing 11 are integrally formed, and can be formed into an integral structure by means such as casting, forging, cutting, or laser processing. The conductive sheet 114 and the first electrode lead-out body 115 being an integral structure reduces the processing procedures of the first electrode lead-out body 115 and the first housing 11 in the related art, can improve production efficiency, and effectively reduce production costs. At the same time, this integral structure is beneficial to the miniaturization of the button battery.

[0053] In some embodiments, the first electrode lead-out body 115 is respectively connected to the second electrode assembly 22 and the conductive sheet 114, and it can include a first electrode portion connected to the conductive sheet 114 and a second electrode portion connected to the second electrode assembly 22. The first electrode portion is a rigid column, and the columnar structure can facilitate reducing the size of the first electrode portion and the size of the lead-out hole for the first electrode portion to pass through, and is convenient for the connection operation between the first electrode portion and the conductive sheet 114.

[0054] In addition, after the rigid first electrode portion is fixed to the end wall 111 by means such as welding, it can also play a role in fixing the battery cell 2. The upper end of the first electrode portion 2 passes through the lead-out hole and is connected to the conductive sheet 114, and there is a gap between the outer peripheral surface of the first electrode portion and the hole wall of the lead-out hole to ensure that the first electrode portion passes through the end wall 111 insulatedly. In some embodiments, the cross-sectional shape of the first electrode portion corresponds to the cross-sectional shape of the lead-out hole, and the cross-sectional dimension of the first electrode portion is smaller than the cross-sectional dimension of the lead-out hole, which is beneficial to further reducing the size of the first electrode portion and the lead-out hole.

[0055] In this embodiment, the lead-out hole is a round hole, the first electrode portion is cylindrical, and the outer diameter of the first electrode portion is smaller than the aperture of the lead-out hole. In some embodiments, the outer diameter of the first electrode portion can be 0.8 - 3 mm. In other embodiments, the cross-section of the lead-out hole can also be in other regular or irregular shapes such as an ellipse, a square, etc. Correspondingly, the cross-section of the first electrode portion can also be in other regular or irregular shapes such as an ellipse, a square, etc. In still other embodiments, the cross-sectional shape of the first electrode portion and the cross-sectional shape of the lead-out hole may not be correspondingly arranged. For example, the cross-sectional shape of the lead-out hole is a square, and the cross-sectional shape of the first electrode portion is a circle.

[0056] The second electrode portion can be integrally formed with the second electrode assembly 22. In this case, both the second electrode portion and the second electrode assembly 22 are rigid. Alternatively, the second electrode portion 312 and the second electrode assembly 22 can also be separately formed and then combined together by means such as welding. In this case, the second electrode portion can also be flexible, which is convenient for leading out from the battery cell 2 and can avoid damaging the battery cell 2 due to collisions or the like.

[0057] In still other embodiments, the second electrode portion can be in the shape of a thin sheet, and the sheet-shaped second electrode portion is convenient for connecting with the sheet-shaped second tab 221. Further, the central axis of the second electrode portion can coincide with the central axis of the first electrode portion, and the thickness of the second electrode portion can be smaller than the outer diameter of the first electrode portion.

[0058] As Figure 7 shown, in still other embodiments, the housing 1 further includes an insulating member 13 provided between the outer wall surface of the annular peripheral wall 112 and the inner wall surface of the annular surrounding wall 122. The insulating member 13 can have a certain thickness and can be made of a soft rubber material such as silicone. The insulating member 13 covers the overlapping area. The insulating member 13 can be adhered to the outer wall surface of the first housing 11 by an adhesive such as glue or by fusion welding. Further, the lower end of the insulating member 13 can wrap the end of the annular peripheral wall 112 facing the bottom wall 121 to achieve insulation between the first housing 11 and the second housing 12. The open end of the second housing 12 can be hermetically bonded to the first housing 11 through the insulating member 13 by mechanical pressing.

[0059] Further, the bottom wall 121 is electrically conductive, and a second electrode lead body 123 extending through the cavity and connected to the second tab 221 is provided on the bottom wall 121. Preferably, a second tab 221 is led out from a side of the second electrode assembly 22 away from the bottom wall 121, and a second electrode lead body 115 extending through the cavity and connected to the second tab 221 is upwardly extended from the middle of the bottom wall 121. A welding area is formed at the connection between the second electrode lead body 115 and the second tab 221, and the second electrode lead body 115 and the second tab 221 can be connected together by laser welding. Thus, the welding positions of the structure of the micro-battery are all inside the housing 1.

[0060] Further, an insulating layer 3 is provided on the surface of the end wall 111 facing the second tab 221 to insulate the second tab 221 from the first housing 11. Preferably, the second electrode lead body 123 can be an integral structure with the second housing 12.

[0061] Both the first housing 11 and the second housing 12 are electrically conductive. The first housing 11 can form a positive-polarity structure, and the second housing 12 can form a negative-polarity structure, or the first housing 11 can form a negative-polarity structure, and the second housing 12 can form a positive-polarity structure.

[0062] It can be understood that the above embodiments only represent the preferred embodiments of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention; it should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can also be made, which all belong to the protection scope of the present invention; therefore, all equivalent transformations and modifications made to the scope of the claims of the present invention should fall within the scope covered by the claims of the present invention.

Claims

1. A micro battery, comprising a housing (1) and an electric core (2) disposed within the housing (1), the electric core (2) including a first electrode assembly (21) and a second electrode assembly (22) with opposite polarities; characterized in that, The outer shell (1) includes a first housing (11) and a second housing (12). The first housing (11) is inserted into the inner cavity of the second housing (12) and is fixedly sealed with the second housing (12). The first housing (11) and the second housing (12) have an overlapping area. The first electrode assembly (21) leads out a first tab. One end of the first tab is mechanically and electrically connected to the inner wall of the first housing (11) located in the overlapping area. Both the first housing (11) and the second housing (12) are cylindrical structures. The outer diameter of the first housing (11) is less than or equal to the inner diameter of the second housing (12). The first housing (11) includes an end wall (111) and an annular peripheral wall (112) extending from the periphery of the end wall (111). The second housing (12) includes a bottom wall (121) and an annular surrounding wall (122) extending from the periphery of the bottom wall (121). The outer wall surface of the annular peripheral wall (112) and the inner wall surface of the annular surrounding wall (122) at least partially overlap with each other to form the overlapping area. The battery cell (2) includes an isolation component. The battery cell (2) is formed by winding the first electrode assembly (21), the second electrode assembly (22), and the isolation component. A cavity is provided at the center of the battery cell (2). The second electrode assembly (22) leads out a second tab (221). The first housing (11) further includes an isolation sheet (113) and a conductive sheet (114). The end wall (111) and the conductive sheet (114) are insulated and sealed together through the isolation sheet (113). The conductive sheet (114) extends a first electrode lead-out body (115) passing through the cavity to be connected to the second tab (221). The outer shell (1) further includes an insulating member (13) provided between the outer wall surface of the annular peripheral wall (112) and the inner wall surface of the annular surrounding wall (122). The bottom wall (121) is conductive. The bottom wall (121) extends a second electrode lead-out body (123) passing through the cavity to be connected to the second tab (221).

2. The micro battery according to claim 1, characterized in that, The said one end of the first tab is welded and fixed to the inner wall of the first housing (11) located in the overlapping area.

3. The micro battery according to claim 2, wherein, The part of the first housing (11) located in the overlapping area is conductive. The first electrode assembly (21) is electrically connected to the first housing (11) through the first tab.

4. The micro battery according to claim 1, characterized in that, The first tab includes a current collector (211). One end of the current collector (211) is fixed to the inner wall of the first housing (11) located in the overlapping area. Alternatively, the first tab includes a current collector (211) and a conductive connecting member (212). The conductive connecting member (212) is at least partially disposed on the inner wall of the first housing (11) located in the overlapping area. One end of the current collector (211) is fixed to the conductive connecting member (212).

5. The micro battery according to claim 1, wherein The overlapping area of the first housing (11) and the second housing (12) is 5% - 99% of the height dimension of the outer housing (1).

6. The micro battery according to claim 1, characterized in that, The second electrode lead-out body (123) and the second housing (12) are of an integral structure.

Images