A separator for a lithium-manganese primary battery, its preparation method, and the lithium-manganese primary battery and power-consuming device.

Abstract

This invention belongs to the field of battery technology and provides a separator for a lithium manganese primary battery, its preparation method, the lithium manganese primary battery, and an electrical device thereof. The separator includes a fiber membrane layer containing organic fibers, and the fiber membrane layer has pores in which a first solid electrolyte is disposed. The separator also includes a base membrane layer disposed on both sides of the fiber membrane layer. By combining organic fibers with a solid electrolyte to form a fiber membrane layer, the fiber membrane layer can improve the mechanical strength and toughness of the separator, effectively preventing battery short circuits or failures caused by mechanical deformation, while also increasing the overall liquid absorption and retention capacity of the separator.

Description

Technical Field

[0001] This invention belongs to the field of battery technology and relates to a separator for a lithium manganese primary battery, its preparation method, the lithium manganese primary battery and the power-consuming device. Background Technology

[0002] Lithium-manganese dioxide primary batteries (referred to as lithium manganese primary batteries) are high-reliability non-rechargeable power sources. In their internal structure, the separator is a key non-active component that undertakes the core functions of isolating the positive and negative electrodes, preventing short circuits, and allowing lithium ions to migrate freely.

[0003] Currently, commercial lithium-manganese batteries commonly use polyolefin microporous membranes (such as polypropylene (PP) or polyethylene (PE)) as separator materials. While these materials possess good chemical inertness, electronic insulation, and a certain porosity, they still have significant drawbacks in practical applications. Especially during battery assembly, transportation, or use, the separator must withstand multiple mechanical forces, including winding tension, electrode surface punctures, and thermal stress. Existing polyolefin separators suffer from insufficient molecular chain rigidity and limited crystallinity, resulting in low mechanical strength and weak puncture resistance. When sharp edges exist on the surface of the positive electrode manganese dioxide particles or tiny protrusions exist on the surface of the negative electrode lithium sheet, the separator is prone to rupture or perforation in areas of localized stress concentration, causing direct contact between the positive and negative electrodes and triggering internal micro-short circuits. These micro-short circuits not only lead to abnormally high battery self-discharge rates and rapid capacity decay, but in severe cases, they can trigger exothermic reactions, causing thermal runaway and even fire risks. Furthermore, during high-temperature storage or discharge, polyolefin separators may experience thermal shrinkage, further reducing their dimensional stability and exacerbating the short-circuit risk.

[0004] Current technologies have not effectively resolved the contradiction between insufficient mechanical strength of separators and the high safety requirements of batteries. This is especially true under the trend of high-load, high-density electrode designs, which place even stricter demands on the puncture resistance and dimensional stability of separators. Therefore, developing novel separator structures that combine high mechanical strength, excellent thermal stability, and good ion conductivity has become a key technological challenge for improving the safety and reliability of lithium-manganese dioxide primary batteries. Summary of the Invention

[0005] In view of the problems existing in the prior art, the purpose of this invention is to provide a separator for a lithium manganese primary battery, its preparation method, a lithium manganese primary battery, and an electrical device thereof. The separator includes a fiber membrane layer containing organic fibers, and the fiber membrane layer has pores in which a first solid electrolyte is disposed. The separator also includes a base membrane layer disposed on both sides of the fiber membrane layer. By combining organic fibers with a solid electrolyte to form a fiber membrane layer, the fiber membrane layer can improve the mechanical strength and toughness of the separator, effectively preventing battery short circuits or failures caused by mechanical deformation, and also increasing the overall liquid absorption and retention capacity of the separator.

[0006] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a separator for a lithium manganese primary battery, comprising a fiber membrane layer containing organic fibers, wherein the fiber membrane layer has pores and a first solid electrolyte is disposed in the pores; the separator further comprises a base membrane layer disposed on both sides of the fiber membrane layer.

[0007] This invention utilizes the high strength and high modulus of organic fibers to form a fiber membrane layer, making the membrane more robust when subjected to internal battery stress, effectively preventing battery short circuits or failures caused by mechanical deformation. Simultaneously, filling the pores of the fiber membrane layer with a solid electrolyte acts as a filler and supporting material for the membrane, further enhancing its mechanical strength. Furthermore, the excellent liquid absorption capacity of organic fibers increases the liquid absorption rate of the membrane, effectively improving the ion transport rate.

[0008] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The technical objectives and beneficial effects of the present invention can be better achieved and realized through the following technical solutions.

[0009] As a preferred technical solution of the present invention, the organic fibers in the fiber membrane layer include at least one of aramid fibers, polyester fibers, polyamide fibers, polyphenylene sulfide fibers, or polyethylene terephthalate fibers.

[0010] Preferably, the length of the organic fiber ranges from 2 mm to 10 mm, and the diameter ranges from 0.1 μm to 10 μm. Exemplarily, the length of the organic fiber can be 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm, etc.; the diameter can be 0.1 μm, 0.3 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm, etc., preferably 0.1 μm to 2 μm.

[0011] In this invention, the organic fibers have small diameters, large specific surface areas, and a greater number of hydrophilic surfaces. Three-dimensional micropores are formed between the fibers, allowing for liquid absorption through capillary action. Among them, the aramid fibers possess hydrophilic amide functional groups, which further enhance their liquid absorption capacity. In this invention, the aspect ratio of the organic fibers affects the tensile strength, puncture strength, and high-temperature dimensional stability of the finished diaphragm. The length should be adjusted according to actual needs to achieve the optimal aspect ratio, ensuring that the diameter is suitable for forming liquid-retaining capacity and adequate pores to accommodate the first solid electrolyte.

[0012] Preferably, the thickness of the fiber membrane layer is 1 μm to 10 μm. Exemplarily, the thickness of the fiber membrane layer can be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm, etc.

[0013] In this invention, the thickness of the fiber membrane layer affects the final total thickness of the finished separator. On the one hand, as the separator thickness increases, the ion transport distance increases, and the battery's pulse discharge capability decreases. On the other hand, the separator thickness is an important factor affecting strength, influencing the safety performance of the battery cell and the smoothness of the assembly process. Moreover, the battery cell design needs to consider the core size, thus requiring the total separator thickness to be limited to a certain range. Therefore, under the premise that the fiber membrane layer can play its role in improving mechanical strength and toughness as well as liquid absorption and retention capabilities, the thickness of the fiber membrane layer and the total thickness of the separator should be reasonably controlled.

[0014] Preferably, the pore size in the fiber membrane layer is 1μm to 20μm, and the porosity is 60% to 90%. Exemplarily, the pore size in the fiber membrane layer can be 1μm, 3μm, 5μm, 8μm, 10μm, 12μm, 14μm, 16μm, 18μm, or 20μm, preferably 1μm to 5μm; the porosity can be 60%, 65%, 70%, 75%, 80%, 85%, or 90%, etc.

[0015] As a preferred embodiment of the present invention, the fiber membrane layer further includes an adhesive.

[0016] Preferably, the adhesive comprises at least one of acrylates, polyvinyl alcohols, polyurethanes, epoxy resins, or silicones.

[0017] Preferably, the adhesive content accounts for 1% to 5% of the mass of the organic fiber. For example, the proportion of adhesive can be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, etc.

[0018] As a preferred embodiment of the present invention, the material of the base film layer includes PP and / or PE.

[0019] Preferably, the thickness of the base film layer is 4 μm to 9 μm. Exemplarily, the thickness of the base film layer can be 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, or 9 μm, etc. Considering that a fiber membrane layer is provided in this invention, a base film layer with a smaller thickness can optionally be used to control the total thickness of the diaphragm.

[0020] Preferably, the pore size in the base film layer is 20nm~200nm, and the porosity is 40%~50%. For example, the pore size in the base film layer can be 20nm, 40nm, 60nm, 80nm, 100nm, 120nm, 140nm, 160nm, 180nm, or 200nm, etc.; the porosity can be 60%, 65%, 70%, 75%, 80%, 85%, or 90%, etc.

[0021] As a preferred embodiment of the present invention, the membrane further includes a solid electrolyte layer; the solid electrolyte layer is disposed on the side of the base membrane layer away from the fiber membrane layer; the solid electrolyte layer contains a second solid electrolyte.

[0022] Preferably, the second solid electrolyte comprises an oxide solid electrolyte.

[0023] Preferably, the thickness of the solid electrolyte layer is 0.5 μm to 2 μm. Exemplarily, the thickness of the solid electrolyte layer can be 0.5 μm, 0.8 μm, 1 μm, 1.2 μm, 1.5 μm, 1.8 μm, or 2 μm, etc.

[0024] Preferably, the method for preparing the solid electrolyte layer includes preparing a coating slurry by mixing a second solid electrolyte with a solvent, coating it, and then drying it to form a solid electrolyte layer.

[0025] Preferably, the solvent comprises water and / or N-methylpyrrolidone.

[0026] Preferably, the solid content of the coating slurry is 90% to 98%, for example, it can be 90%, 92%, 94%, 96% or 98%, etc.

[0027] Preferably, the drying temperature is 60℃~120℃, for example, it can be 60℃, 70℃, 80℃, 90℃, 100℃, 110℃ or 120℃, etc., and a continuous segmented forced-air drying oven can be used optionally.

[0028] As a preferred embodiment of the present invention, the particle size of the first solid electrolyte ranges from 0.3 μm to 2 μm, for example, it can be 0.3 μm, 0.5 μm, 0.8 μm, 1 μm, 1.3 μm, 1.5 μm, 1.8 μm, or 2 μm. Therefore, matching the particle size with the diameter of the organic fibers facilitates the filling of the first solid electrolyte into the pores of the fiber network formed by the organic fibers.

[0029] As a preferred technical solution of the present invention, the mass ratio of the first solid electrolyte to the organic fiber is (1~4):1, for example, it can be 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1 or 4:1, etc.

[0030] Preferably, the loading of the first solid electrolyte is 3 g / m³. 2 ~5g / m 2 For example, it could be 3g / m 2 3.5g / m 2 4g / m 2 4.5g / m 2 or 5g / m 2 wait.

[0031] As a preferred technical solution of the present invention, the solid electrolyte includes an oxide solid electrolyte.

[0032] When the first solid electrolyte or the second solid electrolyte of the present invention includes an oxide solid electrolyte, the oxide solid electrolyte may include at least one of garnet-type solid electrolyte, NASION-type solid electrolyte, or perovskite-type solid electrolyte.

[0033] Preferably, the garnet-type solid electrolyte comprises LLZO and / or LLZTO.

[0034] Preferably, the NASION-type solid electrolyte includes at least one of LATP, LAGP, or LZSP.

[0035] Preferably, the perovskite-type solid electrolyte includes LLTO.

[0036] Preferably, the first solid electrolyte or the second solid electrolyte is independently selected from at least one of LLZO, LLZTO, LLTO or LATP.

[0037] In a second aspect, the present invention provides a method for preparing the separator of the lithium manganese primary battery as described in the first aspect, the method comprising: Prepare organic fibers, adhesives, and a base film layer; Organic fibers, adhesives, and solvents are formulated into a suspension slurry. The suspension slurry is then laid flat, dried, and hot-pressed sequentially to obtain a porous dry membrane layer. The dry membrane layer is then mixed with a solid electrolyte, which fills the pores to obtain a fiber membrane layer. A base film layer is placed on both sides of the fiber film layer, and the film is rolled and laminated at a temperature higher than the softening temperature of the base film layer to obtain a separator.

[0038] As a preferred embodiment of the present invention, the solvent includes N-methylpyrrolidone and / or dimethyl sulfoxide.

[0039] Preferably, the solid content of the suspension slurry is 10g / 100g to 40g / 100g. Exemplarily, the solid content can be 10g / 100g, 15g / 100g, 18g / 100g, 20g / 100g, 23g / 100g, 25g / 100g, 28g / 100g, 30g / 100g, 33g / 100g, 35g / 100g, 38g / 100g, or 40g / 100g, etc.

[0040] Preferably, the drying temperature is 80℃~90℃. For example, the drying temperature can be 80℃, 82℃, 84℃, 86℃, 88℃, or 90℃, etc.

[0041] Preferably, the pressure of the roller pressing is 0.3MPa to 7MPa, for example, it can be 0.3MPa, 0.5MPa, 0.8MPa, 1MPa, 1.3MPa, 1.5MPa, 1.8MPa, 2MPa, 2.5MPa, 3MPa, 4MPa, 5MPa, 6MPa or 7MPa, and more preferably 0.3MPa to 2MPa.

[0042] Preferably, the base film layer can be obtained by stretching methods, such as dry stretching of PP base film, wet stretching of PE film, etc.

[0043] Thirdly, the present invention provides a lithium manganese primary battery, wherein the lithium manganese primary battery contains the separator described in the first aspect.

[0044] It is understood that, in addition to the separator, the lithium manganese primary battery also includes a positive electrode, a negative electrode, and an electrolyte; the separator is disposed between the positive electrode and the negative electrode.

[0045] For example, the positive electrode sheet includes a positive current collector and a positive active layer disposed on the positive current collector. The positive active layer contains the positive active material manganese dioxide, and the positive active layer also includes a binder and / or a conductive agent.

[0046] Preferably, the conductive agent includes at least one of graphite, conductive carbon black, acetylene black, graphene, or carbon nanotubes.

[0047] Preferably, the adhesive comprises at least one of polytetrafluoroethylene, styrene-butadiene rubber, ethylene-acrylic acid copolymer, or polyvinylidene fluoride and its modifiers.

[0048] Preferably, based on the mass of the positive electrode active layer as 100%, the mass percentage of the positive electrode active material is 88%~92%, such as 88%, 88.5%, 88.8%, 89%, 89.2%, 89.6%, 90%, 90.3%, 90.6%, 91%, 91.2%, 91.5%, or 92%; the mass percentage of the conductive agent is 6%~8%, such as 6%, 6.2%, 6.4%, 6.6%, 6.8%, 7%, 7.2%, 7.4%, 7.6%, 7.8%, or 8%; and the mass percentage of the binder is 2%~4%, such as 2%, 2.3%, 2.5%, 2.8%, 3.2%, 3.5%, 3.8%, or 4%.

[0049] Preferably, the positive current collector includes steel mesh, aluminum mesh, etc.

[0050] Preferably, the negative electrode comprises lithium metal or a lithium alloy.

[0051] Preferably, the doped metal element in the lithium alloy includes at least one of aluminum, magnesium or calcium; based on the total mass of the lithium metal anode as 100%, the mass percentage of the doped metal element is 0.05% to 3%, for example 0.05%, 0.08%, 0.1%, 0.13%, 0.15%, 0.18% or 0.3%.

[0052] Preferably, the electrolyte is typically an organic electrolyte, including lithium salts and organic solvents.

[0053] Preferably, the lithium salt includes at least one of LiClO4, LiFSI, LiBOB, or LiTFSI.

[0054] Preferably, the organic solvent includes at least one selected from ethylene carbonate, butyl carbonate, diethyl carbonate, methyl ethyl carbonate, 1,2-dimethoxyethane, or 1,2-diethoxyethane.

[0055] Preferably, the electrolyte injection volume is 0.12 g / Ah to 0.2 g / Ah, such as 0.12 g / Ah, 0.13 g / Ah, 0.14 g / Ah, 0.15 g / Ah, 0.16 g / Ah, 0.17 g / Ah, 0.18 g / Ah, 0.19 g / Ah, or 0.2 g / Ah.

[0056] As a preferred technical solution of the present invention, the lithium manganese primary battery includes any one of button cell, cylindrical cell, or pouch cell, preferably a cylindrical cell.

[0057] Fourthly, the present invention provides an electrical device comprising the lithium manganese primary battery described in the third aspect.

[0058] It should be noted that, due to space limitations and to avoid redundancy, this invention does not exhaustively list all point values ​​within the above numerical range, but it is not limited to the listed values ​​either; other unlisted values ​​within the above numerical range are also applicable.

[0059] Compared with existing technical solutions, the present invention has at least the following beneficial effects: In the lithium-manganese primary battery separator of this invention, the high strength and high modulus of organic fibers are used to form a fiber membrane layer, making the separator more robust when subjected to internal battery stress and effectively preventing short circuits or battery failures caused by mechanical deformation. Simultaneously, solid electrolyte is filled into the pores of the fiber membrane layer, acting as a filler and supporting material for the separator, further enhancing its mechanical strength. Furthermore, the excellent liquid absorption capacity of organic fibers increases the liquid absorption rate of the separator, effectively improving the ion transport rate. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the layer structure of the separator in one or more embodiments of a lithium manganese primary battery.

[0061] In the diagram: 1-fiber membrane layer, 2-base membrane layer, 3-solid electrolyte layer. Detailed Implementation

[0062] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0063] Those skilled in the art will understand that the embodiments described are merely illustrative of the invention and should not be construed as limiting the invention.

[0064] Example 1 This embodiment provides a separator for a lithium manganese primary battery, such as... Figure 1 As shown, the membrane includes a fiber membrane layer 1 containing organic fibers, and the fiber membrane layer 1 has pores in which a first solid electrolyte is disposed; the membrane also includes a base membrane layer 2, which is disposed on both sides of the fiber membrane layer 1. The organic fibers in the fiber membrane layer 1 are aramid fibers with a length ranging from 2 mm to 5 mm and a diameter ranging from 0.1 μm to 2 μm; the thickness of the fiber membrane layer 1 is 10 μm; the pore size of the pores in the fiber membrane layer 1 ranges from 1 μm to 5 μm, and the porosity is 80%; the fiber membrane layer 1 also includes an adhesive, which is an acrylate, and the content of the adhesive accounts for 2.5% of the mass of the organic fibers; The first solid electrolyte is an oxide solid electrolyte (LLZO) with a particle size range of 0.3 μm to 2 μm; The base film layer 2 is a dry-stretched PP film with a thickness of 5 μm, and the pore size in the base film layer 2 is 20 nm to 200 nm, with a porosity of 45%. The membrane further includes a solid electrolyte layer 3; the solid electrolyte layer 3 is disposed on the side of the base membrane layer 2 away from the fiber membrane layer 1; the solid electrolyte layer 3 contains a second solid electrolyte, the second solid electrolyte including an oxide solid electrolyte LLZO, and the thickness of the solid electrolyte layer 3 is 2 μm.

[0065] This embodiment also provides a method for preparing a separator for a lithium manganese primary battery, the method comprising: Prepare organic fibers, adhesives, and a base film layer; Organic fibers, adhesives, and solvent water are mixed to form a suspension slurry with a solid content of 25g / 100g. The suspension slurry is spread evenly on an iron mesh to form a uniform film layer. After drying at 85℃, it is hot-pressed to control the thickness and porosity of the film layer, resulting in a dry film layer with pores. Then, the dry film layer is mixed with a solid electrolyte, so that the solid electrolyte fills the pores to obtain a fiber film layer. A base film layer is placed on both sides of the fiber film layer, and roll pressing is performed at a temperature higher than the softening temperature of the base film layer (typically, the softening temperature of PP film is 105℃~120℃ and the softening temperature of PE film is 80℃~90℃). In this embodiment, a functional PP film is used as the base film layer, so roll pressing is performed at 122℃ to obtain a composite film. Then, the second solid electrolyte and the solvent N-methylpyrrolidone are mixed to form a coating slurry with a solid content of 95%. The slurry is coated on both sides of the composite membrane and dried at 80°C to form a solid electrolyte layer, thus obtaining the diaphragm.

[0066] Example 2 This embodiment provides a separator for a lithium manganese primary battery, wherein the thickness of the fiber membrane layer 1 is adjusted from 10 μm to 4 μm, and all other conditions are exactly the same as in Embodiment 1.

[0067] Example 3 This embodiment provides a separator for a lithium manganese primary battery, wherein the thickness of the fiber membrane layer 1 is adjusted from 10 μm to 7 μm. Except for the above, the other conditions are exactly the same as in Embodiment 1.

[0068] Example 4 This embodiment provides a separator for a lithium manganese primary battery, wherein the thickness of the fiber membrane layer 1 is adjusted from 10 μm to 20 μm, and all other conditions are exactly the same as in Embodiment 1.

[0069] Example 5 This embodiment provides a separator for a lithium manganese primary battery, wherein the porosity of the fiber membrane layer 1 is adjusted from 80% to 40%, and all other conditions are exactly the same as in Embodiment 1.

[0070] Example 6 This embodiment provides a separator for a lithium manganese primary battery, wherein the porosity of the fiber membrane layer 1 is adjusted from 80% to 60%, and all other conditions are exactly the same as in Embodiment 1.

[0071] Example 7 This embodiment provides a separator for a lithium manganese primary battery, wherein the porosity of the fiber membrane layer 1 is adjusted from 80% to 90%, and all other conditions are exactly the same as in Embodiment 1.

[0072] Example 8 This embodiment provides a separator for a lithium manganese primary battery, in which both the first solid electrolyte and the second solid electrolyte are replaced with LLTO instead of LLZO. Except for the above, the other conditions are exactly the same as in Embodiment 1.

[0073] Example 9 This embodiment provides a separator for a lithium manganese primary battery, in which both the first solid electrolyte and the second solid electrolyte are replaced with LLZTO instead of LLZO. Except for the above, the other conditions are exactly the same as in Embodiment 1.

[0074] Example 10 This embodiment provides a separator for a lithium manganese primary battery. The outer side of the base film layer 2 in the separator does not have a solid electrolyte layer 3. Except for the above, the other conditions are exactly the same as in Embodiment 1.

[0075] Comparative Example 1 This comparative example provides a separator for a lithium manganese primary battery, wherein the pores in the fiber membrane layer 1 of the separator are not provided with a first solid electrolyte, and all other conditions are exactly the same as in Example 1.

[0076] Comparative Example 2 This comparative example provides a separator for a lithium manganese primary battery, in which the first solid electrolyte filling the pores in the fiber membrane layer 1 of the separator is replaced with inorganic particles Al2O3. Except for the above, the other conditions are exactly the same as in Example 1.

[0077] Comparative Example 3 This comparative example provides a separator for a lithium manganese primary battery, which does not have a fiber membrane layer 1, but only uses a base membrane layer 2 with a thickness of 20 μm. Solid electrolyte layers 3 are provided on both sides of this base membrane layer 2. Except for the above, the other conditions are exactly the same as those in Example 1.

[0078] Characterization and Testing I. The following tests were performed on the diaphragms obtained in the examples and comparative examples: 1) Mechanical strength: The tensile strength of the diaphragm was tested according to the standard method GB / T 1040.3-2006; 2) Heat shrinkage rate test: Cut a 100mm×100mm diaphragm piece, place it at 150℃ for 1 hour, and then test the heat shrinkage rate of the diaphragm. 3) Diaphragm electrolyte wettability test: Cut a 100mm×100mm diaphragm, drop 0.1mL of electrolyte into the center of the diaphragm, and test the diffusion diameter of the electrolyte within 1 minute; 4) Membrane ionic conductivity: Cut a 20mm diameter membrane disc and immerse it in electrolyte at room temperature for 20 minutes until the membrane pores are completely filled. Place the membrane into a CR2032 battery mold in a glove box and assemble the battery using stainless steel sheets as electrodes. Use an electrochemical workstation to test the impedance and ionic conductivity of the simulated battery.

[0079] II. A positive electrode, a negative electrode, a separator, and an electrolyte are provided; the positive electrode includes a positive current collector aluminum foil and a positive active layer disposed thereon, the positive active layer containing 90% by mass of positive active material manganese dioxide, 6% by mass of conductive agent graphite, and 4% by mass of binder polyvinylidene fluoride; the negative electrode is lithium metal; the electrolyte includes a lithium salt and an organic solvent; the lithium salt is LiFSI, and the organic solvent is ethylene carbonate; the separators obtained in the examples and comparative examples are assembled with the above-mentioned positive electrode, negative electrode, electrolyte, and other components to form various lithium-manganese primary batteries, and the following tests are performed: 1) Continuous pulse test: The battery is continuously discharged at 10mA with a 3s on and 3s off pulse discharge at 85℃ for a continuous discharge time of 16h, with a load voltage ≥2.0V throughout the process.

[0080] 2) High temperature shock test: The battery is stored at 105℃ for 24 hours, the separator shrinkage rate is <20%, and the load voltage (150Ω, 0.2s) decreases by ≤0.3V.

[0081] The results of all the above tests are shown in Table 1 and Table 2.

[0082] Table 1 Table 2 Combining Table 1 and Table 2, we can see that: Comparing Example 1 with Comparative Examples 1 and 3, Example 1 shows that by sandwiching a fiber membrane layer in the center of the base membrane and filling the pores of the fiber membrane layer with a solid electrolyte, the liquid absorption surface of the separator can be increased. The high specific surface area of ​​the fibers and LLZO particles enhances the adsorption capacity of the separator, and the high ionic conductivity of LLZO increases the continuous discharge voltage of the battery in low electrolyte conditions. This indicates that incorporating a solid electrolyte in the fiber membrane layer can improve the electrolyte wettability and ionic conductivity of the separator.

[0083] Comparing Example 1 with Comparative Example 2, conventional Al2O3 ceramics are non-conductive and mainly improve the conductivity of the separator by adsorbing electrolyte through surface pores. In contrast, oxide solid electrolytes have a certain conductivity. Under similar powder pore size, oxide solid electrolytes significantly improve the ionic conductivity of the separator and the minimum continuous discharge voltage of the battery.

[0084] Comparing Example 1 with Examples 2 to 4, the fibers are mechanically wound and glued together to form a fiber web. The increased thickness of the fiber membrane layer helps to improve the mechanical strength of the separator, making it more resistant to internal shrinkage stress during high-temperature impact, avoiding short circuits between the positive and negative electrodes of the battery, and improving the safety of the battery.

[0085] Comparing Example 1 with Examples 5-7, the porosity of the fiber membrane layer affects the electrolyte storage space. Membranes with high porosity have better liquid absorption and faster electrolyte diffusion. In high-porosity membranes, the tortuosity of ion migration paths is reduced, resulting in higher ionic conductivity. Increased porosity is beneficial for improving the ionic conductivity of the membrane and the minimum continuous pulse voltage of the battery.

[0086] Comparing Example 1 with Examples 8 and 9 shows that the ionic conductivity of LLZO, LLTO, and LLZTO is similar, and the minimum continuous pulse voltage of the three oxide solid electrolyte schemes is similar, but LLTO and LLZTO have Ti 4+ Ions are easily reduced and cannot come into direct contact with metallic lithium. Therefore, their use should be avoided on the outer side of the base film layer in lithium-manganese battery systems.

[0087] As can be seen from the above, in the separator of the lithium manganese primary battery described in this invention, the high strength and high modulus of organic fibers form a fiber membrane layer, making the separator more robust when subjected to internal battery stress. The separator exhibits lower shrinkage during high-temperature shock testing, effectively preventing short circuits or battery failures caused by mechanical deformation. Simultaneously, filling the pores of the fiber membrane layer with solid electrolyte allows it to act as a filler and supporting material for the separator, further enhancing its mechanical strength. Furthermore, the excellent liquid absorption capacity of organic fibers increases the liquid absorption rate of the separator, effectively improving the ion transport rate.

[0088] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0089] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0090] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A separator for a lithium manganese primary battery, characterized in that, The membrane includes a fiber membrane layer containing organic fibers, and the fiber membrane layer has pores in which a first solid electrolyte is disposed; the membrane also includes a base membrane layer disposed on both sides of the fiber membrane layer.

2. The separator for a lithium manganese primary battery according to claim 1, characterized in that, The organic fibers in the fiber membrane include at least one of aramid fibers, polyester fibers, polyamide fibers, polyphenylene sulfide fibers, or polyethylene terephthalate fibers. Preferably, the organic fiber has a length ranging from 2 mm to 10 mm and a diameter ranging from 0.1 μm to 10 μm, more preferably from 0.1 μm to 2 μm. Preferably, the thickness of the fiber membrane layer is 1 μm to 10 μm; Preferably, the pore size of the pores in the fiber membrane layer is 1μm~20μm, more preferably 1μm~5μm, and the porosity is 60%~90%.

3. The separator for a lithium manganese primary battery according to claim 1 or 2, characterized in that, The fiber membrane layer also includes an adhesive; Preferably, the adhesive comprises at least one of acrylates, polyvinyl alcohol, polyurethane, epoxy, or silicone. Preferably, the adhesive content accounts for 1% to 5% of the mass of the organic fiber.

4. The separator for a lithium manganese primary battery according to any one of claims 1-3, characterized in that, The base film layer is made of PP and / or PE; Preferably, the thickness of the base film layer is 4μm to 9μm; Preferably, the pore size of the pores in the base film layer is 20nm~200nm, and the porosity is 40%~50%.

5. The separator for a lithium manganese primary battery according to any one of claims 1-4, characterized in that, The membrane further includes a solid electrolyte layer; the solid electrolyte layer is disposed on the side of the base membrane layer away from the fiber membrane layer; the solid electrolyte layer contains a second solid electrolyte; Preferably, the second solid electrolyte comprises an oxide solid electrolyte; Preferably, the thickness of the solid electrolyte layer is 0.5 μm to 2 μm.

6. The separator for a lithium manganese primary battery according to claim 5, characterized in that, The first solid electrolyte includes an oxide solid electrolyte; Preferably, the oxide solid electrolyte includes at least one of garnet-type solid electrolyte, NASION-type solid electrolyte, or perovskite-type solid electrolyte; Preferably, the garnet-type solid electrolyte comprises LLZO and / or LLZTO; Preferably, the NASION-type solid electrolyte includes at least one of LATP, LAGP, or LZSP; Preferably, the perovskite solid electrolyte comprises LLTO; Preferably, the particle size range of the first solid electrolyte is 0.3 μm to 2 μm; Preferably, the mass ratio of the first solid electrolyte to the organic fiber is (1~4):

1.

7. A method for preparing a separator for a lithium manganese primary battery according to any one of claims 1-6, characterized in that, The preparation method includes: Prepare organic fibers, adhesives, and a base film layer; Organic fibers, adhesives, and solvents are formulated into a suspension slurry. The suspension slurry is then laid flat, dried, and hot-pressed sequentially to obtain a porous dry membrane layer. The dry membrane layer is then mixed with a solid electrolyte, which fills the pores to obtain a fiber membrane layer. A base film layer is placed on both sides of the fiber film layer, and the film is rolled and laminated at a temperature higher than the softening temperature of the base film layer to obtain a separator.

8. The method for preparing the separator of a lithium manganese primary battery according to claim 7, characterized in that, The solvent includes dimethyl sulfoxide and / or N-methylpyrrolidone; Preferably, the solid content of the suspension slurry is 10g / 100g to 40g / 100g; Preferably, the drying temperature is 80℃~90℃; Preferably, the pressure of the roller pressing composite is 0.3MPa~7MPa.

9. A lithium-manganese primary battery, characterized in that, It contains the diaphragm according to any one of claims 1-6.

10. An electrical appliance, characterized in that, It contains the lithium manganese primary battery as described in claim 9.

Images