WO2022227651A1 - Battery case and battery - Google Patents

Abstract

Disclosed in the present invention are a battery case and a battery. A battery case is divided into a bottom case and a sealing lid, and the sealing lid is divided into an outer contact layer, an insulating layer and an inner contact layer, wherein an electrode contact portion of the outer contact layer passes through the insulating layer and the inner contact layer, so as to be electrically conductive with one electrode of a cell, and the other electrode of the cell is electrically conductive with the bottom case; and after the inner contact layer is welded to the bottom case, the cell can be encapsulated. The inner contact layer is insulated from the outer contact layer by means of the insulating layer, and therefore the bottom case is also insulated from the outer contact layer, such that a short circuit caused by the two electrodes of the cell being conductive with each other can be prevented. The inner contact layer of the sealing lid is pre-insulated from the outer contact layer thereof, and therefore when the bottom case is encapsulated by means of the sealing lid, it is only necessary to weld the inner contact layer to the bottom case, and no additional insulating film needs to be provided, thereby simplifying an encapsulation process of a battery and improving the encapsulation efficiency thereof.

Description

Battery Cases and Batteries technical field

The present invention relates to the technical field of batteries, in particular to a battery case and a battery.

Background technique

In the existing button battery, the battery case is formed by splicing a positive electrode case and a negative electrode case, and insulation between the positive electrode case and the negative electrode case is required to avoid short circuit of the button battery; An insulating film is provided to achieve insulation, and the positive electrode case and the negative electrode case are welded and fixed. During the processing, it is difficult to set the insulating film, which makes the processing of the button battery more difficult and reduces the processing efficiency.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to provide a battery case for a button battery, aiming at solving the technical problem of how to improve the processing efficiency of the battery.

To achieve the above object, the battery case proposed by the present invention includes a cup-shaped bottom case and a cover for sealing the opening of the bottom case;

The bottom shell includes a circular or oval bottom wall and an annular side wall;

The cover includes an outer contact layer, an insulating layer and an inner contact layer in sequence from the outer guide to the inner;

The maximum outer diameter D1 of the outer contact layer is smaller than the maximum outer diameter D2 of the inner contact layer;

The outer contact layer includes an electrode contact portion and a conductive adhesive portion;

The insulating layer includes an insulating bonding portion, an insulating protection portion and an insulating opening portion;

The inner contact layer includes a welding part, a welding bonding part and a welding opening part;

The side wall is provided with a welding support part near the opening;

The electrode contact portion is recessed toward the inside of the battery case through the insulating opening portion and the welding opening portion, and is used for electrical connection with one of the electrodes of the cell, so that the outer contact layer is connected to the cell. To form electrical conduction, the diameter D3 of the electrode contact portion is less than or equal to half of the maximum outer diameter D2 of the inner contact layer;

The insulating protection part fills the gap between the electrode welding part, the insulating opening part and the welding opening part, so as to enhance the protection of the insulating bonding part;

The conductive bonding part is used for seamless bonding with the insulating bonding part to enhance the strength of the cover and prevent external water from penetrating into the interior of the battery case;

the welding part is used for welding connection with the welding support part, so that the cover and the bottom case are sealed;

The welding bonding part is used for seamless bonding with the insulating bonding part, strengthening the strength of the cover, reducing the direct contact area between the insulating bonding part and the inside of the battery case, and preventing the penetration of external water into the battery case. inside the battery case;

Before the cover is sealed with the bottom case, after the insulating adhesive part is melted by an insulating anti-corrosion material with a thermal shrinkage rate of 6% or less at 100° C. or more, the insulating adhesive part is melted with the conductive adhesive part. , The welding bonding part is seamlessly bonded, and the bonding strength between the conductive bonding part and the welding bonding part is greater than or equal to 1.0N per square millimeter under cooling and normal temperature. The thickness d4 of the connecting portion is 0.01mm-2.5mm, and the contact area S0 between the insulating adhesive portion and the battery case interior satisfies π*D3*D3*1/4<=S0<=π*D2*D2*1/ 8.

Optionally, the material of the outer contact layer is stainless steel, the thickness d5 of the outer contact layer is 0.1 mm-0.25 mm; and/or the material of the inner contact layer is stainless steel, and the thickness of the inner contact layer is d6 is 0.1mm-0.25mm.

Optionally, the material of the insulating layer is one or more of PP, PFA, PVDF, PTFE, ETFE and PVC.

Optionally, the bonding strength between the insulating bonding part and the conductive bonding part and the welding bonding part under normal cooling temperature is less than or equal to 5.0 N/mm2.

Optionally, the area S1 of the insulating adhesive part and the area S2 of the insulating layer satisfy S1/S2>=0.6; and/or, the area S1 of the insulating adhesive part and the area of the outer contact layer S3 satisfies S1/S3>=0.5.

Optionally, a first bonding enhancement layer is provided on the first surface layer of the conductive bonding portion close to the insulating bonding portion, for enhancing the bonding strength with the insulating bonding portion; and/or A second bonding enhancement layer is arranged on the second surface layer of the welding bonding part close to the insulating bonding part, which is used to strengthen the bonding strength with the insulating bonding part.

Optionally, the side wall is further provided with an extension part, the extension part protrudes from the welding support part and extends outward by a certain height h, and the extension height h satisfies the thickness d4 of the insulating bonding part or more. and the sum of the thickness d5 of the outer contact layer.

Optionally, the battery case further includes a protection member, the protection member is provided on the extension portion, the welding portion, the insulating adhesive portion and the bottom case after the cover is sealed with the bottom case. The gap filling liquid glue between the outer edges of the outer contact layer is formed by curing at normal temperature.

Optionally, the insulating protection part is provided with a reinforcing unit, and the reinforcing unit extends toward the center and the edge of the battery case respectively, and is used for enhancing the fastness of the insulating layer and the inner contact layer.

The present invention also provides a battery, comprising a battery cell and the above-mentioned battery case, wherein one pole of the battery cell is electrically connected with the outer contact layer of the battery case, and the other pole is in contact with the inner contact layer of the battery case The layers and/or the bottom case are electrically connected.

In the present invention, the battery case is divided into a bottom case and a cover, and the cover is divided into an outer contact layer, an insulating layer and an inner contact layer, wherein the electrode contact portion of the outer contact layer passes through the insulating layer and the inner contact layer to communicate with the electrical One pole of the core is electrically connected, and the other pole of the battery core is electrically connected to the bottom case. After the inner contact layer and the bottom case are welded, the encapsulation of the battery core can be realized. Since the inner contact layer and the outer contact layer are insulated by the insulating layer, Therefore, the bottom case is also insulated from the outer contact layer, thereby preventing the two electrodes of the cell from conducting short-circuits with each other. It is only necessary to weld the inner contact layer and the bottom case, and there is no need to install an insulating film, which can simplify the packaging process of the battery and improve the packaging efficiency; in addition, the contact area S0 between the insulating bonding part and the interior of the battery case is limited to π* D3*D3*1/4<=S0<=π*D2*D2*1/8, which can reduce the area of the insulating bonding part exposed to the electrolyte, thereby reducing the corrosion of the electrolyte to the insulating layer to ensure the insulating layer Adhesion stability of the outer and inner contact layers.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained according to the structures shown in these drawings without creative efforts.

1 is a structural exploded view of an embodiment of a battery case of the present invention;

2 is a cross-sectional exploded view of an embodiment of a battery case of the present invention;

3 is a schematic cross-sectional view of an embodiment of a battery case of the present invention;

4 is a schematic cross-sectional view of an embodiment of a cover according to the present invention;

FIG. 5 is a structural exploded view of another embodiment of the battery case of the present invention.

Description of reference numbers:

label	name	label	name	label		name
10	bottom case	20	cover	11	bottom wall
12	side wall	twenty one	outer contact layer	twenty two	Insulation
twenty three	inner contact layer	211	electrode contact	212	conductive adhesive
221	Insulation bonding part	222	Insulation protection department	223	Insulation opening
231	Welding Department	232	Welding and bonding part	233	Welding hole
121	Welding support	213	First Adhesion Enhancement Layer	234	Second Adhesion Enhancement Layer
122	extension	30	protector	224	Enhancement unit
225	first adhesive layer	226	Anti-conduction layer	227	second adhesive layer

The realization, functional characteristics and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that if there are directional indications (such as up, down, left, right, front, back, etc.) involved in the embodiments of the present invention, the directional indications are only used to explain a certain posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly.

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 used for the purpose of description, and should not be construed as indicating or implying Its relative importance or implicitly indicates the number of technical features indicated. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In addition, the meaning of "and/or" appearing in the whole text includes three parallel schemes, and taking "A and/or B as an example", it includes scheme A, scheme B, or scheme that A and B satisfy at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of such technical solutions does not exist. , is not within the scope of protection required by the present invention.

The present invention provides a battery case for a button battery.

In the embodiment of the present invention, as shown in FIGS. 1 to 5 , the battery case includes a cup-shaped bottom case 10 and a cover 20 for sealing the opening of the bottom case 10 ; the bottom case 10 includes a circular Or an elliptical bottom wall 11 and an annular side wall 12; the cover 20 includes an outer contact layer 21, an insulating layer 22 and an inner contact layer 23 in sequence from the outside to the inside; the maximum outer diameter D1 of the outer contact layer 21 It is smaller than the maximum outer diameter D2 of the inner contact layer 23; the outer contact layer 21 includes an electrode contact part 211 and a conductive bonding part 212; the insulating layer 22 includes an insulating bonding part 221, an insulating protection part 222 and an insulating opening. The inner contact layer 23 includes a welding part 231, a welding bonding part 232 and a welding opening part 233; the side wall 12 is provided with a welding support part 121 near the opening; the electrode contact part 211 passes through the The insulating opening portion 223 and the welding opening portion 233 are recessed toward the inside of the battery case, and are used for electrical connection with one of the poles of the battery cell, so that the outer contact layer 21 is electrically connected to the battery core. The diameter D3 of the electrode contact portion 211 is less than or equal to half of the maximum outer diameter D2 of the inner contact layer 23 ; the insulating protection portion 222 fills the electrode welding portion 231 and the insulating opening portion 223 and the welding opening portion 233 The gap between the two parts is used to enhance the protection of the insulating bonding part 221; the conductive bonding part 212 is used for seamless bonding with the insulating bonding part 221 to enhance the strength of the cover 20 and prevent the External water penetrates into the interior of the battery case; the welding part 231 is used for welding connection with the welding support part 121 to complete the sealing of the cover 20 and the bottom case 10; the welding and bonding part 232 is used for It is seamlessly bonded to the insulating adhesive portion 221, which strengthens the strength of the cover 20, reduces the direct contact area between the insulating adhesive portion 221 and the interior of the battery case, and prevents external water from penetrating into the interior of the battery case. ;

Before the cover 20 is sealed with the bottom case 10 , the insulating adhesive portion 221 is melted by an insulating material with a thermal shrinkage rate of 6% or less at 100° C. or less, and is connected to the conductive material. The bonding portion 212 and the welding bonding portion 232 are seamlessly bonded, and the bonding strength between the conductive bonding portion 212 and the welding bonding portion 232 is greater than or equal to 1.0N per unit under cooling and normal temperature. square millimeter, the thickness d4 of the insulating adhesive portion 221 is 0.01mm-2.5mm, and the contact area S0 between the insulating adhesive portion 221 and the interior of the battery case satisfies π*D3*D3*1/4<=S0< =π*D2*D2*1/8. For example, d4 can be 0.01mm, 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.5mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm and 2.5mm are specifically designed. For small button batteries, the preferred thickness d4 is 0.15mm-0.25mm. , the insulating adhesive portion 221 and the insulating layer 22 are integrally formed.

Compared with the prior art, the battery case of the present application is sealed by welding, which greatly improves the sealing performance and stability, instead of relying on the physical force extrusion between the cases for sealing, In addition, since the cover 20 is prepared in advance, the insulating adhesive portion 221 is used for insulation, which can improve the insulation, and at the same time, can play a protective role under certain conditions. Further, the cover 20 of the battery case of the present application adopts a three-layer structure, and the stability and reliability of the structure are enhanced. Since the insulating bonding portion 221 is located between the two layers of stainless steel, its waterproof and anti-corrosion properties of electrolyte are both It is very strong, and the contact area between the insulating adhesive part 221 and the outside of the battery case is small, which can effectively prevent external moisture from entering the battery case. The path length is relatively long, which further avoids the influence of external moisture on the cells and electrolyte inside the battery case. Similarly, for the inside of the battery case, only the inner edge of the insulating adhesive part 221 can be connected to the inside of the battery case. It can effectively reduce the contact area between the electrolyte and the insulating bonding part 221, effectively protect the insulating bonding part 221, and avoid the softening and corrosion of the electrolyte on the insulating bonding part 221. In order to improve the service life of the battery, further, the path of the insulating adhesive portion 221 from the inside of the battery case to the outside of the battery case is also longer, which can further improve the service life of the battery.

The bottom case 10 can be made of stainless steel plate, and the opening of the bottom case 10 is upward to accommodate the battery core and the electrolyte; wherein, the bottom wall 11 and the side wall 12 can be integrally injection-molded or fixed by welding, which is not done here. limit. The outer contact layer 21 and the inner contact layer 23 of the cover 20 can be connected by a stainless steel plate, wherein the outer contact layer 21 is used to connect with one of the electrodes of the cell, and the inner contact layer 23 is connected to the bottom case 10 to connect with the cell. connected to the other electrode. Since there is an insulating layer 22 between the outer contact layer 21 and the inner contact layer 23, the outer contact layer 21 and the inner contact layer 23 are insulated from each other, so that the bottom case 10 and the cover 20 can be insulated from each other to prevent the two The electrodes are connected to each other, so that the cover 20 and the bottom wall 11 of the bottom case 10 can respectively form two output electrodes of the battery, and the two output electrodes can be prevented from being connected to each other and short-circuited. Compared with the prior art, the casing of the current button battery adopts the upper and lower casings, with a plastic insulating ring in the middle. As for the side wall of the battery casing, it has a three-layer structure. It can only be one layer, and in the case of the same size case, the battery case of the present application increases the available space inside, which is beneficial to increase the capacity of the entire battery.

The welding portion 231 , that is, the position where the inner contact layer 23 is used for welding with the welding support portion 121 , and the welding portion 231 is provided on the peripheral wall of the inner contact layer 23 . The maximum outer diameter D1 of the outer contact layer 21 is smaller than the maximum outer diameter D2 of the inner contact layer 23 , that is, the welding portion 231 will protrude from the peripheral wall of the outer contact layer 21 in the radial direction, so that the peripheral wall of the outer contact layer 21 and the welding support portion A space is formed between 121 to avoid contact between the outer contact layer 21 and the sidewall 12 . The welding opening portion 233 is the position where the inner contact layer 23 is opened, and the welding bonding portion 232 is used for bonding with the insulating layer 22 . The welding portion 231 is welded with the side wall 12 , which can not only realize the mutual fixation of the cover 20 and the bottom case 10 , but also realize the electrical conduction between the inner contact layer 23 and the side wall 12 . The insulating opening portion 223 of the insulating layer 22 corresponds to the welding opening portion 233 of the inner contact layer 23, so that the electrode contact portion 211 of the outer contact layer 21 can be recessed toward the interior of the battery case through the insulating opening portion 223 and the welding opening portion 233. Assume. The insulating opening portion 223 and the welding opening portion 233 can be opened in the middle of the cover 20 , so that the electrode contact portion 211 can maintain a sufficient distance from each position of the side wall 12 .

When the electrode contact part 211 is recessed toward the inside of the battery case, it will pass through the insulating opening part 223 and the welding opening part 233 to shorten the distance with the battery cell, so that the electrode of the battery core can more easily contact the electrode contact part 211, and This makes it easier for the electrode to avoid the inner contact layer 23 . The top surface and the bottom surface of the insulating adhesive portion 221 are respectively bonded to the conductive adhesive portion 212 and the soldering adhesive portion 232 , so as to realize the insulating connection between the outer contact layer 21 and the inner contact layer 23 . The inner contact layer 23 is welded and sealed with the side wall 12 , and the outer contact layer 21 and the inner contact layer 23 are seamlessly bonded by the insulating layer 22 , so that the cover 20 can seal the bottom case 10 . Wherein, when the inner contact layer 23 and the side wall 12 are soldered, the inner contact layer 23 and the outer contact layer 21 have been insulated in advance, so there is no need to provide an additional insulating film.

The insulating bonding part 221 is made of a material with insulating properties and anti-corrosion of the electrolyte solution, and its thermal shrinkage rate is less than 6% when it is greater than or equal to 100 ° C. The thermal shrinkage rate refers to the thermoplastic material due to its inherent thermal expansion rate. That is to say, when the temperature is greater than or equal to 100°C, the volume change of the insulating adhesive part 221 does not exceed 6% of the original volume, so that the insulating adhesive part 221 can be fully melted and then the inner contact layer 23 It is fully connected with the outer contact layer 21 to ensure the bonding effect. The bonding strength between the insulating bonding portion 221 and the conductive bonding portion 212 and the welding bonding portion 232 is greater than or equal to 1.0N per square millimeter under cooling and normal temperature, which can ensure that the insulating bonding portion 221 and the inner contact layer 23 and Adhesion stability of the outer contact layer 21; specifically, the adhesive strength between the insulating adhesive portion 221 and the conductive adhesive portion 212 and the soldering adhesive portion 232 under cooling and normal temperature is less than or equal to 5.0N /square millimeter, so as to prevent the internal stress of the cover 20 from being too high, so that the cover 20 can be prevented from being damaged due to internal force during subsequent processing or use. The thickness d4 of the insulating bonding portion 221 is set to 0.01mm-2.5mm, so that the insulating bonding portion 221 can stably withstand changes in temperature or external force, so as to improve the bonding stability of the insulating bonding portion 221, and at the same time, it can be reasonably controlled The overall thickness dimension of the cover 20 .

After the electrode contact portion 211 passes through the insulating opening portion 223 and the welding opening portion 233, an annular gap will be formed between its peripheral wall and the welding opening portion 233, and the insulating protection portion 222 is annularly arranged and filled in the gap to block the gap. The edge connection between the insulating bonding portion 221 and the welding bonding portion 232 prevents the electrolyte from corroding, thereby ensuring the bonding stability of the insulating bonding portion 221 and the welding bonding portion 232 . The hole wall of the insulating opening portion 223 may extend to connect with the peripheral wall of the electrode contact portion 211 , and the protruding portion of the welding opening portion 233 will be exposed to the electrolyte, and the area of the protruding portion is also the insulating bonding portion. 221 Contact area with the inside of the battery case.

The contact area S0 between the insulating adhesive portion 221 and the battery case satisfies π*D3*D3*1/4<=S0<=π*D2*D2*1/8; wherein, π*D3*D3*1 /4 is the area of the electrode contact portion 211, and π*D2*D2*1/8 is half of the area of the inner contact layer 23; thus, the area of the insulating adhesive portion 221 exposed to the electrolyte can be reduced to reduce the amount of electrolysis The corrosion damage of the insulating adhesive part 221 by the liquid can ensure the adhesive area between the insulating adhesive part 221 and the conductive adhesive part 212 to ensure the bonding strength, and at the same time, it can also ensure the area of the electrode contact part 211, so that the electrical The electrode of the core and the electrode contact portion 211 have a sufficient welding area.

In the present invention, the battery case is divided into a bottom case 10 and a cover 20, and the cover 20 is divided into an outer contact layer 21, an insulating layer 22 and an inner contact layer 23, wherein the electrode contact portion 211 of the outer contact layer 21 passes through The insulating layer 22 and the inner contact layer 23 are electrically connected to one pole of the cell, and the other pole of the cell is electrically connected to the bottom case 10 , and the inner contact layer 23 and the bottom case 10 can be welded to realize the packaging of the cell , since the inner contact layer 23 and the outer contact layer 21 are insulated by the insulating layer 22, the bottom case 10 will also be insulated from the outer contact layer 21, thereby preventing the two electrodes of the cell from conducting short-circuits with each other; The contact layer 23 and the outer contact layer 21 have been pre-insulated, so when the cover 20 is encapsulated in the bottom case 10, only the inner contact layer 23 and the bottom case 10 need to be welded, and there is no need to provide an insulating film, which can simplify the battery The packaging process improves the packaging efficiency; in addition, the contact area S0 between the insulating adhesive part 221 and the interior of the battery case is limited to π*D3*D3*1/4<=S0<=π*D2*D2*1/8, which can be The area of the insulating adhesive portion 221 exposed to the electrolyte is reduced, thereby reducing the corrosion of the insulating layer 22 by the electrolyte, so as to ensure the bonding stability of the outer contact layer 21 and the inner contact layer 23 of the insulating layer 22 .

Specifically, the material of the outer contact layer 21 is stainless steel, and the thickness d5 of the outer contact layer 21 is 0.1 mm-0.25 mm; and/or, the material of the inner contact layer 23 is stainless steel, and the inner contact layer The thickness d6 of 23 is 0.1mm-0.25mm. For example, d5 and d6 can be 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.5mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, 2.5mm mm specific design. Stainless steel can be 304 stainless steel, which contains high nickel and austenite single-phase structure at room temperature, has high corrosion resistance, good cold work forming and weldability, and has low temperature, room temperature and high temperature. High plasticity and toughness. Setting the outer contact layer 21 and the inner contact layer 23 to be SUS304 can ensure the structural stability of the cover 20 during processing and the chemical stability when used as a battery case.

The thickness d5 of the outer contact layer 21 and the thickness d6 of the inner contact layer 23 are set to 0.1mm-0.25mm, which can not only make the outer contact layer 21 and the inner contact layer 23 have sufficient structural strength, but also can reasonably control the thickness of the cover 20. Overall thickness dimension. In practical applications, the insulating layer 22 is made of PP (polypropylene), PFA (copolymer of a small amount of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene), PVDF (polyvinylidene fluoride), PTFE One or more of (polytetrafluoroethylene), ETFE (ethylene-tetrafluoroethylene copolymer), PVC (polyvinyl chloride).

In one embodiment, the area S1 of the insulating adhesive portion 221 and the area S2 of the insulating layer 22 satisfy S1/S2>=0.6; and/or, the area S1 of the insulating adhesive portion 221 is the same as the area S2 of the insulating layer 22. The area S3 of the outer contact layer 21 satisfies S1/S3>=0.5, thus, the bonding area between the insulating layer 22 and the outer contact layer 21 can be effectively guaranteed, and the connection stability between the insulating layer 22 and the outer contact layer 21 can be improved; The size of the insulating opening portion 223 can be reasonably controlled, so as to effectively control the area of the electrode contact portion 211 and improve the area utilization rate of the outer contact layer 21 .

In one embodiment, as shown in FIG. 3 , the first surface layer of the conductive adhesive portion 212 close to the insulating adhesive portion 221 is provided with a first adhesive enhancement layer 213 for strengthening the adhesive bonding with the insulating adhesive portion 221 . and/or, a second bonding enhancement layer 234 is provided on the second surface layer of the welding bonding portion 232 close to the insulating bonding portion 221 for strengthening the bonding strength with the insulating bonding portion 221. Adhesion strength between the joints 221 . The specific form of the first bonding enhancement layer 213 is not limited, as long as the connection area with the insulating bonding portion 221 can be increased to strengthen the bonding strength. For example, the first adhesion-enhancing layer 213 may be configured as a protrusion. For the specific form and function of the second adhesion enhancement layer 234 , please refer to the first adhesion enhancement layer 213 . It should be noted that the first adhesion enhancement layer 213 and the second adhesion enhancement layer 234 can be indirectly matched through the insulating layer 22 , so as to further improve the bonding stability of the outer contact layer 21 , the insulating layer 22 and the inner contact layer 23 .

Specifically, as shown in FIG. 4 , the first adhesion enhancement layer 213 is the first surface layer of the first stainless steel layer close to the insulating adhesive portion 221 that is processed by sandblasting to form a uniform first rough surface and/or the second adhesion enhancement layer 234 is the second surface layer of the second stainless steel layer close to the insulating adhesive portion 221 by sandblasting to form a uniform second rough surface layer. It can be understood that the uniformity in this embodiment does not mean absolute uniformity, but a natural uniform rough surface formed after the first surface layer is sandblasted. The first rough surface layer can make the adhesion between each part of the first surface layer and the insulating adhesive part 221 more uniform, thereby avoiding stress concentration. Similarly, the second matte surface layer can also make the adhesion between each part of the second surface layer and the insulating adhesive portion 221 more uniform. Forming the first adhesion enhancement layer 213 and the second adhesion enhancement layer 234 by sandblasting can simplify the processing method of the first adhesion enhancement layer 213 and the second adhesion enhancement layer 234 to improve the processing efficiency.

In another embodiment, the first adhesion enhancement layer 213 is a first inclined sheet protruding from the first surface layer and having a certain inclination angle with the first surface layer, and the height of the first inclined sheet is less than The thickness of the insulating bonding portion 221, the second bonding enhancement layer 234 is a second inclined sheet protruding from the second surface layer and having a certain inclination angle with the second surface layer, the second inclined sheet The height of the insulating adhesive portion 221 is smaller than the thickness of the insulating adhesive portion 221 , the first inclined sheet and the second inclined sheet are in opposite directions, and are alternately arranged with each other. The number of the first inclined sheets is multiple and distributed on the first surface layer, and the melted adhesive insulating layer 22 can fill the space between two adjacent first inclined sheets to adhere to the side surfaces of the first inclined sheets . The height of the first inclined sheet is the vertical distance between the end of the first inclined sheet and the first surface layer, and the height of the first inclined sheet is smaller than the thickness of the insulating adhesive portion 221, which can prevent the first inclined sheet from passing through the insulating adhesive portion 221 and being connected with each other. The second stainless steel layer contacts. For the distribution mode and function of the second inclined sheet, reference may be made to the first inclined sheet. The first inclined sheet and the second inclined sheet are arranged alternately with each other in the longitudinal direction, so that the first inclined sheet and the second inclined sheet after the insulating adhesive part 221 are inserted can be adjacent to each other, so that the insulating adhesive can be not reduced. On the basis of the thickness of the portion 221 , the outer contact layer 21 and the inner contact layer 23 can be closer to each other, so as to improve the structural strength of the cover 20 .

In yet another embodiment, the first adhesion enhancement layer 213 is a first groove recessed in the first surface layer, and the recessed direction of the first groove is away from the direction of the insulating adhesive layer; and/or The second adhesion enhancement layer 234 is a second groove recessed in the second surface layer, and the direction of the recess of the second groove is away from the direction of the insulating adhesive layer. The number of the first grooves is multiple, the plurality of first grooves are distributed on the first surface layer, and the melted insulating adhesive portion 221 can be filled in the first grooves to increase the connection area with the first surface layer, thereby strengthening the Adhesion strength between the outer contact layer 21 and the insulating adhesive portion 221 . The arrangement and functions of the second grooves can be referred to the first grooves, which will not be repeated here.

In one embodiment, as shown in FIG. 1 to FIG. 3 , the side wall 12 is further provided with an extension portion 122 , the extension portion 122 protrudes from the welding support portion 121 and extends outward by a certain height h. The extension height h is equal to or greater than the sum of the thickness d4 of the insulating adhesive portion 221 and the thickness d5 of the outer contact layer 21 . The extension portion 122 extends upward from the top of the welding support portion 121 , and the top of the extension portion 122 protrudes from the top surface of the outer contact layer 21 , so that the extension portion 122 can be connected with the protective cover covering the outer contact layer 21 , Thereby, the cover 20 is effectively protected.

Specifically, as shown in FIGS. 1 to 3 , the battery case further includes a protection member 30 , and the protection member 30 is provided on the extension portion 122 , the protection member 30 after the cover 20 and the bottom case 10 are sealed. The gaps between the welding portion 231 , the insulating adhesive portion 221 and the outer edge of the outer contact layer 21 are filled with liquid glue which is formed by curing at room temperature. The top surface of the part of the insulating adhesive part 221 protruding from the peripheral wall of the outer contact layer 21 forms the groove bottom of the groove, and the peripheral wall of the outer contact layer 21 and the inner peripheral wall of the extension part 122 form the groove wall of the groove, so that the groove runs along the outer surface of the groove. The circumferential extension of the contact layer 21 . The protection member 30 can not only cover the top surface of the protruding part of the insulating adhesive layer, but also effectively isolate the outer contact layer 21 from the extension portion 122, thereby preventing the outer contact layer 21 from forming electrical conduction with the inner contact layer 23 or the sidewall 12. . It can be understood that, setting the protection member 30 to be formed by curing liquid glue can not only achieve the insulation between the outer contact layer 21 and the inner contact layer 23 or the extension part 122 but also reduce the effect of the protection member 30 on the outer contact layer 21 or the extension part 122 The pressure is strong to facilitate the deformation of the outer contact layer 21 or the extension portion 122, thereby ensuring the structural stability of the battery case.

In practical applications, as shown in FIG. 1 to FIG. 3 , the insulating protection part 222 is provided with reinforcing units 224 , and the reinforcing units 224 extend to the center and the edge of the battery case respectively for reinforcing the insulating layer 22 and the tightness of the inner contact layer 23. The reinforcing unit 224 extends along the circumferential direction of the insulating protection portion 222, and the reinforcing unit 224 abuts against the bottom of the electrode contact portion 211 and the bottom of the inner contact layer 23, so as to enhance the structural strength of the middle of the cover 20 and prevent the middle of the cover 20 from being squeezed Compression deformation.

In one embodiment, as shown in FIG. 5 , the insulating layer 22 may include a laminated first adhesive layer 225 , an anti-conduction layer 226 and a second adhesive layer 227 , wherein the first adhesive layer 225 contacts the outside The layer 21 is bonded to the anti-conduction layer 226, the second adhesive layer 227 bonds the inner contact layer 23 to the anti-conduction layer 226, and the anti-conduction layer 226 can ensure that the outer contact layer 21 and the inner contact layer 23 are insulated from each other . In this way, the first adhesive layer 225 and the second adhesive layer 227 only need to have adhesive properties, and the anti-conduction layer 226 only needs to have insulating properties, and the two properties of the insulating layer 22 are realized through different functional levels , the bonding performance and insulating performance of the corresponding level can be further strengthened, so as to improve the overall performance of the insulating layer 22 .

The present invention also provides a battery, which includes a battery cell and a battery case. The specific structure of the battery case refers to the above-mentioned embodiments. Since this battery adopts all the technical solutions of all the above-mentioned embodiments, it has at least the technical solutions of the above-mentioned embodiments. All the beneficial effects brought by the scheme will not be repeated here. Wherein, one pole of the battery cell is electrically connected to the outer contact layer 21 of the battery case, and the other pole is electrically connected to the inner contact layer 23 of the battery case and/or the bottom case 10 . The battery can be set as a button battery, and the button battery is mainly used in electronic products to provide electrical energy for the electronic products. Among them, the electronic products may be earphones, watches, etc., and use electronic products with lower voltages.

The above descriptions are only optional embodiments of the present invention, and are not intended to limit the scope of the present invention. Under the inventive concept of the present invention, any equivalent structural transformations made by using the contents of the description and drawings of the present invention, or direct/indirect Applications in other related technical fields are included in the scope of patent protection of the present invention.

Claims (10)

1. A battery case for a button battery, characterized in that:

   the battery case includes a cup-shaped bottom case and a cover for sealing the opening of the bottom case;

   The bottom shell includes a circular or oval bottom wall and an annular side wall;

   The cover includes an outer contact layer, an insulating layer and an inner contact layer in sequence from the outer guide to the inner;

   The maximum outer diameter D1 of the outer contact layer is smaller than the maximum outer diameter D2 of the inner contact layer;

   The outer contact layer includes an electrode contact portion and a conductive adhesive portion;

   The insulating layer includes an insulating bonding portion, an insulating protection portion and an insulating opening portion;

   The inner contact layer includes a welding part, a welding bonding part and a welding opening part;

   The side wall is provided with a welding support part near the opening;

   The electrode contact portion is recessed toward the inside of the battery case through the insulating opening portion and the welding opening portion, and is used for electrical connection with one of the electrodes of the cell, so that the outer contact layer is connected to the cell. To form electrical conduction, the diameter D3 of the electrode contact portion is less than or equal to half of the maximum outer diameter D2 of the inner contact layer;

   The insulating protection part fills the gap between the electrode welding part, the insulating opening part and the welding opening part, so as to enhance the protection of the insulating bonding part;

   The conductive bonding part is used for seamless bonding with the insulating bonding part to enhance the strength of the cover and prevent external water from penetrating into the interior of the battery case;

   the welding part is used for welding connection with the welding support part, so that the cover and the bottom case are sealed;

   The welding bonding part is used for seamless bonding with the insulating bonding part, strengthening the strength of the cover, reducing the direct contact area between the insulating bonding part and the inside of the battery case, and preventing the penetration of external water into the battery case. inside the battery case;

   Before the cover is sealed with the bottom case, after the insulating adhesive part is melted by an insulating anti-corrosion material with a thermal shrinkage rate of 6% or less at 100° C. or more, the insulating adhesive part is melted with the conductive adhesive part. , The welding bonding part is seamlessly bonded, and the bonding strength between the conductive bonding part and the welding bonding part is greater than or equal to 1.0N per square millimeter under cooling and normal temperature. The thickness d4 of the connecting portion is 0.01mm-2.5mm, and the contact area S0 between the insulating adhesive portion and the battery case interior satisfies π*D3*D3*1/4<=S0<=π*D2*D2*1/ 8.
2. The battery case according to claim 1, wherein the material of the outer contact layer is stainless steel, the thickness d5 of the outer contact layer is 0.1mm-0.25mm; and/or the material of the inner contact layer It is stainless steel, and the thickness d6 of the inner contact layer is 0.1mm-0.25mm.
3. The battery case of claim 1, wherein the insulating layer is made of one or more of PP, PFA, PVDF, PTFE, ETFE and PVC.
4. The battery case according to claim 1, characterized in that the adhesive strength between the insulating adhesive part and the conductive adhesive part and the welding adhesive part is less than or equal to 5.0N/square at a cooling and normal temperature mm.
5. The battery case according to claim 1, wherein the area S1 of the insulating adhesive portion and the area S2 of the insulating layer satisfy S1/S2>=0.6; and/or, the area of the insulating adhesive portion is The area S1 and the area S3 of the outer contact layer satisfy S1/S3>=0.5.
6. The battery case according to any one of claims 1 to 5, wherein a first adhesion reinforcing layer is provided on the first surface layer of the conductive adhesive part close to the insulating adhesive part, which is used to strengthen the connection between the conductive adhesive part and the insulating adhesive part. and/or, a second bonding enhancement layer is provided on the second surface layer of the welding and bonding portion close to the insulating bonding portion, which is used to strengthen the bonding strength with the insulating bonding portion. Bond strength between joints.
7. The battery case according to any one of claims 1 to 5, wherein the side wall is further provided with an extension portion, the extension portion protrudes from the welding support portion and extends outward by a certain height h, and the extension portion protrudes from the welding support portion. The extension height h is equal to or greater than the sum of the thickness d4 of the insulating adhesive portion and the thickness d5 of the outer contact layer.
8. The battery case according to claim 7, characterized in that the battery case further comprises a protection member, the protection member is provided on the extension portion after the cover and the bottom case are sealed, and the protection member is formed by the welding The gap-filling liquid glue is formed by curing at room temperature between the insulating adhesive part, the insulating bonding part and the outer edge of the outer contact layer.
9. The battery case according to any one of claims 1 to 5, wherein the insulating protection part is provided with a reinforcing unit, and the reinforcing unit extends to the center and the edge of the battery case respectively, and is used for reinforcing the Fastness of the insulating layer and the inner contact layer.
10. A battery, characterized in that it comprises a battery cell and the battery case according to any one of claims 1 to 9, wherein one pole of the battery cell is electrically connected to the outer contact layer of the battery case, and the other pole is electrically connected to the outer contact layer of the battery case. It is electrically connected to the inner contact layer and/or the bottom case of the battery case.

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