Button type lithium-manganese battery

Abstract

The utility model discloses a button type lithium-manganese battery. A positive electrode comprises a positive electrode cup shell, a positive electrode active cake arranged in the positive electrode cup shell and a current collecting net positioned between the positive electrode cup shell and the positive electrode active cake; the positive electrode active cake comprises a sleeve cup and a positive electrode active material which is pressed and formed in the sleeve cup; the negative electrode comprises a negative electrode cup cover and a negative electrode active cake arranged in the negative electrode cup cover; the sealing ring is positioned between the cathode cup cover and the anode cup shell for surrounding connection of the cathode cup cover and the anode cup shell; the diaphragm is positioned between the negative active cake and the positive active cake; the cathode cup cover is provided with a top wall, a flanging peripheral wall and a transition connecting wall; the transition connecting wall is an arc-shaped wall and is provided with two continuous transition R-angle connecting positions, and the two transition R-angle connecting positions of the transition connecting wall are connected with the top wall and the peripheral wall of the folded edge respectively; wherein the top wall of the negative electrode cup cover is in a necking shape, and the diameter of the outer edge of the top wall is smaller than 2 mm compared with the retraction distance of the peripheral wall of the folded edge. The utility model has the advantages of compact structure and good sealing performance.

Description

Technical Field

[0001] The utility model relates to the field of batteries, in particular to a button-type lithium-manganese battery. Background Art

[0002] With the rapid development of science and technology, electronic products are developing very rapidly. The operation and use of electronic products must be driven by electrical energy conversion. Usually, lithium manganese primary batteries are used as power sources in electronic products. Lithium manganese primary batteries have the advantages of relatively stable voltage output, no charge and discharge effect of primary batteries, and can prevent radio wave interference, and have good application prospects.

[0003] With the advancement of modernization, battery products also need to adapt to the development of current electronic products. They must not only be lightweight, portable and easy to replace, but also have high power output and no radio interference. In addition, some electronic products also require a stable voltage power supply, especially the driving power supply for the database collection at the back end of high-end medical instruments, which has particularly strict requirements on the stability of the voltage power supply and high power output.

[0004] However, the button-type lithium manganese battery in the prior art has the disadvantage of poor sealing of the seal, especially the sealing structure is prone to failure during high power output, and has the defect of poor stability; therefore, it is necessary to improve the lithium manganese battery in the prior art to meet the needs of modern new electronic application scenarios. Utility Model Content

[0005] The main purpose of the utility model is to provide a button-type lithium manganese battery with compact structure and good sealing.

[0006] In order to achieve the above main purpose, the utility model provides a button-type lithium manganese battery, including a positive electrode, a negative electrode, a diaphragm and a sealing ring;

[0007] The positive electrode includes a positive electrode cup shell, a positive electrode active cake disposed in the positive electrode cup shell, and a current collecting network located between the positive electrode cup shell and the positive electrode active cake; the positive electrode active cake includes a sleeve cup and a positive electrode active material pressed and formed in the sleeve cup;

[0008] The negative electrode includes a negative electrode cup cover and a negative electrode active cake arranged in the negative electrode cup cover;

[0009] The sealing ring is located between the negative electrode cup cover and the positive electrode cup shell to connect the two in a circumferential manner; the diaphragm is located between the negative electrode active cake and the positive electrode active cake;

[0010] The negative electrode cup cover has a top wall, a folded peripheral wall and a transition connecting wall; the transition connecting wall is an arc-shaped wall, which has two continuous transition R-angle connecting positions, and the two transition R-angle connecting positions of the transition connecting wall are respectively connected to the top wall and the folded peripheral wall; wherein, the top wall of the negative electrode cup cover is in a constricted shape, and the outer edge diameter of the top wall is less than 2 mm indented compared to the folded peripheral wall.

[0011] According to a specific implementation of the present invention, the outer edge diameter of the top wall is retracted by less than 1 mm compared to the outer peripheral wall of the folded edge.

[0012] According to a specific embodiment of the utility model, the sheet thickness of the negative electrode cover cup is 0.10mm-0.50mm; wherein, the indentation distance of the outer edge diameter of the top wall compared to the folded edge peripheral wall is 1.5-3 times the sheet thickness of the negative electrode cup cover.

[0013] Furthermore, the indentation distance of the outer edge diameter of the top wall compared to the outer peripheral wall of the folded edge is twice the thickness of the sheet material of the negative electrode cup cover.

[0014] Furthermore, the sheet thickness of the negative electrode cover cup is 0.20 mm to 0.30 mm.

[0015] According to a specific embodiment of the utility model, the diaphragm is a bowl-shaped diaphragm with a lower opening; wherein the lower edge of the diaphragm intersects with the sealing ring, and the intersection length between the lower edge of the diaphragm and the sealing ring is set to be no less than 0.5 mm.

[0016] According to a specific embodiment of the utility model, the sleeve cup has a bottom wall and a convex thorn portion arranged on the bottom wall, and the convex thorn portion is arranged to be inserted into the positive electrode active material.

[0017] Furthermore, the burr portion is assembled on the bottom wall or formed as one piece with the bottom wall.

[0018] According to a specific embodiment of the present invention, the bottom wall has a through hole, and the positive electrode active material is filled into the hole when the positive electrode active material is pressed and formed into the sleeve cup.

[0019] According to a specific embodiment of the present invention, a concave pattern area is provided on the upper surface of the bottom wall facing the positive electrode active material, and the positive electrode active material is filled into the concave pattern area when the positive electrode active material is pressed and formed into the sleeve cup.

[0020] The utility model has the following beneficial effects:

[0021] The top wall of the negative electrode cup cover in the utility model is in a constricted shape, and the outer edge diameter of the top wall is less than 2 mm indented compared to the outer peripheral wall of the folded edge. Under this structure, the opening part of the positive electrode cup shell can achieve better sealing when radially indented, which is beneficial to maintaining the high power output of the battery. It has the advantages of compact structure, high yield rate of sealing molding and good stability.

[0022] In order to more clearly illustrate the purpose, technical solutions and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural diagram of an embodiment of a button-type lithium manganese battery of the utility model;

[0024] Figure 2 This is a structural diagram of the negative electrode cup cover in the embodiment of the button-type lithium manganese battery of the utility model;

[0025] Figure 3 This is a structural diagram of the sealing ring in the embodiment of the button-type lithium manganese battery of the utility model;

[0026] Figure 4 This is a structural diagram of the positive electrode cup shell in the embodiment of the button-type lithium manganese battery of the utility model;

[0027] Figure 5 This is a structural diagram of the current collecting network in the embodiment of the button-type lithium manganese battery of the utility model;

[0028] Figure 6 This is a structural diagram of the positive electrode active cake in the embodiment of the button-type lithium manganese battery of the utility model;

[0029] Figure 7 It is a top view of the sleeve cup in the embodiment of the button-type lithium manganese battery of the utility model;

[0030] Figure 8 It is a vertical cross-sectional view of the sleeve cup in the embodiment of the button-type lithium manganese battery of the utility model. DETAILED DESCRIPTION

[0031] In the following description, many specific details are described to facilitate a full understanding of the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below. In the following embodiments, the negative electrode side is at the top and the positive electrode side is at the bottom.

[0032] The button-type lithium manganese battery of the embodiment is as follows Figure 1As shown, it includes a positive electrode 10, a negative electrode 20, a diaphragm 30 and a sealing ring 40; wherein the positive electrode 10 includes a positive electrode cup shell 11, a positive electrode active cake 12 and a current collecting net 13, the positive electrode active cake 12 is arranged in the positive electrode cup shell 11, and the current collecting net 13 is located between the positive electrode cup shell 11 and the positive electrode active cake 12; the negative electrode 20 includes a negative electrode cup cover 21 and a negative electrode active cake 22 arranged in the negative electrode cup cover 21; wherein the sealing ring 40 is located between the negative electrode cup cover 21 and the positive electrode cup shell 11 to perform a circumferential connection between the two; the diaphragm 30 is located between the negative electrode active cake 22 and the positive electrode active cake 12.

[0033] The negative electrode cup cover 21 is preferably made of 304 stainless steel sheet, 316 stainless steel sheet, 430 stainless steel sheet or new type of gradient annealing anti-rust iron sheet. Preferably, the sheet thickness of the negative electrode 20 cover cup is generally between 0.10 and 0.50 mm, preferably 0.25 and 0.30 mm. The outer ring diameter and height of the negative electrode 20 cover cup are determined according to the designed outer diameter of the battery. In order to increase hardness and rust prevention, the surface of the sheet used to manufacture the negative electrode 20 cover cup can preferably be treated with surface treatment, such as chemical electroplating and physical vapor sputtering treatment; wherein, the anti-corrosion layer provided on the surface of the negative electrode cup cover 21 can be a nickel layer, a titanium layer, a silver layer, a gold layer, or a thin sheet anti-corrosion layer can be compositely rolled into a clip, and the composite rolling can be heating the sheet and composite molding through a rolling machine, or it can be directly rolled without heating; then, the sheet is punched into a disc through a forming hardware mold, and then pushed into a forming mold, and the upper and lower molds are combined to form and release, so as to obtain a sheet as shown in the figure. Figure 2 The negative electrode cup cover 21 is shown.

[0034] Specifically, the negative electrode cup cover 21 has a top wall 211, a folded peripheral wall 212 and a transition connecting wall 213, wherein the transition connecting wall 213 connects the top wall 211 and the folded peripheral wall 212 respectively; wherein the top wall 211 is planar, and the folded peripheral wall 212 is U-shaped, including a folded outer wall 2121 and a folded inner wall 2122, and the folded outer wall 2121 and the folded inner wall 2122 overlap. Preferably, the transition connecting wall 213 is an arc-shaped wall, which has two continuous transition R-angle connection positions 214, and is connected to the top wall 211 and the folded peripheral wall 212 respectively through the two transition R-angle connection positions 214.

[0035] Furthermore, the top wall 211 of the negative electrode cup cover 21 is in a constricted shape; wherein, the outer edge diameter of the top wall 211 is generally retracted by a distance of less than 1.0 mm compared to the diameter of the folded peripheral wall 212. Preferably, compared to the folded peripheral wall 212, the outer edge diameter of the top wall 211 is retracted by a distance of 1.5-3 times the thickness of the negative electrode cup cover 21, specifically, for example, 2 times, that is, when the thickness of the negative electrode cup cover 21 (specifically, the thickness of the sheet material making the negative electrode cup cover 21) is 0.3 mm, the outer edge diameter of the top wall 211 is retracted by a distance of 0.6 mm.

[0036] The sealing ring 40 is preferably made of an anti-corrosion material that is resistant to acid, alkali and organic solvents, such as polypropylene, polyphenylene sulfide, polyetheretherketone and the like, which are modified to be strong plastics; specifically, the sealing ring 40 is formed by a hot injection mold; Figure 3 As shown, the longitudinal section of the sealing ring 40 is U-shaped, and it has a bottom 41 and a sealing inner wall 42 and a sealing outer wall 43 located on opposite sides of the bottom 41, and a groove portion 44 is formed between the sealing inner wall 42 and the sealing outer wall 43, and the groove portion 44 is used to accommodate the folded peripheral wall 212; wherein, the inner surface of the sealing outer wall 43 is in contact with the folded outer wall 2121 of the folded peripheral wall 212; further, the groove bottom of the groove portion 44 is adjacent to the sealing outer wall 43. A recess 45 has a width that is the same as the width of the folded peripheral wall 212 so as to cooperate with the folded peripheral wall 212 to provide guidance for the installation of the sealing ring 40.

[0037] The positive electrode cup shell 11 is preferably made of 304 stainless steel sheet, 316 stainless steel sheet, 430 stainless steel sheet or new type of gradient annealing anti-rust iron sheet. Preferably, the sheet thickness of the positive electrode cup shell 11 is generally between 0.10 and 0.50 mm, preferably 0.25 and 0.30 mm. The outer ring diameter and height of the positive electrode cup shell 11 are determined according to the designed outer diameter of the battery. In order to increase hardness and rust prevention, the surface of the sheet used to prepare the positive electrode cup shell 11 can preferably be treated with surface treatment, such as chemical electroplating and physical vapor sputtering treatment; wherein, the anti-corrosion layer arranged on the surface of the positive electrode cup shell 11 can be a nickel layer, a titanium layer, a silver layer, a gold layer, or a thin sheet anti-corrosion layer can be compositely rolled into a clip, and the composite rolling can be heating the sheet and composite molding through a rolling machine, or it can be directly rolled without heating; then, the sheet is punched into a disc through a forming hardware mold, and then pushed into a forming mold, and the upper and lower molds are combined to form and release, so as to obtain a sheet as shown in the figure. Figure 4 The positive electrode cup 11 is shown.

[0038] Specifically, the positive electrode cup shell 11 has a cup bottom 111 and a cup outer wall 112; the cup bottom 111 is flat, and the cup outer wall 112 is slightly expanded before sealing; wherein, when the sealing ring 40 is installed in the positive electrode cup shell 11, the top of the cup outer wall 112 is preferably flush with the top of the sealing outer wall 43.

[0039] The current collecting net 13 is preferably made of 304 stainless steel sheet, 316 stainless steel sheet, 430 stainless steel sheet or new type of gradient annealing anti-rust iron sheet; in order to increase hardness and rust prevention, the surface of the sheet used to prepare the current collecting net 13 can preferably be surface treated, such as chemical electroplating and physical vapor sputtering treatment; wherein, the anti-corrosion layer arranged on the surface of the current collecting net 13 can be a nickel layer, a titanium layer, a silver layer, a gold layer, or a thin sheet anti-corrosion layer can be compositely rolled into a clip, and the composite rolling can be heating the sheet and then compositely forming it through a rolling machine, or it can be directly composited without heating; then, by cutting, the following can be obtained: Figure 5 The current collecting net 13 shown is provided with a plurality of current collecting meshes 131, wherein the shape of the current collecting meshes 131 can be a rhombus, a square or a triangle, etc. In an optional embodiment, the current collecting net 13 can also be obtained by weaving, which will not be expanded here.

[0040] An exemplary preparation process of the button-type lithium manganese battery in the embodiment is: first, a circular flat negative electrode active cake 22 is placed in the negative electrode cup cover 21 and fits with the inner surface of the top wall 211 of the negative electrode cup cover 21, and a diaphragm 30 is placed in the negative electrode cup cover 21 and fits with the negative electrode active cake 22; wherein the diaphragm 30 is preferably a bowl-shaped diaphragm 30 with an opening at the bottom.

[0041] Next, electrolyte is added to the diaphragm 30 . After the filling is completed, the positive electrode active cake 12 is placed on the diaphragm 30 and fits with the diaphragm 30 . The positive electrode active cake 12 can be pre-soaked with saturated electrolyte or electrolyte can be directly added to the positive electrode active cake 12 .

[0042] Then, the current collecting net 13 is placed on the center of the surface of the positive electrode active cake 12 away from the diaphragm 30; at the same time, the sealing ring 40 is placed on the folded outer peripheral wall 212 of the negative electrode cup cover 21 and the lower edge of the diaphragm 30 is kept intersecting with the sealing ring 40 to prevent the positive electrode 10 cake activity from contacting the inner surface of the negative electrode cup cover 21 and causing an internal short circuit; wherein, the intersection length between the lower edge of the diaphragm 30 and the sealing ring 40 is preferably set to be not less than 0.5mm, for example, the intersection length is 1mm to 3mm, specifically 1.5mm.

[0043] Finally, the above-mentioned combination is put into the positive electrode cup shell 11 and tightly combined together. In a dry environment with a low dew point below -45°C, the opening part of the positive electrode cup shell 11 is radially retracted into the molding die to fix the parts and achieve a tight buckle seal (in this process, the cup outer wall 112 of the positive electrode cup shell 11 and the sealing outer wall 43 of the sealing ring 40 are deformed and pressed against the transition connection wall 213 of the negative electrode cup cover 21) to obtain the button-type lithium manganese battery of the embodiment.

[0044] The negative electrode active cake 22 of the embodiment is an effective active material for negative electrode electrical energy, for example, battery-grade high-purity lithium, and lithium aluminum alloy and lithium magnesium alloy that can improve lithium molding can also be used; the separator 30 is a thin sheet that separates the active materials of the positive and negative electrodes 20, and is made of materials that are resistant to corrosion by organic solvent immersion, such as polypropylene, polyphenylene sulfide, polyetheretherketone, polytetrafluoroethylene, glass fiber, etc. The positive electrode active cake 12 is an effective active material for positive electrode electrical energy, and its main components are, for example, a mixture of manganese dioxide, a conductive agent and a binder, wherein the manganese dioxide can be a phase-changed β electrolytic manganese dioxide or a direct phase-changed chemical β manganese dioxide.

[0045] Furthermore, the negative electrode active cake 22 is in close contact with the negative electrode cup cover 21, the positive electrode active cake 12 is in close contact with the positive electrode cup shell 11 through the current collecting net 13, and the other internal composition planes are closely attached to each other. The electrolyte wets each positive and negative electrode 20 and the diaphragm 30 to form an electrochemical electrolytic cell inside. When the external positive and negative electrodes 20 are turned on, the internal ions are converted and output high-power energy through the electromotive force ion movement.

[0046] The positive electrode active cake 12 of the embodiment is a combination, which includes a sleeve cup 121 and a positive electrode active material 122 pressed and formed in the sleeve cup 121. The sleeve cup 121 has good conductivity and structural stability, and can protect the positive electrode active material 122 from bursting during the discharge process.

[0047] The sleeve cup 121 is preferably made of 304 stainless steel sheet, 316 stainless steel sheet, 430 stainless steel sheet or new type of gradient annealing anti-rust iron sheet; in order to increase hardness and rust resistance, the surface of the sheet used to prepare the sleeve cup 121 can preferably be surface treated, such as chemical electroplating and physical vapor sputtering treatment; wherein, the anti-corrosion layer arranged on the surface of the sleeve cup 121 can be a nickel layer, a titanium layer, a silver layer, a gold layer, or a thin sheet anti-corrosion layer can be compositely rolled into a clip, and the composite rolling can be heating the sheet and composite molding through a rolling machine, or it can be directly rolled without heating; then, the sheet is punched and sheared into a disc through a forming hardware mold, and then pushed into a forming mold, and the upper and lower molds are combined to form the mold and then released.

[0048] In the prior art, the pressing and molding process of the positive electrode active material 122 and the sleeve cup 121 is usually to place the round cake-shaped positive electrode active material 122 directly in the sleeve cup 121, and press the two together tightly through a mold and a punch; however, the sleeve cup 121 has a large space area inside, and the positive electrode active material 122 is prone to uneven overall force during the pressing and molding process, resulting in uneven force release, making the density of the positive electrode active material 122 at various positions uneven, especially at the edge position close to the bottom 111 wall of the sleeve cup 121, this phenomenon is more obvious; the positive electrode active cake 12 obtained by the above pressing and molding is prone to poor flatness or even slight bending after the positive electrode active material 122 absorbs the electrolyte, which leads to a decrease in the tightness of the fit between the positive electrode active material 122 and the sleeve cup 121, resulting in a decrease in current density and ultimately affecting the output voltage and power.

[0049] To solve the above problem, the sleeve cup 121 of the embodiment has a bottom wall 1211 and a convex thorn portion 1212 disposed on the bottom wall 1211 and facing the positive electrode active material 122, such as Figure 6As shown, when the positive electrode active material 122 is pressed and molded into the sleeve cup 121, the convex thorn portion 1212 is inserted into the positive electrode active material 122. In the embodiment, the positive electrode active material 122 is pressed and molded into the sleeve cup 121 by using a top pressing mold and a bottom pressing mold; illustratively, a convex needle portion is provided on the bottom wall 1211 of the sleeve cup 121, and when the positive electrode active material 122 is pressed and molded into the sleeve cup 121, the convex needle acts on the bottom wall 1211 of the sleeve cup 121 to deform the bottom wall 1211 of the sleeve cup 121 to form a convex thorn portion 1212 facing the positive electrode active material 122, and at the same time, the convex thorn portion 1212 is inserted into the positive electrode active material 122. Specifically, the convex thorn portion 1212 can be through-through from top to bottom, or it can be closed. In an optional embodiment, the burr portion 1212 may also be prefabricated directly on the bottom wall 1211 , for example, pre-formed on the upper surface of the bottom wall 1211 facing the positive electrode active material 122 by welding.

[0050] The burr portion 1212 preferably has a conical structure with a small upper end and a large lower end, such as a truncated cone, a triangular truncated cone, and a quadrangular truncated cone; further, the height of the burr portion 1212 is set to 1 / 5 to 1 / 2 of the total height of the positive electrode active cake 12, and the height of the burr portion 1212 is specifically, for example, 1 / 3 of the total height of the positive electrode active cake 12; the setting of the burr portion 1212 can not only better fix the positive electrode active material 122, but also increase the effect of current collection and energy enrichment when the chemical energy of the positive electrode active material 122 is converted into electrical energy; at the same time, the presence of the burr portion 1212 can also achieve uniform force release when the positive electrode active material 122 is pressed and formed into the sleeve cup 121, so that the positive electrode active material 122 remains flat after absorbing the electrolyte to achieve close contact with the plane, thereby increasing the current density while achieving the stability of the voltage power supply and the increase of the output power.

[0051] In addition, the burr portion 1212 is inserted into the positive active material 122 during the molding stage of the positive active cake 12, which can maintain the stability of the structure of the positive active cake 12; at the same time, the outer surface of the bottom 111 wall of the sleeve cup 121 in the positive active cake 12 remains planar, which is conducive to its fit with the current collecting network 13, thereby increasing the current density to achieve the stability of the voltage power supply and the increase of the output power.

[0052] Furthermore, the burr portion 1212 preferably has a plurality of edge burrs, and the plurality of edge burrs are preferably distributed in a circular array; wherein the plurality of edge burrs can directly promote uniform force release in the outer edge region of the positive electrode active material 122 during the pressing and molding process, which is beneficial to maintaining uniform density of the positive electrode active material 122 at various positions; in an optional embodiment, the burr portion 1212 also has a plurality of central burrs, and the plurality of central burrs are formed in the central region of the bottom wall 1211 as required to cooperate with the edge burrs to achieve uniform force release of the positive electrode active material 122.

[0053] In this embodiment, the bottom wall 1211 also has a through hole portion, and when the positive electrode active material 122 is pressed and formed into the sleeve cup 121, the positive electrode active material 122 is filled into the hole portion to achieve the force release at the corresponding position; specifically, the hole portion includes a central hole position 1213 and edge holes 1214, and the number of edge holes 1214 is multiple, and the multiple edge holes 1214 are arranged in an array or in pairs relative to the central hole position 1213, for example Figure 7 Eight edge apertures 1214 are shown arranged in an array.

[0054] Among them, the center hole 1213 is relatively large, and the center hole 1213 is preferably a circular hole, and its diameter is preferably 1 / 10-2 / 5 of the diameter of the bottom wall 1211, and the diameter of the center hole 1213 is specifically, for example, 1 / 4 of the diameter of the bottom wall 1211; the edge hole 1214 is relatively small, and the edge hole 1214 is also preferably a circular hole, and the diameter of the edge hole 1214 is preferably 2 / 5-3 / 5 of the diameter of the center hole 1213, and the diameter of the edge hole 1214 is specifically, for example, 1 / 2 of the diameter of the center hole 1213. In other embodiments, the shapes of the center hole 1213 and the edge hole 1214 can also be other shapes such as square, which will not be expanded here; preferably, the center hole 1213 is set not to exceed the current collecting net 13, that is, the current collecting net 13 can completely cover the center hole 1213 in the horizontal plane.

[0055] Furthermore, a recessed pattern region 1215 is provided on the upper surface of the bottom wall 1211 of the embodiment facing the positive electrode active material 122, and the positive electrode active material 122 is filled into the recessed pattern region 1215 when the positive electrode active material 122 is pressed and formed into the sleeve cup 121. The pattern shape of the recessed pattern region 1215 includes one or more of a square, a rectangle, a triangle or a circle, for example Figure 7 Several arrays of square patterns are shown; in other embodiments, other regular or irregular patterns may be provided as required, which will not be elaborated here.

[0056] Although the present invention is described above through embodiments, it should be understood that the above embodiments are only used to exemplarily describe the feasible implementation methods of the present invention, and should not be interpreted as limiting the scope of protection of the present invention. That is, any replacement or change made by those skilled in the art in accordance with the present invention should also be covered by the scope of protection of the claims of the present invention.

Claims

1. A button-type lithium manganese battery, characterized in that: Including positive and negative electrodes, diaphragms and sealing rings; The positive electrode comprises a positive electrode cup shell, a positive electrode active cake disposed in the positive electrode cup shell, and a current collecting net located between the positive electrode cup shell and the positive electrode active cake; the positive electrode active cake comprises a sleeve cup and a positive electrode active material pressed and formed in the sleeve cup; The negative electrode comprises a negative electrode cup cover and a negative electrode active cake arranged in the negative electrode cup cover; The sealing ring is located between the negative electrode cup cover and the positive electrode cup shell to connect the two in a circumferential manner; the diaphragm is located between the negative electrode active cake and the positive electrode active cake; The negative electrode cup cover has a top wall, a folded peripheral wall and a transition connecting wall; the transition connecting wall is an arc-shaped wall, which has two continuous transition R-angle connecting positions, and the two transition R-angle connecting positions of the transition connecting wall are respectively connected to the top wall and the folded peripheral wall; wherein, the top wall of the negative electrode cup cover is in a constricted shape, and the outer edge diameter of the top wall is less than 2 mm indented compared to the folded peripheral wall.

2. The button-type lithium manganese battery according to claim 1, characterized in that: The outer edge diameter of the top wall is retracted by less than 1 mm compared to the outer peripheral wall of the folded edge.

3. The button-type lithium manganese battery according to claim 1, characterized in that: The sheet thickness of the negative electrode cover cup is 0.10 mm to 0.50 mm; wherein the indentation distance of the outer edge diameter of the top wall compared to the folded edge peripheral wall is 1.5-3 times the sheet thickness of the negative electrode cup cover.

4. The button-type lithium manganese battery according to claim 3, characterized in that: The indentation distance of the outer edge diameter of the top wall compared with the outer peripheral wall of the folded edge is twice the thickness of the sheet material of the negative electrode cup cover.

5. The button-type lithium manganese battery according to claim 3, characterized in that: The sheet thickness of the negative electrode cover cup is 0.20 mm to 0.30 mm.

6. The button-type lithium manganese battery according to claim 1, characterized in that: The diaphragm is a bowl-shaped diaphragm with an opening at the bottom; wherein the lower edge of the diaphragm intersects with the sealing ring, and the intersection length between the lower edge of the diaphragm and the sealing ring is set to be no less than 0.5 mm.

7. The button-type lithium manganese battery according to claim 1, characterized in that: The sleeve cup has a bottom wall and a convex thorn portion arranged on the bottom wall, and the convex thorn portion is arranged to be inserted into the positive electrode active material.

8. The button-type lithium manganese battery according to claim 7, characterized in that: The burr portion is assembled on the bottom wall or formed as one piece with the bottom wall.

9. The button-type lithium manganese battery according to claim 7, characterized in that: The bottom wall has a through hole, and the positive electrode active material is filled into the hole when the positive electrode active material is compression-molded in the sleeve cup.

10. The button-type lithium manganese battery according to claim 7, characterized in that: The bottom wall is provided with a concave pattern area on the upper surface facing the positive electrode active material, and the positive electrode active material is filled into the concave pattern area when the positive electrode active material is pressed and formed into the sleeve cup.

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