Button cell and manufacturing method thereof

Abstract

The invention provides a button cell and a manufacturing method thereof, and the method comprises the steps: providing a first housing, the first housing comprises a conductive layer and an insulating layer, the middle part of the first housing is provided with a first installation groove, the insulating layer is provided with a through hole in the first installation groove, and the conductive layer is exposed out of the insulating layer in the first installation groove through the through hole; the surface of the conductive layer is coated with an active substance layer; a second pole piece is installed in a second installation groove of a second shell, and a diaphragm is placed in the second installation groove; and packaging the edges of the first shell and the second shell, and sealing the first mounting groove and the second mounting groove to form a mounting cavity, thereby obtaining the button cell. The active material layer is pre-coated on the surface of the conductive layer of the first shell, so that the problems of non-uniform thickness of the pole piece and falling of the active material layer caused by rolling of the active material layer coated on the pole piece are avoided, the gram volume is more stable, and the battery performance is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery manufacturing, and in particular to a button battery and a manufacturing method thereof. Background Art

[0002] Button batteries are mainly composed of positive or negative electrodes, separators, electrolytes, lithium sheets and outer shells. The outer shell is generally a steel shell. Button batteries are generally used for tests such as active gram capacity and first effect. Due to their large internal resistance and poor liquid retention due to their structure, it is difficult to use button batteries for other tests, and their application scenarios are limited.

[0003] The current button cell manufacturing process is: use a push-type coater to coat the pole piece with active material, roll it after coating and drying, and then punch it for assembly. This manufacturing method has obvious problems: first, the surface density of different areas of the coater fluctuates greatly, resulting in uneven thickness of the pole piece after rolling; second, after the pole piece is punched, the active material layer coated on its edge is easy to fall off. In addition, the weight of the pole piece foil also fluctuates, resulting in large fluctuations in the tested gram capacity or first-effect data. Summary of the invention

[0004] Based on this, it is necessary to provide a button battery and a manufacturing method thereof to address the above technical problems.

[0005] A method for manufacturing a button battery, comprising:

[0006] A first shell is provided, wherein the first shell includes a conductive layer and an insulating layer coated on the outside of the conductive layer, a first mounting groove is provided in the middle of the first shell, a through hole is provided in the insulating layer in the first mounting groove, the conductive layer is exposed to the insulating layer outside the first mounting groove through the through hole, an active material layer is coated on the surface of the conductive layer within the range of the first mounting groove, a first pole ear is connected to one side of the first shell, and the first pole ear is connected to the conductive layer;

[0007] Providing a second pole piece, wherein one side of the second pole piece is connected to a second pole lug;

[0008] Providing a second housing, wherein a second mounting groove is provided in the middle of the second housing;

[0009] Installing the second pole piece into the second mounting groove of the second housing, adding electrolyte into the second mounting groove, and then placing a diaphragm, wherein the width of the diaphragm is greater than the width of the second mounting groove;

[0010] Adding electrolyte dropwise into the first installation groove;

[0011] The edges of the first shell and the second shell are sealed, and the first mounting groove and the second mounting groove are sealed to form a mounting cavity, thereby obtaining a button battery.

[0012] In one embodiment, the step of encapsulating the edges of the first shell and the second shell, and sealing the first mounting groove and the second mounting groove to form a mounting cavity, to obtain a button battery includes:

[0013] The first mounting groove of the first shell is aligned with the second mounting groove, the second pole piece and the active material layer are isolated by the diaphragm, the edges of the first shell and the second shell are encapsulated, and the first mounting groove and the second mounting groove are sealed to form a mounting cavity to obtain a button battery.

[0014] In one embodiment, before the step of providing the second housing, the step further includes:

[0015] Providing a second prototype housing;

[0016] The second prototype shell is punched to form a second mounting groove in the middle of the second prototype shell to obtain the second shell, wherein the width of the second mounting groove is greater than the width of the first mounting groove.

[0017] In one embodiment, before the step of providing the first housing, the step further includes:

[0018] Providing a first prototype housing, wherein the first prototype housing comprises a conductive layer and an insulating layer covering the outer side of the conductive layer, the insulating layer has a through hole in the middle of the first prototype housing, and the conductive layer is exposed to the insulating layer through the through hole;

[0019] Punching the first prototype shell to form a first mounting groove in the middle of the first prototype shell to obtain the first shell, wherein the range of the first mounting groove coincides with the range of the through hole;

[0020] An active material slurry is applied to the surface of the conductive layer within the first mounting groove, and an active material layer is formed on the surface of the conductive layer after the active material slurry is cured.

[0021] In one embodiment, before the step of providing the first housing, the step further includes:

[0022] Providing a first prototype housing, wherein the first prototype housing comprises a conductive layer and an insulating layer covering the outer side of the conductive layer, the insulating layer has a through hole in the middle of the first prototype housing, and the conductive layer is exposed to the insulating layer through the through hole;

[0023] Coating an active material slurry on the surface of the conductive layer exposed within the through hole, and forming an active material layer on the surface of the conductive layer after the active material slurry is cured;

[0024] The first prototype shell is punched to form a first installation groove in the middle of the first prototype shell to obtain the first shell, wherein the range of the first installation groove coincides with the range of the through hole.

[0025] In one of the embodiments, the active material slurry includes an active material, a conductive agent, a binder and a dispersant, and the mass ratio of the active material, the conductive agent, the binder and the dispersant is 95.0:2.0:1.5:1.5.

[0026] In one embodiment, the conductive layer includes an aluminum layer, and the insulating layer includes a PE layer.

[0027] In one embodiment, the second pole sheet is a lithium sheet, the second pole tab is a nickel strip pole tab, and the lithium sheet is bonded to the nickel strip pole tab by conductive adhesive.

[0028] In one embodiment, the step of encapsulating the edges of the first shell and the second shell, and sealing the first mounting groove and the second mounting groove to form a mounting cavity, to obtain a button battery includes:

[0029] A conductive wire is installed on a surface of the first shell facing the diaphragm, a first end of the conductive wire is connected to the insulating layer, and a second end of the conductive wire extends to the outside of the first shell;

[0030] The first mounting groove of the first shell is aligned with the second mounting groove, the second pole piece and the active material layer are isolated by the diaphragm, the edges of the first shell and the second shell are encapsulated, the first mounting groove and the second mounting groove are sealed to form a mounting cavity, the conductive wire, the first pole ear and the second pole ear are at least partially exposed in the mounting cavity, and a button battery is obtained.

[0031] A button battery, comprising: a first shell, a second shell, a diaphragm and a second pole piece;

[0032] The first shell includes a conductive layer and an insulating layer coated on the outside of the conductive layer, a first mounting groove is arranged in the middle of the first shell, a through hole is provided in the insulating layer in the first mounting groove, the conductive layer is exposed to the insulating layer outside the first mounting groove through the through hole, an active material layer is coated on the surface of the conductive layer within the range of the first mounting groove, a first pole ear is connected to one side of the first shell, and the first pole ear is connected to the conductive layer;

[0033] One side of the second pole piece is connected to a second pole lug;

[0034] A second mounting groove is provided in the middle of the second shell;

[0035] The edges of the first shell and the second shell are sealed and connected, the first mounting groove and the second mounting groove are sealed to form a mounting cavity, the first pole ear and the second pole ear are at least partially exposed from the mounting cavity, the diaphragm and the second pole piece are arranged in the mounting cavity, wherein the second pole piece is arranged in the second mounting groove, the diaphragm is arranged on the side of the second pole piece facing away from the second shell, and the diaphragm isolates the active material layer and the second pole piece.

[0036] The button battery and its manufacturing method, by pre-coating the active material layer on the surface of the conductive layer of the first shell and using the conductive layer of the first shell as the pole piece, avoids the problem of uneven pole piece thickness and falling off of the active material layer due to rolling of the active material layer coated on the pole piece, effectively avoids the problem of large fluctuations in gram capacity caused by this, makes the gram capacity more stable, and thus effectively improves the battery performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of a process for manufacturing a button cell in one embodiment;

[0038] Figure 2 A schematic diagram of the structure of a first housing of a button-type battery in one embodiment in one direction;

[0039] Figure 3 A schematic structural diagram of a first housing of a button-type battery in another direction in one embodiment;

[0040] Figure 4 A schematic diagram of the structure of a second pole piece of a button battery in one embodiment;

[0041] Figure 5 A schematic diagram of the assembly structure of a button battery in one direction according to an embodiment;

[0042] Figure 6 A schematic diagram of the assembly structure of a button battery in another direction in one embodiment;

[0043] Figure 7 It is a structural schematic diagram of one direction of the first shell of a button battery in another embodiment.

[0044] Description of reference numerals:

[0045] 10. button cell; 210. first housing; 220. second housing; 320. second pole piece; 410. diaphragm; 211. conductive layer; 212. insulating layer; 510. first pole ear; 520. second pole ear; 213. first mounting groove; 221. second mounting groove; 250. active material layer; 610. conductive wire; DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0047] In one embodiment, Figure 1 As shown, a button battery manufacturing method is provided, which includes:

[0048] Step 110, providing a first shell, wherein the first shell includes a conductive layer and an insulating layer coated on the outside of the conductive layer, a first mounting groove is provided in the middle of the first shell, a through hole is provided in the insulating layer in the first mounting groove, the conductive layer is exposed to the insulating layer outside the first mounting groove through the through hole, an active material layer is coated on the surface of the conductive layer within the range of the first mounting groove, a first pole ear is connected to one side of the first shell, and the first pole ear is connected to the conductive layer;

[0049] Step 120, providing a second pole piece, wherein one side of the second pole piece is connected to a second pole lug;

[0050] Step 130, providing a second housing, wherein a second mounting groove is provided in the middle of the second housing;

[0051] Step 140, installing the second electrode piece into the second mounting groove of the second housing, adding electrolyte into the second mounting groove, and then placing a diaphragm, wherein the width of the diaphragm is greater than the width of the second mounting groove;

[0052] Step 150, adding electrolyte to the first installation groove;

[0053] Step 160 , encapsulating the edges of the first shell and the second shell, and sealing the first mounting groove and the second mounting groove to form a mounting cavity, thereby obtaining a button battery.

[0054] In this embodiment, the insulating layer of the first shell includes a PE (Polyethylene) layer, and the conductive layer is a metal layer, for example, the conductive layer is an aluminum layer. In this embodiment, the first shell is an aluminum-plastic film, including a first PE layer, an aluminum layer, and a second PE layer, and the first PE layer and the second PE layer are coated on the outside of the aluminum layer. In some other embodiments, the first shell can also use other insulating layer and conductive layer materials, not limited to aluminum-plastic film. The first shell is recessed to form a first mounting groove, and the insulating layer is hollowed out in the first mounting groove to form a through hole, so that the conductive layer is exposed through the through hole, and an active material layer is arranged on the exposed surface of the conductive layer.

[0055] In this embodiment, the conductive layer of the first shell serves as the first electrode of the battery. In this embodiment, since the active material layer is pre-coated on the surface of the conductive layer of the first shell, there is no need to coat the active material layer on the electrode piece, thereby avoiding the problem of uneven thickness of the electrode piece after rolling due to uneven coating of the active material layer and the problem of falling off of the active material layer after rolling.

[0056] In this embodiment, since the width of the diaphragm is greater than the width of the second mounting groove, and since the second pole piece is located in the second mounting groove, the diaphragm can fully isolate the second pole piece from the conductive layer of the first shell.

[0057] In this embodiment, the conductive layer of the first shell and the second pole piece can be a positive pole or a negative pole, for example, the conductive layer of the first shell is a positive pole, and the second pole piece is a negative pole, for example, the conductive layer of the first shell is a negative pole, and the second pole piece is a positive pole. In one embodiment, the second pole piece is a lithium sheet. In this embodiment, the conductive layer of the first shell is used as a positive pole piece, and the second pole piece is a negative lithium sheet. The second pole piece can also be called a lithium sheet. The second pole ear is a nickel strip pole ear. In this embodiment, the lithium sheet is bonded to the nickel strip pole ear through a conductive adhesive. Specifically, the nickel strip pole ear is used to lead out the conduction. The conductive adhesive includes an adhesive and a conductive filler, wherein the adhesive includes at least one of epoxy resin, silicone resin, polyimide resin, phenolic resin, polyurethane and acrylic resin, and the conductive adhesive does not contain water. The conductive filler can be gold, silver, copper, aluminum, zinc, iron, nickel powder and / or graphite and some conductive compounds, but is not limited thereto.

[0058] In this embodiment, the first shell is connected to the first pole ear, and the second pole piece is connected to the second pole ear. When the first shell and the second shell enclose the second pole piece and the diaphragm in the installation cavity, the first pole ear and the second pole ear are exposed on the outside of the first shell and the second shell. Subsequently, the first shell and the second shell are thermoplastically packaged to obtain a button battery.

[0059] In the above embodiment, the active material layer is pre-coated on the surface of the conductive layer of the first shell and the conductive layer of the first shell is used as the pole piece, thereby avoiding the problem of uneven pole piece thickness and falling off of the active material layer due to rolling of the active material layer coated on the pole piece, and effectively avoiding the problem of large fluctuations in gram capacity caused by this, making the gram capacity more stable, thereby effectively improving the battery performance.

[0060] In one embodiment, the cross-sectional shape of the first mounting groove is a trapezoid. In this embodiment, the cross-sectional shape of the first mounting groove in the direction perpendicular to the conductive layer is a trapezoid. In this embodiment, the depth of the first mounting groove gradually increases from the edge to the middle, and the side wall of the first mounting groove gradually tilts from the outside to the inside toward the bottom of the first mounting groove, so that the cross-sectional shape of the first mounting groove is trapezoidal. For the first shell that is first coated with the active material layer and then stamped, when the first shell is stamped, the conductive layer can be gradually deformed from the outside to the inside, and the waist of the trapezoid can make the depth of the first mounting groove gradually transition and deepen, avoiding large-angle (90-degree) deformation of the conductive layer, thereby effectively preventing the active material layer on the conductive layer from falling off during stamping.

[0061] In one embodiment, the shape of the through hole is circular. In this embodiment, the cross-sectional shape of the first mounting groove in the direction parallel to the conductive layer is circular. In this embodiment, the circular through hole and the first mounting groove can better adapt to the shape of the circular second pole piece and the diaphragm. In other embodiments, the shape of the through hole can also be a triangle, a square, or a regular polygon. The cross-sectional shape of the first mounting groove in the direction parallel to the conductive layer can also be a triangle, a square, or a regular polygon.

[0062] In one embodiment, the steps of encapsulating the edges of the first shell and the second shell, and sealing the first mounting groove and the second mounting groove to form a mounting cavity, to obtain a button battery include:

[0063] The first mounting groove of the first shell is aligned with the second mounting groove, the second pole piece and the active material layer are isolated by the diaphragm, the edges of the first shell and the second shell are encapsulated, and the first mounting groove and the second mounting groove are sealed to form a mounting cavity to obtain a button battery.

[0064] In this embodiment, the opening direction of the first mounting groove of the first shell is oriented toward the opening direction of the second mounting groove so that the first mounting groove and the second mounting groove can be aligned, and then the first shell and the second shell are thermoplastic packaged to seal the second pole piece, the diaphragm and the electrolyte in the installation cavity, and the diaphragm isolates the second pole piece and the conductive layer serving as the first electrode, thereby obtaining a button battery.

[0065] In one embodiment, before the step of providing a second shell, the step also includes: providing a second prototype shell; stamping the second prototype shell to form a second mounting groove in the middle of the second prototype shell to obtain the second shell, wherein the width of the second mounting groove is greater than the width of the first mounting groove.

[0066] In this embodiment, the second prototype shell includes a conductive prototype layer and an insulating prototype layer coated on the outside of the conductive prototype layer. For example, the second prototype shell can be an aluminum-plastic film, for example, the second prototype shell includes a third PE layer, an aluminum prototype layer and a fourth PE layer, and the third PE layer and the fourth PE layer are coated on the outside of the aluminum prototype layer. In some other embodiments, the first shell can also use other insulating layers and conductive layers, not limited to aluminum-plastic films. In this embodiment, the second prototype shell is stamped to form a second mounting groove with a width greater than the first mounting groove on the second prototype shell, and the depth of the second mounting groove is less than the thickness of the second pole piece. In this way, when the second pole piece is placed in the second mounting groove, the second pole piece at least partially protrudes onto the second mounting groove, and then a diaphragm is placed on the second pole piece. Since the width of the diaphragm is greater than the width of the second mounting groove, the second pole piece can be effectively blocked by the diaphragm, and the second pole piece and the conductive layer of the first shell are isolated.

[0067] In one embodiment, before the step of providing the first housing, the step further includes:

[0068] Providing a first prototype housing, wherein the first prototype housing comprises a conductive layer and an insulating layer covering the outer side of the conductive layer, the insulating layer has a through hole in the middle of the first prototype housing, and the conductive layer is exposed to the insulating layer through the through hole;

[0069] Punching the first prototype shell to form a first mounting groove in the middle of the first prototype shell to obtain the first shell, wherein the range of the first mounting groove coincides with the range of the through hole;

[0070] An active material slurry is applied to the surface of the conductive layer within the first mounting groove, and an active material layer is formed on the surface of the conductive layer after the active material slurry is cured.

[0071] In this embodiment, the first prototype shell includes a conductive layer and an insulating layer coated on the outside of the conductive layer. In this embodiment, the first prototype shell is an aluminum-plastic film, including a first PE layer, an aluminum layer and a second PE layer, the first PE layer and the second PE layer are coated on the outside of the aluminum layer, and before providing the first prototype shell, the first PE layer in the middle of the first prototype shell is first removed to form a through hole in the middle of one side of the first prototype shell, so that the aluminum layer is exposed to the insulating layer through the through hole. Subsequently, the middle of the first prototype shell is stamped to form a first mounting groove in the middle of the first prototype shell to obtain the first shell, and the position and range of the first mounting groove coincide with the position and range of the through hole. In this embodiment, a cylindrical pressure column is used to press down first and then rotate and roll to press to press out the first mounting groove on the first prototype shell.

[0072] Subsequently, the surface of the exposed conductive layer in the first installation groove is coated with active material slurry, and then the first shell is placed in an oven below 120° C. to dry it, thereby forming an active material layer on the surface of the conductive layer. In this embodiment, the first prototype shell is first stamped, and then the active material slurry is coated to form the active material layer, which can effectively prevent the active material layer from falling off during the stamping process, thereby effectively ensuring the integrity of the active material layer.

[0073] In one embodiment, before the step of providing the first housing, the step further includes:

[0074] Providing a first prototype housing, wherein the first prototype housing comprises a conductive layer and an insulating layer covering the outer side of the conductive layer, the insulating layer has a through hole in the middle of the first prototype housing, and the conductive layer is exposed to the insulating layer through the through hole;

[0075] Coating an active material slurry on the surface of the conductive layer exposed within the through hole, and forming an active material layer on the surface of the conductive layer after the active material slurry is cured;

[0076] The first prototype shell is punched to form a first installation groove in the middle of the first prototype shell to obtain the first shell, wherein the range of the first installation groove coincides with the range of the through hole.

[0077] In this embodiment, a first prototype shell that is the same as that in the above embodiment is provided. The difference from the previous embodiment is that, in this embodiment, an active material slurry is first coated on the surface of the exposed conductive layer, and after drying, an active material layer is formed on the surface of the conductive layer. Subsequently, the middle portion of the first prototype shell is punched, and the punching range coincides with the position and range of the through hole, thereby forming a first mounting groove on the first shell whose position and range coincide with the through hole.

[0078] In one embodiment, the active material slurry includes an active material, a conductive agent, a binder, and a dispersant, and the mass ratio of the active material, the conductive agent, the binder, and the dispersant is 95.0:2.0:1.5:1.5.

[0079] In one embodiment, the steps of encapsulating the edges of the first shell and the second shell, and sealing the first mounting groove and the second mounting groove to form a mounting cavity, to obtain a button battery include:

[0080] A conductive wire is installed on a surface of the first shell facing the diaphragm, a first end of the conductive wire is connected to the insulating layer, and a second end of the conductive wire extends to the outside of the first shell;

[0081] The first mounting groove of the first shell is aligned with the second mounting groove, the second pole piece and the active material layer are isolated by the diaphragm, the edges of the first shell and the second shell are encapsulated, the first mounting groove and the second mounting groove are sealed to form a mounting cavity, the conductive wire, the first pole ear and the second pole ear are at least partially exposed in the mounting cavity, and a button battery is obtained.

[0082] In this embodiment, the conductive wire is used as the third electrode of the button battery to provide signal transmission to monitor the electrochemical behavior of the active material of the battery, including potential, platform, etc. In addition, other tests can be expanded by using the conductive wire. In this embodiment, the conductive wire is first installed on the first shell, the first end of the conductive wire is connected to the insulating layer of the first shell, and the second end of the conductive wire extends to the outside of the first shell. During the packaging process of the first shell and the second shell, the second end of the conductive wire and the end of the first pole ear away from the first shell and the end of the second pole ear away from the second pole piece are exposed to the installation cavity, so that the second end of the conductive wire, the end of the first pole ear away from the first shell, and the end of the second pole ear away from the second pole piece extend to the outside of the first shell and the second shell, which is convenient for connecting with external electrical components. In this way, the battery signal can be monitored through the conductive wire. In one embodiment, the conductive wire is a copper wire with a diameter of 30 to 60 um. In this embodiment, the copper wire is fixedly bonded to the insulating layer of the first shell by an electrolyte-resistant tape to avoid the copper wire from connecting to the active material layer. After packaging, a button battery with three electrodes is formed. The copper wire can be used to monitor the electrochemical behavior of the active materials in the battery, such as potential and platform.

[0083] The following are specific embodiments:

[0084] Embodiment 1:

[0085] 1. The active material slurry is prepared by preparing the slurry in a certain ratio, such as: active material: conductive agent: binder: dispersant = 95.0:2.0:1.5:1.5, but not limited to this formula.

[0086] 2. Weigh the weight of the shell A, and use a dropper to transfer the slurry to the shell A. The shell A has a lead-out pole ear for conducting electricity, and then put it in an oven below 120°C to dry it, making a pole piece of a special shape, and then weigh it to get the weight of the dressing. Figure 1 ) The material is mainly aluminum-plastic film (generally a structure of PE layer + aluminum + PE layer, but not limited to this type of aluminum-plastic film), the inner PE layer is provided with a hollow circular area with a diameter of a, and a punching device is used to punch a hole, and the punching depth is HA. The hollow area is not limited to a circle, and can also be a triangle or a square.

[0087] 3. Roll the pole piece, use a special pressure column, apply a certain pressure, first press down and then rotate and roll (such as Figure 2 ), the compaction density is determined by different materials, and a roller press can also be used to perform rolling in a conventional manner, and the weight can be weighed again after rolling to confirm the weight.

[0088] 4. The lithium sheet and the nickel strip tab are bonded with conductive adhesive (such as Figure 3 ), the nickel strip tab is used for conducting, the conductive adhesive is an adhesive system such as epoxy resin, silicone resin, polyimide resin, phenolic resin, polyurethane, acrylic resin, etc., which does not contain water, and the conductive filler can be gold, silver, copper, aluminum, zinc, iron, nickel powder and graphite and some conductive compounds, but not limited to these.

[0089] 5. Assembly of snap-on switch: ① Use aluminum plastic film to punch out the shell B ( Figure 4 ), the diameter of the punching hole is b, b>a is required, and the punching hole depth HB<the thickness of the lithium sheet; ② put in the lithium sheet with the pole ear, drip the electrolyte on the lithium sheet, put in the diaphragm, wait for the diaphragm to be fully wetted, and the diaphragm size c>b; ③ use the special pole piece with "3" roller pressing, drip the electrolyte on the surface to wet it; ④ combine the shell A and the shell B, use the edge sealing machine to thermoplastically encapsulate the two, and obtain the button battery. ( Figure 5 )

[0090] 6. Test: After assembly, let it stand for 4 to 8 hours, use a clamp to apply a certain pressure, clamp the large surface of the buckle for testing.

[0091] Embodiment 2:

[0092] 1. Based on the battery manufactured in Example 1, a three-electrode buckle assembly is performed using a buried copper wire method, which can be used to monitor the electrochemical behavior of active substances, including potential, platform, etc., and can also be extended to other tests.

[0093] 2. Assembly of buckle battery: ① Use aluminum plastic film to punch out the shell B, the diameter of the punching hole is b, b>a, and the punching hole depth HB<thickness of lithium sheet; ② Put in the lithium sheet with pole ear, drip electrolyte on the lithium sheet, put in the diaphragm, wait for the diaphragm to be fully wetted, and the diaphragm size c>b; ③ Use the special pole piece with "3" roller pressing, drip electrolyte on the surface to wet it; ④ Pre-embed a 30~60um copper wire in the shell A, and fix the copper wire with electrolyte-resistant tape. The copper wire cannot exceed the active material area ( Figure 6 ⑤ Combine the shell A and the shell B, and use an edge sealing machine to thermoplastically seal the two to obtain the three-electrode button battery.

[0094] 3. Test: After assembly, let it stand for 4 to 8 hours, use a clamp to apply a certain pressure, clamp the large surface of the buckle for testing.

[0095] Embodiment three:

[0096] 1. Furthermore, this structure can be used to make small single-chip batteries, which have the advantages of small size, low material loss, and fast production.

[0097] 2. Use the cut single-sided electrode sheet, the size of the positive electrode sheet is less than the positive electrode sheet (i.e. the electrode sheet with single-sided dressing), and use conductive glue to bond the electrode ear to the non-dressing area, refer to Figure 3 .

[0098] 3. Assembly of single-chip button-type battery: ① Use aluminum-plastic film to punch out shells A and B, with the diameters of the punching holes being a and b respectively, requiring b>a, and the punching hole depth H<pole thickness; ② Place the pole piece with pole ears, drip electrolyte on the pole piece, place the diaphragm, and wait for the diaphragm to be fully moistened, with the diaphragm size c>b; ③ Combine shell A and shell B, and use an edge sealing machine to thermoplastically encapsulate the two to obtain the small single-chip button-type battery.

[0099] In one embodiment, Figures 2 to 6As shown, a button battery 10 is provided, comprising a first shell 210, a second shell 220, a diaphragm 410 and a second pole piece 320; the first shell 210 comprises a conductive layer 211 and an insulating layer 212 coated on the outside of the conductive layer 211, a first mounting groove 213 is arranged in the middle of the first shell 210, a through hole is provided in the insulating layer 212 in the first mounting groove 213, the conductive layer 211 is exposed to the insulating layer 212 in the first mounting groove 213 through the through hole, the surface of the conductive layer 211 is coated with an active material layer 250 within the range of the first mounting groove 213, a first pole ear 510 is connected to one side of the first shell 210, and the first pole ear 510 is connected to the conductive layer 211; One side of the second pole piece 320 is connected to the second pole ear 520; a second mounting groove 221 is provided in the middle of the second shell 220; the edges of the first shell 210 and the second shell 220 are sealed and connected, the first mounting groove 213 and the second mounting groove 221 are sealed to form a mounting cavity, the first pole ear 510 and the second pole ear 520 are at least partially exposed in the mounting cavity, the diaphragm 410 and the second pole piece 320 are arranged in the mounting cavity, wherein the second pole piece 320 is arranged in the second mounting groove 221, the diaphragm 410 is arranged on the side of the second pole piece 320 facing away from the second shell 220, and the diaphragm 410 isolates the active material layer 250 and the second pole piece 320.

[0100] In this embodiment, the conductive layer 211 of the first shell 210 serves as the first electrode, and an electrolyte is provided between the second pole piece 320 and the diaphragm 410, and between the first shell 210 and the diaphragm 410. The diaphragm will serve as the conductive layer of the first motor and the second pole piece 320 to isolate each other. After the first shell 210 and the second shell 220 are thermoplastically packaged, the first mounting groove 213 and the second mounting groove 221 are connected and the outer edges are sealed to form a mounting cavity to encapsulate the diaphragm 410, the second pole piece 320 and the electrolyte. The first shell 210 is recessed to form the first mounting groove 213, and the insulating layer 212 is hollowed out in the first mounting groove 213 to form a through hole, so that the conductive layer 211 is exposed through the through hole, and the active material layer 250 is provided on the exposed surface of the conductive layer 211.

[0101] In this embodiment, the active material layer 250 is arranged on the surface of the conductive layer 211 of the first shell 210, which avoids the problem of uneven thickness of the electrode sheet and falling off of the active material layer 250 due to the active material layer 250 being rolled on the electrode sheet, and effectively avoids the problem of large fluctuations in gram capacity caused by this, making the gram capacity more stable, thereby effectively improving battery performance.

[0102] In one embodiment, the first shell 210 is configured such that: the conductive layer 211 includes an aluminum layer; and / or the insulating layer 212 includes a PE layer.

[0103] In this embodiment, the insulating layer 212 of the first shell 210 includes a PE (Polyethylene) layer, and the conductive layer 211 is a metal layer, for example, the conductive layer 211 is an aluminum layer. In this embodiment, the first shell 210 is an aluminum-plastic film, including a first PE layer, an aluminum layer, and a second PE layer, and the first PE layer and the second PE layer are coated on the outside of the aluminum layer. In some other embodiments, the first shell 210 can also use other materials for the insulating layer 212 and the conductive layer 211, not limited to the aluminum-plastic film.

[0104] In one embodiment, Figure 6 As shown, the width of the diaphragm 410 is greater than the width of the second mounting groove 221. In this embodiment, since the width of the diaphragm 410 is greater than the width of the second mounting groove 221, and since the second pole piece 320 is located in the second mounting groove 221, the diaphragm 410 can fully isolate the second pole piece 320 from the first housing 210 serving as the first pole piece.

[0105] In one embodiment, Figure 3 and Figure 6 As shown, the cross-sectional shape of the first mounting groove 213 is a trapezoid. In this embodiment, the cross-sectional shape of the first mounting groove 213 in the direction perpendicular to the conductive layer 211 is a trapezoid. In this embodiment, the depth of the first mounting groove 213 gradually increases from the edge to the middle, and the side wall of the first mounting groove 213 gradually tilts from the outside to the inside toward the bottom of the first mounting groove 213, so that the cross-sectional shape of the first mounting groove 213 is set in a trapezoidal shape. In this way, for the first shell 210 that is stamped after the active material layer 250 is coated first, when the first shell 210 is stamped, the conductive layer 211 can be gradually deformed from the outside to the inside, and the waist of the trapezoid can make the depth of the first mounting groove 213 gradually transition and deepen, avoiding the large-angle (90-degree) deformation of the conductive layer 211, thereby effectively preventing the active material layer 250 on the conductive layer 211 from falling off during stamping.

[0106] In one embodiment, the second pole sheet 320 and the second pole tab 520 are configured as follows: the second pole sheet 320 is a lithium sheet; and / or the second pole tab 520 is a nickel strip pole tab; and / or the second pole sheet 320 is bonded to the second pole tab 520 by conductive adhesive.

[0107] In this embodiment, the first pole piece (the conductive layer of the first shell 210) and the second pole piece 320 can be a positive pole or a negative pole. For example, the conductive layer of the first shell 210 is a positive pole and the second pole piece 320 is a negative pole. For example, the conductive layer of the first shell 210 is a negative pole and the second pole piece 320 is a positive pole. In one embodiment, the second pole piece 320 is a lithium sheet. In this embodiment, the conductive layer of the first shell 210 is a positive pole piece, and the second pole piece 320 is a negative lithium sheet. The second pole piece 320 can also be called a lithium sheet. The second pole ear 520 is a nickel strip pole ear. In this embodiment, the lithium sheet is bonded to the nickel strip pole ear by a conductive adhesive. Specifically, the nickel strip pole ear is used to lead out the conduction. The conductive adhesive includes an adhesive and a conductive filler. The adhesive includes at least one of epoxy resin, silicone resin, polyimide resin, phenolic resin, polyurethane and acrylic resin, and the conductive adhesive does not contain water. The conductive filler can be gold, silver, copper, aluminum, zinc, iron, nickel powder and / or graphite and some conductive compounds, but is not limited to this.

[0108] In one embodiment, Figure 6 As shown, the width of the second mounting groove 221 is greater than the width of the first mounting groove 213. In this way, the area of ​​the second mounting groove 221 is greater than the area of ​​the first mounting groove 213, which is conducive to the second mounting groove 221 to better accommodate the second pole piece 320.

[0109] In one embodiment, Figure 6 As shown, the depth of the second mounting groove 221 is less than the thickness of the second pole piece 320 .

[0110] In this embodiment, the depth of the second mounting groove 221 is less than the thickness of the second pole piece 320. Thus, when the second pole piece 320 is placed in the second mounting groove 221, the second pole piece 320 at least partially protrudes onto the second mounting groove 221. Subsequently, the diaphragm 410 is placed on the second pole piece 320. Since the width of the diaphragm 410 is greater than the width of the second mounting groove 221, the diaphragm 410 can effectively block the second pole piece 320, thereby isolating the second pole piece 320 from the conductive layer of the first shell 210.

[0111] In one embodiment, the through hole is circular in shape, and the cross-sectional shape of the first mounting groove 213 in a direction parallel to the conductive layer 211 is circular. In this embodiment, the circular through hole and the first mounting groove 213 can better fit the shape of the circular diaphragm 410. In other embodiments, the through hole can also be in the shape of a triangle, a square, or a regular polygon, and the cross-sectional shape of the first mounting groove 213 in a direction parallel to the conductive layer 211 can also be in the shape of a triangle, a square, or a regular polygon.

[0112] In one embodiment, Figure 7As shown, the button battery 10 further includes a conductive wire 610, a first end of the conductive wire 610 is connected to a side of the insulating layer 212 facing the diaphragm, and a second end of the conductive wire 610 extends to the outside of the first shell 210 and the second shell 220. In this embodiment, the conductive wire 610 serves as the third electrode of the button battery 10, and is used to provide signal transmission to monitor the electrochemical behavior of the active material of the battery, including potential, platform, etc. In addition, other tests can be expanded using the conductive wire 610. In this embodiment, the conductive wire 610 is first installed on the first shell 210, the first end of the conductive wire 610 is connected to the insulating layer 212 of the first shell 210, and the second end of the conductive wire 610 extends to the outside of the first shell 210. During the packaging process of the first shell 210 and the second shell 220, the second end of the conductive wire 610 and the end of the first pole ear 510 away from the first shell 210 and the end of the second pole ear 520 away from the second pole piece 320 are exposed to the installation cavity, so that the second end of the conductive wire 610, the end of the first pole ear 510 away from the first shell 210, and the end of the second pole ear 520 away from the second pole piece 320 extend to the outside of the first shell 210 and the second shell 220, which is convenient for connection with external electrical components. In this way, the battery signal can be monitored through the conductive wire 610. In one embodiment, the conductive wire 610 is a copper wire with a diameter of 30 to 60 um. In this embodiment, the copper wire is fixedly bonded to the insulating layer 212 of the first shell 210 using an electrolyte-resistant tape to prevent the copper wire from being connected to the active material layer 250. After packaging, a three-electrode button battery 10 is formed. The copper wire can be used to monitor the electrochemical behavior of the active material of the battery, such as potential, platform, etc.

[0113] Performance parameter comparison:

[0114] This section compares the gram capacity and internal resistance of the button batteries prepared in Example Groups 1 and 2 and Control Groups 1 and 2, respectively. Example Groups 1 and 2 are manufactured using the button battery structure and button battery manufacturing method in the above-mentioned embodiments, and Control Groups 1 and 2 are button batteries with traditional steel shell structures. The comparison results are shown in Tables 1 and 2.

[0115] In this application, the manufacturing method of the positive / negative electrode sheets of the traditional steel shell battery is changed, the surface density is more accurate, and the punching step is omitted, so there is no risk of sheet drop, thereby improving the accuracy of gram capacity and first efficiency and reducing test fluctuations:

[0116] Table 1 Comparison of gram capacity between control group and example group

[0117]

[0118]

[0119] As can be seen from Table 1, the difference (range) between the minimum gram capacity value and the maximum gram capacity value in the embodiment group is significantly smaller than that in the control group, and the fluctuation of gram capacity is significantly smaller.

[0120] In addition, since there is no need to use a traditional current collector, the active material is directly adhered to the shell, and the lithium sheet is connected to the nickel strip tab by using a conductive glue to reduce the internal resistance of the battery; the internal resistance test method is to test it through an internal resistance instrument or use an electrochemical workstation to take the resistance value of 1000Hz, but not limited to this:

[0121] Table 2 Comparison of internal resistance values ​​between control group and example group

[0122]

[0123] It can be seen from Table 2 that the mean internal resistance in the embodiment group is significantly smaller than that in the control group.

[0124] In addition, the button battery structure with conductive wires in this application can more easily produce a three-electrode button battery for monitoring the potential change of the positive or negative electrode material during the charge and discharge process. The structure is more sealed than the traditional steel shell structure, so it can better retain liquid. In addition, with the reduction of internal resistance, the button battery can be used for more electrical performance tests, such as cycle testing, etc. The button battery production cycle is short, and the button battery can be used for rapid screening of material properties, with a wider range of application scenarios.

[0125] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0126] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for manufacturing a button battery, characterized in that: include: A first shell is provided, wherein the first shell includes a conductive layer and an insulating layer coated on the outside of the conductive layer, a first mounting groove is provided in the middle of the first shell, a through hole is provided in the insulating layer in the first mounting groove, the conductive layer is exposed to the insulating layer outside the first mounting groove through the through hole, an active material layer is coated on the surface of the conductive layer within the range of the first mounting groove, a first pole ear is connected to one side of the first shell, and the first pole ear is connected to the conductive layer; Providing a second pole piece, wherein one side of the second pole piece is connected to a second pole lug; Providing a second housing, wherein a second mounting groove is provided in the middle of the second housing; Installing the second pole piece into the second mounting groove of the second housing, adding electrolyte into the second mounting groove, and then placing a diaphragm, wherein the width of the diaphragm is greater than the width of the second mounting groove; Adding electrolyte dropwise into the first installation groove; The edges of the first shell and the second shell are sealed, and the first mounting groove and the second mounting groove are sealed to form a mounting cavity, thereby obtaining a button battery.

2. The method according to claim 1, characterized in that The step of encapsulating the edges of the first shell and the second shell, and sealing the first mounting groove and the second mounting groove to form a mounting cavity to obtain a button battery comprises: The first mounting groove of the first shell is aligned with the second mounting groove, the second pole piece and the active material layer are isolated by the diaphragm, the edges of the first shell and the second shell are encapsulated, and the first mounting groove and the second mounting groove are sealed to form a mounting cavity to obtain a button battery.

3. The method according to claim 1, characterized in that: Before the step of providing the second housing, the step further includes: Providing a second prototype housing; The second prototype shell is punched to form a second mounting groove in the middle of the second prototype shell to obtain the second shell, wherein the width of the second mounting groove is greater than the width of the first mounting groove.

4. The method according to claim 1, characterized in that Before the step of providing the first housing, the step further includes: Providing a first prototype housing, wherein the first prototype housing comprises a conductive layer and an insulating layer covering the outer side of the conductive layer, the insulating layer has a through hole in the middle of the first prototype housing, and the conductive layer is exposed to the insulating layer through the through hole; Punching the first prototype shell to form a first mounting groove in the middle of the first prototype shell to obtain the first shell, wherein the range of the first mounting groove coincides with the range of the through hole; An active material slurry is applied to the surface of the conductive layer within the first mounting groove, and an active material layer is formed on the surface of the conductive layer after the active material slurry is cured.

5. The method according to claim 1, characterized in that Before the step of providing the first housing, the step further includes: Providing a first prototype housing, wherein the first prototype housing comprises a conductive layer and an insulating layer covering the outer side of the conductive layer, the insulating layer has a through hole in the middle of the first prototype housing, and the conductive layer is exposed to the insulating layer through the through hole; Coating an active material slurry on the surface of the conductive layer exposed within the through hole, and forming an active material layer on the surface of the conductive layer after the active material slurry is cured; The first prototype shell is punched to form a first installation groove in the middle of the first prototype shell to obtain the first shell, wherein the range of the first installation groove coincides with the range of the through hole.

6. The method according to claim 1, characterized in that The active material slurry includes an active material, a conductive agent, a binder and a dispersant, and the mass ratio of the active material, the conductive agent, the binder and the dispersant is 95.0:2.0:1.5:1.

5.

7. The method according to claim 1, characterized in that The conductive layer includes an aluminum layer, and the insulating layer includes a PE layer.

8. The method according to claim 1, characterized in that The second pole piece is a lithium plate, the second pole tab is a nickel strip pole tab, and the lithium plate is bonded to the nickel strip pole tab by conductive adhesive.

9. The method according to any one of claims 1 to 8, characterized in that The step of encapsulating the edges of the first shell and the second shell, and sealing the first mounting groove and the second mounting groove to form a mounting cavity to obtain a button battery comprises: A conductive wire is installed on a surface of the first shell facing the diaphragm, a first end of the conductive wire is connected to the insulating layer, and a second end of the conductive wire extends to the outside of the first shell; The first mounting groove of the first shell is aligned with the second mounting groove, the second pole piece and the active material layer are isolated by the diaphragm, the edges of the first shell and the second shell are encapsulated, the first mounting groove and the second mounting groove are sealed to form a mounting cavity, the conductive wire, the first pole ear and the second pole ear are at least partially exposed in the mounting cavity, and a button battery is obtained.

10. A button battery, characterized in that: include: a first shell, a second shell, a diaphragm, and a second pole piece; The first shell includes a conductive layer and an insulating layer coated on the outside of the conductive layer, a first mounting groove is arranged in the middle of the first shell, a through hole is provided in the insulating layer in the first mounting groove, the conductive layer is exposed to the insulating layer outside the first mounting groove through the through hole, an active material layer is coated on the surface of the conductive layer within the range of the first mounting groove, a first pole ear is connected to one side of the first shell, and the first pole ear is connected to the conductive layer; One side of the second pole piece is connected to a second pole lug; A second mounting groove is provided in the middle of the second shell; The edges of the first shell and the second shell are sealed and connected, the first mounting groove and the second mounting groove are sealed to form a mounting cavity, the first pole ear and the second pole ear are at least partially exposed from the mounting cavity, the diaphragm and the second pole piece are arranged in the mounting cavity, wherein the second pole piece is arranged in the second mounting groove, the diaphragm is arranged on the side of the second pole piece facing away from the second shell, and the diaphragm isolates the active material layer and the second pole piece.

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