Secondary lithium batteries and electronic products

Abstract

The present invention discloses a secondary lithium battery and an electronic product, wherein the secondary lithium battery includes a bottom shell, a sealing complex, and a battery cell; the sealing complex includes a stacked sealing welding layer, an insulating sealing layer, and a waterproof conductive layer; the sealing welding layer and the portion of the annular side wall adjacent to the sealing welding layer are fused together to form a seal; the circuit board assembly has an input board surface and an output board surface disposed opposite each other, the input board surface having an input positive electrode and an input negative electrode, and the output board surface having an output positive electrode and an output negative electrode; the circuit board assembly has a first connecting circuit and a second connecting circuit; a vertical conductive adhesive layer is disposed between the input board surface and the side of the sealing complex facing away from the internal receiving cavity; the circuit board assembly has a first mating structure, and the bottom shell has a second mating structure, the first mating structure and the second mating structure being configured to mate with the outer shell of the electronic product. The technical solution of the present invention is conducive to improving the safety performance of secondary lithium batteries.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a secondary lithium battery and an electronic product. Background Art

[0002] Existing button batteries have a battery shell composed of a positive electrode shell and a negative electrode shell. The positive and negative electrode shells require insulation to prevent short circuits in the button battery. Related technologies achieve insulation by nesting the positive and negative electrode shells together, with an insulating film between them. Before the battery is installed in a product, the positive and negative electrodes need to be welded to each end to ensure stable power supply for electronic products. Because the battery shell is relatively thin, the welding process can easily damage the shell, seriously affecting the battery's service life and safety. Summary of the Invention

[0003] The main purpose of the present invention is to provide a secondary lithium battery and an electronic product, aiming to solve the problem of how to improve the safety of the battery.

[0004] To achieve the above-mentioned object, the secondary lithium battery proposed in the present invention includes a bottom shell, a sealing complex and a battery cell, wherein the bottom shell and the sealing complex form an internal receiving cavity, and the battery cell is placed in the internal receiving cavity;

[0005] The sealing composite body comprises a sealing welding layer, an insulating sealing layer and a waterproof conductive layer which are stacked;

[0006] One of the electrodes of the battery cell is electrically connected to the waterproof conductive layer, and the other electrode is electrically connected to the sealing welding layer or the bottom shell;

[0007] The bottom shell includes a circular or elliptical bottom and an annular side wall extending toward the sealing complex;

[0008] The sealing welding layer and the portion of the annular side wall close to the sealing welding layer are fused together to form a seal;

[0009] The sealing welding layer is provided with an avoidance hole to expose part of the waterproof conductive layer;

[0010] The secondary lithium battery further comprises:

[0011] A circuit board assembly having an input board surface and an output board surface disposed opposite to each other, the input board surface having an input positive electrode and an input negative electrode, and the output board surface having an output positive electrode and an output negative electrode; the circuit board assembly having a first connecting circuit and a second connecting circuit, the first connecting circuit connecting the input positive electrode and the output positive electrode, and the second connecting circuit connecting the input negative electrode and the output negative electrode;

[0012] A vertical conductive adhesive layer is provided between the input plate surface and the side of the sealing composite body facing away from the internal receiving cavity, so as to connect the input positive electrode and the waterproof conductive layer, and connect the input negative electrode and the sealing welding layer;

[0013] The circuit board assembly has a first mating structure, and the bottom shell has a second mating structure. The first mating structure and the second mating structure are configured to cooperate with the outer shell of the electronic product so that the sealing complex and the input board surface extrude the vertical conductive adhesive layer, so that the vertical conductive adhesive layer conducts the input positive electrode and the waterproof conductive layer, and conducts the input negative electrode and the sealing welding layer.

[0014] Optionally, the electronic product includes a functional circuit board, and the output board is arranged to face the functional circuit board.

[0015] Optionally, the housing includes a front shell and a rear shell, and the functional circuit board is installed in the front shell;

[0016] The first matching structure includes a supporting edge, which is an edge of the output plate surface; a supporting step extending along the circumference of the front shell is provided in the front shell corresponding to the output plate surface, and the supporting step is configured to support the supporting edge of the output plate surface; and / or,

[0017] The second matching structure includes a supporting bottom, and a supporting boss is provided in the rear shell corresponding to the supporting bottom. The supporting boss is located in the middle of the rear shell; the supporting boss is configured to support the supporting bottom.

[0018] Optionally, the housing includes a front housing and a rear housing;

[0019] The second matching structure includes a supporting bottom, and a supporting step extending along the circumference of the front shell is provided in the front shell corresponding to the supporting bottom, and the supporting step is configured to support the bottom of the bottom shell; and / or,

[0020] The first matching mechanism includes a supporting edge, and a supporting boss is provided in the rear shell corresponding to the panel assembly, and the supporting boss is located at the bottom of the rear shell; the supporting boss is configured to support the output plate surface.

[0021] Optionally, the secondary lithium battery further includes an insulating buffer pad, and the insulating buffer pad is disposed on the supporting boss.

[0022] Optionally, the thickness of the vertical adhesive layer is 0.1 mm to 0.3 mm; and / or,

[0023] The thickness of the circuit board assembly is 12.5 microns to 6.4 mm.

[0024] Optionally, the circuit board assembly has a voltage stabilizing circuit, and the voltage stabilizing circuit is connected in series with the first connecting circuit and / or the second connecting circuit.

[0025] Optionally, the circuit board assembly has an overload protection circuit, and the overload protection circuit is connected in series with the first connection circuit and / or the second connection circuit.

[0026] The present application further proposes an electronic product, the electronic product comprising a device body and a secondary lithium battery, the battery being electrically connected to the device body to provide power to the device body;

[0027] The secondary lithium battery comprises a bottom shell, a sealing complex and a battery cell, wherein the bottom shell and the sealing complex form an internal receiving cavity, and the battery cell is placed in the internal receiving cavity;

[0028] The sealing composite body comprises a sealing welding layer, an insulating sealing layer and a waterproof conductive layer which are stacked;

[0029] One of the electrodes of the battery cell is electrically connected to the waterproof conductive layer, and the other electrode is electrically connected to the sealing welding layer or the bottom shell;

[0030] The bottom shell includes a circular or elliptical bottom and an annular side wall extending toward the sealing complex;

[0031] The sealing welding layer and the portion of the annular side wall close to the sealing welding layer are fused together to form a seal;

[0032] The sealing welding layer is provided with an avoidance hole to expose part of the waterproof conductive layer;

[0033] The secondary lithium battery further comprises:

[0034] A circuit board assembly having an input board surface and an output board surface disposed opposite to each other, the input board surface having an input positive electrode and an input negative electrode, and the output board surface having an output positive electrode and an output negative electrode; the circuit board assembly having a first connecting circuit and a second connecting circuit, the first connecting circuit connecting the input positive electrode and the output positive electrode, and the second connecting circuit connecting the input negative electrode and the output negative electrode;

[0035] A vertical conductive adhesive layer is provided between the input plate surface and the side of the sealing composite body facing away from the internal receiving cavity, so as to connect the input positive electrode and the waterproof conductive layer, and connect the input negative electrode and the sealing welding layer;

[0036] The circuit board assembly has a first mating structure, and the bottom shell has a second mating structure. The first mating structure and the second mating structure are configured to cooperate with the outer shell of the electronic product so that the sealing complex and the input board surface extrude the vertical conductive adhesive layer, so that the vertical conductive adhesive layer conducts the input positive electrode and the waterproof conductive layer, and conducts the input negative electrode and the sealing welding layer.

[0037] Optionally, the device body includes an earphone, the earphone includes a shell and a speaker, the shell includes a front shell and a rear shell, the speaker is arranged in the front shell, and the secondary lithium battery is located on the side of the speaker facing away from the earphone outlet.

[0038] In the present application, by providing a first matching structure on the circuit board assembly and a second matching structure on the bottom shell, after the secondary lithium battery is installed in the shell, an extrusion force can be generated between the circuit board assembly and the sealing complex, so that the vertical conductive adhesive layer provided therein is squeezed, so that the input positive electrode and the waterproof conductive layer are connected by the vertical conductive adhesive layer, and the input negative electrode and the sealing welding layer are connected by the vertical conductive adhesive layer; that is, the positive electrode of the battery cell is connected to the output positive electrode through the waterproof conductive layer, the vertical conductive adhesive layer, the input positive electrode, the first connecting circuit in sequence, and the negative electrode of the battery cell is connected to the output negative electrode through the sealing welding layer, the vertical conductive adhesive layer, the input negative electrode, the second connecting circuit in sequence; the positive electrode and the negative electrode of the battery cell are extended to the output board surface of the circuit board assembly;

[0039] In this way, when the secondary lithium battery is connected to the circuit of the product, the wires can be directly welded to the output positive electrode and the output negative electrode of the output board, avoiding the direct welding of the wires to the sealing complex, greatly reducing the difficulty of welding, improving the reliability of welding, and avoiding damage to the sealing complex caused by direct welding, thereby greatly improving the safety of the battery; at the same time, the sealing complex can be separated from the vertical conductive adhesive layer, that is, the secondary lithium battery can be disassembled into a part consisting of the circuit board assembly and the vertical conductive adhesive layer, and another part consisting of the bottom shell, the sealing complex and the battery cell. No matter which part fails, the other part can be completely separated and can be reused, which is conducive to improving the utilization rate of materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0041] Figure 1 This is a schematic structural diagram of an embodiment of a secondary lithium battery of the present invention;

[0042] Figure 2 Schematic diagram of the explosion structure of the bottom shell and sealing complex of the secondary lithium battery of the present invention;

[0043] Figure 3 for Figure 2 Schematic diagram of the structure from one perspective after assembly;

[0044] Figure 4 for Figure 3 Schematic diagram of the cross-sectional structure at AA in the middle;

[0045] Figure 5 for Figure 4 The enlarged structural diagram of an embodiment at M in the middle;

[0046] Figure 6 for Figure 4 An enlarged structural diagram of an embodiment of a sealing welding layer at N locations;

[0047] Figure 7 for Figure 2 Schematic diagram of the explosion structure of the middle sealing complex;

[0048] Figure 8 for Figure 1 Schematic diagram of the structure of the middle bottom shell;

[0049] Figure 9 for Figure 8 Schematic diagram of the cross-sectional structure at the middle BB;

[0050] Figure 10 for Figure 9 The enlarged structural diagram of an embodiment at O ​​in the middle;

[0051] Figure 11 for Figure 1 Schematic diagram of the explosion structure;

[0052] Figure 12 It is a structural schematic diagram of an embodiment of a circuit board assembly;

[0053] Figure 13 A schematic diagram of an exploded structure of an embodiment of a circuit board assembly and a vertical conductive adhesive layer;

[0054] Figure 14 A schematic diagram of an exploded structure of another embodiment of a circuit board assembly and a vertical conductive adhesive layer;

[0055] Figure 15 for Figure 1 A structural diagram from another perspective;

[0056] Figure 16 for Figure 15 Schematic diagram of the cross-section structure at CC;

[0057] Figure 17 for Figure 16 The enlarged structural diagram of an embodiment at P in the middle;

[0058] Figure 18 for Figure 16 The enlarged structural diagram of an embodiment at Q in the middle;

[0059] Figure 19 This is a schematic structural diagram of an electronic product according to an embodiment of the present invention;

[0060] Figure 20 This is a schematic diagram of the explosion structure of an electronic product according to an embodiment of the present invention;

[0061] Figure 21 This is a schematic diagram of the explosion structure of another embodiment of the electronic product of the present invention;

[0062] Figure 22 for Figure 19 Structural diagram from another perspective;

[0063] Figure 23 for Figure 22 A schematic structural diagram of an embodiment of DD;

[0064] Figure 24 for Figure 23 The enlarged structural diagram of an embodiment is shown at R in the figure.

[0065]

[0066] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0067] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0068] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0069] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their 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 at least one of such features. In addition, the meaning of "and / or" appearing in the full text is to include three parallel solutions. Taking "A and / or B as an example", it includes solution A, or solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0070] The present invention provides a secondary lithium battery, such as a small button cell, mobile phone battery, or toroidal battery. The secondary lithium battery is used in electronic products that have a housing within which the secondary lithium battery is installed. The following details the battery's structure and operating principle.

[0071] Reference Figures 1 to 18 , a secondary lithium battery, characterized in that,

[0072] The secondary lithium battery includes a bottom shell 200, a sealing complex 100 and a battery cell. The bottom shell 200 and the sealing complex 100 form an internal receiving cavity, and the battery cell is placed in the internal receiving cavity.

[0073] The sealing composite 100 includes a sealing welding layer 110, an insulating sealing layer and a waterproof conductive layer 130 which are stacked.

[0074] One of the electrodes of the battery cell is electrically connected to the waterproof conductive layer 130 , and the other electrode is electrically connected to the sealing welding layer 110 or the bottom shell 200 ;

[0075] The bottom shell 200 includes a circular or elliptical bottom and an annular sidewall extending toward the sealing complex 100;

[0076] The sealing welding layer 110 and the portion of the annular side wall close to the sealing welding layer 110 are fused together to form a seal;

[0077] The sealing welding layer 110 is provided with an avoidance hole 111 to expose a portion of the waterproof conductive layer 130;

[0078] The secondary lithium battery further comprises:

[0079] A circuit board assembly 500 includes an input board surface 550 and an output board surface 560 disposed opposite each other. The input board surface 550 includes an input positive electrode 510 and an input negative electrode 520, and the output board surface 560 includes an output positive electrode 530 and an output negative electrode 540. The circuit board assembly 500 includes a first connecting circuit and a second connecting circuit. The first connecting circuit connects the input positive electrode 510 and the output positive electrode 530, and the second connecting circuit connects the input negative electrode 520 and the output negative electrode 540.

[0080] A vertical conductive adhesive layer 700 is provided between the input plate surface 550 and the side of the sealing composite body 100 facing away from the internal receiving cavity, so as to connect the input positive electrode 510 and the waterproof conductive layer 130, and to connect the input negative electrode 520 and the sealing welding layer 110;

[0081] The circuit board assembly has a first mating structure, and the bottom shell 200 has a second mating structure. The first mating structure and the second mating structure are configured to cooperate with the outer shell 610 of the electronic product 600 so that the sealing complex 100 and the input board surface extrude the vertical conductive adhesive layer, so that the vertical conductive adhesive layer conducts the input positive electrode and the waterproof conductive layer, and conducts the input negative electrode and the sealing welding layer 110.

[0082] Specifically, in this embodiment, the bottom housing 200 and the sealing assembly 100 can have various shapes, and together they form a receiving cavity. The sealing assembly 100 is sealed to the bottom housing 200 by welding. The overall housing of a secondary lithium battery can have many shapes, such as a round, oval, or rectangular shape. A round shape is used as an example for the description. Preferably, to reduce the thickness of the battery housing and increase the battery life, portions of the bottom housing 200 and the sealing assembly 100 in this application are made of metal. In some embodiments, to improve welding performance, the bottom housing 200 and the sealing welding layer 110 are made of the same metal. The metal material can be stainless steel, specifically 304 stainless steel or 316 stainless steel. Specifically, the sealing welding layer 110 and the waterproof conductive layer 130 of the sealing assembly 100 are both supported by metal. The insulating sealing layer 120 is an insulating adhesive layer that not only insulates the sealing welding layer 110 from the waterproof conductive layer 130 but also tightly connects them together.

[0083] The battery cell 300 has a positive electrode and a negative electrode, wherein the positive electrode is electrically connected to the waterproof conductive layer 130 ; the negative electrode is electrically connected to the sealing welding layer 110 , or alternatively, the negative electrode is electrically connected to the bottom casing 200 . Of course, in some embodiments, the negative electrode can also be electrically connected to the waterproof conductive layer 130 , and the positive electrode can be electrically connected to the sealing welding layer 110 , or alternatively, the positive electrode is electrically connected to the bottom casing 200 . The following embodiments illustrate the electrical connection between the positive electrode of the battery cell and the waterproof conductive layer. While there are many ways to achieve electrical connection, this embodiment uses welding to extend the electrodes to the desired connection location as an example.

[0084] The sealing welding layer 110 can have various shapes, such as a circular ring with a clearance hole 111 in the center. The waterproof conductive layer 130 can have various shapes, such as a circular ring. The sealing welding layer 110, the insulating sealing layer 120, and the waterproof conductive layer 130 are stacked in sequence. The insulating sealing layer 120 can have various shapes, such as a circular ring. It fills the stacked area of ​​the sealing welding layer 110 and the waterproof conductive layer 130, completely isolating the sealing welding layer 110 from the waterproof conductive layer 130. By setting the stacked area of ​​the insulating sealing layer 120 and the sealing welding layer 110 to at least 0.2 times the area of ​​the sealing welding layer 110, the connection area between the insulating sealing layer 120 and the sealing welding layer 110 is sufficiently large, and the connection strength between the two layers is sufficient to support subsequent processes (such as the process of injecting electrolyte into the battery, which requires a pressure differential between the inside and outside of the battery to allow the electrolyte to enter the receiving cavity under the action of the pressure differential) and the connection strength required during operation. At the same time, by setting the stacking area of ​​the insulating sealing layer 120 and the sealing welding layer 110 to no more than 0.9 times the area of ​​the sealing welding layer 110, when the battery short-circuit or internal failure of the battery occurs and a large amount of gas is formed inside the battery, the gas in the battery can break through the connection between the insulating sealing layer 120 and the sealing welding layer 110, thereby releasing the gas, avoiding battery explosion, and improving battery safety.

[0085] Similarly, by setting the connection area between the insulating sealing layer 120 and the waterproof conductive layer 130 to at least 0.25 times the surface area of ​​the waterproof conductive layer 130, the connection area between the insulating sealing layer 120 and the waterproof conductive layer 130 can be made sufficiently large, ensuring that the connection strength between the two is sufficient to support the connection strength required during subsequent processes (such as the process of injecting electrolyte into the battery, which requires a pressure differential between the inside and outside of the battery to allow the electrolyte to enter the receiving cavity under the action of the pressure differential) and operation. At the same time, by setting the stacking area of ​​the insulating sealing layer 120 and the waterproof conductive layer 130 to no more than 0.95 times the area of ​​the waterproof conductive layer 130, when a battery short circuit or internal battery failure occurs, resulting in a large amount of gas formed inside the battery, the gas within the battery can break through the connection between the insulating sealing layer 120 and the waterproof conductive layer 130, allowing the gas to be released, thus preventing battery explosion and improving battery safety.

[0086] The bottom shell 200 includes a circular or elliptical bottom and an annular sidewall 220 extending toward the sealing complex 100. The end of the annular sidewall 220, near the sealing complex 100, has a transverse platform 230 extending toward the outside of the internal receiving cavity 210. The platform width L of the transverse platform 230 is greater than or equal to 2.1 times the thickness D of the annular sidewall 220. In some embodiments, the platform width L of the transverse platform 230 is less than or equal to 4.2 times the thickness D of the annular sidewall 220. The sealing welding layer 110 overlaps the transverse platform 230. During laser welding of the sealing welding layer 110 to the longitudinal welding platform, the laser fuses the edges of the longitudinal welding platform and the sealing welding layer 110. At this time, the laser is shielded by the sealing welding layer 110 and the transverse platform 230, preventing the laser from leaking into the battery interior and damaging the battery cells 300, thereby effectively protecting the battery cells 300 and improving battery safety and product yield. At the same time, during the actual melting process, the part of the horizontal platform 230 close to the longitudinal welding platform (the melting position occurs on the side of the horizontal platform 230 facing the sealing welding layer 110) will also melt with the sealing welding layer 110. In this way, the horizontal platform 230 can carry and solidify the dust formed during the welding process, preventing the dust from falling into the interior of the battery, thereby avoiding the dust affecting the short circuit of the battery, etc., which is beneficial to improving the safety of the battery and the product yield.

[0087] At the same time, by ensuring that the height H of the longitudinal weld pad is greater than or equal to 0.2 times the thickness d of the sealing weld layer 110 and less than or equal to 1.2 times the thickness d of the sealing weld layer 110, the weld strength between the sealing sealing layer and the longitudinal weld pad (in some embodiments, also including the portion of the transverse platform 230 adjacent to the longitudinal weld pad) is greater than the connection strength between the insulating sealing layer 120 and the sealing weld layer 110, and greater than the connection strength between the insulating sealing layer 120 and the waterproof conductive layer 130, but less than the load-bearing strength of the bottom housing 200 itself. This ensures that if a large amount of gas is generated within a short period of time due to a battery fault, the insulating sealing layer 120 can be first breached, and then the weld between the sealing weld layer 110 and the longitudinal weld (in some embodiments, also including the portion of the transverse platform 230 adjacent to the longitudinal weld pad) can be slowly torn, allowing for slow gas release. This prevents battery explosion and improves battery safety.

[0088] The circuit board assembly 500 can take many forms, including a single circuit board or two circuit boards. The circuit board assembly 500 includes an input board surface 550 and an output board surface 560 disposed opposite each other. The input positive electrode 510 and the input negative electrode 520 on the input board surface 550 can take many forms, such as electrode sheets or metal films formed by electroplating or chemical plating. Similarly, the output positive electrode 530 and the output negative electrode 540 on the output board surface 560 can take many forms, such as electrode sheets or metal films formed by electroplating or chemical plating.

[0089] The first connection circuit and the second connection circuit can take many forms, including conductive wires, electroplated layers, chemically plated layers, metal films, metal sheets, and the like. The first connection circuit electrically connects the input positive electrode 510 and the output positive electrode 530, allowing the output positive electrode 530 to be electrically connected to the positive electrode of the battery cell via the first connection circuit, the input positive electrode 510, the vertical conductive adhesive layer, and the waterproof conductive layer 130. The second connection circuit electrically connects the input negative electrode 520 and the output negative electrode 540, allowing the output negative electrode 540 to be electrically connected to the negative electrode of the battery cell via the second connection circuit, the input negative electrode 520, the sealing welding layer 110, and the vertical conductive adhesive layer.

[0090] The vertical conductive adhesive layer 700 includes an insulating adhesive layer and conductive particles disposed within the insulating adhesive layer, and the conductive particles are distributed within the conductive adhesive layer. There may be only one conductive particle along the thickness direction of the conductive adhesive layer, or there may be multiple conductive particles arranged at intervals. In its natural initial state, the two opposite sides of the vertical conductive adhesive layer 700 are insulated and non-conductive; when the vertical conductive adhesive layer 700 is squeezed, the conductive particles in the same column contact each other, thereby conducting the two sides of the vertical conductive adhesive layer 700. In this embodiment, after squeezing the vertical conductive adhesive layer 700, the input positive electrode 510 and the waterproof conductive layer 130 can be electrically connected, and the input negative electrode 520 and the sealing welding layer 110 can be electrically connected.

[0091] The first mating structure of the circuit board assembly can take many forms, including the edge of the circuit board or structures provided on the circuit board (such as clips, fastening holes, adhesive, etc.). Similarly, the second mating structure of the bottom housing 200 can take many forms, including the bottom of the bottom housing 200 or other structures provided on the sidewalls or bottom of the bottom housing 200 (such as clips, fastening holes, adhesive, etc.). The first and second mating structures respectively mate with the housing 610 of the electronic product 600 to generate a compressive force between the circuit board assembly and the sealing composite.

[0092] The housing 610 can include a variety of structures that cooperate with the first mating structure, such as support bosses 615, support steps 616, fastening bosses, and snaps. Similarly, the housing 610 can include a variety of structures that cooperate with the second mating structure, such as support bosses 615, support steps 616, fastening bosses, and snaps. The structure that cooperates with the first mating structure in the housing 610 is in a first position, and the structure that cooperates with the second mating structure is in a second position. The distance between the first and second positions is less than the thickness of the secondary lithium battery. Of course, in some embodiments, it is also possible to generate a compressive force between the circuit board assembly and the sealing composite by adding elastic pads or other methods.

[0093] In this embodiment, by providing a first matching structure on the circuit board assembly 500 and a second matching structure on the bottom shell, after the secondary lithium battery is installed in the shell, an extrusion force can be generated between the circuit board assembly and the sealing complex 100, so that the vertical conductive adhesive layer provided therein is squeezed, so that the input positive electrode 510 and the waterproof conductive layer 130 are connected by the vertical conductive adhesive layer, and the input negative electrode 520 and the sealing welding layer 110 are connected by the vertical conductive adhesive layer 700; that is, the positive electrode of the battery cell is connected to the output positive electrode 530 through the waterproof conductive layer 130, the vertical conductive adhesive layer 700, the input positive electrode 510, and the first connecting circuit, and the negative electrode of the battery cell is connected to the output negative electrode 540 through the sealing welding layer 110, the vertical conductive adhesive layer 700, the input negative electrode 520, and the second connecting circuit; the positive and negative electrodes of the battery cell are extended to the output board surface 560 of the circuit board assembly 500;

[0094] In this way, when the secondary lithium battery is connected to the circuit of an electronic product, the wires can be directly welded to the output positive electrode 530 and the output negative electrode 540 of the output board 560, avoiding the direct welding of the wires to the sealing complex 100, greatly reducing the difficulty of welding, improving the reliability of welding, and avoiding damage to the sealing complex 100 caused by direct welding, thereby greatly improving the safety of the battery; at the same time, the sealing complex 100 can be separated from the vertical conductive adhesive layer 700, that is, the secondary lithium battery can be disassembled into a part consisting of the circuit board assembly 500 and the vertical conductive adhesive layer 700, and another part consisting of the bottom shell 200, the sealing complex 100 and the battery cell. No matter which part fails, the other part can be completely separated and can be reused, which is conducive to improving the utilization rate of materials.

[0095] In some embodiments, the horizontal platform 230 is provided so that the welding laser is shielded by the sealing welding layer 110 and the horizontal platform 230, thereby preventing the laser from leaking into the interior of the battery and causing damage to the battery cell 300, thereby effectively protecting the battery cell 300 and improving the safety and product yield of the battery. At the same time, the horizontal platform 230 can carry and solidify the dust generated during the welding process, preventing the dust from falling into the interior of the battery, thereby preventing the dust from affecting the battery short circuit and other phenomena, which is conducive to improving the safety and product yield of the battery.

[0096] Furthermore, by setting the connection area between the insulating sealing layer 120 and the sealing welding layer 110 to be 0.2 to 0.9 times the side area of ​​the sealing welding layer 110; setting the connection area between the insulating sealing layer 120 and the waterproof conductive layer 130 to be 0.25 to 0.95 times the surface area of ​​the waterproof conductive layer 130; and setting the height of the longitudinal welding platform to be 0.2 to 1.2 times the thickness of the sealing welding layer 110, the connection area between the insulating sealing layer 120 and the sealing welding layer 110, and the connection area between the insulating sealing layer 120 and the waterproof conductive layer 130 are both large enough, and the connection strength is sufficient to support the connection strength required in subsequent processes (such as the process of injecting electrolyte into the battery, which requires a pressure difference between the inside and outside of the battery, and the electrolyte enters the receiving cavity under the action of the pressure difference) and the working process; at the same time, when a large amount of gas is generated inside the battery, the gas in the battery can break through the connection between the insulating sealing layer 120 and the sealing welding layer 110, thereby releasing the gas and preventing the battery from exploding;

[0097] Furthermore, the weld strength between the sealing layer and the longitudinal weld pad (in some embodiments, also including the portion of the transverse platform 230 adjacent to the longitudinal weld pad) is greater than the connection strength between the insulating sealing layer 120 and the sealing welding layer 110, greater than the connection strength between the insulating sealing layer 120 and the waterproof conductive layer 130, and less than the load-bearing strength of the bottom housing 200 itself. In this way, when a large amount of gas is generated within a short period of time due to a fault inside the battery, the insulating sealing layer 120 can be first broken open, and then the weld between the sealing welding layer 110 and the longitudinal weld (in some embodiments, also including the portion of the transverse platform 230 adjacent to the longitudinal weld pad) can be slowly torn apart, allowing the gas to be slowly released. This creates a dual-deflation safety measure. Whether the gas pressure inside the battery increases slowly or rapidly within a short period of time, battery explosion can be prevented by degassing and pressure relief, significantly improving battery safety.

[0098] The thickness of the vertical adhesive layer is 0.1mm to 0.3mm, with 0.13mm, 0.15mm, 0.17mm, 0.2mm, and 0.25mm being examples. The thickness of the vertical adhesive layer should be neither too thick nor too thin. If it is too thick, the squeezing force required to flatten it will be too high, which is not conducive to its use. If it is too thin, it will easily be pressed through, causing direct contact between the input plate surface 550 and the sealing composite 100, resulting in a short circuit.

[0099] The thickness of the circuit board assembly 500 ranges from 12.5 microns to 6.4 mm. The circuit board assembly 500 may include one or two circuit boards, which may be printed circuit boards or flexible circuit boards. When there are two circuit boards, they may be a combination of a printed circuit board and a flexible circuit board. The circuit board assembly 500 should not be too thick; if it exceeds 6.4 mm, it will be inconvenient for installation and use of the secondary lithium battery. It should also not be too thin, as this will result in insufficient strength and easy damage during compression.

[0100] In some embodiments, to improve the stability and reliability of battery operation, the circuit board assembly 500 includes a voltage stabilizing circuit, which is connected in series with the first connection circuit and / or the second connection circuit. The voltage stabilizing circuit can be connected in series with the first connection circuit, and the second connection circuit can also be connected in series with the voltage stabilizing circuit. Of course, in some embodiments, the voltage stabilizing circuit can be provided on both the first connection circuit and the second connection circuit. When the secondary lithium battery is operating, current passes through the voltage stabilizing circuit, ensuring a stable operating voltage for the battery.

[0101] In some embodiments, to improve battery safety, the circuit board assembly 500 includes an overload protection circuit, which is connected in series with the first connection circuit and / or the second connection circuit. The overload protection circuit can be connected in series with the first connection circuit, and the overload protection circuit can also be connected in series with the second connection circuit. Of course, in some embodiments, overload protection circuits can be provided on both the first connection circuit and the second connection circuit. When the secondary lithium battery is operating, current passes through the overload protection circuit, ensuring the safe operation of the battery.

[0102] The circuit board assembly may include a single circuit board or two circuit boards, etc., which will be described below with examples.

[0103] When the circuit board assembly 500 comprises a single circuit board, it includes a first substrate 590, with the input panel 550 and the output panel 560 located on opposite sides of the first substrate 590. In this embodiment, the first substrate 590 can be a printed circuit board (PCB) or a flexible circuit board (FPC), with the vertical conductive adhesive layer 700 located between the first substrate's central portion and the sealing composite. When the circuit board assembly 500 comprises two circuit boards, it includes a first circuit board 580 and a second circuit board 570 stacked together, with the second circuit board 570 located on the side of the first circuit board 580 facing away from the vertical conductive adhesive layer. In this embodiment, the first circuit board 580 and the second circuit board 570 can be printed circuit boards (PCBs) or flexible circuit boards, with the second circuit board 570 being a printed circuit board and the first circuit board 580 being a FPC as an example. The first circuit board 580 and the second circuit board 570 are electrically connected, and functional circuits can be provided on each of the first and second circuit boards 580, 570, or they can be electrically connected to form a functional circuit. The second circuit board 570 , the first circuit board 580 , the vertical conductive adhesive layer 700 and the sealing composite 100 are arranged in sequence.

[0104] In some embodiments, in order to improve the convenience of connecting the circuit board assembly to the electronic product 600. The electronic product 600 includes a functional circuit board 630, and the output board surface is arranged to face the functional circuit board 630. In this embodiment, the circuit board assembly is adjacent to the functional circuit board 630 of the electronic sweat-absorbing row, and the output board surface is arranged to face the functional circuit board 630. Since the output board surface faces the functional circuit board 630, the output positive electrode 530 and the output negative electrode 540 on the output board surface face the functional circuit board 630, so that the output positive electrode 530 and the output negative electrode 540 can be connected to the functional circuit board 630 through a very short line, reducing many inconveniences caused by complex lines. In this way, the convenience of connecting the secondary lithium battery to the electronic product 600 and the stability after connection are greatly reduced.

[0105] Specifically, taking an example to illustrate, the shell 610 includes a front shell 611 and a rear shell 612, and the functional circuit board 630 is installed in the front shell 611; the first matching structure includes a supporting edge, which is the edge of the output board surface, and a supporting step 616 extending circumferentially along the front shell 611 is provided in the front shell 611 corresponding to the output board surface, and the supporting step 616 is configured to support the supporting edge of the output board surface; and / or, the second matching structure includes a supporting bottom, and a supporting boss 615 is provided in the rear shell 612 corresponding to the supporting bottom, and the supporting boss 615 is located in the middle of the rear shell 612; the supporting boss 615 is configured to support the supporting bottom.

[0106] The support step 616 is arranged in an annular shape and extends along the inner side wall of the front shell 611. The functional circuit board 630 of the electronic product 600 is arranged below the support step 616, and the secondary lithium battery is arranged above the support step 616. Under the pressure of the support step 616 and the rear shell 612, the secondary lithium battery conducts the circuit board assembly and the sealing complex 100 vertically through the conductive adhesive layer. At the same time, the provision of the support step 616 ensures that the secondary lithium battery is stably supported during operation, preventing the battery from being squeezed onto the functional circuit board 630. The support boss 615 on the rear shell 612 can be parallel to the bottom of the rear shell 612, or it can protrude from the bottom of the rear shell 612 to ensure that the support boss 615 can abut against the bottom shell 200, ensuring that a forward supporting force can be applied to the secondary lithium battery.

[0107] In some embodiments, to improve the installation stability of the functional circuit board 630, a mounting step is further provided within the front housing 611. The mounting step is annularly arranged below the support step 616, and the radial dimension of the mounting step is smaller than the radial dimension of the support step 616. During installation, the functional circuit board 630 is first mounted on the mounting step, the functional circuit board 630 is secured, and then the battery is installed within the housing 610, so that the circuit board assembly overlaps the support step 616.

[0108] In other embodiments, the secondary lithium battery can also be installed in other ways, which are illustrated below. Specifically, the housing 610 includes a front housing 611 and a rear housing 612, and the functional circuit board 630 is installed in the rear housing 612;

[0109] The second mating structure includes a supporting bottom, and a supporting step 616 extending circumferentially along the front shell 611 is provided in the front shell 611 corresponding to the supporting bottom, and the supporting step 616 is configured to support the bottom of the bottom shell 200; and / or, the first mating mechanism includes a supporting edge, and a supporting boss 615 is provided in the rear shell 612 corresponding to the panel assembly, and the supporting boss 615 is located at the bottom of the rear shell 612; the supporting boss 615 is configured to support the output plate surface.

[0110] In this embodiment, compared to the previous embodiment, the secondary lithium battery is flipped 180 degrees, so that the output board surface of the circuit board assembly faces the rear shell 612, and the bottom of the bottom shell 200 faces the front side of the outer shell 610. In this case, the functional circuit board 630 can be installed on the front shell 611 or the rear shell 612. When it is installed on the front shell 611, the functional circuit board 630 is connected to the output positive electrode 530 and the output negative electrode 540 via wires. When the functional circuit board 630 is installed on the rear shell 612, it is located behind the support boss 615. In this case, there is a certain gap between the support boss 615 and the side wall of the rear shell 612, which allows for the installation of the functional circuit board 630. The support boss 615 also prevents the circuit board assembly from squeezing the functional circuit board 630. The output board surface of the circuit board assembly faces the functional circuit board 630, and the output positive electrode 530 and the output negative electrode 540 of the output board surface are very close to the functional circuit board 630. The connection between the secondary lithium battery and the functional circuit board 630 can simplify the connection line as much as possible, which is beneficial to improving the working stability of the entire electronic product 600.

[0111] In some embodiments, in order to further improve the reliability and stability of the secondary lithium battery when being squeezed, the secondary lithium battery further includes an insulating buffer pad 650, which is arranged on the support boss 615. The insulating buffer pad 650 can be an elastic buffer pad, such as an elastic plastic pad, a rubber pad, etc. Through the provision of the insulating buffer pad 650, whether it is provided with the corresponding support bottom of the bottom shell 200 or the output board surface of the circuit board assembly, the convenience of installation of the secondary lithium battery can be improved (the secondary lithium battery will not be unable to be installed due to processing errors or assembly errors. By providing the insulating buffer pad 650, a larger installation space can be reserved for the secondary lithium battery) and the reliability after installation (through the provision of the insulating buffer pad 650, the insulating buffer pad 650 is squeezed after installation, thereby ensuring the squeezing force after the battery is installed).

[0112] The present invention also provides an electronic product 600, which includes a device body and a secondary lithium battery, wherein the battery is electrically connected to the device body to provide electrical energy to the device body. The specific structure of the battery is referred to in the above-mentioned embodiments. Since this battery adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above-mentioned embodiments, and will not be described in detail here. The battery can be configured as a button battery, which is mainly used in electronic product 600 to provide electrical energy for electronic product 600. Among them, electronic product 600 can be headphones, watches, etc., which use electronic products 600 with lower voltages.

[0113] In some embodiments, the electronic product 600 takes headphones as an example, the device body includes headphones, the headphones include a shell 610 and a speaker 640, the shell 610 includes a front shell 611 and a rear shell 612, the speaker 640 is arranged in the front shell 611, and the secondary lithium battery is located on the side of the speaker 640 facing away from the headphone outlet 620.

[0114] The above descriptions are merely optional embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present description and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A secondary lithium battery for an electronic product having a housing, wherein the secondary lithium battery is installed in the housing, characterized in that: The secondary lithium battery comprises a bottom shell, a sealing complex and a battery cell, wherein the bottom shell and the sealing complex form an internal receiving cavity, and the battery cell is placed in the internal receiving cavity; The sealing composite body comprises a sealing welding layer, an insulating sealing layer and a waterproof conductive layer which are stacked; One of the electrodes of the battery cell is electrically connected to the waterproof conductive layer, and the other electrode is electrically connected to the sealing welding layer or the bottom shell; The bottom shell includes a circular or elliptical bottom and an annular side wall extending toward the sealing complex; The sealing welding layer and the portion of the annular side wall close to the sealing welding layer are fused together to form a seal; The sealing welding layer is provided with an avoidance hole to expose part of the waterproof conductive layer; The secondary lithium battery further comprises: A circuit board assembly having an input board surface and an output board surface disposed opposite to each other, the input board surface having an input positive electrode and an input negative electrode, and the output board surface having an output positive electrode and an output negative electrode; the circuit board assembly having a first connecting circuit and a second connecting circuit, the first connecting circuit connecting the input positive electrode and the output positive electrode, and the second connecting circuit connecting the input negative electrode and the output negative electrode; A vertical conductive adhesive layer is provided between the input plate surface and the side of the sealing composite body facing away from the internal receiving cavity, so as to connect the input positive electrode and the waterproof conductive layer, and connect the input negative electrode and the sealing welding layer; The circuit board assembly has a first mating structure, and the bottom housing has a second mating structure. The first mating structure and the second mating structure are configured to mate with the housing of the electronic product so that the sealing composite and the input board surface squeeze the vertical conductive adhesive layer, so that the vertical conductive adhesive layer conducts between the input positive electrode and the waterproof conductive layer, and conducts between the input negative electrode and the sealing welding layer. The electronic product includes a functional circuit board, and the output board is arranged facing the functional circuit board; The housing comprises a front housing and a rear housing; The first matching structure includes a supporting edge. A supporting boss is provided in the rear shell corresponding to the output plate surface. The supporting boss is located at the bottom of the rear shell. The supporting boss is configured to support the output plate surface.

2. The secondary lithium battery according to claim 1, wherein The housing comprises a front shell and a rear shell, and the functional circuit board is installed in the front shell; The first matching structure includes a supporting edge, which is an edge of the output plate surface. A supporting step extending along the circumference of the front shell is provided in the front shell corresponding to the output plate surface, and the supporting step is configured to support the supporting edge of the output plate surface; and / or, The second matching structure includes a supporting bottom, and a supporting boss is provided in the rear shell corresponding to the supporting bottom. The supporting boss is located in the middle of the rear shell; the supporting boss is configured to support the supporting bottom.

3. The secondary lithium battery according to claim 1, wherein The second matching structure includes a supporting bottom. A supporting step extending along the circumference of the front shell is provided in the front shell corresponding to the supporting bottom. The supporting step is configured to support the bottom of the bottom shell.

4. The secondary lithium battery according to claim 2 or 3, wherein: The secondary lithium battery further includes an insulating buffer pad, which is arranged on the supporting boss.

5. The secondary lithium battery according to claim 1, wherein The thickness of the vertical conductive adhesive layer is 0.1 mm to 0.3 mm; and / or, The thickness of the circuit board assembly is 12.5 microns to 6.4 mm.

6. The secondary lithium battery according to claim 1, wherein The circuit board assembly has a voltage stabilizing circuit, and the voltage stabilizing circuit is connected in series to the first connecting circuit and / or the second connecting circuit.

7. The secondary lithium battery according to claim 1, wherein The circuit board assembly has an overload protection circuit, and the overload protection circuit is connected in series with the first connection circuit and / or the second connection circuit.

8. An electronic product, characterized in that: The device comprises a device body and a secondary lithium battery as claimed in any one of claims 1 to 7, wherein the battery is electrically connected to the device body to provide electrical energy to the device body.

9. The electronic product according to claim 8, wherein: The device body includes an earphone, which includes a shell and a speaker. The shell includes a front shell and a rear shell. The speaker is arranged in the front shell, and the secondary lithium battery is located on the side of the speaker facing away from the earphone sound outlet.

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