Lithium manganese dioxide battery and preparation method of battery cell of lithium manganese dioxide battery

Abstract

The invention relates to the field of batteries, and particularly discloses a lithium manganese dioxide battery and a preparation method of a battery cell of the lithium manganese dioxide battery, the battery comprises a winding type battery cell, and the winding type battery cell comprises a manganese dioxide positive plate, a negative plate and a diaphragm; the manganese dioxide positive plate is wound, the diaphragm wraps the outer side of the manganese dioxide positive plate, and the negative belt wraps the outer side of the diaphragm; the negative electrode strip comprises a negative electrode lithium strip and a copper strip, and the copper strip is pressed on the negative electrode lithium strip. The copper strip is pressed on the negative electrode lithium strip to form the negative electrode strip, and the copper strip cannot be broken when the battery vibrates, so that the functions of collecting and conducting electrons can be maintained, the negative electrode strip can provide enough energy, a unique winding form is combined, the thickness of the negative electrode lithium strip is increased, the structural strength of the negative electrode lithium strip is improved, and the service life of the battery is prolonged when the battery vibrates. Therefore, the anti-seismic property of the winding type battery cell is improved, and the anti-seismic property of the lithium-manganese dioxide battery is further improved.

Description

Technical Field

[0001] The present invention relates to the field of batteries, and particularly to a lithium manganese dioxide battery and a preparation method for its battery core. Background Art

[0002] Lithium manganese dioxide batteries are widely used in various electronic devices due to their high energy density, low self-discharge rate, long life, and safety. The existing lithium manganese dioxide batteries with wound battery cores include manganese dioxide positive electrode sheets and lithium negative electrode sheets. The positive electrode sheet, separator, and negative electrode sheet are wound synchronously. The lithium negative electrode sheet has poor earthquake resistance. Therefore, the existing lithium manganese dioxide batteries, especially in the discharge scenarios of small and medium currents, have the problem of insufficient earthquake resistance. Summary of the Invention

[0003] The present invention provides a lithium manganese dioxide battery and a preparation method for its battery core, aiming to solve the problem of insufficient earthquake resistance of the existing lithium manganese dioxide batteries.

[0004] In a first aspect, the present invention discloses a lithium manganese dioxide battery, including a wound battery core. The wound battery core includes a manganese dioxide positive electrode sheet, a negative electrode strip, and a separator. The manganese dioxide positive electrode sheet is wound. The separator is wrapped outside the manganese dioxide positive electrode sheet. The negative electrode strip is wrapped outside the separator. The negative electrode strip includes a negative lithium strip and a copper strip. The copper strip is pressed on the negative lithium strip.

[0005] In some embodiments, the thickness of the negative lithium strip is 1 mm.

[0006] In some embodiments, the particle size D50 of the manganese dioxide particles in the manganese dioxide positive electrode sheet is 8 - 10 microns.

[0007] In some embodiments, the particle size D50 of the manganese dioxide particles in the manganese dioxide positive electrode sheet is 9 microns.

[0008] In some embodiments, the copper strip extends along the length direction of the negative lithium strip.

[0009] In some embodiments, the long axis center line of the copper strip and the long axis center line of the negative lithium strip are arranged on the same straight line.

[0010] In some embodiments, the short axis center line of the copper strip and the short axis center line of the negative lithium strip are arranged on the same straight line.

[0011] In some embodiments, the lithium manganese dioxide battery further includes a metal shell, an electrolyte, and a sealing cap group. The metal shell is used to accommodate the wound battery core and the electrolyte. The sealing cap group is welded to the metal shell.

[0012] In some embodiments, the separator is a three-layer adhesive structure of PP+PE+PP.

[0013] In a second aspect, the present invention also discloses a method for preparing an electrode assembly, which is used to prepare the wound electrode assembly described in the first aspect, and includes:

[0014] Providing a manganese dioxide positive electrode sheet and winding the manganese dioxide positive electrode sheet;

[0015] Before the winding of the manganese dioxide positive electrode sheet reaches the end, inserting the separator inside the manganese dioxide positive electrode sheet;

[0016] Winding the separator and the remaining manganese dioxide positive electrode sheet;

[0017] Providing a negative lithium strip, and pressing a copper strip on the negative lithium strip to obtain a negative electrode strip;

[0018] Wrapping the negative electrode strip outside the separator to obtain a wound electrode assembly.

[0019] Advantages of the present invention: A lithium manganese dioxide battery and a method for preparing an electrode assembly thereof disclosed by the present invention. The battery includes a wound electrode assembly, and the wound electrode assembly includes a manganese dioxide positive electrode sheet, a negative electrode strip, and a separator; the manganese dioxide positive electrode sheet is wound, the separator is wrapped outside the manganese dioxide positive electrode sheet, and the negative electrode strip is wrapped outside the separator; the negative electrode strip includes a negative lithium strip and a copper strip, and the copper strip is pressed on the negative lithium strip. By pressing a copper strip on the negative lithium strip to form a negative electrode strip, when the battery vibrates, the copper strip will not break, so that its function of collecting and conducting electrons can be maintained, ensuring that the negative electrode strip can provide sufficient energy, and combining with a unique winding form, increasing the thickness of the negative lithium strip and improving its structural strength. When the battery vibrates, the negative lithium strip will not break either, thereby improving the seismic performance of the wound electrode assembly and further improving the seismic performance of the lithium manganese dioxide battery. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 It is a longitudinal sectional view of the lithium manganese dioxide battery provided by the embodiment of the present invention;

[0022] Figure 2 It is a sectional view of the wound electrode assembly of the lithium manganese dioxide battery provided by the embodiment of the present invention;

[0023] Figure 3Schematic plan view of welding the positive electrode tab to the manganese dioxide positive electrode sheet of the lithium manganese dioxide battery provided by the embodiment of the present invention;

[0024] Figure 4 Schematic plan view of welding the negative electrode tab to the negative electrode belt of the lithium manganese dioxide battery provided by the embodiment of the present invention.

[0025] Reference numerals in the drawings: 1, manganese dioxide positive electrode sheet; 2, negative electrode belt; 201, negative lithium belt; 202, copper belt; 3, positive electrode tab; 4, negative electrode tab; 5, separator; 6, metal casing; 7, electrolyte; 8, sealing cap group; 9, steel ball; 10, cap group pole column; 11, cap; 12, insulating washer; 13, first top insulating gasket; 14, second top insulating gasket; 15, bottom insulating gasket. Detailed implementation manners

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] It should be understood that when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0028] It should also be noted that unless otherwise clearly defined and limited, terms such as "installed", "connected", "connected", "fixed", "set" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located above the other element, or there may also be one or more intermediate elements. The terms "first", "second", "third", etc. are only for the convenience of describing the technical solution of the present application, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first", "second", "third", etc. may explicitly or implicitly include one or more of such features. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] It should also be understood that the terms used in the specification of the present invention are merely for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0030] It should be further understood that the terms "and / or" used in the specification of the present invention and the appended claims refer to any combination and all possible combinations of one or more of the associated listed items, and include these combinations.

[0031] As Figures 1 to 4 shown, an embodiment of the present invention discloses a lithium manganese dioxide battery. Figure 1 It is a schematic longitudinal sectional view of the lithium manganese dioxide battery provided by the embodiment of the present invention. Figure 2 It is a schematic sectional view of the wound battery core of the lithium manganese dioxide battery provided by the embodiment of the present invention. Figure 3 It is a schematic plan view of the manganese dioxide positive electrode sheet of the lithium manganese dioxide battery provided by the embodiment of the present invention welding the positive electrode tab. Figure 4 It is a schematic plan view of the negative electrode strip of the lithium manganese dioxide battery provided by the embodiment of the present invention welding the negative electrode tab.

[0032] Referring together to Figures 1 to 4 , an embodiment of the present invention discloses a lithium manganese dioxide battery, which includes a wound battery core. The wound battery core includes a manganese dioxide positive electrode sheet 1, a negative electrode strip 2 and a separator 5. The manganese dioxide positive electrode sheet 1 is wound, the separator 5 is wrapped outside the manganese dioxide positive electrode sheet 1, and the negative electrode strip 2 is wrapped outside the separator 5. The negative electrode strip 2 includes a negative lithium strip 201 and a copper strip 202, and the copper strip 202 is pressed on the negative lithium strip 201.

[0033] In this embodiment, the positive electrode of the battery includes a manganese dioxide positive electrode sheet 1, and the negative electrode of the battery includes a negative electrode strip 2. When the battery discharges, the manganese dioxide on the manganese dioxide positive electrode sheet 1 receives electrons from the external circuit and combines with the lithium ions in the electrolyte 7 to form lithium manganate as an oxidant. The stable crystal structure of lithium manganate ensures the smooth discharge of the battery. The material of the negative lithium strip 201 is lithium metal or lithium alloy, such as Li-Al, Li-Sn, Li-Pb, etc. When the battery discharges, the lithium atoms on the negative lithium strip 201 lose electrons and are oxidized to form lithium ions, and release electrons to the external circuit to provide energy. The copper strip 202 serves as a current collector conductive carrier for collecting and conducting electrons. The separator 5 is located between the manganese dioxide positive electrode sheet 1 and the negative electrode strip 2, and mainly functions to isolate the positive and negative electrodes and prevent short circuits.

[0034] On the one hand, the copper strip 202 has excellent ductility and seismic resistance. When the battery vibrates, the copper strip 202 will not break, so that its function of collecting and conducting electrons can be maintained, ensuring that the negative electrode strip 2 can provide sufficient energy. The discharge curve of the battery provided in this embodiment is very stable in voltage throughout the discharge cycle, and the effect is particularly obvious at the end of the discharge capacity. In the lithium manganese dioxide battery in the prior art, the lithium negative electrode sheet has poor seismic resistance. When the battery vibrates, the lithium negative electrode sheet is prone to breakage, resulting in a rapid drop in voltage. On the other hand, in this embodiment, since the copper strip 202 is pressed on the negative lithium strip 201, the strength of the negative lithium strip 201 is also improved, and the seismic resistance of the negative lithium strip 201 itself is enhanced. When the battery vibrates, the negative lithium strip 201 itself will not break. Therefore, the design of pressing the copper strip 202 on the negative lithium strip 201 can effectively improve the seismic resistance of the lithium manganese dioxide battery.

[0035] Furthermore, the winding form of the wound core in this embodiment is different from that of the traditional wound core. The traditional wound core is to synchronously wind the positive electrode sheet, the separator, and the negative electrode sheet into a cylindrical shape. In this embodiment, the manganese dioxide positive electrode sheet 1 is first wound separately into a cylinder, then the separator 5 is wrapped around the outside of the manganese dioxide positive electrode sheet 1, and finally the negative electrode strip 2 is wrapped around the outside of the separator 5. The length of the negative electrode strip 2 is approximately equal to the outermost circumference of the wound manganese dioxide positive electrode sheet 1. The unique winding form of this embodiment can increase the thickness of the negative electrode strip 2 without increasing the size of the battery case. The reason is as follows: In the traditional wound core, due to synchronous winding, for each winding cycle, the radius of the core will increase by the thickness of one layer of positive electrode sheet, one layer of negative electrode sheet, and one layer of separator. If a total of A winding cycles are required, the radius of the core is approximately equal to A times the sum of the thicknesses of one layer of positive electrode sheet, one layer of negative electrode sheet, and one layer of separator. If the manganese dioxide positive electrode sheet 1 of the wound core in this embodiment is also wound A times, the radius of the core is only approximately equal to A times the thickness of one layer of manganese dioxide positive electrode sheet 1 plus the thickness of one layer of separator 5 and the thickness of one layer of negative electrode strip 2. Therefore, assuming that the wound core in this embodiment has the same size as the traditional wound core, the negative electrode strip 2 in this embodiment can be set thicker. Furthermore, the negative lithium strip 201 can be set thicker, thereby enhancing the structural strength of the negative lithium strip 201 to improve its seismic resistance.

[0036] In summary, in this embodiment, the negative electrode lithium strip 201 is laminated with a copper strip 202 to form a negative electrode strip 2, and combined with a unique winding form, the seismic performance of the wound battery cell is improved, thereby improving the seismic performance of the lithium manganese dioxide battery, enabling it to operate stably in a harsh mechanical environment. Moreover, in this embodiment, the seismic performance can be improved without increasing the battery size. The lithium manganese dioxide battery in this embodiment has a stable voltage platform (especially in the later stage of battery discharge) and high discharge efficiency in medium and small current discharge scenarios, and is applicable to various low-power electronic devices, such as smoke alarms.

[0037] In one embodiment, the thickness of the negative electrode lithium strip 201 is 1 mm.

[0038] In this embodiment, when the size is the same as that of a lithium manganese dioxide battery of a certain traditional wound battery cell, the thickness of its negative electrode sheet can only reach 0.16 mm, while the thickness of the negative electrode lithium strip 201 in this embodiment is 1 mm. By improving the strength of the negative electrode lithium strip 201 and combining it with the copper strip 202, the seismic performance of the lithium manganese dioxide battery is significantly improved.

[0039] In one embodiment, the particle size D50 of the manganese dioxide particles of the manganese dioxide positive electrode sheet 1 is 8 - 10 microns.

[0040] The particle size D50 means: the particle size corresponding to when the cumulative particle size distribution percentage of a sample reaches 50%. Its physical meaning is that 50% of the particles are larger than it and 50% of the particles are smaller than it. In this embodiment, controlling the particle size D50 of the manganese dioxide particles to the range of 8 - 10 microns, specifically 8 microns, 8.5 microns, 9 microns, 9.5 microns or 10 microns, can effectively increase the active area of the electrode reaction. Compared with traditional lithium manganese dioxide batteries, the battery capacity can be increased by 5% - 10%.

[0041] The reason is that manganese dioxide particles with a particle size D50 of 8 - 10 microns have a relatively high specific surface area (surface area per unit mass), can provide more reaction sites, and at the same time can avoid agglomeration caused by too small particles or difficulty in electrolyte penetration. The disadvantages of particle size D50 > 10 microns: the specific surface area decreases, the particles are too large resulting in a reduction in the active area and insufficient reaction sites, leading to an increase in the diffusion distance of lithium ions inside the particles and an increase in polarization when combining with lithium ions to form lithium manganate. The disadvantages of particle size D50 < 8 microns: too small particles are prone to agglomeration, and the actual active area is instead reduced. Therefore, controlling the particle size D50 of the manganese dioxide particles to 8 - 10 microns can effectively increase the active area of the electrode reaction and improve the battery capacity.

[0042] In one embodiment, the copper strip 202 extends along the length direction of the negative electrode lithium strip 201.

[0043] Further, the long-axis center line of the copper strip 202 and the long-axis center line of the negative lithium strip 201 are arranged on the same straight line.

[0044] Further, the short-axis center line of the copper strip 202 and the short-axis center line of the negative lithium strip 201 are also arranged on the same straight line.

[0045] In this embodiment, after the copper strip 202 is pressed onto the negative lithium strip 201 along the length direction of the negative lithium strip 201, its length is the same as that of the negative lithium strip 201. Thus, after the battery cell is wound and formed, the copper strip 202 completely surrounds one week to ensure that the negative lithium strip 201 can provide sufficient energy through its current collecting function.

[0046] In one embodiment, the lithium manganese dioxide battery further includes a metal shell 6, an electrolyte 7, and a sealing cover group 8; the metal shell 6 is used to accommodate the wound battery cell and the electrolyte 7, and the sealing cover group 8 is welded to the metal shell 6.

[0047] In this embodiment, the metal shell 6 can be made of a nickel-plated steel shell, which is cylindrical on the outside and has an opening at the top. The wound battery cell after winding can be placed into the metal shell 6 through the opening. The sealing cover group 8 is welded to the metal shell 6 to close the opening. A liquid injection hole is provided on the sealing cover group 8, and the electrolyte 7 can be injected into the metal shell 6 through the liquid injection hole. The main functions of the metal shell 6 and the sealing cover group 8 are to encapsulate the internal components of the battery, protect the internal structure and materials of the battery, prevent external moisture, air, etc. from polluting and corroding the inside of the battery, and at the same time prevent substances such as the electrolyte 7 inside the battery from leaking. In addition, the metal shell 6 also serves as the negative electrode lead-out terminal of the battery, playing a role in conducting electricity and providing a physical connection for the electrical energy output of the battery. The electrolyte 7 is a medium for the transmission of lithium ions between the positive and negative electrodes. It can provide a transmission channel for lithium ions, enabling the electrochemical reaction inside the battery to proceed smoothly. The lithium manganese dioxide battery further includes a steel ball 9, which is used to seal the liquid injection hole after injection to prevent the electrolyte 7 from leaking.

[0048] In one embodiment, the wound battery cell further includes a positive electrode tab 3 and a negative electrode tab 4. One end of the positive electrode tab 3 is welded to the manganese dioxide positive electrode sheet 1, and the other end is welded to the cover group terminal post 10. One end of the negative electrode tab 4 is welded to the negative strip 2, and the other end is welded to the metal shell 6.

[0049] In this embodiment, the positive electrode tab 3 is made of a stainless steel strip, and the negative electrode tab 4 is made of a nickel strip. The functions of the positive electrode tab 3 and the negative electrode tab 4 are to collect the current on the electrodes (positive electrode and negative electrode) and conduct it out / import it, so as to realize the electrical connection between the battery and the external circuit. The cover group pole column 10 passes through the sealing cover group 8, one end of which is located inside the sealing cover group 8, and the other end is located outside the sealing cover group 8. The end of the positive electrode tab 3 far from the manganese dioxide positive electrode sheet 1 is welded to the end of the cover group pole column 10 located inside the sealing cover group 8. The lithium manganese dioxide battery further includes a cap 11, which is arranged outside the sealing cover group 8, and the inner side of the cap 11 is welded to the end of the cover group pole column 10 located outside the sealing cover group 8. In this way, the cap 11 can be used as the positive electrode lead-out end of the battery to connect to the external circuit and output the electrical energy of the battery to external devices. The end of the negative electrode tab 4 far from the negative electrode strip 2 is welded to the inner side wall of the metal shell 6, so that the metal shell 6 serves as the negative electrode lead-out end of the battery.

[0050] Specifically, the manganese dioxide positive electrode sheet 1 is in a longitudinally long rectangular shape. When the positive electrode tab 3 is welded to the manganese dioxide positive electrode sheet 1, it is welded at a position 50 mm from one end of the manganese dioxide positive electrode sheet 1. And when winding, it is preferably wound starting from the end close to the positive electrode tab 3. Thus, after winding, the positive electrode tab 3 is located at the middle of the cylindrical manganese dioxide positive electrode sheet 1.

[0051] In one embodiment, the separator 5 is a three-layer bonding structure of PP (polypropylene) + PE (polyethylene) + PP. Arranged in the winding manner provided in the above embodiment, the separator 5 is arranged between the manganese dioxide positive electrode sheet 1 and the negative electrode strip 2. Its main function is to isolate the positive electrode and the negative electrode, prevent electrons from passing through and avoid short circuits, while allowing lithium ions to pass through, so as to realize ion conduction and maintain the normal operation of the battery on the premise of ensuring battery safety.

[0052] In one embodiment, the lithium manganese dioxide battery further includes an insulating washer 12, a first top insulating gasket 13, a second top insulating gasket 14, and a bottom insulating gasket 15.

[0053] In this embodiment, an insulating washer 12 is disposed on the outer end face of the seal cover group 8 for isolating the cap 11 from the seal cover group 8. Since the periphery of the seal cover group 8 is welded to the metal housing 6, isolating the cap 11 from the seal cover group 8 is equivalent to isolating the cap 11 from the metal housing 6, thus preventing the cap 11 from contacting the metal housing 6 and causing a short circuit. A first top insulating gasket 13 is disposed on the inner end face of the seal cover group 8, and the first top insulating gasket 13 is in close contact with the periphery of the cap group terminal 10. The insulating washer 12 is also in close contact with the periphery of the cap group terminal 10. An insulating member (not labeled in the figure) is also disposed at the overlapping position of the cap group terminal 10 and the seal cover group 8 to prevent the cap group terminal 10 from contacting the seal cover group 8 and causing a short circuit. Moreover, the first top insulating gasket 13 also prevents the positive electrode tab 3 from contacting the seal cover group 8 and causing a short circuit. A second top insulating gasket 14 is disposed on the top of the wound manganese dioxide positive electrode sheet 1 and covers the entire top end face thereof, thus preventing the top of the manganese dioxide positive electrode sheet 1 from contacting the inner side wall surface of the metal housing 6 and causing a short circuit. A bottom insulating gasket 15 is disposed at the bottom of the wound manganese dioxide positive electrode sheet 1 to prevent the bottom of the manganese dioxide positive electrode sheet from contacting the inner bottom wall surface of the metal housing 6 and causing a short circuit.

[0054] An embodiment of the present invention further provides a method for manufacturing an electric core for manufacturing the wound electric core described in the above embodiment, including:

[0055] Providing a manganese dioxide positive electrode sheet and winding the manganese dioxide positive electrode sheet;

[0056] Before the winding of the manganese dioxide positive electrode sheet reaches the end, inserting a separator into the inside of the manganese dioxide positive electrode sheet;

[0057] Winding the separator and the remaining manganese dioxide positive electrode sheet;

[0058] Providing a negative lithium strip and laminating a copper strip on the negative lithium strip to obtain a negative strip;

[0059] Wrapping the negative strip outside the separator to obtain a wound electric core.

[0060] In one embodiment, providing the manganese dioxide positive electrode sheet includes:

[0061] Grinding manganese dioxide particles to control their particle size D50 within the range of 8 - 10 microns; mixing the ground manganese dioxide particles with a conductive agent and a binder, and roll-pressing them on an aluminum mesh; after drying and secondary roll-pressing, obtaining a manganese dioxide positive electrode sheet.

[0062] In one embodiment, before winding the manganese dioxide positive electrode sheet, it includes: welding the positive electrode tab to the manganese dioxide positive electrode sheet at a position 50 mm from one end of the manganese dioxide positive electrode sheet. When winding the manganese dioxide positive electrode sheet, start winding from the end close to the positive electrode tab.

[0063] In one embodiment, before the manganese dioxide positive electrode sheet is wound to the end, inserting a separator inside the manganese dioxide positive electrode sheet includes: when there is still 50 - 55 mm left at the tail of the manganese dioxide positive electrode sheet, inserting the separator inside the manganese dioxide positive electrode sheet.

[0064] In one embodiment, before wrapping the negative electrode strip outside the separator, it includes: welding the negative electrode tab to the negative electrode strip.

[0065] An embodiment of the present invention further provides a preparation method of a lithium manganese dioxide battery for preparing the lithium manganese dioxide battery described in the above embodiment, including:

[0066] Providing a metal casing, and placing a bottom insulating gasket at the bottom inside the metal casing;

[0067] Assembling the wound type battery cell prepared in the above embodiment into the metal casing;

[0068] Placing a second top insulating gasket on the top of the wound type battery cell;

[0069] Providing a combination of a cap, a sealing cap group, a cap group pole, an insulating washer, and a first top insulating gasket;

[0070] Welding the positive electrode tab to the cap group pole, and welding the negative electrode tab to the metal casing;

[0071] Pressing the combination into the metal casing, and laser - welding the combination and the metal casing;

[0072] Injecting electrolyte from the liquid injection hole, and using a steel ball to seal the liquid injection hole;

[0073] Performing a discharge aging treatment to obtain the lithium manganese dioxide battery.

[0074] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A lithium manganese dioxide battery, characterized in that, It includes a wound cell, and the wound cell includes a manganese dioxide positive electrode sheet, a negative electrode strip, and a separator; the manganese dioxide positive electrode sheet is wound, the separator is wrapped outside the manganese dioxide positive electrode sheet, and the negative electrode strip is wrapped outside the separator; the negative electrode strip includes a negative lithium strip and a copper strip, and the copper strip is pressed on the negative lithium strip.

2. The lithium manganese dioxide battery according to claim 1, characterized in that, The thickness of the negative lithium strip is 1 mm.

3. The lithium manganese dioxide battery according to claim 1, characterized in that, The particle size D50 of the manganese dioxide particles in the manganese dioxide positive electrode sheet is 8-10 microns.

4. The lithium manganese dioxide battery according to claim 3, characterized in that, The particle size D50 of the manganese dioxide particles in the manganese dioxide positive electrode sheet is 9 microns.

5. The lithium manganese dioxide battery according to claim 1, characterized in that, The copper strip extends along the length direction of the negative lithium strip.

6. The lithium manganese dioxide battery according to claim 4, wherein The long axis center line of the copper strip and the long axis center line of the negative lithium strip are arranged on the same straight line.

7. The lithium manganese dioxide battery according to claim 6, characterized in that, The short axis center line of the copper strip and the short axis center line of the negative lithium strip are arranged on the same straight line.

8. The lithium manganese dioxide battery according to claim 1, characterized in that, The lithium manganese dioxide battery further includes a metal shell, an electrolyte, and a sealing cover group; the metal shell is used to accommodate the wound cell and the electrolyte, and the sealing cover group is welded to the metal shell.

9. The lithium manganese dioxide battery according to claim 1, characterized in that, The separator is a three-layer bonding structure of PP+PE+PP.

10. A method for preparing an electrode assembly, which is used to prepare the wound electrode assembly according to any one of claims 1 to 9, characterized in that, It includes: Providing a manganese dioxide positive electrode sheet and winding the manganese dioxide positive electrode sheet; Before the winding of the manganese dioxide positive electrode sheet reaches the end, inserting the separator inside the manganese dioxide positive electrode sheet; Winding the separator and the remaining manganese dioxide positive electrode sheet; Providing a negative lithium strip and pressing a copper strip on the negative lithium strip to obtain a negative electrode strip; Wrapping the negative electrode strip outside the separator to obtain a wound cell.

Images